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Sample records for 3d borehole seismic

  1. 3D seismic imaging around the 2.5 km deep COSC-1 scientific borehole, central Sweden

    Hedin, Peter; Juhlin, Christopher; Buske, Stefan

    2015-04-01

    Following the successful completion of the COSC-1 drilling campaign, a number of geophysical investigations have been performed in and around the 2.5 km deep borehole. Three different seismic experiments were conducted simultaneously in the fall of 2014 to take advantage of the same source points; 1) a Vertical Seismic Profile (VSP) in the borehole, 2) three 2D seismic profiles across the borehole, and 3) a limited 3D seismic survey (presented here). The latter is the first 3D seismic survey on land in Scandinavia to target the Caledonian Nappes and will allow mapping a small part of the Seve Nappe Complex (SNC) in 3D. Furthermore, it will allow extrapolation of results from downhole logging, core analysis and other seismic surveys to structures surrounding the borehole. A total number of 429 receivers (10 Hz single component geophones) were planted with 20 m separation along 7 lines spaced 200 m apart. The total area with receivers covered approximately 1.5 km2 and was centered on the drill site. A combination of a mechanical source (a rock breaking hydraulic hammer, near offsets) and explosive charges (0.5 kg fired at 3.5 - 5 m depth, far offsets) were used. The source points were activated along roads radiating outwards from the COSC-1 drill site in a star pattern. The nominal shot spacing was 20 m (vibrating source) or 80 m (explosives) and maximum horizontal offset was about 5.75 km. The high-grade metamorphic SNC is well known from previous 2D seismic studies to be a highly reflective unit. However, due to the complex 3D geometry and lithological variation within the unit, it has not been clearly imaged. The new 3D data provide a means to image these structures in more detail and to follow the lithological and structural interfaces observed in the core into the surrounding unit. Preliminary results from the 3D processing and correlation with borehole data will be presented.

  2. A Robust MEMS Based Multi-Component Sensor for 3D Borehole Seismic Arrays

    Paulsson Geophysical Services

    2008-03-31

    The objective of this project was to develop, prototype and test a robust multi-component sensor that combines both Fiber Optic and MEMS technology for use in a borehole seismic array. The use such FOMEMS based sensors allows a dramatic increase in the number of sensors that can be deployed simultaneously in a borehole seismic array. Therefore, denser sampling of the seismic wave field can be afforded, which in turn allows us to efficiently and adequately sample P-wave as well as S-wave for high-resolution imaging purposes. Design, packaging and integration of the multi-component sensors and deployment system will target maximum operating temperature of 350-400 F and a maximum pressure of 15000-25000 psi, thus allowing operation under conditions encountered in deep gas reservoirs. This project aimed at using existing pieces of deployment technology as well as MEMS and fiber-optic technology. A sensor design and analysis study has been carried out and a laboratory prototype of an interrogator for a robust borehole seismic array system has been assembled and validated.

  3. Quantitative elastic migration. Applications to 3D borehole seismic surveys; Migration elastique quantitative. Applications a la sismique de puits 3D

    Clochard, V.

    1998-12-02

    3D VSP imaging is nowadays a strategic requirement by petroleum companies. It is used to precise in details the geology close to the well. Because of the lack of redundancy and limited coverage in the data. this kind of technology is more restrictive than surface seismic which allows an investigation at a higher scale. Our contribution was to develop an elastic quantitative imagine (GRT migration) which can be applied to 3 components borehole dataset. The method is similar to the Kirchhoff migration using sophistical weighting of the seismic amplitudes. In reality. GRT migration uses pre-calculated Green functions (travel time. amplitude. polarization). The maps are obtained by 3D ray tracing (wavefront construction) in the velocity model. The migration algorithm works with elementary and independent tasks. which is useful to process different kind of dataset (fixed or moving geophone antenna). The study has been followed with validations using asymptotic analytical solution. The ability of reconstruction in 3D borehole survey has been tested in the Overthrust synthetic model. The application to a real circular 3D VSP shows various problems like velocity model building, anisotropy factor and the preprocessing (deconvolution. wave mode separation) which can destroy seismic amplitudes. An isotropic 3 components preprocessing of the whole dataset allows a better lateral reconstruction. The choice of a big migration aperture can help the reconstruction of strong geological dip in spite of migration smiles. Finally, the methodology can be applied to PS converted waves. (author)

  4. Development of a 400 Level 3C Clamped Downhole Seismic Receiver Array for 3D Borehole Seismic Imaging of Gas Reservoirs

    Bjorn N. P. Paulsson

    2006-09-30

    Borehole seismology is the highest resolution geophysical imaging technique available today to the oil and gas industry for characterization and monitoring of oil and gas reservoirs. However, the industry's ability to perform high resolution 3D imaging of deep and complex gas reservoirs using borehole seismology has been hampered by the lack of acquisition technology necessary to record large volumes of high frequency, high signal-to-noise-ratio borehole seismic data. This project took aim at this shortcoming by developing a 400 level 3C clamped downhole seismic receiver array, and accompanying software, for borehole seismic 3D imaging. This large borehole seismic array has removed the technical acquisition barrier for recording the data volumes necessary to do high resolution 3D VSP and 3D cross-well seismic imaging. Massive 3D VSP{reg_sign} and long range Cross-Well Seismology (CWS) are two of the borehole seismic techniques that promise to take the gas industry to the next level in their quest for higher resolution images of deep and complex oil and gas reservoirs. Today only a fraction of the oil or gas in place is produced when reservoirs are considered depleted. This is primarily due to our lack of understanding of detailed compartmentalization of oil and gas reservoirs. In this project, we developed a 400 level 3C borehole seismic receiver array that allows for economic use of 3D borehole seismic imaging for reservoir characterization and monitoring. This new array has significantly increased the efficiency of recording large data volumes at sufficiently dense spatial sampling to resolve reservoir complexities. The receiver pods have been fabricated and tested to withstand high temperature (200 C/400 F) and high pressure (25,000 psi), so that they can operate in wells up to 7,620 meters (25,000 feet) deep. The receiver array is deployed on standard production or drill tubing. In combination with 3C surface seismic or 3C borehole seismic sources, the 400

  5. Borehole seismic modeling

    Zhen, Tao

    In many borehole seismic experiments, the velocity of the tube wave is higher than that of the surrounding rock shear wave. This fast tube wave creates a strong conical shear wave in the surrounding rock, similar to the Mach wave in supersonic aviation and the Cherenkov radiation in electrodynamics. Many geophysicists have tried to utilize the conical signal in VSP (vertical seismic profiling) and cross borehole data interpretation, using quasi static approximations to model the borehole effect. Two popular quasi static approximations are: the effective source array method for source borehole modeling and the squeeze strain method for receiver borehole modeling. These quasi static approximations are sensible as they qualitatively conform to Hueygen's principle and the typical wavelength of a VSP or a cross borehole seismic experiment is much larger than the borehole radius. However, they have not been quantitatively benchmarked against other non approximation method such as the frequency wave number method. The frequency wave number method is a rigorous, non approximation method for modeling straight boreholes without lengthwise variation. The boreholes may consist of many coaxial, homogeneous and axially symmetric shells. In this thesis, the results of the quasi static approximations are compared to the results obtained from the frequency wave number method. The comparison demonstrates that both the effective source array method and squeeze strain method gives the correct arrival time. The effective source array method gives incorrect amplitude and waveform for direct arrivals and tube waves due to its arbitrary assumption of the elementary source radiation pattern. The squeeze strain method gives fairly accurate amplitude and waveform for P and S direct arrivals but it fails to match the tube wave results obtained from the frequency wave number method. The omission of tube wave dispersion and amplitude loss by the quasi static approximation methods also

  6. Determination of porosity and facies trends in a complex carbonate reservoir, by using 3-D seismic, borehole tools, and outcrop geology

    Zacharakis, T.G. Jr.; Comet, J.N.; Murillo, A.A. [Respol Exploracion, S.A., Madrid (Spain)] [and others

    1996-08-01

    Mesozoic carbonate reservoirs are found in the Mediterranean Sea, off the east coast of Spain. A wide variation of porosities are found in the core samples and logs: vuggy, breccia, fractures, and cavern porosity. In addition, complex Tertiary carbonate geometries include olistostromes, breccia bodies, and reef buildups, which are found on top of Mesozoic carbonates. Predicting the porosity trends within these oil productive reservoirs requires an understanding of how primary porosity was further enhanced by secondary processes, including fractures, karstification, and dolomitization in burial conditions. Through an extensive investigation of field histories, outcrop geology, and seismic data, a series of basic reservoir styles have been identified and characterized by well log signature and seismic response. The distribution pattern of the different reservoirs styles is highly heterogeneous, but by integrating subsurface data and outcrop analogs, it is possible to distinguish field-scale and local patterns of both vertical and local variations in reservoir properties. Finally, it is important to quantify these reservoir properties through the study of seismic attributes, such as amplitude variations, and log responses at the reservoir interval. By incorporating 3-D seismic data, through the use of seismic inversion, it is possible to predict porosity trends. Further, the use of geostatistics can lead to the prediction of reservoir development within the carbonate facies.

  7. Site response assessment using borehole seismic records

    Park, Donghee; Chang, Chunjoong; Choi, Weonhack [KHNP Central Research Institute, Daejeon (Korea, Republic of)

    2014-05-15

    In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. The Korea Meteorological Administration (KMA) and the Korea Institute of Geology and Mining (KIGAM) have installed and are operating borehole seismometers at a depth of 70∼100 meters for the precise determination of epicenters. Also, Korea Hydro and Nuclear Power Co., Ltd. (KHNP) has installed and is operating 2 borehole seismic stations near Weolseong area to observe at a depth of 140 meters seismic activities connected to fault activity. KHNP plans to operate in the second half of 2014 a borehole seismic station for depths less than 300 and 600 meters in order to study the seismic response characteristics in deep strata. As a basic study for analyzing ground motion response characteristics at depths of about 300 to 600 meters in connection with the deep geological disposal of spent nuclear fuel, the present study examined the background noise response characteristics of the borehole seismic station operated by KHNP. In order to analyze the depth-dependent impact of seismic waves at deeper depths than in Korea, seismic data collected by Japan's KIK-net seismic stations were used and the seismic wave characteristics analyzed by size and depth. In order to analyze the borehole seismic observation data from the seismic station operated by KHNP, this study analyzed the background noise characteristics by using a probability density function.

  8. Surface 3-D reflection seismics - implementation at the Olkiluoto site

    as weak scatterers. Svensk Kaernbraenslehantering Ab (SKB) has conducted 2-D seismic surveys at Oskarshamn and Forsmark investigation areas in Sweden and a 3-D seismic test on Aevroe island at Oskarshamn. Both dynamite and mechanical VIBSIST has been used as wave sources. Report describes measurement procedures and some results gained. Promising results correlated to borehole logging were also obtained in Aevroe 3-D test although the fold was low (about 12). A moving source-receiver, Pulled Array Seismic (PAS), system tested at Oskarshamn did not prove useful. Report contains also results from two ore body targeted 3D surveys. For Olkiluoto the study evaluates a few subareas for 3-D seismic test survey. The objective is to map continuity of gently dipping reflectors, variations in their locations and possible dislocations. One surveying configuration with adequate coverage, accuracy and detectability over more than 500 x 500 m area is discussed. Surveys over discrete subareas should be tied together if carried out separately. Imaging of steeply dipping reflectors require long source-receiver offsets or detection of time delays. (orig.)

  9. ONKALO 3D tunnel seismic investigations, Olkiluoto 2013

    Enescu, N.; Cosma, C.; Crawford, J. [Vibrometric Oy Cosma, Perttula (Finland)

    2014-10-15

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The purpose of these efforts, which include a significant R and D component, is to ensure compliance with the requirements set forth for the long-term safety of final disposal. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out in ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Deformation zones and hydraulically conductive zones can limit the areas which are suitable for a deposition hole to be placed. The main objective of the tunnel seismic investigations presented here is to develop a seismic investigation technique for deposition area characterization. The field work consisted of 3 receiver lines using 3-component geophones and sources locations using the Vibsist-500 for 6 profiles, the Vibsist-20 for 1 profile (sparse), and a mechanical borehole hammer, MH-70, for 5 profiles for a total of 12 profiles. This investigation took place in the ONKALO demonstration area. Design of the seismic field work is based on previous tunnel seismic works in ONKALO (Cosma et al. 2008 and 2011) and pre-survey numerical modeling for field data and processing (Heinonen et al. 2013). The fieldwork was carried out in June 2013. Tomographic inversion of P-wave first arrival times was done on combined data sets, containing data from several shot-receiver configurations along tunnels and boreholes. The velocity distributions derived by tomographic inversion were verified by comparison with the forward modeled profiles. The Image Point (IP) migration method is characterized by is its ability to accumulate reflection events measured in the time distance data sets into points in the IP domain, which permits the enhancement of coherent backscattered events. The result of the 3D IP migration

  10. ONKALO 3D tunnel seismic investigations, Olkiluoto 2013

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The purpose of these efforts, which include a significant R and D component, is to ensure compliance with the requirements set forth for the long-term safety of final disposal. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out in ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Deformation zones and hydraulically conductive zones can limit the areas which are suitable for a deposition hole to be placed. The main objective of the tunnel seismic investigations presented here is to develop a seismic investigation technique for deposition area characterization. The field work consisted of 3 receiver lines using 3-component geophones and sources locations using the Vibsist-500 for 6 profiles, the Vibsist-20 for 1 profile (sparse), and a mechanical borehole hammer, MH-70, for 5 profiles for a total of 12 profiles. This investigation took place in the ONKALO demonstration area. Design of the seismic field work is based on previous tunnel seismic works in ONKALO (Cosma et al. 2008 and 2011) and pre-survey numerical modeling for field data and processing (Heinonen et al. 2013). The fieldwork was carried out in June 2013. Tomographic inversion of P-wave first arrival times was done on combined data sets, containing data from several shot-receiver configurations along tunnels and boreholes. The velocity distributions derived by tomographic inversion were verified by comparison with the forward modeled profiles. The Image Point (IP) migration method is characterized by is its ability to accumulate reflection events measured in the time distance data sets into points in the IP domain, which permits the enhancement of coherent backscattered events. The result of the 3D IP migration

  11. Large-scale 3-D modeling by integration of resistivity models and borehole data through inversion

    Foged, N.; Marker, Pernille Aabye; Christiansen, A. V.;

    2014-01-01

    We present an automatic method for parameterization of a 3-D model of the subsurface, integrating lithological information from boreholes with resistivity models through an inverse optimization, with the objective of further detailing of geological models, or as direct input into groundwater models...... and the borehole data set in one variable. Finally, we use k-means clustering to generate a 3-D model of the subsurface structures. We apply the procedure to the Norsminde survey in Denmark, integrating approximately 700 boreholes and more than 100 000 resistivity models from an airborne survey in the...

  12. A combined surface and borehole seismic survey at the COSC-1 borehole

    Simon, Helge; Krauß, Felix; Hedin, Peter; Buske, Stefan; Giese, Rüdiger; Juhlin, Christopher

    2015-04-01

    The ICDP project COSC (Collisional Orogeny in the Scandinavian Caledonides) focuses on the mid Paleozoic Caledonide Orogen in Scandinavia in order to better understand orogenic processes, from the past and in recent active mountain belts. The Scandinavian Caledonides provide a well preserved example of a Paleozoic continent-continent collision. Surface geology in combination with geophysical data provide control of the geometry of the Caledonian structure, including the allochthon and the underlying autochthon, as well as the shallow W-dipping décollement surface that separates the two and consist of a thin skin of Cambrian black shales. During spring/summer 2014 the COSC-1 borehole was drilled to approx. 2.5 km depth near the town of Åre (western Jämtland/Sweden) with nearly 100 % of core recovery and cores in best quality. After the drilling was finished, a major seismic survey was conducted in and around the COSC-1 borehole which comprised both seismic reflection and transmission experiments. Besides a high resolution zero-offset VSP (Vertical Seismic Profiling) experiment also a multi-azimuthal walkaway VSP survey took place. For the latter the source points were distributed along three profile lines centered radially around the borehole. For the central part up to 2.5 km away from the borehole, a hydraulic hammer source was used, which hits the ground for about 20 s with an linear increasing hit rate. For the far offset shots up to 5 km, explosive sources were used. The wavefield of both source types was recorded in the borehole using an array of 15 three-component receivers with a geophone spacing of 10 m. This array was deployed at 7 different depth levels during the survey. At the same time the wavefield was also recorded at the surface by 180 standalone three-component receivers placed along each of the three up to 10 km long lines, as well as with a 3D array of single-component receivers in the central part of the survey area around the borehole. Here

  13. Development of a hydraulic borehole seismic source

    Cutler, R.P.

    1998-04-01

    This report describes a 5 year, $10 million Sandia/Industry project to develop an advanced borehole seismic source for use in oil and gas exploration and production. The development Team included Sandia, Chevron, Amoco, Conoco, Exxon, Raytheon, Pelton, and GRI. The seismic source that was developed is a vertically oriented, axial point force, swept frequency, clamped, reaction-mass vibrator design. It was based on an early Chevron prototype, but the new tool incorporates a number of improvements which make it far superior to the original prototype. The system consists of surface control electronics, a special heavy duty fiber optic wireline and draw works, a cablehead, hydraulic motor/pump module, electronics module, clamp, and axial vibrator module. The tool has a peak output of 7,000 lbs force and a useful frequency range of 5 to 800 Hz. It can operate in fluid filled wells with 5.5-inch or larger casing to depths of 20,000 ft and operating temperatures of 170 C. The tool includes fiber optic telemetry, force and phase control, provisions to add seismic receiver arrays below the source for single well imaging, and provisions for adding other vibrator modules to the tool in the future. The project yielded four important deliverables: a complete advanced borehole seismic source system with all associated field equipment; field demonstration surveys funded by industry showing the utility of the system; industrial sources for all of the hardware; and a new service company set up by their industrial partner to provide commercial surveys.

  14. Borehole Summary Report for Waste Treatment Plant Seismic Borehole C4993

    Rust, Colleen F.; Barnett, D. BRENT; Bowles, Nathan A.; Horner, Jake A.

    2007-02-28

    A core hole (C4998) and three boreholes (C4993, C4996, and C4997) were drilled to acquire stratigraphic and downhole seismic data to model potential seismic impacts and to refine design specifications and seismic criteria for the Waste Treatment Plant (WTP) under construction on the Hanford Site. Borehole C4993 was completed through the Saddle Mountains Basalt, the upper portion of the Wanapum Basalt, and associated sedimentary interbeds, to provide a continuous record of the rock penetrated by all four holes and to provide access to the subsurface for geophysical measure¬ment. Presented and compiled in this report are field-generated records for the deep mud rotary borehole C4993 at the WTP site. Material for C4993 includes borehole logs, lithologic summary, and record of rock chip samples collected during drilling through the months of August through early October. The borehole summary report also includes documentation of the mud rotary drilling, borehole logging, and sample collection.

  15. Borehole Summary Report for Waste Treatment Plant Seismic Borehole C4996

    Adams , S. C.; Ahlquist, Stephen T.; Fetters, Jeffree R.; Garcia, Ben; Rust, Colleen F.

    2007-01-28

    This report presents the field-generated borehole log, lithologic summary, and the record of samples collected during the recent drilling and sampling of the basalt interval of borehole C4996 at the Waste Treatment Plant (WTP) on the Hanford Site. Borehole C4996 was one of four exploratory borings, one core hole and three boreholes, drilled to investigate and acquire detailed stratigraphic and down-hole seismic data. This data will be used to define potential seismic impacts and refine design specifications for the Hanford Site WTP.

  16. Additional geological insight brought by 3-D seismic data

    Liu, Y.; Milton, J.

    2002-12-01

    3-D seismic data allows geo-scientists to study the earth at a level that is much more detailed than ever. It is shown in this case study that 3-D seismic can not only be used to identify different types of oil/gas reservoirs, significantly reduce the risk of misinterpretation, but also help to understand geological history and establish paleogeography at different geological times. In the study of Southeast Maricopa Seismic Survey in southern San Joaquin Valley, two types of potential hydrocarbon traps are interpreted: stratigraphical traps due to turbidite channels, and structural traps due to faulting. The distinctive characteristics of two types of channels indicate different depositional environments. With 3-D visualization tools, it is found that localized faults had been leaking during certain geological times, resulting in structural traps of oil/gas. A geological history of the local area can be estimated by building a series of pseudo-paleogeographic maps using 3-D seismic data, which further reconfirms the existence of different depositional systems indicated by two distinctive types of channels.

  17. Application of seismic attributes at the 3D seismic interpretation

    Bibiana Kytková

    2009-01-01

    Full Text Available This article brings a short overview of commonly used seismic attributes with their basic characterization. It also discusses the possibility of their application for the hydrocarbon prospection in two different areas. One of them is the Vienna Basin and the other one is the contact zone of the Bohemian Massif and the Western Carpathians (Vranovice and Nesvačilka Trough.

  18. Methods for use in detecting seismic waves in a borehole

    West, Phillip B.; Fincke, James R.; Reed, Teddy R.

    2007-02-20

    The invention provides methods and apparatus for detecting seismic waves propagating through a subterranean formation surrounding a borehole. In a first embodiment, a sensor module uses the rotation of bogey wheels to extend and retract a sensor package for selective contact and magnetic coupling to casing lining the borehole. In a second embodiment, a sensor module is magnetically coupled to the casing wall during its travel and dragged therealong while maintaining contact therewith. In a third embodiment, a sensor module is interfaced with the borehole environment to detect seismic waves using coupling through liquid in the borehole. Two or more of the above embodiments may be combined within a single sensor array to provide a resulting seismic survey combining the optimum of the outputs of each embodiment into a single data set.

  19. The business impact and value of 3-D seismic

    3-D Seismic has had a profound and lasting impact on the hydrocarbon exploration and production industry. It is a technology which is often excellent at assessing the risk associated with trap definition, seal and reservoir distribution, the very parameters which are the most critical to optimizing the economics associated with E and P projects. This paper discusses Amoco Corporation's experience with 3-D Seismic when used for new field rate acceleration, older field extension, and wildcat exploration. Its emphasis is on assessing the value added by 3-D by reviewing recent E and P experiences in a post-appraisal mode and then in applying the lessons learned from these analyses and case histories to potential new projects. This work is significant because it first assesses the impact 3-D has had on a large number of business situations at Amoco; that is, it is based on data collected on159 3-D surveys acquired at Amoco between 1991--1994. Second, it uses the data collected from these surveys and applies the business improvements observed in the data to typical international business opportunities to quantify, in expected value $ terms, the value that the technology brings to an average project. Finally, it looks at project economics not only from an oil company perspective, but from the standpoint of a host government, with a discussion of insights and implications of the data, economics and techniques utilized

  20. Advanced computational tools for 3-D seismic analysis

    Barhen, J.; Glover, C.W.; Protopopescu, V.A. [Oak Ridge National Lab., TN (United States)] [and others

    1996-06-01

    The global objective of this effort is to develop advanced computational tools for 3-D seismic analysis, and test the products using a model dataset developed under the joint aegis of the United States` Society of Exploration Geophysicists (SEG) and the European Association of Exploration Geophysicists (EAEG). The goal is to enhance the value to the oil industry of the SEG/EAEG modeling project, carried out with US Department of Energy (DOE) funding in FY` 93-95. The primary objective of the ORNL Center for Engineering Systems Advanced Research (CESAR) is to spearhead the computational innovations techniques that would enable a revolutionary advance in 3-D seismic analysis. The CESAR effort is carried out in collaboration with world-class domain experts from leading universities, and in close coordination with other national laboratories and oil industry partners.

  1. Response of 3D Free Rigid Objects under Seismic Excitations

    Yanheng, Li

    2008-01-01

    Previous studies of precariously balanced structures in seismically active regions to provide important information for aseismatic engineering and theoretical seismology are almost found on an oversimplified assumption. According to that, any 3-dimensional practical structure with special symmetry could be regarded as a 2-dimensional finite object in light of the corresponding symmetry. Thus the complex and troublesome problem of 3D rotation, in mathematics, can be reduced to a tractable one of 1D rotation but a distorted description of the real motion in physics. To gain an actual evolution of precariously balanced structures bearing various levels of ground accelerations, we should address ourselves to a 3D calculation. In this study, the responses of a cylinder under a set of half- and full-sine-wave excitations with different frequencies related to seismic ground motion are investigated in virtue of some reasonable works from a number of mechanicians. A computer program is also developed possibly to study...

  2. NORTH HILL CREEK 3-D SEISMIC EXPLORATION PROJECT

    Marc T. Eckels; David H. Suek; Denise H. Harrison; Paul J. Harrison

    2004-05-06

    Wind River Resources Corporation (WRRC) received a DOE grant in support of its proposal to acquire, process and interpret fifteen square miles of high-quality 3-D seismic data on non-allotted trust lands of the Uintah and Ouray (Ute) Indian Reservation, northeastern Utah, in 2000. Subsequent to receiving notice that its proposal would be funded, WRRC was able to add ten square miles of adjacent state and federal mineral acreage underlying tribal surface lands by arrangement with the operator of the Flat Rock Field. The twenty-five square mile 3-D seismic survey was conducted during the fall of 2000. The data were processed through the winter of 2000-2001, and initial interpretation took place during the spring of 2001. The initial interpretation identified multiple attractive drilling prospects, two of which were staked and permitted during the summer of 2001. The two initial wells were drilled in September and October of 2001. A deeper test was drilled in June of 2002. Subsequently a ten-well deep drilling evaluation program was conducted from October of 2002 through March 2004. The present report discusses the background of the project; design and execution of the 3-D seismic survey; processing and interpretation of the data; and drilling, completion and production results of a sample of the wells drilled on the basis of the interpreted survey. Fifteen wells have been drilled to test targets identified on the North Hill Creek 3-D Seismic Survey. None of these wildcat exploratory wells has been a dry hole, and several are among the best gas producers in Utah. The quality of the data produced by this first significant exploratory 3-D survey in the Uinta Basin has encouraged other operators to employ this technology. At least two additional 3-D seismic surveys have been completed in the vicinity of the North Hill Creek Survey, and five additional surveys are being planned for the 2004 field season. This project was successful in finding commercial oil, natural gas

  3. Full 3-D numerical modeling of borehole electric image logging and the evaluation model of fracture

    2008-01-01

    A full 3-D finite element method numerical modeling program is written based on the principle and technical specification of borehole electric image well logging tool. The response of well logging is computed in the formation media model with a single fracture. The effect of changing fracture aperture and resistivity ratio to the logging response is discussed. The identification ability for two parallel fractures is also present. A quantitative evaluation formula of fracture aperture from borehole electric image logging data is set up. A case study of the model well is done to verify the accuracy of the for-mula. The result indicates that the formula is more accurate than the foreign one.

  4. 3D seismic data for shallow aquifers characterisation

    Giustiniani, Michela; Accaino, Flavio; Picotti, Stefano; Tinivella, Umberta

    2009-07-01

    We present the results obtained from conventional and non-conventional analysis of 3D high-resolution seismic data acquired nearby the water spring line, which separates the upper from the lower Friuli-Venezia Giulia plain (Italy), in order to characterise an important multilayered confined aquifer. The main targets of this study were two shallow aquifers located at about 30 m and 180 m depth, respectively. The aquifer structures were reconstructed by adopting a technique consisting an iterative updating procedure, for refining and improving an initial model in depth. The method includes pre-stack depth migration, residual move-out analysis and seismic reflection tomography. In the final 3D migrated cubes, two high velocity layers were identified at about 270 m and 480 m respectively, which correspond to unknown deep aquifers, as confirmed by recent well data (stratigraphies and down-hole velocity measurements). Travel-time tomography and Amplitude Versus Offset analysis evidence that seasonal variation in the seismic response of the aquifers are not detectable. However, in this case, aquifers are well detectable by lithological changes.

  5. ONKALO 3D tunnel seismic investigations at Olkiluoto in 2009

    Cosma, C.; Enescu, N.; Balu, L.; Jacome, M. (Vibrometric Oy, Perttuola (Finland))

    2011-02-15

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out at ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Tunnel seismic investigations were carried out in July 2009, as an extension of similar work performed in December 2007. The main objective of the tunnel seismic investigations have been to demonstrate the possibility to detect, locate and image cost effectively steeply and gently dipping fractures, at the side and/or below the tunnel and to characterize the volume of rock surrounding a 250 m long segment of the ONKALO tunnel. The survey was conducted at a depth of 350 m, over a 240 m long line of 3-components receivers, spaced at 3m intervals. Seismic signals were produced along two lines, on the tunnel wall and floor, with source points spaced at 1m. A timedistributed swept-impact, the Vibsist-250 hydraulic source, was used. The source was hosted on a mini excavator. Receiver holes approximately 0.4 m deep were drilled prior to the survey, horizontally into the tunnel wall. One of the procedures used for data stacking and migration is based on a proprietary method combining the DMO (Dip Move Out) correction and an expression of the Radon Transform. Horizontal and vertical migrated profiles were computed both for the P wave and S wave reflected wave fields. A true 3D migration technique (Image Point migration) was used to create 3D migrated sections oriented to incremental azimuths around the tunnel, the result being a cylindrical imaging volume. A general conclusion is that seismic surveys along the tunnel can economically be used for rock mass characterization. High quality results can be obtained by operations in tunnel working conditions, provided that due

  6. ONKALO 3D tunnel seismic investigations at Olkiluoto in 2009

    POSIVA Oy conducts bedrock investigations at the spent nuclear fuel final disposal site at Olkiluoto, in western Finland. The excavation of the access tunnel to the repository hosts the ONKALO underground rock characterization facility. The investigations carried out at ONKALO focus on the bedrock and groundwater conditions prevailing on the final disposal site and how construction work affects them. Tunnel seismic investigations were carried out in July 2009, as an extension of similar work performed in December 2007. The main objective of the tunnel seismic investigations have been to demonstrate the possibility to detect, locate and image cost effectively steeply and gently dipping fractures, at the side and/or below the tunnel and to characterize the volume of rock surrounding a 250 m long segment of the ONKALO tunnel. The survey was conducted at a depth of 350 m, over a 240 m long line of 3-components receivers, spaced at 3m intervals. Seismic signals were produced along two lines, on the tunnel wall and floor, with source points spaced at 1m. A timedistributed swept-impact, the Vibsist-250 hydraulic source, was used. The source was hosted on a mini excavator. Receiver holes approximately 0.4 m deep were drilled prior to the survey, horizontally into the tunnel wall. One of the procedures used for data stacking and migration is based on a proprietary method combining the DMO (Dip Move Out) correction and an expression of the Radon Transform. Horizontal and vertical migrated profiles were computed both for the P wave and S wave reflected wave fields. A true 3D migration technique (Image Point migration) was used to create 3D migrated sections oriented to incremental azimuths around the tunnel, the result being a cylindrical imaging volume. A general conclusion is that seismic surveys along the tunnel can economically be used for rock mass characterization. High quality results can be obtained by operations in tunnel working conditions, provided that due

  7. 3D Geotechnical Soil Model of Nice, France, Inferred from Seismic Noise Measurements, for Seismic Hazard Assessment.

    Bertrand, E.; Duval, A.; Castan, M.; Vidal, S.

    2007-12-01

    In seismic risk studies, the assessment of lithologic site effect is based on an accurate knowledge of mechanical properties and geometry of superficial geological formations. Therefore, we built a 3D subsurface model in the city of Nice, southeastern France, using not only geological and geotechnical data but also geophysical inputs. We used especially ambient vibration recordings to supply the lack of borehole data over the city. Nice spreads over 72 km2 and roughly 20% of the city is built upon recent alluvium deposits. Other parts of the city lie on Jurassic and Cretaceous rocks to the east and thick Pliocene conglomerates to the west. Nearly 450 boreholes located mainly in the alluvial valleys were used. Because they are essentially linked to previous planned constructions (such as road network or important building), their distribution is rather heterogeneous over the studied area. In the valleys moreover, less than 40% of the boreholes are reaching the rock basement. These boreholes have been analyzed and a representative soil column made of 9 sedimentary layers has been recognized. Shear wave velocity of these layers were obtained from Standard Penetration Test values using several empirical correlation law described in the literature. Because of its cost, an extended boring survey was not feasible to complete our data set. Traditional seismic profiling was also not intended, as it is not possible to use intensive explosive sources in town. Recent years have seen many studies using ambient vibration measurements for site effect estimation. Especially, the very simple H/V technique was proven to be suitable for microzoning studies although some limitation were pointed out when dealing with 2D or 3D structures. Nevertheless, this technique alone provides only the fundamental eigenfrequency of the site under investigation. But assuming the shear wave velocity in the sediment it can helps to constrain the depth of the bedrock thanks to the well known f0=VS/4H

  8. 3-D structure below Aevroe Island from high-resolution reflection seismic studies, southeastern Sweden

    Reflection seismology has served as a useful tool for imaging and mapping of fracture zones in crystalline rock along 2-D lines in nuclear waste disposal studies. Two 1-km-long perpendicular seismic reflection lines were acquired on Aevroe Island, southeast Sweden, in October 1996 in order to (1) test the seismic reflection method for future site investigations, (2) map known fracture zones, and (3) add to the Swedish database of reflection seismic studies of the shallow crystalline crust. An east-west line was shot with 5-m geophone and shot-point spacing, and a north-south line was shot with 10-m geophone and shotpoint spacing. An explosive source with a charge size of 100 g was used along both lines. The data clearly image three major dipping reflectors and one subhorizontal one in the upper 200 ms (600 m). The dipping reflectors (to the south, east, and northwest) intersect or project to the surface at or close to where surface-mapped fracture zones exist. The south-dipping reflector correlates with the top of a heavily fractured interval observed in a borehole (KAV01) at about 400 m. The subhorizontal zone at about 100--200 m correlates with a known fracture zone in the same borehole (KAV01). 3-D effects are apparent in the data, and only where the profiles cross can the true orientation of the reflecting events be determined. To properly orient and locate all events observed on the lines requires acquisition of 3-D data

  9. Exploring the seismic expression of fault zones in 3D seismic volumes

    Iacopini, D.; Butler, R. W. H.; Purves, S.; McArdle, N.; De Freslon, N.

    2016-08-01

    Mapping and understanding distributed deformation is a major challenge for the structural interpretation of seismic data. However, volumes of seismic signal disturbance with low signal/noise ratio are systematically observed within 3D seismic datasets around fault systems. These seismic disturbance zones (SDZ) are commonly characterized by complex perturbations of the signal and occur at the sub-seismic (10 s m) to seismic scale (100 s m). They may store important information on deformation distributed around those larger scale structures that may be readily interpreted in conventional amplitude displays of seismic data. We introduce a method to detect fault-related disturbance zones and to discriminate between this and other noise sources such as those associated with the seismic acquisition (footprint noise). Two case studies from the Taranaki basin and deep-water Niger delta are presented. These resolve SDZs using tensor and semblance attributes along with conventional seismic mapping. The tensor attribute is more efficient in tracking volumes containing structural displacements while structurally-oriented semblance coherency is commonly disturbed by small waveform variations around the fault throw. We propose a workflow to map and cross-plot seismic waveform signal properties extracted from the seismic disturbance zone as a tool to investigate the seismic signature and explore seismic facies of a SDZ.

  10. Optical instruments for a combined seismic and geodetic borehole observatory

    Zumberge, Mark; Agnew, Duncan; Berger, Jonathan; Hatfield, William; Wyatt, Frank

    2016-04-01

    Optical interferometry offers displacement sensing with the unusual combination of high sensitivity, linearity, and wide dynamic range, and it can be adapted to high temperature environments. We have applied interferometric technology to inertial seismic instruments and to optical fibers for strain measurements. When combining these methods into a single borehole package the result is a system that provides three components of observatory quality seismic recordings, two components of tilt, gravity, and vertical strain. The borehole package is entirely passive with the need for only optical fibers to connect the sensor sonde with surface electronics. One of the sensors in the system is an optical fiber strainmeter, which consists of an optical fiber cable elastically stretched between two borehole anchor points separated by 100 m or more. The fiber's length is recorded optically, enabling sub-nanostrain detection of crustal deformations. A second sensor system uses laser interferometry to record the displacements of inertial mechanical suspensions - spring-mass for the vertical component and pendulums for the horizontal components - housed in a borehole sonde. The combined system is able to measure vertical and horizontal ground velocities, gravity, and tilt with sensitivities that compare favorably with any existing borehole system over time scales from 10 Hz to many days; because the downhole components are entirely passive, the instrument will have a long lifetime and could be made usable at high downhole temperatures. The simplicity and longevity of the metal and glass borehole sonde make it suitable for permanent cementation into a borehole to achieve good coupling and stability. Several versions of the borehole inertial system have been deployed on land with excellent results, and a number of our optical fiber strainmeters have been deployed - both onshore and offshore. The combined system is currently under development.

  11. 3D, 9-C anisotropic seismic modeling and inversion

    Rusmanugroho, Herurisa

    The most complete representation of an elastic medium consists of an elastic tensor with 21 independent moduli. All 21 can be estimated from compressional and shear wave polarization and slowness vectors corresponding to wide apertures of polar and azimuth angles. In isotropic media, when seismic source and receiver components have the same orientation (such as XX and YY), the reflection amplitude contours align approximately perpendicular to the particle motions. The mixed components (such as XY and YX) have amplitude patterns that are in symmetrical pairs of either the same, or of opposite, polarity on either side of the diagonal of the 9-C response matrix. In anisotropic media, amplitude variations with azimuth show the same basic patterns and symmetries as for isotropic, but with a superimposed tendency for alignment parallel to the strike of the vertical cracks. Solutions for elastic tensor elements from synthetic slowness and polarization data calculated directly from the Christoffel equation are more sensitive to the polar angle aperture than to the azimuth aperture. Nine-component synthetic elastic vertical seismic profile data for a model with triclinic symmetry calculated by finite-differencing allows estimation of the elastic 21 tensor elements in the vicinity of a three-component borehole receiver. Wide polar angle and azimuth apertures are needed for accurately estimating the elastic tensor elements. The tensor elements become less independent as the data apertures decrease. Results obtained by extracting slowness and polarization data from the corresponding synthetic seismograms show similar results. The inversion algorithm has produced good results from field vertical seismic profile data set from the Weyburn Field in Southern Saskatchewan in Canada. Synthetic nine-component seismograms calculated from the extracted tensor are able to explain most of the significant features in the field data. The inverted stiffness elastic tensor shows orthorhombic

  12. DMO processing on the Ketzin 3D seismic data

    Huang, Fei; Juhlin, Christopher; Ivandic, Monika; Zhang, Fengjiao

    2014-05-01

    The Dip-moveout (DMO) correction is a process which attempts to make the finite offset data closer to zero offset data after the normal-moveout (NMO) correction. The NMO correction is then dip independent and reflections with different dips will stack coherently. DMO plays a critical role in seismic processing by enhancing the final image quality of the seismic data. In this study, we apply 3D Squeezing DMO (Hale and Artley, 1993) to seismic data from the Ketzin pilot CO2 site after NMO to study the impact of DMO on time-lapse seismic imaging and to investigate if it enhances the CO2 seismic monitoring technique. This 3D DMO method is based on an integral approach and incorporates Hale and Artley's (1993) modifications for variable velocity with time. A constant velocity algorithm is used with a gamma correction function which depends on the velocity function. An anti-alias velocity of 3000 m/s is used for the DMO. After DMO the data are stacked and F-XY deconvolution is applied. Finally, 3D finite-difference migration using the final smoothed NMO velocities is performed for each data set. We then apply a time-lapse analysis to the 3D seismic data sets and compare the results with and without DMO processing. The most important aspect of the DMO processing is determining the velocity field for the NMO step. This is done by using the initial smoothed velocity field obtained from the conventional velocity analysis before DMO as a first estimate. The data are input into the DMO process and then inverse NMO is applied. These data are then subjected to a new velocity analysis and the velocity field is updated and used as input for the NMO process. A number of iterations are generally required until the velocity field does not need further updating. In this study velocities were picked at every 20th CDP in the inline and crossline directions. Compared to the velocity spectrum without DMO processing, the velocity trend is improved and the ambiguity in the velocity picks is

  13. Geology of the Waste Treatment Plant Seismic Boreholes

    Barnett, D. BRENT; Bjornstad, Bruce N.; Fecht, Karl R.; Lanigan, David C.; Reidel, Steve; Rust, Colleen F.

    2007-02-28

    In 2006, DOE-ORP initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct Vs measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) confirmation of the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the corehole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt was also penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of movement and less than 15 feet of repeated section. Most of the

  14. 3D Seismic Investigations at Olkiluoto 2007 Factual Report

    Cosma, C.; Cozma, M.; Enescu, N. (Vibrometric Oy, Vantaa (Finland))

    2008-08-15

    This document describes the activities related to 3D seismic investigations done at Olkiluoto, Finland, in 2007. The investigations were done in order to infer the position and to assess the continuity of gently dipping features in an area at the South West of the 3D survey acquired in 2006. The receiver template neither extends over the ONKALO area, nor is it adjacent to the 3D patch acquired during 2006. Site preparation, mobilisation, data acquisition and demobilisation have been done from April 15th until June 10th. 581 shots have been recorded by 240 channels. The area of investigations is centered on East = 1526530, North = 6791770. Posiva performed staking, according to the survey plans designed by Vibrometric. True coordinates were measured with +/-0.5 m accuracy for all stations. The source used was a VIBSIST-1000 mounted on a 24-tone Liebherr tracked excavator, with a Krupp HM 720-4000 hydraulic breaker. A Summit II Plus 24-bit seismic data recording system, with 186 channels and a Summit II system with 64 channels were used for data acquisition. The geophones used were 28 Hz OYO Geospace (SNG20DM/PC-710/KCL-4F/33'). The data have been processed in November 2007 by Vibrometric Oy and Uppsala University. The main processing platform has been Claritas 3D Seismic Processing Software. A thorough noise coherency analysis was performed, because of the relatively large number of raw shot gathers on which the arrival times could not be picked due to noise contamination. Electric, weather and cultural noise patterns were identified and removed. The data were binned into 8.33 m x 12.5 m CDP bins. Statics, both refraction and residual, and choice of temporal filter had the greatest influence on the processed stack. The stack was relatively insensitive to the velocity used. DMO helped somewhat in imaging dipping reflections. Data from the 3D cube has been migrated using Stolt and FD migration algorithms. There are three main zones of reflectivity, the first at

  15. 3D Seismic Investigations at Olkiluoto 2007 Factual Report

    This document describes the activities related to 3D seismic investigations done at Olkiluoto, Finland, in 2007. The investigations were done in order to infer the position and to assess the continuity of gently dipping features in an area at the South West of the 3D survey acquired in 2006. The receiver template neither extends over the ONKALO area, nor is it adjacent to the 3D patch acquired during 2006. Site preparation, mobilisation, data acquisition and demobilisation have been done from April 15th until June 10th. 581 shots have been recorded by 240 channels. The area of investigations is centered on East = 1526530, North = 6791770. Posiva performed staking, according to the survey plans designed by Vibrometric. True coordinates were measured with +/-0.5 m accuracy for all stations. The source used was a VIBSIST-1000 mounted on a 24-tone Liebherr tracked excavator, with a Krupp HM 720-4000 hydraulic breaker. A Summit II Plus 24-bit seismic data recording system, with 186 channels and a Summit II system with 64 channels were used for data acquisition. The geophones used were 28 Hz OYO Geospace (SNG20DM/PC-710/KCL-4F/33'). The data have been processed in November 2007 by Vibrometric Oy and Uppsala University. The main processing platform has been Claritas 3D Seismic Processing Software. A thorough noise coherency analysis was performed, because of the relatively large number of raw shot gathers on which the arrival times could not be picked due to noise contamination. Electric, weather and cultural noise patterns were identified and removed. The data were binned into 8.33 m x 12.5 m CDP bins. Statics, both refraction and residual, and choice of temporal filter had the greatest influence on the processed stack. The stack was relatively insensitive to the velocity used. DMO helped somewhat in imaging dipping reflections. Data from the 3D cube has been migrated using Stolt and FD migration algorithms. There are three main zones of reflectivity, the first at 300

  16. High-resolution 3D seismic model of the crustal and uppermost mantle structure in Poland

    Grad, Marek; Polkowski, Marcin; Ostaficzuk, Stanisław R.

    2016-01-01

    In the area of Poland a contact between the Precambrian and Phanerozoic Europe and the Carpathians has a complicated structure and a complex P-wave velocity of the sedimentary cover, crystalline crust, Moho depth and the uppermost mantle. The geometry of the uppermost several kilometers of sediments is relatively well recognized from over 100,000 boreholes. The vertical seismic profiling (VSP) from 1188 boreholes provided detailed velocity data for regional tectonic units and for stratigraphic successions from Permian to the Tertiary and Quaternary deposits. These data, however, do not provide information about the velocity and basement depth in the central part of the Trans-European suture zone (TESZ) and in the Carpathians. So, the data set is supplemented by 2D velocity models from 32 deep seismic sounding refraction profiles which also provide information about the crust and uppermost mantle. Together with the results of other methods: vertical seismic profiling, magnetotelluric, allow for the creation of a detailed, high-resolution 3D model for the entire Earth's crust and the uppermost mantle down to a depth of 60 km. The thinnest sedimentary cover in the Mazury-Belarus anteclise is only 0.3 to 1 km thick, which increases to 7 to 8 km along the East European Craton (EEC) margin, and 9 to 12 km in the TESZ. The Variscan domain is characterized by a 1-4 km thick sedimentary cover, while the Carpathians are characterized by very thick sedimentary layers, up to about 20 km. The crystalline crust is differentiated and has a layered structure. The crust beneath the West European Platform (WEP; Variscan domain) is characterized by P-wave velocities of 5.8-6.6 km/s. The upper and middle crusts beneath the EEC are characterized by velocities of 6.1-6.6 km/s, and are underlain by a high velocity lower crust with a velocity of about 7 km/s. A general decrease in velocity is observed from the older to the younger tectonic domains. The TESZ is associated with a steep dip

  17. Reversible rigid coupling apparatus and method for borehole seismic transducers

    Owen, Thomas E.; Parra, Jorge O.

    1992-01-01

    An apparatus and method of high resolution reverse vertical seismic profile (VSP) measurements is shown. By encapsulating the seismic detector and heaters in a meltable substance (such as wax), the seismic detector can be removably secured in a borehole in a manner capable of measuring high resolution signals in the 100 to 1000 hertz range and higher. The meltable substance is selected to match the overall density of the detector package with the underground formation, yet still have relatively low melting point and rigid enough to transmit vibrations to accelerometers in the seismic detector. To minimize voids in the meltable substance upon solidification, the meltable substance is selected for minimum shrinkage, yet still having the other desirable characteristics. Heaters are arranged in the meltable substance in such a manner to allow the lowermost portion of the meltable substance to cool and solidify first. Solidification continues upwards from bottom-to-top until the top of the meltable substance is solidified and the seismic detector is ready for use. To remove, the heaters melt the meltable substance and the detector package is pulled from the borehole.

  18. Seismic Wave Amplification in 3D Alluvial Basins: 3D/1D Amplification Ratios from Fast Multipole BEM Simulations

    Fajardo, Kristel C Meza; Chaillat, Stéphanie; Lenti, Luca

    2016-01-01

    In this work, we study seismic wave amplification in alluvial basins having 3D standard geometries through the Fast Multipole Boundary Element Method in the frequency domain. We investigate how much 3D amplification differs from the 1D (horizontal layering) case. Considering incident fields of plane harmonic waves, we examine the relationships between the amplification level and the most relevant physical parameters of the problem (impedance contrast, 3D aspect ratio, vertical and oblique incidence of plane waves). The FMBEM results show that the most important parameters for wave amplification are the impedance contrast and the so-called equivalent shape ratio. Using these two parameters, we derive simple rules to compute the fundamental frequency for various 3D basin shapes and the corresponding 3D/1D amplification factor for 5% damping. Effects on amplification due to 3D basin asymmetry are also studied and incorporated in the derived rules.

  19. Crosshole investigations - results from seismic borehole tomography

    The specially developed system for seismic tomography measurements has proved reliable and versatile in field work. The same equipment can be used for measurements from tens of metres up to a distance of 1000 m. The explosive source has proven reliable, in use although time-consuming. It can be used over the full range of distances. The quality of the tomographic analysis is strongly dependent on the areas under study. In homogeneous rock, and at moderate (i.e. up to 200 m) distances, high-precision tomograms can be obtained. On the other hand, if the rock is heterogeneous, and/or the measuring distance large, the many possible solutions make the interpretation difficult. Information from other types of investigations are then usually needed in order to obtain a satisfactory result. Three-dimensional measurements are possible, although time-consuming. (orig./DG)

  20. Borehole seismic in crystalline environment at the COSC-project in Central Sweden

    Krauß, Felix; Hedin, Peter; Almqvist, Bjarne; Simon, Helge; Giese, Rüdiger; Buske, Stefan; Juhlin, Christopher; Lorenz, Henning

    2016-04-01

    As support for the COSC drilling project (Collisional Orogeny in the Scandinavian Caledonides), an extensive seismic survey took place during September and October 2014 in and around the newly drilled 2.5 km deep COSC-1 borehole. The main aim of the COSC project is to better understand orogenic processes in past and recently active mountain belts. For this, the Scandinavian Caledonides provide a well preserved case of Paleozoic collision of the Laurentia and Baltica continental plates. Surface geology and geophysical data provide knowledge about the geometry of the Caledonian structure. The reflectivity geometry of the upper crust was imaged by regional seismic data and the resistivity structure by magnetotelluric methods. The crustal model was refined by seismic pre-site surveys in 2010 and 2011 to define the exact position of the first borehole, COSC-1. The completely cored COSC-1 borehole was drilled in Central Sweden through the Seve Nappe Complex, a part of the Middle Allochthon of the Scandinavian Caledonides that comprises units originating from the outer margin of Baltica. The upper 2350 m consist of alternating layers of highly strained felsic and calc-silicate gneisses and amphibolites. Below 1710 m the mylonite content increases successively and indicates a high strain zone of at least 800 m thickness. At ca. 2350 m, the borehole leaves the Seve Nappe Complex and enters underlying mylonitised lower grade metasedimentary units of unknown tectonostratigraphic position. The seismic survey consisted of three parts: a limited 3D-survey, a high resolution zero-offset VSP (vertical seismic profile) and a multi-azimuthal walkaway VSP (MSP) experiment with sources and receivers along three surface profiles and receivers at seven different depth levels of the borehole. For the zero-offset VSP (ZVSP) a hydraulic hammer source was used and activated over a period of 20 s as a sequence of impacts with increasing hit frequency. The wave field was recorded with 3

  1. Geology of the Waste Treatment Plant Seismic Boreholes

    Barnett, D. Brent; Fecht, Karl R.; Reidel, Stephen P.; Bjornstad, Bruce N.; Lanigan, David C.; Rust, Colleen F.

    2007-05-11

    In 2006, the U.S. Department of Energy initiated the Seismic Boreholes Project (SBP) to emplace boreholes at the Waste Treatment Plant (WTP) site in order to obtain direct shear wave velocity (Vs) measurements and other physical property measurements in Columbia River basalt and interbedded sediments of the Ellensburg Formation. The goal was to reduce the uncertainty in the response spectra and seismic design basis, and potentially recover design margin for the WTP. The characterization effort within the deep boreholes included 1) downhole measurements of the velocity properties of the suprabasalt, basalt, and sedimentary interbed sequences, 2) downhole measurements of the density of the subsurface basalt and sediments, and 3) geologic studies to confirm the geometry of the contact between the various basalt and interbedded sediments through examination of retrieved core from the core hole and data collected through geophysical logging of each borehole. This report describes the results of the geologic studies from three mud-rotary boreholes and one cored borehole at the WTP. All four boreholes penetrated the entire Saddle Mountains Basalt and the upper part of the Wanapum Basalt where thick sedimentary interbeds occur between the lava flows. The basalt flows penetrated in Saddle Mountains Basalt included the Umatilla Member, Esquatzel Member, Pomona Member, and the Elephant Mountain Member. The underlying Priest Rapids Member of the Wanapum Basalt also was penetrated. The Ellensburg Formation sediments consist of the Mabton Interbed, the Cold Creek Interbed, the Selah Interbed, and the Rattlesnake Ridge Interbed; the Byron Interbed occurs between two flows of the Priest Rapids Member. The Mabton Interbed marks the contact between the Wanapum and Saddle Mountains Basalts. The thicknesses of the basalts and interbedded sediments were within expected limits. However, a small reverse fault was found in the Pomona Member flow top. This fault has three periods of

  2. Q AS A LITHOLOGICAL/HYDROCARBON INDICATOR: FROM FULL WAVEFORM SONIC TO 3D SURFACE SEISMIC

    Jorge O. Parra; C.L. Hackert; L. Wilson; H.A. Collier; J. Todd Thomas

    2006-03-31

    The goal of this project was to develop a method to exploit viscoelastic rock and fluid properties to greatly enhance the sensitivity of surface seismic measurements to the presence of hydrocarbon saturation. To reach the objective, Southwest Research Institute scientists used well log, lithology, production, and 3D seismic data from an oil reservoir located on the Waggoner Ranch in north central Texas. The project was organized in three phases. In the first phase, we applied modeling techniques to investigate seismic- and acoustic-frequency wave attenuation and its effect on observable wave attributes. We also gathered existing data and acquired new data from the Waggoner Ranch field, so that all needed information was in place for the second phase. During the second phase, we developed methods to extract attenuation from borehole acoustic and surface seismic data. These methods were tested on synthetic data constructed from realistic models and real data. In the third and final phase of the project, we applied this technology to a full data set from the Waggoner site. The results presented in this Final Report show that geological conditions at the site did not allow us to obtain interpretable results from the Q processing algorithm for 3D seismic data. However, the Q-log processing algorithm was successfully applied to full waveform sonic data from the Waggoner site. A significant part of this project was technology transfer. We have published several papers and conducted presentations at professional conferences. In particular, we presented the Q-log algorithm and applications at the Society of Exploration Geophysicists (SEG) Development and Production Forum in Austin, Texas, in May 2005. The presentation attracted significant interest from the attendees and, at the request of the SEG delegates, it was placed on the Southwest Research Institute Internet site. The presentation can be obtained from the following link: http://www.swri.org/4org/d15/elecsys

  3. 3D seismic reverse time migration on GPGPU

    Liu, Guofeng; Liu, Yaning; Ren, Li; Meng, Xiaohong

    2013-09-01

    Reverse time migration (RTM) is a powerful seismic imaging method for the interpretation of steep-dips and subsalt regions; however, implementation of the RTM method is computationally expensive. In this paper, we present a fast and computationally inexpensive implementation of RTM using a NVIDIA general purpose graphic processing unit (GPGPU) powered with Compute Unified Device Architecture (CUDA). To accomplish this, we introduced a random velocity boundary in the source propagation kernel. By creating a random velocity layer at the left, right, and bottom boundaries, the wave fields that encounter the boundary regions are pseudo-randomized. Reflections off the random layers have minimal coherent correlation in the reverse direction. This process eliminates the need to write the wave fields to a disk, which is important when using a GPU because of the limited bandwidth of the PCI-E that is connected to the CPU and GPU. There are four GPU kernels in the code: shot, receiver, modeling, and imaging. The shot and receiver insertion kernels are simple and are computed using a GPU because the wave fields reside in GPU's memory. The modeling kernel is computed using Micikevicius's tiling method, which uses shared memory to improve bandwidth usage in 2D and 3D finite difference problems. In the imaging kernel, we also use this tiling method. A Tesla C2050 GPU with 4 GB memory and 480 stream processing units was used to test the code. The shot and receiver modeling kernel occupancy achieved 85%, and the imaging kernel occupancy was 100%. This means that the code achieved a good level of optimization. A salt model test verified the correct and effective implementation of the GPU RTM code.

  4. 3D Modelling of Seismically Active Parts of Underground Faults via Seismic Data Mining

    Frantzeskakis, Theofanis; Konstantaras, Anthony

    2015-04-01

    During the last few years rapid steps have been taken towards drilling for oil in the western Mediterranean sea. Since most of the countries in the region benefit mainly from tourism and considering that the Mediterranean is a closed sea only replenishing its water once every ninety years careful measures are being taken to ensure safe drilling. In that concept this research work attempts to derive a three dimensional model of the seismically active parts of the underlying underground faults in areas of petroleum interest. For that purpose seismic spatio-temporal clustering has been applied to seismic data to identify potential distinct seismic regions in the area of interest. Results have been coalesced with two dimensional maps of underground faults from past surveys and seismic epicentres, having followed careful reallocation processing, have been used to provide information regarding the vertical extent of multiple underground faults in the region of interest. The end product is a three dimensional map of the possible underground location and extent of the seismically active parts of underground faults. Indexing terms: underground faults modelling, seismic data mining, 3D visualisation, active seismic source mapping, seismic hazard evaluation, dangerous phenomena modelling Acknowledgment This research work is supported by the ESPA Operational Programme, Education and Life Long Learning, Students Practical Placement Initiative. References [1] Alves, T.M., Kokinou, E. and Zodiatis, G.: 'A three-step model to assess shoreline and offshore susceptibility to oil spills: The South Aegean (Crete) as an analogue for confined marine basins', Marine Pollution Bulletin, In Press, 2014 [2] Ciappa, A., Costabile, S.: 'Oil spill hazard assessment using a reverse trajectory method for the Egadi marine protected area (Central Mediterranean Sea)', Marine Pollution Bulletin, vol. 84 (1-2), pp. 44-55, 2014 [3] Ganas, A., Karastathis, V., Moshou, A., Valkaniotis, S., Mouzakiotis

  5. Subglacial Landforms and Processes: new Information From 3D Seismic Technology

    Andreassen, K.

    2007-12-01

    Three-dimensional (3D) seismic interpretation and imaging techniques provide a unique means of investigating submarine geomorphic features produced by former ice sheets. An extensive two-dimensional (2D) and 3D seismic data base is here used to image the imprints left behind by glaciers that flowed out a major cross-shelf trough (Bjornoyrenna) of the north-Norwegian continental shelf during repeated glacial episodes. Mega-scale glacial lineations characterize the seafloor geomorphology of Bjornoyrenna and smaller, contributing cross-shelf troughs, where they are inferred to represent flow-lines of former ice streams that where active during the most recent (Weichselian) glacial period. Similar features are commonly observed on buried horizons. Large- scale seafloor imprints from an early readvance after the last glacial maximum are especially well preserved. Streamlined landforms and associated lobe-shaped ridges indicate that this major cross-shelf trough hosted six separate ice stream lobes that diverged fan-like at their margins, but were not all active simultaneously. A 300 km wide grounding-zone wedge results from high sediment flux within sub-ice stream deformable beds. A 2 to 3 km thick Pleistocene record is preserved at the mouth of Bjornoyrenna, in the Bjornoya Trough Mouth Fan. The preservation of up to several hundred meters of glacigenic sediments between the buried, glacially eroded surfaces, provides here the opportunity to study the internal structure of till units. 3D seismic attribute maps reveal that megablocks and rafts commonly occur within the till units. The sediments blocks are often aligned in chains that may be up to 2 km wide and over 50 km long. The largest individual megablocks have an areal extent of over 2 km2. The sediment chains are interpreted to have been eroded, transported and deposited by grounded ice, most probably fast-flowing ice streams. This is based on the relationship between the sediment chains and the horizons revealing

  6. Fuzzy C-means Clustering for 3D Seismic Parameters Processing

    Fuqun Zhao; Liang Le

    2009-01-01

    3D seismic parameters can reflect the features of petroleum reservoir from different profiles. By analizing the3D seismic parameters, we can assess the parameters of the reservoir characterization, such as deposition,structure and growth history, fluid saturation and so on. The traditional clustering methods can’t capture thedegree of similarity between reservoir parameters very well, so we introduced in this paper the application offuzzy C-means (FCM) clustering for the processing of 3D seis...

  7. Seismic performance of a novel 3D isolation system on continuous bridges

    Ou, J. P.; Jia, J. F.

    2010-04-01

    Remarkable vertical seismic motion is one of the prominent characteristics of the near-fault earthquake motions, but the traditional and widely used base isolation system only can effectively mitigate horizontal seismic responses and structural damage. A promising three-dimensional (3D) seismic isolation bearing, consisting of laminated rubber bearing with lead core (LRB) and combined coned disc spring with vertical energy dissipation device (e.g., inner fluid viscous cylindric damper or steel damper), was proposed to mitigate horizontal and vertical structural seismic responses simultaneously and separately. Three-group seismic ground motion records were selected to validate the effectiveness of the proposed 3D seismic isolation bearing on a continuous slab bridge. The appropriate damping of the vertical damping device was presented by parametric study. The analyses results showed that the proposed 3D isolation bearing is essentially effective to mitigate vertical and horizontal structural seismic response simultaneously. Near-fault pulse-type seismic motions should be considered in seismic isolation design and evaluation. The proper damping ratio of the vertical damping device should be 20%-30% for favorable vertical isolation effectiveness. The proposed 3D seismic isolation bearing is promising to be applied to the mediate-to-short span bridge and even some building structures.

  8. Assessing a 3D smoothed seismicity model of induced earthquakes

    Zechar, Jeremy; Király, Eszter; Gischig, Valentin; Wiemer, Stefan

    2016-04-01

    As more energy exploration and extraction efforts cause earthquakes, it becomes increasingly important to control induced seismicity. Risk management schemes must be improved and should ultimately be based on near-real-time forecasting systems. With this goal in mind, we propose a test bench to evaluate models of induced seismicity based on metrics developed by the CSEP community. To illustrate the test bench, we consider a model based on the so-called seismogenic index and a rate decay; to produce three-dimensional forecasts, we smooth past earthquakes in space and time. We explore four variants of this model using the Basel 2006 and Soultz-sous-Forêts 2004 datasets to make short-term forecasts, test their consistency, and rank the model variants. Our results suggest that such a smoothed seismicity model is useful for forecasting induced seismicity within three days, and giving more weight to recent events improves forecast performance. Moreover, the location of the largest induced earthquake is forecast well by this model. Despite the good spatial performance, the model does not estimate the seismicity rate well: it frequently overestimates during stimulation and during the early post-stimulation period, and it systematically underestimates around shut-in. In this presentation, we also describe a robust estimate of information gain, a modification that can also benefit forecast experiments involving tectonic earthquakes.

  9. Marine biota sightings during 3D marine seismic surveys

    Oliveira, Joao Luiz Martinez de; Uller, George A. [CGG do Brasil, Rio de Janeiro, RJ (Brazil); Derntl, Jose Renato; Ribeiro, Camila Castroviejo da Silva; Pereira, Edisio [GEOCOOP Cooperativa de Trabalho, Rio de Janeiro, RJ (Brazil); Miranda, Cristina Maschio de [Nautilus Cooperativa de Trabalho (Brazil); Ferraz, Alexandre Almeida; Costa, Leandro Damiao Soares da [Okeanos Consultoria e Meio Ambiente Ltda. (Brazil)

    2004-07-01

    This work intends to make a correlation between the presence of the marine biota and the seismic source activity (air guns) during seismic surveys, in Campos (BM-C-25 and BM-C-16) and Santos (BM-S-3) Basin, since July 2003 until March 2004. Environmental data were acquired onboard of the Seismic Vessel CGG Harmattan by a team of four oceanographers (environmental technicians), working on the highest place of the Vessel to record and identify the animals whenever was possible. The data were recorded in forms where fields about the biotic and environmental aspects were filled. In 212 days of observations, 2580,1 hours of sighting's effort were recorded; the air guns worked during 37,6% of the time of the effort. These efforts were made during the daylight reaching an average value of 11,35 hours/day. Sightings were divided into the suborders Odontocetes and Mysticetes, and others (fishes, turtles and non identified mammals). 175 sightings were recorded, being 54% when the air gun was off (24% Mysticetes, 56% Odontocetes, 20% others). Similarly, when the air gun was working, 46% of the records were made (24% Mysticetes, 61% Odontocetes, 6% others); the major concentration (58%) of individuals was inside the 1000 m radius around the ship, followed by 14% of the individuals occurring between 3001-4000 m radius away from the ship. The analysis of the data suggests a non-evasive behavior related to the working of the seismic source, corroborating the results reached by other publications using the data collected onboard CGG Vessels. (author)

  10. Application Results of 3-D Seismic Exploration Technology in Coal Mines

    SUN Shenglin; WU Xizun

    2004-01-01

    This paper briefly introduces the development and present situation of China's coal seismic exploration. It focuses on analyzing the important functions of 3-D seismic exploration technology in the designing and production of coal mines, and also the results of its application.

  11. A 3D numerical investigation of reservoir monitoring with borehole radar and its application in smart well

    Zhou, F.; Miorali, M.; Slob, E. C.; Arts, R.

    2011-12-01

    Smart wells, a new generation of wells used in oil production, combine down-hole monitoring and control of the reservoir flow. Smart technology allows the implementation of proactive strategies that can mitigate potential problems, such as the approach of undesired fluids, before they impact production from the well. The effectiveness of the proactive strategies depends on the ability of monitoring the near-well region. We propose that borehole radar is a promising technology for this purpose. We couple 3D reservoir flow modeling with 3D radar modeling. The time-lapse analysis of the electromagnetic simulations confirms that radar can map the movement of the oil-water contact in a range of 1-10 m from the well. The comparison of the 3D reflected signals with the 2D show a good correlation, which allows cheaper simulation for a large-scale reservoir model. We use the radar results to implement a proactive control strategy in a realistic reservoir scenario. The NPV(Net Present Value) has improved by controlling the production according to the modeled radar measurements. We suggest borehole radar as a promising application in oil production optimization if an effective smart well control strategy is combined.

  12. Geo-pressure prediction from 3-D seismic data: case studies from the gulf of Mexico

    Kan, T.K.; Kilsdonk, B. [ARCO Exploration and Production Technology, Plano TX (United States)

    1999-04-01

    We have developed a hypothesis and technique to interpret overpressure in both shales and sandstones by combining 3-D seismic geo-pressure estimates with 3-D interpretation of sandstone horizons. Before we can accept them, these ideas must be tested with measured pressure data from areas with 3-D geo-pressure cubes. Additionally, Our technique depends strongly on interpreting the lateral continuity of permeable units. We hope to improve our pre-drill prediction capability by incorporating both seismic-stratigraphic and impedance based facies interpretation techniques. (author)

  13. Seismic methods for the characterisation of reservoirs in developing old natural gas fields in Germany; 3D Seismische Verfahren zur Reservoircharakterisierung bei der Entwicklung alter Erdoelfelder in Deutschland

    Krajewski, P.; Stahl, E.; Bischoff, R. [Preussag Energie GmbH, Lingen (Germany); Guderian, K.; Hasse, G.; Schmiermann, I. [BEB Erdoel und Erdgas GmbH, Hannover (Germany); Groot, P. de [De Groot-Bril Earth Sciences BV, Enschede (Netherlands)

    1998-12-31

    Two examples are chosen to describe the possiblities and limitations of using 3D seismic data for the interpretation of structures and the seismic characterisation of reservoirs. New techniques of seismic classification offer a great deal of possibilities, especially if - as in the case of Ruehme - there is a sufficiency of data from many borehole locations which enables the training of algorithms.(orig.) [Deutsch] Anhand zweier Beispiele wurden die Moeglichkeiten aber auch die Grenzen des Einsatzes 3D seismischer Daten bei der strukturellen Interpretation und der seismischen Reservoircharakterisierung aufgezeigt. Neuartige Techniken der seismischen Klassifizierung erweitern die Moeglichkeiten dabei betraechtlich, insbesondere, wenn - wie beim Beispiel Ruehme - durch die vielen Bohrlokationen ausreichend Daten zum Trainieren der Algorithmen zur Verfuegung stehen. (orig.)

  14. Enhanced imaging of CO2 at the Ketzin storage site: Inversion of 3D time-lapse seismic data

    Gil, M.; Götz, J.; Ivanova, A.; Juhlin, C.; Krawczyk, C. M.; Lüth, S.; Yang, C.

    2012-04-01

    The Ketzin test site, located near Berlin, is Europe's longest-operating on-shore CO2 storage site. As of December 2011, more than 56,000 tons of food grade CO2 has been injected since June 2008 in an anticlinal structure of the Northeast German Basin. The target reservoir consists of porous, brine bearing sandstone units of the Upper Triassic Stuttgart Formation at approximately 630 to 650 m depth. In order to enhance the understanding of the structural geometry of the site and to investigate the extension of the CO2-plume, several geophysical monitoring methods are being applied at Ketzin, among these are active seismic measurements, geoelectrics and borehole measurements. Among the various seismic techniques (e.g. 2D reflection surveys, crosshole tomography, Vertical Seismic Profiling, 2D- and 3D-Moving Source Profiling) employed at this pilot site, 3D time-lapse reflection surveys are an important component. The baseline 3D survey was acquired in 2005 and the first repeat measurements were performed in 2009 after injection of about 22,000 tons of CO2. The second repeat survey is planned to be carried out in fall 2012. These measurements allow the time-lapse signature of the injected CO2 to be imaged. The time-lapse amplitude variation attributed to the injected CO2 in the reservoir matches, considering detection limits of seismic surface measurements, the expected distribution of the CO2 plume derived from reservoir simulations. Previous attempts towards a quantitative interpretation were based on integrative considerations of different types of geophysical measurements using strict assumptions and characterized by large error bars. In order to increase the resolution and reliability of the data and to improve estimation of rock properties and especially to enhance the imaging resolution of the CO2-plume, the time-lapse 3D seismic data have now been inverted for seismic impedances with different methods, which is the focus of this presentation. One difficulty

  15. 3-D pneumatic seismic isolation of nuclear power plants

    This paper describes the work carried at the Russian Federation Research Center of Fundamental Engineering (RCFE), in development of innovative pneumatic multicomponent low-frequency seismic isolation bearings for advanced nuclear power plants.This device incorporates both supporting spherical elements, which provide displacements in the horizontal direction, and pneumatic dampers with rubber diaphragms for displacement in the vertical direction. To decrease the relative displacements of the isolated object the system uses viscoelastic dampers. Damping devices had been specially elaborated for the reactor building seismic isolation system as a result of substantial advances in the design and operation of the HD-type hydrodampers, created at the CKTI VIBROSEISM. The procedures developed have been used for comparison of the test and computer data on model isolated steel structure (MISS) and isolated rigid mass (IRM) isolators produced by ENEA and KAERI. Most recent work has concentrated on the development of mathematical models of isolators and isolated nuclear structures. Force-deformation characteristics of the HDRB model had been calculated on the basis of a special method of non-linear elastic theory using the continual transformations method. (author)

  16. Application of Catastrophe Theory in 3D Seismic Data Interpretation of Coal Mine

    ZHAO Mu-hua; YANG Wen-qiang; CUI Hui-xia

    2005-01-01

    In order to detect fault exactly and quickly, cusp catastrophe theory is used to interpret 3D coal seismic data in this paper. By establishing a cusp model, seismic signal is transformed into standard form of cusp catastrophe and catastrophe parameters, including time-domain catastrophe potential, time-domain catastrophe time, frequency-domain catastrophe potential and frequency- domain degree, are calculated. Catastrophe theory is used in 3D seismic structural interpretation in coal mine. The results show that the position of abnormality of the catastrophe parameter profile or curve is related to the location of fault, and the cusp catastrophe theory is effective to automatically pick up geology information and improve the interpretation precision in 3D seismic data.

  17. 3-D seismic mapping and amplitude analysis: a Gulf of Mexico case history

    Kidney, R.L.; Silver, R.S.; Hussein, H.A. (Oryx Energy Co. (United States))

    1992-01-01

    Utilization of 3-D seismic data and Direct Hydrocarbon Indicators led to the successful drilling of appraisal and development wells in the Gulf of Mexico block South Timbalier 198 (ST 198), significantly reducing time and cost. Based on 2-D seismic mapping, a Pliocene Lower Buliminella (L BUL) prospect was drilled in ST 198. An Upper Buliminella (U BUL) gas sandstone was encountered instead. An appraisal well of the U BUL interval confirmed this discovery. It became apparent that the structural complexities and the seismic amplitude anomalies of the area could not be adequately resolved using the 2-D seismic grid. A 3-D seismic survey was shot to investigate the remaining potential of ST 198. Direct Hydrocarbon Indicators (DHIs), which are seismic anomalies resulting from the hydrocarbon effect on rock properties, are generally expected from these age sands. While the 3-D survey shows a seismic amplitude anomaly associated with the U BUL reservoir, the areal extent of the anomaly did not match the findings of the two wells. A DHI study was performed to determine if this inconsistency could be explained and if the anomaly could be used in the well planning. The two key steps which confirmed that this amplitude anomaly is a DHI were properly calibrating the seismic data to the well control and determining the theoretical seismic response of the gas sandstones. The DHI study along with the 3-D mapping led to the successful development of the ST 198 U BUL reservoir and to setting up a successful adjacent fault block play. Finally, 3-D mapping also identified a L BUL trap updip from the original L BUL prospect which resulted in a successful drilling effort. (author).

  18. First images and orientation of internal waves from a 3-D seismic oceanography data set

    T. M. Blacic

    2009-10-01

    Full Text Available We present 3-D images of ocean finestructure from a unique industry-collected 3-D multichannel seismic dataset from the Gulf of Mexico that includes expendable bathythermograpgh casts for both swaths. 2-D processing reveals strong laterally continuous reflectors throughout the upper ~800 m as well as a few weaker but still distinct reflectors as deep as ~1100 m. Two bright reflections are traced across the 225-m-wide swath to produce reflector surface images that show the 3-D structure of internal waves. We show that the orientation of internal wave crests can be obtained by calculating the orientations of contours of reflector relief. Preliminary 3-D processing further illustrates the potential of 3-D seismic data in interpreting images of oceanic features such as internal wave strains. This work demonstrates the viability of imaging oceanic finestructure in 3-D and shows that, beyond simply providing a way to see what oceanic finestructure looks like, quantitative information such as the spatial orientation of features like internal waves and solitons can be obtained from 3-D seismic images. We expect complete, optimized 3-D processing to improve both the signal to noise ratio and spatial resolution of our images resulting in increased options for analysis and interpretation.

  19. First images and orientation of fine structure from a 3-D seismic oceanography data set

    T. M. Blacic

    2010-04-01

    Full Text Available We present 3-D images of ocean fine structure from a unique industry-collected 3-D multichannel seismic dataset from the Gulf of Mexico that includes expendable bathythermograph casts for both swaths. 2-D processing reveals strong laterally continuous reflections throughout the upper ~800 m as well as a few weaker but still distinct reflections as deep as ~1100 m. We interpret the reflections to be caused by reversible fine structure from internal wave strains. Two bright reflections are traced across the 225-m-wide swath to produce reflection surface images that illustrate the 3-D nature of ocean fine structure. We show that the orientation of linear features in a reflection can be obtained by calculating the orientations of contours of reflection relief, or more robustly, by fitting a sinusoidal surface to the reflection. Preliminary 3-D processing further illustrates the potential of 3-D seismic data in interpreting images of oceanic features such as internal wave strains. This work demonstrates the viability of imaging oceanic fine structure in 3-D and shows that, beyond simply providing a way visualize oceanic fine structure, quantitative information such as the spatial orientation of features like fronts and solitons can be obtained from 3-D seismic images. We expect complete, optimized 3-D processing to improve both the signal to noise ratio and spatial resolution of our images resulting in increased options for analysis and interpretation.

  20. Development of the Borehole 2-D Seismic Tomography Software Using MATLAB

    Nugraha, A. D.; Syahputra, A.; Fatkhan, F.; Sule, R.; Hendriyana, A.

    2011-12-01

    We developed 2-D borehole seismic tomography software that we called "EARTHMAX-2D TOMOGRAPHY" to image subsurface physical properties including P-wave and S-wave velocities between two boreholes. We used Graphic User Interface (GUI) facilities of MATLAB programming language to create the software. In this software, we used travel time of seismic waves from source to receiver by using pseudo bending ray tracing method as input for tomography inversion. We can also set up a model parameterization, initial velocity model, ray tracing processes, conduct borehole seismic tomography inversion, and finally visualize the inversion results. The LSQR method was applied to solve of tomography inversion solution. We provided the Checkerboard Test Resolution (CTR) to evaluate the model resolution of the tomography inversion. As validation of this developed software, we tested it for geotechnical purposes. We then conducted data acquisition in the "ITB X-field" that is located on ITB campus. We used two boreholes that have a depth of 39 meters. Seismic wave sources were generated by impulse generator and sparker and then they were recorded by borehole hydrophone string type 3. Later on, we analyzed and picked seismic arrival time as input for tomography inversion. As results, we can image the estimated weathering layer, sediment layer, and basement rock in the field depicted by seismic wave structures. More detailed information about the developed software will be presented. Keywords: borehole, tomography, earthmax-2D, inversion

  1. 3-D seismic and reservoir modeling, ram prospect, Viosca Knoll Block 912, offshore Gulf of Mexico

    Carew, W.; Ostendorf, P.F. (Exxon Company, New Orleans, LA (United States)); Krum, G.K. (Exxon Exploration Company, Houston, TX (United States))

    1993-09-01

    Ram prospect is a large stratigraphic trap located in Viosca Knoll Block 912/956/957, offshore Alabama in 3500-ft water depth. Reservoirs are Pliocene and Miocene gas- and oil-bearing deep-water sands deposited as fan complexes in an intraslope basin. The field has been proved by a total of 12 well penetrations and is nearing the development stage. In an effort to predict reservoir performance and recovery efficiencies, we constructed three-dimensional (3-D) reservoir models Exxon's in-house 3-D modeling program (GEOSET). Reservoir simulation studies will be based upon these 3-D geological models. We used 3-D seismic data to map seismic attributes around the prospect and well control to calibrate the seismic attributes based on known reservoir characteristics, thereby deriving a facies map for the entire field. Top/base structure, gross isopach, facies polygons, porosity, and Vshale were input into GEOSET to define the overall reservoir container and fill. The paucity of well data was compensated by using the 3-D-seismic based facies as a guide to filling polygons and by creating [open quotes]pseudowells[close quotes] from the real well data. These pseudowells aided in correlating within and between polygons. The resulting 3-D models (total porosity, effective porosity, Vsand) faithfully reflect the heterogeneity inferred from both 3-D seismic data and well control and provide visualization of reservoir continuity much better than models derived from well data alone. The models serve as a framework within which one can perform reservoir simulations and run various sensitivities. Additionally, the GEOSET porosity models can provide an alternative reservoir volume calculation.

  2. Near-surface 3D reflections seismic survey; Sanjigen senso hanshaho jishin tansa

    Nakahigashi, H.; Mitsui, H.; Nakano, O.; Kobayashi, T. [DIA Consultants Co. Ltd., Tokyo (Japan)

    1997-05-27

    Faults are being actively investigated across Japan since the Great Hanshin-Awaji Earthquake. Discussed in this report is the application of the 3D near-surface reflection seismic survey in big cities. Data from trenching and drilling is used for the geological interpretation of the surroundings of a fault, and the reflection seismic survey is used to identify the position, etc., of the fault. In this article, when the results obtained from the experimental field are examined, it is found that the conventional 2D imaging reflection survey betrays the limit of its capability when the geological structure is complicated, that the 3D reflection seismic survey, on the contrary, is capable of high-precision imaging and, when augmented by drilling, etc., becomes capable of a more detailed interpretation, and that it also contributes effectively to the improvement of local disaster prevention in big cities. Using as the model the Tachikawa fault that runs near JR Tachikawa Station, embodiment of the 3D reflection seismic survey is reviewed. For the acquisition of data excellent in quality in a 3D reflection seismic survey conducted utilizing the roads in the sector chosen for experiment in the urban area, the shock generating points and receiving points should be positioned by taking into account the parameters in the bin arranging process so that the mid-points will be regularly distributed on the surface. 3 refs., 11 figs., 1 tab.

  3. METHODOLOGY IMPLEMENTED FOR THE 3D-SEISMIC MODELLING USING GOCAD AND NORSAR 3D SOFTWARE APPLIED TO COMPLEX AREAS IN THE LLANOS FOOTHILLS

    Piedrahita Carlos

    2007-06-01

    Full Text Available A methodology has been applied in order to use seismic modeling and generate synthetic data which are compared with results from field data. This methodology has been applied to the Sirirí area and
    subsequently it has been extended to other geographic areas. To fully develop this methodology, the GOCAD and 3D NORSAR software packages were used to build respectively the geological and 3D seismic models. This methodology involves making structural modeling by edition of the different objects (horizons and faults in the structural module of GOCAD, with the help of available seismic and well data, in order to be consistent with reality. From this result a valid seismic model is imported to NORSAR 3D for making the seismic modeling, using ray tracing to get synthetic data. Finally, this information is compared with field data that has been processed.

  4. Application of 3D Seismic Data Inversion to Coal Mining Prospecting

    2005-01-01

    Seismic inversion is one of the most important methods for lithological prospecting . Seismic data with low resolution is converted into impedance data of high resolution which can reflect the geological structure by inversion The inversion technique of 3D seismic data is discussed from both methodological and theoretical aspects, and the inversion test is also carried out using actual logging data. The result is identical with the measured data obtained from roadway of coal mine. The field tests and research results indicate that this method can provide more accurate data for identifying thin coal seam and minor faults.

  5. Automatic detection of karstic sinkholes in seismic 3D images using circular Hough transform

    Heydari Parchkoohi, Mostafa; Keshavarz Farajkhah, Nasser; Salimi Delshad, Meysam

    2015-10-01

    More than 30% of hydrocarbon reservoirs are reported in carbonates that mostly include evidence of fractures and karstification. Generally, the detection of karstic sinkholes prognosticate good quality hydrocarbon reservoirs where looser sediments fill the holes penetrating hard limestone and the overburden pressure on infill sediments is mostly tolerated by their sturdier surrounding structure. They are also useful for the detection of erosional surfaces in seismic stratigraphic studies and imply possible relative sea level fall at the time of establishment. Karstic sinkholes are identified straightforwardly by using seismic geometric attributes (e.g. coherency, curvature) in which lateral variations are much more emphasized with respect to the original 3D seismic image. Then, seismic interpreters rely on their visual skills and experience in detecting roughly round objects in seismic attribute maps. In this paper, we introduce an image processing workflow to enhance selective edges in seismic attribute volumes stemming from karstic sinkholes and finally locate them in a high quality 3D seismic image by using circular Hough transform. Afterwards, we present a case study from an on-shore oilfield in southwest Iran, in which the proposed algorithm is applied and karstic sinkholes are traced.

  6. Rupture Process for Hayward Microearthquakes Inferred from Borehole Seismic Recordings

    Taira, T.; Dreger, D. S.; Nadeau, R. M.

    2014-12-01

    The Hayward fault (HF) in the San Francisco Bay Area, California is one of the major strands of the San Andreas fault system, extending for about 70 km. Crustal deformation along the HF is characterized by a wide variety of fault slip behaviors from aseismic creep to stick-slip earthquake including a Mw ~6.8 earthquake in 1868. We here document the high-resolution imaging of the rupture models for the recent M 3+ HF earthquakes by making use of waveforms from the Hayward Fault Network (HFN). The HFN is an array of borehole seismic instrumentation and provides an unprecedented high-resolution coverage of the earthquake source study for HF earthquakes. Using the finite-source rupture inversion with an empirical Green's function approach, we find a variety of rupture propagations including subevents, directivity, and high stress drop. Our finite-source modeling reveals a complex slip distribution for the 2013 Mw 3.2 Orinda earthquake that is characterized by a patch of slip with a maximum slip of 4 cm concentrated near the hypocenter at about 6.6 km depth, with a large secondary patch of slip (peak slip of 2 cm) centered up-dip and southeast from the hypocenter at a distance of about 400 m away. The two subevents release 43% and 23% of the total seismic moment (6.7 x 1013 N m) and the inferred peak stress drops are 18 MPa and 10 MPa. The 2011 Mw 4.0 Berkeley and 2012 Mw 4.0 El Cerrito earthquakes are marked by high stress drop. The inferred peak and mean stress drops are about 130-165 MPa and 45 MPa, respectively, which suggests that there are locally high levels of the fault strength on the HF. Our finite-source modeling suggests that the radiation efficiency determined for these two earthquakes is very low (< 0.1) and implies that majority of energy is dissipated during the earthquake rupture process.

  7. Characterization of magnetized ore bodies based on three-component borehole magnetic and directional borehole seismic measurements

    Virgil, Christopher; Neuhaus, Martin; Hördt, Andreas; Giese, Rüdiger; Krüger, Kay; Jurczyk, Andreas; Juhlin, Christopher; Juhojuntti, Niklas

    2016-04-01

    In the last decades magnetic prospecting using total field data was used with great success for localization and characterization of ferromagnetic ore bodies. Especially borehole magnetic measurements reveal important constraints on the extent and depth of potential mining targets. However, due to the inherent ambiguity of the interpretation of magnetic data, the resulting models of the distribution of magnetized material, such as iron ore bodies, are not entirely reliable. Variations in derived parameters like volume and estimated ore content of the expected body have significant impact on the economic efficiency of a planned mine. An important improvement is the introduction of three-component borehole magnetic sondes. Modern tools comprise orientation modules which allow the continuous determination of the tool's heading regardless of the well inclination and independent of the magnetic field. Using the heading information the recorded three-component magnetic data can be transferred from the internal tool's frame to the geographic reference frame. The vector information yields a more detailed and reliable description of the ore bodies compared to total field or horizontal and vertical field data. Nevertheless complementary information to constrain the model is still advisable. The most important supplementary information for the interpretation of magnetic data is the knowledge of the structural environment of the target regions. By discriminating dissimilar rock units, a geometrical starting model can be derived, constraining the magnetic interpretation and leading to a more robust estimation of the rock magnetizations distribution. The most common approach to reveal the lithological setting rests upon seismic measurements. However, for deep drilling targets surface seismic and VSP lack the required spatial resolution of 10s of meters. A better resolution is achieved by using directed sources and receivers inside the borehole. Here we present the application of

  8. Offshore 3D seismic, geochemical data integration, Main Pass project, Gulf of Mexico

    Belt, J.Q. Jr.; Rice, G.K. [GeoFrontiers Corp., Dallas, TX (United States)

    1996-04-01

    A bottom cable, 3D seismic, and shallow piston-core geochemical survey was conducted in summer 1992 on Main Pass Blocks 41 and 58 in the Gulf of Mexico. The 15.5 sq mile study area is in 11--24 m (36--79 ft) of water. Two hundred seventy-six shallow, 2 m piston-core sediment samples were collected using a uniform grid pattern on 400 m (1,320 ft) spaced intervals. Retrieved sediment samples were immediately sealed in metal 1 pt cans containing biocide solution. The purpose of the 3D seismic survey and geochemical offshore data integration project was three-fold: determine if near-shore, low-cost shallow piston-core sediment samples would be affected by fluvial contamination; evaluate the efficiency of a shallow-core, dense-grid sample design program in detecting thermogenic hydrocarbons at depth; evaluate the benefits of integrating offshore, shallow sediment geochemistry with 3D seismic data in developing a petroleum geological model. All 3D seismic survey data and block boundaries, as described in illustrations and figures, are only generally located within the Main Pass Area.

  9. Identifying High Potential Well Targets with 3D Seismic and Mineralogy

    Mellors, R. J. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2015-10-30

    Seismic reflection the primary tool used in petroleum exploration and production, but use in geothermal exploration is less standard, in part due to cost but also due to the challenges in identifying the highly-permeable zones essential for economic hydrothermal systems [e.g. Louie et al., 2011; Majer, 2003]. Newer technology, such as wireless sensors and low-cost high performance computing, has helped reduce the cost and effort needed to conduct 3D surveys. The second difficulty, identifying permeable zones, has been less tractable so far. Here we report on the use of seismic attributes from a 3D seismic survey to identify and map permeable zones in a hydrothermal area.

  10. Mature field development using 3-D seismic in Minas field, Central Sumatra, Basin, Indonesia

    Fitris, F.; Whitacre, T.P. (PT Caltex Pacific Indonesia, Sumatra (Indonesia))

    1996-01-01

    The Minas field 3-D seismic survey (450 km2) was conducted after nearly 4000 MMBO of production. Interpretation of the data has shown a significant number of remaining prospects within the field. Delineation of these locations was impossible using the 2D seismic grid. The new 3D data cube has revealed locations in simple anticlines, en-echelon folds, faulted monoclines, rollover folding, complex faulted zones, stratigraphic traps and within a fractured basement high. The new interpretation has identified more than 75 development and OSWC well locations. These wells will produce an estimated 75 MMBO. As the result of a $5MM seismic survey, the asset value will increase by nearly $1000MM.

  11. Mature field development using 3-D seismic in Minas field, Central Sumatra, Basin, Indonesia

    Fitris, F.; Whitacre, T.P. [PT Caltex Pacific Indonesia, Sumatra (Indonesia)

    1996-12-31

    The Minas field 3-D seismic survey (450 km2) was conducted after nearly 4000 MMBO of production. Interpretation of the data has shown a significant number of remaining prospects within the field. Delineation of these locations was impossible using the 2D seismic grid. The new 3D data cube has revealed locations in simple anticlines, en-echelon folds, faulted monoclines, rollover folding, complex faulted zones, stratigraphic traps and within a fractured basement high. The new interpretation has identified more than 75 development and OSWC well locations. These wells will produce an estimated 75 MMBO. As the result of a $5MM seismic survey, the asset value will increase by nearly $1000MM.

  12. ) A Feasibility Study for High Resolution 3D Seismic In The Deep Offshore Nigeria

    The conventional Exploration 3D seismic in the Deep Offshore Nigeria is typically acquired with 4000m-6000m cable length at 6-8 depth and with flip-flop shooting, providing a shot point interval of 50m. the average resulting frequency content is typically between 10-60hz which is adequate for exploration interpretation. It has become common in the last few years. E.g. in Angola and the Gulf of Mexico, to re-acquire High Resolution 3D seismic, after a discovery, to improve definition of turbidite systems and accuracy of reservoir geometry for optimized delineation drilling. This feasibility study which was carried out in three different steps was due to the question on whether HR-Seismic should be acquired over TotalFinaElf AKPO discovery for optimized delineation drilling

  13. Evaluation and assessment of the seismic responses of 3-D base-isolated structures

    Hueffmann, G.K.; Sutton, W.T. [GERB Vibration Control Systems, Inc., Westmont, IL (United States)

    1995-12-01

    The 1994 Northridge earthquake offered the opportunity to evaluate and assess the seismic response of several base-isolated buildings. Assessment of 2-D base isolation is straightforward comparing separately the uncoupled horizontal and vertical building motions to the corresponding ground motions. With 3-D systems characterized by low vertical natural frequencies, the system assessment must include rocking of the structure. Neglecting this consideration leads to an erroneous conclusion that the system greatly amplifies vertical ground accelerations. The paper evaluates the seismic response of a 3-D base-isolated building as compared to the same structure on a 2-D system. The paper also shows that the vertical accelerations measured at extreme locations in the building on a 3-D base-isolation system develop mainly from rocking responses to the horizontal ground motion.

  14. The use of exploration 3D seismic data for geohazards assessment in the Gulf of Mexico

    Gafford, W.T.

    1996-12-31

    3D seismic data, acquired for oil and gas exploration purposes, is now being used to supplement or even replace conventional high resolution geohazard surveys in some areas of the Gulf of Mexico. The use of 3D data has improved the identification and understanding of some types of geohazards, and the use of seismic interpretation workstations has made the data more accessible for geohazard analysis, and resulted in a more thorough interpretation of the shallow geologic section. Technologies used for exploration purposes have been adopted for use in the identification and assessment of drilling hazards in the near seafloor sedimentary section. Savings of time and money have been realized, as well as identification of areas where additional data is required. Some of the limitations and restrictions in using exploration 3D data have also been identified.

  15. 3D seismics for geothermal reservoir characterization - a case study from Schneeberg (Germany)

    Hlousek, F.; Hellwig, O.; Buske, S.

    2013-12-01

    We present the results of a 3D seismic survey acquired near Schneeberg in the western Erzgebirge (Germany). The aim of the project is to use seismic exploration methods to image and to characterize a major fault zone in crystalline rock which could be used as a geothermal reservoir at a target depth of about 5-6 km with expected temperatures between 160-180°C. For this purpose a high resolution 3D Vibroseis survey with more than 5300 source and approximately 8000 receiver locations was performed at the end of 2012 and covered an area of approximately 10 km x 13 km. The 3D survey was complemented by an additional wide-angle seismic survey using explosives along eleven profile lines radially centered at the target area. The region itself is dominated by the NW-SE striking Gera-Jáchymov fault system. The main geological features in the survey area are well known from intensive mining activities down to a depth of about 2 km. The seismic investigations aimed at imaging the partly steeply dipping fault branches at greater depth, in particular a dominant steeply NE dipping fault in the central part of the survey area. Beside this main structure, the Gera-Jáchymov fault zone consists of a couple of steeply SW dipping conjugated faults. Advanced processing and imaging methods have been applied to the data set. 3D Kirchhoff prestack depth migration delivered a clear image of the structure of the various fault branches at depths of around 2-5 km. Furthermore, focusing migration methods (e.g. coherency migration) have been applied and even sharpened the image such that the 3D seismic result allows for a profound characterization of this potential geothermal reservoir in crystalline rock.

  16. Integrating 3D seismic curvature and curvature gradient attributes for fracture characterization: Methodologies and interpretational implications

    Gao, Dengliang

    2013-03-01

    In 3D seismic interpretation, curvature is a popular attribute that depicts the geometry of seismic reflectors and has been widely used to detect faults in the subsurface; however, it provides only part of the solutions to subsurface structure analysis. This study extends the curvature algorithm to a new curvature gradient algorithm, and integrates both algorithms for fracture detection using a 3D seismic test data set over Teapot Dome (Wyoming). In fractured reservoirs at Teapot Dome known to be formed by tectonic folding and faulting, curvature helps define the crestal portion of the reservoirs that is associated with strong seismic amplitude and high oil productivity. In contrast, curvature gradient helps better define the regional northwest-trending and the cross-regional northeast-trending lineaments that are associated with weak seismic amplitude and low oil productivity. In concert with previous reports from image logs, cores, and outcrops, the current study based on an integrated seismic curvature and curvature gradient analysis suggests that curvature might help define areas of enhanced potential to form tensile fractures, whereas curvature gradient might help define zones of enhanced potential to develop shear fractures. In certain fractured reservoirs such as at Teapot Dome where faulting and fault-related folding contribute dominantly to the formation and evolution of fractures, curvature and curvature gradient attributes can be potentially applied to differentiate fracture mode, to predict fracture intensity and orientation, to detect fracture volume and connectivity, and to model fracture networks.

  17. Advancing New 3D Seismic Interpretation Methods for Exploration and Development of Fractured Tight Gas Reservoirs

    James Reeves

    2005-01-31

    In a study funded by the U.S. Department of Energy and GeoSpectrum, Inc., new P-wave 3D seismic interpretation methods to characterize fractured gas reservoirs are developed. A data driven exploratory approach is used to determine empirical relationships for reservoir properties. Fractures are predicted using seismic lineament mapping through a series of horizon and time slices in the reservoir zone. A seismic lineament is a linear feature seen in a slice through the seismic volume that has negligible vertical offset. We interpret that in regions of high seismic lineament density there is a greater likelihood of fractured reservoir. Seismic AVO attributes are developed to map brittle reservoir rock (low clay) and gas content. Brittle rocks are interpreted to be more fractured when seismic lineaments are present. The most important attribute developed in this study is the gas sensitive phase gradient (a new AVO attribute), as reservoir fractures may provide a plumbing system for both water and gas. Success is obtained when economic gas and oil discoveries are found. In a gas field previously plagued with poor drilling results, four new wells were spotted using the new methodology and recently drilled. The wells have estimated best of 12-months production indicators of 2106, 1652, 941, and 227 MCFGPD. The latter well was drilled in a region of swarming seismic lineaments but has poor gas sensitive phase gradient (AVO) and clay volume attributes. GeoSpectrum advised the unit operators that this location did not appear to have significant Lower Dakota gas before the well was drilled. The other three wells are considered good wells in this part of the basin and among the best wells in the area. These new drilling results have nearly doubled the gas production and the value of the field. The interpretation method is ready for commercialization and gas exploration and development. The new technology is adaptable to conventional lower cost 3D seismic surveys.

  18. Prestack reverse time migration for 3D marine reflection seismic data

    Prestack reverse time migration (RTM) is a method for imaging the subsurface using the inner product of wavefield extrapolation in shot domain and in receiver domain. It is well known that RTM is better for preserving amplitudes and phases than other prestack migrations. Since 3D seismic data is huge data volume and it needs heavy computing works, it requires parallel computing in order to have a meaningful depth image of the 3D subsurface. We implemented a parallelized version of 3D RTM for prestack depth migration. The results of numerical example for 3D SEG/EAGE salt model showed good agreement with the original geological model. We applied RTM to offshore 3D seismic reflection data. The study area is 12 × 25 km with 120 survey lines. Shot and receiver spacing is 25 m and 12.5 m. The line spacing is 100 m. Shot gathers were preprocessed to enhance signal to noise ratio and velocity model was calculated from conventional stack velocity. Both of them were used to obtain 3D image using RTM. The results show reasonable subsurface image

  19. Reservoir lithofacies analysis using 3D seismic data in dissimilarity space

    Seismic data interpretation is one of the most important steps in exploration seismology. Seismic facies analysis (SFA) with emphasis on lithofacies can be used to extract more information about structures and geology, which results in seismic interpretation enhancement. Facies analysis is based on unsupervised and supervised classification using seismic attributes. In this paper, supervised classification by a support vector machine using well logs and seismic attributes is applied. Dissimilarity as a new measuring space is employed, after which classification is carried out. Often, SFA is carried out in a feature space in which each dimension stands as a seismic attribute. Different facies show lots of class overlap in the feature space; hence, high classification error values are reported. Therefore, decreasing class overlap before classification is a necessary step to be targeted. To achieve this goal, a dissimilarity space is initially created. As a result of the definition of the new space, the class overlap between objects (seismic samples) is reduced and hence the classification can be done reliably. This strategy causes an increase in the accuracy of classification, and a more trustworthy lithofacies analysis is attained. For applying this method, 3D seismic data from an oil field in Iran were selected and the results obtained by a support vector classifier (SVC) in dissimilarity space are presented, discussed and compared with the SVC applied in conventional feature space. (paper)

  20. Using decision analysis to estimate 3-D seismic value-Minas field, Sumatra Indonesia

    Mangold, K.M.; Whitacre, T.P.; Seffibudianti (Caltex Pacific Indonesia, Sumatra (Indonesia))

    1996-01-01

    Decision Analysis has been used to estimate the value added from a 3-D seismic survey recorded over Minas field, Central Sumatra. The method involves comparing the expected values which result from the various decision options, such as acquiring 3-D or not. Probabilities must be assigned to the various branches of the decision tree. These include for example, the expected reliability of the 3-D data as well as the subsequent interpretation. Anticipated drilling results with and without 3-D are assessed after reviewing historical data and interviewing experts to obtain 10th, 50th and 90th percentile results for various scenarios. In this way the expected value, or cumulative distribution of the expected value of the 3-D can be computed and risk can be assessed. The Minas 3-D survey is the largest (450 square kilometers) of over 25 development 3-D surveys recorded by Caltex Pacific Indonesia (CPI) over its fields in Central Sumatra. This survey was conducted after nearly 50 years of production from more than 750 wells. CPI's 3-D experience has shown that increasing the subsurface resolution within complex high angle faulted areas results in new drilling locations in older mature fields such as Minas. Better knowledge of the oil producing reservoirs can also be used to optimize pattern waterflood locations, horizontal drilling and other tertiary recovery studies.

  1. Using decision analysis to estimate 3-D seismic value-Minas field, Sumatra Indonesia

    Mangold, K.M.; Whitacre, T.P.; Seffibudianti [Caltex Pacific Indonesia, Sumatra (Indonesia)

    1996-12-31

    Decision Analysis has been used to estimate the value added from a 3-D seismic survey recorded over Minas field, Central Sumatra. The method involves comparing the expected values which result from the various decision options, such as acquiring 3-D or not. Probabilities must be assigned to the various branches of the decision tree. These include for example, the expected reliability of the 3-D data as well as the subsequent interpretation. Anticipated drilling results with and without 3-D are assessed after reviewing historical data and interviewing experts to obtain 10th, 50th and 90th percentile results for various scenarios. In this way the expected value, or cumulative distribution of the expected value of the 3-D can be computed and risk can be assessed. The Minas 3-D survey is the largest (450 square kilometers) of over 25 development 3-D surveys recorded by Caltex Pacific Indonesia (CPI) over its fields in Central Sumatra. This survey was conducted after nearly 50 years of production from more than 750 wells. CPI`s 3-D experience has shown that increasing the subsurface resolution within complex high angle faulted areas results in new drilling locations in older mature fields such as Minas. Better knowledge of the oil producing reservoirs can also be used to optimize pattern waterflood locations, horizontal drilling and other tertiary recovery studies.

  2. P-Cable: New High-Resolution 3D Seismic Acquisition Technology

    Planke, Sverre; Berndt, Christian; Mienert, Jürgen; Bünz, Stefan; Eriksen, Frode N.; Eriksen, Ola K.

    2010-05-01

    We have developed a new cost-efficient technology for acquisition of high-resolution 3D seismic data: the P-Cable system. This technology is very well suited for deep water exploration, site surveys, and studies of shallow gas and fluid migration associated with gas hydrates or leaking reservoirs. It delivers unparalleled 3D seismic images of subsurface sediment architectures. The P-Cable system consists of a seismic cable towed perpendicular to a vessel's steaming direction. This configuration allows us to image an up to 150 m wide swath of the sub-surface for each sail line. Conventional 3D seismic technology relies on several very long streamers (up to 10 km long streamers are common), large sources, and costly operations. In contrast, the P-Cable system is light-weight and fast to deploy from small vessels. Only a small source is required as the system is made for relatively shallow imaging, typically above the first water-bottom multiple. The P-Cable system is particularly useful for acquisition of small 3D cubes, 10-50 km2, in focus areas, rather than extensive mapping of large regions. The rapid deployment and recovery of the system makes it possible to acquire several small cubes (10 to 30 km2) with high-resolution (50-250 Hz) seismic data in during one cruise. The first development of the P-Cable system was a cooperative project achieved by Volcanic Basin Petroleum Research (VBPR), University of Tromsø, National Oceanography Centre, Southampton, and industry partners. Field trials using a 12-streamer system were conducted on sites with active fluid-leakage systems on the Norwegian-Barents-Svalbard margin, the Gulf of Cadiz, and the Mediterranean. The second phase of the development introduced digital streamers. The new P-Cable2 system also includes integrated tow and cross cables for power and data transmission and improved doors to spread the larger cross cable. This digital system has been successfully used during six cruises by the University of Troms

  3. Seismic Readings from the Deepest Borehole in the New Madrid Seismic Zone

    Woolery, Edward W [KY Geological Survey, Univ of KY; Wang, Zhenming [KY Geological Survey, Univ of KY; Sturchio, Neil C [Dept of earth and Env. Sciences, Univ of Ill at Chicago

    2006-03-01

    Since the 1980s, the research associated with the UK network has been primarily strong-motion seismology of engineering interest. Currently the University of Kentucky operates a strong-motion network of nine stations in the New Madrid Seismic Zone. A unique feature of the network is the inclusions of vertical strong-motion arrays, each with one or two downhole accelerometers. The deepest borehole array is 260 m below the surfaces at station VASA in Fulton County, Kentucky. A preliminary surface seismic refraction survey was conducted at the site before drilling the hole at VSAS (Woolery and Wang, 2002). The depth to the Paleozoic bedrock at the site was estimated to be approximately 595 m, and the depth to the first very stiff layer (i.e. Porters Creek Clay) was found to be about 260 m. These depths and stratigraphic interpretation correlated well with a proprietary seismic reflection line and the Ken-Ten Oil Exploration No. 1 Sanger hole (Schwalb, 1969), as well as our experience in the area (Street et al., 1995; Woolery et al., 1999).

  4. 3D Seismic Experimentation and Advanced Processing/Inversion Development for Investigations of the Shallow Subsurface

    Levander, Alan Richard [Rice Univ., Houston, TX (United States). Earth Science Department; Zelt, Colin A. [Rice Univ., Houston, TX (United States). Earth Science Department

    2015-03-17

    The work plan for this project was to develop and apply advanced seismic reflection and wide-angle processing and inversion techniques to high resolution seismic data for the shallow subsurface to seismically characterize the shallow subsurface at hazardous waste sites as an aid to containment and cleanup activities. We proposed to continue work on seismic data that we had already acquired under a previous DoE grant, as well as to acquire additional new datasets for analysis. The project successfully developed and/or implemented the use of 3D reflection seismology algorithms, waveform tomography and finite-frequency tomography using compressional and shear waves for high resolution characterization of the shallow subsurface at two waste sites. These two sites have markedly different near-surface structures, groundwater flow patterns, and hazardous waste problems. This is documented in the list of refereed documents, conference proceedings, and Rice graduate theses, listed below.

  5. Large-scale 3-D seismic surveys in Gulf of Mexico - economic approach to exploration

    Graebner, R.J.

    1987-05-01

    Three-dimensional seismic surveys, designed to meet exploration requirements, were conducted in 465 OCS blocks in the Gulf of Mexico, primarily in the deep-water Flexure trend. The geology is very complex, with both salt-induced structures and structures similar to the Rocky Mountain Overthrust belt. To avoid the prohibitive costs in collecting 3-D seismic data at a spatial sample rate required to image the wide range of dips, interpolation methods, based on pattern recognition techniques, were used with a relatively sparsely sampled data collection grid. Within limits, the method is capable of interpolating both crossing and aliased seismic events. The economic impact of this approach is significant because it essentially reduces the cost of 3-D acquisition to the level normally associated with detailed 2-D surveying. However, the familiar benefits of 3-D migration are retained. Using interactive interpretation systems, the results are presented as a comprehensive series of time and event amplitude maps for structural and preliminary stratigraphic mapping. Regional amplitude maps illustrate a combination of structural, stratigraphic, and other geologic phenomena. In addition to conventional structural mapping, the 3-D data may be used to assist in understanding the salt growth history, especially its effect on sedimentation and hydrocarbon potential. It may provide a significant link between regional geology work and the detailed analysis required to develop drillable prospects.

  6. Porosity and permeability prediction of Zechstein-2-carbonates from 3D seismic data

    Trappe, H.; Krajewski, P.; Aust, S. [Deilmann Erdoel Erdgas GmbH, Lingen (Germany)

    1995-08-01

    In this study the applicability is explored of using 3D seismic data to estimate porosity and permeability for Zechstein-2-Carbonates using advanced techniques such as Neural Networks and image Processing algorithm. The study area is located in the North German Basin next to the Dutch border. About 40 wells tested the Zechstein reservoir at depth between 3000-4000m. Production of the gas fields started in the fifties/early sixties. The wells were generally drilled on structural highs mapped by 2D seismic data. In a first step a detailed seismic modelling exercise was carried in order to find a relationship between reservoir quality and seismic attributes. Moreover the influence of overburden and hanging wall layers to the seismic signature at reservoir level was investigated. In the second phase the previously obtained results were proofed by the 3D seismic. Using amplitude and acoustic impedance porosity maps of the reservoir were calculated. While the porosity maps show a high degree of confidence unfortunately the porosity-permeability relationship within the carbonates is poor. Seismic attributes and geological parameters form the input for a selforganizing Neural Network. This Neural Network was trained to characterise facies units of variable permeabilities. After successful training the network is able to predict facies and permeability as well as porosity for a given area. The last stage of the study covers the structural framework of the study area. Seismic attributes such as two way traveltime and amplitude were processed using image processing algorithms. Edge detection operators, IHS ilumination, gradient descriptors and other procedures were applied to highlight small scale faulting which is thought to be responsible for an increase the production performance.

  7. 3D Porosity Estimation of the Nankai Trough Sediments from Core-log-seismic Integration

    Park, J. O.

    2015-12-01

    The Nankai Trough off southwest Japan is one of the best subduction-zone to study megathrust earthquake fault. Historic, great megathrust earthquakes with a recurrence interval of 100-200 yr have generated strong motion and large tsunamis along the Nankai Trough subduction zone. At the Nankai Trough margin, the Philippine Sea Plate (PSP) is being subducted beneath the Eurasian Plate to the northwest at a convergence rate ~4 cm/yr. The Shikoku Basin, the northern part of the PSP, is estimated to have opened between 25 and 15 Ma by backarc spreading of the Izu-Bonin arc. The >100-km-wide Nankai accretionary wedge, which has developed landward of the trench since the Miocene, mainly consists of offscraped and underplated materials from the trough-fill turbidites and the Shikoku Basin hemipelagic sediments. Particularly, physical properties of the incoming hemipelagic sediments may be critical for seismogenic behavior of the megathrust fault. We have carried out core-log-seismic integration (CLSI) to estimate 3D acoustic impedance and porosity for the incoming sediments in the Nankai Trough. For the CLSI, we used 3D seismic reflection data, P-wave velocity and density data obtained during IODP (Integrated Ocean Drilling Program) Expeditions 322 and 333. We computed acoustic impedance depth profiles for the IODP drilling sites from P-wave velocity and density data. We constructed seismic convolution models with the acoustic impedance profiles and a source wavelet which is extracted from the seismic data, adjusting the seismic models to observed seismic traces with inversion method. As a result, we obtained 3D acoustic impedance volume and then converted it to 3D porosity volume. In general, the 3D porosities show decrease with depth. We found a porosity anomaly zone with alteration of high and low porosities seaward of the trough axis. In this talk, we will show detailed 3D porosity of the incoming sediments, and present implications of the porosity anomaly zone for the

  8. OGS improvements in 2012 in running the Northeastern Italy Seismic Network: the Ferrara VBB borehole seismic station

    Pesaresi, Damiano; Romanelli, Marco; Barnaba, Carla; Bragato, Pier Luigi; Durì, Giorgio

    2013-04-01

    The Centro di Ricerche Sismologiche (CRS, Seismological Research Center) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the Northeastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data center in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of about 100 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of Northeastern Italy. The southwestern edge of the OGS seismic network stands on the Po alluvial basin: earthquake localization and characterization in this area is affected by the presence of soft alluvial deposits. OGS ha already experience in running a local seismic network in high noise conditions making use of borehole installations in the case of the micro-seismicity monitoring of a local gas storage site for a private company. Following the ML=5.9 earthquake that struck the Emilia region around Ferrara in Northern Italy on May 20, 2012 at 02:03:53 UTC, a cooperation of Istituto Nazionale di Geofisica e Vulcanologia, OGS, the Comune di Ferrara and the University of Ferrara lead to the reinstallation of a previously existing very broad band (VBB) borehole seismic station in Ferrara. The aim of the OGS intervention was on one hand to extend its real time seismic monitoring capabilities toward South-West, including Ferrara and its surroundings, and on the other hand to evaluate the seismic response at the site. We will describe improvements in running the Northeastern Italy Seismic Network, including details of the Ferrara VBB

  9. Inversion of waveforms from Xiangtang borehole seismic array for soil dynamic property

    CHEN Xue-liang; JIN Xing; TAO Xia-xin; WEI Yong-xiang

    2007-01-01

    In order to understand the site soil response of the Xiangtang borehole seismic array under real strong ground motion, reveal the site response, verify the technique of borehole exploration, and improve the precision of in-situ test and laboratory test, this paper presents a new approach, which is composed of two methods. One is the layered site seismic response method, whose layer transform matrix is always real. The other is a global-local optimization technique, which uses genetic algorithm (GA)-simplex method. An inversion of multi-component waveforms of P, SV and SH wave is carried out simultaneously. By inverting the records of three moderate and small earthquakes obtained from the Xiangtang borehole array (2# ) site, the soil dynamic characteristic parameters, including P velocity, damping ratio and frequency-dependent coefficient b, which has not been given in previous literatures, are calculated. The results show that the soil S wave velocity of the Xiangtang 2# borehole is generally greater than that obtained from the 1994 in-situ test, and is close to the velocity of the 3# borehole, which is more than 200 m away from the 2# borehole. Meanwhile, perceptible soil nonlinear behavior under peak ground motion of about 60×10-2 m/s2 is detected by the inversion analysis. The presented method can be used for studying the soil response of other borehole array sites.

  10. 3D seismic Unterhaching 2009 within hydrothermal exploration and modelling; 3D-Seismik Unterhaching 2009 im Rahmen hydrothermaler Exploration und Modellierung

    Lueschen, Ewald; Dussel, Michael; Thomas, Ruediger; Schulz, Ruediger [Leibniz-Institut fuer Angewandte Geophysik (LIAG), Hannover (Germany)

    2011-10-24

    Within the exploration of hydrothermal reservoirs, results of 3D reflexion-seismic measurements are presented. These measurements were performed in June / July 2009 according to the vibroseis method on an area of 26.3 square kilometers in the area Unterhaching (Federal Republic of Germany). The 3D seismic survey exhibits much more complex structures than previously known by 2D seismic lines. Subsequent to sinistral transtension (active in the Cretaceous to the Eocene) a short transpression impetus was performed. This is evident from graduated normal faults as well as staggered reverse fault structures and inversion structures in the Upper Jurassic. Top and base of the 600-650 m mighty Malm are well resolved. Brittle fault structures are formed linearly at the top Malm but rounded and chaotic within the Malm. This can be explained by a radical karstification / hydrothermal solution. Several circular structures are interpreted as karstified incursion structures. The seismic facies of the Malm is characterized by a shift from relatively transparent zones, layered fields, scatters and fault zones. This is an expression of smaller and larger reefs, lagoons and reef debris. Reefs are characterized by several seismic attributes. Striking low-velocity zones are oriented along the main fault zones and can be interpreted as zones that are relieved by gap porosity. Azimuth variable processing gives evidence for preferred orientations of fractures on the seismic scale. By means of the 3D seismic diverse geothermal exploration targets can be defined.

  11. 3D geological to geophysical modelling and seismic wave propagation simulation: a case study from the Lalor Lake VMS (Volcanogenic Massive Sulphides) mining camp

    Miah, Khalid; Bellefleur, Gilles

    2014-05-01

    The global demand for base metals, uranium and precious metals has been pushing mineral explorations at greater depth. Seismic techniques and surveys have become essential in finding and extracting mineral rich ore bodies, especially for deep VMS mining camps. Geophysical parameters collected from borehole logs and laboratory measurements of core samples provide preliminary information about the nature and type of subsurface lithologic units. Alteration halos formed during the hydrothermal alteration process contain ore bodies, which are of primary interests among geologists and mining industries. It is known that the alteration halos are easier to detect than the ore bodies itself. Many 3D geological models are merely projection of 2D surface geology based on outcrop inspections and geochemical analysis of a small number of core samples collected from the area. Since a large scale 3D multicomponent seismic survey can be prohibitively expensive, performance analysis of such geological models can be helpful in reducing exploration costs. In this abstract, we discussed challenges and constraints encountered in geophysical modelling of ore bodies and surrounding geologic structures from the available coarse 3D geological models of the Lalor Lake mining camp, located in northern Manitoba, Canada. Ore bodies in the Lalor lake VMS camp are rich in gold, zinc, lead and copper, and have an approximate weight of 27 Mt. For better understanding of physical parameters of these known ore bodies and potentially unknown ones at greater depth, we constructed a fine resolution 3D seismic model with dimensions: 2000 m (width), 2000 m (height), and 1500 m (vertical depth). Seismic properties (P-wave, S-wave velocities, and density) were assigned based on a previous rock properties study of the same mining camp. 3D finite-difference elastic wave propagation simulation was performed in the model using appropriate parameters. The generated synthetic 3D seismic data was then compared to

  12. Use of 3D Seismic Azimuthal Iso-Frequency Volumes for the Detection and Characterization of High Porosity/Permeability Zones in Carbonate Reservoirs

    Toelle, Brian E.

    Among the most important properties controlling the production from conventional oil and gas reservoirs is the distribution of porosity and permeability within the producing geologic formation. The geometry of the pore space within these reservoirs, and the permeability associated with this pore space geometry, impacts not only where production can occur and at what flow rates but can also have significant influence on many other rock properties. Zones of high matrix porosity can result in an isotropic response for certain reservoir properties whereas aligned porosity/permeability, such as open, natural fracture trends, have been shown to result in reservoirs being anisotropic in many properties. The ability to identify zones within a subsurface reservoir where porosity/permeability is significantly higher and to characterize them according to their geometries would be of great significance when planning where new boreholes, particularly horizontal boreholes, should be drilled. The detection and characterization of these high porosity/permeability zones using their isotropic and anisotropic responses may be possible through the analysis of azimuthal (also referred to as azimuth-limited) 3D seismic volumes. During this study the porosity/permeability systems of a carbonate, pinnacle reef within the northern Michigan Basin undergoing enhanced oil recovery were investigated using selected seismic attributes extracted from azimuthal 3D seismic volumes. Based on the response of these seismic attributes an interpretation of the geometry of the porosity/permeability system within the reef was made. This interpretation was supported by well data that had been obtained during the primary production phase of the field. Additionally, 4D seismic data, obtained as part of the CO2 based EOR project, supported reservoir simulation results that were based on the porosity/permeability interpretation.

  13. Case History of 3D Seismic Survey in Aershan Oil Field

    Lu Yousheng

    1996-01-01

    @@ Aershan Oil Field is located at the eastern end of the Manite depression .in the northeastern part of Erlian basin of North China (Fig. 1). Three oilfields -Anan, Abei and Hanan - were discovered in the Erlian basin in the early 1980s using 2D seismic survey with a very dense 0.5 km ×0.5 km grid. However. difficulties were encountered in structural delineation and lateral reservoir prediction.partly due to low signal to noise ratio and resolution of 2D section, partly due to extensive lateral variations. In order to solve these problems, large- area 3D seismic survey was conducted in the late 1980s. 3D survey area is 80 km2.This survey accurately identified the details of reservoir structures, as well as located low-relief structures. Good results were also obtained in predicting lateral reservoir variations and ascertaining oil/water contacts and oilbearing areas.

  14. Complex Crustal Structure Beneath Western Turkey Revealed by 3D Seismic Full Waveform Inversion (FWI)

    Cubuk-Sabuncu, Yesim; Taymaz, Tuncay; Fichtner, Andreas

    2016-04-01

    We present a 3D radially anisotropic velocity model of the crust and uppermost mantle structure beneath the Sea of Marmara and surroundings based on the full waveform inversion method. The intense seismic activity and crustal deformation are observed in the Northwest Turkey due to transition tectonics between the strike-slip North Anatolian Fault (NAF) and the extensional Aegean region. We have selected and simulated complete waveforms of 62 earthquakes (Mw > 4.0) occurred during 2007-2015, and recorded at (Δ Unified Seismic Network (HUSN, Greece) and Earthquake Research Center of Turkey (AFAD-DAD). The spectral-element solver of the wave equation, SES3D algorithm, is used to simulate seismic wave propagation in 3D spherical coordinates (Fichtner, 2009). The Large Scale Seismic Inversion Framework (LASIF) workflow tool is also used to perform full seismic waveform inversion (Krischer et al., 2015). The initial 3D Earth model is implemented from the multi-scale seismic tomography study of Fichtner et al. (2013). Discrepancies between the observed and simulated synthetic waveforms are determined using the time-frequency misfits which allows a separation between phase and amplitude information (Fichtner et al., 2008). The conjugate gradient optimization method is used to iteratively update the initial Earth model when minimizing the misfit. The inversion is terminated after 19 iterations since no further advances are observed in updated models. Our analysis revealed shear wave velocity variations of the shallow and deeper crustal structure beneath western Turkey down to depths of ~35-40 km. Low shear wave velocity anomalies are observed in the upper and mid crustal depths beneath major fault zones located in the study region. Low velocity zones also tend to mark the outline of young volcanic areas. Our final 3D Earth model is tested using forward wave simulations of earthquakes (M ≥ 3.7) that were not used during the inversion process. The comparison of observed

  15. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA’s) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 – April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity

  16. Imaging of 3-D seismic velocity structure of Southern Sumatra region using double difference tomographic method

    Lestari, Titik, E-mail: t2klestari@gmail.com [Meteorological Climatological and Geophysical Agency (MCGA), Jalan Angkasa I No.2 Kemayoran, Jakarta Pusat, 10720 (Indonesia); Faculty of Earth Science and Technology, Bandung Institute of Technology, Jalan Ganesa No.10, Bandung 40132 (Indonesia); Nugraha, Andri Dian, E-mail: nugraha@gf.itb.ac.id [Global Geophysical Research Group, Faculty of Mining and Petroleum Engineering, Bandung Institute of Technology, Jalan Ganesa 10 Bandung 40132 (Indonesia)

    2015-04-24

    Southern Sumatra region has a high level of seismicity due to the influence of the subduction system, Sumatra fault, Mentawai fault and stretching zone activities. The seismic activities of Southern Sumatra region are recorded by Meteorological Climatological and Geophysical Agency (MCGA’s) Seismograph network. In this study, we used earthquake data catalog compiled by MCGA for 3013 events from 10 seismic stations around Southern Sumatra region for time periods of April 2009 – April 2014 in order to invert for the 3-D seismic velocities structure (Vp, Vs, and Vp/Vs ratio). We applied double-difference seismic tomography method (tomoDD) to determine Vp, Vs and Vp/Vs ratio with hypocenter adjustment. For the inversion procedure, we started from the initial 1-D seismic velocity model of AK135 and constant Vp/Vs of 1.73. The synthetic travel time from source to receiver was calculated using ray pseudo-bending technique, while the main tomographic inversion was applied using LSQR method. The resolution model was evaluated using checkerboard test and Derivative Weigh Sum (DWS). Our preliminary results show low Vp and Vs anomalies region along Bukit Barisan which is may be associated with weak zone of Sumatran fault and migration of partial melted material. Low velocity anomalies at 30-50 km depth in the fore arc region may indicated the hydrous material circulation because the slab dehydration. We detected low seismic seismicity in the fore arc region that may be indicated as seismic gap. It is coincides contact zone of high and low velocity anomalies. And two large earthquakes (Jambi and Mentawai) also occurred at the contact of contrast velocity.

  17. Effect of Damping and Yielding on the Seismic Response of 3D Steel Buildings with PMRF

    Alfredo Reyes-Salazar; Achintya Haldar; Ramon Eduardo Rodelo-López; Eden Bojórquez

    2014-01-01

    The effect of viscous damping and yielding, on the reduction of the seismic responses of steel buildings modeled as three-dimensional (3D) complex multidegree of freedom (MDOF) systems, is studied. The reduction produced by damping may be larger or smaller than that of yielding. This reduction can significantly vary from one structural idealization to another and is smaller for global than for local response parameters, which in turn depends on the particular local response parameter. The unc...

  18. Mapping permeable fractures at depth in crystalline metamorphic shield rocks using borehole seismic, logging, and imaging

    Chan, J.; Schmitt, D. R.; Nieuwenhuis, G.; Poureslami Ardakani, E.; Kueck, J.; Abasolo, M. R.

    2012-04-01

    The presence of major fluid pathways in subsurface exploration can be identified by understanding the effects of fractures, cracks, and microcracks in the subsurface. Part of a feasibility study of geothermal development in Northern Alberta consists of the investigation of subsurface fluid pathways in the Precambrian basement rocks. One of the selected sites for this study is in the Fort McMurray area, where the deepest well drilled in the oilsands region in Northeastern Alberta is located. This deep borehole has a depth of 2.3 km which offers substantial depth coverage to study the metamorphic rocks in the Precambrian crystalline basement of this study area. Seismic reflection profiles adjacent to the borehole reveal NW-SE dipping reflectors within the metamorphic shield rocks some of which appear to intersect the wellbore. An extensive logging and borehole seismic program was carried out in the borehole in July, 2011. Gamma ray, magnetic susceptibility, acoustic televiewer, electrical resistivity, and full-waveform sonic logs were acquired to study the finer scale structure of the rock formations, with vertical resolutions in the range of 0.05 cm to 80 cm. These logs supplement earlier electrical microscanner images obtained by the well operator when it was drilled. In addition, we are also interested in identifying other geological features such as zones of fractures that could provide an indication of enhanced fluid flow potential - a necessary component for any geothermal systems to be viable. The interpretation of the borehole logs reveals a highly conductive 13 m thick zone at 1409 m depth that may indicate communication of natural brines in fractures with the wellbore fluid. The photoelectric factor and magnetic susceptibility also appear anomalous in this zone. Formation MicroImager (FMI) log was used to verify the presence of fractures in the borehole in this conductive zone. This fracture zone may coincide with the dipping seismic reflectors in the

  19. 3-D seismic facies analysis of a reefal buildup, offshore North Sumatra

    Alexander, W.L.; Nellia, M.R. (Mobil Oil Indonesia, Jakarta (Indonesia))

    1994-07-01

    The [open quotes]A[close quotes] field is located on the Sunda shelf, offshore north Sumatra. The A-1 discovery well, drilled in 1972, found hydrocarbon gas in middle Miocene carbonate rocks of reefal origin. Six appraisal wells were subsequently drilled, the most recent in late 1990. Because of drilling problems, mainly lost circulation in the carbonate reservoir, the well data obtained from the appraisal program was generally disappointing. Prior to development of the offshore area, an extensive 3-D seismic survey was shot, a portion of which covered the [open quotes]A[close quotes] field. Interpretation of the 3-D data over the [open quotes]A[close quotes] field identified different seismic facies within the carbonate reservoir. These seismic facies have been integrated with the geological data in order to construct a depositional model for the field. The seismic facies analysis was critical for developing the model because of the inadequate geological data obtained from the wells. Three distinct facies could be identified on the 3-D seismic data and correlated with the well data: reef, near-reef and inter-reef. The main concerns this facies mapping addressed were reserve determination, areas of severe lost circulation, and the distribution of dolomite. The near-reef and inter-reef areas were found to have better reservoir properties than the reef core, thereby impacting reserve calculations. In addition, the reef facies, with zones of vuggy to near cavernous type porosity, was correlatable to wells that had experienced severe lost circulation. Finally, dolomite was found to occur only within the reef facies, enabling its distribution to be predicted.

  20. Detection of coalbed fractures with P-wave azimuthal AVO in 3-D seismic exploration

    LI Guofa; PENG Suping; HE Bingshou; PENG Xiaobo; YUAN Chunfang; HU Chaoyuan

    2005-01-01

    The detection of fractures is important for production and safety in coal fields. Subsurface fractures result in azimuthal anisotropy of the seismic wave, and the amplitude of reflection wave varies with offset and azimuth.In case of weak anisotropy, the reflection coefficients of P-wave are concisely denoted as the analytic function of fracture parameters. For the purpose of predicting the coalbed fracture distribution through analyzing variation of the reflection amplitudes with offset and azimuth, 3-D seismic data with full-azimuth were acquired in a coal field in Huainan, Anhui Province. The careful analysis and process of seismic data showed that the reflection amplitude of the primary coaibed varied with azimuth in much consistent with the theoretical model. The conclusion was drawn that the coal-bed fracture in this coal field could be predicted through the method of the P-wave azimuthal AVO.

  1. Multi-dimensional Seismic Response Analysis of Base-Isolated Frame Structure with 3D Isolator

    Xiong Shishu; Huang Liting; Chen Jinfeng; Su Jingsu

    2005-01-01

    The three-dimensional lead-rubber dish-spring bearing (3DB) is proposed in this paper. The 3DB is composed of lead rubber bearing (LRB) and dish-spring bearing (DSB) with damper in series. The 3DB put forward in this paper is effective in the resolution of difficulties in strong vertical capacity and vertical damping of three-dimensional isolation bearings. It effectively suppresses rocking motions as well. The analytical model and motion equations of multi-dimensional seismic responses of 3D base-isolated frame structures are established. Taking a five-storey frame structure as an example, an extensive simulation analysis is carried out. The results show that the 3D base-isolated structure with the proposed 3DB is effective in 3D isolation; it can reduce seismic responses by 50 % compared to a non-isolated structure. Therefore, the 3D isolation problem in building can be solved easily and effectively with the 3DB proposed in this paper.

  2. Subtle traps prediction using sequence stratigraphy and 3D seismic technology: A case study from Qikou depression in Huanghua basin

    MAO Ning-bo; DAI Ta-gen; PENG Sheng-lin

    2005-01-01

    Forecasting subtle traps by sequence stratigraphy and 3D seismic data is a sensitive topic in hydrocarbon exploration. Research on subtle traps by geophysical data is the most popular and difficult. Based on the sufficiently drilling data, log data, core data and 3D seismic data, sediment sequence of Qikou depression, Huanghua basin was partitioned by using sequence stratigraphy theory. Each sediment sequence system mode was built. Sediment faces of subtle traps were pointed out. Dominating factors forming subtle traps were analyzed. Sandstone seismic rock physics and its response were studied in Tertiary System. Sandstone geophysical response and elastic modulus vary laws with pressure, temperature, porosity, depth were built. Experimental result and practice shows that it is possible using seismic information forecasting subtle traps. Integrated using geology, log, drilling data, special seismic processing technique, interpretation technique, high precision horizon calibration technique, 3D seismic visualizing interpretation, seismic coherence analysis, attribute analysis, logging-constrained inversion, time frequency analysis, subtle trapsobject is identified and interpreted. Finally, advantage object of subtle trap in this area was determined. Bottomland sand stratigraphic and lithologic reservoirs in Qinan slope zone have been founded by means of high resolution 3D seismic data field technique, high resolution 3D seismic data processing technique and seismic wave impendence inversion technique.

  3. Characterization of fracture reservoirs using static and dynamic data: From sonic and 3D seismic to permeability distribution. Annual report, March 1, 1996--February 28, 1997

    Parra, J.O.; Collier, H.A.; Owen, T.E. [and others

    1997-06-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. They also may connect the borehole to remote zones of better reservoir characteristics. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based on the effects of such conditions on the propagation of acoustic and seismic waves in the rock. The project is a study directed toward the evaluation of acoustic logging and 3D-seismic measurement techniques as well as fluid flow and transport methods for mapping permeability anisotropy and other petrophysical parameters for the understanding of the reservoir fracture systems and associated fluid dynamics. The principal application of these measurement techniques and methods is to identify and investigate the propagation characteristics of acoustic and seismic waves in the Twin Creek hydrocarbon reservoir owned by Union Pacific Resources (UPR) and to characterize the fracture permeability distribution using production data. This site is located in the overthrust area of Utah and Wyoming. UPR drilled six horizontal wells, and presently UPR has two rigs running with many established drill hole locations. In addition, there are numerous vertical wells that exist in the area as well as 3D seismic surveys. Each horizontal well contains full FMS logs and MWD logs, gamma logs, etc.

  4. Seismic signatures of partial saturation on acoustic borehole modes

    Chao, G.E.; Smeulders, D.M.J.; Van Dongen, M.E.H.

    2007-01-01

    We present an exact theory of attenuation and dispersion of borehole Stoneley waves propagating along porous rocks containing spherical gas bubbles by using the Biot theory. An effective frequency-dependent fluid bulk modulus is introduced to describe the dynamic (oscillatory) behavior of the gas bu

  5. Training toward Advanced 3D Seismic Methods for CO2 Monitoring, Verification, and Accounting

    Christopher Liner

    2012-05-31

    The objective of our work is graduate and undergraduate student training related to improved 3D seismic technology that addresses key challenges related to monitoring movement and containment of CO{sub 2}, specifically better quantification and sensitivity for mapping of caprock integrity, fractures, and other potential leakage pathways. We utilize data and results developed through previous DOE-funded CO{sub 2} characterization project (DE-FG26-06NT42734) at the Dickman Field of Ness County, KS. Dickman is a type locality for the geology that will be encountered for CO{sub 2} sequestration projects from northern Oklahoma across the U.S. midcontinent to Indiana and Illinois. Since its discovery in 1962, the Dickman Field has produced about 1.7 million barrels of oil from porous Mississippian carbonates with a small structural closure at about 4400 ft drilling depth. Project data includes 3.3 square miles of 3D seismic data, 142 wells, with log, some core, and oil/water production data available. Only two wells penetrate the deep saline aquifer. In a previous DOE-funded project, geological and seismic data were integrated to create a geological property model and a flow simulation grid. We believe that sequestration of CO{sub 2} will largely occur in areas of relatively flat geology and simple near surface, similar to Dickman. The challenge is not complex geology, but development of improved, lower-cost methods for detecting natural fractures and subtle faults. Our project used numerical simulation to test methods of gathering multicomponent, full azimuth data ideal for this purpose. Our specific objectives were to apply advanced seismic methods to aide in quantifying reservoir properties and lateral continuity of CO{sub 2} sequestration targets. The purpose of the current project is graduate and undergraduate student training related to improved 3D seismic technology that addresses key challenges related to monitoring movement and containment of CO{sub 2

  6. Probabilistic Seismic Hazard Maps for Seattle, Washington, Based on 3D Ground-Motion Simulations

    Frankel, A. D.; Stephenson, W. J.; Carver, D. L.; Williams, R. A.; Odum, J. K.; Rhea, S.

    2007-12-01

    We have produced probabilistic seismic hazard maps for Seattle using over 500 3D finite-difference simulations of ground motions from earthquakes in the Seattle fault zone, Cascadia subduction zone, South Whidbey Island fault, and background shallow and deep source areas. The maps depict 1 Hz response spectral accelerations with 2, 5, and 10% probabilities of being exceeded in 50 years. The simulations were used to generate site and source dependent amplification factors that are applied to rock-site attenuation relations. The maps incorporate essentially the same fault sources and earthquake recurrence times as the 2002 national seismic hazard maps. The simulations included basin surface waves and basin-edge focusing effects from a 3D model of the Seattle basin. The 3D velocity model was validated by modeling several earthquakes in the region, including the 2001 M6.8 Nisqually earthquake, that were recorded by our Seattle Urban Seismic Network and the Pacific Northwest Seismic Network. The simulations duplicate our observation that earthquakes from the south and southwest typically produce larger amplifications in the Seattle basin than earthquakes from other azimuths, relative to rock sites outside the basin. Finite-fault simulations were run for earthquakes along the Seattle fault zone, with magnitudes ranging from 6.6 to 7.2, so that the effects of rupture directivity were included. Nonlinear amplification factors for soft-soil sites of fill and alluvium were also applied in the maps. For the Cascadia subduction zone, 3D simulations with point sources at different locations along the zone were used to determine amplification factors across Seattle expected for great subduction-zone earthquakes. These new urban seismic hazard maps are based on determinations of hazard for 7236 sites with a spacing of 280 m. The maps show that the highest hazard locations for this frequency band (around 1 Hz) are soft-soil sites (fill and alluvium) within the Seattle basin and

  7. 3D Numerical Simulation on the Sloshing Waves Excited by the Seismic Shacking

    Zhang, Lin; Wu, Tso-Ren

    2016-04-01

    In the event of 2015 Nepal earthquake, a video clip broadcasted worldwide showed a violent water spilling in a hotel swimming pool. This sloshing phenomenon indicates a potential water loss in the sensitive facilities, e.g. the spent fuel pools in nuclear power plant, has to be taken into account carefully under the consideration of seismic-induced ground acceleration. In the previous studies, the simulation of sloshing mainly focused on the pressure force on the structure by using a simplified Spring-Mass Method developed in the field of solid mechanics. However, restricted by the assumptions of plane water surface and limited wave height, significant error will be made in evaluating the amount of water loss in the tank. In this paper, the computational fluid dynamical model, Splash3D, was adopted for studying the sloshing problem accurately. Splash3D solved 3D Navier-Stokes Equation directly with Large-Eddy Simulation (LES) turbulent closure. The Volume-of-fluid (VOF) method with piecewise linear interface calculation (PLIC) was used to track the complex breaking water surface. The time series acceleration of a design seismic was loaded to excite the water. With few restrictions from the assumptions, the accuracy of the simulation results were improved dramatically. A series model validations were conducted by compared to a 2D theoretical solution, and a 3D experimental data. Good comparisons can be seen. After the validation, we performed the simulation for considering a sloshing case in a rectangular water tank with a dimension of 12 m long, 8 m wide, 8 m deep, which contained water with 7 m in depth. The seismic movement was imported by considering time-series acceleration in three dimensions, which were about 0.5 g to 1.2 g in the horizontal directions, and 0.3 g to 1 g in the vertical direction. We focused the discussions on the kinematics of the water surface, wave breaking, velocity field, pressure field, water force on the side walls, and, most

  8. Faults survey by 3D reflection seismics; Sanjigen hanshaho jishin tansa ni yoru danso chosa

    Tsuchiya, T.; Ejiri, T.; Yamada, N.; Narita, N.; Aso, H.; Takano, H.; Matsumura, M. [Dia Consultants Company, Tokyo (Japan)

    1996-10-01

    This paper describes fault survey by 3D seismic reflection exploration. Survey has been conducted mainly at flat land area without pavement not in urban area in Japan. Subsurface structure is complicated with intersecting multiple faults. In this area, a lot of geological investigations have been done prior to the seismic reflection exploration. Fairly certain images of faults have been obtained. However, there were still unknown structures. Survey was conducted at an area of 170m{times}280m in the CDP range. Measurements were carried out by using 100 g of dynamite per seismic generation point combined with 40 Hz velocity geophones. Fixed distribution consisting of lattice points of 12{times}12 was adopted as an observation method. In and around the lattice, a great number of explosions were carried out. The CDP stacking method and the method of migration after stacking were used for the data processing. The 3D structures of six horizons and five faults could be interpreted. Interpreted horizons were well agreed with the logging results. 3 figs.

  9. 3D seismic imaging of the subsurface for underground construction and drilling

    3D seismic imaging of underground structure has been carried out in various parts of the world for various purposes. Examples shown below were introduced in the presentation. - CO2 storage in Ketzin, Germany; - Mine planning at the Millennium Uranium Deposit in Canada; - Planned Forsmark spent nuclear fuel repository in Sweden; - Exploring the Scandinavian Mountain Belt by Deep Drilling: the COSC drilling project in Sweden. The author explained that seismic methods provide the highest resolution images (5-10 m) of deeper (1-5 km) sub-surfaces in the sedimentary environment, but further improvement is required in crystalline rock environments, and the integration of geology, geophysics, and drilling will provide an optimal interpretation. (author)

  10. Intriguing Success in 3D Seismic Acquisition in Ecologically Critical Lawachara National Park of Bangladesh

    Bakht, Delawar; Siddique, Mohammad; Masud, Mohammad

    2010-09-15

    In-depth environmental studies were conducted in 2008 by a multi-disciplinary team of international and national specialists of SMEC International for Chevron Bangladesh for obtaining Environmental Clearance for 3D seismic acquisition in Moulvibazar Gas Field. This included Lawachara National Park which was declared as an ecologically critical area in 1996. Exclusive monitoring of potential impact mitigation mechanism identified through EIA studies resulted in to completing the project with intriguing success. This has displayed a glaring example of sharing expertise leading to successful initiative in technology transfer in the developing country like Bangladesh currently in dire quest of harnessing natural gas.

  11. OGS improvements in 2012 in running the North-eastern Italy Seismic Network: the Ferrara VBB borehole seismic station

    Pesaresi, D.; Romanelli, M.; Barnaba, C.; Bragato, P. L.; Durì, G.

    2014-07-01

    The Centro di Ricerche Sismologiche (CRS, Seismological Research Centre) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the North-eastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic stations, all telemetered to and acquired in real time at the OGS-CRS data centre in Udine. Real time data exchange agreements in place with other Italian, Slovenian, Austrian and Swiss seismological institutes lead to a total number of about 100 seismic stations acquired in real time, which makes the OGS the reference institute for seismic monitoring of North-eastern Italy. The south-western edge of the OGS seismic network (Fig. 1) stands on the Po alluvial basin: earthquake localization and characterization in this area is affected by the presence of soft alluvial deposits. OGS ha already experience in running a local seismic network in high noise conditions making use of borehole installations in the case of the micro-seismicity monitoring of a local gas storage site for a private company. Following the ML = 5.9 earthquake that struck the Emilia region around Ferrara in Northern Italy on 20 May 2012 at 02:03:53 UTC, a cooperation of Istituto Nazionale di Geofisica e Vulcanologia, OGS, the Comune di Ferrara and the University of Ferrara lead to the reinstallation of a previously existing very broad band (VBB) borehole seismic station in Ferrara. The aim of the OGS intervention was on one hand to extend its real time seismic monitoring capabilities toward South-West, including Ferrara and its surroundings, and on the other hand to evaluate the seismic response at the site. We will describe improvements in running the North-eastern Italy Seismic Network, including details of

  12. Estimation of 3D positions and orientations of reflectors identified in the reflection seismic survey at the Forsmark area

    The reinterpretation of the seismic data collected in the spring of 2002 in the Forsmark area confirms that the bedrock has been imaged down to depths of at least 3 km. The data quality in general and the frequency content in particular seem to allow a good resolution in identifying and discriminating reflection events in the time domain. The main difficulty resides nonetheless in determining reliably the actual 3D positions and orientations of the reflector imaged with the relatively sparse investigation layout used. If a dense survey grid on the surface were used, it would be possible to apply 3D migration procedures, which would in principle provide the locations and orientations of outstanding reflectors directly by stacking the data. The work volume to acquire and process a full 3D seismic data set would however be in a completely different class of magnitude, compared with the investigation strategy followed so far, and even so 3D seismics would not solve all problems related to the imaging of crystalline rock, e.g. imaging steeply inclined features. With the sparse array at hand, the summation from the 3D migration approach is replaced by a voting principle. That implies that a given reflector is recognized as one and the same in several profiles and a geometrical match is sought amongst the classes of solutions fitting all events identified as belonging to the same reflector. Difficulties can arise when several combinations of events produce viable solutions. This is where the voting comes in. Let it also be noted that selecting an event to form a geometrical solution makes it ineligible for alternative solutions, which raises the problem to the level of a complex combinatory approach. Our objective with the present exercise has been to investigate viable geometrical solutions for 3D reflector positions in the vicinity of the initial guesses proposed in the SKB Report R-02-43. We ventured further from the original orientation proposed only when no group of

  13. SEISVIZ3D: Stereoscopic system for the representation of seismic data - Interpretation and Immersion

    von Hartmann, Hartwig; Rilling, Stefan; Bogen, Manfred; Thomas, Rüdiger

    2015-04-01

    The seismic method is a valuable tool for getting 3D-images from the subsurface. Seismic data acquisition today is not only a topic for oil and gas exploration but is used also for geothermal exploration, inspections of nuclear waste sites and for scientific investigations. The system presented in this contribution may also have an impact on the visualization of 3D-data of other geophysical methods. 3D-seismic data can be displayed in different ways to give a spatial impression of the subsurface.They are a combination of individual vertical cuts, possibly linked to a cubical portion of the data volume, and the stereoscopic view of the seismic data. By these methods, the spatial perception for the structures and thus of the processes in the subsurface should be increased. Stereoscopic techniques are e. g. implemented in the CAVE and the WALL, both of which require a lot of space and high technical effort. The aim of the interpretation system shown here is stereoscopic visualization of seismic data at the workplace, i.e. at the personal workstation and monitor. The system was developed with following criteria in mind: • Fast rendering of large amounts of data so that a continuous view of the data when changing the viewing angle and the data section is possible, • defining areas in stereoscopic view to translate the spatial impression directly into an interpretation, • the development of an appropriate user interface, including head-tracking, for handling the increased degrees of freedom, • the possibility of collaboration, i.e. teamwork and idea exchange with the simultaneous viewing of a scene at remote locations. The possibilities offered by the use of a stereoscopic system do not replace a conventional interpretation workflow. Rather they have to be implemented into it as an additional step. The amplitude distribution of the seismic data is a challenge for the stereoscopic display because the opacity level and the scaling and selection of the data have to

  14. Microseismic Monitoring Using Surface and Borehole Seismic Stations in an Oil Field, North Oman

    El-Hussain, I.; Al-Hashmi, S.; Al-Shijbi, Y.; Al-Saifi, M.; Al-Toubi, K.; Al-Lazki, A.; Al-Kindy, F.

    2009-05-01

    Five shallow borehole seismic stations were installed to monitor microearthquake activities in a carbonate oil field in northern Oman since 1999. This shallow network of seismic station operated continuously until 2002 after which intermittent seismic recording took place due to lack of maintenance and failure of some stations. The objectives of the study are to determine the microseismic parameters in the oil field and to determine the spatial and temporal distribution of these events to evaluate possible triggering mechanism. Well over 400 microearthquakes per year were recorded in the first three years of operation and after that the level of seismic recording fell to less than 200 microearthquakes per year due to failure of some stations. In March 2008, temporary seismic experiment consisting of five near surface seismic stations were installed in the oil field to augment the shallow network station and to evaluate surface installment of seismic instrument to monitor microseismic activities. It has been recognized that microearthquakes data such as size, spatial, and temporal distribution provide information on the pressure waves initiated by either production of or injection of fluids into reservoirs. A total of 44 local microearthquake events were analyzed and located during the temporary seismic stations deployment using a non-linear location software that allows the use of variable accurate velocity model of the subsurface. The events location is confined to oil field reservoir boundary during the recording period and more events occurring at shallow depth. The correlation coefficient between gas production and number of events is the higher compared with the oil production or water injection. The focal plane solution for the largest event in the sequence indicates normal faulting with extensional stress consistent with the existing mapped normal faults in the oil field. Microseismic signal clearly detected by the collocated sensors of the near surface

  15. 3D elastic inversion of vertical seismic profiles in horizontally stratified media; Inversion elastique 3D de profils sismiques verticaux en milieux stratifies horizontalement

    Petit, J.L.

    1997-07-21

    This thesis is devoted to the inversion of VSP (vertical seismic profile) seismic data in order to determine the elastic properties of horizontally stratified media. The VSP records are computed using the full wave elastic modelling in isotropic and transversely isotropic media using Hankel transform, a finite difference scheme and an inverse Hankel transform algorithm, and the propagation equations are determined and numerically solved; the importance of considering a 3D wave propagation model instead of a 1 D one is emphasized. The theoretical VSP inverse problem is then considered, with the seismic waveform inversion set as a least-squares problem, consisting in recovering the distribution of physical parameters which minimize the misfit between calculated and observed VSP. The corresponding problem requires the knowledge of the source function

  16. Borehole seismic data processing and interpretation: New free software

    Farfour, Mohammed; Yoon, Wang Jung

    2015-12-01

    Vertical Seismic Profile (VSP) surveying is a vital tool in subsurface imaging and reservoir characterization. The technique allows geophysicists to infer critical information that cannot be obtained otherwise. MVSP is a new MATLAB tool with a graphical user interface (GUI) for VSP shot modeling, data processing, and interpretation. The software handles VSP data from the loading and preprocessing stages to the final stage of corridor plotting and integration with well and seismic data. Several seismic and signal processing toolboxes are integrated and modified to suit and enrich the processing and display packages. The main motivation behind the development of the software is to provide new geoscientists and students in the geoscience fields with free software that brings together all VSP modules in one easy-to-use package. The software has several modules that allow the user to test, process, compare, visualize, and produce publication-quality results. The software is developed as a stand-alone MATLAB application that requires only MATLAB Compiler Runtime (MCR) to run with full functionality. We present a detailed description of MVSP and use the software to create synthetic VSP data. The data are then processed using different available tools. Next, real data are loaded and fully processed using the software. The data are then integrated with well data for more detailed analysis and interpretation. In order to evaluate the software processing flow accuracy, the same data are processed using commercial software. Comparison of the processing results shows that MVSP is able to process VSP data as efficiently as commercial software packages currently used in industry, and provides similar high-quality processed data.

  17. Combination of surface and borehole seismic data for robust target-oriented imaging

    Liu, Yi; van der Neut, Joost; Arntsen, Børge; Wapenaar, Kees

    2016-05-01

    A novel application of seismic interferometry (SI) and Marchenko imaging using both surface and borehole data is presented. A series of redatuming schemes is proposed to combine both data sets for robust deep local imaging in the presence of velocity uncertainties. The redatuming schemes create a virtual acquisition geometry where both sources and receivers lie at the horizontal borehole level, thus only a local velocity model near the borehole is needed for imaging, and erroneous velocities in the shallow area have no effect on imaging around the borehole level. By joining the advantages of SI and Marchenko imaging, a macrovelocity model is no longer required and the proposed schemes use only single-component data. Furthermore, the schemes result in a set of virtual data that have fewer spurious events and internal multiples than previous virtual source redatuming methods. Two numerical examples are shown to illustrate the workflow and to demonstrate the benefits of the method. One is a synthetic model and the other is a realistic model of a field in the North Sea. In both tests, improved local images near the boreholes are obtained using the redatumed data without accurate velocities, because the redatumed data are close to the target.

  18. Analysis of Paleokarst Sinkholes in the Arkoma Basin using 3-D Seismic

    Kumbalek, Michael

    Paleokarst features are important to understand, both with regards to research geologists and to the petroleum industry. In terms of geology, understanding paleokarst features can yield more information about the depositional and surface environments of past times, and how diagenetic alteration affected the environment during the formation of karst features. In the petroleum industry, paleokarst features can have positive or negative consequence resulting in a potential reservoir with enhanced porosity due to the paleokarst features, or as a geo-hazard to prepare for or avoid when drilling. Inspired by issues faced when drilling in the Ft. Worth basin, this study utilizes multiple 3-D seismic surveys and subsurface well control to map paleokarsts within the Viola Limestone in the Arkoma Basin. Calculated seismic attribute volumes used to identify paleokarst sinkholes within the Viola Group include coherency and curvature attributes. ImageJ software was used to aid in counting and measuring paleokarst sinkholes identified using seismic mapping, coherency, and curvature attribute volumes. In addition to mapping, a cumulative distribution plot was produced from the diameters of the seismically mapped paleokarst sinkholes, allowing for an estimate to be made as to what the total amount of paleokarst sinkholes are within the study area. The methods detailed in this study proved to be effective in mapping and analyzing paleokarst sinkholes within the Viola Group. The paleokarst sinkholes mapped were determined to have been formed on the outer edge of the Southern Oklahoma aulacogen, as a result of the Sylvan/Viola unconformity. In addition to this, it has been determined that these paleokarst sinkholes are linked in formation to visually similar paleokarst sinkholes located in the Ellenburger Group in the Fort Worth Basin.

  19. Imaging 3D anisotropic upper mantle shear velocity structure of Southeast Asia using seismic waveform inversion

    Chong, J.; Yuan, H.; French, S. W.; Romanowicz, B. A.; Ni, S.

    2011-12-01

    Southeast Asia as a special region in the world which is seismically active and is surrounded by active tectonic belts, such as the Himalaya collision zone, western Pacific subduction zones and the Tianshan- Baikal tectonic belt. Seismic anisotropic tomography can shade light on the complex crust and upper mantle dynamics of this region, which is the subject of much debate. In this study, we applied full waveform time domain tomography to image 3D isotropic and anisotropic upper mantle shear velocity structure of Southeast Asia. Three component waveforms of teleseismic and far regional events (15 degree ≤ Δ≤ 165 degree) with magnitude ranges from Mw6.0 to Mw7.0 are collected from 91 permanent and 438 temporary broadband seismic stations in SE Asia. Wavepackets of both fundamental and overtone modes, filtered between 60 and 400 sec, are selected automatically according to the similarity between data and synthetic waveforms (Panning & Romanowicz, 2006). Wavepackets corresponding to event-station paths that sample the region considered are weighted according to path redundancy and signal to noise ratio. Higher modes and fundamental mode wavepackets are weighted separately in order to enhance the contribution of higher modes which are more sensitive to deeper structure compared to the fundamental mode. Synthetic waveforms and broadband sensitivity kernels are computed using normal mode asymptotic coupling theory (NACT, Li & Romanowicz, 1995). As a starting model, we consider a global anisotropic upper mantle shear velocity model based on waveform inversion using the Spectral Element Method (Lekic & Romanowicz, 2011), updated for more realistic crustal thickness (French et al., 2011) as our starting model, we correct waveforms for the effects of 3D structure outside of the region, and invert them for perturbations in the 3D structure of the target region only. We start with waveform inversion down to 60sec and after several iterations, we include shorter period

  20. 3-D seismic response of a base-isolated fast reactor

    This paper describes a 3-D response analysis methodology development and its application to a base-isolated fast breeder reactor (FBR) plant. At first, studies on application of a base-isolation system to an FBR plant were performed to identify a range of appropriate characteristics of the system. A response analysis method was developed based on mathematical models for the restoring force characteristics of several types of the systems. A series of shaking table tests using a small scale model was carried out to verify the analysis method. A good agreement was seen between the test and analysis results in terms of the horizontal and vertical responses. Parametric studies were then made to assess the effects of various factors which might be influential to the seismic response of the system. Moreover, the method was applied to evaluate three-dimensional response of the base-isolated FBR. (author)

  1. A 3D surface seismic pilot study at Olkiluoto, Finland. Aquisition and processing report

    Juhlin, C. (Uppsala University (SE)); Cosma, C. (Vibrometric Oy, Vantaa (FI))

    2007-08-15

    Posiva carries out R and D tasks related to spent nuclear fuel disposal in Finland. Works are currently performed in the Olkiluoto Island, in western Finland. Multidisciplinary engineering and geological investigations have been carried out since 1987. Site and rock characterization continued underground after 2004, in the ONKALO underground research facility. Posiva co-operated with Andra, France (Agence Nationale des Dechets Radioactifs) to purchase the design, acquisition and processing work needed to demonstrate the capability of 3D seismic techniques to image geological and structural features in crystalline rock. A 3D seismic pilot survey was carried out at the Olkiluoto site during seven days in June 2006. Data acquisition and processing were carried out as a Finnish-Swedish joint effort of Vibrometric and Uppsala University. The seismic survey covered 600 x 650 m area to the west of ONKALO underground premises. The single-template fixed array consisted of 270 active geophones on nine NW-SE lines. Geophone line interval was 60 m and station interval 24 m (30 channels on line). Sources (469 in total) were placed on seven NE-SW lines perpendicular to the receiver lines. The shot line interval was 100 m and the shot spacing 10 m (71 shots per line). The source was a time distributed Vibsist impact source (2000-2500 J/ impact), using a hydraulic rock breaker. The receivers (28 Hz geophones) were connected to a Sercel 408 UL seismograph. The coverage and signal quality were good. The array size was small compared to imaging depth, compared with conventional 3D works. The fold (CDP bin size 12 x 12 m) was highly variable (5->100), lower at the edges of area. Reflections are already seen in the processed receiver and shot gathers. The processing comprised time stacking (impact decoding), first arrival picking, resampling, refraction and residual static corrections, spectral equalisation, band-pass filtering, NMO and DMO, stacking. Static corrections, DMO and

  2. How an independent put inexpensive 3-D seismic to good use in New Mexico

    Nester, D.C. (Landmark/Concurrent Solutions, Houston, TX (US)); Emdsley, D. (Merrion Oil and Gas Corp., Farmington, NM (US))

    1992-03-23

    This paper reports that as major oil companies focus their attention offshore and overseas, independents in the U.S. continue to find and develop onshore reserves using their traditional strengths. Those strengths have been low overhead, nimble decisionmaking, and hard-won experience within a particular geologic region. Today many of these companies are emerging as even tougher competitors by applying 3-D seismic along with the multidisciplinary know-how and the interactive workstations needed to interpret it. The recent experience of Merrion Oil and Gas Corp., Farmington, N.M., offers a case in point. When oil prices collapsed in 1986, Merrion saw the chance to venture into exploration at low cost. Ever since, the company has devoted its resources to exploring for oil in the San Juan basin's Entrada sand dunes, a complex stratigraphic play found at 6,000 ft.

  3. A 3D surface seismic pilot study at Olkiluoto, Finland. Aquisition and processing report

    Posiva carries out R and D tasks related to spent nuclear fuel disposal in Finland. Works are currently performed in the Olkiluoto Island, in western Finland. Multidisciplinary engineering and geological investigations have been carried out since 1987. Site and rock characterization continued underground after 2004, in the ONKALO underground research facility. Posiva co-operated with Andra, France (Agence Nationale des Dechets Radioactifs) to purchase the design, acquisition and processing work needed to demonstrate the capability of 3D seismic techniques to image geological and structural features in crystalline rock. A 3D seismic pilot survey was carried out at the Olkiluoto site during seven days in June 2006. Data acquisition and processing were carried out as a Finnish-Swedish joint effort of Vibrometric and Uppsala University. The seismic survey covered 600 x 650 m area to the west of ONKALO underground premises. The single-template fixed array consisted of 270 active geophones on nine NW-SE lines. Geophone line interval was 60 m and station interval 24 m (30 channels on line). Sources (469 in total) were placed on seven NE-SW lines perpendicular to the receiver lines. The shot line interval was 100 m and the shot spacing 10 m (71 shots per line). The source was a time distributed Vibsist impact source (2000-2500 J/ impact), using a hydraulic rock breaker. The receivers (28 Hz geophones) were connected to a Sercel 408 UL seismograph. The coverage and signal quality were good. The array size was small compared to imaging depth, compared with conventional 3D works. The fold (CDP bin size 12 x 12 m) was highly variable (5->100), lower at the edges of area. Reflections are already seen in the processed receiver and shot gathers. The processing comprised time stacking (impact decoding), first arrival picking, resampling, refraction and residual static corrections, spectral equalisation, band-pass filtering, NMO and DMO, stacking. Static corrections, DMO and

  4. Delineation of Gulf of Mexico Miocene reservoirs with 3-D seismic data

    Wellborn, J.E. (Conoco Inc., Houston, TX (United States)); Brown, A.R.

    1991-03-01

    Seismic amplitude anomalies associated with Miocene plays in the Mobile area, offshore Alabama, are well documented and well drilled. Three-dimensional seismic data permit a much better understanding of these sandstone reservoirs than the 2-D data available over most prospects. In this paper Digicon's Mobile Phase 1 3-D data have been studied and the extent of two hydrocarbon-bearing sand bodies recognized on both vertical and horizontal sections. The first example shows a sand body interpreted as an offshore bar. The second shows a more complex reservoir geometry and is interpreted as a deltaic fan deposit. Both reservoirs are stratigraphically controlled. Horizon slices were constructed for each reservoir by amplitude extraction using Conoco's interactive interpretation system. The resultant contours defined the areal extent of the reservoirs. After successful gas wells were drilled into both features, pay thicknesses and reserve calculations were made by integrating the amplitudes on the horizon slices and the well information in preparation for production.

  5. Refining seismic parameters in low seismicity areas by 3D trenching: The Alhama de Murcia fault, SE Iberia

    Ferrater, Marta; Ortuño, Maria; Masana, Eulàlia; Pallàs, Raimon; Perea, Hector; Baize, Stephane; García-Meléndez, Eduardo; Martínez-Díaz, José J.; Echeverria, Anna; Rockwell, Thomas K.; Sharp, Warren D.; Medialdea, Alicia; Rhodes, Edward J.

    2016-06-01

    Three-dimensional paleoseismology in strike-slip faults with slip rates less than 1 mm per year involves a great methodological challenge. We adapted 3D trenching to track buried channels offset by the Alhama de Murcia seismogenic left-lateral strike-slip fault (SE Iberia). A fault net slip of 0.9 ± 0.1 mm/yr was determined using statistical analysis of piercing lines for one buried channel, whose age is constrained between 15.2 ± 1.1 ka and 21.9-22.3 cal BP. This value is larger and more accurate than the previously published slip rates for this fault. The minimum number of five paleo-earthquakes identified since the deposition of dated layers suggests a maximum average recurrence interval of approximately 5 ka. The combination of both seismic parameters yields a maximum slip per event between 5.3 and 6.3 m. We show that accurately planned trenching strategies and data processing may be key to obtaining robust paleoseismic parameters in low seismicity areas.

  6. Modeling the Coast Mountains Batholith, British Columbia, Canada with 3D Seismic Tomography

    Quinonez, S. M.; Olaya, J. C.; Miller, K. C.; Romero, R.; Velasco, A. A.; Harder, S. H.; Cerda, I.

    2011-12-01

    The Coast Mountains Batholith on the west coast of British Columbia, Canada comprises a series of granitic to tonalitic plutons; where felsic continental crust is generated from the subduction of mafic oceanic crust by partial melting and fractionation, leaving ultra-mafic roots. In July of 2009, a large controlled-source experiment was conducted along a 400km east - west transect from Bella Bella into central British Columbia. Student volunteers from multiple universities deployed 1,800 one-component and 200 three-component geophones plus 2400 Texan data recorders with 200-m spacing intervals and shot spacing at 30-km. The 18-point sources ranged from 160 to 1,000 kg of high explosive. The geoscience component of the NSF-funded Cyber-ShARE project at UTEP focuses on fusing models developed from different data sets to develop 3-D Earth models. Created in 2007, the Cyber-ShARE Center brings together experts in computer science, computational mathematics, education, earth science, and environmental science. We leverage the Cyber-ShARE work to implement an enhanced 3-D finite difference tomography approach for P-wave delays times (Hole, 1992) with a graphical user interface and visualization framework. In particular, to account for model sensitivity to picked P-wave arrival times, we use a model fusion approach (Ochoa et al., 2010) to generate a model with the lowest RMS residual that a combination of a set of Monte Carlo sample models. In order to make the seismic tomography process more interactive at many points, visualizations of model perturbation at each iteration will help to troubleshoot when a model is not converging to highlight where the RMS residual values are the highest to pinpoint where changes need to be made to achieve model convergence. Finally, a model of the upper mantle using 3-D P-wave tomography will be made to determine the location of these ultra-mafic roots.

  7. Full Waveform 3D Synthetic Seismic Algorithm for 1D Layered Anelastic Models

    Schwaiger, H. F.; Aldridge, D. F.; Haney, M. M.

    2007-12-01

    Numerical calculation of synthetic seismograms for 1D layered earth models remains a significant aspect of amplitude-offset investigations, surface wave studies, microseismic event location approaches, and reflection interpretation or inversion processes. Compared to 3D finite-difference algorithms, memory demand and execution time are greatly reduced, enabling rapid generation of seismic data within workstation or laptop computational environments. We have developed a frequency-wavenumber forward modeling algorithm adapted to realistic 1D geologic media, for the purpose of calculating seismograms accurately and efficiently. The earth model consists of N layers bounded by two halfspaces. Each layer/halfspace is a homogeneous and isotropic anelastic (attenuative and dispersive) solid, characterized by a rectangular relaxation spectrum of absorption mechanisms. Compressional and shear phase speeds and quality factors are specified at a particular reference frequency. Solution methodology involves 3D Fourier transforming the three coupled, second- order, integro-differential equations for particle displacements to the frequency-horizontal wavenumber domain. An analytic solution of the resulting ordinary differential system is obtained. Imposition of welded interface conditions (continuity of displacement and stress) at all interfaces, as well as radiation conditions in the two halfspaces, yields a system of 6(N+1) linear algebraic equations for the coefficients in the ODE solution. An optimized inverse 2D Fourier transform to the space domain gives the seismic wavefield on a horizontal plane. Finally, three-component seismograms are obtained by accumulating frequency spectra at designated receiver positions on this plane, followed by a 1D inverse FFT from angular frequency ω to time. Stress-free conditions may be applied at the top or bottom interfaces, and seismic waves are initiated by force or moment density sources. Examples reveal that including attenuation

  8. Interpretation of a 3D Seismic-Reflection Volume in the Basin and Range, Hawthorne, Nevada

    Louie, J. N.; Kell, A. M.; Pullammanappallil, S.; Oldow, J. S.; Sabin, A.; Lazaro, M.

    2009-12-01

    A collaborative effort by the Great Basin Center for Geothermal Energy at the University of Nevada, Reno, and Optim Inc. of Reno has interpreted a 3d seismic data set recorded by the U.S. Navy Geothermal Programs Office (GPO) at the Hawthorne Army Depot, Nevada. The 3d survey incorporated about 20 NNW-striking lines covering an area of approximately 3 by 10 km. The survey covered an alluvial area below the eastern flank of the Wassuk Range. In the reflection volume the most prominent events are interpreted to be the base of Quaternary alluvium, the Quaternary Wassuk Range-front normal fault zone, and sequences of intercalated Tertiary volcanic flows and sediments. Such a data set is rare in the Basin and Range. Our interpretation reveals structural and stratigraphic details that form a basis for rapid development of the geothermal-energy resources underlying the Depot. We interpret a map of the time-elevation of the Wassuk Range fault and its associated splays and basin-ward step faults. The range-front fault is the deepest, and its isochron map provides essentially a map of "economic basement" under the prospect area. There are three faults that are the most readily picked through vertical sections. The fault reflections show an uncertainty in the time-depth that we can interpret for them of 50 to 200 ms, due to the over-migrated appearance of the processing contractor’s prestack time-migrated data set. Proper assessment of velocities for mitigating the migration artifacts through prestack depth migration is not possible from this data set alone, as the offsets are not long enough for sufficiently deep velocity tomography. The three faults we interpreted appear as gradients in potential-field maps. In addition, the southern boundary of a major Tertiary graben may be seen within the volume as the northward termination of the strong reflections from older Tertiary volcanics. Using a transparent volume view across the survey gives a view of the volcanics in full

  9. Zonation of North Alex Mud Volcano Highlighted by 3-D Active and Passive Seismic Data

    Bialas, J.; Lefeldt, M. R.; Klaeschen, D.; Papenberg, C. A.; Brueckmann, W.

    2010-12-01

    The West Nile Delta forms part of the source of the large turbiditic Nile Deep Sea Fan. Since the late Miocene sediments have formed an up to 10 km thick pile, which includes about 1 - 3 km of Messinian evaporates. The sediment load of the overburden implies strong overpressures and salt-related tectonic deformation. Both are favourable for fluid migration towards the seafloor guided by the fractured margin. The western deltaic system, Rosetta branch, has formed an 80 km wide continental shelf. Here at 700 m water depth the mud volcano North Alex (NA) developed his circular bathymetric feature, which proved to be an active gas and mud-expelling structure. A 3-D high-resolution multichannel seismic survey (IFM-GEOMAR P-Cable system) was completed across the mud volcano. 3-D time migration provided a 3-D data cube with a 6.25 m grid. Vertical seismic sections did reveal a large set of faults located within the main mud volcano as well as surrounding the structure. Internal faults are mainly related to episodic mud expulsion processes and continuous gas and fluid production. Deep cutting external faults surround the structure in a half circle shape. Horizontal amplitude maps (time slices) of indicate recent activity of these faults even up to the seafloor. High gas saturation of the sediments is indicated by inverted reflection events. In the centre the gas front cuts into the seafloor reflection while it dips down with increasing radius. Only with the small grid resolution inward dipping reflections become visible, which form an upward opened concave reflector plane underlying the top gas front. The interpretation assumes an oval lens shaped body (conduit) saturated with gas at the top of the mud volcano. It provides the upper termination of the mud chimney. This separation is further supported by passive seismic observations. Distant earthquakes can stimulate long-period harmonic oscillations in mud volcanoes. Such oscillations are detectable with three

  10. Probabilistic Seismic Hazard Maps of Seattle, Washington, Including 3D Sedimentary Basin Effects and Rupture Directivity: Implications of 3D Random Velocity Variations (Invited)

    Frankel, A. D.; Stephenson, W. J.; Carver, D.; Odum, J.; Williams, R. A.; Rhea, S.

    2010-12-01

    We have produced probabilistic seismic hazard maps of Seattle for 1 Hz spectral acceleration, using over five hundred 3D finite-difference simulations of earthquakes on the Seattle fault, Southern Whidbey Island fault, and Cascadia subduction zone, as well as for random deep and shallow earthquakes at various locations. The 3D velocity model was validated by modeling the observed waveforms for the 2001 M6.8 Nisqually earthquake and several smaller events in the region. At these longer periods (≥ 1 sec) that are especially important to the response of buildings of ten stories or higher, seismic waves are strongly influenced by sedimentary basins and rupture directivity. We are investigating how random spatial variations in the 3D velocity model affect the simulated ground motions for M6.7 earthquakes on the Seattle fault. A fractal random variation of shear-wave velocity with a Von Karman correlation function produces spatial variations of peak ground velocity with multiple scale lengths. We find that a 3D velocity model with a 10% standard deviation in shear-wave velocity in the top 1.5 km and 5% standard deviation from 1.5-10 km depth produces variations in peak ground velocities of as much as a factor of two, relative to the case with no random variations. The model with random variations generally reduces the peak ground velocity of the forward rupture directivity pulse for sites near the fault where basin-edge focusing of S-waves occurs. It also tends to reduce the peak velocity of localized areas where basin surface waves are focused. However, the medium with random variations also causes small-scale amplification of ground motions over distances of a few kilometers. We are also evaluating alternative methods of characterizing the aleatory uncertainty in the probabilistic hazard calculations.

  11. 3D Seismic Velocity Structure in the Rupture Area of the 2010 Maule Mw=8.8 Earthquake

    Hicks, S. P.; Rietbrock, A.; Ryder, I. M.; Nippress, S.; Haberland, C. A.

    2011-12-01

    The 2010 Mw=8.8 Maule, Chile earthquake is one of the largest subduction zone earthquakes ever recorded. Up to now numerous co-seismic and some post-seismic slip models have been published based entirely on seismological, geodetic, or tsunami run-up heights, or combinations of these data. Most of these models use a simplified megathrust geometry derived mainly from global earthquake catalogues, and also simplified models of seismic parameters (e.g. shear modulus). By using arrival times for a vast number of aftershocks that have been recorded on a temporary seismic array, we present a new model for the slab geometry based on earthquake locations together with a new 3D seismic velocity model of the region, for both vp and vp/vs. We analyzed 3552 aftershocks that occurred between 18 March and 24 May 2011, recorded by the International Maule Aftershock Dataset (IMAD) seismic network. Event selection from a catalogue of automatically-determined events was based on 20 or more arrival times, from which at least 10 are S-wave observations. In total over 170,000 arrival times (~125,000 and 45,000 P and S wave arrival times respectively) are used for the tomographic reconstructions. Initially, events were relocated in a 2D velocity model based on a previously published model for the southern end of the rupture area (Haberland et al., 2009). Afterwards a staggered inversion scheme is implemented, starting with a 2D inversion followed by a coarse 3D and a subsequent fine 3D inversion. Based on our preliminary inversions we conclude that aftershock seismicity is mainly concentrated between 20 and 35 km depth along the subduction interface. A second band of seismicity between 40 and 50 km depth is also observed. Low seismic velocities and an increased vp/vs ratio characterize the marine forearc. The obtained velocity model will be discussed.

  12. 3D multicomponent seismic characterization of a clastic reservoir in the Middle Magdalena Valley Basin, Colombia

    Velasquez-Espejo, Antonio Jose

    The main goal of this research is to characterize the combined structural-stratigraphic trap of the Tenerife Field in the Middle Magdalena Valley Basin (MMVB), Colombia. For the first time in Colombia the structural and quantitative interpretation of modern three-dimensional multicomponent (3D-3C) seismic imaging enables a geometric description, a kinematic interpretation of the structural styles, and the facies distribution of the reservoir. A seismic petrophysics work-flow to better achieve the seismic well-tie. Edited and check-shot calibrated P-wave sonic logs were obtained and coefficients of the Gardner and Castagna equations were calibrated to match the density and shear-wave velocity depth trends for the basin. Seismic modeling was performed to evaluate the PP and PS seismic response of the reservoir interval (Mugrosa Formation). The structural interpretation methodology involves a 3D fault-correlation and horizon picking for both PP- and PS-PSTM data volumes. Geometric attributes such as coherence and curvature were used to enhance the structural discontinuities. The main unconformity of the Middle Eocene (MEU) was interpreted, and an attribute-assisted interpretation of the reservoir was conducted in detail. While P-wave data provided most of the structural interpretation, converted-wave data provide a better understanding of the faults. Traditionally, compressive thrust-propagation folds and tectonic inversion have been considered as the main mechanisms controlling the deformation in the MMVB. However, the new interpretation shown in this work provides a different structural concept that involves two major structural styles: 1. Under the MEU the Late Cretaceous and Early Paleocene deformation, dominated by east-verging thrust and partially inverted Mesozoic normal faults, is preserved. Associated folds exhibit a north-south strike, and their structural development is controlled by a long-lived structural element that dominates the area (the Infantas

  13. Comparative velocity structure of active Hawaiian volcanoes from 3-D onshore-offshore seismic tomography

    Park, J.; Morgan, J.K.; Zelt, C.A.; Okubo, P.G.; Peters, L.; Benesh, N.

    2007-01-01

    We present a 3-D P-wave velocity model of the combined subaerial and submarine portions of the southeastern part of the Island of Hawaii, based on first-arrival seismic tomography of marine airgun shots recorded by the onland seismic network. Our model shows that high-velocity materials (6.5-7.0??km/s) lie beneath Kilauea's summit, Koae fault zone, and the upper Southwest Rift Zone (SWRZ) and upper and middle East Rift Zone (ERZ), indicative of magma cumulates within the volcanic edifice. A separate high-velocity body of 6.5-6.9??km/s within Kilauea's lower ERZ and upper Puna Ridge suggests a distinct body of magma cumulates, possibly connected to the summit magma cumulates at depth. The two cumulate bodies within Kilauea's ERZ may have undergone separate ductile flow seaward, influencing the submarine morphology of Kilauea's south flank. Low velocities (5.0-6.3??km/s) seaward of Kilauea's Hilina fault zone, and along Mauna Loa's seaward facing Kao'iki fault zone, are attributed to thick piles of volcaniclastic sediments deposited on the submarine flanks. Loihi seamount shows high-velocity anomalies beneath the summit and along the rift zones, similar to the interpreted magma cumulates below Mauna Loa and Kilauea volcanoes, and a low-velocity anomaly beneath the oceanic crust, probably indicative of melt within the upper mantle. Around Kilauea's submarine flank, a high-velocity anomaly beneath the outer bench suggests the presence of an ancient seamount that may obstruct outward spreading of the flank. Mauna Loa's southeast flank is also marked by a large, anomalously high-velocity feature (7.0-7.4??km/s), interpreted to define an inactive, buried volcanic rift zone, which might provide a new explanation for the westward migration of Mauna Loa's current SWRZ and the growth of Kilauea's SWRZ. ?? 2007 Elsevier B.V. All rights reserved.

  14. Borehole seismic monitoring of CO2 storage within a saline aquifer at Ketzin, Germany

    J. Götz

    2014-01-01

    This thesis is about borehole seismic monitoring of CO2 storage within a saline aquifer at Ketzin, Germany. CO2 storage is part of the process ’Carbon dioxide Capture and Storage (CCS)’. As a greenhouse gas, CO2 contributes to the global warming, therefore efforts are made to slow down the increase of CO2 concentration in the atmosphere. CCS is considered because ”fossil fuels are the dominant form of energy utilised in the world (86 %) and account for 75% of current anthropoge...

  15. Reconstruction of allochthonous salt emplacement from 3-D seismic reflection data, northern Gulf of Mexico

    Walters, R.D. (Univ. of Texas, Austin (United States))

    1993-05-01

    Analysis of a 110 mi[sup 2] (284 km[sup 2]) three-dimensional (3-D) seismic survey located at the northern Gulf of Mexico continental shelf edge documents the emplacement history of an allochthonous salt structure. A listric, counter-regional growth fault bounds the updip salt edge and apparently soles into a detachment surface from which salt was evacuated. The counter-regional fault system served as the feeder stock for the dome. The current salt shape is an asymmetric, elongated wedge with a diameter of 20,000 ft (6.1 km) and maximum thickness of 13,000 ft (4.0 km). A steep fault/salt contact bounded by small, oval- shaped withdrawal subbasins on the landward side contrasts with a shallow-dipping basinward salt/sediment contact. A relatively thin sediment cover onlaps the shallow basinward salt flank. Regional seismic lines support the presence of a detachment surface in the area apparently separating Upper Cretaceous to lower Tertiary( ) sediments from upper Miocene (7.0--5.4 Ma) and younger sediments. During the first stage, an allochthonous salt sheet was emplaced during the hiatus and then segmented. From the middle to late Pliocene (4.0--2.2 Ma), the salt structure evolved by downbuilding, remaining close to the ocean floor surface and covered by only a thin sediment veneer. After the beginning of the Illinoian glacial stage (0.85 Ma), the deep source salt layer was depleted and the dome was buried by up to 1,700 ft (520 m) of sediment during the third stage. Seismic amplitude anomalies associated with structural disconformities indicate a possible salt evacuation surface or salt weld along the deep feeder stock. Geohistory diagrams indicate extremely rapid local subsidence in the withdrawal basin, which contains up to 12,000 ft (3.6 km) of Pleistocene sediment. Such acceleration subsidence, in conjunction with the fault/salt geometry, contributed to the development of hydrocarbon reservoirs near the dome flanks. 69 refs., 17 figs., 1 tab.

  16. Research on 3-D base isolation system applied to new power reactor 3-D seismic isolation device with rolling seal type air spring: Pt.2

    A three dimensional seismic base isolation device was developed for heavy structures and buildings such as nuclear power reactor buildings. The device realizes 3-D isolation by combining a LRB (laminated rubber bearing) for horizontal isolation with an air spring for vertical isolation in series. In this study, scale models of the 3-D base isolation device were made and were tested to examine the dynamic properties and ultimate strengths of the device. The performance of the device under earthquake excitation was examined through shaking table tests of 1/7 scale models. As the results, it was confirmed that the device worked smoothly under the horizontal and vertical excitations, and that the theoretical formulae of the orifice damping could explain the test results. The high-pressure air springs of trial production were forced to burst to find out which factor influenced ultimate strength. It was confirmed from results of the burst test that the strength of the air spring depended upon the diameter of rolling part of the bellows and the number of layers of the reinforcing fibers. Judging from the results of the shaking table test and the burst test, the developed 3-D base isolation device was applicable to a nuclear power plant building. (authors)

  17. 3D Seismic Reflection Data: Has the Geological Hubble Retained Its Focus?

    Jackson, Christopher

    2016-04-01

    In their seminal paper in 2002, Joe Cartwright and Mads Huuse referred to 3D seismic reflection data as the 'Geological Hubble', illustrating how these data had the potential to revolutionise our understanding of the genesis and evolution of sedimentary basins. 14 years on, I will here outline just some of the key recent advances made in our understanding of basin structure and stratigraphy, focusing on: (i) the intrusion and extrusion of igneous rocks; (ii) salt tectonics, with particular emphasis on intrasalt structure and the kinematics and mechanics of diapirism; (iii) the geometry and growth of normal faults; and (iv) the structure and emplacement of mass-transport complexes (MTCs). I will stress that future advances at least partly relies on hydrocarbon exploration companies and government agencies continuing to make their data freely available via easy-to-access data portals. I will issue a clarion call to academics, stressing that 'geodynamicists', sedimentologists, structural geologists and geomorphologists, amongst others, can benefit from utilising what I believe are currently an underused data type.

  18. Effect of 3-D viscoelastic structure on post-seismic relaxation from the 2004 M = 9.2 Sumatra earthquake

    Pollitz, F.; Banerjee, P.; Grijalva, K.; Nagarajan, B.; Burgmann, R.

    2008-01-01

    The 2004 M=9.2 Sumatra-Andaman earthquake profoundly altered the state of stress in a large volume surrounding the ???1400 km long rupture. Induced mantle flow fields and coupled surface deformation are sensitive to the 3-D rheology structure. To predict the post-seismic motions from this earthquake, relaxation of a 3-D spherical viscoelastic earth model is simulated using the theory of coupled normal modes. The quasi-static deformation basis set and solution on the 3-D model is constructed using: a spherically stratified viscoelastic earth model with a linear stress-strain relation; an aspherical perturbation in viscoelastic structure; a 'static'mode basis set consisting of Earth's spheroidal and toroidal free oscillations; a "viscoelastic" mode basis set; and interaction kernels that describe the coupling among viscoelastic and static modes. Application to the 2004 Sumatra-Andaman earthquake illustrates the profound modification of the post-seismic flow field at depth by a slab structure and similarly large effects on the near-field post-seismic deformation field at Earth's surface. Comparison with post-seismic GPS observations illustrates the extent to which viscoelastic relaxation contributes to the regional post-seismic deformation. ?? Journal compilation ?? 2008 RAS.

  19. 3-D Seismic Images of Mud Volcano North Alex, West-Nile Delta, Egypt

    Bialas, Joerg; Klaeschen, Dirk; Papenberg, Cord; Gehrmann, Romina; Sommer, Malte

    2010-05-01

    Mud volcanoes within shelf areas are the bathymetric expression of mobilized overpressured sediments causing a feature of possible instability within the slope. Such a scene is given in the West-Nile Delta offshore Alexandria, Egypt at 700 m water depth, ,which was studied during a RWE Dea funded research project. The West Nile Delta forms part of the source of the large turbiditic Nile Deep Sea Fan. Since the late Miocene sediments have formed an up to 10 km thick pile, which includes about 1 - 3 km of Messinian evaporates. The sediment load of the overburden implies strong overpressures and salt-related tectonic deformation. Both are favourable for fluid migration towards the seafloor guided by the fractured margin. Deep-cutting channel systems like the Rosetta channel characterize the continental slope. Bathymetric expressions of slides and numerous mud volcanoes in the area are expressions of active processes, which contribute to the ongoing modification of the slope. The western deltaic system, Rosetta branch, has formed an 80 km wide continental shelf. Here at 700 m water depth the mud volcano North Alex developed his circular bathymetric feature, which proved to be an active gas and mud-expelling structure. A grid of 2-D seismic profiles did reveal a large set of faults located within the main mud volcano as well as surrounding the structure. Internal faults are mainly related to episodic mud expulsion processes and continuous gas and fluid production. Deep cutting external faults surround the structure in a half circle shape. They can be tracked up to the seafloor indicating ongoing tectonic activity of the slope area. A recently build 3-D acquisition system (funded by RWE Dea) suitable for mid-size research vessels was applied to collect an active seismic cube of the mud volcano. Based on the P-Cable design 11 parallel streamers (each 12.5 m long with 1.5 m group interval) were used to record shots of a single 210 cinch GI airgun. Based on GPS positions of

  20. Evaluation of the 3D high resolution seismic method at the Tournemire site around the IPSN experimental station

    The IPSN experimental station of Tournemire is localized at a 200 m depth inside an abandoned railway tunnel dug in a Jurassic clayey formation. The a priori knowledge of the existing geologic structures of the clayey formations allows to test the reliability of the 3D high resolution seismic survey technique and its capability to detect these structures and discontinuities. This test study is reported in this technical note. It comprises several steps: a bibliographic synthesis and a state-of-the-art of the 3D seismic survey technique, the construction of a velocity model for the different strata of the site, a simulation of the possible seismic response of these strata with respect to the velocities chosen, the processing of the data and finally their interpretation. (J.S.)

  1. 3D seismic analysis of the Collyhurst Sandstone: implications for CO2 sequestration in the East Irish Sea Basin

    Gamboa, Davide; Williams, John; Kirk, Karen; Gent, Christopher; Bentham, Michelle; Fellgett, Mark; Schofield, David

    2016-04-01

    Carbon Capture and Storage (CCS) is a vital technology towards low-carbon energy resources and the mitigation of global warming trends induced by rising CO2 levels in the atmosphere. The East Irish Sea Basin (EISB) is a key area for CCS in the western UK, having high CO2 storage potentials in explored hydrocarbon fields and in saline aquifers within the Permo-Triassic Sherwood Sandstone Formation. However, the theoretical storage potential of the EISB could be poorly estimated as the reservoir-prone Lower Permian formations are not considered in detail by current estimations. This work aims to fill this gap, focusing on the characterisation of the Lower Permian Collyhurst Sandstone Formation as a viable storage unit. The potential for CO2 storage is estimated as the total volume/area of suitable closures that are isolated by structural traps, occurring at depths suitable for CO2 injection and containment (>800m). Detailed structural and stratigraphic interpretations were made using 3D seismic data to assess the storage potential of the Collyhurst Sandstone Formation in the southern EISB. The basin strata is compartmentalised by numerous N-S trending faults. A higher degree of compartmentalisation occurs within regional anticlines where elongated tilted blocks are observed, bound by predominantly west-dipping faults that induce a variable offset of the Collyhurst Sandstone strata. Contrastingly, higher lateral continuity of this formation is observed within graben basins were faults are less frequent and with minor offset, thus potentially creating larger storage closures. Fault dip orientation in the grabens is variable, with west and east dipping faults occurring as a function of large east-dipping listric faults. This study was complemented by the stress modelling of the interpreted faults in order to assess the risk of CO2 leakage. Analysis of borehole breakouts observed in four approximately vertical wells in the EISB suggest a maximum horizontal stress

  2. Seismic Observation in Deep Boreholes and Its Applications - Workshop Proceedings, Niigata Institute of Technology, Kashiwazaki, Japan

    4 was only 70% that of Unit 2 at the same site. Given these circumstances, JNES initiated the 'Observation and Evaluation Study of Ground Motion Amplification' project by drilling a three-kilometer deep borehole on the premises of the Niigata Institute of Technology, which is located near the Kashiwazaki site, and proposed a series of workshops related to deep underground seismic observation and ground motion evaluation to the Seismic Subgroup of the OECD/NEA/IAGE Group at the April 2010 meeting. The first was held from 24-26 November 2010 as part of the first Kashiwazaki International Symposium on seismic safety, and the second was held on 7 to 9 November 2012. In the second WS, 36 papers were presented by the participants from eight countries including two international organizations, and discussed in three sessions (i.e. observation technology, evaluation of the observed seismic motion and the multipurpose use). Regarding the observation technology session, useful lessons-learned in probe development, setup and maintenance under the challenging conditions posed by great depth were described. This information from SAFORD and Kashiwazaki was thought to be particularly valuable for the planning and operation of similar facilities. As for the seismic observations from a deep borehole, it was identified that such observations are very effective for investigation of the earthquake generating process and are important for detailed understanding of the three-dimensional underground structure. There is not yet much experience with observation and application of a deep borehole, and therefore future developments and achievements are expected. The importance of simple ground motion evaluation technology combined with geophysical exploration was also acknowledged. Examples of multipurpose utilization and the advantage of seismic observations in deep boreholes were discussed. Multipurpose use was discussed not only for seismic design and evaluation of nuclear installations

  3. Potential Geophysical Field Transformations and Combined 3D Modelling for Estimation the Seismic Site Effects on Example of Israel

    Eppelbaum, Lev; Meirova, Tatiana

    2015-04-01

    It is well-known that the local seismic site effects may have a significant contribution to the intensity of damage and destruction (e.g., Hough et al., 1990; Regnier et al., 2000; Bonnefoy-Claudet et al., 2006; Haase et al., 2010). The thicknesses of sediments, which play a large role in amplification, usually are derived from seismic velocities. At the same time, thickness of sediments may be determined (or defined) on the basis of 3D combined gravity-magnetic modeling joined with available geological materials, seismic data and borehole section examination. Final result of such investigation is a 3D physical-geological model (PGM) reflecting main geological peculiarities of the area under study. Such a combined study needs in application of a reliable 3D mathematical algorithm of computation together with advanced methodology of 3D modeling. For this analysis the developed GSFC software was selected. The GSFC (Geological Space Field Calculation) program was developed for solving a direct 3-D gravity and magnetic prospecting problem under complex geological conditions (Khesin et al., 1996; Eppelbaum and Khesin, 2004). This program has been designed for computing the field of Δg (Bouguer, free-air or observed value anomalies), ΔZ, ΔX, ΔY , ΔT , as well as second derivatives of the gravitational potential under conditions of rugged relief and inclined magnetization. The geological space can be approximated by (1) three-dimensional, (2) semi-infinite bodies and (3) those infinite along the strike closed, L.H. non-closed, R.H. on-closed and open). Geological bodies are approximated by horizontal polygonal prisms. The program has the following main advantages (besides abovementioned ones): (1) Simultaneous computing of gravity and magnetic fields; (2) Description of the terrain relief by irregularly placed characteristic points; (3) Computation of the effect of the earth-air boundary by the method of selection directly in the process of interpretation; (4

  4. New insights into the earliest Quaternary environments in the Central North Sea from 3D seismic

    Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

    2014-05-01

    In the past the transition between an unconformable surface in the south to a conformable horizon towards the north has made identification and mapping the base-Quaternary in the central North Sea difficult (Sejrup et al 1991; Gatliff et al 1994). However recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) has allowed greater confidence in the correlation to the region 3D seismic datasets and thus has allowed the base-Quaternary to be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The revised base-Quaternary surface reaches a depth of 1248 ms TWT with an elongate basin shape which is significantly deeper than the traditionally mapped surface. Using RMS amplitudes and other seismic attributes the revised base-Quaternary has been investigated along the horizon and in time slice to interpret the environments of the earliest Quaternary prior to the onset of glaciation. Combined with analysis of aligned elongate furrows over 10 km long, 100 m wide and 100 m deep suggest a deep marine environment in an almost enclosed basin with persistent strong NW-SE bottom currents in the deepest parts. Pockmarks were formed by the escape of shallow gas on the sides of a small delta in the eastern part of the basin. The progradation of large deltas from both the north and south into the basin make up the majority of the deposition of sediment into the basin. Key Words: base-Quaternary; seismic interpretation; paleoenvironments References: Gatliff, R.W, Richards, P.C, Smith, K, Graham, C.C, McCormac, M, Smith, N.J.P, Long, D, Cameron, T.D.J, Evans, D, Stevenson, A.G, Bulat, J, Ritchie, J.D, (1994) 'United Kingdom offshore regional

  5. 3D VSP imaging in the Deepwater GOM

    Hornby, B. E.

    2005-05-01

    Seismic imaging challenges in the Deepwater GOM include surface and sediment related multiples and issues arising from complicated salt bodies. Frequently, wells encounter geologic complexity not resolved on conventional surface seismic section. To help address these challenges BP has been acquiring 3D VSP (Vertical Seismic Profile) surveys in the Deepwater GOM. The procedure involves placing an array of seismic sensors in the borehole and acquiring a 3D seismic dataset with a surface seismic gunboat that fires airguns in a spiral pattern around the wellbore. Placing the seismic geophones in the borehole provides a higher resolution and more accurate image near the borehole, as well as other advantages relating to the unique position of the sensors relative to complex structures. Technical objectives are to complement surface seismic with improved resolution (~2X seismic), better high dip structure definition (e.g. salt flanks) and to fill in "imaging holes" in complex sub-salt plays where surface seismic is blind. Business drivers for this effort are to reduce risk in well placement, improved reserve calculation and understanding compartmentalization and stratigraphic variation. To date, BP has acquired 3D VSP surveys in ten wells in the DW GOM. The initial results are encouraging and show both improved resolution and structural images in complex sub-salt plays where the surface seismic is blind. In conjunction with this effort BP has influenced both contractor borehole seismic tool design and developed methods to enable the 3D VSP surveys to be conducted offline thereby avoiding the high daily rig costs associated with a Deepwater drilling rig.

  6. Goal-Oriented Self-Adaptive hp Finite Element Simulation of 3D DC Borehole Resistivity Simulations

    Calo, Victor M.

    2011-05-14

    In this paper we present a goal-oriented self-adaptive hp Finite Element Method (hp-FEM) with shared data structures and a parallel multi-frontal direct solver. The algorithm automatically generates (without any user interaction) a sequence of meshes delivering exponential convergence of a prescribed quantity of interest with respect to the number of degrees of freedom. The sequence of meshes is generated from a given initial mesh, by performing h (breaking elements into smaller elements), p (adjusting polynomial orders of approximation) or hp (both) refinements on the finite elements. The new parallel implementation utilizes a computational mesh shared between multiple processors. All computational algorithms, including automatic hp goal-oriented adaptivity and the solver work fully in parallel. We describe the parallel self-adaptive hp-FEM algorithm with shared computational domain, as well as its efficiency measurements. We apply the methodology described to the three-dimensional simulation of the borehole resistivity measurement of direct current through casing in the presence of invasion.

  7. Construction of System for Seismic Observation in Deep Borehole (SODB) - Overview and Achievement Status of the Project

    The seismic responses of each unit at the Kashiwazaki-Kariwa NPP differed greatly during the 2007 Niigata-ken Chuetsu-oki Earthquake; the deep sedimentary structure around the site greatly affected these differences. To clarify underground structure and to evaluate ground motion amplification and attenuation effects more accurately in accordance with deep sedimentary structure, JNES initiated the SODB project. Deployment of a vertical seismometer array in a 3000-meter deep borehole was completed in June 2012 on the premises of NIIT. Horizontal arrays were also placed on the ground surface. Experiences and achievements in the JNES project were introduced, including development of seismic observation technology in deep boreholes, site amplification measurements from logging data, application of borehole observation data to maintenance of nuclear power plant safety, and so on. Afterwards, the relationships of other presentations in this WS, were explained. (authors)

  8. Delineation of tunnel valley across the North Sea coastline, Denmark based on reflection seismic data, boreholes, TEM and Schlumberger soundings

    Andersen, Theis Raaschou; Jørgensen, Flemming; Christensen, Steen

    2016-01-01

    on- and offshore 2D seismic data, TEM (Transient Electro-Magnetic) soundings, Schlumberger soundings, and boreholes. The valleys are observed as discrete incisions with three overall orientations: SSE – NNW, ESE – WNW, and SSW – NNE. They have depths between 75 and 185 m, widths up to 1.8 km, and...

  9. High-resolution 3D seismic data characterize fluid flow systems in the SW Barents Sea

    Bünz, Stefan; Mienert, Jürgen; Rajan, Anupama

    2010-05-01

    The flow of fluids through marine sediments is one of the most dominant and pervasive processes in continental margins. These processes control the evolution of a sedimentary basin and its seafloor environment, and have implications for hydrocarbon exploration and seabed ecosystems. Many seep sites at the seafloor are associated with large but complex faunal communities that have received significant attention in recent years. However, there is a need for a better understanding of the driving mechanism of fluid flow in various geological settings, the accumulation of fluids in the subsurface and their focused flow through conduits and/or faults to the seabed. The Barents Sea is a large hydrocarbon-prone basin of the Norwegian Arctic region. A significant portion of the hydrocarbons has leaked or migrated into the shallow subsurface and is now trapped in gas-hydrate and shallow-gas reservoirs. Furthermore, there are few places in the Barents Sea, where methane gas is leaking from the seafloor into the oceanosphere. Accumulations of free gas in the shallow subsurface are considered a geohazard. They constitute a risk for safe drilling operations and they may pose a threat to global climate if the seal that is trapping them is breached. P-Cable 3D high-resolution seismic data from the Ringvassøya Fault Complex and the Polheim Sub-Platform provide new and detailed insight into fluid flow controls and accumulation mechanisms. The data shows a wide variety of fluid flow features, mostly in the form of pockmarks, bright spots, wipe-out zones or vertical zones of disturbed reflectivity. Fluids migrate by both diapiric mechanism and channelized along sedimentary layers. Glacigenic sediments generally form a strong boundary for fluid flow in the very shallow section. However, we can recognize pockmarks not only at the seafloor but also at one subsurface layer approximately 50 m below sea floor indicating a former venting period in the SW Barents Sea. At few locations high

  10. Characterization of gas hydrate distribution using conventional 3D seismic data in the Pearl River Mouth Basin, South China Sea

    Wang, Xiujuan; Qiang, Jin; Collett, Timothy S.; Shi, Hesheng; Yang, Shengxiong; Yan, Chengzhi; Li, Yuanping; Wang, Zhenzhen; Chen, Duanxin

    2016-01-01

    A new 3D seismic reflection data volume acquired in 2012 has allowed for the detailed mapping and characterization of gas hydrate distribution in the Pearl River Mouth Basin in the South China Sea. Previous studies of core and logging data showed that gas hydrate occurrence at high concentrations is controlled by the presence of relatively coarse-grained sediment and the upward migration of thermogenic gas from the deeper sediment section into the overlying gas hydrate stability zone (BGHSZ); however, the spatial distribution of the gas hydrate remains poorly defined. We used a constrained sparse spike inversion technique to generate acoustic-impedance images of the hydrate-bearing sedimentary section from the newly acquired 3D seismic data volume. High-amplitude reflections just above the bottom-simulating reflectors (BSRs) were interpreted to be associated with the accumulation of gas hydrate with elevated saturations. Enhanced seismic reflections below the BSRs were interpreted to indicate the presence of free gas. The base of the BGHSZ was established using the occurrence of BSRs. In areas absent of well-developed BSRs, the BGHSZ was calculated from a model using the inverted P-wave velocity and subsurface temperature data. Seismic attributes were also extracted along the BGHSZ that indicate variations reservoir properties and inferred hydrocarbon accumulations at each site. Gas hydrate saturations estimated from the inversion of acoustic impedance of conventional 3D seismic data, along with well-log-derived rock-physics models were also used to estimate gas hydrate saturations. Our analysis determined that the gas hydrate petroleum system varies significantly across the Pearl River Mouth Basin and that variability in sedimentary properties as a product of depositional processes and the upward migration of gas from deeper thermogenic sources control the distribution of gas hydrates in this basin.

  11. Exploring anisotropic seismic property of the seismogenic plate boundary in the Nankai Trough using a seafloor borehole observatory

    Araki, E.; Kimura, T.; Kodaira, S.; Miura, S.; Takaesu, M.; Takahashi, N.; Nakano, M.; Kaneda, Y.

    2014-12-01

    Stress state in the vicinity of a seismogenic fault would be a key parameter governing its fault dynamics. Stress analysis in a borehole such as breakout may give stress information, but drilling seismogenic fault at depth is still challenging and it is even more difficult to perform repeated stress measurements for temporal evolution of stress state. Here we consider applying seismic anisotropy as an index of stress state and by observing its temporal change to identify change of stress around the seismogenic fault. In this study, we explored techniques to assess seismic anisotropy in the Nankai Trough accretionary prism, using a borehole seismometer deployed in IODP borehole C0002G, which is located just above the Tonankai earthquake fault. The borehole seismometer is situated at about 900 m below 1966 m deep seafloor, and is operational since January 2013 when the observatory was connected to DONET seafloor cable network. We developed a technique to analyze seismic anisotropy on converted S-wave from microseismic noise records and applied the technique on the borehole seismometer records, by which we expect to evaluate temporal change of anisotropy continuously. We obtained anisotropy of a few percent. We further evaluated depth dependency of anisotropy direction and obtained the difference between the uppermost sedimentary basin and accretionary prism near the plate boundary. We also performed airgun array shooting around the borehole in November 2013 to check validity of the anisotropy result. We applied two different analysis on the airgun records, the one was P-wave seismic anisotropy from the travel time, and the other was S-wave anisotropy using converted S-wave from airgun P-wave. Preliminary results from these analysis were consistent with the microseismic noise analysis. Repeated airgun shooting is planned at the interval of a year or so to evaluate our ability to detect its temporal change.

  12. Microearthquake Observations in a 7-level Vertical Seismic Array in the TCDP Borehole, Taiwan

    Lin, Y.; Wu, H.; Ma, K.; Oye, V.; Tanaka, H.

    2007-12-01

    In order to obtain in-situ information on slip zones of the 1999 Chi-Chi earthquake, the Taiwan Chelungpu-fault drilling project (TCDP) drilled two vertical boreholes (A, B) and a branch hole (C) through the fault where a displacement of 12 m had occurred. The TCDP hole A is 2 km deep, and a slip zone was identified at a depth of 1111 m. Hole B (with side track, hole C) is 1.3 km deep with an identified slip zone at 1138 m. In July 2006, a 7- level vertical borehole seismic array (TCDP BHS) was installed in hole A covering a depth from 946 m to 1274 m with 50- 60 m depth intervals. For this layout, three seismometers were placed in the hanging wall and footwall, respectively. The forth one is located at the depth of 1110.28 m, close to the identified slip zone. Microearthquakes with magnitude down to -0.5 were detected by the TCDP BHS. A temporary seismic array with 10 short period seismometers around the TCDP drill site was also installed to incorporate with the TCDP BHS for the precise locations of the microearthquakes. A real-time location software (MIMO) (Oye and Roth, 2003) was used to automatically determine P- and S-wave onset times, incidence and azimuth angles and locations of the microearthquakes. Regardless of the large co-seismic slip of 12 m at the drill site during the 1999 Chi-Chi earthquake, our preliminary studies do not show any close-by seismicity near the drill site after almost 8 years since the large earthquake happened. The microearthquakes clustered at a depth of 8-10 km, where the 30 degree dipping of the Chelungpu thrust fault becomes flat to a decollement of the Taiwan fold-and-thrust tectonic structure. As a continuous GPS survey did not observe post-slip at the large slip region, and as no seismicity was observed near the drill site, we suggest that the thrust belt above the decollement during the interseismic period seems to be locked. A Fluid Injection Test (FIT), pumping high pressure fluid into hole B and C with hole A as

  13. Integrated approach to 3-D seismic acquisition geometry analysis: emphasizing the influence of the inhomogeneous subsurface

    van Veldhuizen, E.J.

    2006-01-01

    The seismic reflection method for imaging of the earth's interior is an essential part of the exploration and exploitation of hydrocarbon resources. A seismic survey should be designed such that the acquired data leads to a sufficiently accurate subsurface image. The survey geometry analysis method

  14. tomo3d: a new 3-D joint refraction and reflection travel-time tomography code for active-source seismic data

    Meléndez, A.; Korenaga, J.; Sallares, V.; Ranero, C. R.

    2012-12-01

    We present the development state of tomo3d, a code for three-dimensional refraction and reflection travel-time tomography of wide-angle seismic data based on the previous two-dimensional version of the code, tomo2d. The core of both forward and inverse problems is inherited from the 2-D version. The ray tracing is performed by a hybrid method combining the graph and bending methods. The graph method finds an ordered array of discrete model nodes, which satisfies Fermat's principle, that is, whose corresponding travel time is a global minimum within the space of discrete nodal connections. The bending method is then applied to produce a more accurate ray path by using the nodes as support points for an interpolation with beta-splines. Travel time tomography is formulated as an iterative linearized inversion, and each step is solved using an LSQR algorithm. In order to avoid the singularity of the sensitivity kernel and to reduce the instability of inversion, regularization parameters are introduced in the inversion in the form of smoothing and damping constraints. Velocity models are built as 3-D meshes, and velocity values at intermediate locations are obtained by trilinear interpolation within the corresponding pseudo-cubic cell. Meshes are sheared to account for topographic relief. A floating reflector is represented by a 2-D grid, and depths at intermediate locations are calculated by bilinear interpolation within the corresponding square cell. The trade-off between the resolution of the final model and the associated computational cost is controlled by the relation between the selected forward star for the graph method (i.e. the number of nodes that each node considers as its neighbors) and the refinement of the velocity mesh. Including reflected phases is advantageous because it provides a better coverage and allows us to define the geometry of those geological interfaces with velocity contrasts sharp enough to be observed on record sections. The code also

  15. Improvement of high resolution borehole seismics. Part 1: Development of processing methods for VSP surveys. Part 2: Piezoelectric signal transmitter for seismic measurements

    The purpose of the high resolution borehole seismics project has been to improve the reliability and resolution of seismic methods in the particular environment of nuclear waste repository sites. The results obtained, especially the data processing and interpretation methods developed, are applicable also to other geophysical methods (e.g. Georadar). The goals of the seismic development project have been: the development of processing and interpretation techniques for mapping fractured zones, and the design and construction of a seismic source complying with the requirements of repository site characterization programs. Because these two aspects of the work are very different in nature, we have structured the report as two self contained parts. Part 1 describes the development of interpretive techniques. We have used for demonstrating the effect of different methods a VSP data set collected at the SCV site during Stage 1 of the project. Five techniques have been studied: FK-filtering, three versions of Tau-p filtering and a new technique that we have developed lately, Image Space filtering. Part 2 refers to the construction of the piezoelectric source. Earlier results obtained over short distances with low energy piezoelectric transmitters let us believe that the same principle could be applied for seismic signal transmitters, if solutions for higher energy and lower frequency output were found. The instrument which we have constructed is a cylindrical unit which can be placed in a borehole and is able to produce a radial strain when excited axially. The minimum borehole diameter is 56 mm. (au)

  16. Simulation of CO2 distribution pattern in an underground CO2 injection projected calibrated by 3D seismics

    In the ongoing aquifer CO2 disposal project in the Sleipner license (North Sea), underground CO2 is being monitored by time-lapse seismic. The CO2 is being injected close to the base of a high permeable, highly porous sand unit, the Utsira Sand. In an iterative process between seismic surveys and reservoir simulations, a reservoir model featuring the major controlling heterogeneities has been developed. Well-data and seismic data prior to injection shows that the sand is divided by nearly horizontal, discontinuous shales. >From the 3-D seismic image after three years of injection, strong reflectors can be interpreted as CO2 accumulations identifying the major shale layers that control the vertical migration of CQ from the injection point to the top of the formation. By modelling this flow in reservoir simulations, it can be inferred that the CO2 is transported in distinct columns between the shales rather than as dispersed bubbles over a large area. Improvement of the geological model increases the confidence of predictions based on simulation of the long-time fate Of CO2. A possible natural aquifer flow can have a pronounced effect on the location Of CO2 accumulations due to the relatively flat topography of the trapping shales. This effect has been quantified by simulation and this phenomenon was used to adjust the localisation of the CO2 bubbles to better fir the seismic images

  17. 2D and 3D numerical modeling of seismic waves from explosion sources

    Over the last decade, nonlinear and linear 2D axisymmetric finite difference codes have been used in conjunction with far-field seismic Green's functions to simulate seismic waves from a variety of sources. In this paper we briefly review some of the results and conclusions that have resulted from numerical simulations and explosion modeling in support of treaty verification research at S-CUBED in the last decade. We then describe in more detail the results from two recent projects. Our goal is to provide a flavor for the kinds of problems that can be examined with numerical methods for modeling excitation of seismic waves from explosions. Two classes of problems have been addressed; nonlinear and linear near-source interactions. In both classes of problems displacements and tractions are saved on a closed surface in the linear region and the representation theorem is used to propagate the seismic waves to the far-field

  18. Seismic ground motion amplification in a 3D sedimentary basin: the effect of the vertical velocity gradient

    Ground motion amplification in sedimentary basins has been observed in some moderate or large earthquakes, such as the 1994 Northridge and 1999 Chi-Chi event. Many numerical studies with simplified 2D models have shown significant effects of the vertical velocity gradient of sediment on basin amplification. However, we need to consider a more realistic 3D model and solve wave equations with 3D numerical methods in order to improve our understanding of basin amplification. In this study, we extend a 2D pseudospectral and finite difference hybrid method to a 3D case and investigate the effects of the vertical velocity gradient for a 3D basin model. Numerical simulations were performed for four basin models with increasing vertical velocity gradients on a PC cluster using 64 processors for 67 108 864 discretized grids. The results show that the vertical velocity gradient enhances basin amplification through strong secondary surface waves and basin trapped waves. The 3D geometry of the basin causes a wave-front focusing effect that contributes significantly to a localized strong amplification with the maximum peak ground velocity in the basin. The results of this study suggest that it is important to consider the detailed properties of sedimentary basins in seismic ground motion studies. (paper)

  19. Rupture process for micro-earthquakes inferred from borehole seismic recordings

    Taira, Taka'aki; Dreger, Douglas S.; Nadeau, Robert M.

    2015-09-01

    We investigate the spatial extent of rupture and variability in fault slip for micro-earthquakes by inverting seismic moment rate functions derived from empirical Green's function deconvolution. By using waveforms from an array of borehole seismometers, we determine the spatial distributions of fault slip for M 3+ earthquakes that occurred along the Hayward fault in central California and identify a variety of slip behaviors including subevents, directivity, and high stress drop. The 2013 M w 3.2 Orinda earthquake exhibits a complex rupture process involving two subevents with northwest and up-dip directivity. The two subevents release 43 and 18 % of the total seismic moment (6.7 × 1013 N m), and their inferred peak stress drops are 18 and 8 MPa. The 2011 M w 4.0 Berkeley and 2012 M w 4.0 El Cerrito earthquakes are marked by high stress drop. The inferred peak and mean stress drops are about 100-130 and 40 MPa, respectively, which suggests that there are locally high levels of fault strength on the Hayward fault. Our finite-source modeling suggests that the radiation efficiency determined for these two earthquakes is very low (<0.1) and implies that most energy is dissipated during the earthquake rupture process.

  20. Reducing disk storage of full-3D seismic waveform tomography (F3DT) through lossy online compression

    Lindstrom, Peter; Chen, Po; Lee, En-Jui

    2016-08-01

    Full-3D seismic waveform tomography (F3DT) is the latest seismic tomography technique that can assimilate broadband, multi-component seismic waveform observations into high-resolution 3D subsurface seismic structure models. The main drawback in the current F3DT implementation, in particular the scattering-integral implementation (F3DT-SI), is the high disk storage cost and the associated I/O overhead of archiving the 4D space-time wavefields of the receiver- or source-side strain tensors. The strain tensor fields are needed for computing the data sensitivity kernels, which are used for constructing the Jacobian matrix in the Gauss-Newton optimization algorithm. In this study, we have successfully integrated a lossy compression algorithm into our F3DT-SI workflow to significantly reduce the disk space for storing the strain tensor fields. The compressor supports a user-specified tolerance for bounding the error, and can be integrated into our finite-difference wave-propagation simulation code used for computing the strain fields. The decompressor can be integrated into the kernel calculation code that reads the strain fields from the disk and compute the data sensitivity kernels. During the wave-propagation simulations, we compress the strain fields before writing them to the disk. To compute the data sensitivity kernels, we read the compressed strain fields from the disk and decompress them before using them in kernel calculations. Experiments using a realistic dataset in our California statewide F3DT project have shown that we can reduce the strain-field disk storage by at least an order of magnitude with acceptable loss, and also improve the overall I/O performance of the entire F3DT-SI workflow significantly. The integration of the lossy online compressor may potentially open up the possibilities of the wide adoption of F3DT-SI in routine seismic tomography practices in the near future.

  1. High-resolution 3D seismic imaging of a pull-apart basin in the Gulf of Cadiz

    Crutchley, G.; Berndt, C.; Klaeschen, D.; Gutscher, M.

    2009-12-01

    In 2006, high-resolution 3D seismic data were acquired in the Gulf of Cadiz and the Mediterranean Sea aboard the RRS Charles Darwin as part of the HERMES (Hotspot Ecosystem Research on the Margins of European Seas) project. The P-Cable system, a cost-efficient set-up for fast acquisition of 3D seismic data on 12 single-channel streamers, was utilized to acquire seismic cubes at four different targets. Here, we present results from the second target - a WNW-ESE-oriented pull-apart basin in the southeastern Gulf of Cadiz. Initial processing has included: 1) spatial positioning of each recording channel from GPS data acquired on the outer two channels, 2) improved positioning of shot points and channels from the inversion of first arrival times, 3) application of a swell filter to improve reflection coherency, 4) CDP binning and stacking and 5) migration. The new data confirm that the southeastern Gulf of Cadiz north of the Rharb submarine valley is structurally controlled by numerous strike slip faults that were active until quite recently (within the resolution of the data). Given the location of this basin, between the extensional domain on the upper slope and the compressional toe of the accretionary wedge, we interpret the origin to be gravitational sliding on a detachment layer, possibly containing salt, but at this stage not imaged by our profiles.

  2. 3D frequency modeling of elastic seismic wave propagation via a structured massively parallel direct Helmholtz solver

    Wang, S.; De Hoop, M. V.; Xia, J.; Li, X.

    2011-12-01

    We consider the modeling of elastic seismic wave propagation on a rectangular domain via the discretization and solution of the inhomogeneous coupled Helmholtz equation in 3D, by exploiting a parallel multifrontal sparse direct solver equipped with Hierarchically Semi-Separable (HSS) structure to reduce the computational complexity and storage. In particular, we are concerned with solving this equation on a large domain, for a large number of different forcing terms in the context of seismic problems in general, and modeling in particular. We resort to a parsimonious mixed grid finite differences scheme for discretizing the Helmholtz operator and Perfect Matched Layer boundaries, resulting in a non-Hermitian matrix. We make use of a nested dissection based domain decomposition, and introduce an approximate direct solver by developing a parallel HSS matrix compression, factorization, and solution approach. We cast our massive parallelization in the framework of the multifrontal method. The assembly tree is partitioned into local trees and a global tree. The local trees are eliminated independently in each processor, while the global tree is eliminated through massive communication. The solver for the inhomogeneous equation is a parallel hybrid between multifrontal and HSS structure. The computational complexity associated with the factorization is almost linear with the size of the Helmholtz matrix. Our numerical approach can be compared with the spectral element method in 3D seismic applications.

  3. Automated fault extraction and classification using 3-D seismic data for the Ekofisk field development

    Signer, C.; Nickel, M.; Randen, T.; Saeter, T.; Soenneland, H.H.

    1998-12-31

    Mapping of fractures is important for the prediction of fluid flow in many reservoir types. The fluid flow depends mainly on the efficiency of the reservoir seals. Improved spatial mapping of the open and closed fracture systems will allow a better prediction of the fluid flow pattern. The primary objectives of this paper is to present fracture characterization at the reservoir scale combined with seismic facies mapping. The complexity of the giant Ekofisk field on the Norwegian continental shelf provides an ideal framework for testing the validity and the applicability of an automated seismic fault and fracture detection and mapping tool. The mapping of the faults can be based on seismic attribute grids, which means that attribute-responses related to faults are extracted along key horizons which were interpreted in the reservoir interval. 3 refs., 3 figs.

  4. Seismic response of free standing fuel rack construction to 3-D floor motion

    Seismic analysis of free standing submerged racks is complicated by the presence of water and structural non-linearities such as fuel assembly cell impact and floor interface friction. A direct time integration technique has been proposed to analyze this class of structures. Application of the time integration technique on a fourteen degree of freedom lumped mass model of the rack reveals some heretofore unpublished quirks in the structure's behavior. The method of analysis is utilized to compare the seismic response of some representative rack designs. Results show wide differences in the structural response, depending on the fabrication details of racks

  5. Using 3D Simulation of Elastic Wave Propagation in Laplace Domain for Electromagnetic-Seismic Inverse Modeling

    Petrov, P.; Newman, G. A.

    2010-12-01

    -Fourier domain we had developed 3D code for full-wave field simulation in the elastic media which take into account nonlinearity introduced by free-surface effects. Our approach is based on the velocity-stress formulation. In the contrast to conventional formulation we defined the material properties such as density and Lame constants not at nodal points but within cells. This second order finite differences method formulated in the cell-based grid, generate numerical solutions compatible with analytical ones within the range errors determinate by dispersion analysis. Our simulator will be embedded in an inversion scheme for joint seismic- electromagnetic imaging. It also offers possibilities for preconditioning the seismic wave propagation problems in the frequency domain. References. Shin, C. & Cha, Y. (2009), Waveform inversion in the Laplace-Fourier domain, Geophys. J. Int. 177(3), 1067- 1079. Shin, C. & Cha, Y. H. (2008), Waveform inversion in the Laplace domain, Geophys. J. Int. 173(3), 922-931. Commer, M. & Newman, G. (2008), New advances in three-dimensional controlled-source electromagnetic inversion, Geophys. J. Int. 172(2), 513-535. Newman, G. A., Commer, M. & Carazzone, J. J. (2010), Imaging CSEM data in the presence of electrical anisotropy, Geophysics, in press.

  6. Assessing earthquake source models using 3-D forward modelling of long-period seismic data: application to the SCARDEC method

    Ferreira, Ana Mg; Vallee, Martin; Charlety, Jean

    2010-05-01

    Accurate earthquake point source parameters (e.g. seismic moment, depth and focal mechanism) provide key first-order information for detailed studies of the earthquake source process and for improved seismic and tsunami hazard evaluation. In order to objectively assess the quality of seismic source models, it is important to go beyond classical resolution checks. In particular, it is desirable to apply sophisticated modelling techniques to quantify inaccuracies due to simplified theoretical formulations and/or Earth structure employed to build the source models. Moreover, it is important to verify how well the models explain data not used in their construction. In this study we assess the quality of the SCARDEC method (see joint abstracts), which is a new automated technique that retrieves simultaneously the seismic moment, focal mechanism, depth and source time functions of large earthquakes. Because the SCARDEC method is based on body-wave deconvolution using ray methods in a 1D Earth model, we test how well SCARDEC source parameters explain long-period seismic data (surface waves and normal modes). We calculate theoretical seismograms using two forward modelling techniques (full ray theory and spectral element method) to simulate the long-period seismic wavefield for the 3D Earth model S20RTS combined with the crust model CRUST2.0, and for two point source models: (i) the SCARDEC model; and (ii) the Global CMT model. We compare the synthetic seismograms with real broadband data from the FDSN for the major subduction earthquakes of the last 20 years. We show that SCARDEC source parameters explain long-period surface waves as well as Global CMT solutions. This can be explained by the fact that most of the differences between SCARDEC and Global CMT solutions are linked to correlated variations of the seismic moment and dip of the earthquakes, and it is theoretically known that for shallow earthquakes it is difficult to accurately resolve these two parameters using

  7. Modeling seismic wave propagation and amplification in 1D/2D/3D linear and nonlinear unbounded media

    Semblat, Jean-François

    2011-01-01

    To analyze seismic wave propagation in geological structures, it is possible to consider various numerical approaches: the finite difference method, the spectral element method, the boundary element method, the finite element method, the finite volume method, etc. All these methods have various advantages and drawbacks. The amplification of seismic waves in surface soil layers is mainly due to the velocity contrast between these layers and, possibly, to topographic effects around crests and hills. The influence of the geometry of alluvial basins on the amplification process is also know to be large. Nevertheless, strong heterogeneities and complex geometries are not easy to take into account with all numerical methods. 2D/3D models are needed in many situations and the efficiency/accuracy of the numerical methods in such cases is in question. Furthermore, the radiation conditions at infinity are not easy to handle with finite differences or finite/spectral elements whereas it is explicitely accounted in the B...

  8. Construction method and application of 3D velocity model for evaluation of strong seismic motion and its cost performance

    Based on experiences of making subsurface structure models for seismic strong motion evaluation, the advantages and disadvantages in terms of convenience and cost for several methods used to make such models were reported. As for the details, gravity and micro-tremor surveys were considered to be highly valid in terms of convenience and cost. However, stratigraphy and seismic velocity structure are required to make accurate 3-D subsurface structures. To realize these, methods for directly examining subsurface ground or using controlled tremor sources (at high cost) are needed. As a result, it was summarized that in modeling subsurface structures, some sort of plan including both types of methods is desirable and that several methods must be combined to match one's intended purposes and budget. (authors)

  9. 3D seismic modeling and reverse‐time migration with the parallel Fourier method using non‐blocking collective communications

    Chu, Chunlei

    2009-01-01

    The major performance bottleneck of the parallel Fourier method on distributed memory systems is the network communication cost. In this study, we investigate the potential of using non‐blocking all‐to‐all communications to solve this problem by overlapping computation and communication. We present the runtime comparison of a 3D seismic modeling problem with the Fourier method using non‐blocking and blocking calls, respectively, on a Linux cluster. The data demonstrate that a performance improvement of up to 40% can be achieved by simply changing blocking all‐to‐all communication calls to non‐blocking ones to introduce the overlapping capability. A 3D reverse‐time migration result is also presented as an extension to the modeling work based on non‐blocking collective communications.

  10. Analysis of allochthonous salt and salt welds in the northern Gulf of Mexico utilizing 3D seismic data

    Pritchett, J.A.; House, W.M. [Amoco Production Co., Houston, TX (United States)

    1996-12-31

    The widespread availability of 3D seismic data sets in the northern Gulf of Mexico has resulted in the emergence of new play concepts such as subsalt exploration. Time and depth migrations of these 3D data allow interpreters to develop a detailed understanding of the geological processes that contribute to the structural and stratigraphic framework of the Gulf. These data provide excellent imaging of structural features, and result in the correct spatial positioning of those structural elements. Analysis of the geometrical relationships between allochthonous salt, salt welds and subsalt reflectors aids in the development of salt emplacement models. These models are subsequently tied to other elements of the hydrocarbon system such as fluid migration and reservoir development. Salt sheets and horizontal salt welds often separate distinct structural domains in the supra salt and subsalt section, and complex structural deformation above salt or a salt weld may not translate into the subsalt section.

  11. Analysis of allochthonous salt and salt welds in the northern Gulf of Mexico utilizing 3D seismic data

    Pritchett, J.A.; House, W.M. (Amoco Production Co., Houston, TX (United States))

    1996-01-01

    The widespread availability of 3D seismic data sets in the northern Gulf of Mexico has resulted in the emergence of new play concepts such as subsalt exploration. Time and depth migrations of these 3D data allow interpreters to develop a detailed understanding of the geological processes that contribute to the structural and stratigraphic framework of the Gulf. These data provide excellent imaging of structural features, and result in the correct spatial positioning of those structural elements. Analysis of the geometrical relationships between allochthonous salt, salt welds and subsalt reflectors aids in the development of salt emplacement models. These models are subsequently tied to other elements of the hydrocarbon system such as fluid migration and reservoir development. Salt sheets and horizontal salt welds often separate distinct structural domains in the supra salt and subsalt section, and complex structural deformation above salt or a salt weld may not translate into the subsalt section.

  12. Combined Borehole Seismic and Electromagnetic Inversion For High-Resolution Petrophysical Assessment Of Hydocarbon Reservoirs

    Carlos Torres-Verdin; G. Michael Hoversten; Ki Ha Lee; Gregory Newman; Kurt Nihei

    2008-12-31

    This report summarizes the work performed between January 2005 and December 2007, under DOE research contract DE-FC26-04NT15507. The project is was performed by the Center for Petroleum and Geosystems Engineering of The University of Texas at Austin and Lawrence Berkeley National Laboratory under the auspices of the National Energy Technology Office (NETL) and the Strategic Center for Natural Gas and Oil (SCNGO). During the three-year project, we developed new methods to combine borehole sonic and electromagnetic (EM) measurements for the improved assessment of elastic and petrophysical properties of rock formations penetrated by a well. Sonic measurements consisted of full waveform acoustic amplitudes acquired with monopole and dipole sources, whereas EM measurements consisted of frequency-domain voltages acquired with multi-coil induction systems. The combination of sonic and EM measurements permitted the joint estimation of elastic and petrophysical properties in the presence of mud-filtrate invasion. It was conclusively shown that the combined interpretation of sonic and EM measurements reduced non-uniqueness in the estimation of elastic and petrophysical properties and improved the spatial resolution of the estimations compared to estimations yielded separately from the two types of measurements. Moreover, this approach enabled the assessment of dynamic petrophysical properties such as permeability, as it incorporated the physics of mud-filtrate invasion in the interpretation of the measurements. The first part of the project considered the development of fast and reliable numerical algorithms to simulate borehole sonic waveforms in 2D, 3D, and radial 1D media. Such algorithms were subsequently used in the quantitative estimation of elastic properties jointly from borehole sonic and EM measurements. In the second part of the project we developed a new algorithm to estimate water saturation, porosity, and dry-rock elastic moduli jointly from borehole sonic and

  13. Results From a Borehole Seismometer Array II: 3-D Mapping of an Active Geothermal Field at the Kilauea Lower Rift Zone

    Shalev, E.; Kenedi, C. L.; Malin, P.

    2008-12-01

    The geothermal power plant in Puna, in southeastern Hawaii, is located in a section of the Kilauea Lower East Rift Zone that was resurfaced by lava flows as recently as 1955, 1960, and 1972. In 2006 a seismic array consisting of eight 3-component stations was installed around the geothermal field in Puna. The instrument depths range from 24 to 210 m. The shallower instruments have 2 Hz geophones and the deeper have 4.5 Hz geophones. 3-D tomographic analyses of P-wave velocity, S-wave velocity, and the Vp/Vs ratio show an area of very fast P-wave velocity at the relatively shallow depth of 2.5 km in the southern section of the field. The same area shows moderate S-wave velocity. This high P-wave velocity anomaly at the southern part of the geothermal field may indicate the presence of dense rock material usually found at greater depths.

  14. 3D seismic experiment in difficult area in Japan; Kokunai nanchiiki ni okeru sanjigen jishin tansa jikken

    Minegishi, M.; Nakagami, K.; Tanaka, H. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1997-05-27

    Difficult area in this context means an exploration-difficult area supposed to store oil/gas but retarded in exploration for the lack of knowledge about the geological structure due to poor quality of available seismic survey records. Discussed in this paper is a survey conducted into an area covering the southern part of Noshiro-shi, Akita-ken, and Yamamoto-cho, Yamamoto-gun, Akita-ken. An area size suitable for data collection at a target depth of 2500m is determined using an interpretation structure compiled on the basis of available well data and 2D seismic survey data. The plan for siting shock points and receiving points is modified case by case as restrictive factors come to the surface (resulting from the complicated hilly terrain, presence of pipes for agricultural water, etc.). The peculiarities of seismic waves in the terrain are studied through the interpretation of the available well data and 2D seismic survey data for the construction of a 3D velocity model for the confirmation of the appropriateness of the plan for siting shock points and receiving points. Efforts are exerted through enhanced coordination with the contractor to acquire data so that a technologically best design may be won within the limits of the budget. The quality of the data obtained from this experiment is in general better than those obtained from previous experiments, yet many problems remain to be settled in future studies about exploration-difficult areas. 4 refs., 4 figs., 1 tab.

  15. Incorporating higher order WINKLER springs with 3-D finite element model of a reactor building for seismic SSI analysis

    In order to fulfill the seismic safety requirements, in the frame of seismic requalification activities for NPP Muehleberg, Switzerland, detailed seismic analysis performed on the Reactor Building and the results are presented previously. The primary objective of the present investigation is to assess the seismic safety of the reinforced concrete structures of reactor building. To achieve this objective requires a rather detailed 3-D finite element modeling for the outer shell structures, the drywell, the reactor pools, the floor decks and finally, the basemat. This already is a complicated task, which enforces need for simplifications in modelling the reactor internals and the foundation soil. Accordingly, all internal parts are modelled by vertical sticks and the Soil Structure Interaction (SSI) effects are represented by sets of transitional and higher order rotational WINKLER springs, i.e. avoiding complicated finite element SSI analysis. As a matter of fact, the availability of the results of recent investigations carried out on the reactor building using diversive finite element SSI analysis methods allow to calibrate the WINKLER springs, ensuring that the overall SSI behaviour of the reactor building is maintained

  16. Mantle fabric of western Bohemian Massif (central Europe) constrained by 3D seismic P and S anisotropy

    Babuška, Vladislav; Plomerová, Jaroslava; Vecsey, Luděk

    2008-01-01

    Roč. 462, č. 1-4 (2008), s. 149-163. ISSN 0040-1951 R&D Projects: GA ČR GA205/04/0748; GA ČR GA205/07/1088; GA AV ČR(CZ) KJB300120605 Institutional research plan: CEZ:AV0Z30120515 Keywords : Bohemian Massif * P and S seismic anisotropy * 3D fabric of mantle lithosphere Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.677, year: 2008

  17. 3D Seismic Characterization of the Research Facility for Geological Storage of CO2: Hontomín (Burgos, Spain)

    Alcalde, J.; Martí, D.; Calahorrano, A.; Marzan, I.; Ayarza, P.; Carbonell, R.; Perez-Estaun, A.

    2011-12-01

    A technological research facility dedicated to the underground geological storage of CO2 is currently being developed by the Spanish research program on Carbon Capture and Storage (CCS) in Hontomin (Burgos, North of the Iberian Peninsula) This research program is being developed by the CIUDEN Foundation. CIUDEN is an initiative of 3 Spanish state departments (Science & Innovation, Environment and Industry). An extensive multidisciplinary site characterization phase has been carried out, including a multi-seismic data acquisition experiment. Within this effort a 36 km2 academic-oriented 3D seismic reflection survey was acquired in summer 2010. The aim of data acquisition effort are to provide high resolution images of the subsurface of the storage complex, constrain a baseline model for all the disciplines involved in the project. The main acquisition characteristics of this survey included: a mixed source (Vibroseis & explosive , 74% and 26% of the source points, respectively); 5000 shot points, distributed along 22 source lines (separated 250 m), 22 lines of receivers (separated 275 m); shot and receiver spacing along the source and receiver lines was of 25 m; this resulted in a nominal CDP-fold of 36 traces, with 13 m2 bins. This 3D-data was fully processed until migration. The main features within the processing sequence include static correction calculation, frequency filtering, trace amplitude equalization, rms velocity modeling, FK-domain filtering, 3D deconvolution, dip move-out corrections, residual static calculation and pre and post stack migration. The final high-resolution 3D-volume allowed to characterize the main tectonic structure of the dome complex, the fault system of the area and the feasibility of the reservoir for the storage. The target reservoir is a saline aquifer placed at 1400, approximately, within Lower Jurassic carbonates (Lias); the main seal is formed by inter-layered marls and marly limestones from Early to Middle Jurassic (Dogger

  18. Integrating Ground Penetrating Radar, Electrical Resistivity, Seismic Refraction, and Borehole Data to Image an Alluvial Aquifer in Three Dimensions

    Bailey, B. L.; Marshall, S. T.; Anderson, W. P.

    2010-12-01

    In this study we image the subsurface of a mountain stream floodplain in order to determine the three-dimensional aquifer geometry and degree of hydrologic connectivity. On site borehole data provides detailed information about the subsurface including direct measurements of depth to the water table; however, boreholes are not cost effective over a large area, the existing boreholes only have a penetration depth of ~3 meters, and subsurface stratigraphic features may only be locally present. We therefore combine borehole data with ground-penetrating radar (GPR), electrical resistivity, and seismic refraction data collected in linear transects perpendicular to the stream in order to effectively image a larger portion of the subsurface in three-dimensions. GPR data images several buried/abandoned channels, but no significant hydrologic barriers, such as clay lenses, have been found. Strong shallow reflectors in GPR data correlate to borehole measurements of water table depth and indicate a relatively flat water table surface. Furthermore, the GPR data show strong reflectors at the bedrock/sedimentary basin interface, which appears to dip towards the river mimicking the nearby surface topography. Resistivity transects also clearly delineate the water table and bedrock interface, reinforcing the GPR results. Seismic refraction data successfully resolves the dipping nature of the bedrock interface beyond the GPR penetration depth. Because bedrock was only encountered in one borehole, integrating the geophysical data provides constraints on overall aquifer volume. Future modeling studies of groundwater dynamics will better represent realistic aquifer properties by utilizing the data gathered here. Our continuing work will involve comparing the effectiveness of each geophysical technique for specific geologic targets, determining which techniques have the best resolution, and expanding the survey region.

  19. 9C-3D seismic interpretation of the Bakken Formation, Banner Field, North Dakota

    Comegys, Lillian R.

    The Bakken Petroleum System is a multi-reservoir play with estimated total undiscovered resources of 3.649 BBO oil and 1.85 TCF natural gas in the United States portion of the Williston Basin (Pollastro 2008). The presence of natural fractures in all three members of the Bakken Formation have been linked to high initial production (IP) and cumulative production from the Antelope Field and better reservoir potential in the Elm Coulee Field and Sanish Fields (Sturm and Gomez 2009; Honsberger 2012; Theloy 2011). Therefore, the ability of seismic data to determine the presence, orientation, and density of natural fractures is an important achievement for petroleum exploration and exploitation. The STAMPEDE 9-component seismic survey is located in Mountrail County, North Dakota, in the Banner Field, southeast of the Parshall and Sanish Fields. It is the goal of the Reservoir Characterization Project to analyze the structural influences on reservoir properties in the STAMPEDE survey area using the compressional and pure shear seismic volumes supplemented by the public well information available on the North Dakota Industrial Commission website. Fracturing induced by basement faulting and lithology changes is detectable using multicomponent seismic data in the Stampede seismic survey. Shear wave splitting analysis delineates zones of different fracture orientation and density. These areas correlate to interpreted fault intersections and the predicted area of increased fracture frequency based on facies changes in the Middle Bakken Member and its mechanical stratigraphy. Wrench fault mechanics are at work in the study area, creating isolated convergent and divergent stress regimes in the separate fault blocks. Main fault interpretations are based on shear wave isochron mapping, wireline log mapping, seismic panel observations. Fracture interpretations were made on the analysis of shear time and amplitude anisotropy maps and the correlation of a P-wave Velocity Variation

  20. High resolution processing of 3D seismic data for thin coal seam in Guqiao coal mine

    Li, Qiaoling; Peng, Suping; Zou, Guangui

    2015-04-01

    Accurate identification of small faults for coal seams is very important for coal-field exploration, which can greatly improve mining efficiency and safety. However, coal seams in China are mostly thin layers, ranging from 2-5 m. Moreover, the shallow coal seam with strong reflection forms a shield underneath thin coal seam which is only about 40 m deeper. This causes great difficulty in seismic processing and interpretation. The primary concern is to obtain high-resolution seismic image of underneath thin coal seam for mining safety. In this paper, field data is carefully analyzed and fit-for-purpose solutions are adopted in order to improve the quality of reprocessed data and resolution of target coal seam. Identification of small faults has been enhanced significantly.

  1. 3D FEM Numerical Simulation of Seismic Pile-supported Bridge Structure Reaction in Liquefying Ground

    Ling XianZhang, Tang Liang and Xu Pengju

    2011-04-01

    Full Text Available This study examines the establishment of liquefied ground pile-soil-bridge seismic interaction analysis of three-dimensional finite element analysis method for the simulation of liquefied ground shaking table test of pile-soil seismic interaction analysis, undertake OpenSees finite element based numerical simulation platform, for the shaking table test based on two-phase saturated porous media, Comparative numerical and experimental results, detailed test pile dynamic response of bridge structure and dynamic properties, especially liquefaction pore pressure, liquefaction of pile foundation and the dynamic response of the free field. Finite element method can reasonably predict the site of pore pressure, dynamic response; despite the conventional beam element simulation of pile, pile dynamic response can still accurately simulated.

  2. 3-D surface wave tomography of the Piton de la Fournaise volcano using seismic noise correlations

    Brenguier, Florent; M. Shapiro, Nikolai; Campillo, Michel; Nercessian, Alexandre; Ferrazzini, Valérie

    2007-01-01

    [1] We invert Rayleigh waves reconstructed from cross-correlations of 18 months of ambient seismic noise recorded by permanent seismological stations run by the Piton de la Fournaise Volcanological Observatory. By correlating noise records between 21 receivers, we reconstruct Rayleigh waves with sufficient signal-to-noise ratio for 210 inter-station paths. We use the reconstructed waveforms to measure group velocity dispersion curves at periods between 1.5 and 4.5 s. The obtained measurements...

  3. A comparison of methods for 3D target localization from seismic and acoustic signatures

    ELBRING,GREGORY J.; GARBIN,H. DOUGLAS; LADD,MARK D.

    2000-04-03

    An important application of seismic and acoustic unattended ground sensors (UGS) is the estimation of the three dimensional position of an emitting target. Seismic and acoustic data derived from UGS systems provide the taw information to determine these locations, but can be processed and analyzed in a number of ways using varying amounts of auxiliary information. Processing methods to improve arrival time picking for continuous wave sources and methods for determining and defining the seismic velocity model are the primary variables affecting the localization accuracy. Results using field data collected from an underground facility have shown that using an iterative time picking technique significantly improves the accuracy of the resulting derived target location. Other processing techniques show little advantage over simple crosscorrelation along in terms of accuracy, but may improve the ease with which time picks can be made. An average velocity model found through passive listening or a velocity model determined from a calibration source near the target source both result in similar location accuracies, although the use of station correction severely increases the location error.

  4. Extending field life in offshore Gulf of Mexico using 3-D seismic survey

    Bulling, T.P.; Olsen, R.S. (ARCO Oil and Gas Co., Houston, TX (USA))

    1990-05-01

    Discovered by ARCO in 1967, the High Island 24L field (lower Miocene) is located in the Texas state waters of the Gulf of Mexico. By 1986, the field had produced 320 billion ft{sup 3} of gas and 3.0 million bbl of oil. An engineering field study completed in 1986 showed the field was declining and would be unprofitable within 3 yr. Study of reservoir maps revealed three basin problems: volumetric reserve calculations were less than reserves produced, hydrocarbon-water contacts were inconsistent between wells thought to be in communication, and ultimate recoveries could not be accurately calculated. Attempts to remap the field with the existing two-dimensional seismic data base and well data proved unsuccessful. In 1986, a three-dimensional seismic survey was acquired in an effort to evaluate the true present worth and potential of the field. Remapping of 30 reservoir horizons began in 1987. The integration of detailed well log correlations tied to the dense grid of quality three dimensional seismic data improved the reservoir maps. These maps helped resolve engineering problems by defining the configuration of the reservoirs more accurately. Reservoir maps now closely match volumetrics, fluid contacts within reservoir units are consistent, and a better definition of extension well opportunities exists. The authors study resulted in six additional wells. These wells along with engineering modifications and operations cost containment resulted in the extension of the economic life of the High Island 24-L field by at least 8 yr.

  5. Anomalous fluid emission of a deep borehole in a seismically active area of Northern Apennines (Italy)

    The Miano borehole, 1047 m deep, is located close to the river Parma in the Northern Apennines, Italy. A measuring station has been installed to observe the discharge of fluids continuously since November 2004. The upwelling fluid of this artesian well is a mixture of thermal water and CH4 as main components. In non-seismogenic areas, a relatively constant fluid emission would be expected, perhaps overlaid with long term variations from that kind of deep reservoir over time. However, the continuous record of the fluid emission, in particular the water discharge, the gas flow rate and the water temperature, show periods of stable values interrupted by anomalous periods of fluctuations in the recorded parameters. The anomalous variations of these parameters are of low amplitude in comparison to the total values but significant in their long-term trend. Meteorological effects due to rain and barometric pressure were not detected in recorded data probably due to reservoir depth and relatively high reservoir overpressure. Influences due to the ambient temperature after the discharge were evaluated by statistical analysis. Our results suggest that recorded changes in fluid emission parameters can be interpreted as a mixing process of different fluid components at depth by variations in pore pressure as a result of seismogenic stress variation. Local seismicity was analyzed in comparison to the fluid physico-chemical data. The analysis supports the idea that an influence on fluid transport conditions due to geodynamic processes exists. Water temperature data show frequent anomalies probably connected with possible precursory phenomena of local seismic events.

  6. Development and Test of a 1,000 Level 3C Fiber Optic Borehole Seismic Receiver Array Applied to Carbon Sequestration

    Paulsson, Bjorn N.P. [Paulsson, Inc., Van Nuys, CA (United States)

    2015-02-28

    To address the critical site characterization and monitoring needs for CCS programs, US Department of Energy (DOE) awarded Paulsson, Inc. in 2010 a contract to design, build and test a fiber optic based ultra-large bandwidth clamped borehole seismic vector array capable of deploying up to one thousand 3C sensor pods suitable for deployment into high temperature and high pressure boreholes. Paulsson, Inc. has completed a design or a unique borehole seismic system consisting of a novel drill pipe based deployment system that includes a hydraulic clamping mechanism for the sensor pods, a new sensor pod design and most important – a unique fiber optic seismic vector sensor with technical specifications and capabilities that far exceed the state of the art seismic sensor technologies. These novel technologies were all applied to the new borehole seismic system. In combination these technologies will allow for the deployment of up to 1,000 3C sensor pods in vertical, deviated or horizontal wells. Laboratory tests of the fiber optic seismic vector sensors developed during this project have shown that the new borehole seismic sensor technology is capable of generating outstanding high vector fidelity data with extremely large bandwidth: 0.01 – 6,000 Hz. Field tests have shown that the system can record events at magnitudes much smaller than M-2.3 at frequencies up to 2,000 Hz. The sensors have also proved to be about 100 times more sensitive than the regular coil geophones that are used in borehole seismic systems today. The fiber optic seismic sensors have furthermore been qualified to operate at temperatures over 300°C (572°F). The fibers used for the seismic sensors in the system are used to record Distributed Temperature Sensor (DTS) data allowing additional value added data to be recorded simultaneously with the seismic vector sensor data.

  7. Investigation on the real-time prediction of ground motions using seismic records observed in deep boreholes

    Miyakoshi, H.; Tsuno, S.

    2013-12-01

    The present method of the EEW system installed in the railway field of Japan predicts seismic ground motions based on the estimated earthquake information about epicentral distances and magnitudes using initial P-waves observed on the surface. In the case of local earthquakes beneath the Tokyo Metropolitan Area, however, a method to directly predict seismic ground motions using P-waves observed in deep boreholes could issue EEWs more simply and surely. Besides, a method to predict seismic ground motions, using S-waves observed in deep boreholes and S-wave velocity structures beneath seismic stations, could show planar distributions of ground motions for train operation control areas in the aftermath of earthquakes. This information is available to decide areas in which the emergency inspection of railway structures should be performed. To develop those two methods, we investigated relationships between peak amplitudes on the surface and those in deep boreholes, using seismic records of KiK-net stations in the Kanto Basin. In this study, we used earthquake accelerograms observed in boreholes whose depths are deeper than the top face of Pre-Neogene basement and those on the surface at 12 seismic stations of KiK-net. We selected 243 local earthquakes whose epicenters are located around the Kanto Region. Those JMA magnitudes are in the range from 4.5 to 7.0. We picked the on-set of P-waves and S-waves using a vertical component and two horizontal components, respectively. Peak amplitudes of P-waves and S-waves were obtained using vertical components and vector sums of two horizontal components, respectively. We estimated parameters which represent site amplification factors beneath seismic stations, using peak amplitudes of S-waves observed in the deep borehole and those on the surface, to minimize the residuals between calculations by the theoretical equation and observations. Correlation coefficients between calculations and observations are high values in the range

  8. Seismic time-lapse monitoring of potential gas hydrate dissociation around boreholes : could it be feasible? A conceptual 2D study linking geomechanical and seismic FD models

    Pecher, I.; Yang, J.; Anderson, R.; Tohidi, B.; MacBeth, C. [Heriot-Watt Univ., Edinburgh (United Kingdom). Inst. of Petroleum Engineering; Freij-Ayoub, R.; Clennell, B. [CSIRO Petroleum, Bentley, WA (Australia)

    2008-07-01

    Dissociation of gas hydrate to water and potentially overpressured gas around boreholes may pose a hazard for deep-water hydrocarbon production. Strategies to mitigate this risk include monitoring for early detection of dissociation. Seismic methods are especially promising, primarily because of a high sensitivity of P-wave velocity to gas in the pore space of unconsolidated sediments. This paper presented a study that applied commonly used rock physics modeling to predict the seismic response to gas hydrate dissociation with a focus on P-impedance and performed sensitivity tests. The geomechanical model was translated into seismic models. In order to determine which parameters needed to be particularly well calibrated in experimental and modeling studies, the sensitivity of seismic properties to a variation of input parameters was estimated. The seismic response was predicted from dissociating gas hydrates using two-dimensional finite-difference wave-propagation modeling to demonstrate that despite the small predicted lateral extent of hydrate dissociation, its pronounced effect on seismic properties should allow detection with a seismic source on a drilling platform and receivers on the seafloor. The paper described the methods, models, and results of the study. It was concluded that the key factors for predicting the seismic response of sediments to hydrate dissociation were the mode of gas hydrate distribution, gas distribution in the sediments, gas saturation, and pore pressure. 33 refs., 3 tabs., 8 figs.

  9. 3D Finite-Difference Modeling of Acoustic Radiation from Seismic Sources

    Chael, E. P.; Aldridge, D. F.; Jensen, R. P.

    2013-12-01

    Shallow seismic events, earthquakes as well as explosions, often generate acoustic waves in the atmosphere observable at local or even regional distances. Recording both the seismic and acoustic signals can provide additional constraints on source parameters such as epicenter coordinates, depth, origin time, moment, and mechanism. Recent advances in finite-difference (FD) modeling methods enable accurate numerical treatment of wave propagation across the ground surface between the (solid) elastic and (fluid) acoustic domains. Using a fourth-order, staggered-grid, velocity-stress FD algorithm, we are investigating the effects of various source parameters on the acoustic (or infrasound) signals transmitted from the solid earth into the atmosphere. Compressional (P), shear (S), and Rayleigh waves all radiate some acoustic energy into the air at the ground surface. These acoustic wavefronts are typically conical in shape, since their phase velocities along the surface exceed the sound speed in air. Another acoustic arrival with a spherical wavefront can be generated from the vicinity of the epicenter of a shallow event, due to the strong vertical ground motions directly above the buried source. Images of acoustic wavefields just above the surface reveal the radiation patterns and relative amplitudes of the various arrivals. In addition, we compare the relative effectiveness of different seismic source mechanisms for generating acoustic energy. For point sources at a fixed depth, double-couples with almost any orientation produce stronger acoustic signals than isotropic explosions, due to higher-amplitude S and Rayleigh waves. Of course, explosions tend to be shallower than most earthquakes, which can offset the differences due to mechanism. Low-velocity material in the shallow subsurface acts to increase vertical seismic motions there, enhancing the coupling to acoustic waves in air. If either type of source breaks the surface (e.g., an earthquake with surface rupture

  10. Modeling 3-D flow in the mantle wedge with complex slab geometries: Comparisons with seismic anisotropy

    Kincaid, C. R.; MacDougall, J. G.; Druken, K. A.; Fischer, K. M.

    2010-12-01

    Understanding patterns in plate scale mantle flow in subduction zones is key to models of thermal structure, dehydration reactions, volatile distributions and magma generation and transport in convergent margins. Different patterns of flow in the mantle wedge can generate distinct signatures in seismological observables. Observed shear wave fast polarization directions in several subduction zones are inconsistent with predictions of simple 2-D wedge corner flow. Geochemical signatures in a number of subduction zones also indicate 3-D flow and entrainment patterns in the wedge. We report on a series of laboratory experiments on subduction driven flow to characterize spatial and temporal variability in 3-D patterns in flow and shear-induced finite strain. Cases focus on how rollback subduction, along-strike dip changes in subducting plates and evolving gaps or tears in subduction zones control temporal-spatial patterns in 3-D wedge flow. Models utilize a glucose working fluid with a temperature dependent viscosity to represent the upper 2000 km of the mantle. Subducting lithosphere is modeled with two rubber-reinforced continuous belts. Belts pass around trench and upper/lower mantle rollers. The deeper rollers can move laterally to allow for time varying dip angle. Each belt has independent speed control and dip adjustment, allowing for along-strike changes in convergence rate and the evolution of slab gaps. Rollback is modeled using a translation system to produce either uniform and asymmetric lateral trench motion. Neutral density finite strain markers are distributed throughout the fluid and used as proxies for tracking the evolution of anisotropy through space and time in the evolving flow fields. Particle image velocimetry methods are also used to track time varying 3-D velocity fields for directly calculating anisotropy patterns. Results show that complex plate motions (rollback, steepening) and morphologies (gaps) in convergent margins produce flows with

  11. Seismically Initiated Carbon Dioxide Gas Bubble Growth in Groundwater: A Mechanism for Co-seismic Borehole Water Level Rise and Remotely Triggered Secondary Seismicity

    Crews, Jackson B.

    of freshwater. Co-seismic borehole water level increases of the same magnitude were observed in Parkfield, California, and Long Valley caldera, California, in response to the propagation of a Rayleigh wave in the same amplitude and frequency range produced by the June 28, 1992 MW 7.3 Landers, California, earthquake. Co-seismic borehole water level rise is well documented in the literature, but the mechanism is not well understood, and the results of core-scale experiments indicate that seismically initiated CO2 gas bubble nucleation and growth in groundwater is a reasonable mechanism. Remotely triggered secondary seismicity is also well documented, and the reduction of effective stress due to CO2 bubble nucleation and growth in critically loaded faults may potentially explain how, for example, the June 28, 1992 MW 7.3 Landers, California, earthquake triggered seismicity as far away as Yellowstone, Wyoming, 1250 km from the hypocenter. A numerical simulation was conducted using Euler's method and a first-order kinetic model to compute the pore fluid pressure response to confining stress excursions on a Berea sandstone core flooded with initially under-saturated aqueous CO2. The model was calibrated on the pore pressure response to a rapid drop and later recovery of the confining stress. The model predicted decreasing overpressure as the confining stress oscillation frequency increased from 0.05 Hz to 0.30 Hz, in contradiction with the experimental results and field observations, which exhibit larger excess pore fluid pressure in response to higher frequency oscillations. The limitations of the numerical model point to the important influence of non-ideal behavior arising from a discontinuous gas phase and complex dynamics at the gas-liquid interface.

  12. INCREASING OIL RECOVERY THROUGH ADVANCED REPROCESSING OF 3D SEISMIC, GRANT CANYON AND BACON FLAT FIELDS, NYE COUNTY, NEVADA

    Eric H. Johnson; Don E. French

    2001-06-01

    Makoil, Inc., of Orange, California, with the support of the U.S. Department of Energy has reprocessed and reinterpreted the 3D seismic survey of the Grant Canyon area, Railroad Valley, Nye County, Nevada. The project was supported by Dept. of Energy Grant DE-FG26-00BC15257. The Grant Canyon survey covers an area of 11 square miles, and includes Grant Canyon and Bacon Flat oil fields. These fields have produced over 20 million barrels of oil since 1981, from debris slides of Devonian rocks that are beneath 3,500 to 5,000 ft of Tertiary syntectonic deposits that fill the basin of Railroad Valley. High-angle and low-angle normal faults complicate the trap geometry of the fields, and there is great variability in the acoustic characteristics of the overlying valley fill. These factors combine to create an area that is challenging to interpret from seismic reflection data. A 3D seismic survey acquired in 1992-93 by the operator of the fields has been used to identify development and wildcat locations with mixed success. Makoil believed that improved techniques of processing seismic data and additional well control could enhance the interpretation enough to improve the chances of success in the survey area. The project involved the acquisition of hardware and software for survey interpretation, survey reprocessing, and reinterpretation of the survey. SeisX, published by Paradigm Geophysical Ltd., was chosen as the interpretation software, and it was installed on a Dell Precision 610 computer work station with the Windows NT operating system. The hardware and software were selected based on cost, possible addition of compatible modeling software in the future, and the experience of consulting geophysicists in the Billings area. Installation of the software and integration of the hardware into the local office network was difficult at times but was accomplished with some technical support from Paradigm and Hewlett Packard, manufacturer of some of the network equipment. A

  13. INCREASING OIL RECOVERY THROUGH ADVANCED REPROCESSING OF 3D SEISMIC, GRANT CANYON AND BACON FLAT FIELDS, NYE COUNTY, NEVADA

    Makoil, Inc., of Orange, California, with the support of the U.S. Department of Energy has reprocessed and reinterpreted the 3D seismic survey of the Grant Canyon area, Railroad Valley, Nye County, Nevada. The project was supported by Dept. of Energy Grant DE-FG26-00BC15257. The Grant Canyon survey covers an area of 11 square miles, and includes Grant Canyon and Bacon Flat oil fields. These fields have produced over 20 million barrels of oil since 1981, from debris slides of Devonian rocks that are beneath 3,500 to 5,000 ft of Tertiary syntectonic deposits that fill the basin of Railroad Valley. High-angle and low-angle normal faults complicate the trap geometry of the fields, and there is great variability in the acoustic characteristics of the overlying valley fill. These factors combine to create an area that is challenging to interpret from seismic reflection data. A 3D seismic survey acquired in 1992-93 by the operator of the fields has been used to identify development and wildcat locations with mixed success. Makoil believed that improved techniques of processing seismic data and additional well control could enhance the interpretation enough to improve the chances of success in the survey area. The project involved the acquisition of hardware and software for survey interpretation, survey reprocessing, and reinterpretation of the survey. SeisX, published by Paradigm Geophysical Ltd., was chosen as the interpretation software, and it was installed on a Dell Precision 610 computer work station with the Windows NT operating system. The hardware and software were selected based on cost, possible addition of compatible modeling software in the future, and the experience of consulting geophysicists in the Billings area. Installation of the software and integration of the hardware into the local office network was difficult at times but was accomplished with some technical support from Paradigm and Hewlett Packard, manufacturer of some of the network equipment. A

  14. Development of a State-Wide 3-D Seismic Tomography Velocity Model for California

    Thurber, C. H.; Lin, G.; Zhang, H.; Hauksson, E.; Shearer, P.; Waldhauser, F.; Hardebeck, J.; Brocher, T.

    2007-12-01

    We report on progress towards the development of a state-wide tomographic model of the P-wave velocity for the crust and uppermost mantle of California. The dataset combines first arrival times from earthquakes and quarry blasts recorded on regional network stations and travel times of first arrivals from explosions and airguns recorded on profile receivers and network stations. The principal active-source datasets are Geysers-San Pablo Bay, Imperial Valley, Livermore, W. Mojave, Gilroy-Coyote Lake, Shasta region, Great Valley, Morro Bay, Mono Craters-Long Valley, PACE, S. Sierras, LARSE 1 and 2, Loma Prieta, BASIX, San Francisco Peninsula and Parkfield. Our beta-version model is coarse (uniform 30 km horizontal and variable vertical gridding) but is able to image the principal features in previous separate regional models for northern and southern California, such as the high-velocity subducting Gorda Plate, upper to middle crustal velocity highs beneath the Sierra Nevada and much of the Coast Ranges, the deep low-velocity basins of the Great Valley, Ventura, and Los Angeles, and a high- velocity body in the lower crust underlying the Great Valley. The new state-wide model has improved areal coverage compared to the previous models, and extends to greater depth due to the data at large epicentral distances. We plan a series of steps to improve the model. We are enlarging and calibrating the active-source dataset as we obtain additional picks from investigators and perform quality control analyses on the existing and new picks. We will also be adding data from more quarry blasts, mainly in northern California, following an identification and calibration procedure similar to Lin et al. (2006). Composite event construction (Lin et al., in press) will be carried out for northern California for use in conventional tomography. A major contribution of the state-wide model is the identification of earthquakes yielding arrival times at both the Northern California Seismic

  15. Calibration of 3D Upper Mantle Structure in Eurasia Using Regional and Teleseismic Full Waveform Seismic Data

    Barbara Romanowicz; Mark Panning

    2005-04-23

    Adequate path calibrations are crucial for improving the accuracy of seismic event location and origin time, size, and mechanism, as required for CTBT monitoring. There is considerable information on structure in broadband seismograms that is currently not fully utilized. The limitations have been largely theoretical. the development and application to solid earth problems of powerful numerical techniques, such as the Spectral Element Method (SEM), has opened a new era, and theoretically, it should be possible to compute the complete predicted wavefield accurately without any restrictions on the strength or spatial extent of heterogeneity. This approach requires considerable computational power, which is currently not fully reachable in practice. We propose an approach which relies on a cascade of increasingly accurate theoretical approximations for the computation of the seismic wavefield to develop a model of regional structure for the area of Eurasia located between longitudes of 30 and 150 degrees E, and latitudes of -10 to 60 degrees North. The selected area is particularly suitable for the purpose of this experiment, as it is highly heterogeneous, presenting a challenge for calibration purposes, but it is well surrounded by earthquake sources and, even though they are sparsely distributed, a significant number of high quality broadband digital stations exist, for which data are readily accessible through IRIS (Incorporated Research Institutions for Seismology) and the FDSN (Federation of Digital Seismic Networks). The starting models used will be a combination of a-priori 3D models recently developed for this region, combining various geophysical and seismological data, and a major goal of this study will be to refine these models so as to fit a variety of seismic waveforms and phases.

  16. Improving Geologic and Engineering Models of Midcontinent Fracture and Karst-Modified Reservoirs Using New 3-D Seismic Attributes

    Susan Nissen; Saibal Bhattacharya; W. Lynn Watney; John Doveton

    2009-03-31

    Our project goal was to develop innovative seismic-based workflows for the incremental recovery of oil from karst-modified reservoirs within the onshore continental United States. Specific project objectives were: (1) to calibrate new multi-trace seismic attributes (volumetric curvature, in particular) for improved imaging of karst-modified reservoirs, (2) to develop attribute-based, cost-effective workflows to better characterize karst-modified carbonate reservoirs and fracture systems, and (3) to improve accuracy and predictiveness of resulting geomodels and reservoir simulations. In order to develop our workflows and validate our techniques, we conducted integrated studies of five karst-modified reservoirs in west Texas, Colorado, and Kansas. Our studies show that 3-D seismic volumetric curvature attributes have the ability to re-veal previously unknown features or provide enhanced visibility of karst and fracture features compared with other seismic analysis methods. Using these attributes, we recognize collapse features, solution-enlarged fractures, and geomorphologies that appear to be related to mature, cockpit landscapes. In four of our reservoir studies, volumetric curvature attributes appear to delineate reservoir compartment boundaries that impact production. The presence of these compartment boundaries was corroborated by reservoir simulations in two of the study areas. Based on our study results, we conclude that volumetric curvature attributes are valuable tools for mapping compartment boundaries in fracture- and karst-modified reservoirs, and we propose a best practices workflow for incorporating these attributes into reservoir characterization. When properly calibrated with geological and production data, these attributes can be used to predict the locations and sizes of undrained reservoir compartments. Technology transfer of our project work has been accomplished through presentations at professional society meetings, peer-reviewed publications

  17. 3D seismic analysis of gravity-driven and basement influenced normal fault growth in the deepwater Otway Basin, Australia

    Robson, A. G.; King, R. C.; Holford, S. P.

    2016-08-01

    We use three-dimensional (3D) seismic reflection data to analyse the structural style and growth of a normal fault array located at the present-day shelf-edge break and into the deepwater province of the Otway Basin, southern Australia. The Otway Basin is a Late Jurassic to Cenozoic, rift-to-passive margin basin. The seismic reflection data images a NW-SE (128-308) striking, normal fault array, located within Upper Cretaceous clastic sediments and which consists of ten fault segments. The fault array contains two hard-linked fault assemblages, separated by only 2 km in the dip direction. The gravity-driven, down-dip fault assemblage is entirely contained within the 3D seismic survey, is located over a basement plateau and displays growth commencing and terminating during the Campanian-Maastrichtian, with up to 1.45 km of accumulated throw (vertical displacement). The up-dip normal fault assemblage penetrates deeper than the base of the seismic survey, but is interpreted to be partially linked along strike at depth to major basement-involved normal faults that can be observed on regional 2D seismic lines. This fault assemblage displays growth initiating in the Turonian-Santonian and has accumulated up to 1.74 km of throw. Our detailed analysis of the 3D seismic data constraints post-Cenomanian fault growth of both fault assemblages into four evolutionary stages: [1] Turonian-Santonian basement reactivation during crustal extension between Australia and Antarctica. This either caused the upward propagation of basement-involved normal faults or the nucleation of a vertically isolated normal fault array in shallow cover sediments directly above the reactivated basement-involved faults; [2] continued Campanian-Maastrichtian crustal extension and sediment loading eventually created gravitational instability on the basement plateau, nucleating a second, vertically isolated normal fault array in the cover sediments; [3] eventual hard-linkage of fault segments in both fault

  18. 3D Seismic Reflection Imaging of Crustal Formation Processes on the East Pacific Rise, 9°57-42'N

    Purdy, G. M.; Mutter, J. C.; Carbotte, S. M.; Canales, J. P.; Nedimovic, M. R.; Carton, H.; Newman, K. R.; Marjanovic, M.; Xu, M.; Aghaei, O.; Stowe, L. C.

    2008-12-01

    Between June 29th and August 19th 2008 the research vessel Marcus G Langseth carried out its first multi- streamer 3D seismic reflection imaging cruise, MGL08-12, by conducting a program research on the East Pacific Rise centered around 9°50'N. The primary goals were to create an accurate 3D seismic reflection image of the magmatic-hydrothermal system at this Integrated Study Site of the Ridge2000 program by imaging the structure of the axial magma chamber (AMC) lid and oceanic crust at a resolution, accuracy, and scale comparable to seafloor observations. The vessel acquired data with four, 6-kilometer solid streamers each comprising 468 active channels deployed with a total separation of 450 meters. Four gun strings with total volume of 3300 cubic inches in two groups fired alternately provide the source for a shot spacing of 37.5 meters. This configuration yields eight CMP lines for each of the sail lines that were spaced 300 m apart, and a static bin size of 6.25 m × 37.5 m in the along-track and across-track directions, respectively, providing a nominal fold of 40. The cruise accomplished the acquisition of ~3,782 km of sail line data. There are 111 across axis lines that required 10 repeated lines and 14 infills. Average feathering during the cruise was 0° ± 5° (one standard deviation), with maximum values of up to 11°. This means that 18% of the total cross axis acquisition was needed for reshoots and infilling. A 25% multiplier on planned lines for a 3D grid is probably a useful figure to use in cruise planning and is fairly standard in the seismic industry. Data quality meets or exceeds industry standards. 3D coverage was achieved in two areas. The larger comprises a set of 93 equally spaced lines forming the 3D grid between 9°57'N and 9°42'N. This grid is made up of lines from all of racetracks #1 and #2 and the northern lines of racetrack#3 and covers two principal hydrothermal vent areas in a continuous fashion. The second 3D area is comprised

  19. Pseudo 3-D P wave refraction seismic monitoring of permafrost in steep unstable bedrock

    Krautblatter, Michael; Draebing, Daniel

    2014-02-01

    permafrost in steep rock walls can cause hazardous rock creep and rock slope failure. Spatial and temporal patterns of permafrost degradation that operate at the scale of instability are complex and poorly understood. For the first time, we used P wave seismic refraction tomography (SRT) to monitor the degradation of permafrost in steep rock walls. A 2.5-D survey with five 80 m long parallel transects was installed across an unstable steep NE-SW facing crestline in the Matter Valley, Switzerland. P wave velocity was calibrated in the laboratory for water-saturated low-porosity paragneiss samples between 20°C and -5°C and increases significantly along and perpendicular to the cleavage by 0.55-0.66 km/s (10-13%) and 2.4-2.7 km/s (>100%), respectively, when freezing. Seismic refraction is, thus, technically feasible to detect permafrost in low-porosity rocks that constitute steep rock walls. Ray densities up to 100 and more delimit the boundary between unfrozen and frozen bedrock and facilitate accurate active layer positioning. SRT shows monthly (August and September 2006) and annual active layer dynamics (August 2006 and 2007) and reveals a contiguous permafrost body below the NE face with annual changes of active layer depth from 2 to 10 m. Large ice-filled fractures, lateral onfreezing of glacierets, and a persistent snow cornice cause previously unreported permafrost patterns close to the surface and along the crestline which correspond to active seasonal rock displacements up to several mm/a. SRT provides a geometrically highly resolved subsurface monitoring of active layer dynamics in steep permafrost rocks at the scale of instability.

  20. Comparison of 3-D geological and geophysical investigation methods in boreholes KI-KR1 at Aeaenekoski Kivetty site and RO-KR3 at Kuhmo Romuvaara site

    The study is a part of the radioactive waste disposal investigations in Finland with the aim to compare three-dimensional geological and geophysical methods providing information on geologic fractures. Compared and described are the methods: core analysis, borehole television, dipmeter, borehole televiewer and differential flow measurements. (35 refs.)

  1. The Role of Faulting on the Growth of a Carbonate Platform: Evidence from 3D Seismic Analysis and Section Restoration

    Nur Fathiyah Jamaludin, Siti; Pubellier, Manuel; Prasad Ghosh, Deva; Menier, David; Pierson, Bernard

    2014-05-01

    Tectonics in addition to other environmental factors impacts the growth of carbonate platforms and plays an important role in shaping the internal architecture of the platforms. Detailed of faults and fractures development and healing in carbonate environment have not been explored sufficiently. Using 3D seismic and well data, we attempt to reconstruct the structural evolution of a Miocene carbonate platform in Central Luconia Province, offshore Malaysia. Luconia Province is located in the NW coast of Borneo and has become one of the largest carbonate factories in SE Asia. Seismic interpretations including seismic attribute analysis are applied to the carbonate platform to discern its sedimentology and structural details. Detailed seismic interpretations highlight the relationships of carbonate deposition with syn-depositional faulting. Branching conjugate faults are common in this carbonate platform and have become a template for reef growth, attesting lateral facies changes within the carbonate environments. Structural restoration was then appropriately performed on the interpreted seismic sections based on sequential restoration techniques, and provided images different from those of horizon flattening methods. This permits us to compensate faults' displacement, remove recent sediment layers and finally restore the older rock units prior to the fault motions. It allows prediction of platform evolution as a response to faulting before and after carbonate deposition and also enhances the pitfalls of interpretation. Once updated, the reconstructions allow unravelling of the un-seen geological features underneath the carbonate platform, such as paleo-structures and paleo-topography which in turn reflects the paleo-environment before deformations took place. Interestingly, sections balancing and restoration revealed the late-phase (Late Oligocene-Early Miocene) rifting of South China Sea, otherwise difficult to visualize on seismic sections. Later it is shown that

  2. A Late Paleozoic sill complex and related paleo-topography in the eastern North Sea analyzed using 3D seismic data

    Clausen, Ole Rønø; Andresen, Katrine Juul; Rasmussen, Jens Andreas

    2016-04-01

    In this paper, we utilize large igneous intrusions as a key to a detailed analysis and understanding of the late Paleozoic evolution of the Ringkøbing-Fyn High, an important structural element in the North West European Craton. The study takes advantage of high-quality 3D seismic data and boreholes to map the geometry and lateral distribution of intrusive sills cross-cutting the sedimentary strata at a low angle (transgressive sills). Our analysis shows that the transgressive sills most likely sourced the vast extrusion of volcanics, which covered most of the Early Permian Northern Basin and which is associated to the Skagerak-Centered Large Igneous Province (SCLIP). Furthermore, a geometrical analysis of the sills demonstrates that the magmatic source for the sills was located SE of the studied area, suggesting a correlation with geophysically inferred lower crust intrusions. Hence, we are in this study able to constrain the full magmatic system from the lower crust intrusions to the surface volcanics. Intrusion of the sills occurred prior to an Early Permian faulting event, which created rotated fault blocks outlining the present Ringkøbing-Fyn High. The sills exposed for erosion at the crest of the footwall in turn controlled the Late Permian paleo-topography and the distribution of the Zechstein evaporites due to the fact that they are harder to erode. Hence, we are able to demonstrate a topography controlled thickness variation of the Zechstein evaporites. The study furthermore emphasizes that an understanding of the deepest parts of the North Sea Basin is crucial when evaluating the potential for yet unrecognized hydrocarbon plays.

  3. Assessing the quality of earthquake source models using 3-D forward modelling of long-period seismic data

    Ferreira, A. M.; Vallée, M.; Lentas, K.

    2010-12-01

    Accurate earthquake point source parameters (e.g. seismic moment, depth and focal mechanism) provide key first-order information for detailed studies of the earthquake source process and for improved seismic and tsunami hazard evaluation. In order to objectively assess the quality of seismic source models, it is important to go beyond classical resolution/misfit checks. In particular, it is desirable to apply sophisticated modeling techniques to quantify uncertainties due to simplified theoretical formulations and/or Earth structure employed to build the source models. Moreover, it is important to verify how well the models explain data not used in their construction for a complete, quantitative assessment of the earthquake source models. In this study we compare the quality of the surface-wave Centroid Moment Tensor (CMT) method with that of the SCARDEC method, which is a new automated body-wave technique for the fast simultaneous determination of the seismic moment, focal mechanism, depth and source time functions of large earthquakes. We focus on the major shallow subduction earthquakes of the last 20 years, for which there are some systematic differences between SCARDEC and CMT source parameters, notably in fault dip angle and moment magnitude. Because the SCARDEC method is based on body-wave deconvolution using ray methods in a 1D Earth model, we test how well SCARDEC source parameters explain long-period seismic data (surface waves and normal modes) compared to the CMT method. We calculate theoretical seismograms using two forward modelling techniques (full ray theory and spectral element method) to simulate the long-period seismic wavefield for the 3D Earth model S20RTS combined with the crust model CRUST2.0, and for two point source models: (i) the SCARDEC model; and (ii) the Global CMT model. We compare the synthetic seismograms with real broadband data from the FDSN for the major subduction earthquakes of the last 20 years. We show that SCARDEC source

  4. 3D seismic expression of fluid migration and mud remobilization on the Gjallar Ridge, offshore mid-Norway

    Hansen, J.P.V.; Cartwright, J.A.; Huuse, M.;

    2005-01-01

    anomalies and possible mud volcanoes at the base Pleistocene indicating their long-term significance as vertical fluid conduits. Type C structures comprise discrete mound features that seem to jack up the Top Palaeocene (Top Brygge) horizon. These are similar to hydrothermal mounds found elsewhere on the......This paper presents a three-dimensional (3D) seismic analysis of sediment remobilization and fluid migration in a 2000-km2 area above the Gjallar Ridge located in the Vøring Basin, offshore Norway. Three distinct types of mounded structures have been identified as resulting from focused fluid....../gas migration and associated mud remobilization and intrusion. Type A structures are gently mounded, and we infer that these structures formed because of in situ remobilization of Middle Eocene to LowerMiddle Oligocene fine-grained sediments in response to fluid and minor sediment injection via deep...

  5. Seismic imaging in the eastern Scandinavian Caledonides: siting the 2.5 km deep COSC-2 borehole, central Sweden

    Juhlin, Christopher; Hedin, Peter; Gee, David G.; Lorenz, Henning; Kalscheuer, Thomas; Yan, Ping

    2016-05-01

    The Collisional Orogeny in the Scandinavian Caledonides (COSC) project, a contribution to the International Continental Scientific Drilling Program (ICDP), aims to provide a deeper understanding of mountain belt dynamics. Scientific investigations include a range of topics, from subduction-related tectonics to the present-day hydrological cycle. COSC investigations and drilling activities are focused in central Scandinavia, where rocks from the middle to lower crust of the orogen are exposed near the Swedish-Norwegian border. Here, rock units of particular interest occur in the Seve Nappe Complex (SNC) of the so-called Middle Allochthon and include granulite facies migmatites (locally with evidence of ultra-high pressures) and amphibolite facies gneisses and mafic rocks. This complex overlies greenschist facies metasedimentary rocks of the dolerite-intruded Sarv Nappes and underlying, lower grade Jamtlandian Nappes (Lower Allochthon). Reflection seismic profiles have been an important component in the activities to image the subsurface structure in the area. Subhorizontal reflections in the upper 1-2 km are underlain and interlayered with strong west- to northwest-dipping reflections, suggesting significant east-vergent thrusting. Two 2.5 km deep fully cored boreholes are a major component of the project, which will improve our understanding of the subsurface structure and tectonic history of the area. Borehole COSC-1 (IGSN: http://hdl.handle.net/10273/ICDP5054EEW1001), drilled in the summer of 2014, targeted the subduction-related Seve Nappe Complex and the contact with the underlying allochthon. The COSC-2 borehole will be located further east and will investigate the lower grade, mainly Cambro-Silurian rocks of the Lower Allochthon, the Jamtlandian decollement, and penetrate into the crystalline basement rocks to identify the source of some of the northwest-dipping reflections. A series of high-resolution seismic profiles have been acquired along a composite ca

  6. Investigation of drilling failure of Well A1, E-Field, onshore Niger Delta, Nigeria, using 3-D seismic data

    Akinmosin, A.; Oladele, S.; Oriade, O. F.

    2016-02-01

    This study aimed at investigating reasons for failure of Well A1 that is surrounded by hydrocarbon discoveries in onshore Niger delta with a view to propose optimal location for a new well through interpretation of new 3-D seismic data. Sands encountered by Well A1 were delineated and tied to seismic. Structural closure was mapped and reservoirs at various depths were stacked and sectioned. Porosity, Net to Gross, and Gross Rock Volume of the reservoirs were computed. Well A1 was correlated to a nearby Well K4 and a good correlation was observed. A fault assisted multi reservoirs Prospect-E with south-westerly shift with depth was delineated on the hanging wall of structure building E-Fault whose closing contours is expected to trap hydrocarbon. Petrophysical properties of the reservoirs range from fair to good. Well A1 either perforated prospect-E beneath the oil water contact, completely missed prospect-E or punctured the wet foot wall of E-fault. Consequently, Well A1 could not impact the objective sands and only able to produce water. Well A1 failed because of wrong surface positioning which unsuccessfully targeted the shifting reservoirs. A successful exploratory well in E-Field would be a gently south-westerly deviated well whose vertical section would encounter the shallower sands and deviated section targeting the deeper sands with surface location at about 1 km southeast of Well A1.

  7. Effects of eccentricity and order of vibration modes on the inelastic seismic response of 3D steel structures

    P. Sharifi, Naser; Sakulich, Aaron R.

    2014-04-01

    In torsionally coupled buildings, the total response of the structure is the result of the translational displacement of the story's center of stiffness and the displacement due to the roof's rotation. In structures with high eccentricity, the effect of the floor's rotation in the total response is considerable. The order of vibration modes is another important parameter that changes the contribution of the different translational and rotational modes in the total response. To explore the effects of eccentricity and the order of vibration modes on the total response, a number of 3-D steel moment-resistant frames with 4, 8, and 12 stories, with different eccentricities and plans, were considered. The structures were subjected to bidirectional seismic inputs so that their peak ground accelerations were scaled to 0.4g, 0.6g, and 0.8g. Increasing the eccentricity of the structure increases the participation of rotation in the total response. Furthermore, in torsionally flexible structures, where the first or second mode of vibration is a torsional mode, the contribution of the floor's rotation can be even greater. In some cases, the displacement of exterior columns is primarily the result of the floor's rotation. This suggests that to efficiently dampen the seismic displacement of such structures, the rotational mode of the building should be controlled.

  8. Method for identifying subsurface fluid migration and drainage pathways in and among oil and gas reservoirs using 3-D and 4-D seismic imaging

    Anderson, Roger N.; Boulanger, Albert; Bagdonas, Edward P.; Xu, Liqing; He, Wei

    1996-01-01

    The invention utilizes 3-D and 4-D seismic surveys as a means of deriving information useful in petroleum exploration and reservoir management. The methods use both single seismic surveys (3-D) and multiple seismic surveys separated in time (4-D) of a region of interest to determine large scale migration pathways within sedimentary basins, and fine scale drainage structure and oil-water-gas regions within individual petroleum producing reservoirs. Such structure is identified using pattern recognition tools which define the regions of interest. The 4-D seismic data sets may be used for data completion for large scale structure where time intervals between surveys do not allow for dynamic evolution. The 4-D seismic data sets also may be used to find variations over time of small scale structure within individual reservoirs which may be used to identify petroleum drainage pathways, oil-water-gas regions and, hence, attractive drilling targets. After spatial orientation, and amplitude and frequency matching of the multiple seismic data sets, High Amplitude Event (HAE) regions consistent with the presence of petroleum are identified using seismic attribute analysis. High Amplitude Regions are grown and interconnected to establish plumbing networks on the large scale and reservoir structure on the small scale. Small scale variations over time between seismic surveys within individual reservoirs are identified and used to identify drainage patterns and bypassed petroleum to be recovered. The location of such drainage patterns and bypassed petroleum may be used to site wells.

  9. Land 3D-seismic data: Preprocessing quality control utilizing survey design specifications, noise properties, normal moveout, first breaks, and offset

    Raef, A.

    2009-01-01

    The recent proliferation of the 3D reflection seismic method into the near-surface area of geophysical applications, especially in response to the emergence of the need to comprehensively characterize and monitor near-surface carbon dioxide sequestration in shallow saline aquifers around the world, justifies the emphasis on cost-effective and robust quality control and assurance (QC/QA) workflow of 3D seismic data preprocessing that is suitable for near-surface applications. The main purpose of our seismic data preprocessing QC is to enable the use of appropriate header information, data that are free of noise-dominated traces, and/or flawed vertical stacking in subsequent processing steps. In this article, I provide an account of utilizing survey design specifications, noise properties, first breaks, and normal moveout for rapid and thorough graphical QC/QA diagnostics, which are easy to apply and efficient in the diagnosis of inconsistencies. A correlated vibroseis time-lapse 3D-seismic data set from a CO2-flood monitoring survey is used for demonstrating QC diagnostics. An important by-product of the QC workflow is establishing the number of layers for a refraction statics model in a data-driven graphical manner that capitalizes on the spatial coverage of the 3D seismic data. ?? China University of Geosciences (Wuhan) and Springer-Verlag GmbH 2009.

  10. Land 3D-Seismic Data: Preprocessing Quality Control Utilizing Survey Design Specifications, Noise Properties, Normal Moveout, First Breaks, and Offset

    Abdelmoneam Raef

    2009-01-01

    The recent proliferation of the 3D reflection seismic method into the near-surface area of geophysical applications, especially in response to the emergence of the need to comprehensively characterize and monitor near-surface carbon dioxide sequestration in shallow saline aquifers around the world, Justifies the emphasis on cost-effective and robust quality control and assurance (QC/QA) workflow of 3D seismic data preprocessing that is suitable for near-surface applications. The main purpose of our seismic data preprocessing QC is to enable the use of appropriate header information, data that are free of noise-dominated traces, and/or flawed vertical stacking in subsequent processing steps. In this article, I provide an account of utilizing survey design specifications, noise properties, first breaks, and normal moveout for rapid and thorough graphical QC/QA diagnostics, which are easy to apply and efficient in the diagnosis of inconsistencies. A correlated vibroseis time-lapse 3D-seismic data set from n CO2-flood monitoring survey is used for demonstrating QC dlagnostles. An Important by-product of the QC workflow is establishing the number of layers for n refraction statics model in a data-driven graphical manner that capitalizes on the spatial coverage of the 3D seismic data.

  11. Scientific results from the deepened Lopra-1 borehole, Faroe Islands: Borehole seismic studies of a volcanic succession from the Lopra-1/1A borehole in the Faroe Islands, northern North Atlantic

    Cowper, David

    2006-07-01

    Full Text Available Extruded basalt flows overlying sedimentary sequences present a challenge to hydrocarbon exploration using reflection seismic techniques. The Lopra-1/1A re-entry well on the Faroese island of Suðuroy allowed us to study the seismic characteristics of a thick sequence of basalt flows from well logs and borehole seismic recordings. Data acquired during the deepening operation in 1996 are presented here.The re-entry well found that the seismic event at 2340 m, prognosed from the pre-drill Vertical Seismic Profile (VSP as a decrease in impedance, was not base basalt and the deepened well remainedwithin the lower series basalts. Nonetheless, compressional and shear sonic logs and a density log were recorded over the full open hole interval. These allowed a firm tie to be made with the reflectedwavefield from a new VSP. The sonic logs show a compressional to shear wavespeed ratio of 1.84 which is almost constant with depth. Sonic compressional wavespeeds are 3% higher than seismicvelocities, suggesting dispersion in the basalt flows. Azimuthal anisotropy was weakly indicated by the shear sonic log but its orientation is consistent with the directions of mapped master joints in the vicinity of the well.The VSP downgoing compressional wavelet shows good persistence, retaining a dominant period of 28 ms at 3510 m depth. Average vertical velocity is 5248 m/s, higher than previously reported.Attenuation can largely be modelled by geometrical spreading and scattering loss, consistent with other studies. Within the piled flows, the effective Q from scattering is about 35. Elastic layeredmedium modelling shows some hope that a mode-converted shear wave may be observed at moderate offsets. Like its predecessor, the 1996 VSP indicates a decrease in impedance below the final depth ofthe well. However, it is unlikely to be basement or sediment and is probably an event within the volcanic sequence.

  12. Contrasting fluvial styles across the mid-Pleistocene climate transition in the northern shelf of the South China Sea: Evidence from 3D seismic data

    Zhuo, Haiteng; Wang, Yingmin; Shi, Hesheng; He, Min; Chen, Weitao; Li, Hua; Wang, Ying; Yan, Weiyao

    2015-12-01

    Multiple successions of buried fluvial channel systems were identified in the Quaternary section of the mid-shelf region of the northern South China Sea, providing a new case study for understanding the interplay between sea level variations and climate change. Using three commercial 3D seismic surveys, accompanied by several 2D lines and a few shallow boreholes, the sequence stratigraphy, seismic geomorphology and stratal architecture of these fluvial channels were carefully investigated. Based on their origin, dimensions, planform geometries and infill architectures, six classes of channel systems, from Class 1 to Class 6, were recognized within five sequences of Quaternary section (SQ1 to SQ5). Three types of fluvial systems among them are incised in their nature, including the trunk incised valleys (Class 1), medium incised valleys (Class 2) and incised tributaries (Class 3). The other three types are unincised, which comprise the trunk channels (Class 4), lateral migrating channels (Class 5) and the stable channels (Class 6). The trunk channels and/or the major valleys that contain braided channels at their base are hypothesized to be a product of deposition from the "big rivers" that have puzzled the sedimentologists for the last decade, providing evidence for the existence of such rivers in the ancient record. Absolute age dates from a few shallow boreholes indicate that the landscapes that were associated with these fluvial systems changed significantly near the completion of the mid-Pleistocene climate transition (MPT), which approximately corresponds to horizon SB2 with an age of ˜0.6 Ma BP. Below SB2, the Early Pleistocene sequence (SQ1) is dominated by a range of different types of unincised fluvial systems. Evidence of incised valleys is absent in SQ1. In contrast, extensive fluvial incision occurred in the successions above horizon SB2 (within SQ2-SQ5). Although recent studies call for increased incision being a product of climate-controlled increase

  13. A seismic modeling analysis of wide and narrow 3D observation systems for channel sand bodies%河道砂体宽/窄方位三维观测系统地震物理模型分析

    狄帮让; 徐秀仓; 魏建新

    2008-01-01

    The effect of the wide and narrow azimuth 3D observation systems on seismic imaging precision is becoming a hot area for studies of high precision 3D seismic acquisition methods in recent years. In this paper we utilize 3D physical seismic modeling experiments. A 3D channel sand body physical seismic model is constructed and two acquisition systems are designed with wide azimuth (16 lines) and narrow azimuth (8 lines) to model 3D seismic data acquisition and processing seismic work flows. From analysis of migrated time slice data with high quality and small size, we conclude that when the overlying layers are smooth and lateral velocities have little change, both wide and narrow azimuth observation systems in 3D acquisition can be used for obtaining high precision imaging and equivalent resolution of the channel sand body.

  14. A 3D Seismic Velocity Model Offshore Southern California from Ambient Noise Tomography of the ALBACORE OBS Array

    Kohler, M. D.; Bowden, D. C.; Tsai, V. C.; Weeraratne, D. S.

    2015-12-01

    The Pacific-North America plate boundary in Southern California extends far west of the coastline, and a 12-month ocean bottom seismometer (OBS) array spanned the western side of the plate boundary to image lithospheric seismic velocities. Velocities are modeled through stacked cross correlations of ambient noise data. Twelve months of continuous data were used from 22 OBS stations and ~30 coastal and island Southern California Seismic Network stations. Particular attention has been paid to improving signal-to-noise ratios in the noise correlations with OBS stations by removing the effects of instrument tilt and infragravity waves. Different applications of preprocessing techniques allow us to distinguish the fundamental and first higher order Rayleigh modes, especially in deep water OBS pairs where the water layer dominates crustal sensitivity of the fundamental mode. Standard time domain and frequency domain methods are used to examine surface wave dispersion curves for group and phase velocities between 5 and 50 second periods, and these are inverted for 3D velocity structure. The results define the transition in three dimensions from continental lithospheric structure in the near-shore region to oceanic structure west of the continental borderland. While the most prominent features of the model relate to thinning of the crust west of the Patton Escarpment, other notable anomalies are present north-to-south throughout the continental borderland and along the coast from the Los Angeles Basin to the Peninsular Ranges. The velocity model will help describe the region's tectonic history, as well as provide new constraints for determination of earthquake relocations and rupture styles.

  15. Newly discovered abundant fluid seep indicators off southern Costa Rica, imaged from overlapping multibeam swaths and 3D seismic data

    Kluesner, J. W.; Silver, E. A.; Gibson, J. C.; Bangs, N. L.; McIntosh, K.; von Huene, R.; Orange, D.; Ranero, C. R.

    2012-12-01

    Offshore southern Costa Rica we have identified 161 potential fluid seepage sites on the shelf and slope regions within an 11 x 55 km strip where no fluid indicators had been reported previously using conventional deep-water mutlibeam bathymetry (100 m grid cell size) and deep towed side scan sonar. Evidence includes large and small pockmarks, mounds, ridges, and slope failure features with localized anomalous high-amplitude backscatter strength. The majority of seepage indicators are associated with shallow sub-bottom reversed polarity bright spots and flat spots imaged within the CRISP 3D seismic grid. Data were collected ~50 km west of Osa Peninsula, Costa Rica onboard the R/V Marcus G. Langseth during the spring of 2011. We obtained EM122 multibeam data using fixed, closely spaced receiver beams and 9-10 times swath overlap, which greatly improved the signal-to-noise ratio and sounding density and allowed for very small grid and mosaic cell sizes (2-10 m). A gas plume in the water column, seen on a 3.5 kHz profile, is located along a fault trace and above surface and subsurface seep indicators. Fluid indicators on the outer shelf occur largely on a dense array of faults, some of which cut through the reflective basement. Seismic flat spots commonly underlie axes of large anticlines on the shelf and slope. Pockmarks are also located at the foot of mid-slope canyons, very near to the upper end of the BSR. These pockmarks appear to be associated with canyon abandonment and folded beds that channel fluids upward, causing hydrate instability. Our findings suggest that significant amounts of methane are venting into ocean and potentially into the atmosphere across the heavily deformed shelf and slope of Costa Rica.

  16. The internal geometry of salt structures - A first look using 3D seismic data from the Zechstein of the Netherlands

    Van Gent, Heijn; Urai, Janos L.; de Keijzer, Martin

    2011-03-01

    We present a first look at the large-scale, complexly folded and faulted internal structure of Zechstein salt bodies in NW Europe using 3D reflection seismic reflection data from two surveys on the Groningen High and the Cleaver Bank High. We focus on a relatively brittle, folded and boudinaged, claystone-carbonate-anhydrite layer (the Z3 stringer) enclosed in ductile salt. A first classification of the structures is presented and compared with observations from salt mines and analogue and numerical models. Z3 stringers not only are reservoirs for hydrocarbons but can also present a serious drilling problem in some areas. Results of this study could provide the basis for better prediction of zones of drilling problems. More generally, the techniques presented here can be used to predict the internal structure of salt bodies, to estimate the geometry of economic deposits of all kinds and locate zones suitable for storage caverns. Structures observed include an extensive network of zones with increased thickness of the stringer. These we infer to have formed by early diagenesis, karstification, gravitational sliding and associated local sedimentation. Later, this template was deformed into large-scale folds and boudins during salt tectonics. Salt flow was rarely plane strain, producing complex fold and boudin geometries. Deformation was further complicated by the stronger zones of increased thickness, which led to strongly non-cylindrical structures. We present some indications that the thicker zones also influence the locations of later suprasalt structures, suggesting a feedback between the early internal evolution of this salt giant and later salt tectonics. This study opens the possibility to study the internal structure of the Zechstein and other salt giants in 3D using this technique, exposing a previously poorly known structure which is comparable in size and complexity to the internal parts of some orogens.

  17. A radial 3-D seismic survey at Exxon's Grand Isle 16 field, Gulf of Mexico

    Beebe, R.R.; Harrison, W.K. (Exxon Co., New Orleans, LA (USA))

    1990-05-01

    Grand Isle 16 field is one of several large salt diapirs that occur along the Bay Marchand salt ridge located along the southern boundary of the Terrebonne trough. Discovered in 1948, Exxon's oldest field in the Gulf of Mexico has produced 268 MB0 and 417 GCFG from upper Miocene sands. Over 400 wells have been drilled for hydrocarbons found in three major plays: (1) updip truncation of steeply dipping reservoirs by salt, (2) subunconformity accumulations, and, (3) off-structure stratigraphic traps. Despite extensive drilling, significant potential remains to be evaluated. The authors decided that a 3-D (three-dimensional) seismic survey is the best way to delineate the field's remaining potential. A rectangular survey with lines shot using streamers was eliminated because of surface obstacles, high cost, and inefficient imaging where lines interesect the salt face and steeply dipping beds at an oblique angle. As an alternative, a radial survey was designed whereby lines radiate from a central point over the dome with infill lines added when predetermined separation between lines is reached. Following extensive 2-D (two-dimensional) testing, shooting with bay cables commenced in February 1988, and was completed in October 1988. The processed data set consists of radial lines, circumferential lines, and time slices migrated using a two-pass technique. A regridded cube including inlines migrated with a one-pass (true 3-D) method is also included. This data became available for interpretation in July 1989, and has accomplished the goals of reducing acquisition cost and defining steeply dipping beds near the salt face.

  18. Characterization of the Hontomín Research Facility for Geological Storage of CO2: 3D Seismic Imaging Results

    Alcalde, J.; Martí, D.; Juhlin, C.; Malehmir, A.; Calahorrano, A.; Ayarza, P.; Pérez-Estaún, A.; Carbonell, R.

    2012-04-01

    A technological research facility dedicated to the underground geological storage of CO2 is currently being developed by the Spanish research program on Carbon Capture and Storage (CCS) in Hontomin (Burgos). This research program is being developed by the CIUDEN Foundation, an initiative launched by 3 Spanish state departments (Science & Innovation, Environment and Industry). An extensive multidisciplinary site characterization phase has been carried out, including a multiseismic data acquisition experiment. Within this effort, a 36 km2 3D seismic reflection survey was acquired in the summer of 2010. Its aim was to provide high resolution images of the subsurface of the storage complex, as well as to provide a baseline model for all the disciplines involved in the project. The target reservoir is a saline aquifer located at 1400 m, approximately, within Lower Jurassic carbonates (Lias). The main seal is formed by inter-layered marls and marly limestones of Early to Middle Jurassic age (Dogger and Lias). The main acquisition characteristics of the survey included (1) a mixed source of vibroseis and explosives with 74% and 26% of each used, respectively, (2) 5000 source points distributed along 22 source lines (separated 250 m) and (3) 22 lines of receivers (separated 275 m). Shot and receiver spacing along the source and receiver lines was 25 m, resulting in a nominal CDP-fold of 36 for 13 m2 bins. The 3D-data have been fully processed to post stack migration. The most critical processing steps included static correction calculations, time variant frequency filtering, rms velocity analysis, F-XY deconvolution, dip move-out correction, residual statics calculations and post stack migration. The final high-resolution 3D-volume shows the shape and depth of the primary reservoir-seal system, the main faults of the area and the secondary reservoir-seal sequence. It allows us to characterize the main tectonic structure of the dome complex, the fault system of the area and

  19. Site study plan for EDBH (Engineering Design Boreholes) seismic surveys, Deaf Smith County site, Texas: Revision 1

    Hume, H.

    1987-12-01

    This site study plan describes seismic reflection surveys to run north-south and east-west across the Deaf Smith County site, and intersecting near the Engineering Design Boreholes (EDBH). Both conventional and shallow high-resolution surveys will be run. The field program has been designed to acquire subsurface geologic and stratigraphic data to address information/data needs resulting from Federal and State regulations and Repository program requirements. The data acquired by the conventional surveys will be common-depth- point, seismic reflection data optimized for reflection events that indicate geologic structure near the repository horizon. The data will also resolve the basement structure and shallow reflection events up to about the top of the evaporite sequence. Field acquisition includes a testing phase to check/select parameters and a production phase. The field data will be subjected immediately to conventional data processing and interpretation to determine if there are any anamolous structural for stratigraphic conditions that could affect the choice of the EDBH sites. After the EDBH's have been drilled and logged, including vertical seismic profiling, the data will be reprocessed and reinterpreted for detailed structural and stratigraphic information to guide shaft development. The shallow high-resulition seismic reflection lines will be run along the same alignments, but the lines will be shorter and limited to immediate vicinity of the EDBH sites. These lines are planned to detect faults or thick channel sands that may be present at the EDBH sites. 23 refs. , 7 figs., 5 tabs.

  20. Site study plan for EDBH [Engineering Design Boreholes] seismic surveys, Deaf Smith County site, Texas: Revision 1

    This site study plan describes seismic reflection surveys to run north-south and east-west across the Deaf Smith County site, and intersecting near the Engineering Design Boreholes (EDBH). Both conventional and shallow high-resolution surveys will be run. The field program has been designed to acquire subsurface geologic and stratigraphic data to address information/data needs resulting from Federal and State regulations and Repository program requirements. The data acquired by the conventional surveys will be common-depth- point, seismic reflection data optimized for reflection events that indicate geologic structure near the repository horizon. The data will also resolve the basement structure and shallow reflection events up to about the top of the evaporite sequence. Field acquisition includes a testing phase to check/select parameters and a production phase. The field data will be subjected immediately to conventional data processing and interpretation to determine if there are any anamolous structural for stratigraphic conditions that could affect the choice of the EDBH sites. After the EDBH's have been drilled and logged, including vertical seismic profiling, the data will be reprocessed and reinterpreted for detailed structural and stratigraphic information to guide shaft development. The shallow high-resulition seismic reflection lines will be run along the same alignments, but the lines will be shorter and limited to immediate vicinity of the EDBH sites. These lines are planned to detect faults or thick channel sands that may be present at the EDBH sites. 23 refs. , 7 figs., 5 tabs

  1. Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect

    Frary, R.; Louie, J. [UNR; Pullammanappallil, S. [Optim; Eisses, A.

    2016-08-01

    Roxanna Frary, John N. Louie, Sathish Pullammanappallil, Amy Eisses, 2011, Preliminary 3d depth migration of a network of 2d seismic lines for fault imaging at a Pyramid Lake, Nevada geothermal prospect: presented at American Geophysical Union Fall Meeting, San Francisco, Dec. 5-9, abstract T13G-07.

  2. 3D high resolution mineral phase distribution and seismic velocity structure of the transition zone: predicted by a full spherical-shell compressible mantle convection model

    Geenen, T.; Heister, T.; Van Den Berg, A. P.; Jacobs, M.; Bangerth, W.

    2011-12-01

    We present high resolution 3D results of the complex mineral phase distribution in the transition zone obtained by numerical modelling of mantle convection. We extend the work by [Jacobs and van den Berg, 2011] to 3D and illustrate the efficiency of adaptive mesh refinement for capturing the complex spatial distribution and sharp phase transitions as predicted by their model. The underlying thermodynamical model is based on lattice dynamics which allows to predict thermophysical properties and seismic wave speeds for the applied magnesium-endmember olivine-pyroxene mineralogical model. The use of 3D geometry allows more realistic prediction of phase distribution and seismic wave speeds resulting from 3D flow processes involving the Earth's transition zone and more significant comparisons with interpretations from seismic tomography and seismic reflectivity studies aimed at the transition zone. Model results are generated with a recently developed geodynamics modeling application based on dealII (www.dealii.org). We extended this model to incorporate both a general thermodynamic model, represented by P,T space tabulated thermophysical properties, and a solution strategy that allows for compressible flow. When modeling compressible flow in the so called truncated anelastic approximation framework we have to adapt the solver strategy that has been proven by several authors to be highly efficient for incompressible flow to incorporate an extra term in the continuity equation. We present several possible solution strategies and discuss their implication in terms of robustness and computational efficiency.

  3. Hypocenter relocation using a fast grid search method and a 3-D seismic velocity model for the Sumatra region

    Nugroho, Hendro [Study Program of Earth Sciences, Faculty of Earth Sciences and Technology, Institute of Technology Bandung, Jl. Ganesha No. 10, Bandung 40132, Indonesia and Meteorological, Climatological, and Geophysical Agency, Jl. Angkasa 1 No. 2, Kemayoran, Jakar (Indonesia); Widiyantoro, Sri [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technology Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia); Nugraha, Andri Dian [Global Geophysics Research Group, Faculty of Mining and Petroleum Engineering, Institute of Technologyc Bandung, Jl. Ganesha No. 10, Bandung 40132 (Indonesia)

    2013-09-09

    Determination of earthquake hypocenter in Indonesia conducted by the Meteorological, Climatological, and Geophysical Agency (MCGA) has still used a 1-D seismic velocity model. In this research, we have applied a Fast Grid Search (FGM) method and a 3-D velocity model resulting from tomographic imaging to relocate earthquakes in the Sumatran region. The data were taken from the MCGA data catalog from 2009 to 2011 comprising of subduction zone and on land fault earthquakes with magnitude greater than 4 Mw. Our preliminary results show some significant changes in the depths of the relocated earthquakes which are in general deeper than the depths of hypocenters from the MCGA data catalog. The residual times resulting from the relocation process are smaller than those prior to the relocation. Encouraged by these results, we will continue to conduct hypocenter relocation for all events from the MCGA data catalog periodically in order to produce a new data catalog with good quality. We hope that the new data catalog will be useful for further studies.

  4. Hypocenter relocation using a fast grid search method and a 3-D seismic velocity model for the Sumatra region

    Determination of earthquake hypocenter in Indonesia conducted by the Meteorological, Climatological, and Geophysical Agency (MCGA) has still used a 1-D seismic velocity model. In this research, we have applied a Fast Grid Search (FGM) method and a 3-D velocity model resulting from tomographic imaging to relocate earthquakes in the Sumatran region. The data were taken from the MCGA data catalog from 2009 to 2011 comprising of subduction zone and on land fault earthquakes with magnitude greater than 4 Mw. Our preliminary results show some significant changes in the depths of the relocated earthquakes which are in general deeper than the depths of hypocenters from the MCGA data catalog. The residual times resulting from the relocation process are smaller than those prior to the relocation. Encouraged by these results, we will continue to conduct hypocenter relocation for all events from the MCGA data catalog periodically in order to produce a new data catalog with good quality. We hope that the new data catalog will be useful for further studies

  5. 3D seismic, geochemical and biostratigraphical analysis of Paleogene remobilized sand in the Norwegian-Danish Basin

    Andresen, Katrine Juul; Rønø Clausen, Ole; Heilmann-Clausen, Claus; Friis, Henrik

    2013-04-01

    This study describes remobilized Paleogene sand occurring on the hanging-wall segment north of the major D-1 normal fault in the Norwegian-Danish Basin, eastern North Sea. The remobilized sand is observed on 3D seismic data in fine-grained Eocene host-strata as cross-cutting reflections with a typical tabular, V-shaped or wing-like geometry in the seismic cross-sections and a pronounced jack-up of the overlying succession onto which onlap can be observed. In map view the remobilized sand in certain areas have a channel-like appearance. The seismic observations indicate that the sand has a remobilized origin which may be partly depositional. Particularly the observed wings and jack-up on the seismic cross-sections indicate remobilization which potentially could be generated by two different processes: a) remobilization of depositional channel sand resulting in the formation of injected wings along the sides of the channel, or b) injection of remobilized sand from the deeper Paleocene strata causing jack-up and typically V-shaped intrusions. Injection of Paleocene sand into Eocene host strata is a well-known phenomenon from the nearby Paleogene Siri Canyon located c. 15 km north of the study area. In order to acquire more information about the intrusions a geochemical study and a detailed biostratigraphical dating of cuttings and sidewall core samples from the Floki-1 well was carried out. The Floki-1 well penetrates the remobilized sand and was drilled to test an apparent 4-way closure on prospect Eocene sand which by then was interpreted to be 100 % depositional. The geochemical study of the samples from the sand identified the Floki-sandstone as a very fine grained sand and silt with a matrix of very angular silt grains. The sand does not contain clays. The matrix appears to have formed by crushing of the sand grains. Thus, heavy minerals appear to have disintegrated by crushing but still most parts of the mineral grain is found together. Glauconite grains are

  6. Mapping the North Sea base-Quaternary: using 3D seismic to fill a gap in the geological record

    Lamb, Rachel; Huuse, Mads; Stewart, Margaret; Brocklehurst, Simon H.

    2014-05-01

    The identification and mapping of the base-Quaternary boundary in the central parts of the North Sea is problematic due to the change from an unconformable transition between Pliocene and Pleistocene deltaic deposits in the southern North Sea to a conformable one further north (Sejrup et al 1991; Gatliff et al 1994). The best estimates of the transition use seismic reflection data to identify a 'crenulated reflector' (Buckley 2012), or rely on correlating sparse biostratigraphy (Cameron et al 1987). Recent integration of biostratigraphy, pollen analysis, paleomagnetism and amino acid analysis in the Dutch and Danish sectors (Rasmussen et al 2005; Kuhlmann et al 2006) allows greater confidence in the correlation to a regional 3D seismic dataset and show that the base-Quaternary can be mapped across the entire basin. The base-Quaternary has been mapped using the PGS MegaSurvey dataset from wells in the Danish Sector along the initially unconformable horizon and down the delta front into the more conformable basin giving a high degree of confidence in the horizon pick. The mapped horizon is presented here alongside the difference between this new interpretation and the previously interpreted base-Quaternary (Buckley 2012). The revised base-Quaternary surface reaches a depth of 1248 ms TWT or approximately 1120 m (assuming average velocity of 1800 m/s) showing an elongate basin shape that follows the underlying structure of the Central Graben. The difference between the revised base-Quaternary and the traditional base-Quaternary reaches a maximum of over 600 ms TWT or approximately 540 m in the south-west with over 300 ms TWT or approximately 270 m at the Josephine well (56° 36.11'N, 2° 27.09'E) in the centre of the basin. Mapping this new base-Quaternary allows for the interpretation of the paleo-envionrment during the earliest Quaternary. Seismic attribute analysis indicates a deep water basin with sediment deposition from multiple deltas and redistribution by deep

  7. Anisotropic 3D Modeling for Long Offset VSP Survey Design

    Today's seismic techniques allow the geoscientist to do the interpretation more quantitatively. AVO and anisotropy measurements are the examples of DHI (Direct Hydrocarbon Indication). These measurements can be done accurately using long offset borehole seismic survey such as walk away VSP, having the geophones located down hole close to the target formation. This paper will show the importance 3D seismic modeling prior to the survey, by simulating the seismic wave propagation in three-dimensional volume filled with continuous material properties. This pre-survey modeling can help us suppressing the uncertainties and narrowing the error bars on the real survey. Some examples from offshore Nigeria showed dramatic geometrical differences between ordinary 2D compared to 3D observations Assumption that the seismic wave travels in 2D plane is not always acceptable for survey design. The examples also demonstrated the ability to observe some critical information such as the limit of incidence angle, compromise between resolution and image coverage, effects of velocity anomalies, anisotropy and dipping formations on lateral coverage. Fluid effect in 3D modeling will also be discussed here. Amplitude anomalies are predicted by replacing different type of fluids effect in the target reservoirs, as well as various types of AVO classes. A well-prepared long offset VSP survey is very critical to provide us high quality and high accuracy information that can be used to calibrate and optimise the full 3D seismic processing and interpretation in the area. This process is known as Well Driven Seismic (WDS)

  8. Experimental evidence for seismically initiated gas bubble nucleation and growth in groundwater as a mechanism for coseismic borehole water level rise and remotely triggered seismicity

    Crews, Jackson B.; Cooper, Clay A.

    2014-09-01

    Changes in borehole water levels and remotely triggered seismicity occur in response to near and distant earthquakes at locations around the globe, but the mechanisms for these phenomena are not well understood. Experiments were conducted to show that seismically initiated gas bubble growth in groundwater can trigger a sustained increase in pore fluid pressure consistent in magnitude with observed coseismic borehole water level rise, constituting a physically plausible mechanism for remote triggering of secondary earthquakes through the reduction of effective stress in critically loaded geologic faults. A portion of the CO2 degassing from the Earth's crust dissolves in groundwater where seismic Rayleigh and P waves cause dilational strain, which can reduce pore fluid pressure to or below the bubble pressure, triggering CO2 gas bubble growth in the saturated zone, indicated by a spontaneous buildup of pore fluid pressure. Excess pore fluid pressure was measured in response to the application of 0.1-1.0 MPa, 0.01-0.30 Hz confining stress oscillations to a Berea sandstone core flooded with initially subsaturated aqueous CO2, under conditions representative of a confined aquifer. Confining stress oscillations equivalent to the dynamic stress of the 28 June 1992 Mw 7.3 Landers, California, earthquake Rayleigh wave as it traveled through the Long Valley caldera, and Parkfield, California, increased the pore fluid pressure in the Berea core by an average of 36 ± 15 cm and 23 ± 15 cm of equivalent freshwater head, respectively, in agreement with 41.8 cm and 34 cm rises recorded in wells at those locations.

  9. Contribution of seismic processing to put up the scaffolding for the 3-dimensional study of deep sedimentary basins: the fundaments of trans-national 3D modelling in the project GeoMol

    Capar, Laure

    2013-04-01

    Within the framework of the transnational project GeoMol geophysical and geological information on the entire Molasse Basin and on the Po Basin are gathered to build consistent cross-border 3D geological models based on borehole evidence and seismic data. Benefiting from important progress in seismic processing, these new models will provide some answers to various questions regarding the usage of subsurface resources, as there are geothermal energy, CO2 and gas storage, oil and gas production, and support decisions-making to national and local administrations as well as to industries. More than 28 000 km of 2D seismic lines are compiled reprocessed and harmonized. This work faces various problems like the vertical drop of more than 700 meters between West and East of the Molasse Basin and to al lesser extent in the Po Plain, the heterogeneities of the substratum, the large disparities between the period and parameters of seismic acquisition, and depending of their availability, the use of two types of seismic data, raw and processed seismic data. The main challenge is to harmonize all lines at the same reference level, amplitude and step of signal processing from France to Austria, spanning more than 1000 km, to avoid misfits at crossing points between seismic lines and artifacts at the country borders, facilitating the interpretation of the various geological layers in the Molasse Basin and Po Basin. A generalized stratigraphic column for the two basins is set up, representing all geological layers relevant to subsurface usage. This stratigraphy constitutes the harmonized framework for seismic reprocessing. In general, processed seismic data is available on paper at stack stage and the mandatory information to take these seismic lines to the final stage of processing, the migration step, are datum plane and replacement velocity. However several datum planes and replacement velocities were used during previous processing projects. Our processing sequence is to

  10. The Application of Borehole Seismic Techniques in Mine Development at the Millennium Uranium Deposit, Northern Saskatchewan, Canada

    The Millennium uranium deposit is located within the Athabasca Basin of northern Saskatchewan, Canada. The deposit is situated in metasedimentary rocks, is controlled by multiple sub-vertical faults, and crossfaults and is overlain by over 500 m of intensely altered, porous Manitou Falls group sandstones. The rock quality directly surrounding the deposit is greatly reduced because of alteration and post-Athabasca sandstone structures, which provide conduits for the migration of basinal and meteoric fluids. This leads to significant risk for mine development and shaft sinking, because of the increased potential for water inflow into mine workings. To mitigate the risk involved with mining in such complex geology several projects were proposed as part of a pre-feasibility study. Of these, seismic methods were identified as the best tool to potentially identify alteration and structurally compromised zones. Subsequently, a comprehensive surface and borehole seismic program was completed in an attempt to delineate these engineering hazards and to provide assurance of success of the shaft sinking and mine development. This was the first time a seismic program of this scale was undertaken for geotechnical studies during mine development in the Athabasca Basin. (author)

  11. OGS improvements in 2012 in running the North-eastern Italy Seismic Network: the Ferrara VBB borehole seismic station

    Pesaresi, D.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma1, Roma, Italia; Romanelli, M.; OGS; Barnaba, C.; OGS, Trieste; Bragato, P. L.; OGS; Durì, G.; OGS

    2014-01-01

    The Centro di Ricerche Sismologiche (CRS, Seismological Research Centre) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the North-eastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler short period seismic...

  12. Construction of System for Seismic Observation in Deep Borehole (SODB) - Development of Multi-depth, High-temperature/pressure resistance seismometer

    The development of a high quality system for seismic observation in deep boreholes, the installation process at the NIIT site, and the data sharing plan for this observation were explained. The key points of the development were high temperature resistance (150 degrees Celsius), high pressure resistance (30 MPa), and a high dynamic/wide frequency range seismometer which allows for observation of micro-tremor to strong motions as well as a cascade-connection-type borehole seismometer, which allows multiple probes to be set at several depths in a single borehole. The developed system consists of broadband (0.1-50 Hz) and high dynamic range (up to 1000 gal) seismometer with electronic parts on the ground and only the pendulum part in the borehole (it became a servo-type seismometer). Durability and maintenance may be issues in the future. (author)

  13. Dynamical analysis of a PWR internals using super-elements in an integrated 3-D model model. Part 2: dynamical tests and seismic analysis

    The results of the test analysis (frequencies) for the isolated super-elements and for the developed 3-D model of the internals core support structures of a PWR research reactor are presented. Once certified of the model effectiveness for this type of analysis the seismic spectral analysis was performed. From the results can be seen that the structures are rigid for this load, isolated or together with the other in the 3-D model, and there are no impacts among them during the earthquake (OBE). (author)

  14. The application of high-resolution 3D seismic data to model the distribution of mechanical and hydrogeological properties of a potential host rock for the deep storage of radioactive waste in France

    Mari, Jean-Luc

    2014-01-01

    In the context of a deep geological repository of high-level radioactive wastes, the French National Radioactive Waste Management Agency (Andra) has conducted an extensive characterization of the Callovo-Oxfordian argillaceous rock and surrounding formations in the Eastern Paris Basin. As part of this project, an accurate 3D seismic derived geological model is needed. The paper shows the procedure used for building the 3D seismic constrained geological model in depth by combining time-to-depth conversion of seismic horizons, consistent seismic velocity model and elastic impedance in time. It also shows how the 3D model is used for mechanical and hydrogeological studies. The 3D seismic field data example illustrates the potential of the proposed depth conversion procedure for estimating density and velocity distributions, which are consistent with the depth conversion of seismic horizons using the Bayesian Kriging method. The geological model shows good agreement with well log data obtained from a reference we...

  15. The multi-parameter borehole system and high resolution seismic studies in the western part of the main Marmara Fault in the frame of MARSITE Project.

    Ozel, Oguz; Guralp, Cansun; Tunc, Suleyman; Yalcinkaya, Esref

    2016-04-01

    The main objective of this study is to install a multi-parameter borehole system and surface array as close to the main Marmara Fault (MMF) in the western Marmara Sea as possible, and measure continuously the evolution of the state of the fault zone surrounding the MMF and to detect any anomaly or change, which may occur before earthquakes by making use of the data from the arrays already running in the eastern part of the Marmara Sea. The multi-parameter borehole system is composed of very wide dynamic range and stable borehole (VBB) broad band seismic sensor, and incorporate strain meter, tilt meter, and temperature and local hydrostatic pressure measuring devices. The borehole seismic station uses the latest update technologies and design ideas to record "Earth tides" signals to the smallest magnitude -3 events. Additionally, a surface microearthquake observation array, consisting of 8-10 seismometers around the borehole is established to obtain continuous high resolution locations of micro-seismicity and to better understand the existing seismically active structures and their roles in local tectonic settings.Bringing face to face the seismograms of microearthquakes recorded by borehole and surface instruments portrays quite different contents. The shorter recording duration and nearly flat frequency spectrum up to the Nyquist frequencies of borehole records are faced with longer recording duration and rapid decay of spectral amplitudes at higher frequencies of a surface seismogram. The main causative of the observed differences are near surface geology effects that mask most of the source related information the seismograms include, and that give rise to scattering, generating longer duration seismograms. In view of these circumstances, studies on microearthquakes employing surface seismograms may bring on misleading results. Particularly, the works on earthquake physics and nucleation process of earthquakes requires elaborate analysis of tiny events. It is

  16. Joint environmental assessment for Chevron USA, Inc. and Santa Fe Energy Resources, Inc.: Midway Valley 3D seismic project, Kern County, California

    NONE

    1996-10-01

    The proposed Midway Valley 3D Geophysical Exploration Project covers approximately 31,444 aces of private lands, 6,880 acres of Department of Energy (DOE) Lands within Naval Petroleum Reserve 2 (NPR2) and 3,840 acres of lands administered by the Bureau of Land Management (BLM), in western Kern County, California. This environmental assessment (EA) presents an overview of the affected environment within the project area using results of a literature review of biological field surveys previously conducted within or adjacent to a proposed 3D seismic project. The purpose is to provide background information to identify potential and known locations of sensitive wildlife and special status plant species within the proposed seismic project area. Biological field surveys, following agency approved survey protocols, will be conducted during October through November 1996 to acquire current resources data to provide avoidance as the project is being implemented in the field.

  17. Joint environmental assessment for Chevron USA, Inc. and Santa Fe Energy Resources, Inc.: Midway Valley 3D seismic project, Kern County, California

    The proposed Midway Valley 3D Geophysical Exploration Project covers approximately 31,444 aces of private lands, 6,880 acres of Department of Energy (DOE) Lands within Naval Petroleum Reserve 2 (NPR2) and 3,840 acres of lands administered by the Bureau of Land Management (BLM), in western Kern County, California. This environmental assessment (EA) presents an overview of the affected environment within the project area using results of a literature review of biological field surveys previously conducted within or adjacent to a proposed 3D seismic project. The purpose is to provide background information to identify potential and known locations of sensitive wildlife and special status plant species within the proposed seismic project area. Biological field surveys, following agency approved survey protocols, will be conducted during October through November 1996 to acquire current resources data to provide avoidance as the project is being implemented in the field

  18. 3D seismic response of a limited valley via BEM using 2.5D analytical Green's functions for an infinite free-rigid layer

    António, Julieta; Tadeu, António

    2002-01-01

    This paper presents analytical solutions for computing the 3D displacements in a flat solid elastic stratum bounded by a rigid base, when it is subjected to spatially sinusoidal harmonic line loads. These functions are also used as Greens functions in a boundary element method code that simulates the seismic wave propagation in a confined or semi-confined 2D valley, avoiding the discretization of the free and rigid horizontal boundaries.

  19. Magma Migration Through the Continental Crust - 3-D Seismic and Thermo-mechanical Constraints on Sites of Crustal Contamination

    Wilson, M.; Wheeler, W.

    2002-12-01

    Current understanding of the processes and pathways by which magma travels from its mantle source, through the crust to the Earth's surface is limited by the lack of continuously exposed sections through "fossil" magmatic systems. We report results from a 50 x 30 km 3-D seismic reflection survey of part of the Voring rifted continental margin of Norway which provide the first detailed images of an entire crustal magmatic plumbing system, from a Moho-level magma chamber, through complexes of sills and dykes in the mid to upper crust, to lavas and vent fields extruded at the early Tertiary paleosurface. The Voring margin of Norway formed during a period of Late Cretaceous to early Tertiary (Eocene) continental break-up when Greenland rifted away from Eurasia, resulting in the opening the NE Atlantic Ocean. Rifting was accompanied by widespread magmatic activity, inferred to be related to the impingement of the Iceland mantle plume on the base of the continental lithosphere. Regionally, magma migration occurred in at least two pulses: 62-59 Ma (main initial phase) and 57-54 Ma (continental break-up phase). Wide-angle seismic experiments indicate the presence of a laccolith-like "high-velocity body" (HVB) in the lower crust beneath most of the outer Voring Basin with P-wave velocities (Vp 7.1-7.4 km/s) characteristic of basaltic igneous rocks, overlying typical mantle rocks with Vp of over 8 km/s. The HVB locally reaches 8 km thickness and at break-up (54 Ma) measured 300 km x 500 km - corresponding to a volume of 450,000 cubic km of basaltic magma. It is interpreted as a magmatic underplate formed over a period of several million years as rising basaltic magmas ponded at the Moho at their level of neutral buoyancy. A laterally extensive sill complex (1000 m thick) occurs at the interface between thinned crystalline basement and the overlying Mesozoic sedimentary sequence. This is interpreted as one of the main intra-crustal magma storage reservoirs and is the most

  20. Record of Subducting Topography revealed in 3D Seismic Imaging of Pleistocene unconformities, offshore Southern Costa Rica

    Edwards, J. H.; Kluesner, J. W.; Silver, E. A.

    2015-12-01

    3D seismic reflection data (CRISP) collected across the southern Costa Rica forearc reveals broad, survey-wide erosional events in the upper ~1 km of slope sediments in the mid-slope to outer shelf. The upper 0-280 m of continuous, weakly deformed sediments, designated by IODP Expedition 344 as structural domain I, is bounded by a major erosional event, (CRISP-U1, dated near 1 Ma), suggesting wave-plain erosion from the present shelf break out to 25 km seaward, to a present-day water depth of 900-1300 m. The eastern toe of its surface is characterized by a large drainage system, likely including submarine channels that eroded to depths >1500 m below present-day water depth. CRISP-U1 is variably uplifted by a series of fault propagation folds and cut by an intersecting array of normal faults. Another, major erosional event, (CRISP-M1, approximately 2 Ma) extended from the outer shelf to the mid slope and removed 500-1000 m of material. Overlying CRISP-M1 is up to 1 km of sediments that are more deformed by fault propagation folds, back thrusts, and intersecting arrays of normal faults. Unconformities with smaller areal extent are variably found in these overlying sediments across the mid-slope to outer shelf, at present-day water depths >220 m. Below CRISP-M1, sediments are more densely deformed and also contain major unconformities that extend survey-wide. Both unconformities, CRISP-U1 and CRISP-M1, are encountered in well U1413 and are demarcated by major benthic foraminifera assemblage changes at 149 mbsf and ~504 mbsf (Harris et al., 2013, Proceeding of the IODP, Volume 344).CRISP-M1 is likely correlative to the major sediment facies and benthic foraminifera assemblage change found in U1379 at ~880 mbsf (Vannuchi et al., 2013). The unconformities and intersecting array of normal faults may demarcate the passing of topography on the downgoing Cocos plate, episodically lifting and then subsiding the Costa Rica margin, with amplitudes up to about 1 km.

  1. Earthquake relocation using a 3D a-priori geological velocity model from the western Alps to Corsica: Implication for seismic hazard

    Béthoux, Nicole; Theunissen, Thomas; Beslier, Marie-Odile; Font, Yvonne; Thouvenot, François; Dessa, Jean-Xavier; Simon, Soazig; Courrioux, Gabriel; Guillen, Antonio

    2016-02-01

    The region between the inner zones of the Alps and Corsica juxtaposes an overthickened crust to an oceanic domain, which makes difficult to ascertain the focal depth of seismic events using routine location codes and average 1D velocity models. The aim of this article is to show that, even with a rather lose monitoring network, accurate routine locations can be achieved by using realistic 3D modelling and advanced location techniques. Previous earthquake tomography studies cover the whole region with spatial resolutions of several tens of kilometres on land, but they fail to resolve the marine domain due to the absence of station coverage and sparse seismicity. To overcome these limitations, we first construct a 3D a-priori P and S velocity model integrating known geophysical and geological information. Significant progress has been achieved in the 3D numerical modelling of complex geological structures by the development of dedicated softwares (e.g. 3D GeoModeller), capable at once of elaborating a 3D structural model from geological and geophysical constraints and, possibly, of refining it by inversion processes (Calcagno et al., 2008). Then, we build an arrival-time catalogue of 1500 events recorded from 2000 to 2011. Hypocentres are then located in this model using a numerical code based on the maximum intersection method (Font et al., 2004), updated by Theunissen et al. (2012), as well as another 3D location technique, the NonLinLoc software (Lomax and Curtis, 2001). The reduction of arrival-time residuals and uncertainties (dh, dz) with respect to classical 1D locations demonstrates the improved accuracy allowed by our approach and confirms the coherence of the 3D geological model built and used in this study. Our results are also compared with previous works that benefitted from the installation of dense temporary networks surrounding the studied epicentre area. The resulting 3D location catalogue allows us to improve the regional seismic hazard assessment

  2. Next-generation seismic experiments - II: wide-angle, multi-azimuth, 3-D, full-waveform inversion of sparse field data

    Morgan, Joanna; Warner, Michael; Arnoux, Gillean; Hooft, Emilie; Toomey, Douglas; VanderBeek, Brandon; Wilcock, William

    2016-02-01

    3-D full-waveform inversion (FWI) is an advanced seismic imaging technique that has been widely adopted by the oil and gas industry to obtain high-fidelity models of P-wave velocity that lead to improvements in migrated images of the reservoir. Most industrial applications of 3-D FWI model the acoustic wavefield, often account for the kinematic effect of anisotropy, and focus on matching the low-frequency component of the early arriving refractions that are most sensitive to P-wave velocity structure. Here, we have adopted the same approach in an application of 3-D acoustic, anisotropic FWI to an ocean-bottom-seismometer (OBS) field data set acquired across the Endeavour oceanic spreading centre in the northeastern Pacific. Starting models for P-wave velocity and anisotropy were obtained from traveltime tomography; during FWI, velocity is updated whereas anisotropy is kept fixed. We demonstrate that, for the Endeavour field data set, 3-D FWI is able to recover fine-scale velocity structure with a resolution that is 2-4 times better than conventional traveltime tomography. Quality assurance procedures have been employed to monitor each step of the workflow; these are time consuming but critical to the development of a successful inversion strategy. Finally, a suite of checkerboard tests has been performed which shows that the full potential resolution of FWI can be obtained if we acquire a 3-D survey with a slightly denser shot and receiver spacing than is usual for an academic experiment. We anticipate that this exciting development will encourage future seismic investigations of earth science targets that would benefit from the superior resolution offered by 3-D FWI.

  3. OGS improvements in 2012 in running the North-eastern Italy Seismic Network: the Ferrara VBB borehole seismic station

    D. Pesaresi; Romanelli, M.; BARNABA, C; Bragato, P. L.; Durì, G.

    2014-01-01

    The Centro di Ricerche Sismologiche (CRS, Seismological Research Centre) of the Istituto Nazionale di Oceanografia e di Geofisica Sperimentale (OGS, Italian National Institute for Oceanography and Experimental Geophysics) in Udine (Italy) after the strong earthquake of magnitude M=6.4 occurred in 1976 in the Italian Friuli-Venezia Giulia region, started to operate the North-eastern Italy Seismic Network: it currently consists of 17 very sensitive broad band and 18 simpler sh...

  4. Integration of borehole geophysical properties into surface multichannel seismic data sets: First results from the SCOPSCO ICDP project

    Lindhorst, Katja; Krastel, Sebastian; Baumgarten, Henrike; Wonik, Thomas; Francke, Alexander; Wagner, Bernd

    2015-04-01

    Lake Ohrid (Macedonia/Albania), located on the Balkan Peninsula within the Dinaride-Hellenide-Albanide mountain belt is probably the oldest, continuously existing lake in Europe (2-5 Ma). Multidisciplinary studies at Lake Ohrid prove that it is an important archive to study the sedimentary and tectonic evolution of a graben system over a long time period. Within the frame of the International Continental Drilling Program (ICDP) a successful deep drilling campaign was carried out in spring 2013 with more than 2000 m of sediment cores at four sites. Downhole logging was realized at each site after coring, enabling us to integrate geophysical and sedimentological data into seismic cross sections in order to get a profound knowledge of climatic and environmental changes in the catchment area. The longest record (~569 m, site DEEP), recovered in the central part of lake Ohrid likely covers the entire lacustrine succession within Lake Ohrid Basin including several Interglacial and Glacial cycles. Sedimentological analyses are still ongoing; however, the upper 260 m of the DEEP reflecting the time period between Mid-Pleistocene Transition to present. An integration of borehole geophysical data into surface seismic lines shows that sediments, within the central part of Lake Ohrid, were deposited in a deep water environment over the last 600 ka. For the uppermost sediment cover, about 50 m of penetration, a very high resolution sediment echosounder data set allows us to identify major tephra layers and track them through the entire deep basin. Furthermore, a vertical seismic profile was carried out at site DEEP resulting in a conversion from two-way-travel-time into sediment depth. One major outcome is a corridor stack of the upgoing wave that clearly shows several reflectors linked to changes of sediment properties of cores and hence environmental and climate changes in the surrounding area of Lake Ohrid Basin. Several changes from Glacial to Interglacial, and vice versa

  5. Computing 3-D wavefields in mantle circulations models to test hypotheses on the origin of lower mantle heterogeneity under Africa directly against seismic observations

    Schuberth, Bernhard; Zaroli, Christophe; Nolet, Guust

    2015-04-01

    Of particular interest for the tectonic evolution of the Atlantic region is the influence of lower mantle structure under Africa on flow in the upper mantle beneath the ocean basin. Along with its Pacific counterpart, the large African anomaly in the lowermost mantle with strongly reduced seismic velocities has received considerable attention in seismological and geodynamic studies. Several seismological observations are typically taken as an indication that these two anomalies are being caused by large-scale compositional variations and that they are piles of material with higher density than normal mantle rock. This would imply negative buoyancy in the lowermost mantle under Africa, which has important implications for the flow at shallower depth and inferences on the processes that led to the formation of the Atlantic Ocean basin. However, a large number of recent studies argue for a strong thermal gradient across the core-mantle boundary that might provide an alternative explanation for the lower mantle anomaly through the resulting large lateral temperature variations. Recently, we developed a new joint forward modeling approach to test such geodynamic hypotheses directly against the seismic observations: Seismic heterogeneity is predicted by converting the temperature field of a high-resolution 3-D mantle circulation model into seismic velocities using thermodynamic models of mantle mineralogy. 3-D global wave propagation in the synthetic elastic structures is then simulated using a spectral element method. Being based on forward modelling only, this approach allows us to generate synthetic wavefields and seismograms independently of seismic observations. The statistics of observed long-period body wave traveltime variations show a markedly different behaviour for P- and S-waves: the standard deviation of P-wave delay times stays almost constant with ray turning depth, while that of the S-wave delay times increases strongly throughout the mantle. In an

  6. Ryukyu Subduction Zone: 3D Geodynamic Simulations of the Effects of Slab Shape and Depth on Lattice-Preferred Orientation (LPO) and Seismic Anisotropy

    Tarlow, S.; Tan, E.; Billen, M. I.

    2015-12-01

    At the Ryukyu subduction zone, seismic anisotropy observations suggest that there may be strong trench-parallel flow within the mantle wedge driven by complex 3D slab geometry. However, previous simulations have either failed to account for 3D flow or used the infinite strain axis (ISA) approximation for LPO, which is known to be inaccurate in complex flow fields. Additionally, both the slab depth and shape of the Ryukyu slab are contentious. Development of strong trench-parallel flow requires low viscosity to decouple the mantle wedge from entrainment by the sinking slab. Therefore, understanding the relationship between seismic anisotropy and the accompanying flow field will better constrain the material and dynamic properties of the mantle near subduction zones. In this study, we integrate a kinematic model for calculation of LPO (D-Rex) into a buoyancy-driven, instantaneous 3D flow simulation (ASPECT), using composite non-Newtonian rheology to investigate the dependence of LPO on slab geometry and depth at the Ryukyu Trench. To incorporate the 3D flow effects, the trench and slab extends from the southern tip of Japan to the western edge of Taiwan and the model region is approximately 1/4 of a spherical shell extending from the surface to the core-mantle boundary. In the southern-most region we vary the slab depth and shape to test for the effects of the uncertainties in the observations. We also investigate the effect of adding locally hydrated regions above the slab that affect both the mantle rheology and development of LPO through the consequent changes in mantle flow and dominate (weakest) slip system. We characterize how changes in the simulation conditions affect the LPO within the mantle wedge, subducting slab and sub-slab mantle and relate these to surface observations of seismic anisotropy.

  7. Late-stage stretching and subsidence rates in the Danakil Depression, evidenced from borehole records and seismic reflection data

    Booth, Adam; Bastow, Ian; Magee, Craig; Keir, Derek; Corti, Giacomo; Jackson, Chris; Wilkinson, Jason

    2016-04-01

    The Ethiopian and Afar Rift systems provide a globally unique opportunity to study the incipient transition from continental rifting to sea-floor spreading. A consensus has emerged that a considerable proportion of plate extension in Ethiopia is accommodated by dyke intrusion, with smaller contributions from crustal thinning. However, observations of thinned crust and a pulse in Quaternary-Recent basaltic volcanism within Ethiopia's Danakil Depression have been cited (Bastow and Keir, 2011) as evidence that localised plate stretching may mark the final stages of continent-ocean transition. We explore this hypothesis using an archive of five 2-D seismic reflection profiles, each between 7-10 km in length, and ˜120 borehole records distributed over an area of 225 km2. From depth and age relationships of key marker horizons, we also suggest local subsidence and extension rates. The borehole archive reveals extensive evaporite sequences deposited in and around an asymmetric basin, bounded to the west by a network of east-dipping normal faults. West of the basin, the maximum observed thickness of evaporites is 150 m, beneath which are deposits of clastic sediment, but a sequence of evaporites at least 900 m thick is observed at the basin centre. The sedimentary architecture of these sequences suggests deposition in a shallow salt-pan environment, with seasonal - potentially diurnal - freshening of the brine supply (Warren, 2012). Isotopic analysis of reef carbonates in the basin flank dates the last marine incursion into the Danakil Depression at 24-230ka (Lalou et al., 1970; Bonatti et al., 1971; Bannert et al., 1971), therefore the evaporite sequence must be younger than this. A key marker horizon within the evaporites is the potash-bearing Houston Formation, also distinct in borehole records given its high porosity (25-40%) and radioactivity (50-250 API units). The elevation of the Houston Formation is ˜500 m deeper in the centre of the basin than on the flank

  8. Joint-inversion of Seismic and Gravity Survey Data in Sedimentary Basins for 3-D Underground Structures in Strong Motion Simulation

    Koketsu, K.; Afnimar, A.

    2001-12-01

    Modeling of underground structures is one of important tasks for strong motion predition. Seismic surveys such as refraction and reflection explorations can give precise estimates of seismic velocities, but they are too expensive to cover the whole area of a sedimentary basin with a fine spacing of survey points. On the other hand, gravity surveys can be carried out densely and homogeneously with reasonable cost, but they cannot measure seismic velocities directly. In order to compromise this inconsistency, we combine data from the seismic and gravity surveys, and jointly invert them assuming a relation between densities and seismic velocities. An interface separating sediments and basement rocks is parameterized by the Lagrange interpolation with knot points distributed for representing a steep part related to a fault zone. The linear and absolute constraints are imposed to avoid oscillatory artifacts in the solution and to minimize the non-uniqueness of the solution. The joint inversion also overcome the ray coverage problem of a refraction survey in a complex underground structure. The validity of the formulation is verified using synthetic data for a valley-like basin with pseudo-random noises. The proposed method is successfully applied to the actual data obtained in and around the Osaka basin, Japan. The result shows a good agreement with the geological setting in this region. The instability due to the lack of data beneath the Osaka bay is improved by the introduction of the absolute constraints. We then apply the method to the Kanto basin around Tokyo assuming two layers in the sediments. This layering increases the number of variables introducing some instabilities into the inversion, and so measurements at boreholes and reflection survey lines are used as fixed points in the model.

  9. Aftershock Sequences Modeled with 3-D Stress Heterogeneity and Rate-State Seismicity Equations: Implications for Crustal Stress Estimation

    Smith, Deborah Elaine; Dieterich, James H.

    2010-01-01

    In this paper, we present a model for studying aftershock sequences that integrates Coulomb static stress change analysis, seismicity equations based on rate-state friction nucleation of earthquakes, slip of geometrically complex faults, and fractal-like, spatially heterogeneous models of crustal stress. In addition to modeling instantaneous aftershock seismicity rate patterns with initial clustering on the Coulomb stress increase areas and an approximately 1/t diffusion back to the pre-mains...

  10. System and method for generating 3D images of non-linear properties of rock formation using surface seismic or surface to borehole seismic or both

    Vu, Cung Khac; Nihei, Kurt Toshimi; Johnson, Paul A.; Guyer, Robert A.; Ten Cate, James A.; Le Bas, Pierre-Yves; Larmat, Carene S.

    2016-06-07

    A system and method of characterizing properties of a medium from a non-linear interaction are include generating, by first and second acoustic sources disposed on a surface of the medium on a first line, first and second acoustic waves. The first and second acoustic sources are controllable such that trajectories of the first and second acoustic waves intersect in a mixing zone within the medium. The method further includes receiving, by a receiver positioned in a plane containing the first and second acoustic sources, a third acoustic wave generated by a non-linear mixing process from the first and second acoustic waves in the mixing zone; and creating a first two-dimensional image of non-linear properties or a first ratio of compressional velocity and shear velocity, or both, of the medium in a first plane generally perpendicular to the surface and containing the first line, based on the received third acoustic wave.

  11. Development of a New Parallel Code for 3-D Joint Refraction and Reflection Travel-Time Tomography of Wide-Angle Seismic Data. Synthetic and Real Data Applications to the Study of Subduction Zones

    Meléndez, Adrià

    2014-01-01

    [eng] This dissertation is devoted to seismic tomography. I have implemented a new modelling tool for 3-D joint refraction and reflection travel-time tomography of wide-angle seismic data (TOMO3D). The reason behind this central objective is the evidence that the information based on 2-D seismic data does not allow to capture the structural complexity of many 3-D targets, and in particular that of the seismogenic zone in subduction margins. The scientific rationale for this statement, which j...

  12. A high-resolution 3D seismic velocity model of the 2010 Mw 8.8 Maule, Chile earthquake rupture zone using land & OBS networks

    Hicks, S. P.; Rietbrock, A.; Ryder, I. M.; Miller, M.; Lee, C.

    2013-12-01

    Knowledge of seismic properties along a subduction megathrust can shed light on the composition and structure of rocks along the fault. By comparing seismic velocity structure with models of interseismic locking, co-seismic slip and afterslip, we can begin to understand how physical properties may affect fault dynamics throughout the subduction seismic cycle. The Maule earthquake, which hit the coast of central Chile in 2010, is the 6th largest earthquake ever recorded, rupturing a 500 x 80 km area of the Chilean megathrust. Published models demonstrate a complex bilateral rupture, with most co-seismic slip occurring to the north of the mainshock epicentre, although significant slip likely stopped short of the trench and the continental Moho. Here, we show a new high-resolution 3D velocity model (vp and vp/vs ratio) of the central Chilean margin Our velocity model is based on manually picked P- and S-wave arrival times from 670 aftershocks recorded by the International Maule Aftershock Deployment (IMAD) network. Seismic properties of the marine forearc are poorly understood in subduction zones, but by incorporating picks from two ocean-bottom seismometer (OBS) networks, we can resolve the velocity structure of the megathrust as far as the trench. In total, the catalogue used for the tomographic inversion yields a total of ~50,000 high quality P- and S-wave picks. We analyse the quality of our model by analysis of the resolution matrix and by testing characteristic models. The 3D velocity model shows the main structures associated within a subduction forearc: the marine forearc basin (vp 7.5 km/s), and subducting oceanic crust (vp ~ 7.7 km/s). The plate interface is well defined by relocated aftershock seismicity. P-wave velocities along the megathrust range from 6.5 km/s beneath the marine forearc to 7.7 km/s at the intersection of the megathrust with the continental Moho. We infer several high vp anomalies within the South American forearc that are also expressed

  13. Application of the 3D Seismic in decollement structure interpretation%三维地震勘探在滑动构造解释中的应用

    刘卫; 高召奎

    2016-01-01

    滑动构造影响了煤层赋存特征,改变了煤层厚度和埋深,对煤矿开采不利。以河南某区滑动构造解释为实例,介绍了三维地震技术在精细刻画滑动构造中的解释应用,讨论了滑动面在时间剖面上和三维数据体上的识别特征。结果表明,三维地震勘探是一种有效的滑动构造探测手段。%Decollement structure has big effect on the occurrence, thickness and depth of coal seam, particalarly on coal mining. This paper illustrates the application of 3D-seismic exploration technology in nicely depicting decollement structure by taking the decollement structure interpretation of one district in Henan Province, discusses the recognition feature of decollement surface on the time section and 3D data cubes, explains that 3D-seismic is an effective detection means for decollement structure.

  14. Seismic attribute detection of faults and fluid pathways within an active strike-slip shear zone: New insights from high-resolution 3D P-Cable™ seismic data along the Hosgri Fault, offshore California

    Kluesner, Jared; Brothers, Daniel

    2016-01-01

    Poststack data conditioning and neural-network seismic attribute workflows are used to detect and visualize faulting and fluid migration pathways within a 13.7 km2 13.7 km2 3D P-Cable™ seismic volume located along the Hosgri Fault Zone offshore central California. The high-resolution 3D volume used in this study was collected in 2012 as part of Pacific Gas and Electric’s Central California Seismic Imaging Project. Three-dimensional seismic reflection data were acquired using a triple-plate boomer source (1.75 kJ) and a short-offset, 14-streamer, P-Cable system. The high-resolution seismic data were processed into a prestack time-migrated 3D volume and publically released in 2014. Postprocessing, we employed dip-steering (dip and azimuth) and structural filtering to enhance laterally continuous events and remove random noise and acquisition artifacts. In addition, the structural filtering was used to enhance laterally continuous edges, such as faults. Following data conditioning, neural-network based meta-attribute workflows were used to detect and visualize faults and probable fluid-migration pathways within the 3D seismic volume. The workflow used in this study clearly illustrates the utility of advanced attribute analysis applied to high-resolution 3D P-Cable data. For example, results from the fault attribute workflow reveal a network of splayed and convergent fault strands within an approximately 1.3 km wide shear zone that is characterized by distinctive sections of transpressional and transtensional dominance. Neural-network chimney attribute calculations indicate that fluids are concentrated along discrete faults in the transtensional zones, but appear to be more broadly distributed amongst fault bounded anticlines and structurally controlled traps in the transpressional zones. These results provide high-resolution, 3D constraints on the relationships between strike-slip fault mechanics, substrate deformation, and fluid migration along an active

  15. Relocation of the Waldkirch seismic event, December 5, 2004, with regional 1D- and 3D-velocity models in the presence of upper mantle anisotropy

    Muench, Thomas; Koch, Manfred; Schlittenhard, Jörg

    2010-05-01

    On December 5, 2004 a strong earthquake occurred near the city of Waldkirch, about 30 km's north of Freiburg, with a local magnitude of ML = 5.4. This seismic event was one of the strongest observed since the ML = 5.7 'Schwäbische Alb' event of September 3, 1978, 30 years before. In the aftermath of the event several institutions (Bens, BGR, LGBR, LED, SED and NEIC) have attempted to relocate this earthquake that came up with a hypocentral depth range of 9 - 12 km which. In fact, as the exact hypocentral location of the Waldkirch - and other events in the area - namely, the seismic depths, are of utmost importance for the further understanding of the seismotectonics as well as of the seismic hazard in the upper Rhinegraben area, one cannot over stress the necessity for a hypocenter relocation as best as possible. This requires a careful analysis of all factors that may impede an unbiased relocation of such an event. In the present talk we put forward the question whether the Waldkirch seismic event can be relocated with sufficient accuracy by a regional network when, additionally, improved regional 1D- and 3D seismic velocity models for the crust and upper mantle that take into consideration Pn-anisotropy of the upper mantle beneath Germany are employed in the hypocentral determination process. The seismological work starts with a comprehensive analysis of the dataset available for the relocation of the event. By means of traveltime curves a reevaluation of the observed phases is done and it is shown that some of the big observed traveltime residuals are most likely the consequence of wrongly associated phases as well as of the neglect of the anisotropic Pn traveltime correction for the region. Then hypcocenter relocations are done for 1D vertically inhomogeneous and 3D laterally inhomogeneous seismic velocity models, without and with the anisotropic Pn-traveltime correction included. The effects of the - often not well-known - Moho depth and of the VP

  16. High-Resolution 3D-Seismic Investigations Indicate Focused Fluid Flow Systems in Hydrated Sediments at the Vestnesa Ridge off the W-Svalbard Margin.

    Petersen, C.; Buenz, S.; Hustoft, S.; Mienert, J.

    2007-12-01

    High-resolution seismic data were acquired using the 3D seismic P-Cable system of the University of Tromsoe to investigate how the fluid flow penetrates gas hydrate systems of the Vestnesa Ridge. The ridge represents a current-controlled sediment drift on the continental margin offshore western Svalbard. The survey area is located at the northwestern part of the Vestnesa Ridge and centered at the ridge crest that resembles an anticline in a water depth of 1250-1320 m. The seafloor morphology at the crest is characterized by an abundance of pockmarks with a diameter between 50-500 m indicating recent fluid flow activity. Since the area is within the gas hydrate stability zone (GHSZ), it is an ideal site to understand where and how fluids escape through a hydrated sediment drift. 35 reflection seismic profiles with a spacing of about 40-60 m were shot resulting in a seismic cube covering an area of approximately 22 km2. In addition, regional single channel streamer (SCS) seismic lines were acquired across the ridge perpendicular to the crest to connect the 3D area with the regional structural setting. The seismic data provide images of the subsurface to about 500 ms TWT (two-way time) below the seafloor (bsf), where gas accumulations cause acoustic attenuations that hinder deeper acoustic signal penetration. The well-stratified sediments exhibit a bottom simulating reflector (BSR) at about 200 ms TWT bsf at the base of the GHSZ. The BSR is difficult to identify due to the stratification, but it is accompanied by the onset of an ubiquitous band of strong reflectivity indicating free gas accumulation zones beneath the GHSZ. Fluid flow activity is evident from a link between gas accumulations (bright spots), gas wipeouts and disturbed reflectivity in the seismic data. These features are observed not only beneath the pockmark structures, but also in the sediment without seafloor expressions of fluid venting. The fluid source might be related to deep tectonic processes at

  17. Variations in geoacoustic emissions in a deep borehole and its correlation with seismicity

    A. Storcheus

    2008-06-01

    Full Text Available Continuous geoacoustic emission (GAE measurements were acquired using a three-component geophone placed in a borehole at a depth of near 1000 m at Petropavlovsk-Kamchatsky starting in August 2000. Using geophones consisting of magneto-elastic crystal ferromagnetic sensors, and installed at such a depth allows measurement of natural geoacoustic background with signal amplitude less than 1×10-4 m/s3 in frequency band from 3 to 1500 Hz. According to the data from a 4-year survey period the characteristics of diurnal geoacoustic variations change before every earthquake with MLH? 5.0 that occurs at a distance of less than 300 km from the observation point or before each earthquake with MLH?5.5 occurring at distance R?550 km from the observation point. The changes in GAE regime correlate with the strongest earthquakes that occurred during survey period. Measurements of the natural electromagnetic field of the Earth were carried out simultaneously with the help of an underground electric antenna. The behavior of GAE in aseismic periods appears to be related to the effect of diurnal variations of the natural electromagnetic field.

  18. 3D seismic interpretation of subsurface eruptive centers in a Permian large igneous province, Tazhong Uplift, central Tarim Basin, NW China

    Yang, Jiangfeng; Zhu, Wenbin; Guan, Da; Zhu, Beibei; Yuan, Liansheng; Xiang, Xuemei; Su, Jinbao; He, Jingwen; Wu, Xinhui

    2015-12-01

    A 1445-km2 high-resolution 3D seismic reflection dataset is used to analyze the Permian large igneous province in the subsurface of the Tazhong area in the central Tarim Basin in northwestern China. Constrained by the synthetic seismograms of four wells, the top and base of the igneous rocks were identified in the seismic data. Seven large volcanic craters, each >10 km2 in area, have been discovered via the application of coherency and amplitude attributes. The thickness and volume of the igneous rocks were obtained by time-depth transformation. In the study area, all of the igneous rocks, with thicknesses from 120 to 1133 m, were formed by eruptions in the Early Permian. These events produced huge erupted volumes (178 km3) and multiple closely spaced volcanic edifices (eruptive center of the Permian igneous rocks in the Tarim Basin.

  19. Analysis of ancient-river systems by 3D seismic time-slice technique: A case study in northeast Malay Basin, offshore Terengganu, Malaysia

    Fluvial sandstones constitute one of the major clastic petroleum reservoir types in many sedimentary basins around the world. This study is based on the analysis of high-resolution, shallow (seabed to 500 m depth) 3D seismic data which generated three-dimensional (3D) time slices that provide exceptional imaging of the geometry, dimension and temporal and spatial distribution of fluvial channels. The study area is in the northeast of Malay Basin about 280 km to the east of Terengganu offshore. The Malay Basin comprises a thick (> 8 km), rift to post-rift Oligo-Miocene to Pliocene basin-fill. The youngest (Miocene to Pliocene), post-rift succession is dominated by a thick (1–5 km), cyclic succession of coastal plain and coastal deposits, which accumulated in a humid-tropical climatic setting. This study focuses on the Pleistocene to Recent (500 m thick) succession, which comprises a range of seismic facies analysis of the two-dimensional (2D) seismic sections, mainly reflecting changes in fluvial channel style and river architecture. The succession has been divided into four seismic units (Unit S1-S4), bounded by basin-wide strata surfaces. Two types of boundaries have been identified: 1) a boundary that is defined by a regionally-extensive erosion surface at the base of a prominent incised valley (S3 and S4); 2) a sequence boundary that is defined by more weakly-incised, straight and low-sinuosity channels which is interpreted as low-stand alluvial bypass channel systems (S1 and S2). Each unit displays a predictable vertical change of the channel pattern and scale, with wide low-sinuosity channels at the base passing gradationally upwards into narrow high-sinuosity channels at the top. The wide variation in channel style and size is interpreted to be controlled mainly by the sea-level fluctuations on the widely flat Sunda land Platform

  20. 3D modelling of the active normal fault network in the Apulian Ridge (Eastern Mediterranean Sea): Integration of seismic and bathymetric data with implicit surface methods

    Bistacchi, Andrea; Pellegrini, Caludio; Savini, Alessandra; Marchese, Fabio

    2016-04-01

    The Apulian ridge (North-eastern Ionian Sea, Mediterranean), interposed between the facing Apennines and Hellenides subduction zones (to the west and east respectively), is characterized by thick cretaceous carbonatic sequences and discontinuous tertiary deposits crosscut by a penetrative network of NNW-SSE normal faults. These are exposed onshore in Puglia, and are well represented offshore in a dataset composed of 2D seismics and wells collected by oil companies from the '60s to the '80s, more recent seismics collected during research projects in the '90s, recent very high resolution seismics (VHRS - Sparker and Chirp-sonar data), multibeam echosounder bathymetry, and sedimentological and geo-chronological analyses of sediment samples collected on the seabed. Faults are evident in 2D seismics at all scales, and their along-strike geometry and continuity can be characterized with multibeam bathymetric data, which show continuous fault scarps on the seabed (only partly reworked by currents and covered by landslides). Fault scarps also reveal the finite displacement accumulated in the Holocene-Pleistocene. We reconstructed a 3D model of the fault network and suitable geological boundaries (mainly unconformities due to the discontinuous distribution of quaternary and tertiary sediments) with implicit surface methods implemented in SKUA/GOCAD. This approach can be considered very effective and allowed reconstructing in details complex structures, like the frequent relay zones that are particularly well imaged by seafloor geomorphology. Mutual cross-cutting relationships have been recognized between fault scarps and submarine mass-wasting deposits (Holocene-Pleistocene), indicating that, at least in places, these features are coeval, hence the fault network should be considered active. At the regional scale, the 3D model allowed measuring the horizontal WSW-ENE stretching, which can be associated to the bending moment applied to the Apulian Plate by the combined effect

  1. 3-D seismic acquisition geometry design and analysis: Investigation of the requirements to include illumination from all multiples

    Kumar, A.

    2015-01-01

    A seismic survey should be designed such that imaging of the acquired data leads to a sufficiently accurate subsurface image. For that purpose, methods for acquisition geometry analysis and design are available. These methods are used to judge whether an acquisition geometry is suited for the specif

  2. The application of high-resolution 3D seismic data to model the distribution of mechanical and hydrogeological properties of a potential host rock for the deep storage of radioactive waste in France

    Mari, Jean-Luc; Yven, Béatrice

    2014-01-01

    In the context of a deep geological repository of high-level radioactive wastes, the French National Radioactive Waste Management Agency (Andra) has conducted an extensive characterization of the Callovo-Oxfordian argillaceous rock and surrounding formations in the Eastern Paris Basin. As part of this project, an accurate 3D seismic derived geological model is needed. The paper shows the procedure used for building the 3D seismic constrained geological model in depth by combining time-to-dept...

  3. a Borehole Seismic System for Active and Passive Seimsic Studies to 3 KM at Ptrc's Aquistore Project

    Schmitt, D. R.; Nixon, C.; Kofman, R.; White, D. J.; Worth, K.

    2015-12-01

    We have constructed a downhole seismic recording system for application to depths of nearly 3 km and temperatures up to 135 °C at Aquistore, an independent research and monitoring project in which liquid CO2 is being stored in a brine and sandstone water formation. The key component to this system is a set of commercially available slim-hole 3-C sondes carrying 15 Hz geophones deployable in open and cased boreholes with diameters as small as 57 mm. The system is currently hosted on a 4-conductor wireline with digital information streamed to the surface recording unit. We have further incorporated these sondes into a mobile passive monitoring unit that includes a number of redundancies such as a multiple Tbyte network accessible RAID hard-drive system (NAS) and a self-designed uninterruptible power supply. The system can be remotely controlled via the internet. The system is currently deployed covering a range of depths from 2850 m to 2910 m. Ambient temperatures at this depth are approximately 110 °C with onboard tool temperatures running at 115 °C. Data is continuously streamed to the NAS for archiving, approximately 11 GBytes of data is recorded per day at the sampling period of 0.5 ms. The lack of noise at this depth allows short data snippets to be flagged with a simple amplitude threshold criteria. The greatly reduced data volume of the snippets allows for ready access via the internet to the system for ongoing quality control. Spurious events, mostly small amplitude tube waves originating at or near the surface, are readily discounted. Active seismic measurements are carried out simultaneously but these require that an appropriately accurate independent GPS based time synchronization be used. Various experiences with event detection, orientation of sondes using both explosives and seismic vibrator, potential overheating of the surface electronics, and issues related to loss of shore power provide for a detailed case study. Aquistore, managed by the

  4. The comparison of DYNA3D to approximate solutions for a partially- full waste storage tank subjected to seismic loading

    Mathematical solutions to the problem consisting of a partially-full waste tank subjected to seismic loading, embedded in soil, is classically difficult in that one has to address: soil-structure interaction, fluid-structure interaction, non-linear behavior of material, dynamic effects. Separating the problem and applying numerous assumptions will yield approximate solutions. This paper explores methods for generating these solutions accurately

  5. a Multiple Data Set Joint Inversion Global 3d P-Velocity Model of the Earth's Crust and Mantle for Improved Seismic Event Location

    Ballard, S.; Begnaud, M. L.; Hipp, J. R.; Chael, E. P.; Encarnacao, A.; Maceira, M.; Yang, X.; Young, C. J.; Phillips, W.

    2013-12-01

    SALSA3D is a global 3D P wave velocity model of the Earth's crust and mantle developed specifically to provide seismic event locations that are more accurate and more precise than are locations from 1D and 2.5D models. In this paper, we present the most recent version of our model, for the first time jointly derived from multiple types of data: body wave travel times, surface wave group velocities, and gravity. The latter two are added to provide information in areas with poor body wave coverage, and are down-weighted in areas where body wave coverage is good. To constrain the inversions, we invoked empirical relations among the density, S velocity, and P velocity. We demonstrate the ability of the new SALSA3D model to reduce mislocations and generate statistically robust uncertainty estimates for a large set of realizations derived from a carefully chosen set of globally-distributed ground truth events. We obtain path-dependent travel time prediction uncertainties for our model by computing the full 3D model covariance matrix of our tomographic system and integrating the model slowness variance and covariance along paths of interest. This approach yields very low travel time prediction uncertainties for well-sampled paths through the Earth and higher uncertainties for paths that are poorly represented in the data set used to develop the model. While the calculation of path-dependent prediction uncertainties with this approach is computationally expensive, uncertainties can be pre-computed for a network of stations and stored in 3D lookup tables that can be quickly and efficiently interrogated using GeoTess software.

  6. 2D and 3D imaging of the metamorphic carbonates at Omalos plateau/polje, Crete, Greece by employing independent and joint inversion on resistivity and seismic data

    Pangratis Pangratis

    2012-07-01

    Full Text Available A geophysical survey carried out at Omalos plateau in Chania, Western Crete, Greece employed seismic as well as electrical tomography methods in order to image karstic structures and the metamorphic carbonates (Tripali unit and Plattenkalk group which are covered by post-Mesozoic deposits (terra rossa, clays, sands and gravels. The geoelectrical sections image the metamorphic carbonates which exhibit a highly irregular relief. At the central part of the plateau the thickness of post-Mesozoic deposits (terra rossa, clays, sands and gravels ranges from 40-130 m. A 3D resistivity image was generated by inverting resistivity data collected on a grid to the south west at the Omalos plateau. The 3D resistivity image delineated a karstic structure at a depth of 25 to 55 m. On the same grid the depth to the top of the karstified carbonates ranges from 25-70 m. This is also verified on the resistivity sections and seismic velocity sections along lines 5 and 7 of the above mentioned grid which are derived from the cross-gradients joint inversion.

  7. Investigations on alluvial deposits through borehole stratigraphy, radiocarbon dating and passive seismic technique (Carnic Alps, NE Italy)

    Viero, Alessia; Marchi, Lorenzo; Cavalli, Marco; Crema, Stefano; Fontana, Alessandro; Mozzi, Paolo; Venturini, Corrado

    2016-04-01

    their extent and the maximum depths. Two passive seismic campaigns were carried out near the borehole site and along the But valley at different elevations. The aim was to investigate the depth of the buried bedrock and therefore to indirectly characterize the thickness of alluvial deposits. We calibrated the fundamental frequency of each site by constraining average shear velocity of the alluvial sediments close to the borehole site with known stratigraphy. Eight HVSR (Horizontal to Vertical Spectral Ratio, Nakamura, 1989) were carried out, and thus a first sketch of the buried valley floor along a longitudinal profile of about 5 km was depicted. The values of the derived bedrock depth allow to quantify the differences in thickness between the alluvial deposits and the Moscardo Torrent fan deposits. This information helps to address the contribution of the debris-flow processes in damming the upper But River during the last five centuries. The results confirm the role of debris-flow deposits from the Moscardo Torrent in shaping the morphology of the valley floor of But River and show suitability of an integrated approach, encompassing log stratigraphy, geophysical surveys and analysis of historical documents, for gaining insights on the evolution of alpine valleys. Reference Nakamura, Y., 1989. A method for dynamic characteristic estimation of subsurface using microtremor on the ground surface. Quarterly Report of Railway Technical Research Institute, 30(1): 25-33.

  8. 3-D architecture modeling using high-resolution seismic data and sparse well control: Example from the Mars {open_quotes}Pink{close_quotes} reservoir, Mississippi Canyon Area, Gulf of Mexico

    Chapin, M.A.; Tiller, G.M.; Mahaffie, M.J.

    1996-12-31

    Economic considerations of the deep-water turbidite play, in the Gulf of Mexico and elsewhere, require large reservoir volumes to be drained by relatively few, very expensive wells. Deep-water development projects to date have been planned on the basis of high-quality 3-D seismic data and sparse well control. The link between 3-D seismic, well control, and the 3-D geological and reservoir architecture model are demonstrated here for Pliocene turbidite sands of the {open_quotes}Pink{close_quotes} reservoir, Prospect Mars, Mississippi Canyon Areas 763 and 807, Gulf of Mexico. This information was used to better understand potential reservoir compartments for development well planning.

  9. Investigation of data acquisition parameters for Minami Noshiro 3D experiment using 3D seismic modeling; Sanjigen hado denpa modeling wo riyoshita Minami Noshiro sanjigen jishin tansa data shutoku parameter no kento

    Tanaka, H.; Nakagami, K.; Minegishi, M. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center; Kano, R. [Teikoku Oil Co. Ltd., Tokyo (Japan)

    1996-10-01

    This paper describes how to grasp the characteristics of reflected waves which means how the reflected wave can be received in its magnitude depending on the complicated subsurface structure. Data acquisition parameters were also investigated, as to offset distance distribution and mute setting during the HMO correction. A velocity structure model was prepared for an area of 9km{times}8km including the given 3D seismic exploration area at Minami Noshiro, Akita Prefecture. For the geological sequence used for the velocity structure model, three formations, i.e., Katsurane Formation, Funakawa Formation, and Onagawa Formation, were inputted in an order from the shallower depth on the basis of the depth structure profile obtained from the previous data. Ray tracing was calculated by means of the two-dot dashed line tracing method. For this method, amplitude as well as travel time of waves can be calculated at the same time. This was effective for grasping the magnitude of reflected wave on simulating the traced data. For the velocity structure model used in this study, existing data inputted were old, which limited the quantity of information. However, this model would sufficiently contribute to the verification of survey design and the determination of optimal layout. 1 ref., 3 figs.

  10. 3D Seismic Imaging through Reverse-Time Migration on Homogeneous and Heterogeneous Multi-Core Processors

    Mauricio Araya-Polo

    2009-01-01

    Full Text Available Reverse-Time Migration (RTM is a state-of-the-art technique in seismic acoustic imaging, because of the quality and integrity of the images it provides. Oil and gas companies trust RTM with crucial decisions on multi-million-dollar drilling investments. But RTM requires vastly more computational power than its predecessor techniques, and this has somewhat hindered its practical success. On the other hand, despite multi-core architectures promise to deliver unprecedented computational power, little attention has been devoted to mapping efficiently RTM to multi-cores. In this paper, we present a mapping of the RTM computational kernel to the IBM Cell/B.E. processor that reaches close-to-optimal performance. The kernel proves to be memory-bound and it achieves a 98% utilization of the peak memory bandwidth. Our Cell/B.E. implementation outperforms a traditional processor (PowerPC 970MP in terms of performance (with an 15.0× speedup and energy-efficiency (with a 10.0× increase in the GFlops/W delivered. Also, it is the fastest RTM implementation available to the best of our knowledge. These results increase the practical usability of RTM. Also, the RTM-Cell/B.E. combination proves to be a strong competitor in the seismic arena.

  11. 3-D crustal P-wave velocity tomography of the Italian region using local and regional seismicity data

    F. M. Mele

    1995-06-01

    Full Text Available A tomographic experiment was performed in the Italian region using local and regional arrivaI times of p and S seismological phases selected from the Italian National Bulletin in the time interval 1984-1991. We deter- mined a 3-D crustal P-wave velocity model using a simultaneous inversion method that iteratively re1ocates the hypocenters and computes the unknown model parameters. A fast two-point ray tracing algorithm was adopted to compute the ray paths and travel times of P", S", P g' Sg phases with good accuracy. Synthetic tests were performed using the "true" hypocenter and station distribution to rough1y evaluate the extension of the areas most densely spanned by the ray paths; the agreement between synthetic and computed models is more satisfactory at Moho depths than in the upper crust. The qua1ity of the model resulting from inversion of real data is examined by the ca1culation of the Spread Function (Toomey and Foulger, 1989. The 3-D crustal P-wave velocity mode1 of the Italian region shows remarkab1e trends at Moho depths: the areas east of the Apennines call for positive adjustments of the initial velocity va1ue, while the west region shows negative ad- justments. The correspondence among the main features of the velocity field, the map of Moho isobaths and the map of the gravity anoma1ies is also outlined.

  12. The Complete (3-D) Co-Seismic Displacements Using Point-Like Targets Tracking With Ascending And Descending SAR Data

    Hu, Xie; Wang, Teng; Liao, Mingsheng

    2013-12-01

    SAR Interferometry (InSAR) has its unique advantages, e.g., all weather/time accessibility, cm-level accuracy and large spatial coverage, however, it can only obtain one dimensional measurement along line-of-sight (LOS) direction. Offset tracking is an important complement to measure large and rapid displacements in both azimuth and range directions. Here we perform offset tracking on detected point-like targets (PT) by calculating the cross-correlation with a sinc-like template. And a complete 3-D displacement field can be derived using PT offset tracking from a pair of ascending and descending data. The presented case study on 2010 M7.2 El Mayor-Cucapah earthquake helps us better understand the rupture details.

  13. Down-hole seismic survey system with fiber-optic accelerometer sensor array for 3-dimensions vertical seismic profile (3D-VSP)

    Zou, Qilin; Wang, Liwei; Pang, Meng; Tu, Dongsheng; Zhang, Min; Liao, Yanbiao

    2006-08-01

    We demonstrated a down-hole seismic survey system that can be applied in three dimensions vertical seismic profile (VSP) detection in petroleum exploration. The results of experiments show that the system has a dynamic measurement range of 80db (ratio of maximum to minimum value) and the total delay for signal collection, process and communication is less than 200ms @ 2k bit sample rates. An array consisting of six fiber-optic accelerometers (receivers) is applied in this system. Each receiver is comprised of three fiber-optic Michelson interferometers. In order to meet the requirements of high precision and real-time measurement, the high-speed DSP chips are employed to realize the algorithms of signal filters and Phase Generated Carrier (PGC) demodulation to obtain the seismic information. Multi-ARM CPUs are introduced into the system to design the fiber-optic accelerometer array controller and the receiver array local bus that are used for real-time data communication between the multi-level receivers and controller. The system interface for traditional ELIS Down-hole Instrument Bus (EDIB) is designed by the use of FPGA so that our system can attach to EDIB and cooperate with other instruments. The design and experiments of the system are given in this paper in detail.

  14. Earthquakes in Action: Incorporating Multimedia, Internet Resources, Large-scale Seismic Data, and 3-D Visualizations into Innovative Activities and Research Projects for Today's High School Students

    Smith-Konter, B.; Jacobs, A.; Lawrence, K.; Kilb, D.

    2006-12-01

    The most effective means of communicating science to today's "high-tech" students is through the use of visually attractive and animated lessons, hands-on activities, and interactive Internet-based exercises. To address these needs, we have developed Earthquakes in Action, a summer high school enrichment course offered through the California State Summer School for Mathematics and Science (COSMOS) Program at the University of California, San Diego. The summer course consists of classroom lectures, lab experiments, and a final research project designed to foster geophysical innovations, technological inquiries, and effective scientific communication (http://topex.ucsd.edu/cosmos/earthquakes). Course content includes lessons on plate tectonics, seismic wave behavior, seismometer construction, fault characteristics, California seismicity, global seismic hazards, earthquake stress triggering, tsunami generation, and geodetic measurements of the Earth's crust. Students are introduced to these topics through lectures-made-fun using a range of multimedia, including computer animations, videos, and interactive 3-D visualizations. These lessons are further enforced through both hands-on lab experiments and computer-based exercises. Lab experiments included building hand-held seismometers, simulating the frictional behavior of faults using bricks and sandpaper, simulating tsunami generation in a mini-wave pool, and using the Internet to collect global earthquake data on a daily basis and map earthquake locations using a large classroom map. Students also use Internet resources like Google Earth and UNAVCO/EarthScope's Jules Verne Voyager Jr. interactive mapping tool to study Earth Science on a global scale. All computer-based exercises and experiments developed for Earthquakes in Action have been distributed to teachers participating in the 2006 Earthquake Education Workshop, hosted by the Visualization Center at Scripps Institution of Oceanography (http

  15. Pseudo-random data acquisition geometry in 3D seismic survey; Sanjigen jishin tansa ni okeru giji random data shutoku reiauto ni tsuite

    Minegishi, M.; Tsuburaya, Y. [Japan National Oil Corp., Tokyo (Japan). Technology Research Center

    1996-10-01

    Influence of pseudo-random geometry on the imaging for 3D seismic exploration data acquisition has been investigate using a simple model by comparing with the regular geometry. When constituting wave front by the interference of elemental waves, pseudo-random geometry data did not always provide good results. In the case of a point diffractor, the imaging operation, where the constituted wave front was returned to the point diffractor by the interference of elemental waves for the spatial alias records, did not always give clear images. In the case of multi point diffractor, good images were obtained with less noise generation in spite of alias records. There are a lot of diffractors in the actual geological structures, which corresponds to the case of multi point diffractors. Finally, better images could be obtained by inputting records acquired using the pseudo-random geometry rather than by inputting spatial alias records acquired using the regular geometry. 7 refs., 6 figs.

  16. Deep reflection structure imaged by the 2008 3D seismic reflection Survey at the RIDGE- 2000 East Pacific Rise Integrated Studies Site

    Nedimović, M. R.; Carbotte, S. M.; Mutter, J. C.; Canales, P. J.; Carton, H.; Aghaei, O.; Marjanović, M.; Newman, K. R.; Hu, M.; Stowe, L.

    2008-12-01

    The first multi-source and multi-streamer 3D seismic reflection experiment carried out using academic resources was done aboard the R/V Marcus G. Langseth in Summer 2008 during cruise MGL0812. The targeted area was the RIDGE-2000 Integrated Studies Site at the East Pacific Rise. Our primary 3D survey grid extends from about 9° 57'N to 9° 42'N, with a smaller grid just to the south covering approximately from 9° 40'N to 9° 37.5'N. Additionally, about 1 and 0.5 km wide across-ridge-axis swaths of data were collected at 9° 36'N and 9°30'N respectively, as well as an along-ridge-axis swath about 1 km wide and extending from 10° 05'N to 9° 40'N. We here focus on a preliminary analysis of the reflection structure imaged within the lower crust and uppermost mantle. Moho reflection arrivals are imaged through much of the investigated area. The character of Moho reflection events varies from simple, single reflection wavelet to more complex arrivals indicating spatial changes in structure within the Moho transition zone. Particularly strong Moho reflections are observed in the southern half of the main 3D grid. In places, Moho reflection event appears to extend across the ridge axis potentially suggesting "zero-age" Moho development. Weak Moho arrivals are found at the north end of the main 3D box and within the smaller box to the south. Most notable place lacking Moho reflections is the Lamont seamount area where Moho is not observed on either side of the ridge axis, although the area lacking Moho reflections is wider on the western ridge flank. Further south, along the across-ridge-axis swaths, Moho reflections again become more pronounced. A suit of what mostly appear to be reflection events is recognized between the AMC and Moho. Many of them do not appear to be multiples, and their origin is not well understood. Possible origins for these events include: lower boundary of the AMC, S-converted waves, and lower crustal melt lenses. Along sections of the two 3D

  17. Application of 3D Seismic Exploration in Kyrgyz Coal Mine%海孜煤矿三维地震勘探的应用研究

    王国方

    2014-01-01

    This study used 3-D seismic exploration techniques in the Kyrgyz Coal mine's exploration area map geological exploration,through the geological conditions,technical methods,the analysis of engineering measures,to obtain a better quality of raw data. And then choose the reasonable processing method to analysis and explain the seismic data. At last, find out the fold,fault, magmatic rocks, coal thickNess tectonic features completing the geological tasks perfectly.%本次研究将三维地震勘探技术应用于海孜煤矿的地质勘探,通过对地质条件、技术方法及工程措施等方面的分析,最终获得了质量较好的原始资料,再选用合理的处理方法,对地震资料进行分析与解释,最终查明了褶曲、断层、岩浆岩及煤厚等构造特征,完成了勘探任务。

  18. Application of surface wave travel times and amplitude ratios interpreted through a 3D crustal model to locate and characterize regional seismic events in the US

    Tian, Y.; Ritzwoller, M. H.; Shen, W.; Levshin, A. L.; Barmin, M. P.

    2014-12-01

    The error in the epicentral location of crustal earthquakes across the contiguous US is on the order of 10 km due to the inability of 1D seismic velocity models to capture regional body wave travel time variations. New high resolution 3D models of the crust and uppermost mantle have been constructed recently across the US by inverting surface wave dispersion from ambient noise and earthquakes, receiver functions, and Rayleigh wave H/V ratios using USArray data [e.g., Shen et al., 2013]. These are mostly S-wave models of the lithosphere, however, which are not optimal for predicting regional P-wave travel times. We explore the use of observations of surface waves to improve regional event characterization because the new 3D models are constructed explicitly to model their behavior. In particular, we use measurements of group and phase time delays and the amplitude ratio between different periods of surface waves to estimate the moment tensor, the epicentral location and the earthquake depth. Preliminary estimates of these variables are determined through a simulated annealing algorithm. Afterward, a Bayesian Monte Carlo method is applied to estimate the posterior distribution of all variables in order to assess uncertainties in source characteristics. The reliability and limitations of the location method are tested by systematic relocation of earthquakes across the contiguous US.

  19. Do fault-related folds follow the same scaling law as their associated faults? A study using 3D seismic reflection data

    Pitcher, Eleanor; Imber, Jonathan

    2016-04-01

    Fractal distributions are largely agreed to follow a power-law distribution. Power-law scaling relationships describe the size distribution of fault lengths or displacements. Being able to identify these scaling properties provides a powerful tool for predicting the numbers of geological structures, such as small-scale faults in sedimentary basins that are below the resolution of seismic reflection data. The aim of this study is to determine whether fault-related folds follow the same power law scaling properties, or if they follow a different scaling law. We use TrapTester to interpret a 3D seismic volume from the Gulf of Mexico to construct fault planes and cut-off lines along selected horizons in the vicinity of fault upper tip lines. Fault-related folds are particularly well developed above steeply plunging tip lines, but are discontinuous along the strike of the fault plane. Folding is less well developed on horizons that intersect, or lie close to, the locus of maximum throw (bullseye) of the fault plane. We then measured fold amplitudes and fault throws across these same horizons using a one-dimensional multi-line sampling approach. Graphs of fault throw and fold amplitude vs. distance parallel to fault strike show that folds occur where there is no resolvable fault throw, and that fault throw and fold amplitudes show an approximately inverse relationship. Close to the locus of maximum throw, there is largely just faulting, whilst at the upper tip line folding predominates. By plotting cumulative frequency against throw for the fault and fold data we can investigate whether the data follow a power law, log normal or exponential distribution. Plotting the data on log vs. log (power law), linear vs. log (log normal) and log vs. linear (exponential) axes allow us to establish which displays the best "straight-line fit". We observed that the fault throw data satisfied a straight-line on a log vs. log graph - implying a power law distribution - and also returned

  20. 3D seismic geomorphology of mass transport complexes in a foredeep basin: Examples from the Pleistocene of the Central Adriatic Basin (Mediterranean Sea)

    Dalla Valle, Giacomo; Gamberi, Fabiano; Rocchini, Patrizia; Minisini, Daniel; Errera, Alessia; Baglioni, Luca; Trincardi, Fabio

    2013-08-01

    Three-dimensional (3D) seismic-reflection data has shed light on the character of a series of mass transport complexes (MTCs) emplaced during the Pleistocene in the Pescara Basin (Central Adriatic Sea, Italy). The Pescara Basin is the Plio-Pleistocene inner foredeep of the Central Apennines orogen, which was filled by a rapidly prograding, margin-scale clinoforms system. Three MTCs punctuate the normal turbiditic and hemipelagic sedimentary succession of the Pescara Basin foredeep. MTC_0 is the oldest one and covers an area of around 74 km2. It is composed of three different mass transport deposits (MTDs) resulting from individual collapses that involved a shelf-edge delta during a period of relative sea level rise. MTC_1, the intermediate age MTC, is the largest one, with an area of 90 km2. It has a 10 km wide cookie-bite headwall region that indents the upper slope and, in places, reaches the continental shelf-break. MTC_1 is made up of four laterally and vertically stacked MTDs which are the result of a composite set of failures that migrated progressively upslope in a sedimentary setting dominated by contourite deposits. MTC_2 is the youngest and the smallest one, with an area of 55 km2. It has a 5 km long headwall confined in correspondence with a sedimentary bulge developed in the upper slope. Its geomorphic setting leads us to consider two different episodes of failure rooted at different depths. The investigation of the MTCs, through the coupling of 3D seismic geomorphology, seismic facies analysis and rollover trajectory analysis, reveals that the type of sedimentary environment, the rate of sediment accumulation, the source region and the depth of rooting of the failure, are the major controlling factors on MTC evolution and emplacement. Each MTC of the Pescara Basin foredeep is generally confined within a discrete clinotheme. Finally, the rollover trajectory analysis has shown that, in the PB foredeep, a sediment failure can possibly occur at any

  1. On Boreholes and PBO Borehole Strain

    Gladwin, M. T.; Mee, M. W.

    2003-12-01

    Borehole tensor strainmeters (GTSM) installed in Australia and California have established a baseline of data spanning more than twenty years. The current baseline of data allows characterisation of a moderate number of instruments in a range of very different environments in a way which defines reasonable performance expectations for the upcoming PBO deployments. A generic understanding of effects which result from the process of installation of the instrument in a stressed rock mass emerges. This indicates that, provided due allowance is made for experimentally determined borehole recovery effects, the contribution of borehole strain meters more than adequately fills the observational gap between high stability/long term geodetic measurements of strain and strain rates and high resolution/high frequency seismic observations of earth deformation processes. The various strain relief processes associated with the installation procedures and borehole recovery effects associated with pre-existing stress fields will be documented. Procedures for calibration of the total borehole inclusion and for progressive removal of effects due to rock anisotropy and visco-elastic creep of the grout and rock close to the borehole from far field tectonic effects will be defined and illustrated with examples. Observed deviations from these processes will be shown to be small and consistent with otherwise observed or implied fault motions. Full details of these borehole induced processes are, however, difficult to determine in the early years following installation, particularly if there is significant tectonic activity at the time. Once quantified for each site, the effects can be robustly removed from data streams.

  2. Sydney-Gunnedah-Bowen Basin deep 3D structure

    Danis, Cara

    2012-01-01

    Studies of the Sydney-Gunnedah-Bowen Basin (SGBB), one of the largest extensional rift sedimentary basins on the east coast of Australia, lack an understanding of the 3D upper crustal structure. Understanding of the subsurface structure is essential for many areas of resource exploration, development and management, as well as scientific research. Geological models provide a way to visualise and investigate the subsurface structure. The integrated regional scale gravity modelling approach, which uses boreholes and seismic data constraints, provides an understanding of the upper crustal structure and allows the development of a 3D geological model which can be used as the architectural framework for many different applications. This work presents a 3D geological model of the SGBB developed for application in high resolution thermal models. It is the culmination of geological surfaces derived from the interpolation of previous regional scale 2D gravity models and numerous borehole records. The model outlines the basement structure of the SGBB and provides information on depth to basement, depth to basal volcanics and thickness of overlying sediments. Through understanding the uncertainties, limitations, confidence and reliability of this model, the 3D geological model can provide the ideal framework for future research.

  3. Application of 3D Seismic Prospecting in Chaochuan Coalmine Deep Part Exploration%三维地震技术在朝川矿深部勘探中的应用

    左明星

    2012-01-01

    平顶山煤业(集团)有限公司朝川矿主采煤层埋藏较深,为掌握其深部地质构造及主采煤层的赋存情况,特别是断层对深部煤层的破坏程度,对该区进行了三维地震勘探.针对勘探区地表条件复杂,激发条件变化较大,成孔难等问题,采用人工成孔、机械成孔、单井、多井等措施进行激发试验,确定了该区的最佳激发参数为井深1~3m、药量0.6~1.2kg的中点激发方式.根据勘探区的地理条件,采用束状8线8炮制观测系统,16次覆盖.为保证野外资料的连续性和覆盖次数的稳定性,在村庄附近除采用纵横向变观措施外,还采用了“双L”排列方法.利用数据空间属性、人工静校正、精细速度谱分析等地震处理技术,获得了高质量的三维地震数据体,并通过人工交互地震解释系统对断层进行了有效识别,取得较好的结果.%The main mineable coal seams in the Chaochuan coalmine, Pingdingshan Coal Industry Group Co. Ltd. are rather deeply buried. In order to know well the deep part geological structure and main mineable coal seam occurrences, especially, the degree of fault destruction on coal seams, the 3D seismic prospecting has been used. In allusion to issues of complicated surface conditions in prospecting area, variation of shoot conditions, hard to complete a borehole etc., thus carried out shooting tests using measures of manual and mechanical boring, single hole and multiple holes, and have determined optimum shooting parameters of hole depth 1~3m, explosive dosage 0.6-1.2kg median shooting mode. According to geographical conditions of the prospecting area, the bunching 8 lines 8 shots field setup, and 16 folds have been used. To ensure continuity of field data and fold stability, besides using longitudinal and transversal shotpoint transferring, also the "dual L" spread geometry have been used. By the agency of data space attribute, manual statics, precision velocity spectrum

  4. A Detailed 3D Seismic Velocity Structure of the Subducting Pacific Slab Beneath Hokkaido, Tohoku and Kanto, Japan, by Double-Difference Tomography

    Tsuji, Y.; Nakajima, J.; Kita, S.; Okada, T.; Matsuzawa, T.; Hasegawa, A.

    2007-12-01

    Three-dimensional heterogeneous structure beneath northeastern (NE) Japan has been investigated by previous studies and an inclined seismic low-velocity zone is imaged in the mantle wedge sub-parallel to the down-dip direction of the subducting slab (Zhao et al., 1992, Nakajima et al., 2001). However, the heterogeneous structure within the slab has not been well studied even though it is very important to understand the whole process of water transportation from the slab to the surface. Here we show a detailed 3D seismic velocity structure within the subducted Pacific slab around Japan and propose a water-transportation path from the slab to the mantle wedge. In this study, we estimated 3D velocity structure within the Pacific slab by the double-difference tomography (Zhang and Thurber, 2003). We divided the study area, from Hokkaido to Kanto, into 6 areas due to the limitation of memory and computation time. In each area, arrival-time data of 7,500-17,000 events recorded at 70-170 stations were used in the analysis. The total number of absolute travel-time data was about 140,000-312,000 for P wave and 123,000-268,000 for S wave, and differential data were about 736,000-1,920,000 for P wave and 644,000-1,488,000 for S wave. Horizontal and vertical grid separations are 10-25 km and 6.5 km, respectively. RMS residuals of travel times for P wave decreased from 0.23s to 0.09s and for S wave from 0.35s to 0.13s. The obtained results are as follows: (1) a remarkable low-Vs zone exists in the uppermost part of the subducting slab, (2) it extends down to a depth of about 80 km, (3) the termination of this low-Vs zone almost corresponds to the "seismic belt" recently detected in the upper plane of the double seismic zone (Kita et al.,2006; Hasegawa et al., 2007), (4) at depths deeper than 80 km, a low-Vs and high-Vp/Vs zone is apparently distributed in the mantle wedge, immediately above the slab crust. We consider that these features reflect water-transportation processes

  5. Flow dynamics and sedimentation of lateral accretion packages in sinuous deep-water channels: A 3D seismic case study from the northwestern South China Sea margin

    Li, Shengli; Gong, Chenglin

    2016-07-01

    The current study uses 3D seismic data to document architectural styles and flow dynamics of lateral accretion packages (LAPs) associated with sinuous deep-water channels, contributing to a better understanding of flow processes and sedimentation associated with LAPs. The documented LAPs underwent three main stages of architectural evolution, including the early incision stages characterized by intense downcutting, active migration stages characterized by active migration and avulsion of the individual channels, and late abandonment stages characterized by the termination of sediment gravity-flows and LAP growth. These three stages of LAP growth repeated through time, yielding a fining-upward pattern from sandy channel-fill turbidites, into sand-mud couplets, all capped by muddy turbidites. A river-reversed helical flow circulation was created by an imbalance, through the flow depth, of inwardly directed pressure gradient forces near the bed and outwardly directed centrifugal forces near the surface. It consists of low-velocity cores near the outer banks and low-velocity cores along the inner banks. Such river-reversed helical flow pattern is evidenced by volumetrically extensive LAPs and toplap and downlap terminations along the gentle banks and by aerially restricted, seismically unresolvable levees and truncation terminations near the steep banks. This river-reversed helical flow circulation favors asymmetric intra-channel deposition characterized by inner bank deposition versus outer bank erosion, and which, in turn, forced individual channels to consistently migrate towards outer banks, resulting in significant asymmetric cross-channel profiles with aerially extensive LAPs along inner banks.

  6. Fluvial response to active extension: evidence from 3D seismic data from the Frio Formation (Oligo-Miocene) of the Texas Gulf of Mexico Coast, USA

    J.R. Maynard [ExxonMobil Upstream Research Company, Houston, TX (United States)

    2006-06-15

    Tectonic deformation of the land surface is known to influence the gradient, water and sediment discharge and the grain-size of modern fluvial systems. Any change in these variables alters the equilibrium of a fluvial system, potentially causing a change in channel morphology. 3D seismic data from the Tertiary (Miocene) age, Upper Frio Formation, Kelsey Field, South Texas, in the US are used to examine changing fluvial channel morphology through time during a period of active growth of a rollover anticline in the hanging wall of a normal fault (the Vicksburg Fault). The studied interval varies between 22 and 47 m thick, and spans several hundred thousand years. It consists of an alternation of fluvial sandstones, overbank mudstones and coal. Seismic extractions show the evolution of sinuous fluvial channels during a phase of growth fault activity. Prior to growth, a single sinuous channel is imaged. During growth, the fluvial system became decapitated by a developing rollover anticline, and a highly sinuous drainage network formed, with frequent avulsion events, headward propagation of streams and related stream capture. Increased channel sinuosity was spatially associated with increased avulsion frequency in the area down dip to the east of the rollover anticline, more than 10 km from the active fault. More than 25 m of relative accommodation developed on the flank of the growing rollover anticline compared with on the crest. The increased channel sinuosity is interpreted as reflecting an increase in longitudinal valley slope analogous to observations made in flume experiments and modern river systems. The increase in avulsion frequency is attributed to increased aggradation as the rivers adjusted back to equilibrium grade following the increase in slope.

  7. Quantifying uncertainties on the solution model of seismic tomography; Quelle confiance accorder au modele solution de la tomographie de reflexion 3D?

    Duffet, C.

    2004-12-01

    Reflection tomography allows the determination of a velocity model that fits the travel time data associated with reflections of seismic waves propagating in the subsurface. A least-square formulation is used to compare the observed travel times and the travel times computed by the forward operator based on a ray tracing. This non-linear optimization problem is solved classically by a Gauss-Newton method based on successive linearization of the forward operator. The obtained solution is only one among many possible models. Indeed, the uncertainties on the observed travel times (resulting from an interpretative event picking on seismic records) and more generally the under-determination of the inverse problem lead to uncertainties on the solution. An a posteriori uncertainty analysis is then crucial to delimit the range of possible solutions that fit, with the expected accuracy, the data and the a priori information. A linearized a posteriori analysis is possible by an analysis of the a posteriori covariance matrix, inverse of the Gauss-Newton approximation of the matrix. The computation of this matrix is generally expensive (the matrix is huge for 3D problems) and the physical interpretation of the results is difficult. Then we propose a formalism which allows to compute uncertainties on relevant geological quantities for a reduced computational time. Nevertheless, this approach is only valid in the vicinity of the solution model (linearized framework) and complex cases may require a non-linear approach. An experimental approach consists in solving the inverse problem under constraints to test different geological scenarios. (author)

  8. 3D architecture modeling of reservoir compartments in a Shingled Turbidite Reservoir using high-resolution seismic data and sparse well control, example from Mars {open_quotes}Pink{close_quotes} reservoir, Mississippi Canyon Area, Gulf of Mexico

    Chapin, M.A.; Mahaffie, M.J.; Tiller, G.M. [Shell Exploration and Production Technology Co., Houston, TX (United States)

    1996-12-31

    Economics of most deep-water development projects require large reservoir volumes to be drained with relatively few wells. The presence of reservoir compartments must therefore be detected and planned for in a pre-development stage. We have used 3-D seismic data to constrain large-scale, deterministic reservoir bodies in a 3-D architecture model of Pliocene-turbidite sands of the {open_quotes}E{close_quotes} or {open_quotes}Pink{close_quotes} reservoir, Prospect Mars, Mississippi Canyon Areas 763 and 807, Gulf of Mexico. Reservoir compartmentalization is influenced by stratigraphic shingling, which in turn is caused by low accommodation space predentin the upper portion of a ponded seismic sequence within a salt withdrawal mini-basin. The accumulation is limited by updip onlap onto a condensed section marl, and by lateral truncation by a large scale submarine erosion surface. Compartments were suggested by RFT pressure variations and by geochemical analysis of RFT fluid samples. A geological interpretation derived from high-resolution 3-D seismic and three wells was linked to 3-D architecture models through seismic inversion, resulting in a reservoir all available data. Distinguishing subtle stratigraphical shingles from faults was accomplished by detailed, loop-level mapping, and was important to characterize the different types of reservoir compartments. Seismic inversion was used to detune the seismic amplitude, adjust sandbody thickness, and update the rock properties. Recent development wells confirm the architectural style identified. This modeling project illustrates how high-quality seismic data and architecture models can be combined in a pre-development phase of a prospect, in order to optimize well placement.

  9. 3D architecture modeling of reservoir compartments in a Shingled Turbidite Reservoir using high-resolution seismic data and sparse well control, example from Mars [open quotes]Pink[close quotes] reservoir, Mississippi Canyon Area, Gulf of Mexico

    Chapin, M.A.; Mahaffie, M.J.; Tiller, G.M. (Shell Exploration and Production Technology Co., Houston, TX (United States))

    1996-01-01

    Economics of most deep-water development projects require large reservoir volumes to be drained with relatively few wells. The presence of reservoir compartments must therefore be detected and planned for in a pre-development stage. We have used 3-D seismic data to constrain large-scale, deterministic reservoir bodies in a 3-D architecture model of Pliocene-turbidite sands of the [open quotes]E[close quotes] or [open quotes]Pink[close quotes] reservoir, Prospect Mars, Mississippi Canyon Areas 763 and 807, Gulf of Mexico. Reservoir compartmentalization is influenced by stratigraphic shingling, which in turn is caused by low accommodation space predentin the upper portion of a ponded seismic sequence within a salt withdrawal mini-basin. The accumulation is limited by updip onlap onto a condensed section marl, and by lateral truncation by a large scale submarine erosion surface. Compartments were suggested by RFT pressure variations and by geochemical analysis of RFT fluid samples. A geological interpretation derived from high-resolution 3-D seismic and three wells was linked to 3-D architecture models through seismic inversion, resulting in a reservoir all available data. Distinguishing subtle stratigraphical shingles from faults was accomplished by detailed, loop-level mapping, and was important to characterize the different types of reservoir compartments. Seismic inversion was used to detune the seismic amplitude, adjust sandbody thickness, and update the rock properties. Recent development wells confirm the architectural style identified. This modeling project illustrates how high-quality seismic data and architecture models can be combined in a pre-development phase of a prospect, in order to optimize well placement.

  10. Structure Segmentation and Transfer Faults in the Marcellus Shale, Clearfield County, Pennsylvania: Implications for Gas Recovery Efficiency and Risk Assessment Using 3D Seismic Attribute Analysis

    Roberts, Emily D.

    The Marcellus Shale has become an important unconventional gas reservoir in the oil and gas industry. Fractures within this organic-rich black shale serve as an important component of porosity and permeability useful in enhancing production. Horizontal drilling is the primary approach for extracting hydrocarbons in the Marcellus Shale. Typically, wells are drilled perpendicular to natural fractures in an attempt to intersect fractures for effective hydraulic stimulation. If the fractures are contained within the shale, then hydraulic fracturing can enhance permeability by further breaking the already weakened rock. However, natural fractures can affect hydraulic stimulations by absorbing and/or redirecting the energy away from the wellbore, causing a decreased efficiency in gas recovery, as has been the case for the Clearfield County, Pennsylvania study area. Estimating appropriate distances away from faults and fractures, which may limit hydrocarbon recovery, is essential to reducing the risk of injection fluid migration along these faults. In an attempt to mitigate the negative influences of natural fractures on hydrocarbon extraction within the Marcellus Shale, fractures were analyzed through the aid of both traditional and advanced seismic attributes including variance, curvature, ant tracking, and waveform model regression. Through the integration of well log interpretations and seismic data, a detailed assessment of structural discontinuities that may decrease the recovery efficiency of hydrocarbons was conducted. High-quality 3D seismic data in Central Pennsylvania show regional folds and thrusts above the major detachment interval of the Salina Salt. In addition to the regional detachment folds and thrusts, cross-regional, northwest-trending lineaments were mapped. These lineaments may pose a threat to hydrocarbon productivity and recovery efficiency due to faults and fractures acting as paths of least resistance for induced hydraulic stimulation fluids

  11. Seismic site characterization of an urban dedimentary basin, Livermore Valley, California: Site tesponse, basin-edge-induced surface waves, and 3D simulations

    Hartzell, Stephen; Leeds, Alena L.; Ramirez-Guzman, Leonardo; Allen, James P.; Schmitt, Robert G.

    2016-01-01

    Thirty‐two accelerometers were deployed in the Livermore Valley, California, for approximately one year to study sedimentary basin effects. Many local and near‐regional earthquakes were recorded, including the 24 August 2014 Mw 6.0 Napa, California, earthquake. The resulting ground‐motion data set is used to quantify the seismic response of the Livermore basin, a major structural depression in the California Coast Range Province bounded by active faults. Site response is calculated by two methods: the reference‐site spectral ratio method and a source‐site spectral inversion method. Longer‐period (≥1  s) amplification factors follow the same general pattern as Bouguer gravity anomaly contours. Site response spectra are inverted for shallow shear‐wave velocity profiles, which are consistent with independent information. Frequency–wavenumber analysis is used to analyze plane‐wave propagation across the Livermore Valley and to identify basin‐edge‐induced surface waves with back azimuths different from the source back azimuth. Finite‐element simulations in a 3D velocity model of the region illustrate the generation of basin‐edge‐induced surface waves and point out strips of elevated ground velocities along the margins of the basin.

  12. 3D modeling of stratigraphic units and simulation of seismic facies in the Lion gulf margin; Modelisation 3D des unites stratigraphiques et simulation des facies sismiques dans la marge du golfe du Lion

    Chihi, H.

    1997-05-12

    This work aims at providing a contribution to the studies carried out on reservoir characterization by use of seismic data. The study mainly consisted in the use of geostatistical methods in order to model the geometry of stratigraphic units of the Golfe du Lion margin and to simulate the seismic facies from high resolution seismic data. We propose, for the geometric modelling, a methodology based on the estimation of the surfaces and calculation afterwards of the thicknesses, if the modelling of the depth is possible. On the other hand the method consists in estimating the thickness variable directly and in deducing the boundary surfaces afterwards. In order to simulate the distribution of seismic facies within the units of the western domain, we used the truncated Gaussian method. The used approach gave a satisfactory results, when the seismic facies present slightly dipping reflectors with respect to the reference level. Otherwise the method reaches its limits because of the problems of definition of a reference level which allows to follow the clino-forms. In spite of these difficulties, this simulation allows us to estimate the distribution of seismic facies within the units and then to deduce their probable extension. (author) 150 refs.

  13. Tectonics of North-Central Switzerland: interpretation on the basis on regional seismics, surface geology and deep boreholes

    This report presents the methodology and results of a geological interpretation of Nagra's reflection seismic data (1982-1984) for North-Central Switzerland. The area under investigation, which is covered by the entire network of reflection seismics lines, is outlined by the towns of Schaffhausen/ Zuerich in the east and Saeckingen/Olten in the west. (author) figs., tabs., 439 refs

  14. Application of Seismic Observation Data in Borehole for the Development of Attenuation Equation of Response Spectra on Bedrock

    Ground motion data on seismic bedrock is important, but it is very difficult to obtain such data directly. The data from KiK-net and JNES/SODB is valuable and very useful in developing the attenuation relationship of response spectra on seismic bedrock. NIED has approximately 200 observation points on seismic bedrock with S-wave velocity of more than 2000 m/s in Japan. Using data from observation at these points, a Ground Motion Prediction Equation (GMPE) is under development. (author)

  15. Imaging Magma Under St. Helens (iMUSH): Details of passive-source seismic deployment and preliminary 3-D velocity structure

    Ulberg, C. W.; Creager, K. C.; Moran, S. C.; Abers, G. A.; Denlinger, R. P.; Hotovec-Ellis, A. J.; Vidale, J. E.; Kiser, E.; Levander, A.; Schultz, A.

    2014-12-01

    The imaging Magma Under St. Helens (iMUSH) experiment aims to delineate the extent of the magmatic system beneath Mount St. Helens (MSH) in Washington State. The experiment involves active- and passive-source seismology, magnetotellurics, and geochemistry/petrology. Seventy passive-source broadband seismometers were deployed in a 100-km-diameter array centered on MSH, with an average spacing of 10 km, and a planned duration of two years. The deployment over two weeks in June 2014 involved a group of 18 people split into 6 teams. Approximately half of the seismic stations have aircell batteries and/or pole-mounted solar panels in order to maintain power through deep snow at higher elevations during the winter months. Data will be retrieved 2-4 times a year throughout the duration of the experiment. The first service run performed in mid-July 2014 had a 98.4% data recovery. This is one of the largest wide-aperture two-dimensional arrays covering a volcano anywhere. The active-source portion of the experiment successfully set off 23 shots in late-July 2014. These were recorded clearly at permanent stations run by the Pacific Northwest Seismic Network up to 200 km away, and are expected to be well-recorded on many of the 70 broadband seismometers in addition to the 2500 Reftek "Texans" deployed temporarily for this purpose. For the 2-4 weeks of broadband data collected in July, local earthquakes down to magnitude 0 are recorded across the array, with clear P- and S- arrivals. Earthquakes of this size occur daily within 50 km of MSH. We are keeping a careful catalog of all activity in the region for the duration of the iMUSH experiment. We will pick P- and S-wave travel times at the 70 broadband stations from local earthquakes and active shots, for available data from between June and October 2014. We will also use a tomographic code (Preston et al, 2003, Science) to invert the travel times to obtain preliminary earthquake location and 3-D velocity structure.

  16. The microstructure of sediment-hosted hydrates: evidence from effective medium modelling of laboratory and borehole seismic data

    Minshull, T.A.; Chand, S

    2009-01-01

    Much of our knowledge of hydrate distribution in the subsurface comes from interpretations of remote seismic measurements. A key step in such interpretations is an effective medium theory that relates the seismic properties of a given sediment to its hydrate content. A variety of such theories have been developed; these theories generally give similar results if the same assumptions are made about the extent to which hydrate contributes to the load-bearing sediment frame. We ha...

  17. A Coulomb stress model for induced seismicity distribution due to fluid injection and withdrawal in deep boreholes

    Troiano, Antonio; Di Giuseppe, Maria Giulia; Troise, Claudia; Tramelli, Anna; De Natale, Giuseppe

    2013-10-01

    Fluid injection in and withdrawal from wells are basic procedures in mining activities and deep resources exploitation, such as oil and gas extraction, permeability enhancement for geothermal exploitation and waste fluid disposal. All of these activities have the potential to induce seismicity, as exemplified by the 2006 Basel earthquake (ML 3.4). Despite several decades of experience, the mechanisms of induced seismicity are not known in detail, which prevents effective risk assessment and/or mitigation. In this study, we provide an interpretation of induced seismicity based on computation of Coulomb stress changes that result from fluid injection/withdrawal at depth, mainly focused on the interpretation of induced seismicity due to stimulation of a geothermal reservoir. Seismicity is, theoretically, more likely where Coulomb stress changes are larger. For modeling purposes, we simulate the thermodynamic evolution of a system after fluid injection/withdrawal. The associated changes in pressure and temperature are subsequently considered as sources of incremental stress changes, which are then converted to Coulomb stress changes on favourably oriented faults, taking into account the background regional stress. Numerical results are applied to the water injection that was performed to create the fractured reservoir at the enhanced-geothermal-system site, Soultz-sous-Forets (France). Our approach describes well the observed seismicity, and provides an explanation for the different behaviors of a system when fluids are injected or withdrawn.

  18. Along-strike variations of structural styles in the imbricated Molasse of Salzburg and Upper Austria: a 3-D seismic perspective

    Hinsch, Ralph; Linzer, Hans-Gert

    2010-05-01

    At the southern border of the Northern Alpine Foreland Basin syntectonic deposits (Molasse Sediments) are partly incorporated into Alpine contractional deformation. Along the alpine chain style and timing of this deformation varies significantly. In this study we use one of the largest European on-shore 3-D seismic datasets, spanning the Molasse basin of Upper Austria and Salzburg states, to investigate the along-strike structural architecture of the alpine deformation front. In the Austrian Part of the Molasse basin, foredeep sedimentation started in Upper-Eocene times (Wagner, 1996). The sediments cover the European margin, consisting of a crystalline basement covered by variously thick Mesozoic sediments (Nachtmann und Wagner, 1987). In Oligocene to Lower Miocene times, syntectonic foredeep sedimentation took place in a deep marine environment, comprising an axial channel system (Linzer 2001, DeRuig and Hubbard, 2006). Parts of these syntectonic sediments are subsequently affected by the advancing thrust wedge. Within the study area, three distinct fold-and-thrust belt segments of different structural architecture can be defined. 1) The Perwang Imbricates are a promontory mostly situated in Salzburg at the border to Germany. Complexly deformed small thrust sheets evolve above a detachment horizon situated in Late Cretaceous shaly marls in Oligocene times. Syntectonic piggy-back and thrust top basins evolve (Covault et al. 2008), which are partly affected by subsequent Miocene overthrusting. 2) The Regau Segment is the area west of the Perwang lobe. It is dominated by few number of thrust sheets in the Molasse sediments. Instead, over-thrusting by the alpine wedge (pre-deformed Flysch and Helvetic thrust sheets) dominates. 3) The Sierning Imbricates segment is located further to the east, at the border of Upper Austria to Lower Austria. The structural inventory of this thrust belt is comprises varying numbers of thrust sheets along strike (1-5), ramp

  19. Integrated Tsunami Database: simulation and identification of seismic tsunami sources, 3D visualization and post-disaster assessment on the shore

    Krivorot'ko, Olga; Kabanikhin, Sergey; Marinin, Igor; Karas, Adel; Khidasheli, David

    2013-04-01

    One of the most important problems of tsunami investigation is the problem of seismic tsunami source reconstruction. Non-profit organization WAPMERR (http://wapmerr.org) has provided a historical database of alleged tsunami sources around the world that obtained with the help of information about seaquakes. WAPMERR also has a database of observations of the tsunami waves in coastal areas. The main idea of presentation consists of determining of the tsunami source parameters using seismic data and observations of the tsunami waves on the shore, and the expansion and refinement of the database of presupposed tsunami sources for operative and accurate prediction of hazards and assessment of risks and consequences. Also we present 3D visualization of real-time tsunami wave propagation and loss assessment, characterizing the nature of the building stock in cities at risk, and monitoring by satellite images using modern GIS technology ITRIS (Integrated Tsunami Research and Information System) developed by WAPMERR and Informap Ltd. The special scientific plug-in components are embedded in a specially developed GIS-type graphic shell for easy data retrieval, visualization and processing. The most suitable physical models related to simulation of tsunamis are based on shallow water equations. We consider the initial-boundary value problem in Ω := {(x,y) ?R2 : x ?(0,Lx ), y ?(0,Ly ), Lx,Ly > 0} for the well-known linear shallow water equations in the Cartesian coordinate system in terms of the liquid flow components in dimensional form Here ?(x,y,t) defines the free water surface vertical displacement, i.e. amplitude of a tsunami wave, q(x,y) is the initial amplitude of a tsunami wave. The lateral boundary is assumed to be a non-reflecting boundary of the domain, that is, it allows the free passage of the propagating waves. Assume that the free surface oscillation data at points (xm, ym) are given as a measured output data from tsunami records: fm(t) := ? (xm, ym,t), (xm

  20. Shear wave velocity for the upper 30 m: Combining a 3D voxel model and seismic CPTS for the Groningen gas field, the Netherlands.

    Dambrink, Roula; Gunnink, Jan; Stafleu, Jan; de Lange, Ger; Kruiver, Pauline

    2016-04-01

    The Groningen gas field in the Netherlands is one of the largest gas fields of Europe and has been in production since the 1960's. Due to the progressive depletion of the reservoir, induced seismic activity has increased in recent years. In 2012, an earthquake of magnitude 3.6 initiated further research in prediction and management of risks related to man-induced earthquakes. Last year the government decided to reduce the gas extraction for this reason. One of the topics of concern is the large difference in earthquake-related damage to buildings which, in addition to the distance to the epicenter, appears to be also related to the composition of the shallow subsurface. To improve the spatial distribution of Shear Wave Velocities (Vs) in the shallow subsurface, used for hazard prediction, the Geological Survey of the Netherlands and Deltares constructed a Vs30 map of the upper 30 m of the gas field. In this map a high-resolution geological model (GeoTOP) is combined with seismic cone penetration tests (SCPT) from the area. The GeoTOP model is a 3D voxel model of the upper 50 m, in which each voxel (100x100x0.5 m) is attributed with lithostratigraphy and the most likely lithological class (peat, clay, fine sand, etc.). To obtain statistical distributions (with mean and standard deviation) of Vs for each combination of lithostratigraphical unit and lithoclass, 60 SCPTs were analyzed. In this way, it was possible to assign a specific Vs to each voxel in the model. For each voxel in the stack of voxels that covers the upper 30 m (i.e. 60 voxels), a Vs value was randomly drawn from the statistical distribution of the lithostratigraphical - lithoclass combination it belongs to. The Vs30 for each voxelstack is then calculated using the harmonic mean of the Vs of the 60 voxels. By repeating this procedure 100 times, an (average) Vs30 map and the uncertainty in Vs30 has been constructed. Using the procedure described above we were able to delineate zones with distinct Vs30

  1. Structural interpretation of upper crust of the Khibiny area on the complex of geological and geophysical data and the results of 3D seismic and density modeling

    Zhirov, Dmitry; Glaznev, Victor; Zhirova, Anzhela

    2015-04-01

    The area considered is located in the central part of the Kola Peninsula and represents a part of tectonically compound terrane, consisting of the AR, PR and PZ geological structures of the East of Fennoscandian shield (NW Russia). The Khibiny massif (PZ) intrudes the Archean complexes (the northern contact) and the Paleoproterozoic volcanogenic-sedimentary Imandra-Varzuga complex (southern and SW-contacts). Moreover this district includes several PGE-bearing layered mafic-ultramafic intrusions, which are related with Neo Archaean ÷ Paleoproterozoic rifting and plume activity (LIP). According to the previous conceptions the shape of the Khibiny multiphase pluton is close to the asymmetrical lopolit, characterized by the steep eastern and northern contacts and the gentler south and west contacts. The results of the 3D seismic and density modelling showed two correlated local high-velocity and high-density anomalies with dimensions of 5 x 10 km approximately in central part of the Khibiny massif (1) and close to contact with Imandra-Varzuga sedimentary-volcanic complex (2). The first anomaly cannot be explained by "substance" factor only (titanomagnetite-apatite ore bodies), as it has a structural disconformity to general structure of the pluton. According to the numerous instrumental measurements the actual values of stress are significantly greater than values calculated by weight of rocks. It is important the main normal axis of compressive stress has usually quasi-horizontal position. Thus, the zone of abnormally high tectonic stress is the best explanation for this anomaly. The quick isostatic uplift of the massif after the digression of the last glacier, during which the rocks did not have time to unload, can be a source of the increased horizontal stress. Based on the properties of typical rocks and geological structure of the region the second anomaly is well interpreted by large layered intrusion of Fedorova-Pana type, subsurface of which is cut by Khibiny

  2. CHARACTERISTICS OF THE CRUSTAL MAGMA BODY IN THE 2005-2006 ERUPTION AREA AT 9°50'N ON THE EAST PACIFIC RISE FROM 3D MULTI-CHANNEL SEISMIC DATA

    Carton, H. D.; Carbotte, S. M.; Mutter, J. C.; Canales, J.; Nedimovic, M. R.; Marjanovic, M.; Aghaei, O.; Xu, M.; Han, S.; Stowe, L.

    2009-12-01

    In the summer of 2008 a large 3D multi-channel seismic dataset (expedition MGL0812) was collected over the 9°50’N Integrated Study Site at the East Pacific Rise, providing insight into the architecture of the magmatic system and its relationship with hydrothermal activity and volcanic/dyking events associated with the 2005-06 eruption. The main area of 3D coverage is located between 9°42’N and 9°57’N, spanning ~28km along-axis, and was acquired along 94 (1 partial) prime lines shot across-axis and each ~24km-long. Pre-processing of the data acquired in this area is now well under way, with significant efforts targeted at amplitude spike removal. Current work focuses on setting up the 3D processing sequence up to the stack stage for a small group of inlines (axis-perpendicular grid lines spaced 37.5m apart) located over the “bull’s eye” site at 9°50’N, a sequence that will subsequently be applied to the whole dataset. At the meeting we will present stacked and migrated sections - inlines, crosslines, time slices - obtained through 3D processing. We will discuss results focusing on the characteristics of the axial magma body, whose detailed structure and along-axis segmentation will be resolved by the 3D data.

  3. Characteristic test results of reduced-scale lead and 3D laminated rubber bearings for seismic isolation design of liquid metal reactor

    Yoo, B.; Lee, Jae Han [Korea Atomic Energy Research Institute, Taejon (Korea, Republic of); Kwon, H. S. [Chungnam Univ., Taejon (Korea, Republic of)

    1999-06-01

    Through the fabrications and the tests of reduced scale rubber bearing by several times since 1995, the technology related to the bearings has been improved. In this report, several lead rubber bearings (LLRB) with different lead plug diameters, high damping rubber bearing (HLRB), and 3D-LRB made of UNISON NR (natural rubber) compounds are tested to get the hysteretic characteristics of rubber bearings. Specially, the HLRB and 3D-LRB are tested for the vertical deformation characteristics. All the test data are plotted and analyzed to be compared with design target values such as equivalent horizontal stiffness and equivalent damping ration. The variations of the equivalent horizontal stiffness and damping for the lead and the 3D-LRB are evaluated from test data in the range of 25% to 150% of shear strain in horizontal direction. As increasing the lead plug diameter up to 48 mm, the values of yield load, equivalent stiffness, and equivalent damping are increased, and the maximum damping of 31 % are horizontal performance during compression and shear tests. Through the vertical performance tests of HLRB and 3D-LRB, it is reveal that the vertical stiffness of HLRB is 15.57 ton/mm, which is much lower than target value by 1/4, and the vertical stiffness of 3D-LRB show in the range of 2.17 ton/mm to 4.4 ton/mm, which are higher than the design target 1.25 ton/mm by about 2 times. The vertical equivalent damping of HLRB is 11.48%, but the ones of 3D-LRB show large variations between 8 % and 54%. There are no difference between the first and after curves of the vertical hysteresis of 3D-LRB and no dependency of test speed because the dish springs take the vertical behaviors of 3D-LRB. (author). 8 refs., 38 tabs., 47 figs.

  4. 3D object-oriented image analysis in 3D geophysical modelling

    Fadel, I.; van der Meijde, M.; Kerle, N.;

    2015-01-01

    Non-uniqueness of satellite gravity interpretation has traditionally been reduced by using a priori information from seismic tomography models. This reduction in the non-uniqueness has been based on velocity-density conversion formulas or user interpretation of the 3D subsurface structures (objects......) based on the seismic tomography models and then forward modelling these objects. However, this form of object-based approach has been done without a standardized methodology on how to extract the subsurface structures from the 3D models. In this research, a 3D object-oriented image analysis (3D OOA......) approach was implemented to extract the 3D subsurface structures from geophysical data. The approach was applied on a 3D shear wave seismic tomography model of the central part of the East African Rift System. Subsequently, the extracted 3D objects from the tomography model were reconstructed in the 3D...

  5. The application of borehole seismic techniques in mine development at the millennium uranium deposit, Northern Saskatchewan, Canada

    Full text: The Millennium uranium deposit (indicated resource of 469 500 t at 4.53% U3O8) is located within the Athabasca basin of northern Saskatchewan, Canada. The deposit is hosted within steeply dipping Lower Proterozoic basement rocks, unconformably overlain by 500 m to 625 m of flat lying Athabasca Group sandstones. The deposit is associated with multiple graphitic faults, some of which are associated with post-Athabasca movement that has contributed to over 100 m of unconformity offset proximal to the deposit. The mineralization process has also resulted in intense hydrothermal alteration of the host rocks, and to a lesser extent the sandstone units located above the mineralization. All of these factors complicate the hydrological setting around the deposit, a factor that has to be accounted for in mine development. The pre-feasibility study for mine development commenced in 2007. In an attempt to minimize costs related to shaft sinking the proposed mine development was located to the east of the deposit, hanging wall to the mineralization. Two shaft pilot holes (CX-62 and CX-63) and an inclined exploration drill hole (CX-61) were completed in this area early in 2007. Single hole (Side-scan) seismic surveys were then completed in the shaft pilot holes and a multi-offset VSP (Vertical Seismic Profiling) survey in drill hole CX-61 in an attempt to: 1) map vertical to sub-vertical structure in the vicinity of the proposed mine shafts; 2) map unconformity offsets located in proximity of the proposed mine infrastructure and; 3) add to the geotechnical knowledge of the sandstone within the study area. The surveys successfully imaged subvertical structures and unconformity offset, adding insight into the hydrological controls within the study area. These surveys are now accepted by Cameco Corporation as a prerequisite for shaft sinking given the cost implications related to recent water inflow at minesites located within the Athabasca basin. (author)

  6. Comment on '3-D frequency-domain seismic wave modelling in heterogeneous, anisotropic media using a Gaussian quadrature grid approach' by Bing Zhou and S. A. Greenhalgh

    de Basabe, Jonás D.

    2011-08-01

    Zhou & Greenhalgh have recently presented an application of the Gaussian quadrature grid to seismic modelling in which the authors propose a meshing scheme that partitions the domain independently of the discontinuities in the media parameters. This comment aims to clarify the implications that this strategy has on the accuracy.

  7. 3D seismic travel time surveying - a comparison of the time-term method and tomography (an example from an archaeological site)

    Valenta, Jan; Dohnal, J.

    2007-01-01

    Roč. 63, č. 1 (2007), s. 46-58. ISSN 0926-9851 Institutional research plan: CEZ:AV0Z30460519 Keywords : shallow seismic * tomography * archaeology Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 0.938, year: 2007

  8. Fluid Substitution Modeling to Determine Sensitivity of 3D Vertical Seismic Profile Data to Injected CO­2­ at an active Carbon Capture, Utilization and Storage Project, Farnsworth field, TX.

    Haar, K. K.; Balch, R. S.

    2015-12-01

    The Southwest Regional Partnership on Carbon Sequestration monitors a CO2 capture, utilization and storage project at Farnsworth field, TX. The reservoir interval is a Morrowan age fluvial sand deposited in an incised valley. The sands are between 10 to 25m thick and located about 2800m below the surface. Primary oil recovery began in 1958 and by the late 1960's secondary recovery through waterflooding was underway. In 2009, Chaparral Energy began tertiary recovery using 100% anthropogenic CO2 sourced from an ethanol and a fertilizer plant. This constitutes carbon sequestration and fulfills the DOE's initiative to determine the best approach to permanent carbon storage. One purpose of the study is to understand CO­2 migration from injection wells. CO2­ plume spatial distribution for this project is analyzed with the use of time-lapse 3D vertical seismic profiles centered on CO2 injection wells. They monitor raypaths traveling in a single direction compared to surface seismic surveys with raypaths traveling in both directions. 3D VSP surveys can image up to 1.5km away from the well of interest, exceeding regulatory requirements for maximum plume extent by a factor of two. To optimize the timing of repeat VSP acquisition, the sensitivity of the 3D VSP surveys to CO2 injection was analyzed to determine at what injection volumes a seismic response to the injected CO­2 will be observable. Static geologic models were generated for pre-CO2 and post-CO2 reservoir states through construction of fine scale seismic based geologic models, which were then history matched via flow simulations. These generated static states of the model, where CO2­ replaces oil and brine in pore spaces, allow for generation of impedance volumes which when convolved with a representative wavelet generate synthetic seismic volumes used in the sensitivity analysis. Funding for the project is provided by DOE's National Energy Technology Laboratory (NETL) under Award No. DE-FC26-05NT42591.

  9. Borehole Data

    National Oceanic and Atmospheric Administration, Department of Commerce — Records of past temperature derived from boreholes drilled into the Earth crust. Parameter keywords describe what was measured in this data set. Additional summary...

  10. Crust and upper mantle in Dronning Maud Land/Antarctica retrieved from shear-wave splitting, receiver functions, seismic refraction and 3-D gravity modelling

    Bayer, Bettina; Müller, Christina; Geissler, Wolfram; Eaton, D. W.; Jokat, Wilfried; Eckstaller, Alfons

    2007-01-01

    The crust and upper mantle of Dronning Maud Land (DML), Antarctica, have been investigated using teleseismic data from broadband seismograph stations deployed at temporary and permanent locations and recordings from a seismic refraction experiment. For shear-wave splitting analyses the observed anisotropy can in most cases be related to major tectonic events that formed the geological features of the present-day Antarctic continent. We rule out an anisotropic contribution from recent asthenos...

  11. 3D Geological Model of Nihe ore deposit Constrained by Gravity and Magnetic Modeling

    Qi, Guang; Yan, Jiayong; Lv, Qingtan; Zhao, Jinhua

    2016-04-01

    We present a case study on using integrated geologic model in mineral exploration at depth. Nihe ore deposit in Anhui Province, is deep hidden ore deposit which was discovered in recent years, this finding is the major driving force of deep mineral exploration work in Luzong. Building 3D elaborate geological model has the important significance for prospecting to deep or surround in this area, and can help us better understand the metallogenic law and ore-controlling regularity. A 3D geological model, extending a depth from +200m to -1500m in Nihe ore deposit, has been compiled from surface geological map, cross-section, borehole logs and amounts of geological inference. And then the 3D geological models have been given physical property parameter for calculating the potential field. Modelling the potential response is proposed as means of evaluating the viability of the 3D geological models, and the evidence of making small changes to the uncertain parts of the original 3D geological models. It is expected that the final models not only reproduce supplied prior geological knowledge, but also explain the observed geophysical data. The workflow used to develop the 3D geologic model in this study includes the three major steps, as follows: (1) Determine the basic information of Model: Defining the 3D limits of the model area, the basic geological and structural unit, and the tectonic contact relations and the sedimentary sequences between these units. (2) 3D model construction: Firstly, a series of 2D geological cross sections over the model area are built by using all kinds of prior information, including surface geology, borehole data, seismic sections, and local geologists' knowledge and intuition. Lastly, we put these sections into a 3D environment according to their profile locations to build a 3D model by using geostatistics method. (3) 3D gravity and magnetic modeling: we calculate the potential field responses of the 3D model, and compare the predicted and

  12. 基于土-结构相互作用的高层建筑三维地震反应分析%3D Seismic Response of Tall Building Based on Soil-structure Interaction

    荣峰; 刘建伟; 王奎; 李彦峰; 李金艳

    2011-01-01

    基于刚性地基假定的工程结构抗震计算方法未充分考虑场地土对结构地震反应的影响.为验证土-结构相互作用对高层建筑三维地震反应的影响,本文针对某双塔高层建筑,分别建立了单塔上部结构、双塔整体结构以及土-结构相互作用共同工作三维有限元模型.研究对比了各结构体系的动力特性,并通过地震弹性时程反应分析法进行了结构体系三维地震反应分析与对比.结果表明,在考虑土-结构相互作用以后,结构体系频率、加速度反应峰值有所降低,结构位移增大,结构内力出现降低的趋势.因此,对于建立在深厚非基岩地基土上的较高或刚度较大的高层建筑,抗震分析时考虑土-结构相互作用的影响是必要的.%The calculation methods of structure seismic response based on the assumption of rigid foundation had not considered the influence of site soil sufficiently. In view of one double-tower tall building, the 3D finite element models of single-tower structure,double-tower structure, integrated soil-structure interaction system are established respectively in order to verify the iofluence of the 3D seismic response of tall building considering soil-structure interaction. The dynamical characteristics contrastive analysis is made, and 3D seismic response contrastive analysis through the method of elastic time-history response of systems is also made. The results show that in consideration of soil-structure interaction, the frequency and the peak value of acceleration response of structure are reduced,the displacement of structure is increased, and the internal force of structure are also reduced. So considering the influence of soil-structure interaction in seismic response analyzing is necessary for the tall or more rigid structures established on the thick soil ground foundation.

  13. Borehole-explosion and air-gun data acquired in the 2011 Salton Seismic Imaging Project (SSIP), southern California: description of the survey

    Rose, Elizabeth J.; Fuis, Gary S.; Stock, Joann M.; Hole, John A.; Kell, Annie M.; Kent, Graham; Driscoll, Neal W.; Goldman, Mark; Reusch, Angela M.; Han, Liang; Sickler, Robert R.; Catchings, Rufus D.; Rymer, Michael J.; Criley, Coyn J.; Scheirer, Daniel S.; Skinner, Steven M.; Slayday-Criley, Coye J.; Murphy, Janice M.; Jensen, Edward G.; McClearn, Robert; Ferguson, Alex J.; Butcher, Lesley A.; Gardner, Max A.; Emmons, Iain; Loughran, Caleb L.; Svitek, Joseph R.; Bastien, Patrick C.; Cotton, Joseph A.; Croker, David S.; Harding, Alistair J.; Babcock, Jeffrey M.; Harder, Steven H.; Rosa, Carla M.

    2013-01-01

    earthquake energy can travel through the sediments. All of these factors determine how hard the earth will shake during a major earthquake. If we can improve on our understanding of how and where earthquakes will occur, and how strong their resultant shaking will be, then buildings can be designed or retrofitted accordingly in order to resist damage and collapse, and emergency plans can be adequately prepared. In addition, SSIP will investigate the processes of rifting and magmatism in the Salton Trough in order to better understand this important plate-boundary region. The Salton Trough is a unique rift in that subsidence is accompanied by huge influxes of infilling sediment from the Colorado River. Volcanism that accompanies the subsidence here is muted by these influxes of sediment. The Salton Trough, in the central part of the Imperial Valley, is apparently made up of entirely new crust: young sediment in the upper crust and basaltic intrusive rocks in the mid-to-lower crust (Fuis and others, 1984). Similar to the ultrasound and computed tomography (CT) scans performed by the medical industry, seismic imaging is a collection of techniques that enable scientists to obtain a picture of what is underground. The petroleum industry routinely uses these techniques to search for oil and gas at relatively shallow depths; however, the scope of this project demanded that we image as much as 30 km into the Earth’s crust. This project generated and recorded seismic waves, similar to sound waves, which move downward into the Earth and are bent (refracted) or echoed (reflected) back to the surface. SSIP acquired data in a series of intersecting lines that cover key areas of the Salton Trough. The sources of sound waves were detonations (shots) in deep boreholes, designed to create energy equivalent to magnitude 1–2 earthquakes. The study region routinely experiences earthquakes of these magnitudes, but earthquakes are not located in such a way as to permit us to create the

  14. 3D Geological Model for "LUSI" - a Deep Geothermal System

    Sohrabi, Reza; Jansen, Gunnar; Mazzini, Adriano; Galvan, Boris; Miller, Stephen A.

    2016-04-01

    Geothermal applications require the correct simulation of flow and heat transport processes in porous media, and many of these media, like deep volcanic hydrothermal systems, host a certain degree of fracturing. This work aims to understand the heat and fluid transport within a new-born sedimentary hosted geothermal system, termed Lusi, that began erupting in 2006 in East Java, Indonesia. Our goal is to develop conceptual and numerical models capable of simulating multiphase flow within large-scale fractured reservoirs such as the Lusi region, with fractures of arbitrary size, orientation and shape. Additionally, these models can also address a number of other applications, including Enhanced Geothermal Systems (EGS), CO2 sequestration (Carbon Capture and Storage CCS), and nuclear waste isolation. Fractured systems are ubiquitous, with a wide-range of lengths and scales, making difficult the development of a general model that can easily handle this complexity. We are developing a flexible continuum approach with an efficient, accurate numerical simulator based on an appropriate 3D geological model representing the structure of the deep geothermal reservoir. Using previous studies, borehole information and seismic data obtained in the framework of the Lusi Lab project (ERC grant n°308126), we present here the first 3D geological model of Lusi. This model is calculated using implicit 3D potential field or multi-potential fields, depending on the geological context and complexity. This method is based on geological pile containing the geological history of the area and relationship between geological bodies allowing automatic computation of intersections and volume reconstruction. Based on the 3D geological model, we developed a new mesh algorithm to create hexahedral octree meshes to transfer the structural geological information for 3D numerical simulations to quantify Thermal-Hydraulic-Mechanical-Chemical (THMC) physical processes.

  15. Relationship between ridge segmentation and Moho transition zone structure from 3D multichannel seismic data collected over the fast-spreading East Pacific Rise at 9°50'N

    Aghaei, O.; Nedimovic, M. R.; Canales, J.; Carton, H. D.; Carbotte, S. M.; Mutter, J. C.

    2010-12-01

    We present stack and migrated stack volumes of a fast-spreading center produced from the high-resolution 3D multichannel seismic (MCS) data collected in summer of 2008 over the East Pacific Rise (EPR) at 9°50’N during cruise MGL0812. These volumes give us new insight into the 3D structure of the lower crust and Moho Transition Zone (MTZ) along and across the ridge axis, and how this structure relates to the ridge segmentation at the spreading axis. The area of 3D coverage is between 9°38’N and 9°58’N (~1000 km2) where the documented eruptions of 1990-91 and 2005-06 occurred. This high-resolution survey has a nominal bin size of 6.25 m in cross-axis direction and 37.5 m in along-axis direction. The prestack processing sequence applied to data includes 1D and 2D filtering to remove low-frequency cable noise, offset-dependent spherical divergence correction to compensate for geometrical spreading, surface-consistent amplitude correction to balance abnormally high/low shot and channel amplitudes, trace editing, velocity analysis, normal moveout (NMO), and CMP mute of stretched far offset arrivals. The poststack processing includes seafloor multiple mute to reduce migration noise and poststack time migration. We also will apply primary multiple removal and prestack time migration to the data and compare the results to the migrated stack volume. The poststack and prestack migrated volumes will then be used to detail Moho seismic signature variations and their relationship to ridge segmentation, crustal age, bathymetry, and magmatism. We anticipate that the results will also provide insight into the mantle upwelling pattern, which is actively debated for the study area.

  16. Exploration of the South-Eastern Alps lithosphere with 3D refraction seismics project Alp 2002 – data acquisition in Slovenia

    Andrej Gosar

    2003-06-01

    Full Text Available Using combined seismic refraction/wide-angle reflection method project Alp 2002 explored the contact zone between South-Eastern Alps, Dinarides and Pannonian basin. In a network of 12 profiles of 4100 km total length, which are spread over seven countries,1055 portable seismographs were deployed and 31 strong (300 kg explosions fired. In Slovenia 127 seismographs were deployed along five profiles totalling 575 km and two explosions fired near Vojnik and Gradin. The collected data will allow construction of athree-dimensional model of the lithosphere and will contribute to the understanding of the tectonics and geodynamics at the junction of European, Adriatic and Tisza plates.

  17. 3D seismic structure of the Zhenbei-Huangyan seamount chain in the East sub-basin of the South China Sea and its mechanism of formation

    Zhao, M.; Wang, J.; Qiu, X.; Sibuet, J. C.; He, E.; Zhang, J.

    2015-12-01

    The post-spreading volcanic ridge (PSVR) is oriented approximately E-W in its western part called the Zhenbei-Huangyan seamount chain. Where is the extinct spreading ridge (ESR) of the East Sub-basin located? beneath the PSVR (Li et al., 2014)? Or intersecting with the PSVR by N055° orientation (Sibuet et al., submitted)? A three-dimensional Ocean Bottom Seismometer (OBS) survey covered both the central extinct spreading ridge and the Zhenbei-Huangyan seamount chain, the IODP Site U1431 (Li et al., 2014) being located just north of the chain. The results of this experiment will provide the essential information to understand the emplacement of the PSVR within the previously formed oceanic crust. The comprehensive seismic record sections of 39 OBSs are of high quality and show clear and reliable P-wave seismic phases, such as Pg, Pn and PmP. These seismic arrivals provide strong constrains for modeling the detailed three-dimensional velocity structure. We will show that the crust is oceanic on each side of the Zhenbei-Huangyan seamount chain, where is the location of the ESR and what is the genetic relationship between the magma chambers and the overlying Zhenbei-Huangyan seamount chain. We suggest that the large thickness of the upper crust is possibly due to volcanic extrusions and the thickened lower crust to magmatic underplating. Combining previous geochemical study of PSVR outcropping samples, the formation mechanism of the seamount chain might be explained by a buoyancy decompression melting mechanism (Castillo et al., 2010). This research was granted by the Natural Science Foundation of China (91028002, 91428204, 41176053). ReferencesSibuet J.-C., Yeh Y.-C. and Lee C.-S., 2015 submitted. Geodynamics of the South China Sea: A review with emphasis on solved and unsolved questions. Tectonophysics. Li, C. F., et al. 2014. Ages and magnetic structures of the South China Sea constrained by deep tow magnetic surveys and IODP Expedition 349. Geochemistry

  18. 3D video

    Lucas, Laurent; Loscos, Céline

    2013-01-01

    While 3D vision has existed for many years, the use of 3D cameras and video-based modeling by the film industry has induced an explosion of interest for 3D acquisition technology, 3D content and 3D displays. As such, 3D video has become one of the new technology trends of this century.The chapters in this book cover a large spectrum of areas connected to 3D video, which are presented both theoretically and technologically, while taking into account both physiological and perceptual aspects. Stepping away from traditional 3D vision, the authors, all currently involved in these areas, provide th

  19. 3D Animation Essentials

    Beane, Andy

    2012-01-01

    The essential fundamentals of 3D animation for aspiring 3D artists 3D is everywhere--video games, movie and television special effects, mobile devices, etc. Many aspiring artists and animators have grown up with 3D and computers, and naturally gravitate to this field as their area of interest. Bringing a blend of studio and classroom experience to offer you thorough coverage of the 3D animation industry, this must-have book shows you what it takes to create compelling and realistic 3D imagery. Serves as the first step to understanding the language of 3D and computer graphics (CG)Covers 3D anim

  20. A critical appraisal of asymptotic 3D-to-2D data transformation filters and the potential of complex frequency 2.5-D modeling in seismic full waveform inversion

    Auer, L.; Greenhalgh, S. A.; Maurer, H. R.; Marelli, S.; Nuber, A.

    2012-04-01

    Seismic full waveform inversion is often based on forward modeling in the computationally attractive 2-D domain. Any solution of the 2-D cartesian wave equation inherently carries the implicit assumption of a line source extended in the out-of-plane medium invariant direction. This implies that the source energy in homogeneous media spreads over the surface of an approximately expanding cylinder, such that the wavefield amplitudes (at least in the far field) scale inversely with the square-root of distance. However, realistic point sources like explosives or airguns, fired in a 3-D medium, generate amplitudes that decay inversely with the first power of distance, since the wavefield expands quasi-spherically in all three dimensions. Usually, practitioners correct for this amplitude difference and the associated phase shift of π/4 by transforming the recorded 3-D field data to the approximate 2-D situation by using simplistic, asymptotic filter algorithms. Such filters operate on a square root of time-sample convolutional basis and implicitly assume straight ray paths and a constant velocity medium. The unsubstantiated usage of these asymptotic filters is in contradiction to their well known limitations. In this study, we present an extensive quantitative appraisal of 3D-to-2D data transformation procedures. Our analysis relies on a simple numerical modeling study, based on propagating 3-D and 2-D wavefields through 2-D media and comparing the true 2-D and the filtered 3-D synthetic data. It is shown that the filtering errors are moderate in purely acoustic situations but become substantial in complex media when arrivals overlap each other or ray paths deviate strongly from straight lines. Normalized root-mean-square deviations up to 5% and maximum relative time domain errors of up to 40% were found in high contrast media, when full elastic treatment was considered. In order to examine if this error translates into a deficient model reconstruction in full waveform

  1. Regional geothermal 3D modelling in Denmark

    Poulsen, S. E.; Balling, N.; Bording, T. S.; Nielsen, S. B.

    2012-04-01

    In the pursuit of sustainable and low carbon emission energy sources, increased global attention has been given to the exploration and exploitation of geothermal resources within recent decades. In 2009 a national multi-disciplinary geothermal research project was established. As a significant part of this project, 3D temperature modelling is to be carried out, with special emphasis on temperatures of potential geothermal reservoirs in the Danish area. The Danish subsurface encompasses low enthalpy geothermal reservoirs of mainly Triassic and Jurassic age. Geothermal plants at Amager (Copenhagen) and Thisted (Northern Jutland) have the capacity of supplying the district heating network with up to 14 MW and 7 MW, respectively, by withdrawing warm pore water from the Gassum (Lower Jurassic/Upper Triassic) and Bunter (Lower Triassic) sandstone reservoirs, respectively. Explorative studies of the subsurface temperature regime typically are based on a combination of observations and modelling. In this study, the open-source groundwater modelling code MODFLOW is modified to simulate the subsurface temperature distribution in three dimensions by taking advantage of the mathematical similarity between saturated groundwater flow (Darcy flow) and heat conduction. A numerical model of the subsurface geology in Denmark is built and parameterized from lithological information derived from joint interpretation of seismic surveys and borehole information. Boundary conditions are constructed from knowledge about the heat flow from the Earth's interior and the shallow ground temperature. Matrix thermal conductivities have been estimated from analysis of high-resolution temperature logs measured in deep wells and porosity-depth relations are included using interpreted main lithologies. The model takes into account the dependency of temperature and pressure on thermal conductivity. Moreover, a transient model based correction of the paleoclimatic thermal disturbance caused by the

  2. 3-D Shear Wave Velocity Model of Mexico and South US: Bridging Seismic Networks with Ambient Noise Cross-Correlations (C1) and Correlation of Coda of Correlations (C3).

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba Montiel, Francisco; Iglesias, Arturo

    2016-07-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group travel times are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  3. 3-D shear wave velocity model of Mexico and South US: bridging seismic networks with ambient noise cross-correlations (C1) and correlation of coda of correlations (C3)

    Spica, Zack; Perton, Mathieu; Calò, Marco; Legrand, Denis; Córdoba-Montiel, Francisco; Iglesias, Arturo

    2016-09-01

    This work presents an innovative strategy to enhance the resolution of surface wave tomography obtained from ambient noise cross-correlation (C1) by bridging asynchronous seismic networks through the correlation of coda of correlations (C3). Rayleigh wave group dispersion curves show consistent results between synchronous and asynchronous stations. Rayleigh wave group traveltimes are inverted to construct velocity-period maps with unprecedented resolution for a region covering Mexico and the southern United States. The resulting period maps are then used to regionalize dispersion curves in order to obtain local 1-D shear velocity models (VS) of the crust and uppermost mantle in every cell of a grid of 0.4°. The 1-D structures are obtained by iteratively adding layers until reaching a given misfit, and a global tomography model is considered as an input for depths below 150 km. Finally, a high-resolution 3-D VS model is obtained from these inversions. The major structures observed in the 3-D model are in agreement with the tectonic-geodynamic features and with previous regional and local studies. It also offers new insights to understand the present and past tectonic evolution of the region.

  4. Effect of a low-velocity sedimentary cover on the 3-D velocity models derived from inversion of local arrival times. An example from the New Madrid seismic zone.

    Pujol, J. M.; Chiu, J. M.

    2014-12-01

    When applying seismic tomography to local arrival times from an area with a low-velocity sedimentary cover, the effect of the sediments on travel times should be taken into account. If that is not done, the resulting velocity model(s) cannot be assumed to be correct. This fairly obvious statement has been challenged recently by Powell et al. (JGR, 2010), who claimed that the sediments that cover the New Madrid seismic zone (NMSZ, central United States) can be ignored. This claim is examined here and shown to be incorrect. The NMSZ is covered by low-velocity, poorly consolidated sediments (Vp=1.8 km/s, Vs=3), which are underlain by Paleozoic rocks of much higher velocity. In the central NMSZ the sediment thickness varies between about 0.1 and 0.7 km. The JHD analysis of the data collected in that area by a portable network (PANDA) showed that the P- and S-wave station corrections spanned large ranges (0.35 and 0.63 s, respectively, Pujol et al., Eng. Geol., 1997). This study also showed that a Vp/Vs of 3 for the sediments would be too high if the lateral velocity variations were confined to the sedimentary cover. Here we generate synthetic traveltimes for a model with a sedimentary cover having variable depth (as determined from boreholes) underlain by the high-velocity layers in the 1-D model used for the JHD analysis. The synthetic data were generated for the station and event distributions corresponding to the Panda data. The tomographic inversion of the synthetic times produces spurious anomalies in Vp, Vs, and Vp/Vs, from the surface to a depth of 10 km. In addition, the events are mislocated in depth, with errors between 0 and 1 km for most of them. These results should dispel the notion that the effect of the unconsolidated sediments can be ignored. On the other hand, the inversion of the actual Panda data results in velocity anomalies similar to the synthetic anomalies, although larger, which is consistent with the conclusions of Pujol et al. (1997

  5. EUROPEANA AND 3D

    D. Pletinckx

    2012-09-01

    Full Text Available The current 3D hype creates a lot of interest in 3D. People go to 3D movies, but are we ready to use 3D in our homes, in our offices, in our communication? Are we ready to deliver real 3D to a general public and use interactive 3D in a meaningful way to enjoy, learn, communicate? The CARARE project is realising this for the moment in the domain of monuments and archaeology, so that real 3D of archaeological sites and European monuments will be available to the general public by 2012. There are several aspects to this endeavour. First of all is the technical aspect of flawlessly delivering 3D content over all platforms and operating systems, without installing software. We have currently a working solution in PDF, but HTML5 will probably be the future. Secondly, there is still little knowledge on how to create 3D learning objects, 3D tourist information or 3D scholarly communication. We are still in a prototype phase when it comes to integrate 3D objects in physical or virtual museums. Nevertheless, Europeana has a tremendous potential as a multi-facetted virtual museum. Finally, 3D has a large potential to act as a hub of information, linking to related 2D imagery, texts, video, sound. We describe how to create such rich, explorable 3D objects that can be used intuitively by the generic Europeana user and what metadata is needed to support the semantic linking.

  6. 3D Lithospheric Structure in an Arc-Continent Collisional Setting: Results from the EarthScope IDOR Passive Seismic Receiver Functions

    Stanciu, A. C.; Russo, R. M.; Mocanu, V. I.; Foster, D. A.; Bremner, P. M.; Torpey, M. E.; Hongsresawat, S.; VanDecar, J. C.; Hole, J. A.; Tikoff, B.

    2014-12-01

    We present new images of lithospheric structure obtained from P-to-S receiver functions at 86 broadband seismic stations we deployed as part of the EarthScope IDOR experiment. The high-quality data of the IDOR survey allowed us to image in detail the crustal thickness, and the structure of the lithospheric mantle beneath the Blue Mountains accreted terranes and the Paleozoic margin of North America. At the surface, the ~110 Ma suture between the arc terranes and the North American Craton is marked by the dextral transpressional system of the Western Idaho Shear Zone (WISZ), which closely follows the Sr 0.706 isopleth. Long-lived magmatism (108 - 50 Ma) of the Idaho Batholith occurred during and after the WISZ deformation. We constructed more than 7000 P-to-S teleseismic receiver functions using iterative time domain deconvolution, and we used H-k grid search, inversion, and common conversion point stacking (CCP) to image the lithospheric structure. Moho depths vary from 35-40 km beneath the Blue Mountain terranes and the extended regions of central Idaho, and shallow to ~30 km in the central part of the IDOR network. We see a clear break in the continuity of the Moho across the WISZ, with depths increasing from 30 to 40 km east of the WISZ. We also see a strong mid-crustal converting interface at 15-20 km depth beneath the Idaho Batholith on the east side of the WISZ. To the east, beneath the Lost River Range and Pahsimeroi valley, we see an offset in Moho depth possibly related to Basin-and-Range extension. A strong shallow contrast in crustal velocities beneath the West Snake River Plain is probably due to Columbia River Basalts and sedimentary cover. We observe a horizontal, continuous positive amplitude phase at ~90 km across the entire network that we interpret as the Mid-Lithospheric Discontinuity. A second positive amplitude phase varies from ~120 km beneath the accreted terranes to ~140 km beneath the western margin of the North American Craton. The

  7. Solid works 3D

    This book explains modeling of solid works 3D and application of 3D CAD/CAM. The contents of this book are outline of modeling such as CAD and 2D and 3D, solid works composition, method of sketch, writing measurement fixing, selecting projection, choosing condition of restriction, practice of sketch, making parts, reforming parts, modeling 3D, revising 3D modeling, using pattern function, modeling necessaries, assembling, floor plan, 3D modeling method, practice floor plans for industrial engineer data aided manufacturing, processing of CAD/CAM interface.

  8. Structure and Stratigraphy of the Rift Basins in the Northern Gulf of California: Results from Analysis of Seismic Reflection and Borehole Data.

    Martín, A.; González, M.; Helenes, J.; García, J.; Aragón, M.; Carreño, A.

    2008-12-01

    The northern Gulf of California contains two parallel, north-south trending rift basin systems separated by a basement-high. The interpretation of several exploration wells, and ~4500 km of seismic reflection data from PEMEX (Mexican national oil company) indicate that the tectonically active basins to the west (Wagner- Consag and Upper Delfin basins) may have initiated synchronously with the now abandoned Tiburón- Tepoca-Altar basins to the east in the Sonora margin. In both basin systems the lower sequence (A) is marine mudstone-siltstone, has parallel reflectors and a largely uniform thickness that reaches up to1.5 km, and gradually pinches out toward the lateral margins. This suggests that the unit was deposited prior to their segmentation by transtensional faulting. Marine microfossils from borehole samples from sequence A in the Tiburón and Consag basins indicates middle Miocene (>11.2 Ma) proto-Gulf conditions. Sequence B conformably overlies sequence A, and is characterized by up to 2 km growth strata with a fanning geometry that show a clear genetic relationship to the major transtensional faults that control the segmentation of the two basin systems. Sequence C in the Tiburón and Tepoca basins is comparatively thin (<800 m) and includes several unconformities, but is much less affected by faulting. In contrast, sequence C in the active Wagner, Consag and Upper Delfin basin is a much thicker (up to 2 km) growth sequence with abundant volcanic intrusions. Marked variations in sequence C in the different basin systems clearly demonstrate a major westward shift of deformation and subsidence at this time. The modern depocenter in Wagner-Consag basins is controlled by the Consag and Wagner faults, which trend parallel to the north ~20 km apart, and show opposite normal offset. These two faults merge at an oblique angle (70°-50°, respectively) into the Cerro Prieto transform fault to the north and likely accommodate an important amount of dextral shear. To

  9. Open 3D Projects

    Felician ALECU

    2010-01-01

    Full Text Available Many professionals and 3D artists consider Blender as being the best open source solution for 3D computer graphics. The main features are related to modeling, rendering, shading, imaging, compositing, animation, physics and particles and realtime 3D/game creation.

  10. Seismic Prediction While Drilling (SPWD: Looking Ahead of the Drill Bit by Application of Phased Array Technology

    Marco Groh

    2010-04-01

    Full Text Available Geophysical exploration is indispensable for planning deep drilling. Usually 2D- or 3D-seismics investigations are applied and, depending on the resulting geologic model for the underground, the drill site and drilling path are determined. In recent years the focus of exploration has shifted towards small-scale geological structures such as local layers and faults. Depending on the source frequencies and the target depth, 2D- or 3D-seismics from surface cannot always resolve such structures in particular at larger depths. In general, signal frequencies of about 30–70 Hz are typical for surface seismic methods. The deeper and smaller the sought-after structures are, the worse will be the resolution. Therefore, borehole seismic measurements like Vertical Seismic Profile (VSP or Seismic While Drilling (SWD have been developed (Fig. 1. For the VSP method geophones are normally integrated in the borehole, while the seismicsource generates seismic waves at the surface. The SWD method uses the drill bit as the seismic source. Hence, the quality of the seismic signals is highly dependent on the drilled rock and the type of drill bit, but even well-suited rock conditions and adequate drilling may not provide sufficient data quality.

  11. 3d-3d correspondence revisited

    Chung, Hee-Joong; Dimofte, Tudor; Gukov, Sergei; Sułkowski, Piotr

    2016-04-01

    In fivebrane compactifications on 3-manifolds, we point out the importance of all flat connections in the proper definition of the effective 3d {N}=2 theory. The Lagrangians of some theories with the desired properties can be constructed with the help of homological knot invariants that categorify colored Jones polynomials. Higgsing the full 3d theories constructed this way recovers theories found previously by Dimofte-Gaiotto-Gukov. We also consider the cutting and gluing of 3-manifolds along smooth boundaries and the role played by all flat connections in this operation.

  12. IZDELAVA TISKALNIKA 3D

    Brdnik, Lovro

    2015-01-01

    Diplomsko delo analizira trenutno stanje 3D tiskalnikov na trgu. Prikazan je razvoj in principi delovanja 3D tiskalnikov. Predstavljeni so tipi 3D tiskalnikov, njihove prednosti in slabosti. Podrobneje je predstavljena zgradba in delovanje koračnih motorjev. Opravljene so meritve koračnih motorjev. Opisana je programska oprema za rokovanje s 3D tiskalniki in komponente, ki jih potrebujemo za izdelavo. Diploma se oklepa vprašanja, ali je izdelava 3D tiskalnika bolj ekonomična kot pa naložba v ...

  13. LOTT RANCH 3D PROJECT

    The Lott Ranch 3D seismic prospect located in Garza County, Texas is a project initiated in September of 1991 by the J.M. Huber Corp., a petroleum exploration and production company. By today's standards the 126 square mile project does not seem monumental, however at the time it was conceived it was the most intensive land 3D project ever attempted. Acquisition began in September of 1991 utilizing GEO-SEISMIC, INC., a seismic data contractor. The field parameters were selected by J.M. Huber, and were of a radical design. The recording instruments used were GeoCor IV amplifiers designed by Geosystems Inc., which record the data in signed bit format. It would not have been practical, if not impossible, to have processed the entire raw volume with the tools available at that time. The end result was a dataset that was thought to have little utility due to difficulties in processing the field data. In 1997, Yates Energy Corp. located in Roswell, New Mexico, formed a partnership to further develop the project. Through discussions and meetings with Pinnacle Seismic, it was determined that the original Lott Ranch 3D volume could be vastly improved upon reprocessing. Pinnacle Seismic had shown the viability of improving field-summed signed bit data on smaller 2D and 3D projects. Yates contracted Pinnacle Seismic Ltd. to perform the reprocessing. This project was initiated with high resolution being a priority. Much of the potential resolution was lost through the initial summing of the field data. Modern computers that are now being utilized have tremendous speed and storage capacities that were cost prohibitive when this data was initially processed. Software updates and capabilities offer a variety of quality control and statics resolution, which are pertinent to the Lott Ranch project. The reprocessing effort was very successful. The resulting processed data-set was then interpreted using modern PC-based interpretation and mapping software. Production data, log data

  14. 3D and Education

    Meulien Ohlmann, Odile

    2013-02-01

    Today the industry offers a chain of 3D products. Learning to "read" and to "create in 3D" becomes an issue of education of primary importance. 25 years professional experience in France, the United States and Germany, Odile Meulien set up a personal method of initiation to 3D creation that entails the spatial/temporal experience of the holographic visual. She will present some different tools and techniques used for this learning, their advantages and disadvantages, programs and issues of educational policies, constraints and expectations related to the development of new techniques for 3D imaging. Although the creation of display holograms is very much reduced compared to the creation of the 90ies, the holographic concept is spreading in all scientific, social, and artistic activities of our present time. She will also raise many questions: What means 3D? Is it communication? Is it perception? How the seeing and none seeing is interferes? What else has to be taken in consideration to communicate in 3D? How to handle the non visible relations of moving objects with subjects? Does this transform our model of exchange with others? What kind of interaction this has with our everyday life? Then come more practical questions: How to learn creating 3D visualization, to learn 3D grammar, 3D language, 3D thinking? What for? At what level? In which matter? for whom?

  15. Continuous recording of seismic signals in Alpine permafrost

    Hausmann, H.; Krainer, K.; Staudinger, M.; Brückl, E.

    2009-04-01

    Over the past years various geophysical methods were applied to study the internal structure and the temporal variation of permafrost whereof seismic is of importance. For most seismic investigations in Alpine permafrost 24-channel equipment in combination with long data and trigger cables is used. Due to the harsh environment source and geophone layouts are often limited to 2D profiles. With prospect for future 3D-layouts we introduce an alternative of seismic equipment that can be used for several applications in Alpine permafrost. This study is focussed on controlled and natural source seismic experiments in Alpine permafrost using continuous data recording. With recent data from an ongoing project ("Permafrost in Austria") we will highlight the potential of the used seismic equipment for three applications: (a) seismic permafrost mapping of unconsolidated sediments, (b) seismic tomography in rock mass, and (c) passive seismic monitoring of rock falls. Single recording units (REFTEK 130, 6 channels) are used to continuously record the waveforms of both the seismic signals and a trigger signal. The combination of a small number of recording units with different types of geophones or a trigger allow numerous applications in Alpine permafrost with regard to a high efficiency and flexible seismic layouts (2D, 3D, 4D). The efficiency of the light and robust seismic equipment is achieved by the simple acquisition and the flexible and fast deployment of the (omni-directional) geophones. Further advantages are short (data and trigger) cables and the prevention of trigger errors. The processing of the data is aided by 'Seismon' which is an open source software project based on Matlab® and MySQL (see SM1.0). For active-source experiments automatic stacking of the seismic signals is implemented. For passive data a program for automatic detection of events (e.g. rock falls) is available which allows event localization. In summer 2008 the seismic equipment was used for the

  16. 3D virtuel udstilling

    Tournay, Bruno; Rüdiger, Bjarne

    2006-01-01

    3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s.......3d digital model af Arkitektskolens gård med virtuel udstilling af afgangsprojekter fra afgangen sommer 2006. 10 s....

  17. Underwater 3D filming

    Roberto Rinaldi

    2014-12-01

    Full Text Available After an experimental phase of many years, 3D filming is now effective and successful. Improvements are still possible, but the film industry achieved memorable success on 3D movie’s box offices due to the overall quality of its products. Special environments such as space (“Gravity” and the underwater realm look perfect to be reproduced in 3D. “Filming in space” was possible in “Gravity” using special effects and computer graphic. The underwater realm is still difficult to be handled. Underwater filming in 3D was not that easy and effective as filming in 2D, since not long ago. After almost 3 years of research, a French, Austrian and Italian team realized a perfect tool to film underwater, in 3D, without any constrains. This allows filmmakers to bring the audience deep inside an environment where they most probably will never have the chance to be.

  18. Visualization of 3D Geological Models on Google Earth

    Choi, Y.; Um, J.; Park, M.

    2013-05-01

    Google Earth combines satellite imagery, aerial photography, thematic maps and various data sets to make a three-dimensional (3D) interactive image of the world. Currently, Google Earth is a popular visualization tool in a variety of fields and plays an increasingly important role not only for private users in daily life, but also for scientists, practitioners, policymakers and stakeholders in research and application. In this study, a method to visualize 3D geological models on Google Earth is presented. COLLAborative Design Activity (COLLADA, an open standard XML schema for establishing interactive 3D applications) was used to represent different 3D geological models such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes (a set of triangles connected by their common edges or corners). In addition, we designed Keyhole Markup Language (KML, the XML-based scripting language of Google Earth) codes to import the COLLADA files into the 3D render window of Google Earth. The method was applied to the Grosmont formation in Alberta, Canada. The application showed that the combination of COLLADA and KML enables Google Earth to effectively visualize 3D geological structures and properties.; Visualization of the (a) boreholes, (b) fence sections, (c) 3D volume model and (d) 3D grid model of Grossmont formation on Google Earth

  19. 3D Gravity Inversion using Tikhonov Regularization

    Toushmalani Reza

    2015-08-01

    Full Text Available Subsalt exploration for oil and gas is attractive in regions where 3D seismic depth-migration to recover the geometry of a salt base is difficult. Additional information to reduce the ambiguity in seismic images would be beneficial. Gravity data often serve these purposes in the petroleum industry. In this paper, the authors present an algorithm for a gravity inversion based on Tikhonov regularization and an automatically regularized solution process. They examined the 3D Euler deconvolution to extract the best anomaly source depth as a priori information to invert the gravity data and provided a synthetic example. Finally, they applied the gravity inversion to recently obtained gravity data from the Bandar Charak (Hormozgan, Iran to identify its subsurface density structure. Their model showed the 3D shape of salt dome in this region

  20. An isostatic study of the Karoo basin and underlying lithosphere in 3-D

    Scheiber-Enslin, Stephanie E.; Ebbing, Jörg; Webb, Susan J.

    2016-08-01

    A 3-D density model of the crust and upper mantle beneath the Karoo basin is presented here. The model is constrained using potential field, borehole and seismic data. Uplift of the basin by the end of the Cretaceous has resulted in an unusually high plateau (>1000 m) covering a large portion of South Africa. Isostatic studies show the topography is largely compensated by changes in Moho depths (˜35 km on-craton and >45 km off-craton) and changes in lithospheric mantle densities between the Kaapvaal Craton and surrounding regions (˜50 kg m-3 increase from on- to off-craton). This density contrast is determined by inverted satellite gravity and gravity gradient data. The highest topography along the edge of the plateau (>1200 m) and a strong Bouguer gravity low over Lesotho, however, can only be explained by a buoyant asthenosphere with a density decrease of around 40 kg m-3.

  1. Application of 3D Seismic Prospecting Technology in Songxinzhuang Minefield%三维地震勘探技术在宋新庄井田中的应用

    于谦

    2011-01-01

    以宋新庄井田三维地震勘探为例,介绍了该区主要地震反射波组与标志层位的对应关系,并通过对T3、T10、T18波的研究查明了勘探区构造形态:除了对甜水堡背斜形态及位置更明确外,还新发现汪水塘向斜及9条新断层,其中DFS逆断层及西移的金家渠子西侧逆断层控制了该井田边界.通过对煤层隐伏露头的解释及钻孔验证,证实部分煤层露头向东南平移200~500m,扩大了煤层赋存范围.另外强反射波组TN、TE表现,确定了新生界古松散层内部地层的界限及底界与下伏地层的不整合关系,该区新生界底界面总的变化趋势为西部高、东部低.%To take the 3D seismic prospecting in the Songxinzhuang minefield as an example.introduced correspondence between main seismic reflection wave group and marker horizon,and through study work over T3,T10 and T18 waves has found out structural forms in the prospecting area.Other than form and location definitudes of the Tianshuipu anticline,also newly found the Wangshuitang syncline and 9 faults,in which,the DF,reverse fault and westward moved Jinjiaquzi west reverse fault have controlled the boundary of the minefield.Based on interpretation of coal seam buried outcrop and drilling verification.demonstrated that part of coal seam outcrops have translated southeastward 200~500m,thus extended coal seam hosting scope.In addition,expressions of strong reflection wave groups TN and TE have confirmed Cenozoic loose bed internal demarcation lines and unconformable relatio between its bottom and underlying strata.Overall variation trend of Cenozoic bottom boundary is high in west.low in east.

  2. Blender 3D cookbook

    Valenza, Enrico

    2015-01-01

    This book is aimed at the professionals that already have good 3D CGI experience with commercial packages and have now decided to try the open source Blender and want to experiment with something more complex than the average tutorials on the web. However, it's also aimed at the intermediate Blender users who simply want to go some steps further.It's taken for granted that you already know how to move inside the Blender interface, that you already have 3D modeling knowledge, and also that of basic 3D modeling and rendering concepts, for example, edge-loops, n-gons, or samples. In any case, it'

  3. Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland

    Bethmann, Falko

    2012-08-01

    We investigate attenuation (Q−1) of sediments of 2.5–3.5km thickness underneath the city of Basel, Switzerland. We use recordings of 195 induced events that were obtained during and after the stimulation of a reservoir for a Deep Heat Mining Project in 2006 and 2007. The data set is ideally suited to estimate Q as all events are confined to a small source volume and were recorded by a dense surface network as well as six borehole sensors at various depths. The deepest borehole sensor is positioned at a depth of 2.7km inside the crystalline basement at a mean hypocentral distance of 1.8km. This allows us to measure Q for frequencies between 10 and 130 Hz. We apply two different methods to estimate Q. First, we use a standard spectral ratio technique to obtain Q, and as a second measure we estimate Q in the time domain, by convolving signals recorded by the deepest sensor with a Q operator and then comparing the convolved signals to recordings at the shallower stations. Both methods deliver comparable values for Q. We also observe similar attenuation for P- and S- waves (QP∼QS). As expected, Q increases with depth, but with values around 30–50, it is low even for the consolidated Permian and Mesozoic sediments between 500 and 2700 m.

  4. 3D Digital Modelling

    Hundebøl, Jesper

    wave of new building information modelling tools demands further investigation, not least because of industry representatives' somewhat coarse parlance: Now the word is spreading -3D digital modelling is nothing less than a revolution, a shift of paradigm, a new alphabet... Research qeustions. Based...... on empirical probes (interviews, observations, written inscriptions) within the Danish construction industry this paper explores the organizational and managerial dynamics of 3D Digital Modelling. The paper intends to - Illustrate how the network of (non-)human actors engaged in the promotion (and arrest) of 3......D Modelling (in Denmark) stabilizes - Examine how 3D Modelling manifests itself in the early design phases of a construction project with a view to discuss the effects hereof for i.a. the management of the building process. Structure. The paper introduces a few, basic methodological concepts...

  5. Visualization of 3D Geological Data using COLLADA and KML

    Choi, Yosoon; Um, Jeong-Gi; Park, Myong-Ho

    2013-04-01

    This study presents a method to visualize 3D geological data using COLLAborative Design Activity(COLLADA, an open standard XML schema for establishing interactive 3D applications) and Keyhole Markup Language(KML, the XML-based scripting language of Google Earth).We used COLLADA files to represent different 3D geological data such as borehole, fence section, surface-based 3D volume and 3D grid by triangle meshes(a set of triangles connected by their common edges or corners). The COLLADA files were imported into the 3D render window of Google Earth using KML codes. An application to the Grosmont formation in Alberta, Canada showed that the combination of COLLADA and KML enables Google Earth to visualize 3D geological structures and properties.

  6. Professional Papervision3D

    Lively, Michael

    2010-01-01

    Professional Papervision3D describes how Papervision3D works and how real world applications are built, with a clear look at essential topics such as building websites and games, creating virtual tours, and Adobe's Flash 10. Readers learn important techniques through hands-on applications, and build on those skills as the book progresses. The companion website contains all code examples, video step-by-step explanations, and a collada repository.

  7. 3D characterization of the Astor Pass geothermal system, Nevada

    Mayhew, Brett [NBMG; Faulds, James E

    2013-10-19

    The Astor Pass geothermal system resides in the northwestern part of the Pyramid Lake Paiute Reservation, on the margins of the Basin and Range and Walker Lane tectonic provinces in northwestern Nevada. Seismic reflection interpretation, detailed analysis of well cuttings, stress field analysis, and construction of a 3D geologic model have been used in the characterization of the stratigraphic and structural framework of the geothermal area. The area is primarily comprised of middle Miocene Pyramid sequence volcanic and sedimentary rocks, nonconformably overlying Mesozoic metamorphic and granitic rocks. Wells drilled at Astor Pass show a ~1 km thick section of highly transmissive Miocene volcanic reservoir with temperatures of ~95°C. Seismic reflection interpretation confirms a high fault density in the geothermal area, with many possible fluid pathways penetrating into the relatively impermeable Mesozoic basement. Stress field analysis using borehole breakout data reveals a complex transtensional faulting regime with a regionally consistent west-northwest-trending least principal stress direction. Considering possible strike-slip and normal stress regimes, the stress data were utilized in a slip and dilation tendency analysis of the fault model, which suggests two promising fault areas controlling upwelling geothermal fluids. Both of these fault intersection areas show positive attributes for controlling geothermal fluids, but hydrologic tests show the ~1 km thick volcanic section is highly transmissive. Thus, focused upwellings along discrete fault conduits may be confined to the Mesozoic basement before fluids diffuse into the Miocene volcanic reservoir above. This large diffuse reservoir in the faulted Miocene volcanic rocks is capable of sustaining high pump rates. Understanding this type of system may be helpful in examining large, permeable reservoirs in deep sedimentary basins of the eastern Basin and Range and the highly fractured volcanic geothermal

  8. Geopressure and Trap Integrity Predictions from 3-D Seismic Data: Case Study of the Greater Ughelli Depobelt, Niger Delta Pressions de pores et prévisions de l’intégrité des couvertures à partir de données sismiques 3D : le cas du grand sous-bassin d’Ughelli, Delta du Niger

    Opara A.I.

    2012-05-01

    Full Text Available The deep drilling campaign in the Niger Delta has demonstrated the need for a detailed geopressure and trap integrity (drilling margin analysis as an integral and required step in prospect appraisal. Pre-drill pore pressure prediction from 3-D seismic data was carried out in the Greater Ughelli depobelt, Niger Delta basin to predict subsurface pressure regimes and further applied in the determination of hydrocarbon column height, reservoir continuity, fault seal and trap integrity. Results revealed that geopressured sedimentary formations are common within the more prolific deeper hydrocarbon reserves in the Niger Delta basin. The depth to top of mild geopressure (0.60 psi/ft ranges from about 10 000 ftss to over 30 000 ftss. The distribution of geopressures shows a well defined trend with depth to top of geopressures increasing towards the central part of the basin. This variation in the depth of top of geopressures in the area is believed to be related to faulting and shale diapirism, with top of geopressures becoming shallow with shale diapirism and deep with sedimentation. Post-depositional faulting is believed to have controlled the configuration of the geopressure surface and has played later roles in modifying the present day depth to top of geopressures. In general, geopressure in this area is often associated with simple rollover structures bounded by growth faults, especially at the hanging walls, while hydrostatic pressures were observed in areas with k-faults and collapsed crested structures. Les campagnes de forages profonds dans le delta du Niger ont démontré la nécessité d’une analyse détaillée des surpressions et de l’intégrité des structures pour évaluer correctement les prospects. La prédiction des pressions interstitielles a pu être réalisée ici avant forage à partir de données sismiques 3-D du grand sous-bassin d’Ughelli, dans le delta du Niger. Ce travail a permis de prévoir les régimes de pression du

  9. Seismic signatures of the Lodgepole fractured reservoir in Utah-Wyoming overthrust belt

    Parra, J.; Collier, H.; Angstman, B.

    1997-08-01

    In low porosity, low permeability zones, natural fractures are the primary source of permeability which affect both production and injection of fluids. The open fractures do not contribute much to porosity, but they provide an increased drainage network to any porosity. An important approach to characterizing the fracture orientation and fracture permeability of reservoir formations is one based upon the effects of such conditions on the propagation of acoustic and seismic waves in the rock. We present the feasibility of using seismic measurement techniques to map the fracture zones between wells spaced 2400 ft at depths of about 1000 ft. For this purpose we constructed computer models (which include azimuthal anisotropy) using Lodgepole reservoir parameters to predict seismic signatures recorded at the borehole scale, crosswell scale, and 3 D seismic scale. We have integrated well logs with existing 2D surfaces seismic to produce petrophysical and geological cross sections to determine the reservoir parameters and geometry for the computer models. In particular, the model responses are used to evaluate if surface seismic and crosswell seismic measurements can capture the anisotropy due to vertical fractures. Preliminary results suggested that seismic waves transmitted between two wells will propagate in carbonate fracture reservoirs, and the signal can be received above the noise level at the distance of 2400 ft. In addition, the large velocities contrast between the main fracture zone and the underlying unfractured Boundary Ridge Member, suggested that borehole reflection imaging may be appropriate to map and fracture zone thickness variation and fracture distributions in the reservoir.

  10. 3D Visualization of Recent Sumatra Earthquake

    Nayak, Atul; Kilb, Debi

    2005-04-01

    Scientists and visualization experts at the Scripps Institution of Oceanography have created an interactive three-dimensional visualization of the 28 March 2005 magnitude 8.7 earthquake in Sumatra. The visualization shows the earthquake's hypocenter and aftershocks recorded until 29 March 2005, and compares it with the location of the 26 December 2004 magnitude 9 event and the consequent seismicity in that region. The 3D visualization was created using the Fledermaus software developed by Interactive Visualization Systems (http://www.ivs.unb.ca/) and stored as a ``scene'' file. To view this visualization, viewers need to download and install the free viewer program iView3D (http://www.ivs3d.com/products/iview3d).

  11. Rock property estimates using multiple seismic attributes and neural networks; Pegasus Field, West Texas

    Schuelke, J.S.; Quirein, J.A.; Sarg, J.F.

    1998-12-31

    This case study shows the benefit of using multiple seismic trace attributes and the pattern recognition capabilities of neural networks to predict reservoir architecture and porosity distribution in the Pegasus Field, West Texas. The study used the power of neural networks to integrate geologic, borehole and seismic data. Illustrated are the improvements between the new neural network approach and the more traditional method of seismic trace inversion for porosity estimation. Comprehensive statistical methods and interpretational/subjective measures are used in the prediction of porosity from seismic attributes. A 3-D volume of seismic derived porosity estimates for the Devonian reservoir provide a very detailed estimate of porosity, both spatially and vertically, for the field. The additional reservoir porosity detail provided, between the well control, allows for optimal placement of horizontal wells and improved field development. 6 refs., 2 figs.

  12. Imaging 3D geological structure of the Mygdonian basin (Northern Greece) with geological numerical modeling and geophysical methods.

    Cédric, Guyonnet-Benaize; Fabrice, Hollender; Maria, Manakou; Alexandros, Savvaidis; Elena, Zargli; Cécile, Cornou; Nikolaos, Veranis; Dimitrios, Raptakis; Artemios, Atzemoglou; Pierre-Yves, Bard; Nikolaos, Theodulidis; Kyriazis, Pitilakis; Emmanuelle, Chaljub

    2013-04-01

    The Mygdonian basin, located 30 km E-NE close to Thessaloniki, is a typical active tectonic basin, trending E-NW, filled by sediments 200 to 400 m thick. This basin has been chosen as a European experimental site since 1993 (European Commission research projects - EUROSEISTEST). It has been investigated for experimental and theoretical studies on site effects. The Mygdonian basin is currently covered by a permanent seismological network and has been mainly characterized in 2D and 3D with geophysical and geotechnical studies (Bastani et al, 2011; Cadet and Savvaidis, 2011; Gurk et al, 2007; Manakou et al, 2007; Manakou et al, 2010; Pitilakis et al, 1999; Raptakis et al, 2000; Raptakis et al, 2005). All these studies allowed understanding the influence of geological structures and local site conditions on seismic site response. For these reasons, this site has been chosen for a verification exercise for numerical simulations in the framework of an ongoing international collaborative research project (Euroseistest Verification and Validation Project - E2VP). The verification phase has been made using a first 3D geophysical and geotechnical model (Manakou, 2007) about 5 km wide and 15 km long, centered on the Euroseistest site. After this verification phase, it has been decided to update, optimize and extend this model in order to obtain a more detailed model of the 3D geometry of the entire basin, especially the bedrock 3D geometry which can affect drastically the results of numerical simulations for site effect studies. In our study, we build a 3D geological model of the present-day structure of the entire Mygdonian basin. This "precise" model is 12 km wide, 65 km long and is 400 m deep in average. It has been built using geophysical, geotechnical and geological data. The database is heterogeneous and composed of hydrogeological boreholes, seismic refraction surveys, array microtremor measurements, electrical and geotechnical surveys. We propose an integrated

  13. Building 3D geological knowledge through regional scale gravity modelling for the Bowen Basin

    Danis, Cara; O'Neill, Craig; Lackie, Mark

    2012-01-01

    Regional scale gravity modelling is an effective and fast way to gain geological understanding of large scale structures like the Bowen Basin. Detailed deep 3D geological knowledge has become an important component of many types of exploration and resource modelling. Current interest in the Bowen Basin for geothermal exploration highlights the need for a complete basin scale model which is compatible with thermal modelling software. The structure of the Bowen Basin is characteristic of a typical asymmetrical extensional rift basin, with up to 5km of sediment overlying the basement. By combining gravity modelling, calibrated by boreholes and seismic reflection profiles, we produce geologically reasonable 3D surfaces and structures to create a model of the Bowen Basin. This model is the final part in the completion of the 3D Sydney-Gunnedah-Bowen Basin system geological model and provides both an important framework from which detailed thermal models can be derived and a platform from which to expand with new information.

  14. Near surface characterisation of a limestone site using borehole and surface geophysics.

    Sénéchal, G.; Hollender, F.; Rousset, D.

    2003-04-01

    The paper deals with the analysis of the respective performances and the optimization of geophysical methods used for the non-destructive imagery of rocks, from the surface to a depth of approximately 100 m. Different techniques, carried out from the surface or from boreholes, have been tested on the \\char`&{uml;}Médecin Hill\\char`&{uml;} (Centre d'Etude de Cadarache - 13108 St. Paul lez Durance - France). This test site consists in a low fractured limestone, crossed by several faults characterized by a near-vertical dip. The site was previously investigated by numerous other characterization methods (boreholes, surface geology, structural analysis, well logging, etc.): a well known structural 3D model is available. Each tested geophysical method is based on the determination of different physical parameters (elastic parameters, density, electrical resistivity, dielectric permittivity, etc.). In terms of resolution and depth of investigation, every geophysical method has its own drawbacks and advantages. High resolution seismic focuses between 20 and some hundred of meters of depth with a metric to decametric vertical resolution. GPR has a decimetric resolution but electromagnetic waves are strongly attenuated after a few meters of propagation. DC resistivity is a potential method so, resolution dramatically decreases with depth of investigation. The acquisition pattern of this last study leads to a depth of investigation around 15 m and a resolution of one to several meters. Several surface acquisitions have been performed within a 400 m line along which seven boreholes are located. From the high resolution reflection seismic data, we calculated a depth migrated section which displays the main interfaces affected by some near vertical faults. These results are compared to seismic data obtained from a borehole survey interpreted with the help of log data. A radar borehole survey, using tomographic and reflection pattern surveys provided improved information but

  15. 3D Spectroscopic Instrumentation

    Bershady, Matthew A

    2009-01-01

    In this Chapter we review the challenges of, and opportunities for, 3D spectroscopy, and how these have lead to new and different approaches to sampling astronomical information. We describe and categorize existing instruments on 4m and 10m telescopes. Our primary focus is on grating-dispersed spectrographs. We discuss how to optimize dispersive elements, such as VPH gratings, to achieve adequate spectral resolution, high throughput, and efficient data packing to maximize spatial sampling for 3D spectroscopy. We review and compare the various coupling methods that make these spectrographs ``3D,'' including fibers, lenslets, slicers, and filtered multi-slits. We also describe Fabry-Perot and spatial-heterodyne interferometers, pointing out their advantages as field-widened systems relative to conventional, grating-dispersed spectrographs. We explore the parameter space all these instruments sample, highlighting regimes open for exploitation. Present instruments provide a foil for future development. We give an...

  16. 3D Projection Installations

    Halskov, Kim; Johansen, Stine Liv; Bach Mikkelsen, Michelle

    2014-01-01

    Three-dimensional projection installations are particular kinds of augmented spaces in which a digital 3-D model is projected onto a physical three-dimensional object, thereby fusing the digital content and the physical object. Based on interaction design research and media studies, this article...... contributes to the understanding of the distinctive characteristics of such a new medium, and identifies three strategies for designing 3-D projection installations: establishing space; interplay between the digital and the physical; and transformation of materiality. The principal empirical case, From...... Fingerplan to Loop City, is a 3-D projection installation presenting the history and future of city planning for the Copenhagen area in Denmark. The installation was presented as part of the 12th Architecture Biennale in Venice in 2010....

  17. 3D geological interpretation of geophysical profiles and further 3D geological modelling at LLWR Site and surrounding area

    Smith, N; Auton, C.; Kearsey, T.; Finlayson, A; Callaghan, E.

    2010-01-01

    The report encompasses four pieces of work undertaken on behalf of LLWR Ltd during 2010: 1) A description of the interpretation of geophysical profiles obtained from the Drigg Spit area were revised in a 3D environment in order to address inconsistencies along the profiles where they intersected. Profile interpretations were revised using GSI3D software, by examining both the original geophysical profile, the existing interpretation and geological information from boreholes ...

  18. Herramientas SIG 3D

    Francisco R. Feito Higueruela

    2010-04-01

    Full Text Available Applications of Geographical Information Systems on several Archeology fields have been increasing during the last years. Recent avances in these technologies make possible to work with more realistic 3D models. In this paper we introduce a new paradigm for this system, the GIS Thetrahedron, in which we define the fundamental elements of GIS, in order to provide a better understanding of their capabilities. At the same time the basic 3D characteristics of some comercial and open source software are described, as well as the application to some samples on archeological researchs

  19. Bootstrapping 3D fermions

    Iliesiu, Luca; Kos, Filip; Poland, David; Pufu, Silviu S.; Simmons-Duffin, David; Yacoby, Ran

    2016-03-01

    We study the conformal bootstrap for a 4-point function of fermions in 3D. We first introduce an embedding formalism for 3D spinors and compute the conformal blocks appearing in fermion 4-point functions. Using these results, we find general bounds on the dimensions of operators appearing in the ψ × ψ OPE, and also on the central charge C T . We observe features in our bounds that coincide with scaling dimensions in the GrossNeveu models at large N . We also speculate that other features could coincide with a fermionic CFT containing no relevant scalar operators.

  20. Interaktiv 3D design

    Villaume, René Domine; Ørstrup, Finn Rude

    2002-01-01

    Projektet undersøger potentialet for interaktiv 3D design via Internettet. Arkitekt Jørn Utzons projekt til Espansiva blev udviklet som et byggesystem med det mål, at kunne skabe mangfoldige planmuligheder og mangfoldige facade- og rumudformninger. Systemets bygningskomponenter er digitaliseret som...... 3D elementer og gjort tilgængelige. Via Internettet er det nu muligt at sammenstille og afprøve en uendelig  række bygningstyper som  systemet blev tænkt og udviklet til....

  1. 3D Dental Scanner

    Kotek, L.

    2015-01-01

    This paper is about 3D scan of plaster dental casts. The main aim of the work is a hardware and software proposition of 3D scan system for scanning of dental casts. There were used camera, projector and rotate table for this scanning system. Surface triangulation was used, taking benefits of projections of structured light on object, which is being scanned. The rotate table is controlled by PC. The camera, projector and rotate table are synchronized by PC. Controlling of stepper motor is prov...

  2. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-01-01

    In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot o...

  3. Tangible 3D Modelling

    Hejlesen, Aske K.; Ovesen, Nis

    2012-01-01

    This paper presents an experimental approach to teaching 3D modelling techniques in an Industrial Design programme. The approach includes the use of tangible free form models as tools for improving the overall learning. The paper is based on lecturer and student experiences obtained through...

  4. Shaping 3-D boxes

    Stenholt, Rasmus; Madsen, Claus B.

    2011-01-01

    Enabling users to shape 3-D boxes in immersive virtual environments is a non-trivial problem. In this paper, a new family of techniques for creating rectangular boxes of arbitrary position, orientation, and size is presented and evaluated. These new techniques are based solely on position data...

  5. 3D Harmonic Echocardiography:

    M.M. Voormolen

    2007-01-01

    textabstractThree dimensional (3D) echocardiography has recently developed from an experimental technique in the ’90 towards an imaging modality for the daily clinical practice. This dissertation describes the considerations, implementation, validation and clinical application of a unique

  6. Characteristics of the crustal magma body in the 2005-06 eruption area at 9°50'N on the East Pacific Rise from a 3D multi-channel seismic investigation

    Carton, H.; Carbotte, S. M.; Mutter, J. C.; Canales, J. P.; Nedimovic, M. R.; Newman, K. R.; Marjanovic, M.; Xu, M.; Aghaei, O.; Stowe, L.

    2008-12-01

    In July-August 2008 the first 3D academic multi-streamer seismic survey was carried out aboard R/V Langseth, focusing on the 9°50'N Integrated Study Site (ISS) at the East Pacific Rise. Preliminary results from 2D processing of along-axis and across-axis grid lines provide insight into the architecture of the magmatic system at the ISS and its relationship with hydrothermal activity and volcanic/dyking events associated with the 2005-06 eruption. Segmentation at length scales of about 5-10km of the axial magmatic system of the 9°50'N area can be mapped based on variations in two-way travel time, reflection strength and along-axis dip of the axial magma chamber (AMC) reflector on the stack sections, as well as the presence of edge diffractions. The main hydrothermal vents around 9°50'N are located over the region of shallowest AMC, which can be divided into two sub-regions, between 9°45.2'N - 9°48.7'N and 9°48.7'N - 9°51.9'N, respectively, separated by a discontinuity that has been interpreted as a potential hydrothermal downflow zone based on microseismicity studies. The northern lens event is rather flat-lying, while the southern one is more complex, dips south and shows pronounced edge diffractions. Both of these shallow lenses display distinctly weaker amplitudes than AMC reflections located immediately to the north and south. Lava flows from the most recent eruption overlie these two 'dim' lenses, and also extend over part of the north-dipping, brighter AMC to the north. Though detailed quantification is required, such along-axis variations in reflection strength are suggestive of a lower present-day melt percentage between 9°45.2'N - 9°51.9'N, an observation consistent with melt being drained by the 1991 and 2005-06 eruptions.

  7. Reflection seismic methods applied to locating fracture zones in crystalline rock

    where surface mapped fracture zones exist. The South dipping reflector correlates with the top of a heavily fractured interval observed in a borehole at about 400 m. 3D effects are clearly apparent in the data and only where the profiles cross can the true orientation of the reflecting events be determined. To properly orient and locate all events observed on the lines requires acquisition of 3D data

  8. 3D animace

    Klusoň, Jindřich

    2010-01-01

    Computer animation has a growing importance and application in the world. With expansion of technologies increases quality of the final animation as well as number of 3D animation software. This thesis is currently mapped animation software for creating animation in film, television industry and video games which are advisable users requirements. Of them were selected according to criteria the best - Autodesk Maya 2011. This animation software is unique with tools for creating special effects...

  9. Compiling geophysical and geological information into a 3-D model of the glacially-affected island of Föhr

    T. Burschil

    2012-10-01

    Full Text Available Within the scope of climatic change and associated sea level rise, coastal aquifers are endangered and are becoming more a focus of research to ensure the future water supply in coastal areas. For groundwater modelling a good understanding of the geological/hydrogeological situation and the aquifer behavior is necessary. In preparation of groundwater modelling and assessment of climate change impacts on coastal water resources, we setup a geological/hydrogeological model for the North Sea Island of Föhr.

    Data from different geophysical methods applied from the air, the surface and in boreholes contribute to the 3-D model, e.g. airborne electromagnetics (SkyTEM for spatial mapping the resistivity of the entire island, seismic reflections for detailed cross-sections in the groundwater catchment area, and geophysical borehole logging for calibration of these measurements. An iterative and integrated evaluation of the results from the different geophysical methods contributes to reliable data as input for the 3-D model covering the whole island and not just the well fields.

    The complex subsurface structure of the island is revealed. The local waterworks use a freshwater body embedded in saline groundwater. Several glaciations reordered the youngest Tertiary and Quaternary sediments by glaciotectonic thrust faulting, as well as incision and refill of glacial valleys. Both subsurface structures have a strong impact on the distribution of freshwater-bearing aquifers. A digital geological 3-D model reproduces the hydrogeological structure of the island as a base for a groundwater model. In the course of the data interpretation, we deliver a basis for rock identification.

    We demonstrate that geophysical investigation provide petrophysical parameters and improve the understanding of the subsurface and the groundwater system. The main benefit of our work is that the successful combination of electromagnetic, seismic and borehole

  10. Seismic VSP Investigations at Olkiluoto, 2005

    Posiva Oy carries out R and D related tasks for spent nuclear fuel disposal in Finland. The site characterization has been conducted since 1987 in Olkiluoto in western Finland. The ONKALO underground characterization facility has been under construction since 2004. Vibrometric Oy has been contracted to carry out seismic VSP survey in four drillholes in the immediate vicinity of ONKALO, for the characterization of the seismically responsive structures. Four drillholes, KR8, KR27, KR29 and KR38 were included to the project. Seven seismic source locations on ground surface were used for each drillhole. The source locations were optimized with respect to the drillhole and ONKALO and were configured as linear arrays to produce optimum imaging focused on the ONKALO volume. A mechanical Vibsist source, using a hydraulic rock breaker mounted on a 22 t excavator, was used as source of seismic signal. The signal was recorded with downhole 3-component geophones. The recording array was 8-level long, with 5 m spacing between levels. Acquisition was run throughout the drillholes. Processing of the VSP profiles consisted of time decoding of the impact sequences, filtering and image point (IP) transform. The interpretation was carried out interactively, seeking for best match of orientation of each reflection according to different borehole profiles where the features were seen. The interpretations were built as an add-on to a previous seismic model of the site. The most distinct reflectors were interpreted, compiled to as a part of a terrain model composed of 3D surfaces, and transferred digitally together with other results (3D elements of reflector locations) into Posiva's 3D modeling system. Some of the reflectors have already received direct confirmation from ONKALO observations. (orig.)

  11. Massive 3D Supergravity

    Andringa, Roel; de Roo, Mees; Hohm, Olaf; Sezgin, Ergin; Townsend, Paul K

    2009-01-01

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered `massive 3D gravity'. Another is a `new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  12. Massive 3D supergravity

    Andringa, Roel; Bergshoeff, Eric A; De Roo, Mees; Hohm, Olaf [Centre for Theoretical Physics, University of Groningen, Nijenborgh 4, 9747 AG Groningen (Netherlands); Sezgin, Ergin [George and Cynthia Woods Mitchell Institute for Fundamental Physics and Astronomy, Texas A and M University, College Station, TX 77843 (United States); Townsend, Paul K, E-mail: E.A.Bergshoeff@rug.n, E-mail: O.Hohm@rug.n, E-mail: sezgin@tamu.ed, E-mail: P.K.Townsend@damtp.cam.ac.u [Department of Applied Mathematics and Theoretical Physics, Centre for Mathematical Sciences, University of Cambridge, Wilberforce Road, Cambridge, CB3 0WA (United Kingdom)

    2010-01-21

    We construct the N=1 three-dimensional supergravity theory with cosmological, Einstein-Hilbert, Lorentz Chern-Simons, and general curvature squared terms. We determine the general supersymmetric configuration, and find a family of supersymmetric adS vacua with the supersymmetric Minkowski vacuum as a limiting case. Linearizing about the Minkowski vacuum, we find three classes of unitary theories; one is the supersymmetric extension of the recently discovered 'massive 3D gravity'. Another is a 'new topologically massive supergravity' (with no Einstein-Hilbert term) that propagates a single (2,3/2) helicity supermultiplet.

  13. Salt movements in the Northeast German Basin and its relation to major post-Permian tectonic phases—results from 3D structural modelling, backstripping and reflection seismic data

    Scheck, Magdalena; Bayer, Ulf; Lewerenz, Björn

    2003-01-01

    The NW-SE-striking Northeast German Basin (NEGB) forms part of the Southern Permian Basin and contains up to 8 km of Permian to Cenozoic deposits. During its polyphase evolution, mobilization of the Zechstein salt layer resulted in a complex structural configuration with thin-skinned deformation in the basin and thick-skinned deformation at the basin margins. We investigated the role of salt as a decoupling horizon between its substratum and its cover during the Mesozoic deformation by integration of 3D structural modelling, backstripping and seismic interpretation. Our results suggest that periods of Mesozoic salt movement correlate temporally with changes of the regional stress field structures. Post-depositional salt mobilisation was weakest in the area of highest initial salt thickness and thickest overburden. This also indicates that regional tectonics is responsible for the initiation of salt movements rather than stratigraphic density inversion. Salt movement mainly took place in post-Muschelkalk times. The onset of salt diapirism with the formation of N-S-oriented rim synclines in Late Triassic was synchronous with the development of the NNE-SSW-striking Rheinsberg Trough due to regional E-W extension. In the Middle and Late Jurassic, uplift affected the northern part of the basin and may have induced south-directed gravity gliding in the salt layer. In the southern part, deposition continued in the Early Cretaceous. However, rotation of salt rim synclines axes to NW-SE as well as accelerated rim syncline subsidence near the NW-SE-striking Gardelegen Fault at the southern basin margin indicates a change from E-W extension to a tectonic regime favoring the activation of NW-SE-oriented structural elements. During the Late Cretaceous-Earliest Cenozoic, diapirism was associated with regional N-S compression and progressed further north and west. The Mesozoic interval was folded with the formation of WNW-trending salt-cored anticlines parallel to inversion

  14. Exploratory borehole Weiach. Working programme

    An extensive geophysical borehole logging programme will serve to verify the results of the core analysis and comlement the core data. Numerous borehole logs are to be registered with different types of tools. These allow one to determine various parameters essential for the full description of the rock sequences penetrated. A first category of logs enables the petrographical identification of the different rock types and indicates porous zones that are either water- or hydrocarbon bearing. A second category provides data e.g. on the degree of pore and fracture fill, rock density and rock temperature, natural gamma radiation and rock-mechanical properties. Other logs measure strike and dip of the sedimentary layers and the position of rock fractures. A fourth category provides information on the diameter and the deviation of the borehole, the quality of casing cementations and the position of casing joints. In addition, well shooting surveys will supply exact values of seismic velocities for the various rock units; data that are needed for the depth correction of the reflection profiles from Nagra's regional seismic network. With numerous hydrological tests ranging from an open-hole production test of the Muschelkalk aquifer to labelled slug tests in low-permeability crystalline sections, the hydraulic conditions of deep groundwater flow will be investigated. The recovered water samples will undergo full physical and geochemical analysis. Furthermore, their isotope content is to be measured in order to estimate the age of the various formation waters. To round off the scientific investigations, a series of rock-mechanical and geotechnical laboratory tests will provide characteristic values to be applied eventually in the design and construction of shafts and caverns for an underground repository

  15. Exploratory borehole Riniken. Working programme

    An extensive geophysical borehole logging programme will serve to verify the results of the core analysis and comlement the core data. Numerous borehole logs are to be registered with different types of tools. These allow one to determine various parameters essential for the full description of the rock sequences penetrated. A first category of logs enables the petrographical identification of the different rock types and indicates porous zones that are either water- or hydrocarbon-bearing. A second category provides data e.g. on the degree of pore and fracture fill, rock density and rock temperature, natural gamma radiation and rock-mechanical properties. Other logs measure strike and dip of the sedimentary layers and the position of rock fractures. A forth category provides information on the diameter and the deviation of the borehole, the quality of casing cementations and the position of casing joints. In addition, well shooting surveys will supply exact values of seismic velocities for the various rock units; data that are needed for the depth correction of the reflection profiles from Nagra's regional seismic network. With numerous hydrological tests ranging from a production test of the Muschelkalk aquifer to labelled slug tests in low-permeability crystalline sections, the hydraulic conditions of deep groundwater flow will be investigated. The recovered water samples will undergo full physical and geochemical analysis. Furthermore, their isotope content is to be measured in order to estimate the age of the various formation waters and their time of residence in the subsurface. To round off the scientific investigations, a series of rock-mechanical and geotechnical laboratory tests will provide characteristic values to be applied eventually in the design and construction of shafts and caverns for an underground repository

  16. Exploratory borehole Leuggern. Working program

    An extensive geophysical borehole logging programme will serve to verify the results of the core analysis and complement the core data. Numerous borehole logs are to be registered with different types of tools. These allow one to determine various parameters essential for the full description of the rock sequences penetrated. A first category of logs enables the petrographical identification of the different rock types and indicates porous zones that are either water- or hydrocarbon-bearing. A second category provides data e.g. on the degree of pore and fracture fill, rock density and rock temperature, natural gamma radiation and rock-mechanical properties. Other logs measure strike and dip of the sedimentary layers and the position of rock fractures. A fourth category provides information on the diameter and the deviation of the borehole, the quality of casing cementations and the position of casing joints. In addition, well shooting surveys will supply exact values of seismic velocities for the various rock units; data that are needed for the depth correction of the reflection profiles from Nagra's regional seismic network. With numerous hydrological tests ranging from a production tests of the Muschelkalk and Buntsandstein aquifers to labelled slug-tests in low-permeability crystalline sections, the hydraulic conditions of deep groundwater flow will be investigated. The recovered water samples will undergo full physical and geochemical analysis. Furthermore, their isotope content is to be measured in order to estimate the age of the various formation waters and their time of residence in the subsurface. To round off the scientific investigations, a series of rock-mechanical and geotechnical laboratory tests will provide characteristic values to be applied eventually in the design and construction of shafts and caverns for an underground repository

  17. Exploratory borehole Kaisten. Working program

    The next well on the Nagra drilling programme, Kaisten, lies at the southern border of the Rhine valley. An extensive geophysical borehole logging programme will serve to verify the results of the core analysis and complement the core data. Numerous borehole logs are to be registered with different types of tools. These allow one to determine various parameters essential for the full description of the rock sequences penetrated. A first category of logs enables the petrographical identification of the different rock types and indicates porous zones that are either water- or hydrocarbon-bearing. A second category provides data e.g. on the degree of pore and fracture fill, rock density and rock temperature, natural gamma radiation and rock-mechanical properties. Other logs measure strike and dip of the sedimentary layers and the position of rock fractures. A fourth category provides information on the diameter and the deviation of the borehole, the quality of casing cementations and the position of casing joints. In addition, well shooting surveys will supply exact values of seismic velocities for the various rock units; data that are needed for the depth correction of the reflection profiles from Nagra's regional seismic network. With numerous hydrological tests ranging from production tests of the Buntsandstein aquifer to labelled slug-tests in low-permeability crystalline sections, the hydraulic conditions of deep groundwater flow will be investigated. The recovered water samples will undergo full physical and geochemical analysis. Furthermore, their isotope content is to be measured in order to estimate the age of the various formation waters and their time of residence in the subsurface

  18. TOWARDS: 3D INTERNET

    Ms. Swapnali R. Ghadge

    2013-08-01

    Full Text Available In today’s ever-shifting media landscape, it can be a complex task to find effective ways to reach your desired audience. As traditional media such as television continue to lose audience share, one venue in particular stands out for its ability to attract highly motivated audiences and for its tremendous growth potential the 3D Internet. The concept of '3D Internet' has recently come into the spotlight in the R&D arena, catching the attention of many people, and leading to a lot of discussions. Basically, one can look into this matter from a few different perspectives: visualization and representation of information, and creation and transportation of information, among others. All of them still constitute research challenges, as no products or services are yet available or foreseen for the near future. Nevertheless, one can try to envisage the directions that can be taken towards achieving this goal. People who take part in virtual worlds stay online longer with a heightened level of interest. To take advantage of that interest, diverse businesses and organizations have claimed an early stake in this fast-growing market. They include technology leaders such as IBM, Microsoft, and Cisco, companies such as BMW, Toyota, Circuit City, Coca Cola, and Calvin Klein, and scores of universities, including Harvard, Stanford and Penn State.

  19. Reflection seismic studies at the Laxemar area

    Two 2 km long crossing lines with high-resolution reflection seismics were acquired at Laxemar, close to The Aespoe Hard Rock Laboratory, in December 1999. The main goal with the investigation was to make a full-scale test of developed methods in reflection seismics with the use of small shotholes and small explosive charges. The secondary goal was to identify fracture zones that might correlate with water bearing fracture zones found in boreholes. Both lines had 10-meter separation between the geophones and charge holes. Shot sizes were 15-gram plastic explosives for shots in rock and 75-gram ones for shots in lose sediments and till. The results from the measurements show that the small shotholes technique and small charges works well to investigate the rock down to a depth of 3-4 kilometers. The signal penetrates at least to 1500-metres (500 ms travel time for the seismic signal) along both lines. Over some parts of the lines the seismic signal penetrates to c. 6000- metres (2 seconds travel time). Five dipping reflectors (c. 30-50 deg) can be identified. Three of these can be projected up to the surface on both lines and their 3D orientation can be determined. These reflectors also coincide with topographical depressions. The two other dipping reflectors are only visible on one line, but can be assumed to correlate with topographical depressions and that way be assigned a three dimensional orientation. Four of the reflectors correlate with previously mapped fracture zones. A zone of sub-horizontal reflectivity (0-15 deg) is visible at 650-900 meters depth where the lines cross the deep borehole KLX02. This zone dips gently towards the east and can be correlated with sections of greenstones found in KLX02. The zone of sub-horizontal reflectivity continues to the deep borehole KLX01, but is not as clear here. This sub-horizontal zone may be the hydraulic connection between the boreholes in their deeper part. Deeper down at 1100 ms (c. 3 km), there are strong

  20. Developments of borehole strain observation outside China

    邱泽华; 石耀霖

    2004-01-01

    Borehole strain observation is playing an increasingly important role in the study on the crustal movements. It hasbeen used by many countries such as China, USA, Japan, Peru, Australia, South Africa, Iceland and Italy, in research fields of plate tectonics, earthquake, volcanic eruption, dam safety, oil field subsidence, mining collapse andso on. Borehole strainmeter has been improved rapidly and tends to get more and more components included inone probe. Based on observations by this kind of instruments, studies on seismic strain step, slow earthquake,earthquake precursor and volcanic eruption forecasting have made remarkable achievements. In the coming years,borehole strain observation is going to become one major geodetic means, together with GPS and InSAR.

  1. Effect of borehole design on electrical impedance tomography measurements

    Mozaffari, Amirpasha; Huisman, Johan Alexander; Treichel, Andrea; Zimmermann, Egon; Kelter, Matthias; Vereecken, Harry

    2015-04-01

    Electrical Impedance Tomography (EIT) is a sophisticated non-invasive tool to investigate the subsurface in engineering and environmental studies. To increase the depth of investigation, EIT measurements can be made in boreholes. However, the presence of the borehole may affect EIT measurements. Here, we aim to investigate the effect of different borehole components on EIT measurements using 2,5-D and 3D finite element modeling and unstructured meshes. To investigate the effect of different borehole components on EIT measurements, a variety of scenarios were designed. In particular, the effect of the water-filled borehole, the PVC casing, and the gravel filter were investigated relative to complex resistivity simulations for a homogenous medium with chain and electrode modules. It was found that the results of the complex resistivity simulations were best understood using the sensitivity distribution of the electrode configuration under consideration. In all simulations, the sensitivity in the vicinity of the borehole was predominantly negative. Therefore, the introduction of the water-filled borehole caused an increase in the real part of the impedance, and a decrease (more negative) in the imaginary part of the simulated impedance. The PVC casing mostly enhanced the effect of the water-filled borehole described above, although this effect was less clear for some electrode configuration. The effect of the gravel filter mostly reduced the effect of the water-filled borehole with PVC casing. For EIT measurements in a single borehole, the highest simulated phase error was 12% for a Wenner configuration with electrode spacing of 0.33 m. This error decreased with increasing electrode spacing. In the case of cross-well configurations, the error in the phase shit was as high as 6%. Here, it was found that the highest errors occur when both current electrodes are located in the same borehole. These results indicated that cross-well measurements are less affected by the

  2. Is 3D true non linear traveltime tomography reasonable ?

    Herrero, A.; Virieux, J.

    2003-04-01

    The data sets requiring 3D analysis tools in the context of seismic exploration (both onshore and offshore experiments) or natural seismicity (micro seismicity surveys or post event measurements) are more and more numerous. Classical linearized tomographies and also earthquake localisation codes need an accurate 3D background velocity model. However, if the medium is complex and a priori information not available, a 1D analysis is not able to provide an adequate background velocity image. Moreover, the design of the acquisition layouts is often intrinsically 3D and renders difficult even 2D approaches, especially in natural seismicity cases. Thus, the solution relies on the use of a 3D true non linear approach, which allows to explore the model space and to identify an optimal velocity image. The problem becomes then practical and its feasibility depends on the available computing resources (memory and time). In this presentation, we show that facing a 3D traveltime tomography problem with an extensive non-linear approach combining fast travel time estimators based on level set methods and optimisation techniques such as multiscale strategy is feasible. Moreover, because management of inhomogeneous inversion parameters is more friendly in a non linear approach, we describe how to perform a jointly non-linear inversion for the seismic velocities and the sources locations.

  3. High-resolution seismic reflection survey near SPR surface collapse feature at Weeks Island, Louisiana

    Miller, R.D.; Xia, J. [Kansas Geological Survey, Lawrence, KS (United States); Harding, R.S. Jr. [Sandia National Labs., Albuquerque, NM (United States); Steeples, D.W. [Univ. of Kansas, Lawrence, KS (United States)

    1994-12-31

    Shallow high resolution 2-D and 3-D seismic reflection techniques are assisting in the subsurface delineation of a surface collapse feature (sinkhole) at Weeks Island, Louisiana. Seismic reflection surveys were conducted in March 1994. Data from walkaway noise tests were used to assist selection of field recording parameters. The top of the salt dome is about 180 ft below ground surface at the sinkhole. The water table is an estimated 90 ft below the ground surface. A single coherent reflection was consistently recorded across the entire area of the survey, although stacking velocity and spectral content of the event varied. On the basis of observed travel times and stacking velocities, the coherent reflection event appears to originate above the top of the salt, possibly at or near the water table. Identification of this reflector will be made form borehole investigations currently planned for the sinkhole site. A depression or time sag in this reflection event is clearly evident in both the 2-D and 3-D seismic data in the immediate vicinity of the sinkhole. The time sag appears to be related to the subsurface structure of the reflector and not to near surface topography or velocity effects. Elsewhere in the survey area, observed changes in reflection travel times and wavelet character appear to be related to subsurface geologic structure. These seismic observations may assist in predicting where future sinkholes will develop after they have been tied to borehole data collected at the site.

  4. 3D printing for dummies

    Hausman, Kalani Kirk

    2014-01-01

    Get started printing out 3D objects quickly and inexpensively! 3D printing is no longer just a figment of your imagination. This remarkable technology is coming to the masses with the growing availability of 3D printers. 3D printers create 3-dimensional layered models and they allow users to create prototypes that use multiple materials and colors.  This friendly-but-straightforward guide examines each type of 3D printing technology available today and gives artists, entrepreneurs, engineers, and hobbyists insight into the amazing things 3D printing has to offer. You'll discover methods for

  5. Multiscale joint interpretation of seismic and magnetotelluric data in Hontomín (Spain): From shallow subsurface to reservoir.

    Ogaya, Xènia; Alcalde, Juan; Marzán, Ignacio; Ledo, Juanjo; Queralt, Pilar; Marcuello, Alex; Saura, Eduard; Martí, David; Carbonell, Ramón; Benjumea, Beatriz

    2016-04-01

    The village of Hontomín (north of Spain) hosts the first Technological Development Plant (TDP) for CO2 geological storage located in Spain. The study area has been extensively surveyed to produce a multidisciplinary characterisation, including a 36 km2 3D seismic survey and a circumscribed 15 km2 3D magnetotelluric (MT) survey. In this work, we use the outcomes of these two methods to produce a combined characterisation of the subsurface of Hontomín. This characterisation is carried out at three different scales: reservoir, borehole and shallow subsurface. (1) At reservoir scale, characterisation is obtained by comparing the 3D structural model, obtained from the interpretation of the seismic dataset, with the resistivity model obtained from the 3D MT survey. This joint interpretation highlights the similarities and disagreements between the two models, which informs of their good complementarity. (2) At borehole scale, there is an outstanding correlation between the resistivity logs and the resistivity model obtained by the inversion of the 3D MT data. This allowed building resistivity-velocity pairs from the wireline-log data across the entire sedimentary sequence with confidence, and furthermore computing resistivity-velocity relationships for each formation. These relationships are used to calculate a 3D velocity model from the resistivity model. The agreement between the two velocity models is evaluated at the target depth (reservoir and seal formations). (3) At shallow subsurface (40 m depth), the derived velocity model is compared to the inverted model used in the static correction calculations in the seismic data. The results allowed extracting information about the characteristics of the shallow sediments, suggesting geometry and location of potential karstic structures present in the study area. This work explores the compatibility of the seismic and magnetotelluric methods across scales highlighting the importance of joint interpretation in

  6. 3D monitor

    Szkandera, Jan

    2009-01-01

    Tato bakalářská práce se zabývá návrhem a realizací systému, který umožní obraz scény zobrazovaný na ploše vnímat prostorově. Prostorové vnímání 2D obrazové informace je umožněno jednak stereopromítáním a jednak tím, že se obraz mění v závislosti na poloze pozorovatele. Tato práce se zabývá hlavně druhým z těchto problémů. This Bachelor's thesis goal is to design and realize system, which allows user to perceive 2D visual information as three-dimensional. 3D visual preception of 2D image i...

  7. Mobile 3D tomograph

    Mobile tomographs often have the problem that high spatial resolution is impossible owing to the position or setup of the tomograph. While the tree tomograph developed by Messrs. Isotopenforschung Dr. Sauerwein GmbH worked well in practice, it is no longer used as the spatial resolution and measuring time are insufficient for many modern applications. The paper shows that the mechanical base of the method is sufficient for 3D CT measurements with modern detectors and X-ray tubes. CT measurements with very good statistics take less than 10 min. This means that mobile systems can be used, e.g. in examinations of non-transportable cultural objects or monuments. Enhancement of the spatial resolution of mobile tomographs capable of measuring in any position is made difficult by the fact that the tomograph has moving parts and will therefore have weight shifts. With the aid of tomographies whose spatial resolution is far higher than the mechanical accuracy, a correction method is presented for direct integration of the Feldkamp algorithm

  8. Scientific investigation in deep boreholes at the Meuse/Haute Marne underground research laboratory, northeastern France

    From 1994 to 1996, the preliminary investigation carried out by Andra, identified a sector favourable for hosting a laboratory in argillaceous Callovo-Oxfordian formation which has a thickness of 130 m and lies more than 400 m below ground level. In November 1999 Andra began building an Underground Research Laboratory (URL) with a 3D seismic survey over 4 km2. From 2000 to 2004, large programs of boreholes were carried out on site and on the sector in order to define the characteristics of formations, to improve the regional geological and hydrogeological knowledge and to provide an accurate definition of structural features in Callovo-Oxfordian argillites and Dogger limestones. These drilling programs have provided a fine characterization of the argillites on the laboratory area and a good correlation of geological properties at a sector scale. (author)

  9. X3D: Extensible 3D Graphics Standard

    Daly, Leonard; Brutzman, Don

    2007-01-01

    The article of record as published may be located at http://dx.doi.org/10.1109/MSP.2007.905889 Extensible 3D (X3D) is the open standard for Web-delivered three-dimensional (3D) graphics. It specifies a declarative geometry definition language, a run-time engine, and an application program interface (API) that provide an interactive, animated, real-time environment for 3D graphics. The X3D specification documents are freely available, the standard can be used without paying any royalties,...

  10. 3D game environments create professional 3D game worlds

    Ahearn, Luke

    2008-01-01

    The ultimate resource to help you create triple-A quality art for a variety of game worlds; 3D Game Environments offers detailed tutorials on creating 3D models, applying 2D art to 3D models, and clear concise advice on issues of efficiency and optimization for a 3D game engine. Using Photoshop and 3ds Max as his primary tools, Luke Ahearn explains how to create realistic textures from photo source and uses a variety of techniques to portray dynamic and believable game worlds.From a modern city to a steamy jungle, learn about the planning and technological considerations for 3D modelin

  11. 3D Printing an Octohedron

    Aboufadel, Edward F.

    2014-01-01

    The purpose of this short paper is to describe a project to manufacture a regular octohedron on a 3D printer. We assume that the reader is familiar with the basics of 3D printing. In the project, we use fundamental ideas to calculate the vertices and faces of an octohedron. Then, we utilize the OPENSCAD program to create a virtual 3D model and an STereoLithography (.stl) file that can be used by a 3D printer.

  12. New developments in high resolution borehole seismology and their applications to reservoir development and management

    Paulsson, B.N.P. [Chevron Petroleum Technology Company, La Habra, CA (United States)

    1997-08-01

    Single-well seismology, Reverse Vertical Seismic Profiles (VSP`s) and Crosswell seismology are three new seismic techniques that we jointly refer to as borehole seismology. Borehole seismic techniques are of great interest because they can obtain much higher resolution images of oil and gas reservoirs than what is obtainable with currently used seismic techniques. The quality of oil and gas reservoir management decisions depend on the knowledge of both the large and the fine scale features in the reservoirs. Borehole seismology is capable of mapping reservoirs with an order of magnitude improvement in resolution compared with currently used technology. In borehole seismology we use a high frequency seismic source in an oil or gas well and record the signal in the same well, in other wells, or on the surface of the earth.

  13. 3D modelling and recognition

    Rodrigues, Marcos; Robinson, Alan; Alboul, Lyuba; Brink, Willie

    2006-01-01

    3D face recognition is an open field. In this paper we present a method for 3D facial recognition based on Principal Components Analysis. The method uses a relatively large number of facial measurements and ratios and yields reliable recognition. We also highlight our approach to sensor development for fast 3D model acquisition and automatic facial feature extraction.

  14. A web-based 3D geological information visualization system

    Song, Renbo; Jiang, Nan

    2013-03-01

    Construction of 3D geological visualization system has attracted much more concern in GIS, computer modeling, simulation and visualization fields. It not only can effectively help geological interpretation and analysis work, but also can it can help leveling up geosciences professional education. In this paper, an applet-based method was introduced for developing a web-based 3D geological information visualization system. The main aims of this paper are to explore a rapid and low-cost development method for constructing a web-based 3D geological system. First, the borehole data stored in Excel spreadsheets was extracted and then stored in SQLSERVER database of a web server. Second, the JDBC data access component was utilized for providing the capability of access the database. Third, the user interface was implemented with applet component embedded in JSP page and the 3D viewing and querying functions were implemented with PickCanvas of Java3D. Last, the borehole data acquired from geological survey were used for test the system, and the test results has shown that related methods of this paper have a certain application values.

  15. INTEGRATED APPROACH FOR THE PETROPHYSICAL INTERPRETATION OF POST- AND PRE-STACK 3-D SEISMIC DATA, WELL-LOG DATA, CORE DATA, GEOLOGICAL INFORMATION AND RESERVOIR PRODUCTION DATA VIA BAYESIAN STOCHASTIC INVERSION

    Carlos Torres-Verdin; Mrinal K. Sen

    2004-03-01

    The present report summarizes the work carried out between September 30, 2002 and August 30, 2003 under DOE research contract No. DE-FC26-00BC15305. During the third year of work for this project we focused primarily on improving the efficiency of inversion algorithms and on developing algorithms for direct estimation of petrophysical parameters. The full waveform inversion algorithm for elastic property estimation was tested rigorously on a personal computer cluster. For sixteen nodes on the cluster the parallel algorithm was found to be scalable with a near linear speedup. This enabled us to invert a 2D seismic line in less than five hours of CPU time. We were invited to write a paper on our results that was subsequently accepted for publication. We also carried out a rigorous study to examine the sensitivity and resolution of seismic data to petrophysical parameters. In other words, we developed a full waveform inversion algorithm that estimates petrophysical parameters such as porosity and saturation from pre-stack seismic waveform data. First we used a modified Biot-Gassmann equation to relate petrophysical parameters to elastic parameters. The transformation was validated with a suite of well logs acquired in the deepwater Gulf of Mexico. As a part of this study, we carried out a sensitivity analysis and found that the porosity is very well resolved while the fluid saturation remains insensitive to seismic wave amplitudes. Finally we conducted a joint inversion of pre-stack seismic waveform and production history data. To overcome the computational difficulties we used a simpler waveform modeling algorithm together with an efficient subspace approach. The algorithm was tested on a realistic synthetic data set. We observed that the use of pre-stack seismic data helps tremendously to improve horizontal resolution of porosity maps. Finally, we submitted four publications to refereed technical journals, two refereed extended abstracts to technical conferences

  16. High resolution 3D nonlinear integrated inversion

    Li Yong; Wang Xuben; Li Zhirong; Li Qiong; Li Zhengwen

    2009-01-01

    The high resolution 3D nonlinear integrated inversion method is based on nonlinear theory. Under layer control, the log data from several wells (or all wells) in the study area and seismic trace data adjacent to the wells are input to a network with multiple inputs and outputs and are integratedly trained to obtain an adaptive weight function of the entire study area. Integrated nonlinear mapping relationships are built and updated by the lateral and vertical geologic variations of the reservoirs. Therefore, the inversion process and its inversion results can be constrained and controlled and a stable seismic inversion section with high resolution with velocity inversion, impedance inversion, and density inversion sections, can be gained. Good geologic effects have been obtained in model computation tests and real data processing, which verified that this method has high precision, good practicality, and can be used for quantitative reservoir analysis.

  17. Simulation of the thermal borehole resistance in groundwater filled borehole heat exchanger using CFD technique

    A-M. Gustafsson, L. Westerlund

    2010-05-01

    Full Text Available The thermal borehole resistance in a groundwater-filled borehole heat exchanger (BHE is affected of both conductive and convective heat transfer through the borehole water. To calculate this heat transport, different models are required compared to calculation of only conductive heat transfer in a back-filled BHE. In this paper some modelling approximations for groundwater-filled, single U-pipe BHEs were investigated using a 3D CFD model. The purpose is to find approximations that enable to construct a fast, simple model including the convective heat transfer that may be used in thermal response test analyses and BHE design programs. Both total heat transfer calculations (including convective and conductive heat transport and only conductive heat transfer calculations were performed for comparison purposes. The approximations that are investigated are the choice of boundary condition at the U-pipe wall and using a single pipe in the middle of the borehole instead of the U-pipe. For the total heat transfer case, it is shown that the choice of boundary condition hardly affects the calculated borehole thermal resistance. For the only conductive heat transfer case, the choice of boundary condition at the pipe wall gives large differences in the result. It is also shown that using an annulus model (single pipe in the middle of the borehole results in similar heat transfer as the U-pipe model provided that the equivalent radius is chosen appropriately. This approximation can radically decrease the number of calculation cells needed.

  18. Simulation of the thermal borehole resistance in groundwater filled borehole heat exchanger using CFD technique

    Gustafsson, A-M. [Department of Civil, Mining and Environmental Engineering, Lulea University of Technology, SE-971 87 Lulea (Sweden); Westerlund, L. [Department of Applied Physics and Mechanical Engineering, Lulea University of Technology, SE-971 87 Lulea (Sweden)

    2010-07-01

    The thermal borehole resistance in a groundwater-filled borehole heat exchanger (BHE) is affected of both conductive and convective heat transfer through the borehole water. To calculate this heat transport, different models are required compared to calculation of only conductive heat transfer in a back-filled BHE. In this paper some modelling approximations for groundwater-filled, single U-pipe BHEs were investigated using a 3D CFD model. The purpose is to find approximations that enable to construct a fast, simple model including the convective heat transfer that may be used in thermal response test analyses and BHE design programs. Both total heat transfer calculations (including convective and conductive heat transport) and only conductive heat transfer calculations were performed for comparison purposes. The approximations that are investigated are the choice of boundary condition at the U-pipe wall and using a single pipe in the middle of the borehole instead of the U-pipe. For the total heat transfer case, it is shown that the choice of boundary condition hardly affects the calculated borehole thermal resistance. For the only conductive heat transfer case, the choice of boundary condition at the pipe wall gives large differences in the result. It is also shown that using an annulus model (single pipe in the middle of the borehole) results in similar heat transfer as the U-pipe model provided that the equivalent radius is chosen appropriately. This approximation can radically decrease the number of calculation cells needed.

  19. 3-D contextual Bayesian classifiers

    Larsen, Rasmus

    distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is made of a pixel and its four nearest neighbours. We will extend these algorithms to 3-D, i.e. we will specify a simultaneous Gaussian distribution for a pixel and its 6 nearest 3......-D neighbours, and generalise the class variable configuration distributions within the 3-D cross given in 2-D algorithms. The new 3-D algorithms are tested on a synthetic 3-D multivariate dataset....

  20. Taming Supersymmetric Defects in 3d-3d Correspondence

    Gang, Dongmin; Romo, Mauricio; Yamazaki, Masahito

    2015-01-01

    We study knots in 3d Chern-Simons theory with complex gauge group $SL(N,\\mathbb{C})$, in the context of its relation with 3d $\\mathcal{N}=2$ theory (the so-called 3d-3d correspondence). The defect has either co-dimension 2 or co-dimension 4 inside the 6d $(2,0)$ theory, which is compactified on a 3-manifold $\\hat{M}$. We identify such defects in various corners of the 3d-3d correspondence, namely in 3d $SL(N,\\mathbb{C})$ Chern-Simons theory, in 3d $\\mathcal{N}=2$ theory, in 5d $\\mathcal{N}=2$ super Yang-Mills theory, and in the M-theory holographic dual. We can make quantitative checks of the 3d-3d correspondence by computing partition functions at each of these theories. This Letter is a companion to a longer paper, which contains more details and more results.

  1. Seismic interpretation and determination of hydrocarbon prospects in the Moravian part of the Vienna Basin

    North - Moravian part of the Vienna basin belongs to the most researched region in Central Europe in terms of investigation of hydrocarbon deposits. However, implementation of advanced research methods, especially 3D seismic measurements, allows discovery of new hydrocarbon deposits in relatively drill hole examined areas. one One of the main objectives of the work is a determination of prospects of new hydrocarbon deposits based on interpretation of newly realized 3D seismic measurements and correlation of borehole measurements of adjacent drill holes in the area of interest, i.e. contact the Moravian central western slopes and depressions Hodonin-Gbely horst . On the structure, which appears to be the most promising, there is semi-finished, a geological part of the project of proposed drill hole and estimated hydrocarbon reserves are calculated simultaneously. (authors)

  2. Co-ordinated research programme on benchmark study for the seismic analysis and testing of WWER-type nuclear power plants. V. 3D. Kozloduy NPP units 5/6: Analysis/testing. Working material

    The Co-ordinated research programme on the benchmark study for the seismic analysis and testing of WWER-type nuclear power plants was initiated subsequent to the request from representatives of Member States. The conclusions adopted at the Technical Committee Meeting on Seismic Issues related to existing nuclear power plants held in Tokyo in 1991 called for the harmonization of methods and criteria used in Member States in issues related to seismic safety. The Consulltants' Meeting which followed resulted in producing a working document for CRP. It was decided that a benchmark study is the most effective way to achieve the principal objective. Two types of WWER reactors (WWER-440/213 and WWER-1000) were selected as prototypes for the benchmark exercise to be tested on a full scale using explosions and/or vibration generators. This volume of Working Material contains reports related dynamic analysis of the primary system of Kozloduy WWER-1000 for soft soil conditions; upper range design response for soft soil sites conditions; and derivation of design response spectra for testing of systems and components

  3. TV-2 test borehole

    A new test borehole was drilled for testing logging radiometers for uranium surveying and for dimensioning logging cables. The borehole is 660 m deep and located in it are 4 artificial radioactivity anomalies. The uncased interval is 120 m long, it has significant differences in resistance (200 to 14 000 Ωm) and makes it possible to test all types of electric logging probes. The test borehole makes possible the control of logging instruments after repair in the field, the testing of new probes prior to their being put into operation, the quality and quick dimensioning of logging cables and the performing of developmental and methodological measurements. (A.K.)

  4. 混凝土重力坝全坝段三维动力分析%Seismic analyses of concrete gravity dam with 3D full-dam model

    王海波; 杨会臣

    2011-01-01

    Seismic analyses of concrete gravity dams are usually idealized as two-dimensional structures.For gravity dams built in narrow valleys or on sites of high seismicity,however,interaction between adjacent dam blocks may influence their seismic responses significantly.In this paper,a three-dimensional full-dam FEM model are adopted to analyze the seismic responses of a concrete gravity dam,with consideration of the dynamic interaction between dam-foundation,dam-water,energy radiation and dynamic contact of monoliths,etc.Comparison are made between the numerical results of single-monolith model,massless-foundation full-dam model and full-dam model with or without contraction joints.The influences of various factors are discussed and engineering measures for improvement of aseismic ability of gravity dams are suggested.%混凝土重力坝抗震分析多针对典型坝段采用二维模型进行。但对于较窄河谷、地震烈度较高等情况,坝段间的动力相互作用对重力坝的地震影响不可忽视。本文采用全坝段三维有限元模型、计入地基辐射阻尼、坝段间动态接触等影响混凝土重力坝地震响应的关键因素,研究分析高烈度区混凝土重力坝地震响应,并与坝段三维模型、无质量地基模型、无横缝整体坝模型的分析结果进行对比,揭示各种因素对混凝土重力坝地震响应的影响,并提出提高坝体抗震能力的工程措施。

  5. 3D Printing Functional Nanocomposites

    Leong, Yew Juan

    2016-01-01

    3D printing presents the ability of rapid prototyping and rapid manufacturing. Techniques such as stereolithography (SLA) and fused deposition molding (FDM) have been developed and utilized since the inception of 3D printing. In such techniques, polymers represent the most commonly used material for 3D printing due to material properties such as thermo plasticity as well as its ability to be polymerized from monomers. Polymer nanocomposites are polymers with nanomaterials composited into the ...

  6. 3D Elevation Program—Virtual USA in 3D

    Lukas, Vicki; Stoker, J.M.

    2016-01-01

    The U.S. Geological Survey (USGS) 3D Elevation Program (3DEP) uses a laser system called ‘lidar’ (light detection and ranging) to create a virtual reality map of the Nation that is very accurate. 3D maps have many uses with new uses being discovered all the time.  

  7. 3D IBFV : Hardware-Accelerated 3D Flow Visualization

    Telea, Alexandru; Wijk, Jarke J. van

    2003-01-01

    We present a hardware-accelerated method for visualizing 3D flow fields. The method is based on insertion, advection, and decay of dye. To this aim, we extend the texture-based IBFV technique for 2D flow visualization in two main directions. First, we decompose the 3D flow visualization problem in a

  8. 3D for Graphic Designers

    Connell, Ellery

    2011-01-01

    Helping graphic designers expand their 2D skills into the 3D space The trend in graphic design is towards 3D, with the demand for motion graphics, animation, photorealism, and interactivity rapidly increasing. And with the meteoric rise of iPads, smartphones, and other interactive devices, the design landscape is changing faster than ever.2D digital artists who need a quick and efficient way to join this brave new world will want 3D for Graphic Designers. Readers get hands-on basic training in working in the 3D space, including product design, industrial design and visualization, modeling, ani

  9. A 3-D Contextual Classifier

    Larsen, Rasmus

    1997-01-01

    . This includes the specification of a Gaussian distribution for the pixel values as well as a prior distribution for the configuration of class variables within the cross that is m ade of a pixel and its four nearest neighbours. We will extend this algorithm to 3-D, i.e. we will specify a simultaneous Gaussian...... distr ibution for a pixel and its 6 nearest 3-D neighbours, and generalise the class variable configuration distribution within the 3-D cross. The algorithm is tested on a synthetic 3-D multivariate dataset....

  10. 3D Bayesian contextual classifiers

    Larsen, Rasmus

    2000-01-01

    We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours.......We extend a series of multivariate Bayesian 2-D contextual classifiers to 3-D by specifying a simultaneous Gaussian distribution for the feature vectors as well as a prior distribution of the class variables of a pixel and its 6 nearest 3-D neighbours....

  11. Interactive 3D multimedia content

    Cellary, Wojciech

    2012-01-01

    The book describes recent research results in the areas of modelling, creation, management and presentation of interactive 3D multimedia content. The book describes the current state of the art in the field and identifies the most important research and design issues. Consecutive chapters address these issues. These are: database modelling of 3D content, security in 3D environments, describing interactivity of content, searching content, visualization of search results, modelling mixed reality content, and efficient creation of interactive 3D content. Each chapter is illustrated with example a

  12. 3-D printers for libraries

    Griffey, Jason

    2014-01-01

    As the maker movement continues to grow and 3-D printers become more affordable, an expanding group of hobbyists is keen to explore this new technology. In the time-honored tradition of introducing new technologies, many libraries are considering purchasing a 3-D printer. Jason Griffey, an early enthusiast of 3-D printing, has researched the marketplace and seen several systems first hand at the Consumer Electronics Show. In this report he introduces readers to the 3-D printing marketplace, covering such topics asHow fused deposition modeling (FDM) printing workBasic terminology such as build

  13. Vulnerability mapping of groundwater contamination based on 3D lithostratigraphical models of porous aquifers.

    Ducci, Daniela; Sellerino, Mariangela

    2013-03-01

    The aim of this paper is to apply a methodology in order to reconstruct a lithostratigraphic 3D model of an aquifer so as to define some parameters involved in the evaluation of the aquifer vulnerability to contamination of porous aquifers. The DRASTIC, SINTACS and AVI methods have been applied to an alluvial coastal aquifer of southern Italy. The stratigraphic reconstruction has been obtained by interpolating stratigraphic data from more than one borehole per 2 km. The lithostratigraphic reconstruction of a 3D model has been applied and used for three-dimensional or two-dimensional representations. In the first two methods, the layers of the vadose zone and the aquifer media have been evaluated not only by the interpolation of the single boreholes and piezometers, but also by the 3D model, assigning the scores of the parameters of each layer of the 3D model. The comparison between the maps constructed from the weighted values in each borehole and the maps deriving from the attribution of the values of each layer of the 3D model, highlights that the second representation avoids or minimizes the "bullseye" effect linked to the presence of boreholes with higher or lower values. The study has demonstrated that it is possible to integrate a 3D lithostratigraphic model of an aquifer in the assessment of the parameters involved in the evaluation of the aquifer vulnerability to contamination by Point Count System methods. PMID:23391897

  14. Optimizing Seismic Monitoring Networks for EGS and Conventional Geothermal Projects

    Kraft, Toni; Herrmann, Marcus; Bethmann, Falko; Stefan, Wiemer

    2013-04-01

    location problem. Optimization for additional criteria (e.g., focal mechanism determination or installation costs) can be included. We consider a 3D seismic velocity model, an European ambient seismic noise model derived from high-resolution land-use data, and existing seismic stations in the vicinity of the geotechnical site. Additionally, we account for the attenuation of the seismic signal with travel time and ambient seismic noise with depth to be able to correctly deal with borehole station networks. Using this algorithm we are able to find the optimal geometry and size of the seismic monitoring network that meets the predefined application-oriented performance criteria. This talk will focus on optimal network geometries for deep geothermal projects of the EGS and hydrothermal type, and discuss the requirements for basic seismic surveillance and high-resolution reservoir monitoring and characterization.

  15. Testing long-period ground-motion simulations of scenario earthquakes using the Mw 7.2 El Mayor-Cucapah mainshock: Evaluation of finite-fault rupture characterization and 3D seismic velocity models

    Graves, Robert W.; Aagaard, Brad T.

    2011-01-01

    Using a suite of five hypothetical finite-fault rupture models, we test the ability of long-period (T>2.0 s) ground-motion simulations of scenario earthquakes to produce waveforms throughout southern California consistent with those recorded during the 4 April 2010 Mw 7.2 El Mayor-Cucapah earthquake. The hypothetical ruptures are generated using the methodology proposed by Graves and Pitarka (2010) and require, as inputs, only a general description of the fault location and geometry, event magnitude, and hypocenter, as would be done for a scenario event. For each rupture model, two Southern California Earthquake Center three-dimensional community seismic velocity models (CVM-4m and CVM-H62) are used, resulting in a total of 10 ground-motion simulations, which we compare with recorded ground motions. While the details of the motions vary across the simulations, the median levels match the observed peak ground velocities reasonably well, with the standard deviation of the residuals generally within 50% of the median. Simulations with the CVM-4m model yield somewhat lower variance than those with the CVM-H62 model. Both models tend to overpredict motions in the San Diego region and underpredict motions in the Mojave desert. Within the greater Los Angeles basin, the CVM-4m model generally matches the level of observed motions, whereas the CVM-H62 model tends to overpredict the motions, particularly in the southern portion of the basin. The variance in the peak velocity residuals is lowest for a rupture that has significant shallow slip (<5 km depth), whereas the variance in the residuals is greatest for ruptures with large asperities below 10 km depth. Overall, these results are encouraging and provide confidence in the predictive capabilities of the simulation methodology, while also suggesting some regions in which the seismic velocity models may need improvement.

  16. Improvement of 3D Scanner

    2003-01-01

    The disadvantage remaining in 3D scanning system and its reasons are discussed. A new host-and-slave structure with high speed image acquisition and processing system is proposed to quicken the image processing and improve the performance of 3D scanning system.

  17. 3D Printing for Bricks

    ECT Team, Purdue

    2015-01-01

    Building Bytes, by Brian Peters, is a project that uses desktop 3D printers to print bricks for architecture. Instead of using an expensive custom-made printer, it uses a normal standard 3D printer which is available for everyone and makes it more accessible and also easier for fabrication.

  18. Modular 3-D Transport model

    MT3D was first developed by Chunmiao Zheng in 1990 at S.S. Papadopulos & Associates, Inc. with partial support from the U.S. Environmental Protection Agency (USEPA). Starting in 1990, MT3D was released as a pubic domain code from the USEPA. Commercial versions with enhanced capab...

  19. Using 3D in Visualization

    Wood, Jo; Kirschenbauer, Sabine; Döllner, Jürgen;

    2005-01-01

    The notion of three-dimensionality is applied to five stages of the visualization pipeline. While 3D visulization is most often associated with the visual mapping and representation of data, this chapter also identifies its role in the management and assembly of data, and in the media used...... to display 3D imagery. The extra cartographic degree of freedom offered by using 3D is explored and offered as a motivation for employing 3D in visualization. The use of VR and the construction of virtual environments exploit navigational and behavioral realism, but become most usefil when combined...... with abstracted representations embedded in a 3D space. The interactions between development of geovisualization, the technology used to implement it and the theory surrounding cartographic representation are explored. The dominance of computing technologies, driven particularly by the gaming industry...

  20. Numerical modeling of wave processes in 3D fractured media

    Golubev V.; Petrov I.

    2014-01-01

    Seismic response from the cluster of vertical oriented cracks is simulated using grid-characteristic method on parallelepiped structured meshes. Synthetic seismograms and wave fields are calculated. The structure of the response including dependency on type of saturator (gas, fluid) is analyzed. Numerical experiments showed the effect of high-frequency daisy-chain wave’s generation from 3D periodic structures.

  1. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITHOUT TURB3D)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  2. PLOT3D/AMES, APOLLO UNIX VERSION USING GMR3D (WITH TURB3D)

    Buning, P.

    1994-01-01

    PLOT3D is an interactive graphics program designed to help scientists visualize computational fluid dynamics (CFD) grids and solutions. Today, supercomputers and CFD algorithms can provide scientists with simulations of such highly complex phenomena that obtaining an understanding of the simulations has become a major problem. Tools which help the scientist visualize the simulations can be of tremendous aid. PLOT3D/AMES offers more functions and features, and has been adapted for more types of computers than any other CFD graphics program. Version 3.6b+ is supported for five computers and graphic libraries. Using PLOT3D, CFD physicists can view their computational models from any angle, observing the physics of problems and the quality of solutions. As an aid in designing aircraft, for example, PLOT3D's interactive computer graphics can show vortices, temperature, reverse flow, pressure, and dozens of other characteristics of air flow during flight. As critical areas become obvious, they can easily be studied more closely using a finer grid. PLOT3D is part of a computational fluid dynamics software cycle. First, a program such as 3DGRAPE (ARC-12620) helps the scientist generate computational grids to model an object and its surrounding space. Once the grids have been designed and parameters such as the angle of attack, Mach number, and Reynolds number have been specified, a "flow-solver" program such as INS3D (ARC-11794 or COS-10019) solves the system of equations governing fluid flow, usually on a supercomputer. Grids sometimes have as many as two million points, and the "flow-solver" produces a solution file which contains density, x- y- and z-momentum, and stagnation energy for each grid point. With such a solution file and a grid file containing up to 50 grids as input, PLOT3D can calculate and graphically display any one of 74 functions, including shock waves, surface pressure, velocity vectors, and particle traces. PLOT3D's 74 functions are organized into

  3. Drilling, logging, and testing information from borehole UE-25 UZ{number_sign}16, Yucca Mountain, Nevada

    Thamir, F.; Thordarson, W.; Kume, J.; Rousseau, J. [Geological Survey, Denver, CO (United States). Yucca Mountain Project Branch; Long, R. [Dept. of Energy, Las Vegas, NV (United States); Cunningham, D.M. Jr. [Science Applications International Corp., Las Vegas, NV (United States)

    1998-09-01

    Borehole UE-25 UZ{number_sign}16 is the first of two boreholes that may be used to determine the subsurface structure at Yucca Mountain by using vertical seismic profiling. This report contains information collected while this borehole was being drilled, logged, and tested from May 27, 1992, to April 22, 1994. It does not contain the vertical seismic profiling data. This report is intended to be used as: (1) a reference for drilling similar boreholes in the same area, (2) a data source on this borehole, and (3) a reference for other information that is available from this borehole. The reference information includes drilling chronology, equipment, parameters, coring methods, penetration rates, completion information, drilling problems, and corrective actions. The data sources include lithology, fracture logs, a list of available borehole logs, and depths at which water was recorded. Other information is listed in an appendix that includes studies done after April 22, 1994.

  4. Drilling, logging, and testing information from borehole UE-25 UZ number-sign 16, Yucca Mountain, Nevada

    Borehole UE-25 UZ number-sign 16 is the first of two boreholes that may be used to determine the subsurface structure at Yucca Mountain by using vertical seismic profiling. This report contains information collected while this borehole was being drilled, logged, and tested from May 27, 1992, to April 22, 1994. It does not contain the vertical seismic profiling data. This report is intended to be used as: (1) a reference for drilling similar boreholes in the same area, (2) a data source on this borehole, and (3) a reference for other information that is available from this borehole. The reference information includes drilling chronology, equipment, parameters, coring methods, penetration rates, completion information, drilling problems, and corrective actions. The data sources include lithology, fracture logs, a list of available borehole logs, and depths at which water was recorded. Other information is listed in an appendix that includes studies done after April 22, 1994

  5. ADT-3D Tumor Detection Assistant in 3D

    Jaime Lazcano Bello

    2008-12-01

    Full Text Available The present document describes ADT-3D (Three-Dimensional Tumor Detector Assistant, a prototype application developed to assist doctors diagnose, detect and locate tumors in the brain by using CT scan. The reader may find on this document an introduction to tumor detection; ADT-3D main goals; development details; description of the product; motivation for its development; result’s study; and areas of applicability.

  6. Unassisted 3D camera calibration

    Atanassov, Kalin; Ramachandra, Vikas; Nash, James; Goma, Sergio R.

    2012-03-01

    With the rapid growth of 3D technology, 3D image capture has become a critical part of the 3D feature set on mobile phones. 3D image quality is affected by the scene geometry as well as on-the-device processing. An automatic 3D system usually assumes known camera poses accomplished by factory calibration using a special chart. In real life settings, pose parameters estimated by factory calibration can be negatively impacted by movements of the lens barrel due to shaking, focusing, or camera drop. If any of these factors displaces the optical axes of either or both cameras, vertical disparity might exceed the maximum tolerable margin and the 3D user may experience eye strain or headaches. To make 3D capture more practical, one needs to consider unassisted (on arbitrary scenes) calibration. In this paper, we propose an algorithm that relies on detection and matching of keypoints between left and right images. Frames containing erroneous matches, along with frames with insufficiently rich keypoint constellations, are detected and discarded. Roll, pitch yaw , and scale differences between left and right frames are then estimated. The algorithm performance is evaluated in terms of the remaining vertical disparity as compared to the maximum tolerable vertical disparity.

  7. The CIGEO Project - Examination of studies presented since 2009. Meeting of the Permanent Group of Experts for 'Wastes' on the 5 of February 2013. Volume 1 - Industrial program of waste management; Volume 2 - Release model for spent fuels; Volume 3 - Analysis of 3D seismicity

    The first volume reports the IRSN opinion on the industrial program of waste management which is associated with the Cigeo Project of deep storage of radioactive wastes. It discusses the inventory of wastes to be stored and the main hypotheses in terms of volume and of parcel typology, but also the organisation and provisional flows of parcel delivery. The second volume reports the IRSN opinion on the release operational model for spent fuels within the Cigeo Project. It gives an overview of the fuel management strategy within reactors, presents the concept of direct storage of spent fuels, and addresses the release by fuels under storage conditions. It notably discusses the instantaneous radionuclide release model and the matrix dissolution model. The third volume comments the results obtained during a campaign of 3D seismic data acquisition, and their analysis and interpretation with respect to the Cigeo geological environment and its geometry

  8. Installation of borehole seismometer for earthquake characteristics in deep geological environment

    Park, Dong Hee; Choi, Weon Hack; Cho, Sung Il; Chang, Chun Joong [KHNP CRI, Seoul (Korea, Republic of)

    2014-10-15

    Deep geological disposal is currently accepted as the most appropriate method for permanently removing spent nuclear fuel from the living sphere of humans. For implementation of deep geological disposal, we need to understand the geological changes that have taken place over the past 100,000 years, encompassing active faults, volcanic activity, elevation, ubsidence, which as yet have not been considered in assessing the site characteristics for general facilities, as well as to investigate and analyze the geological structures, fracture systems and seismic responses regarding deep geological environment about 500 meters or more underground. In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. Korea Hydro and Nuclear Power Co., Ltd. (KHNP) have installed the deep borehole earthquake observatory at depths of about 300 to 600 meters in order to study the seismic response characteristics in deep geological environment on June, 2014 in Andong area. This paper will show the status of deep borehole earthquake observatory and the results of background noise response characteristics of these deep borehole seismic data as a basic data analysis. We present here the status of deep borehole seismometer installation by KHNP. In order to basic data analysis for the borehole seismic observation data, this study shows the results of the orientation of seismometer and background noise characteristics by using a probability density function. Together with the ground motion data recorded by the borehole seismometers can be utilized as basic data for seismic response characteristics studies with regard to spent nuclear fuel disposal depth and as the input data for seismic hazard assessment that

  9. Installation of borehole seismometer for earthquake characteristics in deep geological environment

    Deep geological disposal is currently accepted as the most appropriate method for permanently removing spent nuclear fuel from the living sphere of humans. For implementation of deep geological disposal, we need to understand the geological changes that have taken place over the past 100,000 years, encompassing active faults, volcanic activity, elevation, ubsidence, which as yet have not been considered in assessing the site characteristics for general facilities, as well as to investigate and analyze the geological structures, fracture systems and seismic responses regarding deep geological environment about 500 meters or more underground. In regions with high seismic activity, such as Japan, the Western United States and Taiwan, borehole seismometers installed deep underground are used to monitor seismic activity during the course of seismic wave propagation at various depths and to study the stress changes due to earthquakes and analyze the connection to fault movements. Korea Hydro and Nuclear Power Co., Ltd. (KHNP) have installed the deep borehole earthquake observatory at depths of about 300 to 600 meters in order to study the seismic response characteristics in deep geological environment on June, 2014 in Andong area. This paper will show the status of deep borehole earthquake observatory and the results of background noise response characteristics of these deep borehole seismic data as a basic data analysis. We present here the status of deep borehole seismometer installation by KHNP. In order to basic data analysis for the borehole seismic observation data, this study shows the results of the orientation of seismometer and background noise characteristics by using a probability density function. Together with the ground motion data recorded by the borehole seismometers can be utilized as basic data for seismic response characteristics studies with regard to spent nuclear fuel disposal depth and as the input data for seismic hazard assessment that

  10. 5-axis 3D Printer

    Grutle, Øyvind Kallevik

    2015-01-01

    3D printers have in recent years become extremely popular. Even though 3D printing technology have existed since the late 1980's, it is now considered one of the most significant technological breakthroughs of the twenty-first century. Several different 3D printing processes have been invented during the years. But it is the fused deposition modeling (FDM) which was one of the first invented that is considered the most popular today. Even though the FDM process is the most popular, it still s...

  11. Handbook of 3D integration

    Garrou , Philip; Ramm , Peter

    2014-01-01

    Edited by key figures in 3D integration and written by top authors from high-tech companies and renowned research institutions, this book covers the intricate details of 3D process technology.As such, the main focus is on silicon via formation, bonding and debonding, thinning, via reveal and backside processing, both from a technological and a materials science perspective. The last part of the book is concerned with assessing and enhancing the reliability of the 3D integrated devices, which is a prerequisite for the large-scale implementation of this emerging technology. Invaluable reading fo

  12. Exploration of 3D Printing

    Lin, Zeyu

    2014-01-01

    3D printing technology is introduced and defined in this Thesis. Some methods of 3D printing are illustrated and their principles are explained with pictures. Most of the essential parts are presented with pictures and their effects are explained within the whole system. Problems on Up! Plus 3D printer are solved and a DIY product is made with this machine. The processes of making product are recorded and the items which need to be noticed during the process are the highlight in this th...

  13. Tuotekehitysprojekti: 3D-tulostin

    Pihlajamäki, Janne

    2011-01-01

    Opinnäytetyössä tutustuttiin 3D-tulostamisen teknologiaan. Työssä käytiin läpi 3D-tulostimesta tehty tuotekehitysprojekti. Sen lisäksi esiteltiin yleisellä tasolla tuotekehitysprosessi ja syntyneiden tulosten mahdollisia suojausmenetelmiä. Tavoitteena tässä työssä oli kehittää markkinoilta jo löytyvää kotitulostin-tasoista 3D-laiteteknologiaa lähemmäksi ammattilaistason ratkaisua. Tavoitteeseen pyrittiin keskittymällä parantamaan laitteella saavutettavaa tulostustarkkuutta ja -nopeutt...

  14. Color 3D Reverse Engineering

    2002-01-01

    This paper presents a principle and a method of col or 3D laser scanning measurement. Based on the fundamental monochrome 3D measureme nt study, color information capture, color texture mapping, coordinate computati on and other techniques are performed to achieve color 3D measurement. The syste m is designed and composed of a line laser light emitter, one color CCD camera, a motor-driven rotary filter, a circuit card and a computer. Two steps in captu ring object's images in the measurement process: Firs...

  15. 3-D neutron transport benchmarks

    A set of 3-D neutron transport benchmark problems proposed by the Osaka University to NEACRP in 1988 has been calculated by many participants and the corresponding results are summarized in this report. The results of Keff, control rod worth and region-averaged fluxes for the four proposed core models, calculated by using various 3-D transport codes are compared and discussed. The calculational methods used were: Monte Carlo, Discrete Ordinates (Sn), Spherical Harmonics (Pn), Nodal Transport and others. The solutions of the four core models are quite useful as benchmarks for checking the validity of 3-D neutron transport codes

  16. 3D on the internet

    Puntar, Matej

    2012-01-01

    The purpose of this thesis is the presentation of already established and new technologies of displaying 3D content in a web browser. The thesis begins with a short presentation of the history of 3D content available on the internet and its development together with advantages and disadvantages of individual technologies. The latter two are described in detail as well is their use and the differences among them. Special emphasis has been given to WebGL, the newest technology of 3D conte...

  17. 3D seismic survey in Honjo, Akita. Problems and struggles in acquisition and processing; Akitaken Honjo koku ni okeru sanjigen jishin tansa. Genba sagyo to data shori ni okeru mondaiten

    Imahori, S.; Kotera, Y.; Nakanishi, T. [Japan Energy Development Co. Ltd., Tokyo (Japan)

    1997-05-27

    Honjo mining area where investigations are conducted is hilly and has a complicated terrain with gas pipes buried in the ground just under the access road disabling the proper positioning of shock-generating large excavators or vibrators. Auger`s shallow hole shooting method is used in this survey to execute blastings at 639 points. In this method using charge depths of 4m, different from the conventional method using deeper charge depths (20-25m), surface waves prevail in the shot records giving rise to a new problem of removing them in the stage of data processing. The 2D filter that is a powerful tool in 2D data processing is not available in a 3D-survey where the tracing intervals are irregular in the shot records. In the effort of this time, a window length as a parameter in the direction of time is specified, and the F-X dip filtering method is employed in which any event that linearly continues beyond a certain number of traces in the said window is eliminated as a linear noise. It is recommended that the weighting function be changed in the direction of space since surface wave velocities are different at different locations. 1 fig., 1 tab.

  18. Vertical Cable Seismic Survey for SMS Exploration in Izena Cauldron, Okinawa-Trough

    Asakawa, E.; Murakami, F.; Tsukahara, H.; Mizohata, S.; Tara, K.

    2014-12-01

    The VCS survey is one of the reflection seismic methods. It uses hydrophone arrays vertically moored from the seafloor to record acoustic waves generated by seismic sources. Because the VCS is an efficient high-resolution 3D seismic survey method for a spatially-bounded area, we proposed it for the SMS survey tool development program started by Japanese government. In 2010, we manufactured the autonomous VCS data acquisition systems. Through several experimental surveys, our VCS is successfully completed. In 2011 and 2013, we carried out the two VCS surveys using GI gun and high-voltage sparker respectively in the Izena Cauldron, Okinawa Trough, which is one of the most promising SMS areas around Japan. Because seismic survey is not proven to be effective for SMS exploration, no seismic surveys have been conducted there so far. Our strategy for SMS exploration consists of two stages. In the first stage, we carried out VCS survey with the lower frequency GI gun (but higher compared to the convebtional oil/gas exploration) and explored deeper (up to 1,500m) structure to obtain the fault system of hydrothermal flow. Next, using a high frequency (about 1 kHz higher) and high-voltage sparker, we explored very shallow (up to 200m) part to delineate the very thin SMS deposits. These two VCS dataset have been processed with 3D Prestack Depth Migration. These results are consistent with geological information from the borehole drilled nearby and give useful information to SMS exploration.

  19. Magma Emplacement and the 3D Geometry of Igneous Bodies in Rift Basins: Insights from the Bornu Basin, Onshore NE Nigeria

    Suleiman, Adamu; Jackson, Christopher; Magee, Craig; Fraser, Alastair

    2016-04-01

    Recent studies of regional unconformities in the circum-South Atlantic tectonic plates have linked unconformity age to the timing of changes in the azimuth of oceanic fracture zones, caused by plate interactions during opening of the South Atlantic. This observation is significant, proposing that a plate boundary geodynamic processes are transmitted into and expressed in plate interiors. However, it is not yet clear if and how other geologic events, such as intra-plate magmatism, may be linked to changes in the oceanic fracture azimuthal geometry. Here we use 2D and 3D seismic reflection, geochemical, borehole datasets and outcrop observations from the Bornu Basin, one of several intra-continental rift basins located in NE Nigeria to constrain the 3D geometry of igneous bodies and magmatic emplacement processes. This allows us to link South Atlantic plate boundary geodynamics and magmatism in the surrounding continental rift basins. Seismic attributes, reflection intensity, relative acoustic impedance, were used to identify and map igneous intrusions. Saucer-shaped sills are the most common type of intrusion, although en-echelon sills, up to 1.4 km in length, were also identified. The 3D geometry of the sills reveals the detailed structural components like inner sill, inclined sheets and outer sill. A mapped bifurcating network of the sills suggests magma emplacement process through upward and outward propagation. Seismic-stratigraphic observations indicate that igneous activity occurred in the Early Cretaceous, Late Cretaceous and Paleogene corresponding to the timing of major azimuth changes observed in the Kane Oceanic fracture zone in the South Atlantic Ocean. Overall, our study, suggests a possible influence of plate boundary geodynamics on intra-plate magmatism as reflected in the link between the time of changes in the azimuth of oceanic fracture zones and magmatic emplacement observed in the tectono-stratigraphy of the intra-continental rift basins.

  20. Seismic 2D reflection processing and interpretation of shallow refraction data

    Posiva Oy takes care of the final disposal of spent nuclear fuel in Finland. In year 2001 Olkiluoto was selected for the site of final disposal. Currently construction of the underground research facility, ONKALO, is going on at the Olkiluoto site. The aim of this work was to use two-dimensional reflection seismic processing methods to refraction seismic data collected from the ONKALO area in year 2002, and to locate gently dipping reflectors from the stacked sections. Processing was done using mainly open source software Seismic Unix. After the processing, the most distinct two-dimensional reflectors were picked from seismic sections using visualization environment OpendTect. After picking the features from crossing lines were combined into three-dimensional surfaces. Special attention was given for the detection of possible faults and discontinuities. The surfaces were given coordinates and their orientation was adjusted using a geometric procedure, which corresponds roughly a 3D migration, transferred to 3D presentation utility and compared to available geological information. The advantage of this work is to be able to get three-dimensional reflection seismic results from existing data set at only processing costs. Survey lines are also partly located in ONKALO area where extensive surface seismic surveys may not be possible to perform. The applied processing method was successful in detecting the reflectors. Most significant steps were the refraction and residual statics, and deconvolution. Some distinct reflectors can be seen at times 20-200 ms (vertical depths 50-500 m). The signal gets noisier below 200 ms. Reflectors are best visible as coherent phase between the adjacent traces, but do not raise much above the surrounding noise level. Higher amount of traces to be stacked would emphasis the reflections and their continuity more. Reflectors picked on crossing lines match well to borehole observations (KR4, KR7, KR24 and KR38) of fracture zones, and get

  1. Heterodyne 3D ghost imaging

    Yang, Xu; Zhang, Yong; Yang, Chenghua; Xu, Lu; Wang, Qiang; Zhao, Yuan

    2016-06-01

    Conventional three dimensional (3D) ghost imaging measures range of target based on pulse fight time measurement method. Due to the limit of data acquisition system sampling rate, range resolution of the conventional 3D ghost imaging is usually low. In order to take off the effect of sampling rate to range resolution of 3D ghost imaging, a heterodyne 3D ghost imaging (HGI) system is presented in this study. The source of HGI is a continuous wave laser instead of pulse laser. Temporal correlation and spatial correlation of light are both utilized to obtain the range image of target. Through theory analysis and numerical simulations, it is demonstrated that HGI can obtain high range resolution image with low sampling rate.

  2. Conducting polymer 3D microelectrodes

    Sasso, Luigi; Vazquez, Patricia; Vedarethinam, Indumathi;

    2010-01-01

    Conducting polymer 3D microelectrodes have been fabricated for possible future neurological applications. A combination of micro-fabrication techniques and chemical polymerization methods has been used to create pillar electrodes in polyaniline and polypyrrole. The thin polymer films obtained...

  3. Main: TATCCAYMOTIFOSRAMY3D [PLACE

    Full Text Available TATCCAYMOTIFOSRAMY3D S000256 01-August-2006 (last modified) kehi TATCCAY motif found in rice (O. ... otif and G motif (see S000130) are responsible for sugar ... repression (Toyofuku et al. 1998); GATA; amylase; ...

  4. Combinatorial 3D Mechanical Metamaterials

    Coulais, Corentin; Teomy, Eial; de Reus, Koen; Shokef, Yair; van Hecke, Martin

    2015-03-01

    We present a class of elastic structures which exhibit 3D-folding motion. Our structures consist of cubic lattices of anisotropic unit cells that can be tiled in a complex combinatorial fashion. We design and 3d-print this complex ordered mechanism, in which we combine elastic hinges and defects to tailor the mechanics of the material. Finally, we use this large design space to encode smart functionalities such as surface patterning and multistability.

  5. 3D Face Appearance Model

    Lading, Brian; Larsen, Rasmus; Åström, Kalle

    2006-01-01

    We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}......We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}...

  6. 3D Face Apperance Model

    Lading, Brian; Larsen, Rasmus; Astrom, K

    2006-01-01

    We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations......We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations...

  7. AI 3D Cybug Gaming

    Ahmed, Zeeshan

    2010-01-01

    In this short paper I briefly discuss 3D war Game based on artificial intelligence concepts called AI WAR. Going in to the details, I present the importance of CAICL language and how this language is used in AI WAR. Moreover I also present a designed and implemented 3D War Cybug for AI WAR using CAICL and discus the implemented strategy to defeat its enemies during the game life.

  8. From 3D view to 3D print

    Dima, M.; Farisato, G.; Bergomi, M.; Viotto, V.; Magrin, D.; Greggio, D.; Farinato, J.; Marafatto, L.; Ragazzoni, R.; Piazza, D.

    2014-08-01

    In the last few years 3D printing is getting more and more popular and used in many fields going from manufacturing to industrial design, architecture, medical support and aerospace. 3D printing is an evolution of bi-dimensional printing, which allows to obtain a solid object from a 3D model, realized with a 3D modelling software. The final product is obtained using an additive process, in which successive layers of material are laid down one over the other. A 3D printer allows to realize, in a simple way, very complex shapes, which would be quite difficult to be produced with dedicated conventional facilities. Thanks to the fact that the 3D printing is obtained superposing one layer to the others, it doesn't need any particular work flow and it is sufficient to simply draw the model and send it to print. Many different kinds of 3D printers exist based on the technology and material used for layer deposition. A common material used by the toner is ABS plastics, which is a light and rigid thermoplastic polymer, whose peculiar mechanical properties make it diffusely used in several fields, like pipes production and cars interiors manufacturing. I used this technology to create a 1:1 scale model of the telescope which is the hardware core of the space small mission CHEOPS (CHaracterising ExOPlanets Satellite) by ESA, which aims to characterize EXOplanets via transits observations. The telescope has a Ritchey-Chrétien configuration with a 30cm aperture and the launch is foreseen in 2017. In this paper, I present the different phases for the realization of such a model, focusing onto pros and cons of this kind of technology. For example, because of the finite printable volume (10×10×12 inches in the x, y and z directions respectively), it has been necessary to split the largest parts of the instrument in smaller components to be then reassembled and post-processed. A further issue is the resolution of the printed material, which is expressed in terms of layers

  9. 3D model of the Bernese Part of the Swiss Molasse Basin: visualization of uncertainties in a 3D model

    Mock, Samuel; Allenbach, Robin; Reynolds, Lance; Wehrens, Philip; Kurmann-Matzenauer, Eva; Kuhn, Pascal; Michael, Salomè; Di Tommaso, Gennaro; Herwegh, Marco

    2016-04-01

    The Swiss Molasse Basin comprises the western and central part of the North Alpine Foreland Basin. In recent years it has come under closer scrutiny due to its promising geopotentials such as geothermal energy and CO2 sequestration. In order to adress these topics good knowledge of the subsurface is a key prerequisite. For that matter, geological 3D models serve as valuable tools. In collaboration with the Swiss Geological Survey (swisstopo) and as part of the project GeoMol CH, a geological 3D model of the Swiss Molasse Basin in the Canton of Bern has been built. The model covers an area of 1810 km2and reaches depth of up to 6.7 km. It comprises 10 major Cenozoic and Mesozoic units and numerous faults. The 3D model is mainly based on 2D seismic data complemented by information from few deep wells. Additionally, data from geological maps and profiles were used for refinement at shallow depths. In total, 1163 km of reflection seismic data, along 77 seismic lines, have been interpreted by different authors with respect to stratigraphy and structures. Both, horizons and faults, have been interpreted in 2D and modelled in 3D using IHS's Kingdom Suite and Midland Valley's MOVE software packages, respectively. Given the variable degree of subsurface information available, each 3D model is subject of uncertainty. With the primary input data coming from interpretation of reflection seismic data, a variety of uncertainties comes into play. Some of them are difficult to address (e.g. author's style of interpretation) while others can be quantified (e.g. mis-tie correction, well-tie). An important source of uncertainties is the quality of seismic data; this affects the traceability and lateral continuation of seismic reflectors. By defining quality classes we can semi-quantify this source of uncertainty. In order to visualize the quality and density of the input data in a meaningful way, we introduce quality-weighted data density maps. In combination with the geological 3D

  10. YouDash3D: exploring stereoscopic 3D gaming for 3D movie theaters

    Schild, Jonas; Seele, Sven; Masuch, Maic

    2012-03-01

    Along with the success of the digitally revived stereoscopic cinema, events beyond 3D movies become attractive for movie theater operators, i.e. interactive 3D games. In this paper, we present a case that explores possible challenges and solutions for interactive 3D games to be played by a movie theater audience. We analyze the setting and showcase current issues related to lighting and interaction. Our second focus is to provide gameplay mechanics that make special use of stereoscopy, especially depth-based game design. Based on these results, we present YouDash3D, a game prototype that explores public stereoscopic gameplay in a reduced kiosk setup. It features live 3D HD video stream of a professional stereo camera rig rendered in a real-time game scene. We use the effect to place the stereoscopic effigies of players into the digital game. The game showcases how stereoscopic vision can provide for a novel depth-based game mechanic. Projected trigger zones and distributed clusters of the audience video allow for easy adaptation to larger audiences and 3D movie theater gaming.

  11. Remote 3D Medical Consultation

    Welch, Greg; Sonnenwald, Diane H.; Fuchs, Henry; Cairns, Bruce; Mayer-Patel, Ketan; Yang, Ruigang; State, Andrei; Towles, Herman; Ilie, Adrian; Krishnan, Srinivas; Söderholm, Hanna M.

    Two-dimensional (2D) video-based telemedical consultation has been explored widely in the past 15-20 years. Two issues that seem to arise in most relevant case studies are the difficulty associated with obtaining the desired 2D camera views, and poor depth perception. To address these problems we are exploring the use of a small array of cameras to synthesize a spatially continuous range of dynamic three-dimensional (3D) views of a remote environment and events. The 3D views can be sent across wired or wireless networks to remote viewers with fixed displays or mobile devices such as a personal digital assistant (PDA). The viewpoints could be specified manually or automatically via user head or PDA tracking, giving the remote viewer virtual head- or hand-slaved (PDA-based) remote cameras for mono or stereo viewing. We call this idea remote 3D medical consultation (3DMC). In this article we motivate and explain the vision for 3D medical consultation; we describe the relevant computer vision/graphics, display, and networking research; we present a proof-of-concept prototype system; and we present some early experimental results supporting the general hypothesis that 3D remote medical consultation could offer benefits over conventional 2D televideo.

  12. Materialedreven 3d digital formgivning

    Hansen, Flemming Tvede

    2010-01-01

    Formålet med forskningsprojektet er for det første at understøtte keramikeren i at arbejde eksperimenterende med digital formgivning, og for det andet at bidrage til en tværfaglig diskurs om brugen af digital formgivning. Forskningsprojektet fokuserer på 3d formgivning og derved på 3d digital...... formgivning og Rapid Prototyping (RP). RP er en fællesbetegnelse for en række af de teknikker, der muliggør at overføre den digitale form til 3d fysisk form. Forskningsprojektet koncentrerer sig om to overordnede forskningsspørgsmål. Det første handler om, hvordan viden og erfaring indenfor det keramiske...... fagområde kan blive udnyttet i forhold til 3d digital formgivning. Det andet handler om, hvad en sådan tilgang kan bidrage med, og hvordan den kan blive udnyttet i et dynamisk samspil med det keramiske materiale i formgivningen af 3d keramiske artefakter. Materialedreven formgivning er karakteriseret af en...

  13. Novel 3D media technologies

    Dagiuklas, Tasos

    2015-01-01

    This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The contributions are based on the results of the FP7 European Project ROMEO, which focuses on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the future Internet. The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of consistent video quality to fixed and mobile users. ROMEO will present hybrid networking solutions that combine the DVB-T2 and DVB-NGH broadcas...

  14. 3D future internet media

    Dagiuklas, Tasos

    2014-01-01

    This book describes recent innovations in 3D media and technologies, with coverage of 3D media capturing, processing, encoding, and adaptation, networking aspects for 3D Media, and quality of user experience (QoE). The main contributions are based on the results of the FP7 European Projects ROMEO, which focus on new methods for the compression and delivery of 3D multi-view video and spatial audio, as well as the optimization of networking and compression jointly across the Future Internet (www.ict-romeo.eu). The delivery of 3D media to individual users remains a highly challenging problem due to the large amount of data involved, diverse network characteristics and user terminal requirements, as well as the user’s context such as their preferences and location. As the number of visual views increases, current systems will struggle to meet the demanding requirements in terms of delivery of constant video quality to both fixed and mobile users. ROMEO will design and develop hybrid-networking solutions that co...

  15. Geophysical borehole logging

    Most of the available literature on geophysical borehole logging refers to studies carried out in sedimentary rocks. It is only in recent years that any great interest has been shown in geophysical logging in boreholes in metamorphic and igneous rocks following the development of research programmes associated with geothermal energy and nuclear waste disposal. This report is concerned with the programme of geophysical logging carried out on the three deep boreholes at Altnabreac, Caithness, to examine the effectiveness of these methods in crystalline rock. Of particular importance is the assessment of the performance of the various geophysical sondes run in the boreholes in relation to the rock mass properties. The geophysical data can be used to provide additional in-situ information on the geological, hydrogeological and engineering properties of the rock mass. Fracturing and weathering in the rock mass have a considerable effect on both the design parameters for an engineering structure and the flow of water through the rock mass; hence, the relation between the geophysical properties and the degree of fracturing and weathering is examined in some detail. (author)

  16. A gravimetric 3D global inversion for cavity detection

    Camacho, A.G.; Vieira, R.; Montesinos, F.G. (Inst. de Astronomia y Geodesia, Madrid (Spain). Faculty de CC. Matematicas); Cuellar, V. (Lab. de Geotecnia del Centro de Estudios y Experimentacion de Obras Publicas, Madrid (Spain))

    1994-02-01

    A gravimetric survey, covering a site 200 m square, was carried out in order to locate karstic cavities. After eliminating the regional trend using a polynomial fit, the residual is modeled by least-squares prediction. Correlated signals for several wavelengths are detected. The inversion of these anomalies is performed by a global 3D adjustment using spherical bodies as models. The adjustment is repeated in order to obtain a stable configuration. The results show the probable presence of a system of cavities and galleries. Data collected from boreholes and the subsequent appearance of sink-holes are consistent with the results.

  17. 井约束下的三维地震波阻抗反演识别构造煤发育区%Tectonoclastic Coal Developed Area Identification through Well Constrained 3D Seismic Wave Impedance Inversion

    金学良

    2015-01-01

    煤与瓦斯突出是影响煤矿安全生产的重要地质因素,而“构造煤”的发育是煤与瓦斯突出的一个必要条件。如何识别“构造煤”分布范围对于采取煤与瓦斯突出防治措施尤为重要。淮北芦岭煤矿Ⅲ102、Ⅲ106采区构造发育,煤层破坏严重,煤与瓦斯突出的危害较大。该区的测井资料表明,其构造煤在波速、密度方面与原生结构煤均有较大差异,因此波阻抗有利于确定构造煤的分布范围。通过对研究区的地震数据进行井约束下的波阻抗反演,得到初始波阻抗体,并对其低频信息进行多次迭代反演,得到最终反演波阻抗体。通过对比解释研究区过井波阻抗反演时间剖面、8煤层反射波能量最大值及±10ms时窗的阻抗幅均方根平面图,有效划分出区内构造煤、原生结构煤及其过渡区。%Coal and gas outburst is an important geological factor to impact coalmine safety in production, while the development of tec⁃tonoclastic coal is a prerequisite in coal and gas outburst. Thus how to identify tectonoclastic coal distribution range is particularly im⁃portant in coal and gas outburst controlling measures adoption. Structures are well developed in winning districts Nos. III 102 and III 106 of Luling coalmine in Huaibei caused coal seams seriously destructed and coal and gas outburst hazards. The well logging data in the area have shown that tectonoclastic coal and primary structure coal are different on aspects of wave velocity and density, so the wave impedance is propitious to determine tectonoclastic coal distribution range. Through study area seismic data well constrained wave impedance inversion, obtained initial wave impedance cube, then carried out multiple iterative inversions on its low frequency in⁃formation, finally obtained inversion wave impedance cube. Through comparative interpretation of study area wave impedance inversion time section passing

  18. Cleaning of boreholes

    In terms of long-term safety it is a risk that the boreholes can eventually function as short-circuits between the repository and ground surface. Therefore sealing of investigation boreholes is an important issue for the long- term safety of high-level nuclear waste repositories. In order to seal a borehole properly, the conditions of the borehole have to meet certain predetermined requirements. One of the requirements is that no instruments or materials endangering the plugging operation or the long-term function of the sealing materials, are allowed to be left in the borehole. Sometimes drilling equipment will be left in the hole or it cannot be recovered from the hole with the given constraints of time, cost and resources in spite of attempts. Additionally various measurements may be carried out in the holes after the drilling has been completed and measuring devices may get stuck in holes. Consequently cleaning of the borehole is carried out as an essential activity before sealing can be implemented. There are two common reasons identified for the drill strings to get stuck in holes. First the drill string may get stuck due to acute drilling problems. The second case is where rods are left as casing in a hole either based on the structure of the upper part of the hole or in order to support the hole. To remove the drilling or measuring equipment lost in a borehole, special techniques and professional skill must be applied. Removing measuring equipment from a hole is often demanding and time consuming work. A vital part of the cleaning operation is planning the work in advance. In order to make the plan and to select the suitable methods it is important to know the condition of the stuck material. It is also important to know the exact depth where the equipment are stuck and to have an estimate of the reasons why they have got stuck. It is also very important to know the correct dimensions of the equipment or drill string before commencing the cleaning work

  19. Modification of 3D milling machine to 3D printer

    Halamíček, Lukáš

    2015-01-01

    Tato práce se zabývá přestavbou gravírovací frézky na 3D tiskárnu. V první části se práce zabývá možnými technologiemi 3D tisku a možností jejich využití u přestavby. Dále jsou popsány a vybrány vhodné součásti pro přestavbu. V další části je realizováno řízení ohřevu podložky, trysky a řízení posuvu drátu pomocí softwaru TwinCat od společnosti Beckhoff na průmyslovém počítači. Výsledkem práce by měla být oživená 3D tiskárna. This thesis deals with rebuilding of engraving machine to 3D pri...

  20. 3D Imager and Method for 3D imaging

    Kumar, P.; Staszewski, R.; Charbon, E.

    2013-01-01

    3D imager comprising at least one pixel, each pixel comprising a photodetectorfor detecting photon incidence and a time-to-digital converter system configured for referencing said photon incidence to a reference clock, and further comprising a reference clock generator provided for generating the re

  1. Validation of TRAB-3D

    TRAB-3D is a reactor dynamics code with three-dimensional neutronics coupled to core and circuit thermal-hydraulics. The code, entirely developed at VTT, can be used in transient and accident analyses of boiling (BWR) and pressurized water (PWR) reactors with rectangular fuel bundle geometry. The validation history of TRAB-3D includes calculation of international benchmark exercises, as well as comparisons with measured data from real plant transients. The most recent validation case is a load rejection test performed at the Olkiluoto 1 nuclear power plant in 1998 in connection with the power uprating project. The fact that there is local power measurement data available from this test makes it a suitable case for three-dimensional core model validation. The agreement between the results of the TRAB-3D calculation and the measurements is very good. (orig.)

  2. Crowded Field 3D Spectroscopy

    Becker, T; Roth, M M; Becker, Thomas; Fabrika, Sergei; Roth, Martin M.

    2003-01-01

    The quantitative spectroscopy of stellar objects in complex environments is mainly limited by the ability of separating the object from the background. Standard slit spectroscopy, restricting the field of view to one dimension, is obviously not the proper technique in general. The emerging Integral Field (3D) technique with spatially resolved spectra of a two-dimensional field of view provides a great potential for applying advanced subtraction methods. In this paper an image reconstruction algorithm to separate point sources and a smooth background is applied to 3D data. Several performance tests demonstrate the photometric quality of the method. The algorithm is applied to real 3D observations of a sample Planetary Nebula in M31, whose spectrum is contaminated by the bright and complex galaxy background. The ability of separating sources is also studied in a crowded stellar field in M33.

  3. Markerless 3D Face Tracking

    Walder, Christian; Breidt, Martin; Bulthoff, Heinrich;

    2009-01-01

    We present a novel algorithm for the markerless tracking of deforming surfaces such as faces. We acquire a sequence of 3D scans along with color images at 40Hz. The data is then represented by implicit surface and color functions, using a novel partition-of-unity type method of efficiently...... combining local regressors using nearest neighbor searches. Both these functions act on the 4D space of 3D plus time, and use temporal information to handle the noise in individual scans. After interactive registration of a template mesh to the first frame, it is then automatically deformed to track...... the scanned surface, using the variation of both shape and color as features in a dynamic energy minimization problem. Our prototype system yields high-quality animated 3D models in correspondence, at a rate of approximately twenty seconds per timestep. Tracking results for faces and other objects...

  4. 3D vector flow imaging

    Pihl, Michael Johannes

    The main purpose of this PhD project is to develop an ultrasonic method for 3D vector flow imaging. The motivation is to advance the field of velocity estimation in ultrasound, which plays an important role in the clinic. The velocity of blood has components in all three spatial dimensions, yet...... conventional methods can estimate only the axial component. Several approaches for 3D vector velocity estimation have been suggested, but none of these methods have so far produced convincing in vivo results nor have they been adopted by commercial manufacturers. The basis for this project is the Transverse...... on the TO fields are suggested. They can be used to optimize the TO method. In the third part, a TO method for 3D vector velocity estimation is proposed. It employs a 2D phased array transducer and decouples the velocity estimation into three velocity components, which are estimated simultaneously based on 5...

  5. 3D-grafiikkamoottori mobiililaitteille

    Vahlman, Lauri

    2014-01-01

    Tässä insinöörityössä käydään läpi mobiililaitteille suunnatun yksinkertaisen 3D-grafiikkamoottorin suunnittelu ja toteutus käyttäen OpenGL ES -rajapintaa. Työssä esitellään grafiikkamoottorin toteutuksessa käytettyjä tekniikoita sekä tutustutaan moottorin rakenteeseen ja toteutuksellisiin yksityiskohtiin. Työn alkupuolella tutustutaan myös modernin 3D-grafiikan yleisiin periaatteisiin ja toimintaan sekä käydään läpi 3D-grafiikkaan liittyviä suorituskykyongelmia. Työn loppupuolella esitel...

  6. High-resolution reflection seismic imaging of the upper crust at Laxemar, southeastern Sweden

    Bergman, B.; Juhlin, C.; Palm, H.

    2002-09-01

    A major cost in exploring the upper 1-2 km of crystalline crust with reflection seismics is the drilling required for explosive sources. By reducing the charge size to a minimum, shallow inexpensive shotholes can be drilled with handheld equipment. Here, we present results from a full-scale test using small charges for high-resolution seismic surveying over a nuclear waste disposal study site (not an actual site). Two 2-2.5-km-long crossing profiles were acquired in December 1999 with 10-m shot and geophone spacing in the Laxemar area, near Oskarshamn in southeastern Sweden. After standard processing, including dip moveout (DMO), several subhorizontal to moderately dipping reflections are imaged. Many of the dipping ones can be correlated to fracture zones observed in a ca. 1700-m-deep borehole where the profiles cross and/or to fracture zones mapped on the surface. The imaged fracture zones form a complex 3D pattern illustrating the necessity of having 3D control before interpreting seismic reflection data. Analyses of sonic and density logs from the borehole show that greenstones have significantly higher impedances than the more dominant granite found in the borehole (granite/greenstone reflection coefficient is +0.065). These greenstones may contribute to the reflectivity when associated with fracture zones. In some cases, where they are present as larger subhorizontal lenses, they may be the dominant source of reflectivity. A set of north-dipping (10°) reflectors at 3-3.5-km depth can be correlated to a similar set observed below the island of Ävrö about 3 km to the east.

  7. 3D Computations and Experiments

    Couch, R; Faux, D; Goto, D; Nikkel, D

    2004-04-05

    This project consists of two activities. Task A, Simulations and Measurements, combines all the material model development and associated numerical work with the materials-oriented experimental activities. The goal of this effort is to provide an improved understanding of dynamic material properties and to provide accurate numerical representations of those properties for use in analysis codes. Task B, ALE3D Development, involves general development activities in the ALE3D code with the focus of improving simulation capabilities for problems of mutual interest to DoD and DOE. Emphasis is on problems involving multi-phase flow, blast loading of structures and system safety/vulnerability studies.

  8. 3D proton beam micromachining

    Focused high energy ion beam micromachining is the newest of the micromachining techniques. There are about 50 scanning proton microprobe facilities worldwide, but so far only few of them showed activity in this promising field. High energy ion beam micromachining using a direct-write scanning MeV ion beam is capable of producing 3D microstructures and components with well defined lateral and depth geometry. The technique has high potential in the manufacture of 3D molds, stamps, and masks for X-ray lithography (LIGA), and also in the rapid prototyping of microcomponents either for research purposes or for components testing prior to batch production. (R.P.)

  9. Making Inexpensive 3-D Models

    Manos, Harry

    2016-01-01

    Visual aids are important to student learning, and they help make the teacher's job easier. Keeping with the "TPT" theme of "The Art, Craft, and Science of Physics Teaching," the purpose of this article is to show how teachers, lacking equipment and funds, can construct a durable 3-D model reference frame and a model gravity…

  10. 3D Face Appearance Model

    Lading, Brian; Larsen, Rasmus; Åström, Kalle

    2006-01-01

    We build a 3d face shape model, including inter- and intra-shape variations, derive the analytical jacobian of its resulting 2d rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations.}

  11. 3D Face Apperance Model

    Lading, Brian; Larsen, Rasmus; Astrom, K

    2006-01-01

    We build a 3D face shape model, including inter- and intra-shape variations, derive the analytical Jacobian of its resulting 2D rendered image, and show example of its fitting performance with light, pose, id, expression and texture variations

  12. 3D Printing: Exploring Capabilities

    Samuels, Kyle; Flowers, Jim

    2015-01-01

    As 3D printers become more affordable, schools are using them in increasing numbers. They fit well with the emphasis on product design in technology and engineering education, allowing students to create high-fidelity physical models to see and test different iterations in their product designs. They may also help students to "think in three…

  13. 3D terahertz beam profiling

    Pedersen, Pernille Klarskov; Strikwerda, Andrew; Wang, Tianwu;

    2013-01-01

    We present a characterization of THz beams generated in both a two-color air plasma and in a LiNbO3 crystal. Using a commercial THz camera, we record intensity images as a function of distance through the beam waist, from which we extract 2D beam profiles and visualize our measurements into 3D beam...

  14. Viewing galaxies in 3D

    Krajnović, Davor

    2016-01-01

    Thanks to a technique that reveals galaxies in 3D, astronomers can now show that many galaxies have been wrongly classified. Davor Krajnovi\\'c argues that the classification scheme proposed 85 years ago by Edwin Hubble now needs to be revised.

  15. Ice-Borehole Probe

    Behar, Alberto; Carsey, Frank; Lane, Arthur; Engelhardt, Herman

    2006-01-01

    An instrumentation system has been developed for studying interactions between a glacier or ice sheet and the underlying rock and/or soil. Prior borehole imaging systems have been used in well-drilling and mineral-exploration applications and for studying relatively thin valley glaciers, but have not been used for studying thick ice sheets like those of Antarctica. The system includes a cylindrical imaging probe that is lowered into a hole that has been bored through the ice to the ice/bedrock interface by use of an established hot-water-jet technique. The images acquired by the cameras yield information on the movement of the ice relative to the bedrock and on visible features of the lower structure of the ice sheet, including ice layers formed at different times, bubbles, and mineralogical inclusions. At the time of reporting the information for this article, the system was just deployed in two boreholes on the Amery ice shelf in East Antarctica and after successful 2000 2001 deployments in 4 boreholes at Ice Stream C, West Antarctica, and in 2002 at Black Rapids Glacier, Alaska. The probe is designed to operate at temperatures from 40 to +40 C and to withstand the cold, wet, high-pressure [130-atm (13.20-MPa)] environment at the bottom of a water-filled borehole in ice as deep as 1.6 km. A current version is being outfitted to service 2.4-km-deep boreholes at the Rutford Ice Stream in West Antarctica. The probe (see figure) contains a sidelooking charge-coupled-device (CCD) camera that generates both a real-time analog video signal and a sequence of still-image data, and contains a digital videotape recorder. The probe also contains a downward-looking CCD analog video camera, plus halogen lamps to illuminate the fields of view of both cameras. The analog video outputs of the cameras are converted to optical signals that are transmitted to a surface station via optical fibers in a cable. Electric power is supplied to the probe through wires in the cable at a