Sample records for hydraulic borehole seismic

  1. Development of a hydraulic borehole seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, R.P.


    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.

  2. Hydraulically controlled discrete sampling from open boreholes (United States)

    Harte, Philip T.


    Groundwater sampling from open boreholes in fractured-rock aquifers is particularly challenging because of mixing and dilution of fluid within the borehole from multiple fractures. This note presents an alternative to traditional sampling in open boreholes with packer assemblies. The alternative system called ZONFLO (zonal flow) is based on hydraulic control of borehole flow conditions. Fluid from discrete fractures zones are hydraulically isolated allowing for the collection of representative samples. In rough-faced open boreholes and formations with less competent rock, hydraulic containment may offer an attractive alternative to physical containment with packers. Preliminary test results indicate a discrete zone can be effectively hydraulically isolated from other zones within a borehole for the purpose of groundwater sampling using this new method.

  3. Borehole prototype for seismic high-resolution exploration (United States)

    Giese, Rüdiger; Jaksch, Katrin; Krauß, Felix; Krüger, Kay; Groh, Marco; Jurczyk, Andreas


    Target reservoirs for the exploitation of hydrocarbons or hot water for geothermal energy supply can comprise small layered structures, for instance thin layers or faults. The resolution of 2D and 3D surface seismic methods is often not sufficient to determine and locate these structures. Borehole seismic methods like vertical seismic profiling (VSP) and seismic while drilling (SWD) use either receivers or sources within the borehole. Thus, the distance to the target horizon is reduced and higher resolution images of the geological structures can be achieved. Even these methods are limited in their resolution capabilities with increasing target depth. To localize structures more accuracy methods with higher resolution in the range of meters are necessary. The project SPWD -- Seismic Prediction While Drilling aims at s the development of a borehole prototype which combines seismic sources and receivers in one device to improve the seismic resolution. Within SPWD such a prototype has been designed, manufactured and tested. The SPWD-wireline prototype is divided into three main parts. The upper section comprises the electronic unit. The middle section includes the upper receiver, the upper clamping unit as well as the source unit and the lower clamping unit. The lower section consists of the lower receiver unit and the hydraulic unit. The total length of the prototype is nearly seven meters and its weight is about 750 kg. For focusing the seismic waves in predefined directions of the borehole axis the method of phased array is used. The source unit is equipped with four magnetostrictive vibrators. Each can be controlled independently to get a common wave front in the desired direction of exploration. Source signal frequencies up to 5000 Hz are used, which allows resolutions up to one meter. In May and September 2013 field tests with the SPWD-wireline prototype have been carried out at the KTB Deep Crustal Lab in Windischeschenbach (Bavaria). The aim was to proof the

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  6. Development of a magnetostrictive borehole seismic source

    Energy Technology Data Exchange (ETDEWEB)

    Cutler, R.P.; Sleefe, G.E.; Keefe, R.G.


    A magnetostrictive borehole seismic source was developed for use in high resolution crosswell surveys in environmental applications. The source is a clamped, vertical-shear, swept frequency, reaction-mass shaker design consisting of a spring pre-loaded magnetostrictive rod with permanent magnet bias, drive coils to induce an alternating magnetic field, and an integral tungsten reaction mass. The actuator was tested extensively in the laboratory. It was then incorporated into an easily deployable clamped downhole tool capable of operating on a standard 7 conductor wireline in borehole environments to 10,000{degrees} deep and 100{degrees}C. It can be used in either PVC or steel cased wells and the wells can be dry or fluid filled. It has a usable frequency spectrum of {approx} 150 to 2000 Hz. The finished tool was successfully demonstrated in a crosswell test at a shallow environmental site at Hanford, Washington. The source transmitted signals with a S/N ratio of 10-15 dB from 150-720 Hz between wells spaced 239 feet apart in unconsolidated gravel. The source was also tested successfully in rock at an oil field test site, transmitting signals with a S/N ratio of 5-15 dB over the full sweep spectrum from 150-2000 Hz between wells spaced 282 feet apart. And it was used successfully on an 11,000{degrees} wireline at a depth of 4550{degrees}. Recommendations for follow-on work include improvements to the clamp, incorporation of a higher sample rate force feedback controller, and increases in the force output of the tool.

  7. Borehole depth and regolith aquifer hydraulic characteristics of ...

    African Journals Online (AJOL)


    Borehole depth and regolith aquifer hydraulic characteristics of bedrock types in Kano area, Northern. Nigeria. Bala Abdullahi Emmanuel1, Eduvie Obada Martins2, and Byami Jolly1. 1Department of Geology, Ahmadu Bello University, Zaria, Kaduna State, Nigeria. 2National Water Resources Institute, P. M. B. 2309 Kaduna, ...

  8. Seismic investigations for high resolution exploration ahead and around boreholes (United States)

    Jaksch, Katrin; Giese, Ruediger; Kopf, Matthias


    Deep reservoirs usually will be explored with a surface seismic survey often in combination with borehole seismic measurements like VSP or SWD which can improve the velocity model of the underground. Reservoirs especially in geothermal fields are often characterized by small-scale structures. Additionally, with depth the need for exploration methods with a high resolution increases because standard methods like borehole seismic measurements cannot improve their resolution with depth. To localize structures with more accuracy methods with higher resolution in the range of meters are necessary. Within the project SPWD - Seismic Prediction While Drilling a new exploration method will be developed. With an implementation of seismic sources and receivers in one device an exploration method ahead and around the borehole will be enabled. Also, a high resolution independent from the depth will be achieved. Therefore active and powerful seismic sources are necessary to reach an acceptable penetration depth. Step by step seismic borehole devices were developed, which can be used under different conditions. Every borehole device contains four seismic sources and several three-component geophones. A small distance between actuators and geophones allows detecting also the high frequency content of the wave field reflected at geological structures. Also, exploration with a high resolution is possible. A first borehole device was developed for basic conditions in horizontal boreholes without special terms to temperature or pressure. In a mine first methodical measurements for the initiated wave field were performed. Therefor an existing seismic test area at the research and education mine of the TU Bergakademie Freiberg was extended with boreholes. In the seismic test area, consisting of a dense geophone array with three-component geophone anchors, two horizontal and one vertical borehole was drilled. To achieve a radiation pattern in predefined directions by constructive

  9. Hydromechanical analyses of the hydraulic stimulation of borehole Basel 1 (United States)

    Ortiz R., Adrián E.; Renner, Jörg; Jung, Reinhard


    We analysed the response of the underground penetrated by borehole Basel 1 to two pumping sequences, a pre-stimulation test (flow rate up to 10 L min-1) followed by a step-up stimulation (starting from 10 L min-1 up to 3380 L min-1), performed to generate a heat exchanger at about 5 km depth. Throughout the test sequences an increase in flow rate resulted in an increase in injection pressure. Yet, sudden pressure drops (≲0.1 MPa) as well as a continuous decrease in pressure occurred at constant flow rates above 100 L min-1. Analysis of the pre-stimulation record strongly suggests the existence of a vertical fracture prior to stimulation. We focused on two contrasting scenarios in fracture height and normalized fracture conductivity out of the range of possible geometrical characteristics of this pre-existent fracture as constrained by numerical modelling. Independent of chosen scenario, the initially modest pressure increase can only be modelled by hydraulic properties that change with fluid-pressure. The spatio-temporal characteristics of the pressure distributions differ significantly for the two scenarios; the 'formation linear flow'-like pattern found for the scenario with the larger fracture height of 100 m matches geometrically better with the oblate seismic cloud than the 'radial flow'-like pattern found for the smaller fracture height of 10 m. It is problematic to explain the drops in pressure observed at constant flow rate by lateral or vertical extension of the pre-existent vertical fracture in classical tensile hydrofracturing mode considering the persistent increase in pressure with every step-up in flow rate throughout the entire stimulation and the lack of reproducible and distinct instantaneous shut-in pressures. We suggest shearing and wing-extension of the pre-existent fracture(s) as an alternative mechanism since this mechanism (a) is consistent with the absence of a distinct breakdown in pressure, (b) can be initiated at fluid pressures below

  10. Hydraulic impulse generator and frequency sweep mechanism for borehole applications (United States)

    Kolle, Jack J.; Marvin, Mark H.; Theimer, Kenneth J.


    This invention discloses a valve that generates a hydraulic negative pressure pulse and a frequency modulator for the creation of a powerful, broadband swept impulse seismic signal at the drill bit during drilling operations. The signal can be received at monitoring points on the surface or underground locations using geophones. The time required for the seismic signal to travel from the source to the receiver directly and via reflections is used to calculate seismic velocity and other formation properties near the source and between the source and receiver. This information can be used for vertical seismic profiling of formations drilled, to check the location of the bit, or to detect the presence of abnormal pore pressure ahead of the bit. The hydraulic negative pressure pulse can also be used to enhance drilling and production of wells.

  11. A Hydraulic Stress Measurement System for Deep Borehole Investigations (United States)

    Ask, Maria; Ask, Daniel; Cornet, Francois; Nilsson, Tommy


    Luleå University of Technology (LTU) is developing and building a wire-line system for hydraulic rock stress measurements, with funding from the Swedish Research Council and Luleå University of Technology. In this project, LTU is collaborating with University of Strasbourg and Geosigma AB. The stress state influences drilling and drillability, as well as rock mass stability and permeability. Therefore, knowledge about the state of in-situ stress (stress magnitudes, and orientations) and its spatial variation with depth is essential for many underground rock engineering projects, for example for underground storage of hazardous material (e.g. nuclear waste, carbon dioxide), deep geothermal exploration, and underground infrastructure (e.g. tunneling, hydropower dams). The system is designed to conduct hydraulic stress testing in slim boreholes. There are three types of test methods: (1) hydraulic fracturing, (2) sleeve fracturing and (3) hydraulic testing of pre-existing fractures. These are robust methods for determining in situ stresses from boreholes. Integration of the three methods allows determination of the three-dimensional stress tensor and its spatial variation with depth in a scientific unambiguously way. The stress system is composed of a downhole and a surface unit. The downhole unit consists of hydraulic fracturing equipment (straddle packers and downhole imaging tool) and their associated data acquisition systems. The testing system is state of the art in several aspects including: (1) Large depth range (3 km), (2) Ability to test three borehole dimensions (N=76 mm, H=96 mm, and P=122 mm), (3) Resistivity imager maps the orientation of tested fracture; (4) Highly stiff and resistive to corrosion downhole testing equipment; and (5) Very detailed control on the injection flow rate and cumulative volume is obtained by a hydraulic injection pump with variable piston rate, and a highly sensitive flow-meter. At EGU General Assembly 2017, we would like to

  12. Distributed vibration sensing on optical fibre: field testing in borehole seismic applications (United States)

    Frignet, B.; Hartog, A. H.; Mackie, D.; Kotov, O. I.; Liokumovich, L. B.


    We describe the measurement of seismic waves in a borehole using distributed vibration sensing conveyed on wireline cable. The optical measurement is compared directly with the results of a multi-level borehole seismic survey with conventional electrical accelerometers.

  13. Geology of the Waste Treatment Plant Seismic Boreholes

    Energy Technology Data Exchange (ETDEWEB)

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


    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. Seismic interferometry using multidimensional deconvolution and crosscorrelation for crosswell seismic reflection data without borehole sources

    NARCIS (Netherlands)

    Minato, S.; Matsuoka, T.; Tsuji, T.; Draganov, D.S.; Hunziker, J.W.; Wapenaar, C.P.A.


    Crosswell reflection method is a high-resolution seismic imaging method that uses recordings between boreholes. The need for downhole sources is a restrictive factor in its application, for example, to time-lapse surveys. An alternative is to use surface sources in combination with seismic

  15. Geology of the Waste Treatment Plant Seismic Boreholes

    Energy Technology Data Exchange (ETDEWEB)

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


    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

  16. Numerical Simulation of Hydraulic Fracture Propagation Guided by Single Radial Boreholes

    Directory of Open Access Journals (Sweden)

    Tiankui Guo


    Full Text Available Conventional hydraulic fracturing is not effective in target oil development zones with available wellbores located in the azimuth of the non-maximum horizontal in-situ stress. To some extent, we think that the radial hydraulic jet drilling has the function of guiding hydraulic fracture propagation direction and promoting deep penetration, but this notion currently lacks an effective theoretical support for fracture propagation. In order to verify the technology, a 3D extended finite element numerical model of hydraulic fracturing promoted by the single radial borehole was established, and the influences of nine factors on propagation of hydraulic fracture guided by the single radial borehole were comprehensively analyzed. Moreover, the term ‘Guidance factor (Gf’ was introduced for the first time to effectively quantify the radial borehole guidance. The guidance of nine factors was evaluated through gray correlation analysis. The experimental results were consistent with the numerical simulation results to a certain extent. The study provides theoretical evidence for the artificial control technology of directional propagation of hydraulic fracture promoted by the single radial borehole, and it predicts the guidance effect of a single radial borehole on hydraulic fracture to a certain extent, which is helpful for planning well-completion and fracturing operation parameters in radial borehole-promoted hydraulic fracturing technology.

  17. Modifying Moveout-Based Anisotropic Spreading Correction for Borehole Seismic Data (United States)

    Tamimi, N.


    The higher signal-to-noise ratio of borehole seismic data compared to surface seismic data makes them suitable for amplitude-related analyses and reflection seismic imaging. However, sometimes removing undesirable effects from the amplitude information is necessary. Energy decay due to wavefront spreading (called geometrical spreading) is one of the effects that should be removed before amplitude analysis and imaging in exploration seismic, and it needs special considerations, where the subsurface medium is highly anisotropic. One of the successful surface seismic techniques to compensate for energy decay or amplitude distortion due to geometrical spreading is MASC (Moveout-Based Anisotropic Spreading Correction). However, this technique cannot be used for borehole seismic data easily and needs some modifications. Here, we modified this valuable technique for borehole seismic and applied it to a real field case study. The results show that the modified MASC technique can be applied to borehole seismic data easily with minimum subsurface velocity information.

  18. Study on Initiation Mechanisms of Hydraulic Fracture Guided by Vertical Multi-radial Boreholes (United States)

    Guo, Tiankui; Liu, Binyan; Qu, Zhanqing; Gong, Diguang; Xin, Lei


    The conventional hydraulic fracturing fails in the target oil development zone (remaining oil or gas, closed reservoir, etc.) which is not located in the azimuth of maximum horizontal in situ stress of available wellbores. The technology of directional propagation of hydraulic fracture guided by vertical multi-radial boreholes is innovatively developed. The effects of in situ stress, wellbore internal pressure and fracturing fluid percolation effect on geostress field distribution are taken into account, a mechanical model of two radial boreholes (basic research unit) is established, and the distribution and change rule of the maximum principal stress on the various parameters have been studied. The results show that as the radial borehole azimuth increases, the preferential rock tensile fracturing in the axial plane of radial boreholes becomes increasingly difficult. When the radial borehole azimuth increases to a certain extent, the maximum principal stress no longer appears in the azimuth of the radial boreholes, but will go to other orientations outside the axial plane of radial boreholes and the maximum horizontal stress orientation. Therefore, by reducing the ratio between the distance of the radial boreholes and increasing the diameter of the radial boreholes can enhance the guiding strength. In the axial plane of the radical boreholes, particularly in the radial hole wall, position closer to the radial boreholes is more prone to rock tensile destruction. Even in the case of large radial borehole azimuth, rock still preferentially ruptures in this position. The more the position is perpendicularly far from the axis of the wellbore, the lesser it will be affected by wellbore, and the lesser the tensile stress of each point. Meanwhile, at a certain depth, due to the decrease in the impact of the wellbore and the impact of the two radial boreholes increases accordingly, at the further position from the wellbore axis, the tensile fracture is the most prone to

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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.

  20. Mechanical and hydraulic properties of rocks related to induced seismicity (United States)

    Witherspoon, P.A.; Gale, J.E.


    Witherspoon, P.A. and Gale, J.E., 1977. Mechanical and hydraulic properties of rocks related to induced seismicity. Eng. Geol., 11(1): 23-55. The mechanical and hydraulic properties of fractured rocks are considered with regard to the role they play in induced seismicity. In many cases, the mechanical properties of fractures determine the stability of a rock mass. The problems of sampling and testing these rock discontinuities and interpreting their non-linear behavior are reviewed. Stick slip has been proposed as the failure mechanism in earthquake events. Because of the complex interactions that are inherent in the mechanical behavior of fractured rocks, there seems to be no simple way to combine the deformation characteristics of several sets of fractures when there are significant perturbations of existing conditions. Thus, the more important fractures must be treated as individual components in the rock mass. In considering the hydraulic properties, it has been customary to treat a fracture as a parallel-plate conduit and a number of mathematical models of fracture systems have adopted this approach. Non-steady flow in fractured systems has usually been based on a two-porosity model, which assumes the primary (intergranular) porosity contributes only to storage and the secondary (fracture) porosity contributes only to the overall conductivity. Using such a model, it has been found that the time required to achieve quasi-steady state flow in a fractured reservoir is one or two orders of magnitude greater than it is in a homogeneous system. In essentially all of this work, the assumption has generally been made that the fractures are rigid. However, it is clear from a review of the mechanical and hydraulic properties that not only are fractures easily deformed but they constitute the main flow paths in many rock masses. This means that one must consider the interaction of mechanical and hydraulic effects. A considerable amount of laboratory and field data is now

  1. A Fiber-Optic Borehole Seismic Vector Sensor System for Geothermal Site Characterization and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Paulsson, Bjorn N.P. [Paulsson, Inc., Van Nuys, CA (United States); Thornburg, Jon A. [Paulsson, Inc., Van Nuys, CA (United States); He, Ruiqing [Paulsson, Inc., Van Nuys, CA (United States)


    Seismic techniques are the dominant geophysical techniques for the characterization of subsurface structures and stratigraphy. The seismic techniques also dominate the monitoring and mapping of reservoir injection and production processes. Borehole seismology, of all the seismic techniques, despite its current shortcomings, has been shown to provide the highest resolution characterization and most precise monitoring results because it generates higher signal to noise ratio and higher frequency data than surface seismic techniques. The operational environments for borehole seismic instruments are however much more demanding than for surface seismic instruments making both the instruments and the installation much more expensive. The current state-of-the-art borehole seismic instruments have not been robust enough for long term monitoring compounding the problems with expensive instruments and installations. Furthermore, they have also not been able to record the large bandwidth data available in boreholes or having the sensitivity allowing them to record small high frequency micro seismic events with high vector fidelity. To reliably achieve high resolution characterization and long term monitoring of Enhanced Geothermal Systems (EGS) sites a new generation of borehole seismic instruments must therefore be developed and deployed. To address the critical site characterization and monitoring needs for EGS programs, US Department of Energy (DOE) funded Paulsson, Inc. in 2010 to develop 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 ultra-high temperature and high pressure boreholes. Tests of the fiber optic seismic vector sensors developed on the DOE funding 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

  2. Borehole depth and regolith aquifer hydraulic characteristics of ...

    African Journals Online (AJOL)


    “black-and-white granite” in the borehole logs were identified as biotite gneiss on the field (Figure 3) This rock type is a member of the migmatite-gneiss complex. It is fine- to medium-grained in texture and decomposes to produce an aquifer of fine- to medium-grained clayey sands or sandy clay. Grain size analysis on three.

  3. Visualization of hydraulic connections using Borehole Array around LPG Underground Storage Cavern (United States)

    Shimo, M.; Mashimo, H.; Maejima, T.; Aoki, K.


    This paper presents a systematic approach to visualize the hydraulic connections within the fractured rock mass around the underground LPG storage caverns using array of water injection boreholes. By taking advantage that water injection boreholes are located so as to cover the storage caverns, a complete sketch of hydraulic conditions around the caverns, such as locations of water conducting fractures, hydraulic conductivity and groundwater pressure can be obtained. Applicability of the proposed techniques have been tested in an on-going construction project operated by JOGMEC, Japan Oil, Gas and Metals National Corporation, at Namikata, Western part of Japan. Three 26m x 30m x 485m caverns, located at 150 - 200 m below the ground surface in a granitic rock, are under construction. By systematically monitoring the pressure responses between the neighboring boreholes during drilling of total 387 boreholes around the two propane caverns, a spatial profile of the hydraulic connections and hydraulic conductivity around the caverns has been successfully obtained. Locations of localized depressurized zones created during an arch excavation have been detected by monitoring pressure in each borehole after stopping water supply to that borehole temporarily. Measurement has been conducted using each one of the 302 boreholes, one at a time. Observation shows that there is a clear correlation between total pressure drop and pressure gradient versus time curve on semi-logarithmic plot, dH/log10t, as expected by the numerical prediction. Regions where dH/log10t is larger than a certain criteria, determined by a numerical simulation for flow around a cavern in a rock with uniform hydraulic conductivity, have been evaluated as a depressurized zone caused by insufficient water supply, possibly due to existence of the high permeable zones. Separate pore pressure measurement around the caverns also supports this interpretation that a low pressure is prevailing near the borehole

  4. Characterization of magnetized ore bodies based on three-component borehole magnetic and directional borehole seismic measurements (United States)

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


    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

  5. A Study on the Pressure Relief Scope and the Stress Variation of Hydraulic Flushing Borehole

    Directory of Open Access Journals (Sweden)

    C. F.Wei


    Full Text Available To study the variation of the pressure relief scope and the stress around hydraulic flushing borehole, the theory of coalrock damage was utilized to distinguish the interaction area of water-jet and coal-rock into the coal-rock crushing area, the water-jet pressure stagnation area, the transition area and the original stress recovery area of coal-rock. Based on the actual occurrence conditions of the coal seam, the pressure variation and relief scope around the hydraulic flushing borehole were analyzed and simulated by RFPA2D-Flow software. The results showed that a relief area with the radius of 5.0 ~ 6.0 m around the borehole formed due to the hydraulic flushing with the pressure relief of 0.038 ~ 6.545 MPa, and the maximum principal stress is 15.85 MPa with a distance of 6.8 m from the inspected hole where stress concentration appeared. After hydraulic flushing test, the diameter (441.8 ~ 1171.6 mm of the hole which can be an expression of coal crushing area size, was calculated based on the examination of the coal amount through the trial process, and it can be drawn that the pressure relief area must be larger than that of the coal-rock crushing area. Meanwhile, the measured pressures relief range(5.96 ~ 6.62 m is basically consistent with the numerical simulation result (5.0 ~ 6.0 m which verified the accuracy of the simulation analysis, according to the distance from the inspection drilling to the hydraulic flushing borehole and the decreased degree of the gas content in the inspection hole by the way of Gas Content.

  6. Cross-hole fracture connectivity assessed using hydraulic responses during liner installations in crystalline bedrock boreholes (United States)

    Persaud, Elisha; Levison, Jana; Pehme, Peeter; Novakowski, Kentner; Parker, Beth


    In order to continually improve the current understanding of flow and transport in crystalline bedrock environments, developing and improving fracture system characterization techniques is an important area of study. The presented research examines the installation of flexible, impermeable FLUTe™ liners as a means for assessing cross-hole fracture connectivity. FLUTe™ liners are used to generate a new style of hydraulic pulse, with pressure response monitored in a nearby network of open boreholes drilled in gneissic rock of the Canadian Shield in eastern Ontario, Canada. Borehole liners were installed in six existing 10-15 cm diameter boreholes located 10-35 m apart and drilled to depths ranging between 25-45 m. Liner installation tests were completed consecutively with the number of observation wells available for each test ranging between one and six. The collected pressure response data have been analyzed to identify significant groundwater flow paths between source and observation boreholes as well as to estimate inter-well transmissivity and storativity using a conventional type-curve analysis. While the applied solution relies on a number of general assumptions, it has been found that reasonable comparison can be made to previously completed pulse interference and pumping tests. Results of this research indicate areas where method refinement is necessary, but, nonetheless, highlight the potential for use in crystalline bedrock environments. This method may provide value to future site characterization efforts given that it is complementary to, and can be used in conjunction with, other currently employed borehole liner applications, such as the removal of cross-connection at contaminated sites and the assessment of discrete fracture distributions when boreholes are sealed, recreating natural hydraulic gradient conditions.

  7. Combined use of straddle packer testing and FLUTe profiling for hydraulic testing in fractured rock boreholes (United States)

    Quinn, Patryk; Cherry, John A.; Parker, Beth L.


    A combination of high resolution hydraulic tests using straddle packers and transmissivity (T) profiling using the FLUTe flexible liner method (liner profiling) in densely fractured rock boreholes is shown to be efficient for the determination of the vertical distribution of T along the entire hole. The liner T profiling method takes a few hours or less to scan the entire borehole length resulting in a T profile. Under favorable conditions this method has good reliability for identifying the highest T zones identified by distinct decreases in liner velocity when these zones are covered by the descending liner. In contrast, for one short test interval (e.g., 1-2 m) the multiple-test, straddle-packer method takes a few hours to measure T with good precision and accuracy using a combination of steady-state and transient tests (e.g., constant head step tests, slug tests, and constant rate pumping tests). Because of the time consuming aspect of this multiple-test method, it is most efficient in each borehole to conduct straddle packer testing only in priority zones selected after assessment of other borehole data collected prior to packer testing. The T profile from the liner method is instrumental in selecting high permeable zones for application of the multiple-test method using straddle packers, which in turn, refines the T estimation from the liner profile. Results from three boreholes in densely fractured sandstone demonstrate this approach showing the synergistic use of the methods with emphasis on information important for determining hydraulic apertures.

  8. Nondestructive testing using borehole and surface seismic techniques to evaluate rock mass damage zones

    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P.P.; Stokoe, K.H. II [Univ. of Texas, Austin, TX (United States)


    A suite of seismic tests was performed at the U12g tunnel at the Nevada Test Site. The methods include borehole (crosshole and downhole) and surface (Rayleigh wave and refraction) tests. Results indicate that the different methods should be considered complimentary, and that seismic methods can sensitively evaluate magnitudes and variations of in situ rock mass stiffness. In particular, near-surface low velocity (damage) zones are delineated quite well with Rayleigh wave and downhole methods.

  9. Integrated In Situ Stress Estimation by Hydraulic Fracturing, Borehole Observations and Numerical Analysis at the EXP-1 Borehole in Pohang, Korea (United States)

    Kim, Hanna; Xie, Linmao; Min, Ki-Bok; Bae, Seongho; Stephansson, Ove


    It is desirable to combine the stress measurement data produced by different methods to obtain a more reliable estimation of in situ stress. We present a regional case study of integrated in situ stress estimation by hydraulic fracturing, observations of borehole breakouts and drilling-induced fractures, and numerical modeling of a 1 km-deep borehole (EXP-1) in Pohang, South Korea. Prior to measuring the stress, World Stress Map (WSM) and modern field data in the Korean Peninsula are used to construct a best estimate stress model in this area. Then, new stress data from hydraulic fracturing and borehole observations is added to determine magnitude and orientation of horizontal stresses. Minimum horizontal principal stress is estimated from the shut-in pressure of the hydraulic fracturing measurement at a depth of about 700 m. The horizontal stress ratios ( S Hmax/ S hmin) derived from hydraulic fracturing, borehole breakout, and drilling-induced fractures are 1.4, 1.2, and 1.1-1.4, respectively, and the average orientations of the maximum horizontal stresses derived by field methods are N138°E, N122°E, and N136°E, respectively. The results of hydraulic fracturing and borehole observations are integrated with a result of numerical modeling to produce a final rock stress model. The results of the integration give in situ stress ratios of 1.3/1.0/0.8 ( S Hmax/ S V/ S hmin) with an average azimuth of S Hmax in the orientation range of N130°E-N136°E. It is found that the orientation of S Hmax is deviated by more than 40° clockwise compared to directions reported for the WSM in southeastern Korean peninsula.

  10. A comprehensive approach for evaluating network performance in surface and borehole seismic monitoring (United States)

    Stabile, T. A.; Iannaccone, G.; Zollo, A.; Lomax, A.; Ferulano, M. F.; Vetri, M. L. V.; Barzaghi, L. P.


    The accurate determination of locations and magnitudes of seismic events in a monitored region is important for many scientific, industrial and military studies and applications; for these purposes a wide variety of seismic networks are deployed throughout the world. It is crucial to know the performance of these networks not only in detecting and locating seismic events of different sizes throughout a specified source region, but also by evaluating their location errors as a function of the magnitude and source location. In this framework, we have developed a method for evaluating network performance in surface and borehole seismic monitoring. For a specified network geometry, station characteristics and a target monitoring volume, the method determines the lowest magnitude of events that the seismic network is able to detect (Mwdetect), and locate (Mwloc) and estimates the expected location and origin time errors for a specified magnitude. Many of the features related to the seismic signal recorded at a single station are considered in this methodology, including characteristics of the seismic source, the instrument response, the ambient noise level, wave propagation in a layered, anelastic medium and uncertainties on waveform measures and the velocity model. We applied this method to two different network typologies: a local earthquake monitoring network, Irpinia Seismic Network (ISNet), installed along the Campania-Lucania Apennine chain in Southern Italy, and a hypothetic borehole network for monitoring microfractures induced during the hydrocarbon extraction process in an oil field. The method we present may be used to aid in enhancing existing networks and/or understanding their capabilities, such as for the ISNet case study, or to optimally design the network geometry in specific target regions, as for the borehole network example.

  11. Aespoe Hard Rock Laboratory. Backfill and Plug test. Hydraulic testing of core drilled boreholes in the ZEDEX drift

    Energy Technology Data Exchange (ETDEWEB)

    Ludvigson, Jan-Erik; Nordqvist, Rune; Ekman, Lennart; Hansson, Kent (GEOSIGMA AB, Uppsala (Sweden))


    The present report documents the performance and results of hydraulic testing in selected core boreholes in the Zedex drift. The holes will be used as rock instrumentation boreholes during the Backfill and Plug Test at Aespoe HRL. The testing involves both 1 m long boreholes with 56 mm diameter as well as longer boreholes c. 5 m, 8 m and 25 m long with 56 mm or 76 mm diameter. Only single-hole tests were performed. The tests were carried out as short-time constant head injection tests since all boreholes tested (except one) were non-flowing before tests. The injection phase was followed by a pressure recovery phase. Furthermore, the tests were carried out as single-packer tests. A specially designed test system was used for the tests. The main evaluation of the tests was performed on data from the recovery phase by a new approach based on a non-linear regression technique combined with a flow simulation model (SUTRA). The tests in the 1 m-holes (testing the interval c. 0.3-0.7 m in the rock perpendicular to the tunnel face) show that the hydraulic conductivity of the superficial rock around the Zedex drift in general is low. However, during testing in some boreholes, visible leakage in the rock occurred through superficial fractures into the tunnel. These fractures were mainly located in the floor of the Zedex drift and are probably blast-induced. These fractures have a high hydraulic conductivity. The tests in the longer boreholes show that the hydraulic conductivity further into the rock in general is below c. 1x10-10 m/s. Increased hydraulic conductivity (c.1.5x10-8 m/s) was only observed in the flowing borehole KXZSD8HL.

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

    Energy Technology Data Exchange (ETDEWEB)

    Paulsson Geophysical Services


    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.

  13. Experimental Study of Crack Initiation and Extension Induced by Hydraulic Fracturing in a Tree-Type Borehole Array

    Directory of Open Access Journals (Sweden)

    Yiyu Lu


    Full Text Available High-pressure hydraulic fracturing technology in coal and coal bed methane mines can lead to roof and floor damage, and fracture initiation disorder that leads to a “blank area”, and other issues. A new method of hydraulic fracturing is proposed to increase the homogeneous permeability of coal in underground coalmines. Numerical and other simulation tests for different forms of a tree-type, branched borehole model are presented. The results show that the branched array causes cracks to initiate from the bottom of the array, and these extend along the direction of the adjacent boreholes. Generally, as the number of branched boreholes increases, the coal seam fracture network also increase, improving the distribution of the fracture network, making the fracturing effect better. The branched boreholes appear to reduce initiation pressure and, with increasing branches, the initiation pressure decreases. A model with four tree-type, branched boreholes leads to a reduction in initiation pressure of 69%. In terms of permeability improvement technology in underground coalmines, a branched hydraulic fracturing borehole array has the advantages of reducing initiation pressure, controlling crack initiation and extension, enhancing the fracturing effect and reducing the destruction of the roof and floor.

  14. Borehole seismic data processing and interpretation: New free software (United States)

    Farfour, Mohammed; Yoon, Wang Jung


    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.

  15. The derivation of an anisotropic velocity model from a combined surface and borehole seismic survey in crystalline environment at the COSC-1 borehole, central Sweden (United States)

    Simon, H.; Buske, S.; Krauß, F.; Giese, R.; Hedin, P.; Juhlin, C.


    The Scandinavian Caledonides provide a well-preserved example of a Palaeozoic continent-continent collision, where surface geology in combination with geophysical data provides information about the geometry of parts of the Caledonian structure. The project COSC (Collisional Orogeny in the Scandinavian Caledonides) investigates the structure and physical conditions of the orogen units and the underlying basement with two approximately 2.5 km deep cored boreholes in western Jämtland, central Sweden. In 2014, the COSC-1 borehole was successfully drilled through a thick section of the Seve Nappe Complex. This tectonostratigraphic unit, mainly consisting of gneisses, belongs to the so-called Middle Allochthons and has been ductilely deformed and transported during the collisional orogeny. After the drilling, a major seismic survey was conducted in and around the COSC-1 borehole with the aim to recover findings on the structure around the borehole from core analysis and downhole logging. The survey comprised both seismic reflection and transmission experiments, and included zero-offset and multiazimuthal walkaway Vertical Seismic Profile (VSP) measurements, three long offset surface lines centred on the borehole, and a limited 3-D seismic survey. In this study, the data from the multiazimuthal walkaway VSP and the surface lines were used to derive detailed velocity models around the COSC-1 borehole by inverting the first-arrival traveltimes. The comparison of velocities from these tomography results with a velocity function calculated directly from the zero-offset VSP revealed clear differences in velocities for horizontally and vertically travelling waves. Therefore, an anisotropic VTI (transversely isotropic with vertical axis of symmetry) model was found that explains first-arrival traveltimes from both the surface and borehole seismic data. The model is described by a vertical P-wave velocity function derived from zero-offset VSP and the Thomsen parameters ε = 0

  16. Stochastic estimation of aquifer geometry using seismic refraction data with borehole depth constraints

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; Hubbard, S.S.; Gaines, D.; Korneev, V.; Baker, G.; Watson, D.


    We develop a Bayesian model to invert surface seismic refraction data with depth constraints from boreholes for characterization of aquifer geometry and apply it to seismic and borehole datasets collected at the contaminated Oak Ridge National Laboratory site in Tennessee. Rather than the traditional approach of first inverting the seismic arrival times for seismic velocity and then using that information to aid in the spatial interpolation of wellbore data, we jointly invert seismic first arrival time data and wellbore-based information, such as depths of key lithological boundaries. We use a staggered-grid finite-difference algorithm with second order accuracy in time and fourth order accuracy in space to model seismic full waveforms and use an automated method to pick the first arrival times. We use Markov Chain Monte Carlo methods to draw many samples from the joint posterior probability distribution, on which we can estimate the key interfaces and their associated uncertainty as a function of horizontal location and depth. We test the developed method on both synthetic and field case studies. The synthetic studies show that the developed method is effective at rigorous incorporation of multiscale data and the Bayesian inversion reduces uncertainty in estimates of aquifer zonation. Applications of the approach to field data, including two surface seismic profiles located 620 m apart from each other, reveal the presence of a low-velocity subsurface zone that is laterally persistent. This geophysically-defined feature is aligned with the plume axis, suggesting it may serve as an important regional preferential flow pathway.

  17. Hydraulically conductive fractures and their properties in boreholes KR4 and KR7 - KR10 at Olkiluoto site

    Energy Technology Data Exchange (ETDEWEB)

    Hellae, P.; Tammisto, E.; Ahokas, H. [JP-Fintact Oy (Finland)


    As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the prevailing hydrological conditions at the Olkiluoto island. Hydraulic properties of fractures are of interest for the groundwater flow modelling and for planning of grouting and analysis of leakages etc. The detailed flow logging with 0.5 m test interval and made in 10 cm steps is used for exact depth determination of hydraulically conductive fractures or fracture zones. Together with borehole wall images flow logging provides possibilities to detect single conductive fractures. The results of flow logging are combined to the fracture data and other rock properties. Boreholes KR4, KR7, KR8, KR9 and KR10 have been selected as pilot holes. The conductive fractures were recognised from the images primarily based on a visible flow traces along the image. In most of the cases of measured flow, no visible flow traces were seen in the image. In these cases the most probable fracture(s) to conduct the flow were picked using the single point resistance measurements as supportive information. In order to be able to analyse the properties of the hydraulically conductive fractures, the fractures in the mineralogical/drilling report corresponding to the ones picked from the borehole wall image were identified. The combination was done based on matching the depth, intersection angle and other fracture properties (reported large aperture or thickness etc.). The results from boreholes KR7 and KR8 were checked also from the core sample. According to the results the hydraulically conductive fractures/zones could be distinguished from the borehole wall images in most cases. An important phase in the work is to calibrate the depth of the image and the flow logging with the sample length. Checking results from the core samples is essential in order to reliably correlate the borehole wall fractures to the core sample mappings. The hydraulic conductivity is clearly higher in the upper part

  18. Estimation of Field-scale Aquifer Hydraulic and Sorption Parameters Based on Borehole Spectral Gamma Methods (United States)

    Ward, A. L.; Draper, K.; Hasan, N.


    Knowledge of spatially variable aquifer hydraulic and sorption parameters is a pre-requisite for an improved understanding of the transport and spreading of sorbing solutes and for the development of effective strategies for remediation. Local-scale estimates of these parameters are often derived from core measurements but are typically not representative of field values. Fields-scale estimates are typically derived from pump and tracer tests but often lack the spatial resolution necessary to deconvolve the effects of fine-scale heterogeneities. Geophysical methods have the potential to bridge this gap both in terms of coverage and resolution, provided meaningful petrophysical relationships can be developed. The objective of this study was to develop a petrophysical relationship between soil textural attributes and the gamma-energy response of natural sediments. Measurements from Hanford’s 300 Area show the best model to be a linear relationship between 232Th concentration and clay content (R2 = 94%). This relationship was used to generate a 3-D distribution of clay mass fraction based on borehole spectral gamma logs. The distribution of clay was then used to predict distributions of permeability, porosity, bubbling pressure, and the pore-size distribution index, all of which are required for predicting variably saturated flow, as well as the specific surface area and cation exchange capacity needed for reactive transport predictions. With this approach, it is possible to obtain reliable estimates of hydraulic properties in zones that could not be characterized by field or laboratory measurements. The spatial distribution of flow properties is consistent with lithologic transitions inferred from geologist’s logs. A preferential flow path, identified from solute and heat tracer experiments and attributed to an erosional incision in the low-permeability Ringold Formation, is also evident. The resulting distributions can be used as a starting model for the

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

    Energy Technology Data Exchange (ETDEWEB)

    Bjorn N. P. Paulsson


    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

  20. Hydraulically conductive fractures and their properties in boreholes KR4 and KR7 - KR10 at Olkiluoto site, Eurajoki

    Energy Technology Data Exchange (ETDEWEB)

    Hellae, P.; Tammisto, E.; Ahokas, H. [Jaakko Poeyry Infra Fintact Oy, Vantaa (Finland)


    As part of the program for the final disposal of the nuclear fuel waste, Posiva Oy investigates the prevailing hydrological conditions at the Olkiluoto Island. Hydraulic properties of fractures are of interest for the groundwater flow modelling, planning of grouting, analysis of leakages etc. This paper presents the results of a pilot study carried out to combine the results of detailed flow logging with borehole wall images and core mapping and thereby to describe properties of single conductive fractures. (orig.)

  1. Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography

    Energy Technology Data Exchange (ETDEWEB)

    Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.


    In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

  2. Assessing the induced seismicity by hydraulic fracturing at the Wysin site (Poland) (United States)

    Ángel López Comino, José; Cesca, Simone; Kriegerowski, Marius; Heimann, Sebastian; Dahm, Torsten; Mirek, Janusz; Lasocky, Stanislaw


    Induced seismicity related to industrial processes including shale gas and oil exploitation is a current issues that implies enough reasons to be concerned. Hydraulic fracturing usually induces weak events. However, scenarios with larger earthquakes are possible, e.g. if the injected fluids alter friction conditions and trigger the failure of neighbouring faults. This work is focused on a hydrofracking experiment monitored in the framework of the SHEER (SHale gas Exploration and Exploitation induced Risks) EU project at the Wysin site, located in the central-western part of the Peribaltic synclise of Pomerania, Poland. A specific network setup has been installed combining surface installation with three small-scale arrays and a shallow borehole installation. The fracking operations were carried out in June and July 2016 at a depth 4000 m. The monitoring has been operational before, during and after the termination of hydraulic fracturing operations. We apply a recently developed automated full waveform detection algorithm based on the stacking of smooth characteristic function and the identification of high coherence in the signals recorded at different stations. The method was tested with synthetic data and different detector levels yielding values of magnitude of completeness around 0.1. An unsupervised detection catalogue is generated with real data for a time period May-September 2016. We identify strong temporal changes (day/night) of the detection performance. A manual revision of the detected signals reveals that most detections are associated to local and regional seismic signals. Only two events could be assigned to the volume potentially affected by the fracking operations.

  3. Evolution of Neural Networks for the Prediction of Hydraulic Conductivity as a Function of Borehole Geophysical Logs: Shobasama Site, Japan (United States)

    Reeves, P.; McKenna, S. A.; Takeuchi, S.; Saegusa, H.


    In situ measurements of hydraulic conductivity in fractured rocks are expensive to acquire. Borehole geophysical measurements are relatively inexpensive to acquire but do not provide direct information on hydraulic conductivity. These geophysical measurements quantify properties of the rock that influence the hydraulic conductivity and it may be possible to employ a non-linear combination of these measurements to estimate hydraulic conductivity. Geophysical measurements collected in fractured granite at the Shobasama site in central Japan were used as the input to a feed-forward neural network. A simple genetic algorithm was used to simultaneously evolve the architecture and parameters of the neural network as well as determine an optimal subset of geophysical measurements for the prediction of hydraulic conductivity. The initial estimation procedure focused on predicting the class of the hydraulic conductivity, high, medium or low, from the geophysical measurements. This estimation was done while using the genetic algorithm to simultaneously determine the most important geophysical logs and optimize the architecture of the neural network. Results show that certain geophysical logs provide more information than others- most notably the short-normal resistivity, micro-resistivity, porosity and sonic logs provided the most information on hydraulic conductivity. The neural network produced excellent training results with accuracy of 90 percent or greater, but was unable to produce accurate predictions of the hydraulic conductivity class In the second phase of calculations, the selection of geophysical measurements is limited to only those that provide significant information. Additionally, this second phase predicts transmissivity instead of hydraulic conductivity in order to account for the differences in the length of the hydraulic test zones. Resulting predictions of transmissivity exhibit conditional bias with maximum prediction errors of three orders of magnitude

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

    DEFF Research Database (Denmark)

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

    of 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 lengths from 7 to 25 km. The infill comprises till, glaciofluvial sand, and glaciolacustrine clay and silt. Younger tunnel valleys are found to often re-use pre-established valleys generating cut-and-fill structures which are clearly revealed on the reflection seismic profiles. Cross-cutting relations...

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

    DEFF Research Database (Denmark)

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

    of 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 lengths from 7 to 25 km. The infill comprises till, glaciofluvial sand, and glaciolacustrine clay and silt. Younger tunnel valleys are found to often re-use pre-established valleys generating cut-and-fill structures which are clearly revealed on the reflection seismic profiles. Cross-cutting relations...

  6. Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs (United States)

    We have conducted numerical simulation studies to assess the potential for injection-induced fault reactivation and notable seismic events associated with shale-gas hydraulic fracturing operations. The modeling is generally tuned toward conditions usually encountered in the Marce...

  7. 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

    Energy Technology Data Exchange (ETDEWEB)

    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)


    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.

  8. A hydraulic test device for free-flowing artesian boreholes with a ...

    African Journals Online (AJOL)

    Accurate parameter estimation for aquifers is very challenging, particularly for artesian aquifers in which the potentiometric surface is above ground level. A common approach to parameter estimation for artesian aquifers is to make use of free-flowing and recovery tests. However, such aquifer tests on artesian boreholes are ...

  9. A hydraulic test device for free-flowing artesian boreholes with a ...

    African Journals Online (AJOL)


    Oct 22, 2013 ... associated with deep-seated tectonic movements in the Earth's crust, provide a route for large, deep-circulating volumes of groundwater under artesian pressure. In terms of the height of the pressure head, flowing artesian boreholes drilled into arte- sian TMG aquifers can be classified into 3 categories:.

  10. Hydraulic Properties of a Strike-slip Fault Estimated from Periodic Pumping Tests in Borehole GDP-1 at Grimselpass, Switzerland (United States)

    Cheng, Y.; Renner, J.


    Periodic pumping tests were conducted using a double-packer probe placed at four different depth levels in borehole GDP-1 at Grimselpass, Central Swiss Alps, penetrating a hydrothermally active fault. The tests had the objective to assess the use of periodic testing in the context for design and quality control of hydraulically stimulated geothermal reservoirs. We employed periods between 60 and 1080 s and nominal flow rates between 0 and 10 l/min. Amplitude ratio and phase shift between the pressure and flow rate in the pumping interval corrected for the storage capacity of the tubing are compared to analytical predictions of conventional 1D and radial flow models but also to those for bilinear flow and radial flow in a system composed of cylindrical shells with distinct hydraulic properties concentrically arranged around the well (injectivity analysis). The order of magnitude of derived transmissivity values agrees with that gained from conventional hydraulic tests. The field campaign revealed several advantages of the periodic testing, e.g., short testing time since a periodic signal can easily be separated from changing background pressure by detrending and Fourier transformation. The mismatch between test results and the considered analytical models indicates a hydraulically complex and heterogeneous subsurface. Attenuation and phase shift between the periodic pressure signals above or below packers and in the interval (interference analysis) are addressed by an exploratory numerical modelling of the non-radial flow situation. Interference analysis of a single well provides data that are not affected by uncertainties in the timing of flow-rate changes. The exploratory modeling shows consistent results and improves diffusivity estimation. Yet, more comprehensive modeling will be required to take full advantage of all the pressure records typically acquired when using a double-packer probe.

  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

    Directory of Open Access Journals (Sweden)

    Cowper, David


    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. Co-seismic strain changes of Wenchuan Mw7. 9 earthquake recorded by borehole strainmeters on Tibetan plateau

    Directory of Open Access Journals (Sweden)

    Fu Guangyu


    Full Text Available Co-seismic strain changes of the Wenchuan Mw7. 9 earthquake recorded with three four-component borehole strainmeters showed NW-SE and roughly EW extensions, respectively, at two locations in the interior and northern part of Tibetan plateau, and NS shortening at a location south of the epicenter, in agreement with the tectonic stress field of this region. The observed values of as much as 10−7 are, however, larger than theoretical values obtained with half-space and spherical-earth dislocation theories, implying the existence of other effects, such as local crustal structure and initial stress.

  13. Induced seismicity caused by hydraulic fracturing in deep geothermal wells in Germany and adjacent areas (United States)

    Plenefisch, Thomas; Brückner, Lisa; Ceranna, Lars; Gestermann, Nicolai; Houben, Georg; Tischner, Torsten; Wegler, Ulrich; Wellbrink, Matthias; Bönnemann, Christian; Bertram, Andreas; Kirschbaum, Bernd


    Recently, the BGR has worked out a study on the potential environmental impact caused by hydraulic fracturing or chemical stimulations in deep geothermal reservoirs in Germany and adjacent areas. The investigations and analyses are based on existing studies and information provided by operators. The two environmental impacts being essentially considered in the report are induced seismicity and possible contamination of the groundwater reservoirs which serve for drinking water supply. Altogether, in this study, information on 30 hydraulic frac operations and 26 chemical stimulations including information from neighboring countries were compiled and analyzed. Out of the hydraulic stimulations two thirds were carried out as waterfracs and one third as fracturing with proppants. Parameters used in the study to characterize the induced seismicity are maximum magnitude, number of seismic events, size of the seismically active volume, and the relation of this volume to fault zones and the cap rock, as well as, finally, the impacts at the Earth's surface. The response of the subsurface to hydraulic fracturing is variable: There are some activities, which cause perceptible seismic events, others, where no perceptible but instrumentally detected events occurred, and moreover activities without even any instrumentally detected events. A classification of seismic hazard with respect to tectonic region, geology, or depth of the layer is still difficult, since the number of hydraulic fracturing measures in deep geothermal wells is small making a statistically sound analysis impossible. However, there are some indications, that hydraulic fracturing in granite in tectonically active regions like the Upper Rhine Graben results in comparatively stronger, perceptible seismicity compared to hydraulic fracturing in the sedimentary rocks of the North German basin. The maximum magnitudes of induced earthquakes caused by hydraulic fracturing of deep geothermal wells in Germany are

  14. Flowing fluid electrical conductivity logging of a deep borehole during and following drilling: estimation of transmissivity, water salinity and hydraulic head of conductive zones (United States)

    Doughty, Christine; Tsang, Chin-Fu; Rosberg, Jan-Erik; Juhlin, Christopher; Dobson, Patrick F.; Birkholzer, Jens T.


    Flowing fluid electrical conductivity (FFEC) logging is a hydrogeologic testing method that is usually conducted in an existing borehole. However, for the 2,500-m deep COSC-1 borehole, drilled at Åre, central Sweden, it was done within the drilling period during a scheduled 1-day break, thus having a negligible impact on the drilling schedule, yet providing important information on depths of hydraulically conductive zones and their transmissivities and salinities. This paper presents a reanalysis of this set of data together with a new FFEC logging data set obtained soon after drilling was completed, also over a period of 1 day, but with a different pumping rate and water-level drawdown. Their joint analysis not only results in better estimates of transmissivity and salinity in the conducting fractures intercepted by the borehole, but also yields the hydraulic head values of these fractures, an important piece of information for the understanding of hydraulic structure of the subsurface. Two additional FFEC logging tests were done about 1 year later, and are used to confirm and refine this analysis. Results show that from 250 to 2,000 m depths, there are seven distinct hydraulically conductive zones with different hydraulic heads and low transmissivity values. For the final test, conducted with a much smaller water-level drawdown, inflow ceased from some of the conductive zones, confirming that their hydraulic heads are below the hydraulic head measured in the wellbore under non-pumped conditions. The challenges accompanying 1-day FFEC logging are summarized, along with lessons learned in addressing them.

  15. Seismicity Induced by Hydraulic Fracturing in Shales: A Bedding Plane Slip Model (United States)

    Staněk, František; Eisner, Leo


    Passive seismic monitoring of microseismic events induced in oil or gas reservoirs is known as microseismic monitoring. Microseismic monitoring is used to understand the process of hydraulic fracturing, which is a reservoir stimulation technique. We use a new geomechanical model with bedding plane slippage induced by hydraulic fractures within shale reservoirs to explain seismicity observed in a typical case study of hydraulic fracturing of a shale gas play in North America. Microseismic events propagating from the injection point are located at similar depths (within the uncertainty of their locations), and their source mechanisms are dominated by shear failure with both dip-slip and strike-slip senses of motion. The prevailing dip-slip mechanisms have one nearly vertical nodal plane perpendicular to the minimum horizontal stress axis, while the other nodal plane is nearly horizontal. Such dip-slip mechanisms can be explained by slippage along bedding planes activated by the aseismic opening of vertical hydraulic fractures. The model explains the observed prevailing orientation of the shear planes of the microseismic events, as well as the large difference between seismic and hydraulic energy.

  16. Fatigue hydraulic fracturing by cyclic reservoir treatment enhances permeability and reduces induced seismicity (United States)

    Zang, Arno; Yoon, Jeoung Seok; Stephansson, Ove; Heidbach, Oliver


    The occurrence of induced seismic events during hydraulic fracturing of reservoirs to enhance permeability is an unavoidable process. Due to the increased public concern with respect to the risks imposed by induced seismicity, however, the development of a soft stimulation method is needed creating higher permeability with less induced seismicity. We use a discrete element model of naturally fractured rock with pore fluid flow algorithm in order to analyse two scenarios of high-pressure fluid injection (hydraulic fracturing) at depth and associated induced seismicity. The ratio of pumped-in energy to released seismic energy is in agreement with field data. Our results suggest that cyclic reservoir treatment is a safer alternative to conventional hydraulic fracture stimulation as both, the total number of induced events as well as the occurrence of larger magnitude events are lowered. This work is motivated by results of laboratory triaxial indenter tests on granite rock samples where continuous loading leads to a wide fracture process zone while cyclic treatment with frequent starting and stopping of loading fatigues the rock, resulting in smaller damage volume and more persistent fracture growth.

  17. Effect of Injection Site on Fault Activation and Seismicity during Hydraulic Fracturing

    Directory of Open Access Journals (Sweden)

    Zhaohui Chong


    Full Text Available Hydraulic fracturing is a key technology to stimulate oil and gas wells to increase production in shale reservoirs with low permeability. Generally, the stimulated reservoir volume is performed based on pre-existing natural fractures (NF. Hydraulic fracturing in shale reservoirs with large natural fractures (i.e., faults often results in fault activation and seismicity. In this paper, a coupled hydro-mechanical model was employed to investigate the effects of injection site on fault activation and seismicity. A moment tensor method was used to evaluate the magnitude and affected areas of seismic events. The micro-parameters of the proposed model were calibrated through analytical solutions of the interaction between hydraulic fractures (HF and the fault. The results indicated that the slip displacement and activation range of the fault first decreased, then remained stable with the increase in the distance between the injection hole and the fault (Lif. In the scenario of the shortest Lif (Lif = 10 m, the b-value—which represents the proportion of frequency of small events in comparison with large events—reached its maximum value, and the magnitude of concentrated seismic events were in the range of −3.5 to −1.5. The frequency of seismic events containing only one crack was the lowest, and that of seismic events containing more than ten cracks was the highest. The interaction between the injection-induced stress disturbance and fault slip was gentle when Lif was longer than the critical distance (Lif = 40–50 m. The results may help optimize the fracturing treatment designs during hydraulic fracturing.

  18. A pseudospectral method for the simulation of 3-D ultrasonic and seismic waves in heterogeneous poroelastic borehole environments (United States)

    Sidler, Rolf; Carcione, José M.; Holliger, Klaus


    We present a novel approach for the comprehensive, flexible and accurate simulation of poroelastic wave propagation in 3-D cylindrical coordinates. An important application of this method is the realistic modelling of complex seismic wave phenomena in fluid-filled boreholes, which represents a major, as of yet largely unresolved, problem in exploration geophysics. To this end, we consider a numerical mesh consisting of three concentric domains representing the borehole fluid in the centre followed by the mudcake and/or casing, and the surrounding porous formation. The spatial discretization is based on a Chebyshev expansion in the radial direction and Fourier expansions in the vertical and azimuthal directions as well as a Runge-Kutta integration scheme for the time evolution. Trigonometric interpolation and a domain decomposition method based on the method of characteristics are used to match the boundary conditions at the fluid/porous-solid and porous-solid/porous-solid interfaces as well as to reduce the number of gridpoints in the innermost domain for computational efficiency. We apply this novel modelling approach to the particularly challenging scenario of near-surface borehole environments. To this end, we compare 3-D heterogeneous and corresponding rotationally invariant simulations, assess the sensitivity of Stoneley waves to formation permeability in the presence of a casing and evaluate the effects of an excavation damage zone behind a casing on sonic log recordings. Our results indicate that only first arrival times of fast modes are reasonably well described by rotationally invariant approximations of 3-D heterogenous media. We also find that Stoneley waves are indeed remarkably sensitive to the average permeability behind a perforated PVC casing, and that the presence of an excavation damage zone behind a casing tends to dominate the overall signature of recorded seismograms.

  19. Comparison of borehole geophysics, CPT, resistivity, GPR, and high-resolution seismic data across a shallow structure in unconsolidated sediments

    Energy Technology Data Exchange (ETDEWEB)

    Temples, T.J.; Wyatt, D.E.; Cumbest, R.; Waddell, M.G.


    The geological characterization of the shallow subsurface in the unconsolidated sediments of the Atlantic Coastal Plain, and other unconsolidated sediment regimes, may involve faulting and channeling not readily detectable by conventional drilling and mapping. A knowledge of these features is required in environment and geotechnical studies in areas that may have critical impact to groundwater flow and contaminant transport. In many cases, shallow structural influences are missed during site characterization. A case study is presented using ground penetrating radar (GPR) and high resolution seismic data, compared with a geologic interpretation from borehole logs and core data, with Wenner and dipole-dipole resistivity data and with cone penetrometer (CPT) data in an area where shallow structure is probable and contamination exists.

  20. Scaling of postinjection-induced seismicity: An approach to assess hydraulic fracturing related processes (United States)

    Johann, Lisa; Dinske, Carsten; Shapiro, Serge


    Fluid injections into unconventional reservoirs have become a standard for the enhancement of fluid-mobility parameters. Microseismic activity during and after the injection can be frequently directly associated with subsurface fluid injections. Previous studies demonstrate that postinjection-induced seismicity has two important characteristics: On the one hand, the triggering front, which corresponds to early and distant events and envelops farthest induced events. On the other hand, the back front, which describes the lower boundary of the seismic cloud and envelops the aseismic domain evolving around the source after the injection stop. A lot of research has been conducted in recent years to understand seismicity-related processes. For this work, we follow the assumption that the diffusion of pore-fluid pressure is the dominant triggering mechanism. Based on Terzaghi's concept of an effective normal stress, the injection of fluids leads to increasing pressures which in turn reduce the effective normal stress and lead to sliding along pre-existing critically stressed and favourably oriented fractures and cracks. However, in many situations, spatio-temporal signatures of induced events are captured by a rather non-linear process of pore-fluid pressure diffusion, where the hydraulic diffusivity becomes pressure-dependent. This is for example the case during hydraulic fracturing where hydraulic transport properties are significantly enhanced. For a better understanding of processes related to postinjection-induced seismicity, we analytically describe the temporal behaviour of triggering and back fronts. We introduce a scaling law which shows that postinjection-induced events are sensitive to the degree of non-linearity and to the Euclidean dimension of the seismic cloud (see Johann et al., 2016, JGR). To validate the theory, we implement comprehensive modelling of non-linear pore-fluid pressure diffusion in 3D. We solve numerically for the non-linear equation of

  1. Hydraulic Conductivity Measurements with HTU at Eurajoki, Olkiluoto, Borehole OL-KR15 and OL-KR15B, Year 2004

    Energy Technology Data Exchange (ETDEWEB)

    Haemaelaeinen, H.


    As a part of the site investigations for the disposal of spent nuclear fuel, hydraulic conductivity measurements were carried out in borehole OL-KR15 at Eurajoki, Olkiluoto. The objective was to investigate the distribution of the hydraulic conductivity in the surrounding bedrock volume. Measurements were carried out during 2003-2004 in two phases. The total length of the borehole OL-KR15 is 518,85 m and 158 45,14 m. Of the 471 ,5 m + 44,5 m total measurable length 414 m was covered with 237 standard tests with 2 m packer separation as specified in the research plan, partly with 1 m overlaps. 259 tests were initiated, but some of them ended to hardware or software errors or unsuitable parameter values. Double-packer constant-head method was used throughout with nominal 200 kPa overpressure. Injection stage lasted normally 20 minutes and fall-off stage 10 minutes. The tests were often shortened if there were clear indications that the hydraulic conductivity is below the measuring range of the system. The pressure in the test section was let to stabilise at least 5 min before injection. In some test sections the stabilisation or injection stage lasted several hours. Two transient (Horner and 1/Q) interpretations and one stationary-state (Moye) interpretation were made in-situ immediately after the test. The Hydraulic Testing Unit (HTU-system) is owned by Posiva Oy and it was operated by Geopros Oy. (orig.)

  2. Identification of Hydraulic Fracture Orientation from Ground Surface Using the Seismic Moment Tensor

    Directory of Open Access Journals (Sweden)

    E.V. Birialtcev


    Full Text Available Microseismic monitoring from ground surface is applied in the development of hard-to-recover reserves, especially in the process of hydraulic fracturing (HF. This paper compares several methods of HF microseismic monitoring from the surface, including diffraction stacking, time reverse modeling, and spectral methods. In (Aki and Richards, 1980 it is shown that signal enhancement from seismic events under correlated noises significantly improves when applying the maximum likelihood method. The maximum likelihood method allows to exclude influence of the correlated noise, and also to estimate the seismic moment tensor from ground surface. Estimation of the seismic moment tensor allows to detect type and orientation of source. Usually, the following source types are identified: “Explosion Point” (EXP, “Tensile Crack” (TC, “Double-Couple” (DC and “Compensated Linear Vector Dipole” (CLVD. The orientation of the hydraulic fracture can be estimated even when there is no obvious asymmetry of the spatial distribution of the cloud of events. The features of full-wave location technology are presented. The paper also reviews an example of microseismic monitoring of hydraulic fracturing when there is no obvious asymmetry of microseismic activity cloud, but due to the estimation of the seismic moment tensor it becomes possible to identify with confidence the dominant direction of the fracture.

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

    Energy Technology Data Exchange (ETDEWEB)

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


    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

  4. Seismic Proofing Capability of the Accumulated Semiactive Hydraulic Damper as an Active Interaction Control Device with Predictive Control

    National Research Council Canada - National Science Library

    Shih, Ming-Hsiang; Sung, Wen-Pei


    .... To improve the seismic proofing capability of Accumulated Semiactive Hydraulic Damper, it is converted to an Active Interaction Control device and synchronous control and predictive control methods are proposed...

  5. Modeling of fault reactivation and induced seismicity during hydraulic fracturing of shale-gas reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Rutqvist, Jonny; Rinaldi, Antonio P.; Cappa, Frédéric; Moridis, George J.


    We have conducted numerical simulation studies to assess the potential for injection-induced fault reactivation and notable seismic events associated with shale-gas hydraulic fracturing operations. The modeling is generally tuned towards conditions usually encountered in the Marcellus shale play in the Northeastern US at an approximate depth of 1500 m (~;;4,500 feet). Our modeling simulations indicate that when faults are present, micro-seismic events are possible, the magnitude of which is somewhat larger than the one associated with micro-seismic events originating from regular hydraulic fracturing because of the larger surface area that is available for rupture. The results of our simulations indicated fault rupture lengths of about 10 to 20 m, which, in rare cases can extend to over 100 m, depending on the fault permeability, the in situ stress field, and the fault strength properties. In addition to a single event rupture length of 10 to 20 m, repeated events and aseismic slip amounted to a total rupture length of 50 m, along with a shear offset displacement of less than 0.01 m. This indicates that the possibility of hydraulically induced fractures at great depth (thousands of meters) causing activation of faults and creation of a new flow path that can reach shallow groundwater resources (or even the surface) is remote. The expected low permeability of faults in producible shale is clearly a limiting factor for the possible rupture length and seismic magnitude. In fact, for a fault that is initially nearly-impermeable, the only possibility of larger fault slip event would be opening by hydraulic fracturing; this would allow pressure to penetrate the matrix along the fault and to reduce the frictional strength over a sufficiently large fault surface patch. However, our simulation results show that if the fault is initially impermeable, hydraulic fracturing along the fault results in numerous small micro-seismic events along with the propagation, effectively

  6. Interpretation of Flow Logs from Nevada Test Site Boreholes to Estimate Hydraulic conductivity Using Numerical Simulations Constrained by Single-Well Aquifer Tests

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, C. Amanda; Halford, Keith J.; Laczniak, Randell J.


    Hydraulic conductivities of volcanic and carbonate lithologic units at the Nevada Test Site were estimated from flow logs and aquifer-test data. Borehole flow and drawdown were integrated and interpreted using a radial, axisymmetric flow model, AnalyzeHOLE. This integrated approach is used because complex well completions and heterogeneous aquifers and confining units produce vertical flow in the annular space and aquifers adjacent to the wellbore. AnalyzeHOLE simulates vertical flow, in addition to horizontal flow, which accounts for converging flow toward screen ends and diverging flow toward transmissive intervals. Simulated aquifers and confining units uniformly are subdivided by depth into intervals in which the hydraulic conductivity is estimated with the Parameter ESTimation (PEST) software. Between 50 and 150 hydraulic-conductivity parameters were estimated by minimizing weighted differences between simulated and measured flow and drawdown. Transmissivity estimates from single-well or multiple-well aquifer tests were used to constrain estimates of hydraulic conductivity. The distribution of hydraulic conductivity within each lithology had a minimum variance because estimates were constrained with Tikhonov regularization. AnalyzeHOLE simulated hydraulic-conductivity estimates for lithologic units across screened and cased intervals are as much as 100 times less than those estimated using proportional flow-log analyses applied across screened intervals only. Smaller estimates of hydraulic conductivity for individual lithologic units are simulated because sections of the unit behind cased intervals of the wellbore are not assumed to be impermeable, and therefore, can contribute flow to the wellbore. Simulated hydraulic-conductivity estimates vary by more than three orders of magnitude across a lithologic unit, indicating a high degree of heterogeneity in volcanic and carbonate-rock units. The higher water transmitting potential of carbonate-rock units relative

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

    Directory of Open Access Journals (Sweden)

    A. Storcheus


    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.

  8. Estimating the hydraulic parameters of a confined aquifer based on the response of groundwater levels to seismic Rayleigh waves (United States)

    Sun, Xiaolong; Xiang, Yang; Shi, Zheming


    Groundwater flow models implemented to manage regional water resources require aquifer hydraulic parameters. Traditional methods for obtaining these parameters include laboratory experiments, field tests, and model inversions, and each are potentially hindered by their unique limitations. Here, we propose a methodology for estimating hydraulic conductivity and storage coefficients using the spectral characteristics of the coseismic groundwater-level oscillations and seismic Rayleigh waves. The results from Well X10 are consistent with the variations and spectral characteristics of the water-level oscillations and seismic waves and present an estimated hydraulic conductivity of approximately 1 × 10-3 m/s and storativity of 15 × 10-6. The proposed methodology for estimating hydraulic parameters in confined aquifers is a practical and novel approach for groundwater management and seismic precursor anomaly analyses.

  9. Acoustic and Seismic Fields of Hydraulic Jumps at Varying Froude Numbers (United States)

    Ronan, Timothy J.; Lees, Jonathan M.; Mikesell, T. Dylan; Anderson, Jacob F.; Johnson, Jeffrey B.


    Mechanisms that produce seismic and acoustic wavefields near rivers are poorly understood because of a lack of observations relating temporally dependent river conditions to the near-river seismoacoustic fields. This controlled study at the Harry W. Morrison Dam (HWMD) on the Boise River, Idaho, explores how temporal variation in fluvial systems affects surrounding acoustic and seismic fields. Adjusting the configuration of the HWMD changed the river bathymetry and therefore the form of the standing wave below the dam. The HWMD was adjusted to generate four distinct wave regimes that were parameterized through their dimensionless Froude numbers (Fr) and observations of the ambient seismic and acoustic wavefields at the study site. To generate detectable and coherent signals, a standing wave must exceed a threshold Fr value of 1.7, where a nonbreaking undular jump turns into a breaking weak hydraulic jump. Hydrodynamic processes may partially control the spectral content of the seismic and acoustic energies. Furthermore, spectra related to reproducible wave conditions can be used to calibrate and verify fluvial seismic and acoustic models.

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

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


    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

  11. Formation of damage zone and seismic velocity variations during hydraulic stimulation: numerical modelling and field observations (United States)

    Shalev, Eyal; Calò, Marco; Lyakhovsky, Vladimir


    During hydraulic stimulations, a complex interaction is observed between the injected flux and pressure, number and magnitude of induced seismic events, and changes in seismic velocities. In this paper, we model formation and propagation of damage zones and seismicity patterns induced by wellbore fluid injection. The model includes the coupling of poroelastic deformation and groundwater flow with damage evolution (weakening and healing) and its effect on the elastic and hydrologic parameters of crystalline rocks. Results show that three subsequent interactions occur during stimulation. (1) Injected flux-pressure interaction: typically, after a flux increase, the wellbore pressure also rises to satisfy the flux conditions. Thereafter, the elevated pore pressure triggers damage accumulation and seismic activity, that is, accompanied by permeability increase. As a result, wellbore pressure decreases retaining the target injected flux. (2) Wellbore pressure-seismicity interaction: damage processes create an elongated damage zone in the direction close to the main principal stress. The rocks within the damage zone go through partial healing and remain in a medium damage state. Damage that originates around the injection well propagates within the damage zone away from the well, raising the damage state of the already damaged rocks, and is followed by compaction and fast partial healing back to a medium damage state. This `damage wave' behaviour is associated with the injected flux changes only in early stages while fracture's height (h) is larger than its length (l). The ratio h/l controls the deformation process that is responsible for several key features of the damage zone. (3) Stress- and damage-induced variations of the seismic P-wave velocities (Vp). Vp gradually decreases as damage is accumulated and increases after rock failure as the shear stress is released and healing and compaction are dominant. Typically, Vp decreases within the damage zone and increases in

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

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


    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Clochard, V.


    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)

  14. Relations of borehole resistivity to the horizontal hydraulic conductivity and dissolved-soils concentration in water of clastic coastal plain aquifers in the southeastern United States (United States)

    Faye, Robert E.; Smith, Winston G.


    Aquifer bulk resistivity and grain-surface resistivity (inverse of grain-surface conductance) were tested as geoelectrical analogs to the horizontal hydraulic conductivity of clastic, freshwater aquifers in the Southeastern United States. Bulk resistivity was also tested as a geoelectrical analog for dissolved-solids concentrations in aquifer water. Bulk resistivity was defined as the average resistivity across a contributing interval measured by the long-normal (64-inch) or induction log. Grain-surface resistivity was empirically defined as the difference between aquifer bulk resistivity and aquifer water resistivity (computed from specific conductance). Sources of data were borehole geophysical logs and results of water-quality and aquifer-test analyses related to unconsolidated sands and clayey sands at more than a hundred sites in seven Southeastern States. Waterbearing units were composed of sediments ranging from the Late Cretaceous to middle Eocene. All bivariate data were related using the logarithmic regression model Y=AX B. Aquifer bulk resistivity and grain-surface resistivity were moderately correlated to horizontal hydraulic conductivity (70 and 72 percent correlation coefficients, respectively). Apparent formation factor, defined as the ratio of aquifer bulk resistivity to aquifer water resistivity, was shown to be poorly correlated with horizontal hydraulic conductivity (38 percent correlation coefficient). Aquifer bulk resistivity was shown to be highly correlated with dissolved-solids concentration and aquifer water resistivity (88 and 93 percent correlation coefficients, respectively). Regression models using bulk resistivity and aquifer water resistivity as independent variables were applied at four locations in South Carolina and Louisiana to predict dissolved-solids concentrations in aquifer water. Absolute mean error of prediction was 20 and 6 percent, respectively. A regression model using bulk resistivity to predict horizontal hydraulic

  15. Change Detection via Cross-Borehole and VSP Seismic Surveys for the Source Physics Experiments (SPE) at the Nevada National Security Site (NNSS) (United States)

    Knox, H. A.; Abbott, R. E.; Bonal, N. D.; Aldridge, D. F.; Preston, L. A.; Ober, C.


    In support of the Source Physics Experiment (SPE) at the Nevada National Security Site (NNSS), we have conducted two cross-borehole seismic experiments in the Climax Stock. The first experiment was conducted prior to the third shot in this multi-detonation program using two available boreholes and the shot hole, while the second experiment was conducted after the shot using four of the available boreholes. The first study focused on developing a well-characterized 2D pre-explosion Vp model including two VSPs and a seismic refraction survey, as well as quantifying baseline waveform similarity at reoccupied sites. This was accomplished by recording both "sparker" and accelerated weight drop sources on a hydrophone string and surface geophones. In total more than 18,500 unique source-receiver pairs were acquired during this testing. In the second experiment, we reacquired aproximately 8,800 source-receiver pairs and performed a cross-line survey allowing for a 3D post-explosion Vp model. The data acquired from the reoccupied sites was processed using cross-correlation methods and change detection methodologies, including comparison of the tomographic images. The survey design and subsequent processing provided an opportunity to investigate seismic wave propagation through damaged rock. We also performed full waveform forward modelling for a granitic body hosting a perched aquifer. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  16. Experimental Investigations Regarding the Use of Sand as an Inhibitor of Air Convection in Deep Seismic Boreholes (United States)

    Holcomb, L. Gary; Sandoval, Leo; Hutt, Bob


    INTRODUCTION Tilt has been the nemesis of horizontal long period seismology since its inception. Modern horizontal long period seismometers with their long natural periods are incredibly sensitive to tilt. They can sense tilts smaller than 10 -11 radians. To most readers, this is just a very very small number, so we will begin with an example, which should help to illustrate just how small 10 -11 radians is. Suppose we have an absolutely rigid rod which is approximately 4170 kilometers long; this just happens to be the Rand McNally map scaled crow flight distance between Los Angeles and Boston. Tilting this rod 10 -11 radians corresponds to raising one end of the rod 0.0000417 meters. Alas, this is just another very very small number! However, this corresponds to slipping a little less than one third a sheet of ordinary copying paper under one end of this perfectly rigid rod. To clarify, we mean, take a sheet of paper just like the paper this report is printed on and split it a little less than one third in the thickness direction, then put it under the end of the 4170 kilometer long rod! This will tilt the rod 10 -11 radians. Real world seismometers are nowhere near the length of this rod. A KS-54000 is about two meters long. Tilting a rod only two meters long 10 -11 radians corresponds to moving one end of this rod a mere 0.00000000002 meters or 0.02 millimicrons. As one of the authors old math teachers used to say, 'That's PDS' (PDS = Pretty Damn Small). Unfortunately, the long period seismologist does not have the luxury of ignoring PDS numbers when it suits him as the mathematician frequently does. He must live in the real world in which tilts this small create severe contamination of long period seismic data. At periods longer than 20 seconds, tilt noise contaminates the long period data from all instruments installed on or near the earth's surface. Many years of experimentation revealed that installing the sensors at depth in deep mines drastically reduced

  17. Estimation of groundwater flow directions and the tensor of hydraulic conductivity in crystalline massif rocks using information from surface structural geology and mining exploration boreholes (United States)

    Florez, C.; Romero, M. A.; Ramirez, M. I.; Monsalve, G.


    In the elaboration of a hydrogeological conceptual model in regions of mining exploration where there is significant presence of crystalline massif rocks., the influence of physical and geometrical properties of rock discontinuities must be evaluated. We present the results of a structural analysis of rock discontinuities in a region of the Central Cordillera of Colombia (The upper and middle Bermellon Basin) in order to establish its hydrogeological characteristics for the improvement of the conceptual hydrogeological model for the region. The geology of the study area consists of schists with quartz and mica and porphyritic rocks, in a region of high slopes with a nearly 10 m thick weathered layer. The main objective of this research is to infer the preferential flow directions of groundwater and to estimate the tensor of potential hydraulic conductivity by using surface information and avoiding the use of wells and packer tests. The first step of our methodology is an analysis of drainage directions to detect patterns of structural controls in the run-off; after a field campaign of structural data recollection, where we compile information of strike, dip, continuity, spacing, roughness, aperture and frequency, we built equal area hydro-structural polar diagrams that indicate the potential directions for groundwater flow. These results are confronted with records of Rock Quality Designation (RQD) that have been systematically taken from several mining exploration boreholes in the area of study. By using all this information we estimate the potential tensor of hydraulic conductivity from a cubic law, obtaining the three principal directions with conductivities of the order of 10-5 and 10-6 m/s; the more conductive joint family has a NE strike with a nearly vertical dip.

  18. An analytical study on excitation of nuclear-coupled thermal-hydraulic instability due to seismically induced resonance in BWR

    Energy Technology Data Exchange (ETDEWEB)

    Hirano, Masashi [Japan Atomic Energy Research Institute, Ibaraki-ken (Japan)


    This paper describes the results of a scoping study on seismically induced resonance of nuclear-coupled thermal-hydraulic instability in BWRs, which was conducted by using TRAC-BF1 within a framework of a point kinetics model. As a result of the analysis, it is shown that a reactivity insertion could occur accompanied by in-surge of coolant into the core resulted from the excitation of the nuclear-coupled instability by the external acceleration. In order to analyze this phenomenon more in detail, it is necessary to couple a thermal-hydraulic code with a three-dimensional nuclear kinetics code.

  19. Seismic hydraulic fracture migration originated by successive deep magma pulses: The 2011-2013 seismic series associated to the volcanic activity of El Hierro Island (United States)

    Díaz-Moreno, A.; Ibáñez, J. M.; De Angelis, S.; García-Yeguas, A.; Prudencio, J.; Morales, J.; Tuvè, T.; García, L.


    In this manuscript we present a new interpretation of the seismic series that accompanied eruptive activity off the coast of El Hierro, Canary Islands, during 2011-2013. We estimated temporal variations of the Gutenberg-Richter b value throughout the period of analysis, and performed high-precision relocations of the preeruptive and syneruptive seismicity using a realistic 3-D velocity model. Our results suggest that eruptive activity and the accompanying seismicity were caused by repeated injections of magma from the mantle into the lower crust. These magma pulses occurred within a small and well-defined volume resulting in the emplacement of fresh magma along the crust-mantle boundary underneath El Hierro. We analyzed the distribution of earthquake hypocenters in time and space in order to assess seismic diffusivity in the lower crust. Our results suggest that very high earthquake rates underneath El Hierro represent the response of a stable lower crust to stress perturbations with pulsatory character, linked to the injection of magma from the mantle. Magma input from depth caused large stress perturbations to propagate into the lower crust generating energetic seismic swarms. The absence of any preferential alignment in the spatial pattern of seismicity reinforces our hypothesis that stress perturbation and related seismicity, had diffusive character. We conclude that the temporal and spatial evolution of seismicity was neither tracking the path of magma migration nor it defines the boundaries of magma storage volumes such as a midcrustal sill. Our conceptual model considers pulsatory magma injection from the upper mantle and its propagation along the Moho. We suggest, within this framework, that the spatial and temporal distributions of earthquake hypocenters reflect hydraulic fracturing processes associated with stress propagation due to magma movement.

  20. An efficient sequential strategy for realizing cross-gradient joint inversion: method and its application to two-dimensional cross borehole seismic travel time and DC resistivity tomography (United States)

    Gao, Ji; Zhang, Haijiang


    Cross-gradient joint inversion that enforces structural similarity between different models has been widely utilized in jointly inverting different geophysical data types. However, it is a challenge to combine different geophysical inversion systems with the cross-gradient structural constraint into one joint inversion system because they may differ greatly in the model representation, forward modeling, and inversion algorithm. Here we propose a new joint inversion strategy that can avoid this issue. Different models are separately inverted using the existing inversion packages and model structure similarity is only enforced through cross-gradient minimization between two models after each iteration. Although the data fitting and structure similarity enforcing processes are decoupled, our proposed strategy is still able to choose appropriate models to balance the trade-off between geophysical data fitting and structural similarity. This is realized by using model perturbations from separate data inversions to constrain the cross-gradient minimization process. We have tested this new strategy on two-dimensional cross borehole synthetic seismic travel time and DC resistivity datasets. Compared to separate geophysical inversions, our proposed joint inversion strategy fits the separate data sets at comparable levels while at the same time resulting in a higher structural similarity between the velocity and resistivity models.

  1. Stratigraphy of a proposed wind farm site southeast of Block Island: Utilization of borehole samples, downhole logging, and seismic profiles (United States)

    Sheldon, Dane P. H.

    Seismic stratigraphy, sedimentology, lithostratigraphy, downhole geophysical logging, mineralogy, and palynology were used to study and interpret the upper 70 meters of the inner continental shelf sediments within a proposed wind farm site located approximately two to three nautical miles to the southeast of Block Island, Rhode Island. Core samples and downhole logging collected from borings drilled for geotechnical purposes at proposed wind turbine sites along with seismic surveys in the surrounding area provide the data for this study. Cretaceous coastal plain sediments that consist of non-marine to marine sand, silt, and clay are found overlying bedrock at a contact depth beyond the sampling depth of this study. The upper Cretaceous sediments sampled in borings are correlated with the Magothy/Matawan formations described regionally from New Jersey to Nantucket. An unconformity formed through sub-aerial, fluvial, marine, and glacial erosion marks the upper strata of the Cretaceous sediments separating them from the overlying deposits. The majority of Quaternary deposits overlying the unconformity represent the advance, pulsing, and retreat of the Laurentide ice sheet that reached its southern terminus in the area of Block Island approximately 25,000 to 21,000 years before present. The sequence consists of a basal glacial till overlain by sediments deposited by meltwater environments ranging from deltaic to proglacial lakefloor. A late Pleistocene to early Holocene unconformity marks the top of the glacial sequence and was formed after glacial retreat through fluvial and subaerial erosion/deposition. Overlying the glacial sequence are sediments deposited during the late Pleistocene and Holocene consisting of interbedded gravel, sand, silt, and clay. Sampling of these sediments was limited and surficial reflectors in seismic profiles were masked due to a hard bottom return. However, two depositional periods are interpreted as representing fluvial and estuarine

  2. Seismic Proofing Capability of the Accumulated Semiactive Hydraulic Damper as an Active Interaction Control Device with Predictive Control

    Directory of Open Access Journals (Sweden)

    Ming-Hsiang Shih


    Full Text Available The intensity of natural disasters has increased recently, causing buildings’ damages which need to be reinforced to prevent their destruction. To improve the seismic proofing capability of Accumulated Semiactive Hydraulic Damper, it is converted to an Active Interaction Control device and synchronous control and predictive control methods are proposed. The full-scale shaking table test is used to test and verify the seismic proofing capability of the proposed AIC with these control methods. This study examines the shock absorption of test structure under excitation by external forces, influences of prediction time, stiffness of the auxiliary structure, synchronous switching, and asynchronous switching on the control effects, and the influence of control locations of test structure on the control effects of the proposed AIC. Test results show that, for the proposed AIC with synchronous control and predictive control of 0.10~0.13 seconds, the displacement reduction ratios are greater than 71%, the average acceleration reduction ratios are, respectively, 36.2% and 36.9%, at the 1st and 2nd floors, and the average base shear reduction ratio is 29.6%. The proposed AIC with suitable stiffeners for the auxiliary structure at each floor with synchronous control and predictive control provide high reliability and practicability for seismic proofing of buildings.

  3. Borehole Data (United States)

    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...

  4. Engineering and Design: Response Spectra and Seismic Analysis for Concrete Hydraulic Structures

    National Research Council Canada - National Science Library


    .... The manual provides guidance regarding how earthquake ground motions are characterized as design response spectra and how they are then used in the process of seismic structural analysis and design...

  5. A borehole jack for deformability, strength, and stress measurements in a 2-inch borehole (United States)

    Goodman, R. E.; Hovland, H. J.; Chirapuntu, S.


    A borehole jack devised for lunar exploration is described and results of its use in simulated lunar solids are presented. A hydraulic cylinder mounted between two stiff plates acts to spread the plates apart against the borehole walls when pressured. The spreading is measured by a displacement transducer and the load is measured hydraulically. The main improvement over previous instruments is the increased stroke, which allows large deformations of the borehole. Twenty-eight pistons are used to obtain a high hydraulic efficiency, and three return pistons are also provided. Pressure-deformation curves were obtained for each test on Lunar Soil Simulant No. 2, a light gray silty basalt powder.

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

    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.


    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

  7. Myths and facts on wastewater injection, hydraulic fracturing, enhanced oil recovery, and induced seismicity (United States)

    Rubinstein, Justin L.; Mahani, Alireza Babaie


    The central United States has undergone a dramatic increase in seismicity over the past 6 years (Fig. 1), rising from an average of 24 M≥3 earthquakes per year in the years 1973–2008 to an average of 193 M≥3 earthquakes in 2009–2014, with 688 occurring in 2014 alone. Multiple damaging earthquakes have occurred during this increase including the 2011 M 5.6 Prague, Oklahoma, earthquake; the 2011 M 5.3 Trinidad, Colorado, earthquake; and the 2011M 4.7 Guy‐Greenbrier, Arkansas, earthquake. The increased seismicity is limited to a few areas and the evidence is mounting that the seismicity in many of these locations is induced by the deep injection of fluids from nearby oil and gas operations. Earthquakes that are caused by human activities are known as induced earthquakes. Most injection operations, though, do not appear to induce earthquakes. Although the message that these earthquakes are induced by fluid injection related to oil and gas production has been communicated clearly, there remains confusion in the popular press beyond this basic level of understanding.

  8. Correlation of Hydraulic Fracturing Induced Seismicity with Operation Parameters of Shale Gas Extraction: Two Case Studies in Western Canada (United States)

    Farahbod, A. M.; Kao, H.; Cassidy, J. F.; Snyder, D. B.; Cairns, S.; Walker, D.


    Northeast British Columbia, specifically the Horn River Basin (HRB) and Montney Trend, are among the largest shale gas production regions in western Canada. In contrast, there has been no large-scale hydraulic fracturing (HF) operation in the Northwest Territories in the Norman Wells region of the central Mackenzie valley. In this study, we investigate the effect of injection pressure, operation duration and injected volume on the observed seismicity in the HRB and Norman Wells regions and compare our observations with the pre-HF records. In the HRB, we apply the single-station location and waveform correlation methods to establish a homogenous earthquake catalog (2006/12-2011/12). In the Northwest Territories, we combine data from a local seismograph network of 4 stations plus a dense array of 7 stations located from 1 km to 50 km from the operation wells to locate earthquakes (2013/09-2014/07). In the HRB, the initial effect of an increased injected volume is an increase in earthquake frequency but not magnitude. Local earthquakes gradually become larger in magnitude as the scale of HF in the region expands. While the injection pressure during HF operations has been regulated at a relatively constant level, the massive increase of injection volume in 2010 and 2011 coincides with a series of ML>3 events. Relatively large seismic moment release (>1014 N m) occurred only when the monthly injected volume exceeded ~150,000 m3. In addition, we observe variable time lags, from days to up to 4 months between intense HF and the occurrence of a significant local earthquake. On the other hand, in the Norman Wells region, two small-scale HF were performed in 2014 with a total injected volume of ~ 14000 m3. We observed an increase in the number of micro-earthquakes (M < 2.0) during the HF period without a clear change in the overall seismic pattern. From these two observations, we conclude that HF operations do not necessarily result in an increase in the occurrence rate of

  9. Design and Operation of a Borehole Straddle Packer for Ground-Water Sampling and Hydraulic Testing of Discrete Intervals at U.S. Air Force Plant 6, Marietta, Georgia (United States)

    Holloway, Owen G.; Waddell, Jonathan P.


    A borehole straddle packer was developed and tested by the U.S. Geological Survey to characterize the vertical distribution of contaminants, head, and hydraulic properties in open-borehole wells as part of an ongoing investigation of ground-water contamination at U.S. Air Force Plant 6 (AFP6) in Marietta, Georgia. To better understand contaminant fate and transport in a crystalline bedrock setting and to support remedial activities at AFP6, numerous wells have been constructed that include long open-hole intervals in the crystalline bedrock. These wells can include several discontinuities that produce water, which may contain contaminants. Because of the complexity of ground-water flow and contaminant movement in the crystalline bedrock, it is important to characterize the hydraulic and water-quality characteristics of discrete intervals in these wells. The straddle packer facilitates ground-water sampling and hydraulic testing of discrete intervals, and delivery of fluids including tracer suites and remedial agents into these discontinuities. The straddle packer consists of two inflatable packers, a dual-pump system, a pressure-sensing system, and an aqueous injection system. Tests were conducted to assess the accuracy of the pressure-sensing systems, and water samples were collected for analysis of volatile organic compound (VOCs) concentrations. Pressure-transducer readings matched computed water-column height, with a coefficient of determination of greater than 0.99. The straddle packer incorporates both an air-driven piston pump and a variable-frequency, electronic, submersible pump. Only slight differences were observed between VOC concentrations in samples collected using the two different types of sampling pumps during two sampling events in July and August 2005. A test conducted to assess the effect of stagnation on VOC concentrations in water trapped in the system's pump-tubing reel showed that concentrations were not affected. A comparison was conducted

  10. Electromagnetic Monitoring of Hydraulic Fracturing: Relationship to Permeability, Seismicity, and Stress (United States)

    Thiel, Stephan


    Hydraulic fracking is a geoengineering application designed to enhance subsurface permeability to maximize fluid and gas flow. Fracking is commonly used in enhanced geothermal systems (EGS), tight shale gas, and coal seam gas (CSG) plays and in CO_2 storage scenarios. Common monitoring methods include microseismics and mapping small earthquakes with great resolution associated with fracture opening at reservoir depth. Recently, electromagnetic (EM) methods have been employed in the field to provide an alternative way of direct detection of fluids as they are pumped in the ground. Surface magnetotelluric (MT) measurements across EGS show subtle yet detectable changes during fracking derived from time-lapse MT deployments. Changes are directional and are predominantly aligned with current stress field, dictating preferential fracture orientation, supported by microseismic monitoring of frack-related earthquakes. Modeling studies prior to the injection are crucial for survey design and feasibility of monitoring fracks. In particular, knowledge of sediment thickness plays a fundamental role in resolving subtle changes. Numerical forward modeling studies clearly favor some form of downhole measurement to enhance sensitivity; however, these have yet to be conclusively demonstrated in the field. Nevertheless, real surface-based monitoring examples do not necessarily replicate the expected magnitude of change derived from forward modeling and are larger than expected in some cases from EGS and CSG systems. It appears the injected fluid volume alone cannot account for the surface change in resistivity, but connectedness of pore space is also significantly enhanced and nonlinear. Recent numerical studies emphasize the importance of percolation threshold of the fracture network on both electrical resistivity and permeability, which may play an important role in accounting for temporal changes in surface EM measurements during hydraulic fracking.

  11. Characterizing fractures and shear zones in crystalline rock using seismic and GPR methods (United States)

    Doetsch, Joseph; Jordi, Claudio; Laaksonlaita, Niko; Gischig, Valentin; Schmelzbach, Cedric; Maurer, Hansruedi


    Understanding the natural or artificially created hydraulic conductivity of a rock mass is critical for the successful exploitation of enhanced geothermal systems (EGS). The hydraulic response of fractured crystalline rock is largely governed by the spatial organization of permeable fractures. Defining the 3D geometry of these fractures and their connectivity is extremely challenging, because fractures can only be observed directly at their intersections with tunnels or boreholes. Borehole-based and tunnel-based ground-penetrating radar (GPR) and seismic measurements have the potential to image fractures and other heterogeneities between and around boreholes and tunnels, and to monitor subtle time-lapse changes in great detail. We present the analysis of data acquired in the Grimsel rock laboratory as part of the In-situ Stimulation and Circulation (ISC) experiment, in which a series of stimulation experiments have been and will be performed. The experiments in the granitic rock range from hydraulic fracturing to controlled fault-slip experiments. The aim is to obtain a better understanding of coupled seismo-hydro-mechanical processes associated with high-pressure fluid injections in crystalline rocks and their impact on permeability creation and enhancement. GPR and seismic data have been recorded to improve the geological model and characterize permeable fractures and shear zones. The acquired and processed data include reflection GPR profiles measured from tunnel walls, single-borehole GPR images, and borehole-to-borehole and tunnel-to-tunnel seismic and GPR tomograms. The reflection GPR data reveal the geometry of shear zones up to a distance of 30 m from the tunnels and boreholes, but the interpretation is complicated by the geometrical ambiguity around tunnels and boreholes and by spurious reflections from man-made structures such as boreholes. The GPR and seismic traveltime tomography results reveal brittle fractured rock between two ductile shear zones. The

  12. Structure and Stratigraphy of the Rift Basins in the Northern Gulf of California: Results from Analysis of Seismic Reflection and Borehole Data. (United States)

    Martín, A.; González, M.; Helenes, J.; García, J.; Aragón, M.; Carreño, A.


    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

  13. Monitoring borehole flow dynamics using heated fiber optic DTS in a fractured rock aquifer (United States)

    Coleman, Thomas; Chalari, Athena; Parker, Beth; Munn, Jonathan; Mondanos, Michael


    Temperature profiles in fractured rock have long been used to identify and characterize flow in the rock formation or in the borehole. Fiber optic distributed temperature sensing (DTS) is a tool that allows for continuous borehole temperature profiling in space and time. Recent technology advancements in the spatial, temperature, and temporal resolutions of DTS systems now allow temperature profiling methods to offer improved insight into fractured rock hydrogeologic processes. An innovation in shallow borehole temperature logging utilizes high resolution DTS temperature profiling in sealed and heated boreholes to identify fractures with natural gradient groundwater flow by creating a thermal disequilibrium and monitoring the temperature response. This technique can also be applied to open well conditions to monitor borehole flow distributions caused by hydraulic perturbations such as pumping or injection. A field trial was conducted in Guelph, Ontario, Canada to determine the capabilities of heated DTS for flow monitoring in both open and sealed wells. Intelligent distributed acoustic sensing (iDAS) measurements for vertical seismic profiling were carried out simultaneously with the DTS measurements to assist with characterization of the fractured aquifer system. DTS heat pulse tests were conducted in a single well under sealed conditions for natural gradient flow measurements and open conditions to monitor flow distributions during injection and pumping. The results of these tests indicate that borehole flow distributions can be monitored using DTS and that active heating allows for further information about the hydrogeologic system to be determined than from the passive measurements alone. Depth-continuous transmissivity data from the borehole correlate well with the DTS testing results. DTS based flow monitoring systems may be useful for monitoring transient production and injection processes for a variety of applications including groundwater remediation

  14. Development of a thermal hydraulic modelling of ground water of the Malm in the Munich metropolitan area; Entwicklung einer thermisch-hydraulischen Grundwassermodellierung des Malm im Grossraum Muenchen

    Energy Technology Data Exchange (ETDEWEB)

    Dussel, M.; Lueschen, E.; Thomas, R. [Leibniz-Institut fuer Angewandte Geophysik, Hannover (DE)] (and others)


    The mutual potential influence of geothermal duplicates and the scientific investigation of the relationship between seismic and hydraulic parameters are investigated in the joint research project 'Geothermal characterization of fractured karst limestone aquifers in the Munich metropolitan area'. Thirteen doublets and triplets being in production or sunk illustrate the great geothermal potential and provide important data on the development of a thermal-hydraulic modeling of the reservoir. 3D seismic Unterhaching, 3D structural model, hydrogeological model and a high-resolution 3D temperature model form the basis of the numerical modeling. Different seismic signatures, seismic attributes and variations in the interval velocities characterize the ground geophysically, and were interpreted under consideration of geological and hydrogeological background information as well as borehole measurements in terms of hydraulically conductive homogeneous areas. For the Munich metropolitan area, the numerical modeling is a decision aid for the future optimized and sustainable hydrothermal utilization of the Malm aquifer.

  15. Characterization and interpretation of a fractured rocky massif from borehole data. Boreholes of geothermal project at Soultz-sous-Forets and other examples of unidirectional sampling; Caracterisation et interpretation d`un volume rocheux fracture a partir de donnees de forages. Les forages geothermiques de Soultz-sous-Forets et autres exemples d`echantillonnages unidirectionnels

    Energy Technology Data Exchange (ETDEWEB)

    Dezayes, CH.


    In this thesis, we study fractures from borehole data on two sites: in one, located at Soultz-sous-Forets (Alsace) in the Rhine graben, boreholes reach a delta Jurassic series forming a petroleum reservoir. At Soultz, fractures have been studied on cores and borehole images. Striated faults present on cores permit to determine the tectonic history of the granite, completed by field study in Vosges Massif. This history corresponds to the Rhine graben history knowing by different authors. The analysis of vertical induced fractures observed on borehole images indicates a present-day NW-SE to NNW-SSE compression. These variations of stress direction are confirmed by others in situ measurements, as hydraulic injection, micro-seismicity, etc... On cores and borehole images, numerous fractures have been observed. Most of them are linked to the E-W distension, which permits the Rhine graben opening at Oligocene. At greatest scale, in quartz minerals, the micro-fractures are constitute by fluid inclusion trails. Several sets are related to the E-W distension, but others sets are linked to compressive stages. These sets are not observed on cores. This is a under-sampling of some fractures by the boreholes, but theses fractures exit into to rock massif. On borehole images, fracture density is weakest than the cores, however the set organisation is the same. At Ravenscar, the distribution of fracture spacing along different unidirectional sampling shows a exponential negative law. However, the fracture density varies with sampling. (author) 199 refs.

  16. Deep structure and crustal configuration of the Jeffara basin (Southern Tunisia) based on regional gravity, seismic reflection and borehole data: How to explain a gravity maximum within a large sedimentary basin? (United States)

    Gabtni, H.; Jallouli, C.; Mickus, K. L.; Zouari, H.; Turki, M. M.


    The Jeffara basin of southern Tunisia contains a thick sequence of mainly Triassic and Permian sediments that is characterized by a gravity maximum. To explain the positive gravity signature over the Jeffara sedimentary basin and to obtain a more quantitative representation of the subsurface structure, a regional 2.5D gravity model constrained by seismic reflection and borehole data was constructed along a NE-SW trending profile. The depth to the crust/mantle implies that the Jeffara basin is associated with crustal thinning. The gravity model also implies that subsidence is controlled by a basement stepped down by relatively low-displacement faulting. This sedimentary subsidence, as described by a listric-faulting model, is probably caused by a thinned crust.

  17. High-temperature borehole instrumentation (United States)

    Dennis, B. R.; Koczan, S. P.; Stephani, E. L.


    A new method of extracting natural heat from the Earth's crust was invented at the Los Alamos National Laboratory in 1970. It uses fluid pressures (hydraulic fracturing) to produce cracks that connect two boreholes drilled into hot rock formations of low initial permeability. Pressurized water is then circulated through this connected underground loop to extract heat from the rock and bring it to the surface. The creation of the fracture reservior began with drilling boreholes deep within the Precambrian basement rock at the Fenton Hill Test Site. Hydraulic fracturing, flow testing, and well-completion operations required unique wellbore measurements using downhole instrumentation systems that would survive the very high borehole temperatures, 320(0)C (610(0)F). These instruments were not available in the oil and gas industrial complex, so the Los Alamos National Laboratory initiated an intense program upgrading existing technology where applicable, subcontracting materials and equipment development to industrial manufactures, and using the Laboratory resources to develop the necessary downhole instruments to meet programmatic schedules.

  18. Structural and Depositional Evolution of the Stevenson Basin, a Gulf of Alaska Forearc Basin: Insights from Legacy Seismic and Borehole Data (United States)

    Bhattacharya, R.; Liberty, L. M.; Almeida, R. V.; Hubbard, J.


    We explore the structural and depositional evolution of the Stevenson Basin, Gulf of Alaska from a dense network of 2-D marine seismic profiles that span the Gulf of Alaska continental margin. The grid of 71 seismic profiles was acquired as part of a 1975 Mineral Management Services (MMS) exploration project to assess basin architecture along the Alaska continental shelf. We obtained unmigrated and stacked seismic profiles in TIFF format. We converted the data to SEGY format and migrated each profile. Within the Stevenson Basin, we identify key seismic horizons, including the regional Eocene-Miocene unconformity, that provide insights into its depositional and structural history. Using these observations combined with stacking velocities, sonic logs from wells, and refraction velocities from the Edge profile of Ye et al. (1997), we develop a local 3D velocity model that we use to depth-convert the seismic reflection profiles. By using ties to >2.5 km deep exploration wells, we note the Stevenson Basin is one of many Eocene and younger depocenters that span the forearc between Kodiak and Prince William Sound. Well logs and seismic data suggest basal strata consist of Eocene sediments than are unconformably overlain by Neogene and younger strata. Faults that breach the sea floor suggest active deformation within and at the bounds of this basin, including on new faults that do not follow any pre-existing structural trends. This assessment is consistent with slip models that place tsunamigenic faults that ruptured during the 1964 Great Alaska earthquake in the vicinity of the basin. The catalog of faults, their slip history and the depositional evolution of the Stevenson Basin, all suggest that the basin evolution may be controlled by heterogeneities along the incoming plate.

  19. Seismic wave attenuation from borehole and surface records in the top 2.5 km beneath the city of Basel, Switzerland

    KAUST Repository

    Bethmann, Falko


    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.

  20. The Ventersdorp Contact Reef model in the Kloof Gold Mine as derived from 3D seismics, geological mapping and exploration borehole datasets

    CSIR Research Space (South Africa)

    Manzi, MSD


    Full Text Available geometric model of the VCR orebody and its offsets. The underground mapping datasets help to define minor faults and dikes that are below seismic resolution limits. The integration of the these datasets allowed (1) for better mapping of fault architectures...

  1. Permeability Enhancement in Enhanced Geothermal System as a result of Hydraulic Fracturing and Jacking (United States)

    Jalali, Mohammadreza; Klepikova, Maria; Fisch, Hansruedi; Amann, Florian; Loew, Simon


    A decameter-scale in-situ hydraulic stimulation and circulation (ISC) experiment has been initiated by the newly-founded Swiss Competence Centre for Energy Research - Supply of Electricity (SCCER-SoE) at Nagra's Grimsel Test Site (GTS) as a part of the work-package WP1 of the Deep Underground Laboratory (DUG-Lab) initiative. The experiment area is situated in the southern part of the GTS in a low fracture density volume of the Grimsel granodiorite. The hydraulic properties of the granitic rock mass are supposed to be similar to those expected in the crystalline basement of the alpine foreland where deep enhanced geothermal systems might be developed in future. The main objectives of the multi-disciplinary experiment are to provide a high resolution pre- and post-stimulation characterization of fracture permeability and connectivity, to investigate patterns of preferential flow paths, to describe the pressure propagation during the stimulation phases and to evaluate the efficiency of the fracture-matrix heat exchanger. A comprehensive test & monitoring layout including a fair number of boreholes instrumented with a variety of sensors (e.g. pressure, strain, displacement, temperature, and seismic sensors) is designed to collect detailed data during multiple hydraulic stimulation runs. The diffusion of fluid pressure is expected to be governed mainly by the properties and geometry of the existent fracture network. The hydraulic transmissivity of fractures are in the range of 10-7 to 10-9 m2/s whereas the matrix rock has a very low hydraulic conductivity (K ˜ 10-12 m/s). As part of the stress measurement campaign during the pre-stimulation phase of the ISC experiment, a series of hydraulic fracturing (HF) and hydraulic tests in pre-existing fractures (HTPF) were conducted. The tests were accompanied by micro-seismic monitoring within several observation boreholes to investigate the initiation and propagation of the induced fractures. Together with results from over

  2. Borehole Muon Detector Development (United States)

    Bonneville, A.; Flygare, J.; Kouzes, R.; Lintereur, A.; Yamaoka, J. A. K.; Varner, G. S.


    Increasing atmospheric CO2 concentrations have spurred investigation into carbon sequestration methods. One of the possibilities being considered, storing super-critical CO2 in underground reservoirs, has drawn more attention and pilot projects are being supported worldwide. Monitoring of the post-injection fate of CO2 is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We propose here to develop a 4-D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Muon detection is a relatively mature field of particle physics and there are many muon detector designs, though most are quite large and not designed for subsurface measurements. The primary technical challenge preventing deployment of this technology in the subsurface is the lack of miniaturized muon-tracking detectors capable of fitting in standard boreholes and that will resist the harsh underground conditions. A detector with these capabilities is being developed by a collaboration supported by the U.S. Department of Energy. Current simulations based on a Monte Carlo modeling code predict that the incoming muon angle can be resolved with an error of approximately two degrees, using either underground or sea level spectra. The robustness of the design comes primarily from the use of scintillating rods as opposed to drift tubes. The rods are arrayed in alternating layers to provide a coordinate scheme. Preliminary testing and measurements are currently being performed to test and enhance the performance of the scintillating rods, in both a laboratory and a shallow underground facility. The simulation predictions and data from the experiments will be presented.

  3. Experimental research on sealing of boreholes, shafts and ramps in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Fuenkajorn, K. [Rock Engineering International, Tucson, AZ (United States)


    Laboratory and in-situ experiments have been conducted to determine the mechanical and hydraulic performance of cement borehole seals in densely welded Apache Leap tuff. Test results indicate that under saturated conditions, commercial expansive cement can provide good bond strength and adequate hydraulic performance for borehole seal under changing stress conditions. The cement seal should be installed at the intact portion of the opening, and should have a length-to-diameter ratio greater than four. Drying increases borehole plug permeability and decreases mechanical and hydraulic bonds at the plug-rock interface. In-situ testing indicates that installation procedure may significantly affect the cement plug performance.

  4. New developments in high resolution borehole seismology and their applications to reservoir development and management

    Energy Technology Data Exchange (ETDEWEB)

    Paulsson, B.N.P. [Chevron Petroleum Technology Company, La Habra, CA (United States)


    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.

  5. Reservoir Stimulation Experiments at the Grimsel Test Site: Stress Measurements using Hydraulic fracturing, Hydraulic Tests on Pre-existing Fractures and Overcoring (United States)

    Doetsch, J.; Gischig, V.; Amann, F.; Madonna, C.; Jalali, M.; Valley, B.; Evans, K. F.


    A decameter-scale in-situ hydraulic stimulation and circulation experiment has been planned in the Deep Underground rock Laboratory (DUG Lab) at the Grimsel Test Site, Switzerland. The general objective of this experiment is to improve our understanding of the pressure, temperature and stress changes in the rock mass due to hydraulic stimulation. In this context, the main goal is to investigate the effect of hydro-shearing on the local stress variation as well as transient and permanent permeability changes with comprehensive thermo-hydro-mechanical (THM) and acoustic emission monitoring. This experiment is designed such that stimulation processes are recorded in a dataset that is unique in THM coupled processes and induced seismicity research. In preparation to the hydro-shearing experiments, the experimental rock volume has been studied in detail using geological tunnel mapping, optical televiewer in existing boreholes, hydraulic tests, geophysical imaging and review of the extensive literature on experiments at the Grimsel Test Site. The geophysical investigations include reflection and transmission ground penetrating radar (GPR) and seismic measurements between the tunnels to image shear zones and reveal heterogeneity of the rock mass. The orientation and magnitude of the principal stresses of the rock volume and its surroundings has been analyzed using hydraulic fracturing, hydraulic tests on pre-existing fractures and overcoring. The hydraulic fracturing tests for stress measurements were monitored using a 32-channel acoustic emission monitoring system and a regional seismic monitoring network. Here, we present the results of the pre-investigations and stress measurements, and give an outlook for the hydro-shearing experiments planned for spring 2016.

  6. Permeability, storage and hydraulic diffusivity controlled by earthquakes (United States)

    Brodsky, E. E.; Fulton, P. M.; Xue, L.


    Earthquakes can increase permeability in fractured rocks. In the farfield, such permeability increases are attributed to seismic waves and can last for months after the initial earthquake. Laboratory studies suggest that unclogging of fractures by the transient flow driven by seismic waves is a viable mechanism. These dynamic permeability increases may contribute to permeability enhancement in the seismic clouds accompanying hydraulic fracking. Permeability enhancement by seismic waves could potentially be engineered and the experiments suggest the process will be most effective at a preferred frequency. We have recently observed similar processes inside active fault zones after major earthquakes. A borehole observatory in the fault that generated the M9.0 2011 Tohoku earthquake reveals a sequence of temperature pulses during the secondary aftershock sequence of an M7.3 aftershock. The pulses are attributed to fluid advection by a flow through a zone of transiently increased permeability. Directly after the M7.3 earthquake, the newly damaged fault zone is highly susceptible to further permeability enhancement, but ultimately heals within a month and becomes no longer as sensitive. The observation suggests that the newly damaged fault zone is more prone to fluid pulsing than would be expected based on the long-term permeability structure. Even longer term healing is seen inside the fault zone of the 2008 M7.9 Wenchuan earthquake. The competition between damage and healing (or clogging and unclogging) results in dynamically controlled permeability, storage and hydraulic diffusivity. Recent measurements of in situ fault zone architecture at the 1-10 meter scale suggest that active fault zones often have hydraulic diffusivities near 10-2 m2/s. This uniformity is true even within the damage zone of the San Andreas fault where permeability and storage increases balance each other to achieve this value of diffusivity over a 400 m wide region. We speculate that fault zones

  7. Intermediate-Scale Hydraulic Fracturing in a Deep Mine - kISMET Project Summary 2016

    Energy Technology Data Exchange (ETDEWEB)

    Oldenburg, C. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dobson, P. F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wu, Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Cook, P. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kneafsey, T. J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nakagawa, S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ulrich, C. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Siler, D. L. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Guglielmi, Y. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ajo-Franklin, J. B. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, J. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Daley, T. M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, J. T. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Wang, H. F. [Univ. of Wisconsin, Madison, WI (United States); Lord, N. E. [Univ. of Wisconsin, Madison, WI (United States); Haimson, B. C. [Univ. of Wisconsin, Madison, WI (United States); Sone, H. [Univ. of Wisconsin, Madison, WI (United States); Vigilante, P. [Univ. of Wisconsin, Madison, WI (United States); Roggenthen, W. M. [South Dakota School of Mines and Technology, Rapid City, SD (United States); Doe, T. W. [Golder Associates Inc., Toronto, ON (Canada); Lee, M. Y. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Ingraham, M. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Huang, H. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mattson, E. D. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Zhou, J. [Idaho National Lab. (INL), Idaho Falls, ID (United States); Johnson, T. J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Morris, J. P. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); White, J. A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Johnson, P. A. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Coblentz, D. D. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Heise, J. [Stanford Underground Research Facility, Lead, SD (United States); Zoback, M. D. [Stanford Univ., CA (United States)


    In support of the U.S. DOE SubTER Crosscut initiative, we established a field test facility in a deep mine and designed and carried out in situ hydraulic fracturing experiments in the crystalline rock at the site to characterize the stress field, understand the effects of rock fabric on fracturing, and gain experience in monitoring using geophysical methods. The project also included pre- and post-fracturing simulation and analysis, laboratory measurements and experiments, and we conducted an extended analysis of the local stress state using previously collected data. Some of these activities are still ongoing. The kISMET (permeability (k) and Induced Seismicity Management for Energy Technologies) experiments meet objectives in SubTER’s “stress” pillar and the “new subsurface signals” pillar. The kISMET site was established in the West Access Drift of SURF 4850 ft (1478 m) below ground (on the 4850L) in phyllite of the Precambrian Poorman Formation. We drilled and cored five near-vertical boreholes in a line on 3 m spacing, deviating the two outermost boreholes slightly to create a five-spot pattern around the test borehole centered in the test volume at ~1528 m (5013 ft). Laboratory measurements of core from the center test borehole showed P-wave velocity heterogeneity along each core indicating strong, fine-scale (~1 cm or smaller) changes in the mechanical properties of the rock. The load-displacement record on the core suggests that the elastic stiffness is anisotropic. Tensile strength ranges between 3-7.5 MPa and 5-12 MPa. Permeability measurements are planned, as are two types of laboratory miniature hydraulic fracturing experiments to investigate the importance of rock fabric (anisotropy and heterogeneity) on near-borehole hydraulic fracture generation. Pre-fracturing numerical simulations with INL’s FALCON discrete element code predicted a fracture radius of 1.2 m for a corresponding injection volume of 1.2 L for the planned fractures, and

  8. Characterizing fractures and shear zones in crystalline rock using anisotropic seismic inversion and GPR imaging (United States)

    Doetsch, Joseph; Krietsch, Hannes; Lajaunie, Myriam; Jordi, Claudio; Gischig, Valentin; Schmelzbach, Cedric; Maurer, Hansrudi


    Understanding the natural or artificially created hydraulic conductivity of a rock mass is critical for the successful exploitation of enhanced geothermal systems (EGS). The hydraulic response of fractured crystalline rock is largely governed by the spatial organization of permeable fractures. Defining the 3D geometry of these fractures and their connectivity is extremely challenging, because fractures can only be observed directly at their intersections with tunnels or boreholes. In the framework of an in-situ stimulation experiment at the Grimsel Test Site, a detailed rock mass characterization was carried out, combining geological and geophysical methods. While geological observations from tunnel mapping, core- and geophysical borehole-logging are reliable, the obtained data could just be interpolated between tunnels and boreholes. The geophysical surveys, including ground-penetration radar (GPR) imaging and tunnel-tunnel seismic tomography were able to image shear and fracture zones throughout the experimental volume. Clear GPR reflections up to a distance of 30 m from the tunnels allow to define the geometry of tunnel-mapped shear zones in the center of the experimental volume. Anisotropic traveltime inversion of tunnel-tunnel seismic data reveals fracture zones as low velocity zones and ductile shear zones as areas of increased seismic anisotropy. It is thus possible to characterize both type and geometry of shear and fracture zones, which is important for the planned rock stimulation. Combining the GPR and seismic results with the geological information, the geological model could be significantly improved, demonstrating the potential to characterize even subtle geological features in 3D.

  9. Deep boreholes; Tiefe Bohrloecher

    Energy Technology Data Exchange (ETDEWEB)

    Bracke, Guido [Gesellschaft fuer Anlagen- und Reaktorsicherheit gGmbH Koeln (Germany); Charlier, Frank [NSE international nuclear safety engineering gmbh, Aachen (Germany); Geckeis, Horst [Karlsruher Institut fuer Technologie (Germany). Inst. fuer Nukleare Entsorgung; and others


    The report on deep boreholes covers the following subject areas: methods for safe enclosure of radioactive wastes, requirements concerning the geological conditions of possible boreholes, reversibility of decisions and retrievability, status of drilling technology. The introduction covers national and international activities. Further chapters deal with the following issues: basic concept of the storage in deep bore holes, status of the drilling technology, safe enclosure, geomechanics and stability, reversibility of decisions, risk scenarios, compliancy with safe4ty requirements and site selection criteria, research and development demand.

  10. Fluid Induced Earthquakes: From KTB Experiments to Natural Seismicity Swarms. (United States)

    Shapiro, S. A.


    Experiments with borehole fluid injections are typical for exploration and development of hydrocarbon or geothermal reservoirs (e.g., fluid-injection experiments at Soultz, France and at Fenton-Hill, USA). Microseismicity occurring during such operations has a large potential for understanding physics of the seismogenic process as well as for obtaining detailed information about reservoirs at locations as far as several kilometers from boreholes. The phenomenon of microseismicity triggering by borehole fluid injections is related to the process of the Frenkel-Biot slow wave propagation. In the low-frequency range (hours or days of fluid injection duration) this process reduces to the pore pressure diffusion. Fluid induced seismicity typically shows several diffusion indicating features, which are directly related to the rate of spatial grow, to the geometry of clouds of micro earthquake hypocentres and to their spatial density. Several fluid injection experiments were conducted at the German Continental Deep Drilling Site (KTB) in 1994, 2000 and 2003-2005. Microseismicity occurred at different depth intervals. We analyze this microseismicity in terms of its diffusion-related features. Its relation to the 3-D distribution of the seismic reflectivity has important rock physical and tectonic implications. Starting from such diffusion-typical signatures of man-made earthquakes, we seek analogous patterns for the earthquakes in Vogtland/Bohemia at the German/Czech border region in central Europe. There is strong geophysical evidence that there seismic events are correlated to fluid-related processes in the crust. We test the hypothesis that ascending magmatic fluids trigger earthquakes by the mechanism of pore pressure diffusion. This triggering process is mainly controlled by two physical fields, the hydraulic diffusivity and the seismic criticality (i.e., critical pore pressure value leading to failure; stable locations are characterized by higher critical pressures

  11. Geomechanical Engineering Concepts Applied to Deep Borehole Disposal Wells (United States)

    Herrick, C. G.; Haimson, B. C.; Lee, M.


    Deep borehole disposal (DBD) of certain defense-generated radioactive waste forms is being considered by the US Department of Energy (DOE) as an alternative to mined repositories. The 17 inch diameter vertical boreholes are planned to be drilled in crystalline basement rock. As part of an initial field test program, the DOE will drill a demonstration borehole, to be used to test equipment for handling and emplacing prototype nonradioactive waste containers, and a second smaller diameter borehole, to be used for site characterization. Both boreholes will be drilled to a depth of 5 km. Construction of such boreholes is expected to be complex because of their overall length, large diameter, and anticipated downhole conditions of high temperatures, pore pressures, and stress regimes. It is believed that successful development of DBD boreholes can only be accomplished if geologic and tectonic conditions are characterized and drill activities are designed based on that understanding. Our study focuses primarily on using the in situ state of stress to mitigate borehole wall failure, whether tensile or compressive. The measured stresses, or their constrained estimates, will include pore pressure, the vertical stress, the horizontal stresses and orientations, and thermally induced stresses. Pore pressure will be measured directly or indirectly. Horizontal stresses will be estimated from hydraulic fracturing tests, leak off tests, and breakout characteristics. Understanding the site stress condition along with the rock's strength characteristics will aid in the optimization of mud weight and casing design required to control borehole wall failure and other drilling problems.Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-6552A

  12. Evaluation of hydraulic properties in fractured rockmass

    Energy Technology Data Exchange (ETDEWEB)

    Lee, E. Y.; Jang, G. M. [Korea Nuclear Environment Technology Institute, Taejon (Korea, Republic of)


    Borehole packer test and fracture survey using borehole acoustic scanning method was performed in order to evaluate hydraulic characteristics of Tuff distributed in northern Yeosu area. Total of 303 fractures were detected and then orientation, aperture size of each fracture are analyzed. Only 12 % of detected fractures were identified as open fractures and others were filled with minerals such as calcite. This indicates that the hydraulic property of rockmass is influenced by fillings as well as aperture size. Mean of hydraulic conductivity of rockmass based on stochastic continuum theory was 5x 10{sup -9}m/s and it was coincident with harmonic mean. Anisotropy of hydraulic conductivity was analyzed by fracture network modeling interpretation. The result showed that horizontal and vertical components conductivity values were nearly same, therefore it might be concluded that the rockmass was hydraulically isotropic.

  13. Predicting Stress-induced Anisotropy around a Borehole (United States)

    Fang, X.; Fehler, M.; Zhu, Z.; Toksoz, M. N.; Earth Resources Laboratory


    The knowledge of the in situ stress state around a borehole is of primary importance for investigating the stability of the borehole, when estimating the likely orientations of open fractures, and for designing hydraulic fracture operations. Two major steps may be used to estimate the in situ stress: first, we measure the near-wellbore anisotropy from acoustic logs, which can be done using a relatively well-developed technique; second, we use some inversion scheme to estimate the in situ stress state by assuming that all near-wellbore anisotropy is caused by the anisotropic near-wellbore stress field that has been altered by the presence of the borehole. In order to develop an accurate and efficient inversion scheme, the relation between the stress and formation anisotropy needs to be quantitatively determined. Because the stress field near the wellbore is strongly influenced by the presence of the borehole, in this paper, we propose an iterative numerical approach to estimate the stress-induced anisotropy around a borehole for any given stress state by applying Mavko’s model (1995) and a finite-element method. The accuracy of our approach is validated through laboratory measurements of the stress-strain relation of Berea sandstone under uniaxial loading. Our numerical studies show that this approach can be applied to calculate the formation anisotropy around a borehole for a wide stress range. This approach could potentially provide a good forward model for the in situ stress inversion.

  14. Continuous monitoring of volcanoes with borehole strainmeters (United States)

    Linde, Alan T.; Sacks, Selwyn

    Monitoring of volcanoes using various physical techniques has the potential to provide important information about the shape, size and location of the underlying magma bodies. Volcanoes erupt when the pressure in a magma chamber some kilometers below the surface overcomes the strength of the intervening rock, resulting in detectable deformations of the surrounding crust. Seismic activity may accompany and precede eruptions and, from the patterns of earthquake locations, inferences may be made about the location of magma and its movement. Ground deformation near volcanoes provides more direct evidence on these, but continuous monitoring of such deformation is necessary for all the important aspects of an eruption to be recorded. Sacks-Evertson borehole strainmeters have recorded strain changes associated with eruptions of Hekla, Iceland and Izu-Oshima, Japan. Those data have made possible well-constrained models of the geometry of the magma reservoirs and of the changes in their geometry during the eruption. The Hekla eruption produced clear changes in strain at the nearest instrument (15 km from the volcano) starting about 30 minutes before the surface breakout. The borehole instrument on Oshima showed an unequivocal increase in the amplitude of the solid earth tides beginning some years before the eruption. Deformational changes, detected by a borehole strainmeter and a very long baseline tiltmeter, and corresponding to the remote triggered seismicity at Long Valley, California in the several days immediately following the Landers earthquake are indicative of pressure changes in the magma body under Long Valley, raising the question of whether such transients are of more general importance in the eruption process. We extrapolate the experience with borehole strainmeters to estimate what could be learned from an installation of a small network of such instruments on Mauna Loa. Since the process of conduit formation from the magma sources in Mauna Loa and other

  15. Deformation Monitoring by Borehole Geodetic Strainmeter in Turkey (United States)

    Ozener, Haluk; Aktug, Bahadir; Karabulut, Hayrullah; Ergintav, Semih; Dogru, Asli; Yilmaz, Onur; Mencin, David; Mattioli, Glen; Johnson, Wade; Gottlieb, Mike; Van Boskirik, Liz


    This project is aimed to study three-dimensional strain field resulting from deformation through North Anatolian Fault System (NAFS) in Marmara Region, Turkey. Within this project, two borehole observatories consisting of borehole strainmeters, borehole seismometers, tiltmeters, and pore pressure sensors have been deployed in Istanbul. These installations have been supported by Istanbul Development Agency (ISTKA) (financially) and UNAVCO (technically). Istanbul, located near the most active parts of the North Anatolian Fault, has been monitored by different observing techniques such as seismic networks and continuous/survey-mode GPS networks for decades. Borehole strainmeters are very sensitive to deformation in the range of less than a month and can capture signals with superior precision at local spatial scales. In this project, it will be possible to determine the movements precisely which can not be monitored with available measurement systems in the middle and the eastern part of Marmara Sea through NAFS. Our long term objective is to build a borehole monitoring system in the region. By integrating various data obtained from borehole observatories, we expect to get a better understanding of dynamics in the western NAF. In this presentation, we introduce data and ongoing analysis obtained with strainmeters.

  16. Borehole sampling of fracture populations - compensating for borehole sampling bias in crystalline bedrock aquifers, Mirror Lake, Grafton County, New Hampshire (United States)

    McDonald, G.D.; Paillet, Frederick L.; Barton, C.C.; Johnson, C.D.


    The clustering of orientations of hydraulically conductive fractures in bedrock at the Mirror Lake, New Hampshire fractured rock study site was investigated by comparing the orientations of fracture populations in two subvertical borehole arrays with those mapped on four adjacent subvertical roadcuts. In the boreholes and the roadcuts, the orientation of fracture populations appears very similar after borehole data are compensated for undersampling of steeply dipping fractures. Compensated borehole and pavement fracture data indicate a northeast-striking population of fractures with varying dips concentrated near that of the local foliation in the adjacent rock. The data show no correlation between fracture density (fractures/linear meter) and distance from lithologic contacts in both the boreholes and the roadcuts. The population of water-producing borehole fractures is too small (28 out of 610 fractures) to yield meaningful orientation comparisons. However, the orientation of large aperture fractures (which contains all the producing fractures) contains two or three subsidiary clusters in orientation frequency that are not evident in stereographic projections of the entire population containing all aperture sizes. Further, these subsidiary orientation clusters do not coincide with the dominant (subhorizontal and subvertical) regional fracture orientations.

  17. Sensitivity and type curves of cross-borehole flowmeter tests: application to heterogeneous fractured media. (United States)

    Ruelleu, S.; Bour, O.; Le Borgne, T.


    Crystalline rocks aquifers are very difficult to characterize since flow is mainly localized in few fractures or faults. In most cases, the large-scale hydraulic properties of such media strongly depend on the connectivity of few permeable fractures. To image and quantify the properties of such features, borehole flowmetry can be a very useful and efficient method that is also suitable when boreholes are screened. The methodology is based on the measurements of vertical flow both for single and cross-borehole configurations. In this study, we investigate through a numerical model the sensitivity of cross-borehole flowmeter tests to the geometry and properties of main permeable pathways. To model transient flow in heterogeneous media, we used a finite element method code where we reproduce few fractures and two boreholes. In each fracture, the diffusivity equation is solved. We considered different geometrical cases : a single fracture connecting two boreholes, two parallel fractures, and two intersecting fractures with a variable angle between the fractures. In the pumping well and in the observation borehole, we implemented borehole storage. For each geometry, we varied the hydraulic parameters and established cross-borehole flowmeters type curve as the typical variation of flow measured in an observation well in response to a pumping in an adjacent well. In most cases, our results appear very sensitive to the modelling of wellbore storage that affects the data especially in the early times, and for low fracture storativity. Nevertheless we do observe different shapes of type-curves depending on the geometrical connexion between fractures and boreholes. We also defined a new methodology more appropriate to identify the fracture connexions. However, our results show also that in some cases, one cannot distinguish the different type curves. Thus, uniqueness of the flow response is questioned. These results are compared with field examples obtained on the Ploemeur

  18. Lithologic and physicochemical properties and hydraulics of flow in and near the freshwater/saline-water transition zone, San Antonio segment of the Edwards aquifer, south-central Texas, based on water-level and borehole geophysical log data, 1999-2007 (United States)

    Lambert, Rebecca B.; Hunt, Andrew G.; Stanton, Gregory P.; Nyman, Michael B.


    The freshwater zone of the San Antonio segment of the Edwards aquifer in south-central Texas (hereinafter, the Edwards aquifer) is bounded to the south and southeast by a zone of transition from freshwater to saline water (hereinafter, the transition zone). The boundary between the two zones is the freshwater/saline-water interface (hereinafter, the interface), defined as the 1,000-milligrams per liter dissolved solids concentration threshold. This report presents the findings of a study, done by the U.S. Geological Survey in cooperation with the San Antonio Water System, to obtain lithologic properties (rock properties associated with known stratigraphic units) and physicochemical properties (fluid conductivity and temperature) and to analyze the hydraulics of flow in and near the transition zone of the Edwards aquifer on the basis of water-level and borehole geophysical log data collected from 15 monitoring wells in four transects during 1999-2007. No identifiable relation between conductivity values from geophysical logs in monitoring wells in all transects and equivalent freshwater heads in the wells at the times the logs were run is evident; and no identifiable relation between conductivity values and vertical flow in the boreholes concurrent with the times the logs were run is evident. The direction of the lateral equivalent freshwater head gradient and thus the potential lateral flow at the interface in the vicinity of the East Uvalde transect fluctuates between into and out of the freshwater zone, depending on recharge and withdrawals. Whether the prevailing direction on average is into or out of the freshwater zone is not clearly indicated. Equivalent freshwater head data do not indicate a prevailing direction of the lateral gradient at the interface in the vicinity of the Tri-County transect. The prevailing direction on average of the lateral gradient and thus potential lateral flow at the interface in the vicinity of the Kyle transect likely is from the

  19. Active monitoring of hydraulic and mechanical properties variations during the hydraulic stimulation of a fractured porous reservoir: Some preliminary results from the HPPP Project (United States)

    Cappa, F.; Guglielmi, Y.


    A new protocol of active geophysical monitoring is used to investigate the downhole changes in the hydromechanical response of a naturally porous reservoir layer with 80° dipping fractures where permeability was artificially enhanced by a hydraulic jacking test conducted by a step-wise increase of the fluid pressure. The protocol, called the High-Pulse Poroelasticity Protocol (HPPP) (, is focusing on controlled-impulsive source repeated observations and interpretation of rock properties changes over the seismic band of frequencies. The excitation source corresponds to a fast hydraulic pulse imposed in a small section of a borehole. The source is monitored with a special borehole probe based on fiber-optic sensors which allow dynamic fluid pressure/3D-mechanical deformation measurements, with reflection of light at specific wavelength from Fabry-Pérot or fiber Bragg gratings mounted between inflatable packers. Within the injection zone, fluid pressure and deformation waves of 1 to 500 Hz and static hydraulic diffusion are simultaneously measured to quantify the hydromechanical couplings Two identical pressure pulses were performed to test the rock three-dimensionnal mechanical response before and after the jacking test. It clearly appears that (1) the magnitude of the rock deformation is a factor of 3 higher, and (2) the principal deformation component pitch is rotated of about 20° with more radial deformation of the layer after the jacking test. Those preliminary tests show that the HPPP protocol can actively improve downhole monitoring of both hydraulic and mechanical bulk properties changes of rocks under strong dynamic stress-flow couplings.

  20. Reliability of Source Mechanisms for a Hydraulic Fracturing Dataset (United States)

    Eyre, T.; Van der Baan, M.


    Non-double-couple components have been inferred for induced seismicity due to fluid injection, yet these components are often poorly constrained due to the acquisition geometry. Likewise non-double-couple components in microseismic recordings are not uncommon. Microseismic source mechanisms provide an insight into the fracturing behaviour of a hydraulically stimulated reservoir. However, source inversion in a hydraulic fracturing environment is complicated by the likelihood of volumetric contributions to the source due to the presence of high pressure fluids, which greatly increases the possible solution space and therefore the non-uniqueness of the solutions. Microseismic data is usually recorded on either 2D surface or borehole arrays of sensors. In many cases, surface arrays appear to constrain source mechanisms with high shear components, whereas borehole arrays tend to constrain more variable mechanisms including those with high tensile components. The abilities of each geometry to constrain the true source mechanisms are therefore called into question.The ability to distinguish between shear and tensile source mechanisms with different acquisition geometries is investigated using synthetic data. For both inversions, both P- and S- wave amplitudes recorded on three component sensors need to be included to obtain reliable solutions. Surface arrays appear to give more reliable solutions due to a greater sampling of the focal sphere, but in reality tend to record signals with a low signal to noise ratio. Borehole arrays can produce acceptable results, however the reliability is much more affected by relative source-receiver locations and source orientation, with biases produced in many of the solutions. Therefore more care must be taken when interpreting results.These findings are taken into account when interpreting a microseismic dataset of 470 events recorded by two vertical borehole arrays monitoring a horizontal treatment well. Source locations and

  1. Accurate borehole probe calibration

    Energy Technology Data Exchange (ETDEWEB)

    Tchen, T.; Eisler, P. (CSIRO, Mount Waverley, Vic. (Australia). Division of Geomechanics)

    The In Situ Minerals Analysis Group in the CSIRO Division of Geomechanics has developed quantitative borehole logging techniques applicable to iron-ore and coal deposits. They are used currently to determine the formation density, either the iron-ore grades or the raw coal-ash contents, as appropriate, and the borehole diameter. The in-situ analyses depend on probe-calibration equations which were formulated by linear regression analysis that related the probe's spectral outputs with the required geological variable. Calibration equations consisting of a linear combination of first-order terms gave excellent assaying accuracy. The group achieved further improvements in assaying accuracy by developing a more generalised calibration model based on second-order terms and cross-product terms of the probe's spectral parameters. The logging data used for the statistical analysis were recorded in mine development boreholes at three Pilbara iron-ore mines and at a Queensland coal mine. Application of the generalised model, in place of the first-order model, resulted in a reduction of the root mean square (RMS) deviation between assays obtained in the laboratory and by logging, of about 15% relative for iron-ore grades and of about 8% relative for raw coal-ash content. The study also shows that the accuracy obtained using the conventional, non-spectrometric calibration model is inferior to that obtained by using either of the two spectrometric models, where the comparisons made are based on the same set of logging data. 8 refs., 6 figs., 3 tabs.

  2. Numerical Borehole Breakdown Investigations using XFEM (United States)

    Beckhuis, Sven; Leonhart, Dirk; Meschke, Günther


    During pressurization of a wellbore a typical downhole pressure record shows the following regimes: first the applied wellbore pressure balances the reservoir pressure, then after the compressive circumferential hole stresses are overcome, tensile stresses are induced on the inside surface of the hole. When the magnitude of these stresses reach the tensile failure stress of the surrounding rock medium, a fracture is initiated and propagates into the reservoir. [1] In standard theories this pressure, the so called breakdown pressure, is the peak pressure in the down-hole pressure record. However experimental investigations [2] show that the breakdown did not occur even if a fracture was initiated at the borehole wall. Drilling muds had the tendency to seal and stabilize fractures and prevent fracture propagation. Also fracture mechanics analysis of breakdown process in mini-frac or leak off tests [3] show that the breakdown pressure could be either equal or larger than the fracture initiation pressure. In order to gain a deeper understanding of the breakdown process in reservoir rock, numerical investigations using the extended finite element method (XFEM) for hydraulic fracturing of porous materials [4] are discussed. The reservoir rock is assumed to be pre-fractured. During pressurization of the borehole, the injection pressure, the pressure distribution and the position of the highest flux along the fracture for different fracturing fluid viscosities are recorded and the influence of the aforementioned values on the stability of fracture propagation is discussed. [1] YEW, C. H. (1997), "Mechanics of Hydraulic Fracturing", Gulf Publishing Company [2] MORITA, N.; BLACK, A. D.; FUH, G.-F. (1996), "Borehole Breakdown Pressure with Drilling Fluids". International Journal of Rock Mechanics and Mining Sciences 33, pp. 39-51 [3] DETOURNAY, E.; CARBONELL, R. (1996), "Fracture Mechanics Analysis of the Breakdown Process in Minifrac or Leakoff Test", Society of Petroleum

  3. Hydraulic properties from pumping tests data of aquifers in Azare ...

    African Journals Online (AJOL)

    Hydraulic properties from pumping tests data of aquifers in Azare area, North Eastern Nigeria. AC Tse, PA Amadi. Abstract. Pumping test data from twelve boreholes in Azare area were analysed to determine the hydraulic properties of the aquifers, and the availability of water to meet the conjugate demands of the increasing ...

  4. Structural analysis of the Valence basin (SE France) based on kriging and borehole data: implications for hercynian fault zone behaviour in geothermic reservoirs. (United States)

    Chabani, Arezki; Mehl, Caroline; Bruel, Dominique; Cojan, Isabelle


    The Valence basin is a 130 km-long and 60 km-wide Tertiary sub-basin situated north to the SE basin of France, in the central part of the European Cenozoic RIft System (ECRIS). That structural key position in a naturally fractured hostrock associated with a favorable thermal regime make that basin a good target for geothermal exploitation in France. The structure and kinematics of the Valence basin is controlled by a several kilometer-scale hercynian fault system that may have a strong influence on fluid flows and thermal anomalies within the basin. This study aimed to constrain the geometry of deposits and the way they fracture regards to the major faults, to determine their diagenetic evolution and to characterize the hydraulic behavior of the major faults. We thus performed a structural model of the basin and analyzed the Montoison borehole. Kriging on data pointed on 348 boreholes from BSS, synthetic boreholes calculated from two seismic lines and isohypses from existing models allowed modeling the geometry of basement and the ceno-mesozoic unconformity. Basement is structured by two pluri-kilometer long fault corridors striking N/S to NE/SW. The central extends laterally on around 1 kilometer and has been identified as a segment of the Cevennes fault. The maximum depth of the basement is around 6000 m and is situated between the two corridors. Interpretations on seismic lines highlight a westward migration of Cenozoic depocenters within time. A structural analysis of the Montoison borehole confirms it is affected by a major fault interpreted as the Cevennes fault. Fault zone cuts across the Keuper and is characterized by an heterometric breccia within marly layers. The entire sedimentary pile recorded 2 sets of fractures: perpendicular and parallel to the borehole axis. Both sets are recrystallized. Nature of recrystallization (quartz, calcite and dolomite) strongly depends on the hostrock. An important thread of barite is located under the fault zone, putting

  5. Deep Borehole Field Test Laboratory and Borehole Testing Strategy

    Energy Technology Data Exchange (ETDEWEB)

    Kuhlman, Kristopher L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Brady, Patrick V. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); MacKinnon, Robert J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Heath, Jason E. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Herrick, Courtney G. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jensen, Richard P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Gardner, W. Payton [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Sevougian, S. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bryan, Charles R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Jang, Je-Hun [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Stein, Emily R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Bauer, Stephen J. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Daley, Tom [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Freifeld, Barry M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Birkholzer, Jens [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Spane, Frank A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    Deep Borehole Disposal (DBD) of high-level radioactive wastes has been considered an option for geological isolation for many years (Hess et al. 1957). Recent advances in drilling technology have decreased costs and increased reliability for large-diameter (i.e., ≥50 cm [19.7”]) boreholes to depths of several kilometers (Beswick 2008; Beswick et al. 2014). These advances have therefore also increased the feasibility of the DBD concept (Brady et al. 2009; Cornwall 2015), and the current field test design will demonstrate the DBD concept and these advances. The US Department of Energy (DOE) Strategy for the Management and Disposal of Used Nuclear Fuel and High-Level Radioactive Waste (DOE 2013) specifically recommended developing a research and development plan for DBD. DOE sought input or expression of interest from States, local communities, individuals, private groups, academia, or any other stakeholders willing to host a Deep Borehole Field Test (DBFT). The DBFT includes drilling two boreholes nominally 200m [656’] apart to approximately 5 km [16,400’] total depth, in a region where crystalline basement is expected to begin at less than 2 km depth [6,560’]. The characterization borehole (CB) is the smaller-diameter borehole (i.e., 21.6 cm [8.5”] diameter at total depth), and will be drilled first. The geologic, hydrogeologic, geochemical, geomechanical and thermal testing will take place in the CB. The field test borehole (FTB) is the larger-diameter borehole (i.e., 43.2 cm [17”] diameter at total depth). Surface handling and borehole emplacement of test package will be demonstrated using the FTB to evaluate engineering feasibility and safety of disposal operations (SNL 2016).

  6. The Geothermic Fatigue Hydraulic Fracturing Experiment in Äspö Hard Rock Laboratory, Sweden: New Insights Into Fracture Process through In-situ AE Monitoring (United States)

    Kwiatek, G.; Plenkers, K.; Zang, A.; Stephansson, O.; Stenberg, L.


    The geothermic Fatigue Hydraulic Fracturing (FHF) in situ experiment (Nova project 54-14-1) took place in the Äspö Hard Rock Laboratory/Sweden in a 1.8 Ma old granitic to dioritic rock mass. The experiment aims at optimizing geothermal heat exchange in crystalline rock mass by multistage hydraulic fracturing at 10 m scale. Six fractures are driven by three different water injection schemes (continuous, cyclic, pulse pressurization) inside a 28 m long, horizontal borehole at depth level 410 m. The rock volume subject to hydraulic fracturing and monitored by three different networks with acoustic emission (AE), micro-seismicity and electromagnetic sensors is about 30 m x 30 m x 30 m in size. The 16-channel In-situ AE monitoring network by GMuG monitored the rupture generation and propagation in the frequency range 1000 Hz to 100,000 Hz corresponding to rupture dimensions from cm- to dm-scale. The in-situ AE monitoring system detected and analyzed AE activity in-situ (P- and S-wave picking, localization). The results were used to review the ongoing microfracturing activity in near real-time. The in-situ AE monitoring network successfully recorded and localized 196 seismic events for most, but not all, hydraulic fractures. All AE events detected in-situ occurred during fracturing time periods. The source parameters (fracture sizes, moment magnitudes, static stress drop) of AE events framing injection periods were calculated using the combined spectral fitting/spectra ratio techniques. The AE activity is clustered in space and clearly outline the fractures location, its orientation, and expansion as well as their temporal evolution. The outward migration of AE events away from the borehole is observed. Fractures extend up to 7 m from the injection interval in the horizontal borehole. The fractures orientation and location correlate for most fractures roughly with the results gained by image packer. Clear differences in seismic response between hydraulic fractures in

  7. Influence of pressure change during hydraulic tests on fracture aperture. (United States)

    Ji, Sung-Hoon; Koh, Yong-Kwon; Kuhlman, Kristopher L; Lee, Moo Yul; Choi, Jong Won


    In a series of field experiments, we evaluate the influence of a small water pressure change on fracture aperture during a hydraulic test. An experimental borehole is instrumented at the Korea Atomic Energy Research Institute (KAERI) Underground Research Tunnel (KURT). The target fracture for testing was found from the analyses of borehole logging and hydraulic tests. A double packer system was developed and installed in the test borehole to directly observe the aperture change due to water pressure change. Using this packer system, both aperture and flow rate are directly observed under various water pressures. Results indicate a slight change in fracture hydraulic head leads to an observable change in aperture. This suggests that aperture change should be considered when analyzing hydraulic test data from a sparsely fractured rock aquifer. © 2012, The Author(s). Groundwater © 2012, National Ground Water Association.

  8. The seismogenic Gole Larghe Fault Zone (Italian Southern Alps): quantitative 3D characterization of the fault/fracture network, mapping of evidences of fluid-rock interaction, and modelling of the hydraulic structure through the seismic cycle (United States)

    Bistacchi, A.; Mittempergher, S.; Di Toro, G.; Smith, S. A. F.; Garofalo, P. S.


    The Gole Larghe Fault Zone (GLFZ) was exhumed from 8 km depth, where it was characterized by seismic activity (pseudotachylytes) and hydrous fluid flow (alteration halos and precipitation of hydrothermal minerals in veins and cataclasites). Thanks to glacier-polished outcrops exposing the 400 m-thick fault zone over a continuous area > 1.5 km2, the fault zone architecture has been quantitatively described with an unprecedented detail, providing a rich dataset to generate 3D Discrete Fracture Network (DFN) models and simulate the fault zone hydraulic properties. The fault and fracture network has been characterized combining > 2 km of scanlines and semi-automatic mapping of faults and fractures on several photogrammetric 3D Digital Outcrop Models (3D DOMs). This allowed obtaining robust probability density functions for parameters of fault and fracture sets: orientation, fracture intensity and density, spacing, persistency, length, thickness/aperture, termination. The spatial distribution of fractures (random, clustered, anticlustered…) has been characterized with geostatistics. Evidences of fluid/rock interaction (alteration halos, hydrothermal veins, etc.) have been mapped on the same outcrops, revealing sectors of the fault zone strongly impacted, vs. completely unaffected, by fluid/rock interaction, separated by convolute infiltration fronts. Field and microstructural evidence revealed that higher permeability was obtained in the syn- to early post-seismic period, when fractures were (re)opened by off-fault deformation. We have developed a parametric hydraulic model of the GLFZ and calibrated it, varying the fraction of faults/fractures that were open in the post-seismic, with the goal of obtaining realistic fluid flow and permeability values, and a flow pattern consistent with the observed alteration/mineralization pattern. The fraction of open fractures is very close to the percolation threshold of the DFN, and the permeability tensor is strongly anisotropic

  9. Drilling a borehole for LEP

    CERN Multimedia


    Boreholes were drilled along the earlier proposed line of the LEP tunnel under the Jura to find out the conditions likely to be encountered during the construction of the LEP tunnel (Annual Report 1981 p. 106, Fig. 10).

  10. Safety valve for offshore borehole

    Energy Technology Data Exchange (ETDEWEB)

    McGill, H.L.; Randermann, E. Jr.; Musik, O.J.


    The invention concerns a new and improved submarine safety valve with a valve element which rotate, which can be used, in emergencies, to separate the wound-up piping which extends into the borehole and to close the production line.

  11. Regional Seismic Arrays and Nuclear Test Ban Verification (United States)


    Leary, Y.-G. Li, and D. V. Manov .. 717 Borehole Seismometer, A Fiber Optical, by P. C. Leary, D. V. Manov , and Y. G. Li ........... 218 Bostock, M. G...1297 Leary, P. C., D. V. Manov , and Y. G. Li-A Fiber Optical Borehole Seismometer ............ 218 Leary, P. C. and...Y.-G. Li-Fault Zone Trapped Seismic Waves ............................ 1245 Leary, P. C. Y.-G. Li, and D. V. Manov -A Microprocessor-Based Borehole

  12. Sealing of investigation boreholes, Phase 4 - Final report

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Luleaa Technical University, Luleaa (Sweden); Ramqvist, Gunnar [El-Tekno AB, Figeholm (Sweden); Bockgaard, Niclas [Golder Associates, Goeteborg (Sweden); Ekman, Lennart [LE Geokonsult AB, Baelinge (Sweden)


    The report describes the outcome of Phase 4 of the project 'Sealing of investigation boreholes', which deals with 1) characterization and planning of borehole sealing, 2) performance and quality assessment, 3) sealing of large diameter holes, and 4) interaction of clay and concrete plugs. A specific goal was to find ways to characterize, plan and seal of boreholes so that their impact on the overall hydraulic performance of the repository rock can predicted and controlled. The work comprised selection of representative 'reference holes' at the Laxemar and Forsmark sites for development of a general programme for planning and simulating implementation of borehole plugging campaigns, considering also cost issues. A second aim was to define and quantify the role of seals in the reference holes for finding out how important sealing really is. A third was to test a practical way to seal large diameter boreholes and a fourth to find out how concrete matures and performs in contact with smectite clay. The study demonstrated, in conclusion, the need for developing techniques for preparing deep boreholes before lasting seals are installed in them, since poor sealing can short-circuit hydraulically important fracture zones intersected by the holes. The practically oriented sealing activities showed that the technique developed for tight sealing of large-diameter boreholes is practical and feasible. The issue of chemical stability was investigated by testing the performance and constitution of a plug consisting of CBI concrete in contact with smectite-rich seals for almost three years. This study showed that none of them underwent substantial degradation in this period of time, but chemical reactions and thereby generated changes in physical behaviour of the plug components had taken place, particularly in the clay. The rate of degradation is, however, not yet known. It was concluded from this study that it is suitable to carry out a corresponding

  13. A new modified borehole jack for stiff rock (United States)

    Azzam, R.; Bock, H.


    The modified borehole jacking method, as introduced by De La Cruz in 1978, has important theoretical advantages over the common method which is associated with the name Goodman. So far, however, the modified method has not succeeded, mainly due to a lack of suitable instrumentation. To overcome this problem, a new type of modified borehole jack has been designed, built and tested. The new jack incorporates two highly innovative components: a recoverable sensor for measuring tangential strain at borehole surfaces and stacked hydraulic cylinders for extra-high load outputs. The new jack has been developed to the point at which its technical feasibility under field conditions, including its capability of yielding meaningful results, is demonstrated. Calibration in a hollow steel cylinder revealed that the new modified jack yields the correct Young's modulus within an error margin of less than ±5%. In-situ jacking tests were carried out at a major dam construction site. Results were obtained from both common and modified borehole jacking and from conventional laboratory testing of drill cores. The results of these tests are presented and discussed against the background of the particular rock conditions at the site.

  14. Imaging hydraulic fractures by microseismic migration for downhole monitoring system (United States)

    Lin, Ye; Zhang, Haijiang


    It has been a challenge to accurately characterize fracture zones created by hydraulic fracturing from microseismic event locations. This is because generally detected events are not complete due to the associated low signal to noise ratio and some fracturing stages may not produce microseismic events even if fractures are well developed. As a result, spatial distribution of microseismic events may not well represent fractured zones by hydraulic fracturing. Here, we propose a new way to characterize the fractured zones by reverse time migration (RTM) of microseismic waveforms from some events. This is based on the fact that fractures filled with proppants and other fluids can act as strong scatterers for seismic waves. Therefore, for multi-stage hydraulic fracturing, recorded waveforms from microseismic events induced in a more recent stage may be scattered by fractured zones from previous stages. Through RTM of microseismic waveforms in the current stage, we can determine fractured zones created in previous stages by imaging area of strong scattering. We test the feasibility of this method using synthetic models with different configurations of microseismic event locations and borehole sensor positions for a 2D downhole microseismic monitoring system. Synthetic tests show that with a few events fractured zones can be directly imaged and thus the stimulated reservoir volume (SRV) can be estimated. Compared to the conventional location-based SRV estimation method, the proposed new method does not depend on the completeness of detected events and only a limited number of detected and located events are necessary for characterizing fracture distribution. For simplicity, the 2D model is used for illustrating the concept of microseismic RTM for imaging the fracture zone but the method can be adapted to real cases in the future.

  15. Borehole geophysical investigation of a formerly used defense site, Machiasport, Maine, 2003-2006 (United States)

    Johnson, Carole D.; Mondazzi, Remo A.; Joesten, Peter K.


    The U.S. Geological Survey, in cooperation with the U.S. Army Corps of Engineers, collected borehole geophysical logs in 18 boreholes and interpreted the data along with logs from 19 additional boreholes as part of an ongoing, collaborative investigation at three environmental restoration sites in Machiasport, Maine. These sites, located on hilltops overlooking the seacoast, formerly were used for military defense. At each of the sites, chlorinated solvents, used as part of defense-site operations, have contaminated the fractured-rock aquifer. Borehole geophysical techniques and hydraulic methods were used to characterize bedrock lithology, fractures, and hydraulic properties. In addition, each geophysical method was evaluated for effectiveness for site characterization and for potential application for further aquifer characterization and (or) evaluation of remediation efforts. Results of borehole geophysical logging indicate the subsurface is highly fractured, metavolcanic, intrusive, metasedimentary bedrock. Selected geophysical logs were cross-plotted to assess correlations between rock properties. These plots included combinations of gamma, acoustic reflectivity, electromagnetic induction conductivity, normal resistivity, and single-point resistance. The combined use of acoustic televiewer (ATV) imaging and natural gamma logs proved to be effective for delineating rock types. Each of the rock units in the study area could be mapped in the boreholes, on the basis of the gamma and ATV reflectivity signatures. The gamma and mean ATV reflectivity data were used along with the other geophysical logs for an integrated interpretation, yielding a determination of quartz monzonite, rhyolite, metasedimentary units, or diabase/gabbro rock types. The interpretation of rock types on the basis of the geophysical logs compared well to drilling logs and geologic mapping. These results may be helpful for refining the geologic framework at depth. A stereoplot of all fractures

  16. Comparative study of methods to estimate hydraulic parameters in the hydraulically undisturbed Opalinus Clay (Switzerland)

    Energy Technology Data Exchange (ETDEWEB)

    Yu, C.; Matray, J.-M. [Institut de Radioprotection et de Sûreté Nucléaire, Fontenay-aux-Roses, (France); Yu, C.; Gonçalvès, J. [Aix Marseille Université UMR 6635 CEREGE Technopôle Environnement Arbois-Méditerranée Aix-en-Provence, Cedex 4 (France); and others


    The deep borehole (DB) experiment gave the opportunity to acquire hydraulic parameters in a hydraulically undisturbed zone of the Opalinus Clay at the Mont Terri rock laboratory (Switzerland). Three methods were used to estimate hydraulic conductivity and specific storage values of the Opalinus Clay formation and its bounding formations through the 248 m deep borehole BDB-1: application of a Poiseuille-type law involving petrophysical measurements, spectral analysis of pressure time series and in situ hydraulic tests. The hydraulic conductivity range in the Opalinus Clay given by the first method is 2 × 10{sup -14}-6 × 10{sup -13} m s{sup -1} for a cementation factor ranging between 2 and 3. These results show low vertical variability whereas in situ hydraulic tests suggest higher values up to 7 × 10{sup -12} m s{sup -1}. Core analysis provides economical estimates of the homogeneous matrix hydraulic properties but do not account for heterogeneities at larger scale such as potential tectonic conductive features. Specific storage values obtained by spectral analysis are consistent and in the order of 10{sup -6} m{sup -1}, while formulations using phase shift and gain between pore pressure signals were found to be inappropriate to evaluate hydraulic conductivity in the Opalinus Clay. The values obtained are globally in good agreement with the ones obtained previously at the rock laboratory. (authors)

  17. Hydraulic structures

    CERN Document Server

    Chen, Sheng-Hong


    This book discusses in detail the planning, design, construction and management of hydraulic structures, covering dams, spillways, tunnels, cut slopes, sluices, water intake and measuring works, ship locks and lifts, as well as fish ways. Particular attention is paid to considerations concerning the environment, hydrology, geology and materials etc. in the planning and design of hydraulic projects. It also considers the type selection, profile configuration, stress/stability calibration and engineering countermeasures, flood releasing arrangements and scouring protection, operation and maintenance etc. for a variety of specific hydraulic structures. The book is primarily intended for engineers, undergraduate and graduate students in the field of civil and hydraulic engineering who are faced with the challenges of extending our understanding of hydraulic structures ranging from traditional to groundbreaking, as well as designing, constructing and managing safe, durable hydraulic structures that are economical ...

  18. Surface and Subsurface Geodesy Combined with Active Borehole Experimentation for the Advanced Characterization of EGS Reservoirs

    Energy Technology Data Exchange (ETDEWEB)

    Elsworth, Derek [Pennsylvania State Univ., University Park, PA (United States); Im, Kyungjae [Pennsylvania State Univ., University Park, PA (United States); Guglielmi, Yves [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Mattioli, Glen [Univ. of Texas, Arlington, TX (United States). UNAVCO


    We explore the utility of combining active downhole experimentation with borehole and surface geodesy to determine both the characteristics and evolving state of EGS reservoirs during stimulation through production. The study is divided into two parts. We demonstrate the feasibility of determining in situ reservoir characteristics of reservoir size, strain and fracture permeability and their dependence on feedbacks of stress and temperature using surface and borehole geodetic measurements (Part I). We then define the opportunity to apply the unique hydraulic pulse protocol (HPP) borehole tool to evaluate reservoir state. This can be accomplished by monitoring and co-inverting measured reservoir characteristics (from the HPP tool) with surface geodetic measurements of deformation, tilt and strain with continuous measurements of borehole-wall strain (via optical fiber and fiber Bragg gratings) and measured flow rates (Part II).

  19. Preliminary results from hot-water drilling and borehole instrumentation on Store Glacier, West Greenland (United States)

    Doyle, S. H.; Christoffersen, P.; Hubbard, B. P.; Young, T. J.; Hofstede, C. M.; Box, J.; Todd, J.; Bougamont, M. H.; Hubbard, A.


    As part of the Subglacial Access and Fast Ice Research Experiment (SAFIRE) pressurised hot water was used to drill four 603-616 m-long boreholes to the bed of the Greenland Ice Sheet at a site located 30 km from the calving front of fast-flowing, marine-terminating Store Glacier (70° N, ~1000 m elevation). Despite the boreholes freezing within hours, 4 wired sensor strings were successfully deployed in three of the boreholes. These included a thermistor string to obtain the englacial temperature profile installed in the same borehole as a string of tilt sensors to measure borehole deformation, and two sets of water pressure, electrical conductivity and turbidity sensors installed just above the bed in separate, adjacent boreholes. The boreholes made a strong hydrological connection to the bed during drilling, draining rapidly to ~80 m below the ice surface. The connection of subsequent boreholes was observed as a perturbation in water pressure and temperature recorded in neighbouring boreholes, indicating an effective hydrological sub- or en-glacial connection between them. The sensors, which were all connected to loggers at the surface by cables, operated for between ~30 and 80+ days before indications suggest that the cables stretched and then snapped - with the lowermost sensors failing first. The records obtained from these sensors reveal (i) high and increasing water pressure varying diurnally close to overburden albeit of a small magnitude (~ 0.3 m H2O), (ii) a minimum extrapolated englacial temperature of -21°C with above-freezing temperatures at the bed, and (iv) high rates of internal deformation and strain increasing towards the bed as evinced by increasing tilt with depth. These borehole observations are complemented by GPS measurements of ice motion, meteorological data, and seismic and radar surveys.

  20. Optimization of Deep Borehole Systems for HLW Disposal

    Energy Technology Data Exchange (ETDEWEB)

    Driscoll, Michael [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Baglietto, Emilio [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Buongiorno, Jacopo [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Lester, Richard [Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States); Brady, Patrick [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Arnold, B. W. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This is the final report on a project to update and improve the conceptual design of deep boreholes for high level nuclear waste disposal. The effort was concentrated on application to intact US legacy LWR fuel assemblies, but conducted in a way in which straightforward extension to other waste forms, host rock types and countries was preserved. The reference fuel design version consists of a vertical borehole drilled into granitic bedrock, with the uppermost kilometer serving as a caprock zone containing a diverse and redundant series of plugs. There follows a one to two kilometer waste canister emplacement zone having a hole diameter of approximately 40-50 cm. Individual holes are spaced 200-300 m apart to form a repository field. The choice of verticality and the use of a graphite based mud as filler between the waste canisters and the borehole wall liner was strongly influenced by the expectation that retrievability would continue to be emphasized in US and worldwide repository regulatory criteria. An advanced version was scoped out using zinc alloy cast in place to fill void space inside a disposal canister and its encapsulated fuel assembly. This excludes water and greatly improves both crush resistance and thermal conductivity. However the simpler option of using a sand fill was found adequate and is recommended for near-term use. Thermal-hydraulic modeling of the low permeability and porosity host rock and its small (≤ 1%) saline water content showed that vertical convection induced by the waste’s decay heat should not transport nuclides from the emplacement zone up to the biosphere atop the caprock. First order economic analysis indicated that borehole repositories should be cost-competitive with shallower mined repositories. It is concluded that proceeding with plans to drill a demonstration borehole to confirm expectations, and to carry out priority experiments, such as retention and replenishment of in-hole water is in order.

  1. The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics (United States)

    Schmitt, Douglas R.; Liberty, Lee M.; Kessler, James E.; Kuck, Jochem; Kofman, Randolph; Bishop, Ross; Shervais, John W.; Evans, James P.; Champion, Duane E.


    Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density logs employing active sources were deployed through the drill string, and although not fully calibrated for such a situation do provide semi-quantitative information related to the ‘stratigraphy’ of the basalt flows and on the existence of alteration minerals. Electrical resistivity logs highlight the existence of some fracture and mineralized zones. Magnetic susceptibility together with the vector magnetic field measurements display substantial variations that, in combination with laboratory measurements, may provide a tool for tracking magnetic field reversals along the borehole. Full waveform sonic logs highlight the variations in compressional and shear velocity along the borehole. These, together with the high resolution borehole seismic measurements display changes with depth that are not yet understood. The borehole seismic measurements indicate that seismic arrivals are obtained at depth in the formations and that strong seismic reflections are produced at lithological contacts seen in the corresponding core logging. Finally, oriented ultrasonic borehole televiewer images were obtained over most of the wells and these correlate well with the nearly 6 km of core obtained. This good image log to core correlations, particularly with regards to drilling induced breakouts and tensile borehole and core fractures will allow for confident estimates of stress directions and or placing constraints on stress magnitudes. Such correlations will be used to orient in core orientation giving information useful in hydrological assessments, paleomagnetic dating, and structural volcanology.

  2. Broadband waveforms and site effects at a borehole seismometer in the Po alluvial basin (Italy

    Directory of Open Access Journals (Sweden)

    L. Margheriti


    Full Text Available Broadband seismograms recorded at a borehole three-component (high dynamic range seismic station in the Po Valley (Northern Italy were analyzed to study the velocity structure of the shallow sedimentary layers as well as the local site effects in soft sediments. The broadband borehole seismometer was installed at a depth of 135 m just below the quaternary basement, while a second digital broadband seismometer was installed in the same site at the Earth surface. The velocity structure in the shallower layers was determined both by means of cross-hole and up-hole measurements and by inverting seismic data recorded during a seismic exploration experiment.Velocity discontinuities are quite well related to the stratigraphy of the site. We are interested to record local earthquakes as well as regional and teleseismic events. The analyzed data set includes local, regional and teleseismic events, most of which were recorded during the seismic sequence that started on October 15, 1996, near Reggio Emilia 80 km away from the borehole site. The orientation of the borehole sensor is determined using the recordings of a teleseismic event and of some local earthquakes. The noise reduction for the borehole sensor is 2 decades in power spectral density at frequencies larger than 1.0 Hz. We studied the site amplification of the shallow alluvial layers by applying the spectral ratio method. We analyzed the spectral ratios of noise recorded by the surface and borehole seismometers as well as those from local earthquakes. We compared these observations with a theoretical model for the site response computed by the Haskell-Thomson method.

  3. Modeling the Hydraulic Fracture Stimulation performed for Reservoir Permeability Enhancement at the Grimsel Test Site, Switzerland (United States)

    Vogler, D.; Settgast, R.; Gischig, V.; Jalali, M.; Doetsch, J.; Valley, B.; Evans, K. F.; Sherman, C.; Saar, M. O.; Amann, F.


    In-situ hydraulic stimulation has been performed on the decameter scale in the Deep Underground rock Laboratory (DUG Lab) at the Grimsel Test Site (GTS), Switzerland. The test site consists of granodiorite with a low fracture density and has been well characterized. The GTS is chosen as it represents physical properties representative for crystalline basement where the development of deep enhanced geothermal systems are planned for the future. Conducted stimulation was performed in a number of boreholes, with 3-4 packer intervals in each borehole subjected to repeated stimulation. During each stimulation event, fluid injection pressure, injection flow rate and microseismic events were recorded amongst others. Fully coupled 3D simulations have been performed with the LLNL's GEOS simulation framework. The methods applied in the simulation of the experiments address physical processes such as rock deformation/stress, LEFM fracture mechanics, fluid flow in the fracture and matrix, and the generation of micro-seismic events. This allows investigation in which we may estimate the distance of fracture penetration during the injection phase and correlate the simulated injection pressure with experimental data during injection, as well as post shut-in. Additionally, the extent of the fracture resulting from the numerical model are compared with the spatial distribution of the microseismic events recorded in the experiment.

  4. Application of time-lapse seismic shear wave inversion to characterize the stimulated rock volume in the Niobrara and Codell Reservoirs, Wattenberg Field, CO (United States)

    Mueller, Staci K.

    Advances in horizontal drilling and completions in shale reservoirs have allowed operators to extract hydrocarbons within low permeability reservoirs that were once impossible to access. The integration of time-lapse multicomponent seismic data with engineering technology aids in the characterization of these reservoirs through monitoring. This thesis investigates the fast and slow shear wave components of a time-lapse, nine-component seismic survey to determine the stimulated volume in the Niobrara and Codell reservoir intervals. The time-lapse post-stack inversions of the shear wave datasets provide insight into how the shear impedance is affected by hydraulic fracturing through the work of cross-equalized seismic shear impedances and shear wave splitting. The study area is the Wishbone Section within Wattenberg Field, CO, which is owned and operated by Anadarko Petroleum Corporation and contains eleven horizontal wells that vary in spacing and completion methods. Shear seismic data sets were acquired over this section before and after hydraulic stimulation. The time-lapse shear seismic inversions show an increase in fast shear wave velocity and a decrease in slow shear velocity after stimulation. The sensitivity of both the fast and slow shear seismic to stimulation correlates with the net pressure trends at each stage. Borehole image log interpretations are compared to the inversions to analyze the affect that a complex fracture network has on induced anisotropy. The stimulated volume for the Niobrara and Codell reservoir intervals are now more accurately defined. Time-lapse shear seismic is the only technology that is able to define the stimulated rock volume and reveal areas that are not being accessed by the wells currently drilled. These areas are now detected within the Wishbone section, and may be candidates for future re-completion.

  5. Site Characterization for a Deep Borehole Field Test (United States)

    Kuhlman, K. L.; Hardin, E. L.; Freeze, G. A.; Sassani, D.; Brady, P. V.


    The US Department of Energy Office of Nuclear Energy is at the beginning of 5-year Deep Borehole Field Test (DBFT) to investigate the feasibility of constructing and characterizing two boreholes in crystalline basement rock to a depth of 5 km (16,400 ft). The concept of deep borehole disposal for radioactive waste has some advantages over mined repositories, including incremental construction and loading, the enhanced natural barriers provided by deep continental crystalline basement, and reduced site characterization. Site characterization efforts need to determine an eligible site that does not have the following disqualifying characteristics: greater than 2 km to crystalline basement, upward vertical fluid potential gradients, presence of economically exploitable natural resources, presence of high permeability connection to the shallow subsurface, and significant probability of future seismic or volcanic activity. Site characterization activities for the DBFT will include geomechanical (i.e., rock in situ stress state, and fluid pressure), geological (i.e., rock and fracture infill lithology), hydrological (i.e., quantity of fluid, fluid convection properties, and solute transport mechanisms), and geochemical (i.e., rock-water interaction and natural tracers) aspects. Both direct (i.e., sampling and in situ testing) and indirect (i.e., borehole geophysical) methods are planned for efficient and effective characterization of these site aspects and physical processes. Borehole-based characterization will be used to determine the variability of system state (i.e., stress, pressure, temperature, and chemistry) with depth, and interpretation of material and system parameters relevant to numerical site simulation. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE

  6. Seismic Barrier Protection of Critical Infrastructure (United States)

    Haupt, R.; Liberman, V.; Rothschild, M.


    Each year, on average a major magnitude-8 earthquake strikes somewhere in the world. In addition, 10,000 earthquake related deaths occur annually, where collapsing buildings claim by far most lives. Moreover, in recent events, industry activity of oil extraction and wastewater reinjection are suspect to cause earthquake swarms that threaten high-value oil pipeline networks, U.S. oil storage reserves, and civilian homes. Earthquake engineering building structural designs and materials have evolved over many years to minimize the destructive effects of seismic surface waves. However, even under the best engineering practices, significant damage and numbers of fatalities can still occur. In this effort, we present a concept and approach to redirect and attenuate the ground motion amplitudes of earthquake surface waves by implementing an engineered subsurface seismic barrier. The barrier is comprised of a borehole array complex that impedes and diverts destructive surface waves (typically 2-10 km wavelengths). Computational 2D and 3D seismic wave propagation models developed at MIT Lincoln Laboratory suggest that the borehole array arrangement is critical to the redirection and self-interference reduction of broadband hazardous seismic waves in the vicinity of the structure to protect. For validity, the computational models are compared with data obtained from large bench-scale physical models that contain scaled borehole arrays and trenches. Small contact shakers generate elastic waves in solid media, while contact tri-axial accelerometer arrays measure the resultant wave fields. Field tests are presently being conducted to examine the seismic power reduction across a subsurface borehole array generated by controlled, far-field seismic sources. The sources include a weight drop and oriented seismic vibrational sources that generate low frequency surface and body waves. The pre-borehole condition at the site is measured first with a tri-axial geophone arrangement. The

  7. Borehole Optical Stratigraphy Modeling, Antarctica, Version 1 (United States)

    National Aeronautics and Space Administration — This data set consists of scripts and code designed for modeling the properties of boreholes in polar ice sheets, under a range of variations in the borehole...

  8. Imaging systems for geotechnical boreholes

    Energy Technology Data Exchange (ETDEWEB)

    Scott Thomson; S. Adam [CoalBed Concepts Pty Ltd. (Australia)


    The objective of this project was to develop a new system for evaluating geotechnical boreholes in underground mining. This approach was predicated on the demonstration of a commercial prototype imaging system (the Slim Borehole Scanner (SBS)) which is designed to be suitable for application in all standard geotechnical boreholes and is certified Intrinsically Safe (IS) in Europe. This project was designed to test this new imaging system in Australian conditions and critically compare the outcomes from the work with currently available technologies. A key aspect of the project was the assessment of the likely impact the imaging system has on current practices and recommendations for improved methods of geotechnical assessment in underground operations. A comprehensive field-testing program of the SBS was undertaken to evaluate its suitability for application in Australian conditions. Test work was completed at BHPB Illawarra Appin Colliery and Xstrata Coal Tahmoor Colliery. The Slim Borehole Scanner (SBS) was found to be a useful tool for enhancing the capability of Australian underground mine operators to assess roof conditions. The SBS is a significant advance on existing qualitative assessment methods such as the Borescope, and is complementary to existing direct measurement methods such as Tel-tales and Gel-extensometers. It is recommended that the SBS system undergo Australian intrinsic safety approval and be adopted as a routine part of the geotechnical engineer's arsenal in assessing roof control issues in Australian mines.

  9. High-Resolution Analysis of Seismicity Induced at Berlín Geothermal Field, El Salvador (United States)

    Kwiatek, G.; Bulut, F.; Dresen, G. H.; Bohnhoff, M.


    We investigate induced microseismic activity monitored at Berlín Geothermal Field, El Salvador, during a hydraulic stimulation. The site was monitored for a time period of 17 months using thirteen 3-component seismic stations located in shallow boreholes. Three stimulations were performed in the well TR8A with a maximum injection rate and well head pressure of 160l/s and 130bar, respectively. For the entire time period of our analysis, the acquisition system recorded 581 events with moment magnitudes ranging between -0.5 and 3.7. The initial seismic catalog provided by the operator was substantially improved: 1) We re-picked P- and S-wave onsets and relocated the seismic events using the double-difference relocation algorithm based on cross-correlation derived differential arrival time data. Forward modeling was performed using a local 1D velocity model instead of homogeneous full-space. 2) We recalculated source parameters using the spectral fitting method and refined the results applying the spectral ratio method. We investigated the source parameters and spatial and temporal changes of the seismic activity based on the refined dataset and studied the correlation between seismic activity and production. The achieved hypocentral precision allowed resolving the spatiotemporal changes in seismic activity down to a scale of a few meters. The application of spectral ratio method significantly improved the quality of source parameters in a high-attenuating and complex geological environment. Of special interest is the largest event (Mw3.7) and its nucleation process. We investigate whether the refined seismic data display any signatures that the largest event is triggered by the shut-in of the well. We found seismic activity displaying clear spatial and temporal patterns that could be easily related to the amount of water injected into the well TR8A and other reinjection wells in the investigated area. The migration of seismicity outside of injection point is observed

  10. Basic hydraulics

    CERN Document Server

    Smith, P D


    BASIC Hydraulics aims to help students both to become proficient in the BASIC programming language by actually using the language in an important field of engineering and to use computing as a means of mastering the subject of hydraulics. The book begins with a summary of the technique of computing in BASIC together with comments and listing of the main commands and statements. Subsequent chapters introduce the fundamental concepts and appropriate governing equations. Topics covered include principles of fluid mechanics; flow in pipes, pipe networks and open channels; hydraulic machinery;

  11. Hydraulic fracture monitoring in hard rock at 410 m depth with an advanced fluid-injection protocol and extensive sensor array (United States)

    Zang, Arno; Stephansson, Ove; Stenberg, Leif; Plenkers, Katrin; Specht, Sebastian; Milkereit, Claus; Schill, Eva; Kwiatek, Grzegorz; Dresen, Georg; Zimmermann, Günter; Dahm, Torsten; Weber, Michael


    In this paper, an underground experiment at the Äspö Hard Rock Laboratory (HRL) is described. Main goal is optimizing geothermal heat exchange in crystalline rock mass at depth by multistage hydraulic fracturing with minimal impact on the environment, that is, seismic events. For this, three arrays with acoustic emission, microseismicity and electromagnetic sensors are installed mapping hydraulic fracture initiation and growth. Fractures are driven by three different water injection schemes (continuous, progressive and pulse pressurization). After a brief review of hydraulic fracture operations in crystalline rock mass at mine scale, the site geology and the stress conditions at Äspö HRL are described. Then, the continuous, single-flow rate and alternative, multiple-flow rate fracture breakdown tests in a horizontal borehole at depth level 410 m are described together with the monitoring networks and sensitivity. Monitoring results include the primary catalogue of acoustic emission hypocentres obtained from four hydraulic fractures with the in situ trigger and localizing network. The continuous versus alternative water injection schemes are discussed in terms of the fracture breakdown pressure, the fracture pattern from impression packer result and the monitoring at the arrays. An example of multistage hydraulic fracturing with several phases of opening and closing of fracture walls is evaluated using data from acoustic emissions, seismic broad-band recordings and electromagnetic signal response. Based on our limited amount of in situ tests (six) and evaluation of three tests in Ävrö granodiorite, in the multiple-flow rate test with progressively increasing target pressure, the acoustic emission activity starts at a later stage in the fracturing process compared to the conventional fracturing case with continuous water injection. In tendency, also the total number and magnitude of acoustic events are found to be smaller in the progressive treatment with

  12. A novel muon detector for borehole density tomography (United States)

    Bonneville, Alain; Kouzes, Richard T.; Yamaoka, Jared; Rowe, Charlotte; Guardincerri, Elena; Durham, J. Matthew; Morris, Christopher L.; Poulson, Daniel C.; Plaud-Ramos, Kenie; Morley, Deborah J.; Bacon, Jeffrey D.; Bynes, James; Cercillieux, Julien; Ketter, Chris; Le, Khanh; Mostafanezhad, Isar; Varner, Gary; Flygare, Joshua; Lintereur, Azaree T.


    Muons can be used to image the density of materials through which they pass, including geological structures. Subsurface applications of the technology include tracking fluid migration during injection or production, with increasing concern regarding such timely issues as induced seismicity or chemical leakage into aquifers. Current density monitoring options include gravimetric data collection and active or passive seismic surveys. One alternative, or complement, to these methods is the development of a muon detector that is sufficiently compact and robust for deployment in a borehole. Such a muon detector can enable imaging of density structure to monitor small changes in density - a proxy for fluid migration - at depths up to 1500 m. Such a detector has been developed, and Monte Carlo modeling methods applied to simulate the anticipated detector response. Testing and measurements using a prototype detector in the laboratory and shallow underground laboratory demonstrated robust response. A satisfactory comparison with a large drift tube-based muon detector is also presented.

  13. Hydraulic Structures (United States)

    Department of Homeland Security — This table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the FIRM, channels containing the...

  14. Laboratory Visualization Experiments of Temperature-induced Fractures Around a Borehole (Cryogenic Fracturing) in Shale and Analogue Rock Samples (United States)

    Kneafsey, T. J.; Nakagawa, S.; Wu, Y. S.; Mukhopadhyay, S.


    In tight shales, hydraulic fracturing is the dominant method for improving reservoir permeability. However, injecting water-based liquids can induce formation damage and disposal problems, thus other techniques are being sought. One alternative to hydraulic fracturing is producing fractures thermally, using low-temperature fluids (cryogens). The primary consequence of thermal stimulation is that shrinkage fractures are produced around the borehole wall. Recently, cryogenic stimulation produced some promising results when the cryogen (typically liquid nitrogen and cold nitrogen gas) could be brought to reservoir depth. Numerical modeling also showed possible significant increases in gas production from a shale reservoir after cryogenic stimulation. However, geometry and the dynamic behavior of these thermally induced fractures under different stress regimes and rock anisotropy and heterogeneity is not yet well understood.Currently, we are conducting a series of laboratory thermal fracturing experiments on Mancos Shale and transparent glass blocks, by injecting liquid nitrogen under atmospheric pressure into room temperature blocks under various anisotropic stress states. The glass blocks allow clear optical visualization of fracture development and final fracturing patterns. For the shale blocks, X-ray CT is used to image both pre-existing and induced fractures. Also, the effect of borehole orientation with respect to the bedding planes and aligned preexisting fractures is examined. Our initial experiment on a uniaxially compressed glass block showed fracturing behavior which was distinctly different from conventional hydraulic fracturing. In addition to tensile fractures in the maximum principal stress directions, the thermal contraction by the cryogen induced (1) chaotic, spalling fractures around the borehole wall, and (2) a series of disk-shaped annular fractures perpendicular to the borehole. When applied to a horizontal borehole, the propagation plane of the

  15. Integrating Seismic Reflection and Ground Penetrating Radar Data at the Marine Corps Air Station, Beaufort, South Carolina (United States)

    Addison, A. D.; Knapp, C. C.; Waddell, M. G.


    Extensive work has been performed at the Marine Corps Air Station (MCAS) in Beaufort South Carolina to characterize the subsurface and generate a groundwater flow model for an assessment of MCAS aquifer vulnerability and contamination potential using various hydrogeological and geophysical techniques such as slug tests, vertical seismic profiling (VSP), borehole geophysics, vertical electrical soundings, and seismic reflection surveys. The goal of the additional research is to integrate the existing seismic reflection data with newly acquired GPR data in order to: (1) demonstrate the effectiveness of the GPR as a tool for site characterization and (2) obtain hydrogeophysical parameters in a heterogeneous environment. The primary focus of the MCAS Beaufort groundwater flow model is to understand the interaction between the unconsolidated clastic Pleistocene sediments and the underlying Eocene Ocala Limestone, which is the primary aquifer. GPR data were collected along the transect of seismic reflection line MCAS-2 which is a total length of approximately 1700 m with a recording length of 500 ms. There are several wells along the profile that were utilized for hydrogeological and geophysical calibration. Preliminary GPR data were collected adjacent to ground water monitor well BFT-2368, using the 50 and 100 MHz frequency antennas, and consisted of three reflection profiles that vary in length from approximately 210 to 240 m. Comparison of the GPR and seismic data illustrate that the two applications complement one another with respect to resolution. Where GPR data contain better detail (more continuous reflectors) in the shallow subsurface, the seismic data contain less detail but deeper reflections. We are using the seismic attributes such as acoustic impedance, and the dielectric properties estimated from the GPR data in order to make assessments on hydrogeological parameters such as porosity and further, hydraulic conductivity.

  16. Monitoring hydrofrac-induced seismicity by surface arrays - the DHM-Project Basel case study (United States)

    Blascheck, P.; Häge, M.; Joswig, M.


    The method "nanoseismic monitoring" was applied during the hydraulic stimulation at the Deep-Heat-Mining-Project (DHM-Project) Basel. Two small arrays in a distance of 2.1 km and 4.8 km to the borehole recorded continuously for two days. During this time more than 2500 seismic events were detected. The method of the surface monitoring of induced seismicity was compared to the reference which the hydrofrac monitoring presented. The latter was conducted by a network of borehole seismometers by Geothermal Explorers Limited. Array processing provides a outlier resistant, graphical jack-knifing localization method which resulted in a average deviation towards the reference of 850 m. Additionally, by applying the relative localization master-event method, the NNW-SSE strike direction of the reference was confirmed. It was shown that, in order to successfully estimate the magnitude of completeness as well as the b-value at the event rate and detection sensibility present, 3 h segments of data are sufficient. This is supported by two segment out of over 13 h of evaluated data. These segments were chosen so that they represent a time during the high seismic noise during normal working hours in daytime as well as the minimum anthropogenic noise at night. The low signal-to-noise ratio was compensated by the application of a sonogram event detection as well as a coincidence analysis within each array. Sonograms allow by autoadaptive, non-linear filtering to enhance signals whose amplitudes are just above noise level. For these events the magnitude was determined by the master-event method, allowing to compute the magnitude of completeness by the entire-magnitude-range method provided by the ZMAP toolbox. Additionally, the b-values were determined and compared to the reference values. An introduction to the method of "nanoseismic monitoring" will be given as well as the comparison to reference data in the Basel case study.

  17. A detailed comparison of laboratory and borehole NMR estimated parameters in unconsolidated aquifers (United States)

    Behroozmand, A. A.; Auken, E.; Christiansen, A. V.; Müller-Petke, M.; Johnson, C. D.; Vilhelmsen, T. N.; Barfod, A. A. S.; Ferré, T. P. A.; Knight, R. J.


    Borehole nuclear magnetic resonance (NMR) measurements can be used to obtain information about the hydrologic properties of unconsolidated aquifers. The NMR estimated parameters, water content and relaxation time, can be linked to hydraulic conductivity (K). In unconsolidated aquifers, attempts have been made to establish the NMR-K relationship by acquiring NMR and K data in boreholes. However, it is challenging in unconsolidated aquifers to obtain reliable estimates of the NMR parameters from borehole data. The aquifer formation can be altered due to severe washout during drilling and there can be a large disturbed zone around the PVC casing. Laboratory-NMR data could be used to assist in the development of reliable NMR-K models, as is typically done in the petroleum industry. The challenge has been obtaining high quality laboratory samples, from unconsolidated aquifers. In this study, we present a detailed comparison of laboratory and borehole NMR data at a study site in Denmark. To address the challenges with both laboratory and borehole measurements in unconsolidated aquifers, we drilled a borehole using a sonic rig that minimally disturbs the formation and produces essentially no disturbed zone around the PVC casing, thus providing ideal conditions for borehole NMR measurements. Moreover, continuous undisturbed samples, 3 in in diameter, were obtained for the entire depth of the borehole, 32 m. These samples are excellent for the laboratory NMR measurements because they are representative of in-situ conditions. With this drilling method we obtained reliable borehole NMR results that are supported by other logging data and lithologic description of the cores. In addition, we successfully acquired laboratory-NMR data that are in excellent agreement with our borehole NMR estimated parameters. This study provides insights into the impact of sample size and condition on laboratory measurements. Laboratory measurements of hydraulic conductivity were made in an

  18. Delineation of faults, fractures, foliation, and ground-water-flow zones in fractured-rock, on the southern part of Manhattan, New York, through use of advanced borehole-geophysical techniques (United States)

    Stumm, Frederick; Chu, Anthony; Monti, Jack


    Advanced borehole-geophysical techniques were used to assess the geohydrology of crystalline bedrock in 20 boreholes on the southern part of Manhattan Island, N.Y., in preparation for construction of a third water tunnel for New York City. The borehole-logging techniques included natural gamma, single-point resistance, short-normal resistivity, mechanical and acoustic caliper, magnetic susceptibility, borehole-fluid temperature and resistivity, borehole-fluid specific conductance, dissolved oxygen, pH, redox, heatpulse flowmeter (at selected boreholes), borehole deviation, acoustic and optical televiewer, and borehole radar (at selected boreholes). Hydraulic head and specific-capacity test data were collected from 29 boreholes. The boreholes penetrated gneiss, schist, and other crystalline bedrock that has an overall southwest to northwest-dipping foliation. Most of the fractures penetrated are nearly horizontal or have moderate- to high-angle northwest or eastward dip azimuths. Foliation dip within the potential tunnel-construction zone is northwestward and southeastward in the proposed North Water-Tunnel, northwestward to southwestward in the proposed Midtown Water-Tunnel, and northwestward to westward dipping in the proposed South Water-Tunnel. Fracture population dip azimuths are variable. Heat-pulse flowmeter logs obtained under pumping and nonpumping (ambient) conditions, together with other geophysical logs, indicate transmissive fracture zones in each borehole. The 60-megahertz directional borehole-radar logs delineated the location and orientation of several radar reflectors that did not intersect the projection of the borehole.Fracture indexes range from 0.12 to 0.93 fractures per foot of borehole. Analysis of specific-capacity tests from each borehole indicated that transmissivity ranges from 2 to 459 feet squared per day; the highest transmissivity is at the Midtown Water-Tunnel borehole (E35ST-D).

  19. Determination of hydraulic characteristics of an aquifer capacity from ...

    African Journals Online (AJOL)

    Constant rate, single well pumping tests were conducted using boreholes located in four communities in the study area with the aim of determining the aquifer hydraulic properties using the Cooper Jacob method. Fractured shales yielded groundwater into the wells whose depths ranged from 26 to 35m while the static water ...

  20. An automated method to build groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs

    DEFF Research Database (Denmark)

    Marker, Pernille Aabye; Foged, N.; He, X.


    -scale groundwater models. We present a novel method to automatically integrate large AEM data-sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models...... of electrical resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study...

  1. Geohydrology of the Stockton Formation and cross-contamination through open boreholes, Hatboro Borough and Warminster Township, Pennsylvania (United States)

    Sloto, R.A.; Macchiaroli, Paola; Towle, M.T.


    The study area consists of a 9-square-mile area underlain by sedimentary rocks of the middle arkose member of the Stockton Formation of Upper Triassic age. In the Hatboro area, the Stockton Formation strikes approximately N. 65 degrees E. and dps approximately 9 degrees NW. The rocks are chiefly arkosic sandstone and siltstone. Rocks of the Stocton Formation form a complex, heterogeneous, multiaquifer system consisting of a series of gently dipping lithologic units with different hydraulic properties. Most ground water in the unweathered zone moves through a network of interconnecting secondary openigns-fractures, bedding plans, and joints. Ground water is unconfined in the shallower part of the aquifer and semiconfined or confined in the deeper part of the aquifer. Nearly all deep wells in the Stockton Formation are open to several water-bearing zones and are multiaquifer wells. Each water-bearing zone usually has a different hydraulic head. Where differences in hydraulic head exist between water-bearing zones, water in the well bore flows under nonpumping conditions in the direction of decreasing head. Determination of the potential for borehole flow was based on caliper, natural-gamma, single- point-resistance, fluid-resistivity, and (or) fluid-temperature logs that were run in 162 boreholes 31 to 655 feet deep. The direction and rate of borehole-fluid movement were determined in 83 boreholes by the bring-tracing method and in 10 boreholes by use of a heat-pulse flowmeter. Borehole flow was measurable in 65 of the 93 boreholes (70 percent). Fluid movement at rates up to 17 gallons per minute was measured. Downward flow was measured in 36 boreholes, and upward flow was measured in 23 boreholes, not including those boreholes in which two directions of flow were measured. Both upward and downward vertical flow was measured in six boreholes; these boreholes are 396 to 470 feet deep and were among the deepest boreholes logged. Fluid movement was upward in the upper

  2. A multi-scale case study of natural fracture systems in outcrops and boreholes with applications to reservoir modelling

    NARCIS (Netherlands)

    Taal-van Koppen, J.K.J.


    Fractured reservoirs are notoriously difficult to characterize because the resolution of seismic data is too low to detect fractures whereas borehole data is detailed but sparse. Therefore, outcrops can be of great support in gaining knowledge of the three-dimensional geometry of fracture networks,

  3. SNG-log in borehole Ermelund-208

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C


    A Spectral Natural Gamma-ray log has been run in a borehole in Ermelunden. The vertical distribution of Th, U, and K is similar to that observed in neighbouring boreholes. A new measuring and data processing technique was used and the probes own background signal was determined. Surprisingly...

  4. Seismic isolation for Advanced LIGO

    CERN Document Server

    Abbott, R; Allen, G; Cowley, S; Daw, E; Debra, D; Giaime, J; Hammond, G; Hammond, M; Hardham, C; How, J; Hua, W; Johnson, W; Lantz, B; Mason, K; Mittleman, R; Nichol, J; Richman, S; Rollins, J; Shoemaker, D; Stapfer, G; Stebbins, R


    The baseline design concept for a seismic isolation component of the proposed 'Advanced LIGO' detector upgrade has been developed with proof-of-principle experiments and computer models. It consists of a two-stage in-vacuum active isolation platform that is supported by an external hydraulic actuation stage. Construction is underway for prototype testing of a full-scale preliminary design.


    Energy Technology Data Exchange (ETDEWEB)

    Erik C. Westman


    Improved ground-imaging capabilities have enormous potential to increase energy, environmental, and economic benefits by improving exploration accuracy and reducing energy consumption during the mining cycle. Seismic tomography has been used successfully to monitor and evaluate geologic conditions ahead of a mining face. A primary limitation to existing seismic tomography, however, is the placement of sensors. The goal of this project is to develop an array of 24 seismic sensors capable of being mounted in either a vertical or horizontal borehole. Development of this technology reduces energy usage in excavation, transportation, ventilation, and processing phases of the mining operation because less waste is mined and the mining cycle suffers fewer interruptions. This new technology benefits all types of mines, including metal/nonmetal, coal, and quarrying. The primary research tasks focused on sensor placement method, sensor housing and clamping design, and cabling and connector selection. An initial design is described in the report. Following assembly, a prototype was tested in the laboratory as well as at a surface stone quarry. Data analysis and tool performance were used for subsequent design modifications. A final design is described, of which several components are available for patent application. Industry partners have shown clear support for this research and demonstrated an interest in commercialization following project completion.

  6. Deep Borehole Disposal Safety Analysis.

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, Geoffrey A. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Stein, Emily [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Price, Laura L. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); MacKinnon, Robert J. [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States); Tillman, Jack Bruce [Sandia National Laboratories (SNL-NM), Albuquerque, NM (United States)


    This report presents a preliminary safety analysis for the deep borehole disposal (DBD) concept, using a safety case framework. A safety case is an integrated collection of qualitative and quantitative arguments, evidence, and analyses that substantiate the safety, and the level of confidence in the safety, of a geologic repository. This safety case framework for DBD follows the outline of the elements of a safety case, and identifies the types of information that will be required to satisfy these elements. At this very preliminary phase of development, the DBD safety case focuses on the generic feasibility of the DBD concept. It is based on potential system designs, waste forms, engineering, and geologic conditions; however, no specific site or regulatory framework exists. It will progress to a site-specific safety case as the DBD concept advances into a site-specific phase, progressing through consent-based site selection and site investigation and characterization.

  7. Mechanics and direction of hydraulic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Daneshy, A.A.


    Use of the in situ principal stresses greatly simplifies the problems of hydraulic fracturing. For one thing, it reduces the number of stresses to 3, thus simplifying the mathematics. Besides, this choice is in harmony with laboratory observations of fracture propagation perpendicular to the least principal stress. In addition to underground stresses, hydraulic stress is also influenced by the mechanical properties of the formation rock. In this discussion, it is assumed that the formation to be fractured is isotropic, homogeneous, and brittle-elastic. The initiation of hydraulic fractures is synonymous with the rupture of rock adjacent to the borehole wall. This rupture can occur only if the induced stresses exceed the strength of the formation. During fracturing treatments, fracture initiation is identified by a sudden drop in borehole fluid pressure accompanied by an increase in the injection rate. Continued injection of fluid after fracture initiation will result in its extension. The fracture will propagate in such a way that it will require the least possible amount of energy for its extension.

  8. Use of advanced borehole geophysical techniques to delineate fractured-rock ground-water flow and fractures along water-tunnel facilities in northern Queens County, New York (United States)

    Stumm, Frederick; Chu, Anthony; Lange, Andrew D.; Paillet, Frederick L.; Williams, John H.; Lane, John W.


    Advanced borehole geophysical methods were used to assess the geohydrology of crystalline bedrock along the course of a new water tunnel for New York City. The logging methods include natural gamma, spontaneous potential, single-point resistance, mechanical and acoustic caliper, focused electromagnetic induction, electromagnetic resistivity, magnetic susceptibility, borehole-fluid temperature and conductance, differential temperature, heat-pulse flowmeter, acoustic televiewer, borehole deviation, optical televiewer, and borehole radar. Integrated interpretation of the geophysical logs from an 825-foot borehole (1) provided information on the extent, orientation, and structure (foliation and fractures) within the entire borehole, including intensely fractured intervals from which core recovery may be poor; (2) delineated transmissive fracture zones intersected by the borehole and provided estimates of their transmissivity and hydraulic head; and (3) enabled mapping of the location and orientation of structures at distances as much as 100 ft from the borehole.Analyses of the borehole-wall image and the geophysical logs from the borehole on Crescent Street, in northern Queens County, are presented here to illustrate the application of the methods. The borehole penetrates gneiss and other crystalline bedrock that has predominantly southeastward dipping foliation and nearly horizontal and southeastward-dipping fractures. The heat-pulse flowmeter logs obtained under pumping and nonpumping conditions, together with the other geophysical logs, indicate five transmissive fracture zones. More than 90 percent of the open-hole transmissivity is associated with a fracture zone 272 feet BLS (below land surface). A transmissive zone at 787 feet BLS that consists of nearly parallel fractures lies within the projected tunnel path; here the hydraulic head is 12 to 15 feet lower than that of transmissive zones above the 315-foot depth. The 60-megahertz directional borehole radar logs

  9. High energy gas fracture experiments in liquid-filled boreholes: potential geothermal application

    Energy Technology Data Exchange (ETDEWEB)

    Cuderman, J.F.; Chu, T.Y.; Jung, J.; Jacobson, R.D.


    High Energy Gas Fracturing is a tailored pulse fracturing technique which uses propellants to obtain controlled fracture initiation and extension. Borehole pressurization rates can be tailored, by suitable choice of propellants, to produce four or eight fractures radiating from the wellbore. High Energy Gas Fracture (HEGF) research is conducted at DOE's Nevada Test Site (NTS) in a tunnel complex where experiments can be done under realistic in situ stress conditions (1400 psi (9.7 MPa) overburden stress). Pressure measurements are made in the test borehole during all fracturing experiments. Experiments are mined back to provide direct observation of fracturing obtained. The initial objective of HEGF research was to develop multiple fracturing technology for application in gas well stimulation. HEGF research at NTS and in Devonian shale demonstration tests has resulted in a completed technology for multiple fracturing in uncased, liquid-free wellbores. Current resarch is directed toward extending the technique to liquid-filled boreholes for application in geothermal in addition to gas and oil wells. For liquid-free boreholes, multiple fracturing is specified in terms of pressure risetime required for a given borehole diameter. Propellants are mixed to achieve the desired risetime using a semiempirical mixing equation. The same techniques were successfully applied to fracturing in liquid-filled wellbores. However, the addition of liquid in the borehole results in a significantly more complicated fracturing behavior. Hydrodynamic effects are significant. Multiple fractures are initiated but only some propagated. Multiple- and hydraulic-type fracturing and wellbore crushing have been observed in the same experiment. The potential of using HEGB for geothermal well stimulation has been demonstrated through the present experiments. 18 refs., 40 figs., 4 tabs.

  10. Vertical cross contamination of trichloroethylene in a borehole in fractured sandstone (United States)

    Sterling, S.N.; Parker, B.L.; Cherry, J.A.; Williams, J.H.; Lane, J.W.; Haeni, F.P.


    Boreholes drilled through contaminated zones in fractured rock create the potential for vertical movement of contaminated ground water between fractures. The usual assumption is that purging eliminates cross contamination; however, the results of a field study conducted in a trichloroethylene (TCE) plume in fractured sandstone with a mean matrix porosity of 13% demonstrates that matrix-diffusion effects can be strong and persistent. A deep borehole was drilled to 110 m below ground surface (mbgs) near a shallow bedrock well containing high TCE concentrations. The borehole was cored continuously to collect closely spaced samples of rock for analysis of TCE concentrations. Geophysical logging and flowmetering were conducted in the open borehole, and a removable multilevel monitoring system was installed to provide hydraulic-head and ground water samples from discrete fracture zones. The borehole was later reamed to complete a well screened from 89 to 100 mbgs; persistent TCE concentrations at this depth ranged from 2100 to 33,000 ??g/L. Rock-core analyses, combined with the other types of borehole information, show that nearly all of this deep contamination was due to the lingering effects of the downward flow of dissolved TCE from shallower depths during the few days of open-hole conditions that existed prior to installation of the multilevel system. This study demonstrates that transfer of contaminant mass to the matrix by diffusion can cause severe cross contamination effects in sedimentary rocks, but these effects generally are not identified from information normally obtained in fractured-rock investigations, resulting in potential misinterpretation of site conditions. Copyright ?? 2005 National Ground Water Association.

  11. Borehole Deformation and Failure in Anisotropic Media (United States)

    Gaede, Oliver; Regenauer-Lieb, Klaus; Lumley, David


    Borehole breakouts develop due to compressive shear failure along the borehole wall and subsequent spalling of near wellbore rock. These compressive shear failures can occur during drilling and lead to a borehole enlargement in the direction of the minimum horizontal stress. In order to investigate the initiation of borehole breakouts in anisotropic media a numerical analysis of the borehole deformation has been performed. The numerical model is based on an extensive geophysical and geomechanical dataset, provided by BHP Billiton Petroleum. This dataset was established during the development and production phase of an oil reservoir on the North West Shelf, Western Australia. The aim of this study is to estimate the severity of the influence of anisotropy on the breakout process. It is proposed that there is a hierarchy among the possible influences on the breakout process: 1. The regional stress field has a first order effect on the borehole breakout direction. 2. This is followed by a preferential fracture direction or anisotropic failure criterion of the medium. 3. And finally the elastic anisotropy of the medium affecting the local stress field around the borehole. A clear separation of these influences through methods of observation is not always trivial. Firstly, the preferential fracture direction and the elastic anisotropy, at least to some degree, are functions of the regional stress field. Secondly, most of the knowledge we have about the regional stress field in relatively aseismic regions is inferred from borehole breakout data. Therefore a numerical simulation is chosen as a method of study. Material properties like elastic anisotropy or failure criterion and even their dependency on the stress field can easily be manipulated. This geophysical and geomechanical data is used to populate the numerical model. The regional stress field is implemented as a boundary condition. The commercial Finite Element package ABAQUS is used to obtain the stress / strain

  12. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 2. Preliminary outcomes from hot-water drilling and borehole instrumentation on Store Glacier, West Greenland (United States)

    Doyle, Samuel; Hubbard, Bryn; Christoffersen, Poul; Young, Tun Jan; Hofstede, Coen; Todd, Joe; Bougamont, Marion; Hubbard, Alun


    As part of the SAFIRE research programme, pressurised hot water was used to drill four 603-616 m-long boreholes to the bed of the Greenland Ice Sheet at a site located 30 km from the calving front of marine-terminating Store Glacier (70° N, ~1000 m elevation). Despite the boreholes freezing within hours, 4 wired sensor strings were successfully deployed in three of the boreholes. These included a thermistor string to obtain the englacial temperature profile installed in the same borehole as a string of tilt sensors to measure borehole deformation, and two sets of water pressure, electrical conductivity and turbidity sensors installed just above the bed in separate, adjacent boreholes. The boreholes made a strong hydrological connection to the bed during drilling, draining rapidly to ~80 m below the ice surface. The connection of subsequent boreholes was observed as a perturbation in water pressure and temperature recorded in neighbouring boreholes, indicating an effective hydrological sub- or en-glacial connection between them. The short (week long) records obtained from these sensors in summer 2014 tentatively reveal (i) water pressure varying diurnally close to overburden albeit of a small magnitude (~0.3 m H2O), (ii) a minimum extrapolated englacial temperature of -21° C, (iii) and thermistors in the lowest 10 m of the borehole recorded temperatures above the pressure melting point indicating the presence of water. Data loggers were left running and longer records should become available in the near future. Differential drilling and instrument installation depths together with observations of discrete, diurnal turbidity events provisionally suggest the presence of sediment at the bed. These preliminary borehole observations will be complemented by GPS measurements of ice motion, meteorological data, and seismic and radar surveys to be undertaken over the next two years.

  13. Dimensioning of Boreholes for Geothermal Heat Pumps

    Directory of Open Access Journals (Sweden)

    Ryška Jiøí


    Full Text Available The paper deals with determination of borehole depths for geothermal heat pumps. Basic formulae are stated for heat convection in rocks. Software EED 2.0 was used for calculation of borehole depth depending on different entering parameters. The crucial parameter is thermal conductivity of rocks. The thermal conductivity could be very variable for the same kind of rock. Therefore its in-situ determination by means of formation thermal conductivity testing is briefly described.

  14. Using boreholes as windows into groundwater ecosystems.

    Directory of Open Access Journals (Sweden)

    James P R Sorensen

    Full Text Available Groundwater ecosystems remain poorly understood yet may provide ecosystem services, make a unique contribution to biodiversity and contain useful bio-indicators of water quality. Little is known about ecosystem variability, the distribution of invertebrates within aquifers, or how representative boreholes are of aquifers. We addressed these issues using borehole imaging and single borehole dilution tests to identify three potential aquifer habitats (fractures, fissures or conduits intercepted by two Chalk boreholes at different depths beneath the surface (34 to 98 m. These habitats were characterised by sampling the invertebrates, microbiology and hydrochemistry using a packer system to isolate them. Samples were taken with progressively increasing pumped volume to assess differences between borehole and aquifer communities. The study provides a new conceptual framework to infer the origin of water, invertebrates and microbes sampled from boreholes. It demonstrates that pumping 5 m(3 at 0.4-1.8 l/sec was sufficient to entrain invertebrates from five to tens of metres into the aquifer during these packer tests. Invertebrates and bacteria were more abundant in the boreholes than in the aquifer, with associated water chemistry variations indicating that boreholes act as sites of enhanced biogeochemical cycling. There was some variability in invertebrate abundance and bacterial community structure between habitats, indicating ecological heterogeneity within the aquifer. However, invertebrates were captured in all aquifer samples, and bacterial abundance, major ion chemistry and dissolved oxygen remained similar. Therefore the study demonstrates that in the Chalk, ecosystems comprising bacteria and invertebrates extend from around the water table to 70 m below it. Hydrogeological techniques provide excellent scope for tackling outstanding questions in groundwater ecology, provided an appropriate conceptual hydrogeological understanding is applied.

  15. Modeling of Hydraulic Fracture Propagation at the kISMET Site Using a Fully Coupled 3D Network-Flow and Quasi- Static Discrete Element Model

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Jing [Idaho National Lab. (INL), Idaho Falls, ID (United States); Huang, Hai [Idaho National Lab. (INL), Idaho Falls, ID (United States); Mattson, Earl [Idaho National Lab. (INL), Idaho Falls, ID (United States); Wang, Herb F. [Univ. of Wisconsin, Madison, WI (United States); Haimson, Bezalel C. [Univ. of Wisconsin, Madison, WI (United States); Doe, Thomas W. [Golder Associates Inc., Redmond, VA (United States); Oldenburg, Curtis M. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Dobson, Patrick F. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    Aimed at supporting the design of hydraulic fracturing experiments at the kISMET site, ~1500 m below ground in a deep mine, we performed pre-experimental hydraulic fracturing simulations in order to estimate the breakdown pressure, propagation pressure, fracture geometry, and the magnitude of induced seismicity using a newly developed fully coupled three-dimensional (3D) network flow and quasi-static discrete element model (DEM). The quasi-static DEM model, which is constructed by Delaunay tessellation of the rock volume, considers rock fabric heterogeneities by using the “disordered” DEM mesh and adding random perturbations to the stiffness and tensile/shear strengths of individual DEM elements and the elastic beams between them. A conjugate 3D flow network based on the DEM lattice is constructed to calculate the fluid flow in both the fracture and porous matrix. One distinctive advantage of the model is that fracturing is naturally described by the breakage of elastic beams between DEM elements. It is also extremely convenient to introduce mechanical anisotropy into the model by simply assigning orientation-dependent tensile/shear strengths to the elastic beams. In this paper, the 3D hydraulic fracturing model was verified against the analytic solution for a penny-shaped crack model. We applied the model to simulate fracture propagation from a vertical open borehole based on initial estimates of rock mechanical properties and in-situ stress conditions. The breakdown pressure and propagation pressure are directly obtained from the simulation. In addition, the released elastic strain energies of individual fracturing events were calculated and used as a conservative estimate for the magnitudes of the potential induced seismic activities associated with fracturing. The comparisons between model predictions and experimental results are still ongoing.

  16. Borehole flowmeter logging for the accurate design and analysis of tracer tests. (United States)

    Basiricò, Stefano; Crosta, Giovanni B; Frattini, Paolo; Villa, Alberto; Godio, Alberto


    Tracer tests often give ambiguous interpretations that may be due to the erroneous location of sampling points and/or the lack of flow rate measurements through the sampler. To obtain more reliable tracer test results, we propose a methodology that optimizes the design and analysis of tracer tests in a cross borehole mode by using vertical borehole flow rate measurements. Experiments using this approach, herein defined as the Bh-flow tracer test, have been performed by implementing three sequential steps: (1) single-hole flowmeter test, (2) cross-hole flowmeter test, and (3) tracer test. At the experimental site, core logging, pumping tests, and static water-level measurements were previously carried out to determine stratigraphy, fracture characteristics, and bulk hydraulic conductivity. Single-hole flowmeter testing makes it possible to detect the presence of vertical flows as well as inflow and outflow zones, whereas cross-hole flowmeter testing detects the presence of connections along sets of flow conduits or discontinuities intercepted by boreholes. Finally, the specific pathways and rates of groundwater flow through selected flowpaths are determined by tracer testing. We conclude that the combined use of single and cross-borehole flowmeter tests is fundamental to the formulation of the tracer test strategy and interpretation of the tracer test results. © 2014, National Ground Water Association.

  17. Wind seismic noise introduced by external infrastructure: field data and transfer mechanism (United States)

    Martysevich, Pavel; Starovoyt, Yuri


    Background seismic noise generated by wind was analyzed at six co-located seismic and infrasound arrays with the use of the wind speed data. The main factors affecting the noise level were identified as (a) external structures as antenna towers for intrasite communication, vegetation and heavy solar panels fixtures, (b) borehole casing and (c) local lithology. The wind-induced seismic noise peaks in the spectra can be predicted by combination of inverted pendulum model for antenna towers and structures used to support solar panels, free- or clamped-tube resonance of the borehole casing and is dependent on the type of sedimentary upper layer. Observed resonance frequencies are in agreement with calculated clamped / free tube modes for towers and borehole casings. Improvement of the seismic data quality can be achieved by minimizing the impact of surrounding structures close to seismic boreholes. The need and the advantage of the borehole installation may vanish and appear to be even not necessary at locations with non-consolidated sediments because the impact of surrounding structures on seismic background may significantly deteriorate the installation quality and therefore the detection capability of the array. Several IMS arrays where the radio telemetry antennas are used for data delivery to the central site may benefit from the redesign of the intrasite communication system by its substitute with the fiber-optic net as less harmful engineering solution.

  18. A novel muon detector for borehole density tomography

    Energy Technology Data Exchange (ETDEWEB)

    Bonneville, Alain; Kouzes, Richard T.; Yamaoka, Jared; Rowe, Charlotte; Guardincerri, Elena; Durham, J. Matthew; Morris, Christopher L.; Poulson, Daniel C.; Plaud-Ramos, Kenie; Morley, Deborah J.; Bacon, Jeffrey D.; Bynes, James; Cercillieux, Julien; Ketter, Chris; Le, Khanh; Mostafanezhad, Isar; Varner, Gary; Flygare, Joshua; Lintereur, Azaree T.


    Muons can be used to image the density of materials through which they pass, including geological structures. Subsurface applications of the technology include tracking fluid migration during injection or production, with increasing concern regarding such timely issues as induced seismicity or chemical leakage into aquifers. Geological carbon storage, natural gas storage, enhanced oil recovery, compressed air storage, aquifer storage and recovery, waste water storage and oil and gas production are examples of application areas. It is thus crucial to monitor in quasi-real time the behavior of these fluids, and several monitoring techniques can be used. Among them, those that track density changes in the subsurface are the most relevant. Current density monitoring options include gravimetric data collection and active or passive seismic surveys. One alternative, or complement, to these methods is the development of a muon detector that is sufficiently compact and robust for deployment in a borehole. Such a muon detector can enable tomographic imaging of density structure to monitor small changes in density – a proxy for fluid migration – at depths up to 1500 m. Such a detector has been developed, and Monte Carlo modeling methods applied to simulate the anticipated detector response. The robustness of the detector design comes primarily from the use of polystyrene scintillating rods arrayed in alternating layers to provide a coordinate scheme. Testing and measurements using a prototype detector in the laboratory and shallow underground facilities demonstrated robust response. A satisfactory comparison with a large drift tube-based muon detector is also presented.

  19. Interpretation of hydraulic conductivity in a fractured-rock aquifer over increasingly larger length dimensions (United States)

    Shapiro, Allen M.; Ladderud, Jeffery; Yager, Richard M.


    A comparison of the hydraulic conductivity over increasingly larger volumes of crystalline rock was conducted in the Piedmont physiographic region near Bethesda, Maryland, USA. Fluid-injection tests were conducted on intervals of boreholes isolating closely spaced fractures. Single-hole tests were conducted by pumping in open boreholes for approximately 30 min, and an interference test was conducted by pumping a single borehole over 3 days while monitoring nearby boreholes. An estimate of the hydraulic conductivity of the rock over hundreds of meters was inferred from simulating groundwater inflow into a kilometer-long section of a Washington Metropolitan Area Transit Authority tunnel in the study area, and a groundwater modeling investigation over the Rock Creek watershed provided an estimate of the hydraulic conductivity over kilometers. The majority of groundwater flow is confined to relatively few fractures at a given location. Boreholes installed to depths of approximately 50 m have one or two highly transmissive fractures; the transmissivity of the remaining fractures ranges over five orders of magnitude. Estimates of hydraulic conductivity over increasingly larger rock volumes varied by less than half an order of magnitude. While many investigations point to increasing hydraulic conductivity as a function of the measurement scale, a comparison with selected investigations shows that the effective hydraulic conductivity estimated over larger volumes of rock can either increase, decrease, or remain stable as a function of the measurement scale. Caution needs to be exhibited in characterizing effective hydraulic properties in fractured rock for the purposes of groundwater management.

  20. Imaging CO2 reservoirs using muons borehole detectors (United States)

    Bonneville, A.; Bonal, N.; Lintereur, A.; Mellors, R. J.; Paulsson, B. N. P.; Rowe, C. A.; Varner, G. S.; Kouzes, R.; Flygare, J.; Mostafanezhad, I.; Yamaoka, J. A. K.; Guardincerri, E.; Chapline, G.


    Monitoring of the post-injection fate of CO2 in subsurface reservoirs is of utmost importance. Generally, monitoring options are active methods, such as 4D seismic reflection or pressure measurements in monitoring wells. We present a method of 4D density tomography of subsurface CO2 reservoirs using cosmic-ray muon detectors deployed in a borehole. Although muon flux rapidly decreases with depth, preliminary analyses indicate that the muon technique is sufficiently sensitive to effectively map density variations caused by fluid displacement at depths consistent with proposed CO2reservoirs. The intensity of the muon flux is, to first order, inversely proportional to the density times the path length, with resolution increasing with measurement time. The primary technical challenge preventing deployment of this technology in subsurface locations is the lack of miniaturized muon-tracking detectors both capable of fitting in standard boreholes and that will be able to resist the harsh underground conditions (temperature, pressure, corrosion) for long periods of time. Such a detector with these capabilities has been developed through a collaboration supported by the U.S. Department of Energy. A prototype has been tested in underground laboratories during 2016. In particular, we will present results from a series of tests performed in a tunnel comparing efficiencies, and angular and position resolution to measurements collected at the same locations by large instruments developed by Los Alamos and Sandia National Laboratories. We will also present the results of simulations of muon detection for various CO2 reservoir situations and muon detector configurations. Finally, to improve imaging of 3D subsurface structures, a combination of seismic data, gravity data, and muons can be used. Because seismic waves, gravity anomalies, and muons are all sensitive to density, the combination of two or three of these measurements promises to be a powerful way to improve spatial

  1. Geostatistical methods for rock mass quality prediction using borehole and geophysical survey data (United States)

    Chen, J.; Rubin, Y.; Sege, J. E.; Li, X.; Hehua, Z.


    For long, deep tunnels, the number of geotechnical borehole investigations during the preconstruction stage is generally limited. Yet tunnels are often constructed in geological structures with complex geometries, and in which the rock mass is fragmented from past structural deformations. Tunnel Geology Prediction (TGP) is a geophysical technique widely used during tunnel construction in China to ensure safety during construction and to prevent geological disasters. In this paper, geostatistical techniques were applied in order to integrate seismic velocity from TGP and borehole information into spatial predictions of RMR (Rock Mass Rating) in unexcavated areas. This approach is intended to apply conditional probability methods to transform seismic velocities to directly observed RMR values. The initial spatial distribution of RMR, inferred from the boreholes, was updated by including geophysical survey data in a co-kriging approach. The method applied to a real tunnel project shows significant improvements in rock mass quality predictions after including geophysical survey data, leading to better decision-making for construction safety design.

  2. Drilling, construction, geophysical log data, and lithologic log for boreholes USGS 142 and USGS 142A, Idaho National Laboratory, Idaho (United States)

    Twining, Brian V.; Hodges, Mary K.V.; Schusler, Kyle; Mudge, Christopher


    Starting in 2014, the U.S. Geological Survey in cooperation with the U.S. Department of Energy, drilled and constructed boreholes USGS 142 and USGS 142A for stratigraphic framework analyses and long-term groundwater monitoring of the eastern Snake River Plain aquifer at the Idaho National Laboratory in southeast Idaho. Borehole USGS 142 initially was cored to collect rock and sediment core, then re-drilled to complete construction as a screened water-level monitoring well. Borehole USGS 142A was drilled and constructed as a monitoring well after construction problems with borehole USGS 142 prevented access to upper 100 feet (ft) of the aquifer. Boreholes USGS 142 and USGS 142A are separated by about 30 ft and have similar geology and hydrologic characteristics. Groundwater was first measured near 530 feet below land surface (ft BLS) at both borehole locations. Water levels measured through piezometers, separated by almost 1,200 ft, in borehole USGS 142 indicate upward hydraulic gradients at this location. Following construction and data collection, screened water-level access lines were placed in boreholes USGS 142 and USGS 142A to allow for recurring water level measurements.Borehole USGS 142 was cored continuously, starting at the first basalt contact (about 4.9 ft BLS) to a depth of 1,880 ft BLS. Excluding surface sediment, recovery of basalt, rhyolite, and sediment core at borehole USGS 142 was approximately 89 percent or 1,666 ft of total core recovered. Based on visual inspection of core and geophysical data, material examined from 4.9 to 1,880 ft BLS in borehole USGS 142 consists of approximately 45 basalt flows, 16 significant sediment and (or) sedimentary rock layers, and rhyolite welded tuff. Rhyolite was encountered at approximately 1,396 ft BLS. Sediment layers comprise a large percentage of the borehole between 739 and 1,396 ft BLS with grain sizes ranging from clay and silt to cobble size. Sedimentary rock layers had calcite cement. Basalt flows

  3. Observations of mechanical-hydraulic-geochemical interactions due to drainage of a surface water reservoir in Switzerland (United States)

    Lunn, R. J.; Kinali, M.; Pytharouli, S.; Shipton, Z.; Stillings, M.; Lord, R.


    The drainage and refilling of a surface water reservoir beside the Grimsel Test Site (GTS) underground rock laboratory in Switzerland, has provided a unique opportunity to study in-situ rock mechanical, hydraulic and chemical interactions under large-scale stress changes. The reservoir was drained in October/November 2014 to enable dam maintenance and extension of the regional hydropower tunnel system. Reservoir drainage will have caused rapid unloading of the surrounding rock mass. The GTS sits 37m below the top of the reservoir and 200-600m away laterally within the mountainside on the eastern bank of the reservoir. Gradual refilling of the reservoir, via natural snowmelt and runoff, commenced in February 2015. As part of the European LASMO Project, researchers at Strathclyde, funded by Radioactive Waste Management Ltd., have been investigating mechanical-chemical-hydraulic coupling within the rock mass as an analogue for glacial unloading and loading of a future Geological Disposal Facility. We have deployed three 3-component and 6 single-component micro-seismometers within the GTS and surrounding hydropower tunnel network. In parallel, we have implemented a groundwater sampling programme, using boreholes within the GTS, for temporal determination of geochemistry and flow rate. Preliminary data analyses show geochemical anomalies during unloading, as well as detection of microseismic events. The signal-to-noise ratio of the micro-seismic data is extremely poor. Noise amplitude, and frequency content, variy throughout each day, between days, and from month-to-month on a highly unpredictable basis. This is probably due to the multitude of hydropower turbines and pump-storage systems within the surrounding mountains. To discriminate micro-seismic events, we have developed a new methodology for characterizing background noise within the seismic signal and combined this with cross-correlations techniques generally applied in microseismic analysis of hydraulic

  4. Site Characterization Data from the U3ax/bl Exploratory Boreholes at the Nevada Test Site

    Energy Technology Data Exchange (ETDEWEB)

    Bechtel Nevada; U.S. Department of Energy, National Nuclear Security Administration Nevada Site Office


    This report provides qualitative analyses and preliminary interpretations of hydrogeologic data obtained from two 45-degree, slanted exploratory boreholes drilled within the Area 3 Radioactive Waste Management Site (RWMS) at the Nevada Test Site. Borehole UE-3bl-D1 was drilled beneath the U3ax/bl mixed waste disposal unit, and Borehole UE-3bl-U1 was drilled in undisturbed alluvium adjacent to the disposal unit. The U3ax/bl disposal unit is located within two conjoined subsidence craters, U3ax and U3bl, which were created by underground nuclear testing. Data from these boreholes were collected to support site characterization activities for the U3ax/bl disposal unit and the entire Area 3 RWMS. Site characterization at disposal units within the Area 3 RWMS must address the possibility that subsidence craters and associated disturbed alluvium of the chimneys beneath the craters might serve as pathways for contaminant migration. The two boreholes were drilled and sampled to compare hydrogeologic properties of alluvium below the waste disposal unit with those of adjacent undisturbed alluvium. Whether Borehole UE-3bl-D1 actually penetrated the chimney of the U3bl crater is uncertain. Analyses of core samples showed little difference in hydrogeologic properties between the two boreholes. Important findings of this study include the following: No hazardous or radioactive constituents of waste disposal concern were found in the samples obtained from either borehole. No significant differences in physical and hydrogeologic properties between boreholes is evident, and no evidence of significant trends with depth for any of these properties was observed. The values observed are typical of sandy materials. The alluvium is dry, with volumetric water content ranging from 5.6 to 16.2 percent. Both boreholes exhibit a slight increase in water content with depth, the only such trend observed. Water potential measurements on core samples from both boreholes show a large positive

  5. Vertical seismic prospecting system using super elastic alloy

    Energy Technology Data Exchange (ETDEWEB)

    Inaba, T.; Horiba, N. [Nishimatsu Construction Co., Ltd., Kanagawa (Japan); Yamauchi, K. [Tokin Corp., Sendai (Japan); Hirata, A. [Kumamoto Inst. of Tech., Ikeda (Japan); Kaneko, K. [Hokkaido Univ., Sapporo (Japan)


    For tunneling, it is very important to understand the characteristic of the rock around the tunnel. A new method of rock property investigation by using a compact vertical seismic prospecting system is proposed. This system consists of a probe attached vibration sensor, computer and trigger system. A superelastic alloy plate is used to press the probe flexibly against borehole surface. (orig.)

  6. Monitoring the Groningen gas field by seismic noise interferometry

    NARCIS (Netherlands)

    Zhou, W.|info:eu-repo/dai/nl/187447268; Paulssen, H.|info:eu-repo/dai/nl/073584436


    The Groningen gas field in the Netherlands is the world’s 7th largest onshore gas field and has been producing from 1963. Since 2013, the year with the highest level of induced seismicity, the reservoir has been monitored by two geophone strings at reservoir level at about 3 km depth. For borehole

  7. Fault activation by hydraulic fracturing in western Canada. (United States)

    Bao, Xuewei; Eaton, David W


    Hydraulic fracturing has been inferred to trigger the majority of injection-induced earthquakes in western Canada, in contrast to the Midwestern United States, where massive saltwater disposal is the dominant triggering mechanism. A template-based earthquake catalog from a seismically active Canadian shale play, combined with comprehensive injection data during a 4-month interval, shows that earthquakes are tightly clustered in space and time near hydraulic fracturing sites. The largest event [moment magnitude (MW) 3.9] occurred several weeks after injection along a fault that appears to extend from the injection zone into crystalline basement. Patterns of seismicity indicate that stress changes during operations can activate fault slip to an offset distance of >1 km, whereas pressurization by hydraulic fracturing into a fault yields episodic seismicity that can persist for months. Copyright © 2016, American Association for the Advancement of Science.

  8. Borehole pressure and temperature measurement system

    Energy Technology Data Exchange (ETDEWEB)

    Perales, K.L.


    This patent describes apparatus for continuously measuring fluctuating pressure and temperature of a downhole fluid in a borehole at a desired depth. It comprises a tube positioned within the borehole; a housing suspended in the borehole at the desired depth from the tube; a pressurized test fluid source at the surface for initially pressuring the flow path in the tube and a portion of the chamber in the housing; a valve for selectively isolating fluid communications between the tube and the pressurized test fluid source; a thermocouple line including two dissimilar metal conductors; a manifold at the surface for sealing the selected fluid within the flow path; a pressure measuring device at the surface and in fluid communication; and a temperature measuring device at the surface for receiving the thermocouple line.

  9. Ultrasonic Modeling for Borehole Studies (United States)

    Perton, M.; Sanchez-Sesma, F. J.; Spurlin, J. H.; Flores, E.; Navarrete-Montesinos, M.; Gomez, R.


    Elastic wave propagation in and around wells is of interest in a variety of instances. It is relevant in petroleum and geothermal studies as the seismic signals in carefully designed experiments can be useful to characterize the reservoir rocks and design optimal operation. Numerical modeling of field data is usually the chosen strategy. However, the complexity of realistic settings sometimes is beyond analytical techniques and experiments may be helpful to visualize wave propagation. In this work both experiments and numerical simulations are presented to explore the possibilities of using ultrasonic scaled models. A laser ultrasonic experimental setup is used to study wave propagation around scaled wells. Two simulation techniques, the discrete wave number method and a finite differences, are used to understand the physics, to compute comparisons with the experimental signals, and to explore the advantages of scaled model. The main difference with the real scale is the mechanism of attenuation. Two simple and well-known attenuation models are used at the ultrasonic scale: the Kelvin-Voigt model for the solid and the Maxwell one into the fluid. Both are part of the Zener model usually used in the petroleum industry. According to the results quality, the model matches perfectly with the experience. Scaled models seem to be a new useful way to study elastic wave propagation in complex media. Acknowledgements. Partial support from DGAPA-UNAM, Project IN114706, Mexico is greatly appreciated.

  10. Preliminary Obtained Data from Borehole Geodetic Measurements in Marmara Region, Turkey (United States)

    Ozener, H.; Aktug, B.; Karabulut, H.; Ergintav, S.; Dogru, A.; Yilmaz, O.; Turgut, B.; Ahiska, B.; Mencin, D.; Mattioli, G. S.


    Dense continuous GPS networks quantify the time-dependent deformation field of the earthquake cycle. However the strainmeters can capture signals with superior precision at local spatial scales, in particular in the short-period, from minutes to a month. Many relatively small-scale events (e.i. SSEs, creeps) have been successfully determined on the subduction zones. Istanbul located near the most active parts of the North Anatolian Fault (NAF) has been monitored by different observing techniques such as seismic networks and continuous/survey-mode GPS networks for decades. However, it is still essential to observe deformation in a broad range of temporal and spatial scales (from seismology to geodesy and to geology). Borehole strainmeters are very sensitive to deformation in the range of less than a month. In this study, we present a new project, financially and technically supported by Istanbul Development Agency (ISTKA) and UNAVCO, respectively, which includes the installation of two borehole strainmeters are being deployed in European side of Istanbul in Marmara Region. Since these instruments can also respond to non-tectonic processes, it is necessary to have more instruments to increase spatial coherence and to have additional sensors to detect and model noise (such as barometric pressure, tides, or precipitation). The introduced monitoring system will provide significant insight about the creeping phenomenon and the possible SSE to our understanding of seismic hazards in active zones and possible precursors. Our long term objective is to build a borehole monitoring system in the region. By integrating various data obtained from borehole observations, we expect to get a better understanding of dynamics in the western NAF. In this presentation, we introduce data and ongoing analysis obtained with strainmeters.

  11. Emulsion for hydraulically breaking the gas layer

    Energy Technology Data Exchange (ETDEWEB)

    Matveev, D.F.; Kendis, M.Sh.; Polkovnichenko, I.T.; Yaroshenko, N.A.; Zhadanova, K.M.


    Acid monoesters and diesters of alkyl phosphates based on primary fatty alcohols of the C /sub 12/ -C /sub 16/ fraction are added as emulsifiers to an emulsion for hydraulically breaking the gas layer with a view to increasing its thermal stability. The components have the following ratio: hydrocarbon mixture, 9.8-20.6%; acid monoesters and diesters, 0.3-0.6%; aqueous fraction, 25.7-38.8%, and sand, 40-60%. In preparing the composition, the emulsifier is dissolved in a hydrocarbon liquid at 50/sup 0/C. Then, an aqueous phase is gradually added while stirring at a rate of 8,000-10,000 revolutions per minute for 30 min. Afterwards, sand is added. Tests of the mixtures for hydraulic breakage have been carried out in the laboratory by the KTs-5 consistometer. The plastic viscosity of the emulsions were determined in the absence of sand by the Reotest-2 device. The mixture which is proposed has heightened (up to 130/sup 0/C) thermal stability as compared with the known one (diesel fuel, water, ethanolamide of free fatty acids): the emulsions in a mixture with sand decompose at 70/sup 0/C. The high thermal stability of the mixture makes it possible to use hydraulic breakage in a wider range. The gas yield of the borehole doubles as a result of hydraulically breaking the productive layer by the given mixture.

  12. Characterization of Carbonate Hydrostratigraphy Using Ambient Seismic Noise: A Pilot Study in the Floridan Aquifer System, Ocala, FL, USA (United States)

    James, S.; Screaton, E.; Russo, R. M.; Panning, M. P.; Bremner, P. M.; Stanciu, A. C.; Torpey, M. E.; Hongsresawat, S.; Farrell, M. E.


    Defining zones of high and low hydraulic conductivity within aquifers is vital to hydrogeologic research and groundwater management. Carbonate aquifers are particularly difficult to characterize due to dissolution and dolomitization. We investigated a new imaging technique for aquifer characterization that uses cross-correlation of ambient seismic noise to determine seismic velocity structure. Differences in densities between confining units and high permeability flow zones can produce distinct seismic velocities in the correlated signals. We deployed an array of 9 short period geophones from 11/2013 to 3/2014 in Indian Lake State Forest, Florida, to determine if the high frequency diffusive seismic wavefield can be used for imaging hydrostratigraphy. Here, a thin surficial layer of siliciclastic deposits overlie a ~ 0.6 km sequence of Cenozoic limestone and dolomite units that comprise the Floridan Aquifer System (FAS). A low permeability dolomite unit vertically divides the FAS throughout most of Florida. Deep boreholes surrounding the site constrain hydrostratigraphy, however the horizontal continuity of the middle dolomite unit as well as its effectiveness as a confining unit in the study area are not well known. The stations were spaced at distances ranging from 0.18 to 2.6 km, and yielded 72 cross-correlation Green's functions for Rayleigh wave propagation at frequencies between 0.2 and 40 Hz, with dominant peaks around 0.8 Hz, 3 Hz and 13 Hz. Local vehicle traffic did interfere to a degree with the correlation of the diffuse waves, but was minimized by using only nighttime data. At the lowest frequencies (greatest depths) investigated, velocities increase with depth; however, correlations become less coherent at higher frequencies, perhaps due to shallow complex scattering. Comparison of cross-correlations for all station pairs also indicates spatial variations in velocity. Thus, the method shows promise for characterization of the heterogeneity of the

  13. Hydraulic Fracturing and the Environment (United States)

    Ayatollahy Tafti, T.; Aminzadeh, F.; Jafarpour, B.; de Barros, F.


    In this presentation, we highlight two key environmental concerns of hydraulic fracturing (HF), namely induced seismicity and groundwater contamination (GC). We examine the induced seismicity (IS) associated with different subsurface fluid injection and production (SFIP) operations and the key operational parameters of SFIP impacting it. In addition we review the key potential sources for possible water contamination. Both in the case of IS and GC we propose modeling and data analysis methods to quantify the risk factors to be used for monitoring and risk reduction. SFIP include presents a risk in hydraulic fracturing, waste water injection, enhanced oil recovery as well as geothermal energy operations. Although a recent report (NRC 2012) documents that HF is not responsible for most of the induced seismicities, we primarily focus on HF here. We look into vaious operational parameters such as volume and rate of water injection, the direction of the well versus the natural fracture network, the depth of the target and the local stress field and fault system, as well as other geological features. The latter would determine the potential for triggering tectonic related events by small induced seismicity events. We provide the building blocks for IS risk assessment and monitoring. The system we propose will involve adequate layers of complexity based on mapped seismic attributes as well as results from ANN and probabilistic predictive modeling workflows. This leads to a set of guidelines which further defines 'safe operating conditions' and 'safe operating zones' which will be a valuable reference for future SFIP operations. We also illustrate how HF can lead to groundwater aquifer contamination. The source of aquifer contamination can be the hydrocarbon gas or the chemicals used in the injected liquid in the formation. We explore possible pathways of contamination within and discuss the likelihood of contamination from each source. Many of the chemical compounds used

  14. Numerical modelling of CO2 migration in saline reservoirs using geoelectric and seismic techniques - first results (United States)

    Hagrey, S. A. Al; Strahser, M. H. P.; Rabbel, W.


    The research project "CO2 MoPa" (modelling and parameterisation of CO2 storage in deep saline formations for dimensions and risk analysis) has been initiated in 2008 by partners from different disciplines (e.g. geology, hydrogeology, geochemistry, geophysics, geomechanics, hydraulic engineering and law). It deals with the parameterisation of virtual subsurface storage sites to characterise rock properties, with high pressure-temperature experiments to determine in situ hydro-petrophysical and mechanical parameters, and with modelling of processes related to CCS in deep saline reservoirs. One objective is the estimation of the sensitivity and the resolution of reflection seismic and geoelectrical time-lapse measurements in order to determine the underground distribution of CO2. Compared with seismic, electric resistivity tomography (ERT) has lower resolution, but its permanent installation and continuous monitoring can make it an economical alternative or complement. Seismic and ERT (in boreholes) applications to quantify changes of intrinsic aquifers properties with time are justified by the velocity and resistivity decrease related to CO2 injection. Our numerical 2D/3D modelling reveals the capability of the techniques to map CO2 plumes and changes as a function of thickness, concentration, receiver/electrode configuration, aspect ratio and modelling and inversion constraint parameters. Depending on these factors, some configurations are favoured due to their better spatial resolution and lower artefacts. Acknowledgements This work has been carried out in the framework of "CO2 MoPa" research project funded by the Federal German Ministry of Education and Research (BMBF) and a consortium of energy companies (E.ON Energy, EnBW AG, RWE Dea AG, Stadtwerke Kiel AG, Vattenfall Europe Technology Research GmbH and Wintershall Holding AG).

  15. Simple, Affordable and Sustainable Borehole Observatories for Complex Monitoring Objectives (United States)

    Kopf, A.; Hammerschmidt, S.; Davis, E.; Saffer, D.; Wheat, G.; LaBonte, A.; Meldrum, R.; Heesemann, M.; Villinger, H.; Freudenthal, T.; Ratmeyer, V.; Renken, J.; Bergenthal, M.; Wefer, G.


    prism during IODP Exp. 319 and successfully recovered during IODP Exp. 332, both cruises being part of NanTroSEIZE (Nankai Trough Seismogenic Zone Experiment). The 15-months long data showed transients related to the arrival of seismic waves, storms and can further be used for detection of seismogenic strain events. Moreover, based on tidal signals in the pressure data, it was possible to make assumptions regarding the elastic properties of the surrounding formation. The SmartPlug was exchanged by an enhanced version, the GeniusPlug, which provides additional fluid sampling devices and microbiological experiments during the monitoring period. Its recovery is planned for 2013. Going one step further in simplicity, a Mini-CORK has recently developed especially designed for the portable seafloor drill rig MeBo (MARUM, Univ. Bremen, Germany), which can be installed without a drillship and which, due to its telemetric unit, makes costly recovery operations obsolete. The MeBo can be operated from any re-search vessel and allows coring to a depth of 70 m, which may be followed by instrumentation of the borehole with the MeBo-CORK. Two designs are available: the first design allows in situ measurement of pressure and temperature solely, whereas the second design consists of a seafloor unit including additional mission specific sensors (osmo-samlers for geochemistry and microbiology, etc.). A first field test for the MeBo-CORKs into mud volcanoes in the Kumano forearc basin is envisaged for summer 2012 to complement IODP project NanTroSEIZE.

  16. Borehole radar and BIPS investigations in boreholes at the Boda area

    Energy Technology Data Exchange (ETDEWEB)

    Carlsten, S.; Straahle, A. [GEOSIGMA AB, Uppsala (Sweden)


    As part of the studies conducted in the Boda area, measurements with borehole radar, borehole TV (BIPS) and deviation measurements were performed during May 2000. The investigations were carried out in four percussion-drilled boreholes with a total length of 514 m. Two boreholes are vertical and two are directed into and below the cave area. The BIPS measurement showed the presence of 14 open fractures. Largest apparent aperture width of open fractures was 133 mm. In the lowest part in boreholes 2, 3, and 4, particles in suspension deteriorated the visibility. BIPS has revealed a dominating subhorizontal fracture set and another striking NW to N-S with a dip close to vertical. Possible but very uncertain is a third fracture set striking NE and dipping steeply towards S. The open and partly open fractures forms an average block size 11 m wide and 6 m high, while the length of the block is uncertain. Of 98 borehole radar reflectors interpreted to intersect within BIPS-mapped sections, 90 were possible to combine with BIPS-mapped structures, i.e. 92% of the radar reflectors. The fractured rock around Boda is a shallow feature, since borehole radar and BIPS measurements shows no evidence of increased fracturing or the presence of caves at larger depth in the Boda area. The result indicates that the formation of the superficial fracture system (with caves included) at Boda in all probability is connected to glacial action, such as banking.

  17. Addresing environmental challenges to shale gas and hydraulic fracturing

    Energy Technology Data Exchange (ETDEWEB)

    Vadillo Fernandez, L.; Rodriguez Gomez, V.; Fernadez Naranjo, F.J.


    This article reviews the main issues of unconventional gas extracted by hydraulic fracturing techniques. Topics such as technology, fracturing stages, flowback characterization and alternatives of disposal and reuse, water consumption, physicochemical features of the geological formations, development of the fractures performed by hydraulic fracturing, well flow decline, land use and occupation and induced seismicity are presented, as well as the scientific debate: the potential steps of methane gas and groundwater contamination. (Author)

  18. Multilevel groundwater monitoring of hydraulic head and temperature in the eastern Snake River Plain aquifer, Idaho National Laboratory, Idaho, 2007-08 (United States)

    Fisher, Jason C.; Twining, Brian V.


    During 2007 and 2008, the U.S. Geological Survey, in cooperation with the U.S. Department of Energy, collected quarterly depth-discrete measurements of fluid pressure and temperature in six boreholes located in the eastern Snake River Plain aquifer of Idaho. Each borehole was instrumented with a multilevel monitoring system consisting of a series of valved measurement ports, packer bladders, casing segments, and couplers. Hydraulic heads (head) and water temperatures in boreholes were monitored at 86 hydraulically-isolated depth intervals located 448.0 to 1,377.6 feet below land surface. The calculation of head is most sensitive to fluid pressure and the altitude of the pressure transducer at each port coupling; it is least sensitive to barometric pressure and water temperature. An analysis of errors associated with the head calculation determined the accuracy of an individual head measurement at +/- 2.3 feet. Many of the sources of measurement error are diminished when considering the differences between two closely-spaced readings of head; therefore, a +/- 0.1 foot measurement accuracy was assumed for vertical head differences (and gradients) calculated between adjacent monitoring zones. Vertical head and temperature profiles were unique to each borehole, and were characteristic of the heterogeneity and anisotropy of the eastern Snake River Plain aquifer. The vertical hydraulic gradients in each borehole remained relatively constant over time with minimum Pearson correlation coefficients between head profiles ranging from 0.72 at borehole USGS 103 to 1.00 at boreholes USGS 133 and MIDDLE 2051. Major inflections in the head profiles almost always coincided with low permeability sediment layers. The presence of a sediment layer, however, was insufficient for identifying the location of a major head change in a borehole. The vertical hydraulic gradients were defined for the major inflections in the head profiles and were as much as 2.2 feet per foot. Head gradients

  19. Shallow velocity model in the area of Pozzo Pitarrone, Mt. Etna, from single station, array methods and borehole data

    Directory of Open Access Journals (Sweden)

    Luciano Zuccarello


    Full Text Available Seismic noise recorded by a temporary array installed around Pozzo Pitarrone, NE flank of Mt. Etna, have been analysed with several techniques. Single station HVSR method and SPAC array method have been applied to stationary seismic noise to investigate the local shallow structure. The inversion of dispersion curves produced a shear wave velocity model of the area reliable down to depth of about 130 m. A comparison of such model with the stratigraphic information available for the investigated area shows a good qualitative agreement. Taking advantage of a borehole station installed at 130 m depth, we could estimate also the P-wave velocity by comparing the borehole recordings of local earthquakes with the same event recorded at surface. Further insight on the P-wave velocity in the upper 130 m layer comes from the surface reflected wave observable in some cases at the borehole station. From this analysis we obtained an average P-wave velocity of about 1.2 km/s, compatible with the shear wave velocity found from the analysis of seismic noise.

  20. Factors Affecting Seismic Velocity in Alluvium (United States)

    Huckins-Gang, H.; Mercadante, J.; Prothro, L.


    Yucca Flat at the Nevada National Security Site has been selected as the Source Physics Experiment (SPE) Dry Alluvium Geology Phase II site. The alluvium in this part of Yucca Flat is typical of desert basin fill, with discontinuous beds that are highly variable in clast size and provenance. Detailed understanding of the subsurface geology will be needed for interpretation of the SPE seismic data. A 3D seismic velocity model, created for Yucca Flat using interval seismic velocity data, shows variations in velocity within alluvium near the SPE Phase II site beyond the usual gradual increase of density with depth due to compaction. In this study we examined borehole lithologic logs, geophysical logs, downhole videos, and laboratory analyses of sidewall core samples to understand which characteristics of the alluvium are related to these variations in seismic velocity. Seismic velocity of alluvium is generally related to its density, which can be affected by sediment provenance, clast size, gravel percentage, and matrix properties, in addition to compaction. This study presents a preliminary subdivision of the alluvial strata in the SPE Phase II area into mappable units expected to be significant to seismic modeling. Further refinements of the alluvial units may be possible when seismic data are obtained from SPE Phase II tests. This work was done by National Security Technologies, LLC, under Contract No. DE-AC52-06NA25946 with the U.S. Department of Energy.

  1. Borehole radar modeling for reservoir monitoring applications

    NARCIS (Netherlands)

    Miorali, M.; Slob, E.C.; Arts, R.J.


    The use of down-hole sensors and remotely controlled valves in wells provide enormous benefits to reservoir management and oil production. We suggest borehole radar measurements as a promising technique capable of monitoring the arrival of undesired fluids in the proximity of production wells. The

  2. Hydraulic conductivity of a firn aquifer system in southeast Greenland (United States)

    Miller, Olivia L.; Solomon, D. Kip; Miège, Clément; Koenig, Lora S.; Forster, Richard R.; Montgomery, Lynn N.; Schmerr, Nicholas; Ligtenberg, Stefan R. M.; Legchenko, Anatoly; Brucker, Ludovic


    Some regions of the Greenland ice sheet, where snow accumulation and melt rates are high, currently retain substantial volumes of liquid water within the firn pore space throughout the year. These firn aquifers, found between 10-30 m below the snow surface, may significantly affect sea level rise by storing or draining surface meltwater. The hydraulic gradient and the hydraulic conductivity control flow of meltwater through the firn. Here we describe the hydraulic conductivity of the firn aquifer estimated from slug tests and aquifer tests at six sites located upstream of Helheim Glacier in southeastern Greenland. We conducted slug tests using a novel instrument, a piezometer with a heated tip that melts itself into the ice sheet. Hydraulic conductivity ranges between 2.5x10-5 and 1.1x10-3 m/s. The geometric mean of hydraulic conductivity of the aquifer is 2.7x10-4 m/s with a geometric standard deviation of 1.4 from both depth specific slug tests (analyzed using the Hvorslev method) and aquifer tests during the recovery period. Hydraulic conductivity is relatively consistent between boreholes and only decreases slightly with depth. The hydraulic conductivity of the firn aquifer is crucial for determining flow rates and patterns within the aquifer, which inform hydrologic models of the aquifer, its relation to the broader glacial hydrologic system, and its effect on sea level rise.

  3. Hydraulic Conductivity of a Firn Aquifer in Southeast Greenland

    Directory of Open Access Journals (Sweden)

    Olivia L. Miller


    Full Text Available Some regions of the Greenland ice sheet, where snow accumulation and melt rates are high, currently retain substantial volumes of liquid water within the firn pore space throughout the year. These firn aquifers, found between ~10 and 30 m below the snow surface, may significantly affect sea level rise by storing or draining surface meltwater. The hydraulic gradient and the hydraulic conductivity control flow of meltwater through the firn. Here we describe the hydraulic conductivity of the firn aquifer estimated from slug tests and aquifer tests at six sites located upstream of Helheim Glacier in southeastern Greenland. We conducted slug tests using a novel instrument, a piezometer with a heated tip that melts itself into the ice sheet. Hydraulic conductivity ranges between 2.5 × 10−5 and 1.1 × 10−3 m/s. The geometric mean of hydraulic conductivity of the aquifer is 2.7 × 10−4 m/s with a geometric standard deviation of 1.4 from both depth specific slug tests (analyzed using the Hvorslev method and aquifer tests during the recovery period. Hydraulic conductivity is relatively consistent between boreholes and only decreases slightly with depth. The hydraulic conductivity of the firn aquifer is crucial for determining flow rates and patterns within the aquifer, which inform hydrologic models of the aquifer, its relation to the broader glacial hydrologic system, and its effect on sea level rise.

  4. Deep Borehole Field Test Research Activities at LBNL

    Energy Technology Data Exchange (ETDEWEB)

    Dobson, Patrick [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Tsang, Chin-Fu [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Kneafsey, Timothy [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Borglin, Sharon [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Piceno, Yvette [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Andersen, Gary [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nakagawa, Seiji [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Nihei, Kurt [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Rutqvist, Jonny [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Doughty, Christine [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Reagan, Matthew [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)


    The goal of the U.S. Department of Energy Used Fuel Disposition’s (UFD) Deep Borehole Field Test is to drill two 5 km large-diameter boreholes: a characterization borehole with a bottom-hole diameter of 8.5 inches and a field test borehole with a bottom-hole diameter of 17 inches. These boreholes will be used to demonstrate the ability to drill such holes in crystalline rocks, effectively characterize the bedrock repository system using geophysical, geochemical, and hydrological techniques, and emplace and retrieve test waste packages. These studies will be used to test the deep borehole disposal concept, which requires a hydrologically isolated environment characterized by low permeability, stable fluid density, reducing fluid chemistry conditions, and an effective borehole seal. During FY16, Lawrence Berkeley National Laboratory scientists conducted a number of research studies to support the UFD Deep Borehole Field Test effort. This work included providing supporting data for the Los Alamos National Laboratory geologic framework model for the proposed deep borehole site, conducting an analog study using an extensive suite of geoscience data and samples from a deep (2.5 km) research borehole in Sweden, conducting laboratory experiments and coupled process modeling related to borehole seals, and developing a suite of potential techniques that could be applied to the characterization and monitoring of the deep borehole environment. The results of these studies are presented in this report.

  5. comparison of performance of public and private boreholes

    African Journals Online (AJOL)


    comparison of the performance of three categories of boreholes namely: public operated boreholes owned by the Government ... The corresponding figures for the boreholes owned by individuals but operated for commercial use and the private owned and .... drilling companies, State Water Board,. Maintenance Companies ...

  6. Hydraulic Hybrid Vehicles (United States)

    EPA and the United Parcel Service (UPS) have developed a hydraulic hybrid delivery vehicle to explore and demonstrate the environmental benefits of the hydraulic hybrid for urban pick-up and delivery fleets.

  7. The Subglacial Access and Fast Ice Research Experiment (SAFIRE): 1. Borehole-based englacial and subglacial measurements from a rapidly-moving tidewater glacier: Store Glacier, Greenland (United States)

    Hubbard, Bryn; Doyle, Samuel; Christoffersen, Poul; Young, Tun Jan; Hofstede, Coen; Hubbard, Alun; Box, Jason; Todd, Joe; Bougamont, Marion


    As part of the Subglacial Access and Fast Ice Research Experiment (SAFIRE) pressurised hot water was used to drill four 603-616 m-long boreholes to the bed of the Greenland Ice Sheet at a site located 30 km from the calving front of fast-flowing, marine-terminating Store Glacier (70 degrees N, ~1000 m elevation). Four wired sensor strings were successfully installed in three of the boreholes. These included a thermistor string to obtain the englacial temperature profile installed in the same borehole as a string of tilt sensors to measure borehole deformation, and two sets of combined water pressure, electrical conductivity and turbidity sensors installed just above the bed in separate, adjacent boreholes. The boreholes made a strong hydrological connection to the bed during drilling, draining rapidly to ~80 m below the ice surface. The connection of subsequent boreholes was observed as a perturbation in water pressure and temperature recorded in neighbouring boreholes, indicating an effective hydrological connection between them. The sensors, which were wired to data-loggers at the surface, operated for between ~30 and >80 days from late summer into autumn before the cables stretched and snapped, with the lowermost sensors failing first. The records obtained from these sensors reveal (i) subglacial water pressures that were close to overburden but which generally increased through the period of measurement and varied diurnally by ~0.3 m, (ii) a minimum englacial temperature of -21 degrees C underlain by a zone of temperate ice, some tens of m thick, located immediately above the bed, and (iii) high rates of internal deformation and strain that increased towards the bed. These borehole observations are complemented by GPS measurements of ice motion, meteorological data, and seismic and radar surveys.

  8. Visualization of volumetric seismic data (United States)

    Spickermann, Dela; Böttinger, Michael; Ashfaq Ahmed, Khawar; Gajewski, Dirk


    Mostly driven by demands of high quality subsurface imaging, highly specialized tools and methods have been developed to support the processing, visualization and interpretation of seismic data. 3D seismic data acquisition and 4D time-lapse seismic monitoring are well-established techniques in academia and industry, producing large amounts of data to be processed, visualized and interpreted. In this context, interactive 3D visualization methods proved to be valuable for the analysis of 3D seismic data cubes - especially for sedimentary environments with continuous horizons. In crystalline and hard rock environments, where hydraulic stimulation techniques may be applied to produce geothermal energy, interpretation of the seismic data is a more challenging problem. Instead of continuous reflection horizons, the imaging targets are often steep dipping faults, causing a lot of diffractions. Without further preprocessing these geological structures are often hidden behind the noise in the data. In this PICO presentation we will present a workflow consisting of data processing steps, which enhance the signal-to-noise ratio, followed by a visualization step based on the use the commercially available general purpose 3D visualization system Avizo. Specifically, we have used Avizo Earth, an extension to Avizo, which supports the import of seismic data in SEG-Y format and offers easy access to state-of-the-art 3D visualization methods at interactive frame rates, even for large seismic data cubes. In seismic interpretation using visualization, interactivity is a key requirement for understanding complex 3D structures. In order to enable an easy communication of the insights gained during the interactive visualization process, animations of the visualized data were created which support the spatial understanding of the data.

  9. Seismic Prediction While Drilling (SPWD): Seismic exploration ahead of the drill bit using phased array sources (United States)

    Jaksch, Katrin; Giese, Rüdiger; Kopf, Matthias


    In the case of drilling for deep reservoirs previous exploration is indispensable. In recent years the focus shifted more on geological structures like small layers or hydrothermal fault systems. Beside 2D- or 3D-seismics from the surface and seismic measurements like Vertical Seismic Profile (VSP) or Seismic While Drilling (SWD) within a borehole these methods cannot always resolute this structures. The resolution is worsen the deeper and smaller the sought-after structures are. So, potential horizons like small layers in oil exploration or fault zones usable for geothermal energy production could be failed or not identified while drilling. The application of a device to explore the geology with a high resolution ahead of the drill bit in direction of drilling would be of high importance. Such a device would allow adjusting the drilling path according to the real geology and would minimize the risk of discovery and hence the costs for drilling. Within the project SPWD a device for seismic exploration ahead of the drill bit will be developed. This device should allow the seismic exploration to predict areas about 50 to 100 meters ahead of the drill bit with a resolution of one meter. At the GFZ a first prototype consisting of different units for seismic sources, receivers and data loggers has been designed and manufactured. As seismic sources four standard magnetostrictive actuators and as receivers four 3-component-geophones are used. Every unit, actuator or geophone, can be rotated in steps of 15° around the longitudinal axis of the prototype to test different measurement configurations. The SPWD prototype emits signal frequencies of about 500 up to 5000 Hz which are significant higher than in VSP and SWD. An increased radiation of seismic wave energy in the direction of the borehole axis allows the view in areas to be drilled. Therefore, every actuator must be controlled independently of each other regarding to amplitude and phase of the source signal to

  10. Electrical resistance tomography from measurements inside a steel cased borehole (United States)

    Daily, William D.; Schenkel, Clifford; Ramirez, Abelardo L.


    Electrical resistance tomography (ERT) produced from measurements taken inside a steel cased borehole. A tomographic inversion of electrical resistance measurements made within a steel casing was then made for the purpose of imaging the electrical resistivity distribution in the formation remotely from the borehole. The ERT method involves combining electrical resistance measurements made inside a steel casing of a borehole to determine the electrical resistivity in the formation adjacent to the borehole; and the inversion of electrical resistance measurements made from a borehole not cased with an electrically conducting casing to determine the electrical resistivity distribution remotely from a borehole. It has been demonstrated that by using these combined techniques, highly accurate current injection and voltage measurements, made at appropriate points within the casing, can be tomographically inverted to yield useful information outside the borehole casing.


    Ning, F.; Wu, N.; Jiang, G.; Zhang, L.


    bohole. If the formation has a low permeability and is heated quickly, the dissociated gas and water couldn’t flow away in time, which is likely to bring a hazard of excess pore pressure. Especially in the area near the wall of borehole, the increase degree of pore pressure is high than other area because the dissociation of gas hydrates is relatively violent and hydraulic gradient is bigger. We also studied the distribution of water saturation around borehole after 10min, 30min and 60min respectively. It revealed that along with the invasion of drilling fluid and dissociation of gas hydrate, the degree of water saturation increased gradually. The effect of gas hydrate dissociation and drilling fluids invasion on borehole stability is to weaken mechanical properties of wellbore and change the pore pressure, then changes the effective stress of gas hydrates-bearing sediment. So temperature, pressure in the borehole and filter loss of drilling fluids should be controlled strictly to prevent gas hydrates from decomposing largely and in order to keep the borehole stability in the gas hydrates-bearing formations.

  12. Seismic Creep (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden erupture associated with an earthquake. It is a usually slow deformation...

  13. Seismic-Reliability-Based Optimal Layout of a Water Distribution Network


    Do Guen Yoo; Donghwi Jung; Doosun Kang; Joong Hoon Kim


    We proposed an economic, cost-constrained optimal design of a water distribution system (WDS) that maximizes seismic reliability while satisfying pressure constraints. The model quantifies the seismic reliability of a WDS through a series of procedures: stochastic earthquake generation, seismic intensity attenuation, determination of the pipe failure status (normal, leakage, and breakage), pipe failure modeling in hydraulic simulation, and negative pressure treatment. The network’s seismic re...

  14. Multicomponent ensemble models to forecast induced seismicity (United States)

    Király-Proag, E.; Gischig, V.; Zechar, J. D.; Wiemer, S.


    In recent years, human-induced seismicity has become a more and more relevant topic due to its economic and social implications. Several models and approaches have been developed to explain underlying physical processes or forecast induced seismicity. They range from simple statistical models to coupled numerical models incorporating complex physics. We advocate the need for forecast testing as currently the best method for ascertaining if models are capable to reasonably accounting for key physical governing processes—or not. Moreover, operational forecast models are of great interest to help on-site decision-making in projects entailing induced earthquakes. We previously introduced a standardized framework following the guidelines of the Collaboratory for the Study of Earthquake Predictability, the Induced Seismicity Test Bench, to test, validate, and rank induced seismicity models. In this study, we describe how to construct multicomponent ensemble models based on Bayesian weightings that deliver more accurate forecasts than individual models in the case of Basel 2006 and Soultz-sous-Forêts 2004 enhanced geothermal stimulation projects. For this, we examine five calibrated variants of two significantly different model groups: (1) Shapiro and Smoothed Seismicity based on the seismogenic index, simple modified Omori-law-type seismicity decay, and temporally weighted smoothed seismicity; (2) Hydraulics and Seismicity based on numerically modelled pore pressure evolution that triggers seismicity using the Mohr-Coulomb failure criterion. We also demonstrate how the individual and ensemble models would perform as part of an operational Adaptive Traffic Light System. Investigating seismicity forecasts based on a range of potential injection scenarios, we use forecast periods of different durations to compute the occurrence probabilities of seismic events M ≥ 3. We show that in the case of the Basel 2006 geothermal stimulation the models forecast hazardous levels

  15. Deep Borehole Field Test Conceptual Design Report

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest L. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This report documents conceptual design development for the Deep Borehole Field Test (DBFT), including test packages (simulated waste packages, not containing waste) and a system for demonstrating emplacement and retrieval of those packages in the planned Field Test Borehole (FTB). For the DBFT to have demonstration value, it must be based on conceptualization of a deep borehole disposal (DBD) system. This document therefore identifies key options for a DBD system, describes an updated reference DBD concept, and derives a recommended concept for the DBFT demonstration. The objective of the DBFT is to confirm the safety and feasibility of the DBD concept for long-term isolation of radioactive waste. The conceptual design described in this report will demonstrate equipment and operations for safe waste handling and downhole emplacement of test packages, while contributing to an evaluation of the overall safety and practicality of the DBD concept. The DBFT also includes drilling and downhole characterization investigations that are described elsewhere (see Section 1). Importantly, no radioactive waste will be used in the DBFT, nor will the DBFT site be used for disposal of any type of waste. The foremost performance objective for conduct of the DBFT is to demonstrate safe operations in all aspects of the test.

  16. Broad Band Data and Noise Observed with Surface Station and Borehole Station (United States)

    Tunc, Suleyman; Ozel, Oguz; Safa Arslan, Mehmet; Behiye Akşahin, Bengi; Hatipoglu, Mustafa; Cagin Yalcintepe, Ragip; Ada, Samim; Meral Ozel, Nurcan


    Marmara region tectonically is very active and many destructive earthquakes happened in the past. North Anatolian Fault Zone crosses the Marmara region and it has three branches. The northern branch passes through Marmara Sea and expected future large earthquake will happen along this fault zone. There is a gap in seismic network in the Marmara region at offshore and onshore areas. We have started broadband borehole seismographic observations to obtain the detailed information about fault geometry and its stick-slip behavior beneath the western Marmara Sea, as a part of the MARsite collaborative Project, namely "New Directions in Seismic Hazard Assessment through Focused Earth Observation in the Marmara Supersite-MARsite". The target area western Marmara of Turkey. In the beginning of the project, we installed eight Broadband surface station around Marmara Sea in April 2014. Then, we added broadband sensor and broadband surface sensor at the same location in November 2014. In this study, we developed a Matlab application to calculate Power Spectral Density against the New Low Noise Model (NLNM) and New High Noise Model (NHNM) determined for one-hour segments of the data. Also we compared ambient noise of broadband borehole sensor and surface broadband sensor.

  17. Analysis of the Thermal and Hydraulic Stimulation Program at Raft River, Idaho (United States)

    Bradford, Jacob; McLennan, John; Moore, Joseph; Podgorney, Robert; Plummer, Mitchell; Nash, Greg


    The Raft River geothermal field, located in southern Idaho, roughly 100 miles northwest of Salt Lake City, is the site of a Department of Energy Enhanced Geothermal System project designed to develop new techniques for enhancing the permeability of geothermal wells. RRG-9 ST1, the target stimulation well, was drilled to a measured depth of 5962 ft. and cased to 5551 ft. The open-hole section of the well penetrates Precambrian quartzite and quartz monzonite. The well encountered a temperature of 282 °F at its base. Thermal and hydraulic stimulation was initiated in June 2013. Several injection strategies have been employed. These strategies have included the continuous injection of water at temperatures ranging from 53 to 115 °F at wellhead pressures of approximately 275 psi and three short-term hydraulic stimulations at pressures up to approximately 1150 psi. Flow rates, wellhead and line pressures and fluid temperatures are measured continuously. These data are being utilized to assess the effectiveness of the stimulation program. As of August 2014, nearly 90 million gallons have been injected. A modified Hall plot has been used to characterize the relationships between the bottom-hole flowing pressure and the cumulative injection fluid volume. The data indicate that the skin factor is decreased, and/or the permeability around the wellbore has increased since the stimulation program was initiated. The injectivity index also indicates a positive improvement with values ranging from 0.15 gal/min psi in July 2013 to 1.73 gal/min psi in February 2015. Absolute flow rates have increased from approximately 20 to 475 gpm by February 2 2015. Geologic, downhole temperature and seismic data suggest the injected fluid enters a fracture zone at 5650 ft and then travels upward to a permeable horizon at the contact between the Precambrian rocks and the overlying Tertiary sedimentary and volcanic deposits. The reservoir simulation program FALCON developed at the Idaho National

  18. Techniques for determining subsurface stress direction and assessing hydraulic fracture azimuth

    Energy Technology Data Exchange (ETDEWEB)

    Hill, R.E.; Peterson, R.E.; Warpinski, N.R.; Lorenz, J.C.; Teufel, L.W. [Sandia National Labs., Albuquerque, NM (United States); Aslakson, J.K.


    This reference paper reviews and describes 15 techniques for determining hydraulic fracture azimuth. The techniques described are categorized into core-based, borehole-based, near-wellbore, and regional geologic indicators that can be used to predict or measure hydraulic fracture azimuth. The core based methods include: (1) circumferential velocity anisotropy, (2) anelastic strain recovery, (3) differential strain curve analysis, (4) axial point load tests, (5) petrographic examination of microcracks, (6) overcoming of archived core, (7) drilling-induced fractures in core, and (8) direct observation of over-cored open-hole stress test fractures. The borehole based techniques include: (9) borehole breakouts, (10) borehole deformation, (11) borehole imaging of drilling induced fractures, and (12) directional gamma ray logging. The near-wellbore techniques provided data on the orientation of the fracture induced during an actual fracture treatment and include: (13) microseismic logging and (14) earth tilt surveys. Finally there are the geologic indicators (Method 15) including earthquake focal mechanisms, fault slip data, surface mapping of neotectonic joints, and volcanic vent alignment. These regional data have been compiled for the World Stress Mapping Project and many maps are available that can be used as a first approximation of stress direction. Experience has shown that the more techniques that can be used in a single well or field, the more reliable the result. The concept or theoretical basis for each technique as well as the benefits and limitations of the techniques are described.

  19. Comparative Tests Between Shallow Downhole Installation and Classical Seismic Vaults (United States)

    Charade, Olivier; Vergne, Jérôme; Bonaimé, Sébastien; Bonnin, Mickaël; Louis-Xavier, Thierry; Beucler, Eric; Manhaval, Bertrand; Arnold, Benoît


    The French permanent broadband network is engaged in a major evolution with the installation of a hundred of new stations within the forthcoming years. Since most of them will be located in open field environments, we are looking for a standardized installation method able to provide good noise level performance at a reasonable cost. Nowadays, the use of posthole seismometers that can be deployed at the bottom of shallow boreholes appears to be an affordable and alternative solution to more traditional installation methods such as seismic vaults or dedicated underground cellars. Here we present some comparative tests performed at different sites (including two GEOSCOPE stations), spanning various geological conditions. On each site, posthole sensors were deployed for several weeks to months at various depths from 1.5m up to 20m. We compare the seismic noise levels measured in the different boreholes with the one for a reference sensor either directly buried or installed in a tunnel, a cellar or a seismic vault. Apart from the microseism frequency band, seismic noise level in most of the boreholes equals or outperforms the one obtained for the reference sensors. At periods higher than 20s we observe a strong reduction of the seismic noise on the horizontal components in the deepest boreholes compared to near surface installations. This improvement can reach up to 30dB and appears to be mostly due to a reduction in tilt noise induced by wind or local pressure variations. However, the absolute noise level that can be achieved strongly depends on the local geology.

  20. Causality between expansion of seismic cloud and maximum magnitude of induced seismicity in geothermal field (United States)

    Mukuhira, Yusuke; Asanuma, Hiroshi; Ito, Takatoshi; Häring, Markus


    Occurrence of induced seismicity with large magnitude is critical environmental issues associated with fluid injection for shale gas/oil extraction, waste water disposal, carbon capture and storage, and engineered geothermal systems (EGS). Studies for prediction of the hazardous seismicity and risk assessment of induced seismicity has been activated recently. Many of these studies are based on the seismological statistics and these models use the information of the occurrence time and event magnitude. We have originally developed physics based model named "possible seismic moment model" to evaluate seismic activity and assess seismic moment which can be ready to release. This model is totally based on microseismic information of occurrence time, hypocenter location and magnitude (seismic moment). This model assumes existence of representative parameter having physical meaning that release-able seismic moment per rock volume (seismic moment density) at given field. Seismic moment density is to be estimated from microseismic distribution and their seismic moment. In addition to this, stimulated rock volume is also inferred by progress of microseismic cloud at given time and this quantity can be interpreted as the rock volume which can release seismic energy due to weakening effect of normal stress by injected fluid. Product of these two parameters (equation (1)) provide possible seismic moment which can be released from current stimulated zone as a model output. Difference between output of this model and observed cumulative seismic moment corresponds the seismic moment which will be released in future, based on current stimulation conditions. This value can be translated into possible maximum magnitude of induced seismicity in future. As this way, possible seismic moment can be used to have feedback to hydraulic stimulation operation in real time as an index which can be interpreted easily and intuitively. Possible seismic moment is defined as equation (1), where D

  1. Laboratory hydraulic fracturing experiments in intact and pre-fractured rock (United States)

    Zoback, M.D.; Rummel, F.; Jung, R.; Raleigh, C.B.


    Laboratory hydraulic fracturing experiments were conducted to investigate two factors which could influence the use of the hydrofrac technique for in-situ stress determinations; the possible dependence of the breakdown pressure upon the rate of borehole pressurization, and the influence of pre-existing cracks on the orientation of generated fractures. The experiments have shown that while the rate of borehole pressurization has a marked effect on breakdown pressures, the pressure at which hydraulic fractures initiate (and thus tensile strength) is independent of the rate of borehole pressurization when the effect of fluid penetration is negligible. Thus, the experiments indicate that use of breakdown pressures rather than fracture initiation pressures may lead to an erroneous estimate of tectonic stresses. A conceptual model is proposed to explain anomalously high breakdown pressures observed when fracturing with high viscosity fluids. In this model, initial fracture propagation is presumed to be stable due to large differences between the borehole pressure and that within the fracture. In samples which contained pre-existing fractures which were 'leaky' to water, we found it possible to generate hydraulic fractures oriented parallel to the direction of maximum compression if high viscosity drilling mud was used as the fracturing fluid. ?? 1977.

  2. Seismic bearing (United States)

    Power, Dennis


    Textron Systems (Textron) has been using geophones for target detection for many years. This sensing capability was utilized for detection and classification purposes only. Recently Textron has been evaluating multiaxis geophones to calculate bearings and track targets more specifically personnel. This capability will not only aid the system in locating personnel in bearing space or cartesian space but also enhance detection and reduce false alarms. Textron has been involved in the testing and evaluation of several sensors at multiple sites. One of the challenges of calculating seismic bearing is an adequate signal to noise ratio. The sensor signal to noise ratio is a function of sensor coupling to the ground, seismic propagation and range to target. The goals of testing at multiple sites are to gain a good understanding of the maximum and minimum ranges for bearing and detection and to exploit that information to tailor sensor system emplacement to achieve desired performance. Test sites include 10A Site Devens, MA, McKenna Airfield Ft. Benning, GA and Yuma Proving Ground Yuma, AZ. Geophone sensors evaluated include a 28 Hz triax spike, a 15 Hz triax spike and a hybrid triax spike consisting of a 10 Hz vertical geophone and two 28 Hz horizontal geophones. The algorithm uses raw seismic data to calculate the bearings. All evaluated sensors have triaxial geophone configuration mounted to a spike housing/fixture. The suite of sensors also compares various types of geophones to evaluate benefits in lower bandwidth. The data products of these tests include raw geophone signals, seismic features, seismic bearings, seismic detection and GPS position truth data. The analyses produce Probability of Detection vs range, bearing accuracy vs range, and seismic feature level vs range. These analysis products are compared across test sites and sensor types.

  3. Interpretation of Borehole Geophysical Logs, Aquifer-Isolation Tests, and Water-Quality Data for Sites 1, 3, and 5 at the Willow Grove Naval Air Station/Joint Reserve Base, Horsham Township, Montgomery County, Pennsylvania: 2005 (United States)

    Sloto, Ronald A.


    Borehole geophysical logging, heatpulse-flowmeter measurements, borehole television surveys, and aquifer-isolation tests were conducted in 2005 at the Willow Grove Naval Air Station/Joint Reserve Base (NAS/JRB) in Horsham Township, Montgomery County, Pa. This study was done by the U.S. Geological Survey (USGS) in cooperation with the U.S. Navy in support of hydrogeological investigations to address ground-water contamination. Data collected for this study are valuable for understanding ground-water flow in the Stockton Formation at the local and regional scale. The Willow Grove NAS/JRB is underlain by the Stockton Formation, which consists of sedimentary rocks of Triassic age. The rocks of the Stockton Formation form a complex, heterogeneous aquifer with partially connected zones of high permeability. Borehole geophysical logs, heatpulse-flowmeter measurements, and borehole television surveys made in seven boreholes ranging from 70 to 350 ft deep were used to identify potential water-producing fractures and fracture zones and to select intervals for aquifer-isolation tests. An upward vertical hydraulic gradient was measured in one borehole, a downward vertical hydraulic gradient was measured in four boreholes, both an upward and a downward vertical hydraulic gradient were measured in one borehole, and no flow was measurable in one borehole. The aquifer-isolation tests isolated 30 discrete fractures in the seven boreholes for collection of depth-discrete hydraulic and water-quality data. Of the 30 fractures identified as potentially water producing, 26 fractures (87 percent) produced more than 1 gallon per minute of water. The specific capacity of the isolated intervals producing more than 1 gallon per minute ranged from 0.02 to 5.2 gallons per minute per foot. There was no relation between specific capacity and depth of the fracture. Samples for analysis for volatile organic compounds were collected from each isolated zone. Tetrachloroethylene (PCE) was the most

  4. Hydraulic Yaw System

    DEFF Research Database (Denmark)

    Stubkier, Søren; Pedersen, Henrik C.; Mørkholt, M.

    system and rotor shaft when utilizing the soft yaw drive concept compared to the original stiff yaw system. The physical demands of the hydraulic yaw system are furthermore examined for a life time of 20 years. Based on the extrapolated loads, the duty cycles show that it is possible to construct...... a hydraulic soft yaw system, which is able to reduce the loads on the wind turbine significantly. A full scale hydraulic yaw test rig is available for experiments and tests. The test rig is presented as well as the system schematics of the hydraulic yaw system....

  5. An integrated investigation of the induced seismicity near Crooked Lake, Alberta, Canada in 2016 (United States)

    Wang, R.; Gu, Y. J.; Shen, J.; Schultz, R.


    In the past three years, the Crooked Lake (or Fox Creek) region has become one of the most seismically active areas in the Western Canada Sedimentary Basin (WCSB), mostly attributable to hydraulic-fracturing operations on shale gas. Among the human-related earthquakes, the January 12, 2016 event (M = 4.1) not only triggered the "red light" provincial protocol, leading to the temporary suspension of a near-by injection well, but also set a new magnitude record for earthquakes in Alberta in the last decade. In this study, we determine the source parameters (e.g., magnitude, hypocenter location) of this earthquake and its aftershocks using full moment tensor inversions. Our findings are consistent with the anthropogenic origin of this earthquake and the source solution of the main shock shows a strike-slip mechanism with limited non-double-couple components ( 22%). The candidate fault orientations, which are predominantly N-S and E-W trending, are consistent with those of earlier events in this region but different from induced events in other parts in the WCSB. The inferred compressional axis is supported by crustal stress orientations extracted from bore-hole breakouts and the right-lateral fault is preferred by both seismic and aeromagnetic data. A further analysis of the waveforms from the near-source stations (area, possibly a reflection of fluid migration and/or changes in stress field. In short, our integrated study on the January 2016 earthquake cluster offers critical insights on the nature of induced earthquakes in the Crooked Lake region and other parts of the WCSB.

  6. Spatial distribution of reservoir properties using seismic attributes correlated to log properties

    Energy Technology Data Exchange (ETDEWEB)

    Dickerman, K.; Caamano, E. (Conoco Indonesia Inc., Jakarta (Malaysia)); Gir, R. (P.T. Schlumberger Geophysics Nusantara, Jakarta (Malaysia))


    Reservoir description maps have traditionally been generated using seismic data in succession with well log data. Integrating well logs with seismic maps in a separate step is not taking advantage of all the information contained within a 3-D data set. This paper describes a technique that statistically correlates seismic and log data to produce integrated maps of reservoir frequencies with increased resolution and confidence. The procedure involves first matching 3-D seismic with borehole seismic data. Then a statistical correlation is attempted between seismic attributes including amplitude, impedance, velocity, etc., and log properties such as porosity, water saturation, net to gross, bulk water volume, etc. at the well intersections. A multivariant function of the correlations is then derived. This function is applied to seismic data to produce reservoir property maps. This technique has been applied to 3-D data from Indonesia. Results and problems in estimating the functional relationship are discussed.

  7. Borehole Logging for Uranium by Gamma-Ray Spectrometry

    DEFF Research Database (Denmark)

    Løvborg, Leif; Nyegaard, P.; Christiansen, E. M.


    The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... to another; this variation is believed to be caused by emanation of radon (Rn) from the borehole walls. Block calculations based on individual calibration constants for the boreholes logged made it possible to obtain a reliable estimate of the tonnage of U. This estimate was only slightly different from...

  8. Seismic Studies

    Energy Technology Data Exchange (ETDEWEB)

    R. Quittmeyer


    This technical work plan (TWP) describes the efforts to develop and confirm seismic ground motion inputs used for preclosure design and probabilistic safety 'analyses and to assess the postclosure performance of a repository at Yucca Mountain, Nevada. As part of the effort to develop seismic inputs, the TWP covers testing and analyses that provide the technical basis for inputs to the seismic ground-motion site-response model. The TWP also addresses preparation of a seismic methodology report for submission to the U.S. Nuclear Regulatory Commission (NRC). The activities discussed in this TWP are planned for fiscal years (FY) 2006 through 2008. Some of the work enhances the technical basis for previously developed seismic inputs and reduces uncertainties and conservatism used in previous analyses and modeling. These activities support the defense of a license application. Other activities provide new results that will support development of the preclosure, safety case; these results directly support and will be included in the license application. Table 1 indicates which activities support the license application and which support licensing defense. The activities are listed in Section 1.2; the methods and approaches used to implement them are discussed in more detail in Section 2.2. Technical and performance objectives of this work scope are: (1) For annual ground motion exceedance probabilities appropriate for preclosure design analyses, provide site-specific seismic design acceleration response spectra for a range of damping values; strain-compatible soil properties; peak motions, strains, and curvatures as a function of depth; and time histories (acceleration, velocity, and displacement). Provide seismic design inputs for the waste emplacement level and for surface sites. Results should be consistent with the probabilistic seismic hazard analysis (PSHA) for Yucca Mountain and reflect, as appropriate, available knowledge on the limits to extreme ground

  9. Comparison between results of detailed tectonic studies on borehole core vs microresistivity images of borehole wall from gas-bearing shale complexes, Baltic Basin, Poland. (United States)

    Bobek, Kinga; Jarosiński, Marek; Pachytel, Radomir


    Structural analysis of borehole core and microresistivity images yield an information about geometry of natural fracture network and their potential importance for reservoir stimulation. Density of natural fractures and their orientation in respect to the maximum horizontal stress has crucial meaning for hydraulic fractures propagation in unconventional reservoirs. We have investigated several hundred meters of continuous borehole core and corresponding microresistivity images (mostly XRMI) from six boreholes in the Pomeranian part of the Early Paleozoic Baltic Basin. In general, our results challenge the question about representatives of statistics based on structural analyses on a small shale volume represented by borehole core or borehole wall images and credibility of different sets of data. Most frequently, fractures observed in both XRMI and cores are steep, small strata-bound fractures and veins with minor mechanical aperture (0,1 mm in average). These veins create an orthogonal joint system, locally disturbed by fractures associated with normal or by gently dipping thrust faults. Mean fractures' height keeps in a range between 30-50 cm. Fracture density differs significantly among boreholes and Consistent Lithological Units (CLUs) but the most frequent means falls in a range 2-4 m-1. We have also payed an attention to bedding planes due to their expected coupling with natural fractures and their role as structural barriers for vertical fracture propagation. We aimed in construction for each CLU the so-called "mean brick", which size is limited by an average distance between two principal joint sets and between bedding fractures. In our study we have found out a discrepancy between structural profiles based on XRMI and core interpretation. For some CLUs joint fractures densities, are higher in cores than in XRMI. In this case, numerous small fractures were not recorded due to the limits of XRMI resolution. However, the most veins with aperture 0,1 mm

  10. Microplasticity effect in low-velocity zone induced by seismic wave (United States)

    Mashinskii, E. I.


    Microplasticity effects in loam caused by seismic wave of frequency about 1000 Hz are detected in the borehole-to-borehole measurements. Microplasticity manifestations on seismic record are presented as the ladder-like stepwise changes in amplitude course. The step (plateau) on seismic trace is time delay, its duration depends on the strain-amplitude value. Time delay changes the frequency characteristic of stress pulse, nonlinearly transforms wave front, and shifts the amplitude maximum along time axis. The microplastic process occurs owing to the anomalous realignment of the internal stresses on the microstructural defects in the area of small deformations. This is the useful contribution to wave propagation physics. The received results can also be used in solving the applied problems in material science, seismic prospecting, diagnostics, etc.

  11. Thermally Actuated Hydraulic Pumps (United States)

    Jones, Jack; Ross, Ronald; Chao, Yi


    Thermally actuated hydraulic pumps have been proposed for diverse applications in which direct electrical or mechanical actuation is undesirable and the relative slowness of thermal actuation can be tolerated. The proposed pumps would not contain any sliding (wearing) parts in their compressors and, hence, could have long operational lifetimes. The basic principle of a pump according to the proposal is to utilize the thermal expansion and contraction of a wax or other phase-change material in contact with a hydraulic fluid in a rigid chamber. Heating the chamber and its contents from below to above the melting temperature of the phase-change material would cause the material to expand significantly, thus causing a substantial increase in hydraulic pressure and/or a substantial displacement of hydraulic fluid out of the chamber. Similarly, cooling the chamber and its contents from above to below the melting temperature of the phase-change material would cause the material to contract significantly, thus causing a substantial decrease in hydraulic pressure and/or a substantial displacement of hydraulic fluid into the chamber. The displacement of the hydraulic fluid could be used to drive a piston. The figure illustrates a simple example of a hydraulic jack driven by a thermally actuated hydraulic pump. The pump chamber would be a cylinder containing encapsulated wax pellets and containing radial fins to facilitate transfer of heat to and from the wax. The plastic encapsulation would serve as an oil/wax barrier and the remaining interior space could be filled with hydraulic oil. A filter would retain the encapsulated wax particles in the pump chamber while allowing the hydraulic oil to flow into and out of the chamber. In one important class of potential applications, thermally actuated hydraulic pumps, exploiting vertical ocean temperature gradients for heating and cooling as needed, would be used to vary hydraulic pressures to control buoyancy in undersea research

  12. Modeling and visualizing borehole information on virtual globes using KML (United States)

    Zhu, Liang-feng; Wang, Xi-feng; Zhang, Bing


    Advances in virtual globes and Keyhole Markup Language (KML) are providing the Earth scientists with the universal platforms to manage, visualize, integrate and disseminate geospatial information. In order to use KML to represent and disseminate subsurface geological information on virtual globes, we present an automatic method for modeling and visualizing a large volume of borehole information. Based on a standard form of borehole database, the method first creates a variety of borehole models with different levels of detail (LODs), including point placemarks representing drilling locations, scatter dots representing contacts and tube models representing strata. Subsequently, the level-of-detail based (LOD-based) multi-scale representation is constructed to enhance the efficiency of visualizing large numbers of boreholes. Finally, the modeling result can be loaded into a virtual globe application for 3D visualization. An implementation program, termed Borehole2KML, is developed to automatically convert borehole data into KML documents. A case study of using Borehole2KML to create borehole models in Shanghai shows that the modeling method is applicable to visualize, integrate and disseminate borehole information on the Internet. The method we have developed has potential use in societal service of geological information.

  13. Hydraulic Structures : Locks

    NARCIS (Netherlands)

    Molenaar, W.F.

    These lecture notes on locks are part of the study material belonging to the course 'Hydraulic Structures 1' (code CT3330), part of the Bachelor of Science and the Master of Science, the Hydraulic Engineering track, for civil engineering students at Delft University of Technology. Many of the

  14. Completion summary for boreholes USGS 140 and USGS 141 near the Advanced Test Reactor Complex, Idaho National Laboratory, Idaho (United States)

    Twining, Brian V.; Bartholomay, Roy C.; Hodges, Mary K.V.


    with gravel was described. Basalt flows generally ranged in thickness from 3 to 76 ft (average of 14 ft) and varied from highly fractured to dense with high to low vesiculation. Geophysical and borehole video logs were collected during certain stages of the drilling and construction process at boreholes USGS 140 and USGS 141. Geophysical logs were examined synergistically with the core material for borehole USGS 140; additionally, geophysical data were examined to confirm geologic and hydrologic similarities between boreholes USGS 140 and USGS 141 because core was not collected for borehole USGS 141. Geophysical data suggest the occurrence of fractured and (or) vesiculated basalt, dense basalt, and sediment layering in both the saturated and unsaturated zones in borehole USGS 141. Omni-directional density measurements were used to assess the completeness of the grout annular seal behind 6-in. diameter well casing. Furthermore, gyroscopic deviation measurements were used to measure horizontal and vertical displacement at all depths in boreholes USGS 140 and USGS 141. Single-well aquifer tests were done following construction at wells USGS 140 and USGS 141 and data examined after the tests were used to provide estimates of specific-capacity, transmissivity, and hydraulic conductivity. The specific capacity, transmissivity, and hydraulic conductivity for well USGS 140 were estimated at 2,370 gallons per minute per foot [(gal/min)/ft)], 4.06 × 105 feet squared per day (ft2/d), and 740 feet per day (ft/d), respectively. The specific capacity, transmissivity, and hydraulic conductivity for well USGS 141 were estimated at 470 (gal/min)/ft, 5.95 × 104 ft2/d, and 110 ft/d, respectively. Measured flow rates remained relatively constant in well USGS 140 with averages of 23.9 and 23.7 gal/min during the first and second aquifer tests, respectively, and in well USGS 141 with an average of 23.4 gal/min. Water samples were analyzed for cations, anions, metals, nutrients, volatile

  15. Analytical Data Report for Sediment Samples Collected From 116-KE-3 and UPR-100-K-1; Boreholes C8796 and C8796

    Energy Technology Data Exchange (ETDEWEB)

    Snyder, Michelle M.V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Stephenson, John R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)


    CH2M Hill Plateau Remediation Company (CHPRC) requested the services of the Pacific Northwest National Laboratory (PNNL) to perform contaminant leach testing on samples from two boreholes, C8796 and C8797, installed near the 105-KE reactor. These tests consisted of field texture column tests, <2 mm repacked column tests, batch desorption tests, and ion exchange experiments. In addition, hydraulic and physical property characterization was performed.

  16. Vibration of hydraulic machinery

    CERN Document Server

    Wu, Yulin; Liu, Shuhong; Dou, Hua-Shu; Qian, Zhongdong


    Vibration of Hydraulic Machinery deals with the vibration problem which has significant influence on the safety and reliable operation of hydraulic machinery. It provides new achievements and the latest developments in these areas, even in the basic areas of this subject. The present book covers the fundamentals of mechanical vibration and rotordynamics as well as their main numerical models and analysis methods for the vibration prediction. The mechanical and hydraulic excitations to the vibration are analyzed, and the pressure fluctuations induced by the unsteady turbulent flow is predicted in order to obtain the unsteady loads. This book also discusses the loads, constraint conditions and the elastic and damping characters of the mechanical system, the structure dynamic analysis, the rotor dynamic analysis and the system instability of hydraulic machines, including the illustration of monitoring system for the instability and the vibration in hydraulic units. All the problems are necessary for vibration pr...

  17. Characterizing fractured rock aquifers using heated Distributed Fiber-Optic Temperature Sensing to determine borehole vertical flow (United States)

    Read, T. O.; Bour, O.; Selker, J. S.; Le Borgne, T.; Bense, V.; Hochreutener, R.; Lavenant, N.


    In highly heterogeneous media, fracture network connectivity and hydraulic properties can be estimated using methods such as packer- or cross-borehole pumping-tests. Typically, measurements of hydraulic head or vertical flow in such tests are made either at a single location over time, or at a series of depths by installing a number of packers or raising or lowering a probe. We show how this often encountered monitoring problem, with current solutions sacrificing either one of temporal or spatial information, can be addressed using Distributed Temperature Sensing (DTS). Here, we electrically heat the conductive cladding materials of cables deployed in boreholes to determine the vertical flow profile. We present results from heated fiber optic cables deployed in three boreholes in a fractured rock aquifer at the much studied experimental site near Ploemeur, France, allowing detailed comparisons with alternative methods (e.g. Le Borgne et al., 2007). When submerged in water and electrically heated, the cable very rapidly reaches a steady state temperature (less than 60 seconds). The steady state temperature of the heated cable, measured using the DTS method, is then a function of the velocity of the fluid in the borehole. We find that such cables are sensitive to a wide range of fluid velocities, and thus suitable for measuring both ambient and pumped flow profiles at the Ploemeur site. The cables are then used to monitor the flow profiles during all possible configurations of: ambient flow, cross-borehole- (pumping one borehole, and observing in another), and dipole-tests (pumping one borehole, re-injection in another). Such flow data acquired using DTS may then be used for tomographic flow inversions, for instance using the approach developed by Klepikova et al., (submitted). Using the heated fiber optic method, we are able to observe the flow response during such tests in high spatial detail, and are also able to capture temporal flow dynamics occurring at the

  18. Seismic Symphonies (United States)

    Strinna, Elisa; Ferrari, Graziano


    The project started in 2008 as a sound installation, a collaboration between an artist, a barrel organ builder and a seismologist. The work differs from other attempts of sound transposition of seismic records. In this case seismic frequencies are not converted automatically into the "sound of the earthquake." However, it has been studied a musical translation system that, based on the organ tonal scale, generates a totally unexpected sequence of sounds which is intended to evoke the emotions aroused by the earthquake. The symphonies proposed in the project have somewhat peculiar origins: they in fact come to life from the translation of graphic tracks into a sound track. The graphic tracks in question are made up by copies of seismograms recorded during some earthquakes that have taken place around the world. Seismograms are translated into music by a sculpture-instrument, half a seismograph and half a barrel organ. The organ plays through holes practiced on paper. Adapting the documents to the instrument score, holes have been drilled on the waves' peaks. The organ covers about three tonal scales, starting from heavy and deep sounds it reaches up to high and jarring notes. The translation of the seismic records is based on a criterion that does match the highest sounds to larger amplitudes with lower ones to minors. Translating the seismogram in the organ score, the larger the amplitude of recorded waves, the more the seismogram covers the full tonal scale played by the barrel organ and the notes arouse an intense emotional response in the listener. Elisa Strinna's Seismic Symphonies installation becomes an unprecedented tool for emotional involvement, through which can be revived the memory of the greatest disasters of over a century of seismic history of the Earth. A bridge between art and science. Seismic Symphonies is also a symbolic inversion: the instrument of the organ is most commonly used in churches, and its sounds are derived from the heavens and

  19. Simulation of wave propagation in boreholes and radial profiling of formation elastic parameters (United States)

    Chi, Shihong

    Modern acoustic logging tools measure in-situ elastic wave velocities of rock formations. These velocities provide ground truth for time-depth conversions in seismic exploration. They are also widely used to quantify the mechanical strength of formations for applications such as wellbore stability analysis and sand production prevention. Despite continued improvements in acoustic logging technology and interpretation methods that take advantage of full waveform data, acoustic logs processed with current industry standard methods often remain influenced by formation damage and mud-filtrate invasion. This dissertation develops an efficient and accurate algorithm for the numerical simulation of wave propagation in fluid-filled boreholes in the presence of complex, near-wellbore damaged zones. The algorithm is based on the generalized reflection and transmission matrices method. Assessment of mud-filtrate invasion effects on borehole acoustic measurements is performed through simulation of time-lapse logging in the presence of complex radial invasion zones. The validity of log corrections performed with the Biot-Gassmann fluid substitution model is assessed by comparing the velocities estimated from array waveform data simulated for homogeneous and radially heterogeneous formations that sustain mud-filtrate invasion. The proposed inversion algorithm uses array waveform data to estimate radial profiles of formation elastic parameters. These elastic parameters can be used to construct more realistic near-wellbore petrophysical models for applications in seismic exploration, geo-mechanics, and production. Frequency-domain, normalized amplitude and phase information contained in array waveform data are input to the nonlinear Gauss-Newton inversion algorithm. Validation of both numerical simulation and inversion is performed against previously published results based on the Thomson-Haskell method and travel time tomography, respectively. This exercise indicates that the

  20. Handbook of hydraulic fluid technology

    CERN Document Server

    Totten, George E


    ""The Handbook of Hydraulic Fluid Technology"" serves as the foremost resource for designing hydraulic systems and for selecting hydraulic fluids used in engineering applications. Featuring new illustrations, data tables, as well as practical examples, this second edition is updated with essential information on the latest hydraulic fluids and testing methods. The detailed text facilitates unparalleled understanding of the total hydraulic system, including important hardware, fluid properties, and hydraulic lubricants. Written by worldwide experts, the book also offers a rigorous overview of h

  1. Large scale in-situ BOrehole and Geofluid Simulator (i.BOGS) for the development and testing of borehole technologies at reservoir conditions (United States)

    Duda, Mandy; Bracke, Rolf; Stöckhert, Ferdinand; Wittig, Volker


    A fundamental problem of technological applications related to the exploration and provision of geothermal energy is the inaccessibility of subsurface processes. As a result, actual reservoir properties can only be determined using (a) indirect measurement techniques such as seismic surveys, machine feedback and geophysical borehole logging, (b) laboratory experiments capable of simulating in-situ properties, but failing to preserve temporal and spatial scales, or vice versa, and (c) numerical simulations. Moreover, technological applications related to the drilling process, the completion and cementation of a wellbore or the stimulation and exploitation of the reservoir are exposed to high pressure and temperature conditions as well as corrosive environments resulting from both, rock formation and geofluid characteristics. To address fundamental and applied questions in the context of geothermal energy provision and subsurface exploration in general one of Europe's largest geoscientific laboratory infrastructures is introduced. The in-situ Borehole and Geofluid Simulator (i.BOGS) allows to simulate quasi scale-preserving processes at reservoir conditions up to depths of 5000 m and represents a large scale pressure vessel for iso-/hydrostatic and pore pressures up to 125 MPa and temperatures from -10°C to 180°C. The autoclave can either be filled with large rock core samples (25 cm in diameter, up to 3 m length) or with fluids and technical borehole devices (e.g. pumps, sensors). The pressure vessel is equipped with an ultrasound system for active transmission and passive recording of acoustic emissions, and can be complemented by additional sensors. The i.BOGS forms the basic module for the Match.BOGS finally consisting of three modules, i.e. (A) the i.BOGS, (B) the Drill.BOGS, a drilling module to be attached to the i.BOGS capable of applying realistic torques and contact forces to a drilling device that enters the i.BOGS, and (C) the Fluid.BOGS, a geofluid

  2. In situ seismic measurements in claystone at Tournemire (France) (United States)

    Zillmer, M.; Marthelot, J.-M.; Gélis, C.; Cabrera, J.; Druivenga, G.


    Compressional and shear wave seismic measurements were performed in an old railway tunnel and in galleries excavated in a 250-m-thick Toarcian claystone formation in the Tournemire experimental station (France). Three component (3C) geophones and three orthogonal orientations of the vibroseismic force source were used. Additionally, vertical seismic profiling (VSP) measurements were recorded with a 3C borehole geophone, a hydrophone and a microphone in a 159 m deep borehole (ID180) in the tunnel. The seismic data show that Toarcian claystone has strong transverse isotropy (TI) with a vertical symmetry axis. The qP, SH and qSV wave propagation velocities in horizontal directions-the plane of isotropy of the TI medium-are measured as 3550, 1850 and 1290 m s-1, respectively. The zero-offset VSP reveals that only one shear wave propagates in the vertical (depth) direction and the P- and S-wave velocities are 3100 and 1375 m s-1, respectively. Four elastic moduli of the TI medium are determined from the seismic velocities and from the bulk density of 2.53 g cm-3: c11 = 31.9 GPa, c33 = 24.3 GPa, c44 = 4.5 GPa and c66 = 8.7 GPa. A walkaway VSP with the borehole geophone at 50 m depth in borehole ID180 and shot points in the galleries leads to oblique seismic ray paths which allow us to determine the fifth elastic modulus of the TI medium to c13 = 16 GPa. The tube wave recorded by a hydrophone in the water filled lower part of the borehole propagates with 1350 m s-1, which confirms the estimate of the elastic constant c66. The analysis of body wave and surface wave data from a seismic experiment in Galerie Est shows reflections from several fracture zones in the gallery floor. The thickness of the excavation damaged zone (EDZ) in the floor of Galerie Est is estimated to 0.7 m.

  3. The 1996-2009 borehole dilatometer installations, operation, and maintenance at sites in Long Valley Caldera, CA (United States)

    Myren, Glenn; Johnston, Malcolm; Mueller, Robert


    High seismicity levels with accelerating uplift (under the resurgent dome) in Long Valley caldera in the eastern Sierra Nevada from 1989 to 1997, triggered upgrades to dilational strainmeters and other instrumentation installed in the early 1980's following a series of magnitude 6 earthquakes. This included two additional high-resolution borehole strainmeters and replacement of the failed strainmeter at Devil's Postpile. The purpose of the borehole-monitoring network is to monitor crustal deformation and other geophysical parameters associated with volcanic intrusions and earthquakes in the Long Valley Caldera. Additional instrumentation was added at these sites to improve the capability of providing continuous monitoring of the magma source under the resurgent dome. Sites were selected in regions of hard crystalline rock, where the expected signals from magmatic activity were calculated to be a maximum and the probability of an earthquake of magnitude 4 or greater is large. For the most part, the dilatometers were installed near existing arrays of surface tiltmeters, seismometers, level line, and GPS arrays. At each site, attempts are made to separate tectonic and volcanic signals from known noise sources in each instrument type. Each of these sites was planned to be a multi-parameter monitoring site, which included measurements of 3-component seismic velocity and acceleration, borehole strain, tilt, pore pressure and magnetic field. Using seismicity, geophysical knowledge, geologic and topographic maps, and geologists recommendations, lists of preliminary sites were chosen. Additional requirements were access, and telemetry constraints. When the final site choice was made, a permit was obtained from the U.S. Forest Service. Following this selection process, two new borehole sites were installed on the north and south side of the Long Valley Caldera in June of 1999. One site was located near Big Spring Campground to the east of Crestview. The second site was

  4. 30 CFR 75.388 - Boreholes in advance of mining. (United States)


    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Boreholes in advance of mining. 75.388 Section... of mining. (a) Boreholes shall be drilled in each advancing working place when the working place... cannot be examined, and before mining continues, a certified person shall, if possible, determine— (1...

  5. Distribution of boreholes in residential layouts and implications for ...

    African Journals Online (AJOL)

    The government in an attempt to solve the problem started constructing boreholes at some areas in the town as a crash programme to reduce the water supply problem. The aim of this paper is, ... The situation led to the concentration of houses close to areas with boreholes with attendant social and environmental problems.

  6. Occurrence of a Severe Acute Livestock Poisoning by Borehole ...

    African Journals Online (AJOL)

    This article reports on an outbreak of acute livestock poisoning by borehole water that occurred at Kargi in Marsabit District, Kenya in 2000. The borehole had been out of use for 3 years and after its rehabilitation, 7,000 animals died within a day after drinking the water. The most affected were shoats, cattle, camels and dogs ...

  7. Physicochemical quality of borehole water in Abonnema and its ...

    African Journals Online (AJOL)

    Physicochemical quality of borehole water in Abonnema and its public health importance. Gloria N Wokem, Token Lawson-Jack. Abstract. This study was undertaken to assess potability in relation to physicochemical quality characteristics of borehole water in Abonnema Community of Rivers State. The sampling sites were ...

  8. Characterizing Hydraulic Properties and Ground-Water Chemistry in Fractured-Rock Aquifers: A User's Manual for the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3) (United States)

    Shapiro, Allen M.


    A borehole testing apparatus has been designed to isolate discrete intervals of a bedrock borehole and conduct hydraulic tests or collect water samples for geochemical analyses. This borehole testing apparatus, referred to as the Multifunction Bedrock-Aquifer Transportable Testing Tool (BAT3), includes two borehole packers, which when inflated can form a pressure-tight seal against smooth borehole walls; a pump apparatus to withdraw water from between the two packers; a fluid-injection apparatus to inject water between the two packers; pressure transducers to monitor fluid pressure between the two packers, as well as above and below the packers; flowmeters to monitor rates of fluid withdrawal or fluid injection; and data-acquisition equipment to record and store digital records from the pressure transducers and flowmeters. The generic design of this apparatus was originally discussed in United States Patent Number 6,761,062 (Shapiro, 2004). The prototype of the apparatus discussed in this report is designed for boreholes that are approximately 6 inches in diameter and can be used to depths of approximately 300 feet below land surface. The apparatus is designed to fit in five hard plastic boxes that can be shipped by overnight freight car-riers. The equipment can be assembled rapidly once it is removed from the shipping boxes, and the length of the test interval (the distance between the two packers) can be adjusted to account for different borehole conditions without reconfiguring the downhole components. The downhole components of the Multifunction BAT3 can be lowered in a borehole using steel pipe or a cable; a truck mounted winch or a winch and tripod can be used for this purpose. The equipment used to raise and lower the downhole components of the Multifunction BAT3 must be supplied on site, along with electrical power, a compressor or cylinders of compressed gas to inflate the packers and operate downhole valves, and the proper length of tubing to connect the

  9. Electrical and Magnetic Imaging of Proppants in Shallow Hydraulic Fractures (United States)

    Denison, J. L. S.; Murdoch, L. C.; LaBrecque, D. J.; Slack, W. W.


    Hydraulic fracturing is an important tool to increase the productivity of wells used for oil and gas production, water resources, and environmental remediation. Currently there are relatively few tools available to monitor the distribution of proppants within a hydraulic fracture, or the propagation of the fracture itself. We have been developing techniques for monitoring hydraulic fractures by injecting electrically conductive, dielectric, or magnetically permeable proppants. We then use the resulting contrast with the enveloping rock to image the proppants using geophysical methods. Based on coupled laboratory and numerical modeling studies, three types of proppants were selected for field evaluation. Eight hydraulic fractures were created near Clemson, SC in May of 2015 by injecting specialized proppants at a depth of 1.5 m. The injections created shallow sub-horizontal fractures extending several meters from the injection point.Each cell had a dense array of electrodes and magnetic sensors on the surface and four shallow vertical electrode arrays that were used to obtain data before and after hydraulic fracturing. Net vertical displacement and transient tilts were also measured. Cores from 130 boreholes were used to characterize the general geometries, and trenching was used to characterize the forms of two of the fractures in detail. Hydraulic fracture geometries were estimated by inverting pre- and post-injection geophysical data. Data from cores and trenching show that the hydraulic fractures were saucer-shaped with a preferred propagation direction. The geophysical inversions generated images that were remarkably similar in form, size, and location to the ground truth from direct observation. Displacement and tilt data appear promising as a constraint on fracture geometry.

  10. A hybrid method for estimating the state of stress in ICDP-sponsored deep vertical boreholes (Invited) (United States)

    Haimson, B. C.


    Hydraulic fracturing (HF) has been the method of choice for estimating the state of stress around deep vertical boreholes for the last four decades, starting with the Rangely, Colorado and the Michigan Basin measurements (Haimson, Tectonophysics, 1975; JGR, 1977). However, recently considerable controversy has developed regarding the reliability of the maximum horizontal stress σH as derived from the classical interpretation of HF recorded data, especially at great depths. In addition, in very deep holes, HF tests are sometimes incomplete, yielding only estimates of the minimum horizontal stress σh magnitude (example: KTB, Germany; see Brudy et al, JGR 1997). As a result, an alternative hybrid method for constraining all three principal in situ stresses and their directions around deep vertical boreholes has been developed and used at several ICDP (International Continental Scientific Drilling Program) sites. It involves HF tests for estimating σh, provided hydrofractures are vertical. The vertical stress σv is computed from the weight of the overlying strata. Assessing σH and its direction involves the use of geophysical logging such as the Borehole Acoustic Televiewer or the Formation Micro Imager. They capture oriented images of borehole breakouts, from which the oriented breakout span as it varies with depth is obtained. Laboratory true triaxial tests on specimens prepared out of core samples render the appropriate strength criterion for rock at the borehole wall. Using the condition of limit equilibrium between the local state of stress at the breakout-borehole intersections and the strength criterion, a non linear equation emerges from which the maximum horizontal principal stress is derived, thus completing the estimation of the prevailing state of stress. The use of this hybrid method is restricted to deep vertical boreholes that produce vertical hydrofractures and in which breakouts develop, with dimensions not affected by the drilling mud. Two ICDP

  11. Seismic signatures of the Lodgepole fractured reservoir in Utah-Wyoming overthrust belt

    Energy Technology Data Exchange (ETDEWEB)

    Parra, J.; Collier, H.; Angstman, B.


    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.

  12. Tension permeameter for deep borehole characterization

    Energy Technology Data Exchange (ETDEWEB)

    Sisson, J.B.; Honeycutt, T.K. [EG and G Idaho, Inc., Idaho Falls, ID (United States)


    The permeability of geologic materials is an important variable for estimating the rate of transport of contaminants from waste sites. To date, permeability has been estimated in the laboratory from measurements made on small cores, under hydrologic conditions far removed from those of the field. Available field instruments cannot estimate permeabilities at depth under ambient conditions. The authors have constructed a borehole tension permeameter that is capable of operating at near field conditions and at depths of more than 30 m. The tension permeameter consists of a syringe pump, lightweight packer, semipermeable membrane, and pressure transducer, all controlled by a programmable logic controller. Water is metered at a fixed rate through the membrane while monitoring tension. The permeability is estimated from the steady pumping rate for the membrane geometry used at the measured water tension. The permeameter was used to estimate the permeability of Pancheri sandy loam at tensions of 0 to 150 cm.

  13. Borehole plugging materials development program, report 2

    Energy Technology Data Exchange (ETDEWEB)

    Gulick, C.W. Jr.; Boa, J.A. Jr.; Walley, D.M.; Buck, A.D.


    The data for 2 yr of grout mixtures durability studies developed for the borehole plugging program of the Nuclear Waste Isolation Pilot Plant (WIPP) are reported. In addition, data for 1 yr of durability studies of grout mixture field samples used to plug the ERDA No. 10 exploratory drill hole near the WIPP site are included. The grout samples and the data do not show any evidence of deterioration during the durability studies that include exposure to brine at both ambient and elevated temperatures. The data include strength, compressional wave velocity, dynamic modulus, expansion, weight change, porosity, permeability, bond strength, chemical analysis of cements, and petrographic examinations. The work was performed at the Concrete Division of the Structures Laboratory of the US Army Engineer Waterways Experiments Station (WES), Vicksburg, Mississippi. The work is continuing at WES.

  14. Water Hydraulic Systems

    DEFF Research Database (Denmark)

    Conrad, Finn


    The paper presents research results using IT-Tools for CAD and dynamic modelling, simulation, analysis, and design of water hydraulic actuators for motion control of machines, lifts, cranes and robots. Matlab/Simulink and CATIA are used as IT-Tools. The contributions include results from on......-going research projects on fluid power and mechatronics based on tap water hydraulic servovalves and linear servo actuators and rotary vane actuators for motion control and power transmission. Development and design a novel water hydraulic rotary vane actuator for robot manipulators. Proposed mathematical...... modelling, control and simulation of a water hydraulic rotary vane actuator applied to power and control a two-links manipulator and evaluate performance. The results include engineering design and test of the proposed simulation models compared with IHA Tampere University’s presentation of research...

  15. FEMA DFIRM Hydraulic Structures (United States)

    Minnesota Department of Natural Resources — This layer and accompanying attribute table is required whenever hydraulic structures are shown in the flood profile. It is also required if levees are shown on the...

  16. Conductive fracture mapping. A study on the correlation between borehole TV- and radar images and difference flow logging results in borehole KLX02

    Energy Technology Data Exchange (ETDEWEB)

    Carlsten, S.; Straahle, A.; Ludvigson, Jan-Erik [GEOSIGMA AB, Uppsala (Sweden)


    angle and the recorded borehole length were used as the most important parameters. The accuracy of the recorded length (depth) of the interpreted radar reflectors is rather poor compared to the BIPS-logging. A total number of 6 radar reflectors (of the 12 identified) could be correlated with BIPS-features and DIFF-flow anomalies. As above, the correlated BIPS-features were classified as open fractures or in some cases as veins in the rock. The correlation study indicates that the number of features mapped as 'open fractures' together with 'fractures with cavities' in the BIPS characterisation, correspond to almost 70% of the total number of interpreted flow anomalies from the DIFF-logging in this borehole interval. This figure increases to almost 80% if uncertain flow anomalies below the measurement limit are excluded. The remainder of the flow anomalies correspond to features mapped as 'altered fractures or veins' and 'dull fractures or veins 'in the BIPS- characterisation. The estimated lateral extent of the correlated radar reflectors is about 10-30 m. The latter figure corresponds to the estimated persistence (depth of penetration)of the radar images in this case. The dominant strike of the interpreted flow anomalies is towards WNW-NW as determined from the BIPS- and radar characterisation. This result is in good agreement with previous investigations of the orientation of water-conductive fractures at Aespoe. Thus, it is concluded that the interpreted flow anomalies from the DIFF-log are representative for the dominating hydraulic conditions in the rock. The accuracy of the depth recording is one of the most important parameter and also the one that, in this study, contributes to the largest error when comparing different methods. One of the conclusions of this study is to diminish the error by using efficient measuring wheels in order to avoid sliding of the cable during logging. A new method for making length registration

  17. Bibliography of borehole geophysics as applied to ground-water hydrology (United States)

    Taylor, Ticie A.; Dey, Joyce A.


    Most of the references on borehole geophysics that are relevant to ground-water hydrology are contained in this bibliography, but it does not include every reference that is available under each subject heading; the literature is much too extensive to compile a complete listing. Some of the references may appear under more than one subject heading because the references commonly relate to more than one main topic. Many articles have been cross-referenced in order to assist the reader in locating an article. For example, the article entitled, 'Application of the acoustic televiewer to the characterization of hydraulic fractures in geothermal wells' is listed under both 'Acoustic televiewer,' and 'Geothermal'. The bibliography is intended to lead the reader to other articles on borehole-geophysical logging and related subjects, because each article cited also will have a list of references, which may be more specialized, covering many subjects with related applications, such as physics, mathematics, chemistry, geology, electronics, acoustics, hydrology, and surface geophysics. However, not all of these related subject headings could be included in this bibliography.

  18. Inverse modeling of hydraulic tests in fractured crystalline rock based on a transition probability geostatistical approach (United States)

    Blessent, Daniela; Therrien, René; Lemieux, Jean-Michel


    This paper presents numerical simulations of a series of hydraulic interference tests conducted in crystalline bedrock at Olkiluoto (Finland), a potential site for the disposal of the Finnish high-level nuclear waste. The tests are in a block of crystalline bedrock of about 0.03 km3 that contains low-transmissivity fractures. Fracture density, orientation, and fracture transmissivity are estimated from Posiva Flow Log (PFL) measurements in boreholes drilled in the rock block. On the basis of those data, a geostatistical approach relying on a transitional probability and Markov chain models is used to define a conceptual model based on stochastic fractured rock facies. Four facies are defined, from sparsely fractured bedrock to highly fractured bedrock. Using this conceptual model, three-dimensional groundwater flow is then simulated to reproduce interference pumping tests in either open or packed-off boreholes. Hydraulic conductivities of the fracture facies are estimated through automatic calibration using either hydraulic heads or both hydraulic heads and PFL flow rates as targets for calibration. The latter option produces a narrower confidence interval for the calibrated hydraulic conductivities, therefore reducing the associated uncertainty and demonstrating the usefulness of the measured PFL flow rates. Furthermore, the stochastic facies conceptual model is a suitable alternative to discrete fracture network models to simulate fluid flow in fractured geological media.

  19. A compendium of P- and S-wave velocities from surface-to-borehole logging; summary and reanalysis of previously published data and analysis of unpublished data (United States)

    Boore, David M.


    For over 28 years, the U.S. Geological Survey (USGS) has been acquiring seismic velocity and geologic data at a number of locations in California, many of which were chosen because strong ground motions from earthquakes were recorded at the sites. The method for all measurements involves picking first arrivals of P- and S-waves from a surface source recorded at various depths in a borehole (as opposed to noninvasive methods, such as the SASW method [e.g., Brown et al., 2002]). The results from most of the sites are contained in a series of U.S. Geological Survey Open-File Reports (see References). Until now, none of the results have been available as computer files, and before 1992 the interpretation of the arrival times was in terms of piecemeal interval velocities, with no attempt to derive a layered model that would fit the travel times in an overall sense (the one exception is Porcella, 1984). In this report I reanalyze all of the arrival times in terms of layered models for P- and for S-wave velocities at each site, and I provide the results as computer files. In addition to the measurements reported in the open-file reports, I also include some borehole results from other reports, as well as some results never before published. I include data for 277 boreholes (at the time of this writing; more will be added to the web site as they are obtained), all in California (I have data from boreholes in Washington and Utah, but these will be published separately). I am also in the process of interpreting travel time data obtained using a seismic cone penetrometer at hundreds of sites; these data can be interpreted in the same way of those obtained from surface-to-borehole logging. When available, the data will be added to the web site (see below for information on obtaining data from the World Wide Web (WWW)). In addition to the basic borehole data and results, I provide information concerning strong-motion stations that I judge to be close enough to the boreholes

  20. Cyclic high temperature heat storage using borehole heat exchangers (United States)

    Boockmeyer, Anke; Delfs, Jens-Olaf; Bauer, Sebastian


    The transition of the German energy supply towards mainly renewable energy sources like wind or solar power, termed "Energiewende", makes energy storage a requirement in order to compensate their fluctuating production and to ensure a reliable energy and power supply. One option is to store heat in the subsurface using borehole heat exchangers (BHEs). Efficiency of thermal storage is increasing with increasing temperatures, as heat at high temperatures is more easily injected and extracted than at temperatures at ambient levels. This work aims at quantifying achievable storage capacities, storage cycle times, injection and extraction rates as well as thermal and hydraulic effects induced in the subsurface for a BHE storage site in the shallow subsurface. To achieve these aims, simulation of these highly dynamic storage sites is performed. A detailed, high-resolution numerical simulation model was developed, that accounts for all BHE components in geometrical detail and incorporates the governing processes. This model was verified using high quality experimental data and is shown to achieve accurate simulation results with excellent fit to the available experimental data, but also leads to large computational times due to the large numerical meshes required for discretizing the highly transient effects. An approximate numerical model for each type of BHE (single U, double U and coaxial) that reduces the number of elements and the simulation time significantly was therefore developed for use in larger scale simulations. The approximate numerical model still includes all BHE components and represents the temporal and spatial temperature distribution with a deviation of less than 2% from the fully discretized model. Simulation times are reduced by a factor of ~10 for single U-tube BHEs, ~20 for double U-tube BHEs and ~150 for coaxial BHEs. This model is then used to investigate achievable storage capacity, injection and extraction rates as well as induced effects for

  1. Back Analysis of Rock Hydraulic Fracturing by Coupling Numerical Model and Computational Intelligent Technology

    Directory of Open Access Journals (Sweden)

    Shaojun Li


    Full Text Available Hydraulic fracturing is widely used to determine in situ stress of rock engineering. In this paper we propose a new method for simultaneously determining the in situ stress and elastic parameters of rock. The method utilizing the hydraulic fracturing numerical model and a computational intelligent method is proposed and verified. The hydraulic fracturing numerical model provides the samples which include borehole pressure, in situ stress, and elastic parameters. A computational intelligent method is applied in back analysis. A multioutput support vector machine is used to map the complex, nonlinear relationship between the in situ stress, elastic parameters, and borehole pressure. The artificial bee colony algorithm is applied in back analysis to find the optimal in situ stress and elastic parameters. The in situ stress is determined using the proposed method and the results are compared with those of the classic breakdown formula. The proposed method provides a good estimate of the relationship between the in situ stress and borehole pressure and predicts the maximum horizontal in situ stress with high precision while considering the influence of pore pressure without the need to estimate Biot’s coefficient and other parameters.

  2. BASIMO - Borehole Heat Exchanger Array Simulation and Optimization Tool (United States)

    Schulte, Daniel O.; Bastian, Welsch; Wolfram, Rühaak; Kristian, Bär; Ingo, Sass


    Arrays of borehole heat exchangers are an increasingly popular source for renewable energy. Furthermore, they can serve as borehole thermal energy storage (BTES) systems for seasonally fluctuating heat sources like solar thermal energy or district heating grids. The high temperature level of these heat sources prohibits the use of the shallow subsurface for environmental reasons. Therefore, deeper reservoirs have to be accessed instead. The increased depth of the systems results in high investment costs and has hindered the implementation of this technology until now. Therefore, research of medium deep BTES systems relies on numerical simulation models. Current simulation tools cannot - or only to some extent - describe key features like partly insulated boreholes unless they run fully discretized models of the borehole heat exchangers. However, fully discretized models often come at a high computational cost, especially for large arrays of borehole heat exchangers. We give an update on the development of BASIMO: a tool, which uses one dimensional thermal resistance and capacity models for the borehole heat exchangers coupled with a numerical finite element model for the subsurface heat transport in a dual-continuum approach. An unstructured tetrahedral mesh bypasses the limitations of structured grids for borehole path geometries, while the thermal resistance and capacity model is improved to account for borehole heat exchanger properties changing with depth. Thereby, partly insulated boreholes can be considered in the model. Furthermore, BASIMO can be used to improve the design of BTES systems: the tool allows for automated parameter variations and is readily coupled to other code like mathematical optimization algorithms. Optimization can be used to determine the required minimum system size or to increase the system performance.

  3. Combined seismic and radar investigation to define ice properties and structure of a cold alpine site (United States)

    Eisen, O.; Bohleber, P.; Drews, R.; Heilig, A.; Hofstede, C.


    The cold alpine saddle Colle Gnifetti, Monte Rosa, Swiss-Italian Alps resembles very much polar and subpolar ice masses in terms of glaciological conditions. It has been the site for several ice-core drilling campaigns over more than 20 years to determine paleoclimatological and glaciological conditions. To investigate the feasibility of geophysical methods for improved characterization of ice masses surrounding borehole and ice-core sites, a combined active reflection seismic and ground-penetrating radar pilot study has been carried out in summer 2008. Aims are the characterization of density, internal layering, seismic and radar wave speed and attenuation, identification of anisotropic features (like crystal orientation or bubble content and shape). Here we present the overall setup and first results. Seismic and GPR profiles were centered on an existing borehole location covering the full ice thickness of 62 m. Active seismics was carried out with 24-channel 3-m spacing recording, using a Seismic Impulse Source System (SISSY) along two profiles parallel and perpendicular to the ice-flow direction. The same profiles were complemented with GPR measurements utilizing 250, 500 MHz frequencies. Additionally, circular profiles with 250, 500 and 800 MHz were carried out circumferencing the borehole to detect anisotropic features.

  4. Development of a new semi-analytical model for cross-borehole flow experiments in fractured media (United States)

    Roubinet, Delphine; Irving, James; Day-Lewis, Frederick D.


    Analysis of borehole flow logs is a valuable technique for identifying the presence of fractures in the subsurface and estimating properties such as fracture connectivity, transmissivity and storativity. However, such estimation requires the development of analytical and/or numerical modeling tools that are well adapted to the complexity of the problem. In this paper, we present a new semi-analytical formulation for cross-borehole flow in fractured media that links transient vertical-flow velocities measured in one or a series of observation wells during hydraulic forcing to the transmissivity and storativity of the fractures intersected by these wells. In comparison with existing models, our approach presents major improvements in terms of computational expense and potential adaptation to a variety of fracture and experimental configurations. After derivation of the formulation, we demonstrate its application in the context of sensitivity analysis for a relatively simple two-fracture synthetic problem, as well as for field-data analysis to investigate fracture connectivity and estimate fracture hydraulic properties. These applications provide important insights regarding (i) the strong sensitivity of fracture property estimates to the overall connectivity of the system; and (ii) the non-uniqueness of the corresponding inverse problem for realistic fracture configurations.

  5. Model Analysis of Low-Level Actinide Waste Disposal in Deep Boreholes (United States)

    Glascoe, L. G.; Wolfsberg, A. V.


    Deep borehole disposal is considered as a possible mechanism for the safe removal of Greater Than Class C (GTCC) low level actinide waste (Am-241, Pu-239, and Pu-238). Of the three actinides in GTCC waste, only Pu-239 has a half-life greater than 500 years and, thus, will have the longest environmental presence. However, Am-241 and Pu-238 have the potential to create most of the heat associated with GTCC waste disposal in deep boreholes. Therefore, this study considers the nonisothermal release and subsequent migration toward a pumping well of the most persistent radionuclide, Pu-239, from a deep emplacement borehole taking into account the heat created by decay of all three actinides. The Finite-Element Heat- and Mass-Transfer code, FEHM, is employed to simulate three-dimensional, non-isothermal flow and solute transport using particle tracking. Multiple scenarios considering various source emplacement depths, aquifer properties, and hydraulic conditions are evaluated in a sensitivity analysis that seeks to demonstrate competing and offsetting processes affecting the concentration of Pu-239 in the pumped well 100 m down gradient from the borehole source. In general, lower groundwater fluxes, associated with lower gradients and/or lower aquifer permeabilities, lead to less dissolution of the source waste. However, conditions of decreasing groundwater flux also create larger sized capture zones by the pumping well, thus escalating the likelihood of pumping contaminants originating from a source deeper than the pumping well. Retardation by sorption of Pu-239, both in alluvial aquifers and following diffusion from fractures in a tuff aquifer, plays an important role both in delaying radionuclide migration and in reducing the peak aqueous concentration at the pumping well. This work was performed under the auspices of the U.S. Department of Energy by University of California Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48. This work was

  6. Shock-induced wave propagation over porous and fractured borehole zones : Theory and experiments

    NARCIS (Netherlands)

    Fan, H.; Smeulders, D.M.J.


    Borehole waves are strongly affected by adjacent porous zones or by fractures intersecting the borehole. A theoretical description for both porous and fracture zones is possible based on the introduction of an effective borehole fluid bulk modulus, characterizing the wave attenuation via borehole

  7. Catalog of boreholes from Russia and Mongolia, Version 1 (United States)

    National Aeronautics and Space Administration — This catalog of boreholes from across Russia and Mongolia includes those published in papers and monographs as well as other literature of limited circulation. The...

  8. Global Database of Borehole Temperatures and Climate Reconstructions - CA-0003 (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Data collected from borehole site CA-0003. For an accurate assessment of the relative roles of natural variability and anthropogenic influence in the Earth's...

  9. Methodology for Radiological Risk Assessment of Deep Borehole Disposal Operations

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest; Su, Jiann-Cherng; Peretz, Fred(ORNL)


    The primary purpose of the preclosure radiological safety assessment (that this document supports) is to identify risk factors for disposal operations, to aid in design for the deep borehole field test (DBFT) engineering demonstration.

  10. The assessment of seismic hazard for Gori, (Georgia) and preliminary studies of seismic microzonation (United States)

    Gogoladze, Z.; Moscatelli, M.; Giallini, S.; Avalle, A.; Gventsadze, A.; Kvavadze, N.; Tsereteli, N.


    Seismic risk is a crucial issue for South Caucasus, which is the main gateway between Asia and Europe. The goal of this work is to propose new methods and criteria for defining an overall approach aimed at assessing and mitigating seismic risk in Georgia. In this reguard seismic microzonation represents a highly useful tool for seismic risk assessmentin land management, for design of buildings or structures and for emergency planning.Seismic microzonation assessment of local seismic hazard,which is a component of seismicity resulting from specific local characteristics which cause local amplification and soil instability, through identification of zones with seismically homogeneous behavior. This paper presents the results of preliminary study of seismic microzonation of Gori, Georgia. Gori is and is located in the Shida Kartli region and on both sides of Liachvi and Mtkvari rivers, with area of about 135 km2around the Gori fortress. Gori is located in Achara-Trialeti fold-thrust belt, that is tectonically unstable. Half of all earthquakes in Gori area with magnitude M≥3.5 have happened along this fault zone and on basis of damage caused by previous earthquakes, this territory show the highest level of risk (the maximum value of direct losses) in central part of the town. The seismic microzonation map of level 1 for Gori was carried out using: 1) Already available data (i.e., topographic map and boreholes data), 2) Results of new geological surveys and 3) Geophysical measurements (i.e., MASW and noise measurements processed with HVSR technique). Our preliminary results highlight the presence of both stable zones susceptible to local amplifications and unstable zones susceptible to geological instability. Our results are directed to establish set of actions aimed at risk mitigation before initial onset of emergency, and to management of the emergency once the seismic event has occurred. The products obtained, will contain the basic elements of an integrated system

  11. Experimental and Numerical Comparison of Two Borehole Heat Exchangers

    DEFF Research Database (Denmark)

    Alberdi Pagola, Maria; Poulsen, Søren Erbs


    This report outlines key results from a comparative study of two different pipe borehole heat exchanger (BHE) configurations. The work was carried out by VIA University College and in collaboration with GM Plast A/S.......This report outlines key results from a comparative study of two different pipe borehole heat exchanger (BHE) configurations. The work was carried out by VIA University College and in collaboration with GM Plast A/S....

  12. Bond strength of cementitious borehole plugs in welded tuff

    Energy Technology Data Exchange (ETDEWEB)

    Akgun, H.; Daemen, J.J.K. [Arizona Univ., Tucson, AZ (USA). Dept. of Mining and Geological Engineering


    Axial loads on plugs or seals in an underground repository due to gas, water pressures and temperature changes induced subsequent to waste and plug emplacement lead to shear stresses at the plug/rock contact. Therefore, the bond between the plug and rock is a critical element for the design and effectiveness of plugs in boreholes, shafts or tunnels. This study includes a systematic investigation of the bond strength of cementitious borehole plugs in welded tuff. Analytical and numerical analysis of borehole plug-rock stress transfer mechanics is performed. The interface strength and deformation are studied as a function of Young`s modulus ratio of plug and rock, plug length and rock cylinder outside-to-inside radius ratio. The tensile stresses in and near an axially loaded plug are analyzed. The frictional interface strength of an axially loaded borehole plug, the effect of axial stress and lateral external stress, and thermal effects are also analyzed. Implications for plug design are discussed. The main conclusion is a strong recommendation to design friction plugs in shafts, drifts, tunnels or boreholes with a minimum length to diameter ratio of four. Such a geometrical design will reduce tensile stresses in the plug and in the host rock to a level which should minimize the risk of long-term deterioration caused by excessive tensile stresses. Push-out tests have been used to determine the bond strength by applying an axial load to cement plugs emplaced in boreholes in welded tuff cylinders. A total of 130 push-out tests have been performed as a function of borehole size, plug length, temperature, and degree of saturation of the host tuff. The use of four different borehole radii enables evaluation of size effects. 119 refs., 42 figs., 20 tabs.

  13. Active and passive seismic investigations in Alpine Permafrost at Hoher Sonnblick (Austria) (United States)

    Steiner, Matthias; Maierhofer, Theresa; Pfeiler, Stefan; Chwatal, Werner; Behm, Michael; Reisenhofer, Stefan; Schöner, Wolfgang; Straka, Wolfgang; Flores Orozco, Adrian


    Different geophysical measurements have been applied at the Hoher Sonnblick study area to gain information about permafrost distribution as well as heterogeneities controlling heat circulation, in the frame of the ÖAW-AtmoPerm project, which aims at the understanding the impacts of atmospheric extreme events on the thermal state of the active layer. Electrical Resistivity Tomography (ERT) has been widely accepted as a suitable method to characterize permafrost processes; however, limitations are imposed due to the challenges to inject high current densities in the frozen periods and the loss of resolution of electrical images at depth require the application of further geophysical methods. To overcome such problems, we investigate here the application of active and seismic methods. Seismic campaigns were performed using permanent borehole and temporarily installed surface geophones. A total of 15 borehole geophones are installed at depths of 1 m, 2 m, 5 m, 10 m and 20 m in three boreholes which are separated by a horizontal distance of 30 m between each other. Active measurements utilized 41 surface and 15 borehole geophones and a total of 199 excitation points. Surface geophones were laid out along two crossing lines with lengths of 92 m and 64 m, respectively. The longer line was placed directly along the borehole transect and the shorter one was oriented perpendicular to it. Hammer blows were performed with a spacing of 1 m inline the geophones and 4 m in crosslines rotated by 45 degrees, permitting 3D acquisition geometry. In addition to the active sources, data loggers connected to the borehole geophones permitted the collection of continuous 36-hours datasets for two different thermal conditions. Seismic ambient noise interferometry is applied to this data and aims at the identification of velocity changes in the subsurface related to seasonal changes of the active layer. A potential source of ambient seismic energy is the noise excited by hikers and the

  14. Hydraulics and pneumatics

    CERN Document Server

    Parr, Andrew


    Nearly all industrial processes require objects to be moved, manipulated or subjected to some sort of force. This is frequently accomplished by means of electrical equipment (such as motors or solenoids), or via devices driven by air (pneumatics) or liquids (hydraulics).This book has been written by a process control engineer as a guide to the operation of hydraulic and pneumatic systems for all engineers and technicians who wish to have an insight into the components and operation of such a system.This second edition has been fully updated to include all recent developments su

  15. Discrimination of Earthquake and Blast Seismicity in Western Alberta (United States)

    Spriggs, N.; Law, A.; Yenier, E.; Reynen, A.; Baturan, D.


    Recorded seismicity in western Alberta is caused by natural and induced earthquakes or blast events from mining and quarry operations. Accurate discrimination of earthquakes from blast events is crucial for evaluating recent seismicity with respect to the historical catalog and for assessing seismic hazards associated with naturally occurring or induced seismicity. In general, blast events are discriminated from earthquakes based on their proximity to active mines and quarries in addition to day-of-week and time-of-day timing patterns. In some parts of western Alberta, however, seismicity originates in regions with active mines, historical earthquake seismicity, and hydraulic fracturing operations. Based on timing patterns or event locations alone, natural or induced seismicity may be misidentified as mining activity. Several studies report that relative differences in Fourier or response spectra can be used to discriminate blast and earthquake events. Other studies report that the relative timing and amplitude of seismic phases may provide useful metrics for classifying blast events. Here we propose an alternative method that accounts for both differences in phase spectra and phase timing and amplitude. In particular, we evaluate the normalized time integral for characteristic functions of particle motion from confirmed blast and earthquake events recorded by regional Alberta seismic networks. We then use these time-integral profiles to re-classify events that are initially categorized as suspected blasts based on timing pattern and event location indicators.

  16. Seismic experiments, nuclear dismantlement go hand in hand in Kazakhstan (United States)

    Leith, William; Kluchko, Luke J.

    Unique seismic experiments involving large chemical explosions at different depths have been conducted in Kazakhstan, thanks to nuclear dismantlement activity there. Collaborative efforts of several bodies have provided this creative, cost-efficient extension of the dismantling work, improving technical monitoring and verification of the Comprehensive Test Ban Treaty (CTBT).For the past several years, the Defense Special Weapons Agency (DSWA) has been closing the nuclear test tunnels and bore-holes at the former Soviet nuclear test site nearSemipalatinsk, eastern Kazakhstan, as part of the Nunn-Lugar Cooperative Threat Reduction (CTR) Program. The existence of this program and the infrastructure that was in place to implement it made it possible to conduct the seismic experiments. As a result, benchmark data have been collected on the variations in seismic signals from explosions at different burial depths.

  17. Development of the Multi-Level Seismic Receiver (MLSR)

    Energy Technology Data Exchange (ETDEWEB)

    Sleefe, G.E.; Engler, B.P.; Drozda, P.M.; Franco, R.J.; Morgan, J.


    The Advanced Geophysical Technology Department (6114) and the Telemetry Technology Development Department (2664) have, in conjunction with the Oil Recovery Technology Partnership, developed a Multi-Level Seismic Receiver (MLSR) for use in crosswell seismic surveys. The MLSR was designed and evaluated with the significant support of many industry partners in the oil exploration industry. The unit was designed to record and process superior quality seismic data operating in severe borehole environments, including high temperature (up to 200{degrees}C) and static pressure (10,000 psi). This development has utilized state-of-the-art technology in transducers, data acquisition, and real-time data communication and data processing. The mechanical design of the receiver has been carefully modeled and evaluated to insure excellent signal coupling into the receiver.

  18. Optimizing Seismic Monitoring Networks for EGS and Conventional Geothermal Projects (United States)

    Kraft, Toni; Herrmann, Marcus; Bethmann, Falko; Stefan, Wiemer


    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.

  19. Geophysical borehole logging and optical imaging of the boreholes KR34, KR35 and KR36, at Olkiluoto 2005

    Energy Technology Data Exchange (ETDEWEB)

    Majapuro, J. [Suomen Malmi Oy, Espoo (Finland)


    Suomen Malmi Oy conducted geophysical borehole logging and optical imaging surveys of the boreholes KR34, KR35 and KR36 at the Olkiluoto site in Eurajoki during May - June 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are magnetic susceptibility, natural gamma radiation, gamma-gamma density, single point resistance, Wenner-resistivity, borehole radar, full waveform sonic and optical imaging. The assignment included the field work of all surveys, interpretation and processing of the acoustic and borehole radar data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

  20. Advanced Seismic While Drilling System

    Energy Technology Data Exchange (ETDEWEB)

    Robert Radtke; John Fontenot; David Glowka; Robert Stokes; Jeffery Sutherland; Ron Evans; Jim Musser


    A breakthrough has been discovered for controlling seismic sources to generate selectable low frequencies. Conventional seismic sources, including sparkers, rotary mechanical, hydraulic, air guns, and explosives, by their very nature produce high-frequencies. This is counter to the need for long signal transmission through rock. The patent pending SeismicPULSER{trademark} methodology has been developed for controlling otherwise high-frequency seismic sources to generate selectable low-frequency peak spectra applicable to many seismic applications. Specifically, we have demonstrated the application of a low-frequency sparker source which can be incorporated into a drill bit for Drill Bit Seismic While Drilling (SWD). To create the methodology of a controllable low-frequency sparker seismic source, it was necessary to learn how to maximize sparker efficiencies to couple to, and transmit through, rock with the study of sparker designs and mechanisms for (a) coupling the sparker-generated gas bubble expansion and contraction to the rock, (b) the effects of fluid properties and dynamics, (c) linear and non-linear acoustics, and (d) imparted force directionality. After extensive seismic modeling, the design of high-efficiency sparkers, laboratory high frequency sparker testing, and field tests were performed at the University of Texas Devine seismic test site. The conclusion of the field test was that extremely high power levels would be required to have the range required for deep, 15,000+ ft, high-temperature, high-pressure (HTHP) wells. Thereafter, more modeling and laboratory testing led to the discovery of a method to control a sparker that could generate low frequencies required for deep wells. The low frequency sparker was successfully tested at the Department of Energy Rocky Mountain Oilfield Test Center (DOE RMOTC) field test site in Casper, Wyoming. An 8-in diameter by 26-ft long SeismicPULSER{trademark} drill string tool was designed and manufactured by TII

  1. Analysis motion of borehole-expander - device for densifying subsurface walls of boreholes (United States)

    Pavlov, G. V.; Kalmova, M. A.; Pischulev, A. A.; Panfilov, D. A.


    The paper introduces an algorithm for analyzing the following solids of rotation and their motion: a bearing roller and a borehole-expander - a device for densifying subsurface walls of boreholes. These devices are moving in the environment with rheological properties typical for the Kelvin model, with nonholonomic constraints that impose restrictions on the velocity of the disk points. The research presents both mathematical models of the standard viscoelastic hereditary-deformed cylinder and a weakly singular model proposed by A.R. Rzhanitsin, representing a nonautonomous system of differential equations in the form of Routh. The fact that this system is nonautonomous complicates its sustainability analysis. The presentation of a rheological force in a differential form does not lead to a system of equations in the form of Chaplygin. The solution was found by numerical integration. The solution is multivariant as one initial value of generalized coordinates and generalized accelerations corresponds to a series of initial generalized speeds. It is shown that the disk is not able to fall in the course of motion because its point of contact being in a radial vibration is still within the tension region of the cylinder wall.

  2. Hydraulic Analyses, Rains County, Texas (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...


    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating flood discharges for a flood insurance...

  4. Effective Media for Transversely Isotropic Models Based on Homogenization Theory: With Applications to Borehole Sonic Logs (United States)

    Lin, Chuangxin; Saleh, Ramin; Milkereit, Bernd; Liu, Qinya


    Sonic log records, including measurements of wave speeds in boreholes, provide critical input to the geological, geophysical, and petrophysical studies of a region under exploration. 1D background models are routinely built based on sonic log records for applications such as seismic imaging of hydrocarbon reservoirs and microseismic source inversions. Smoothing or `upscaling' techniques are required to produce models in coarser scales than the very fine layers in the raw log data. In this paper, we follow the recently popular homogenization theory, derive its application to the special case of 1D TI models for both P-SV and SH waves, and show that it is consistent with the Backus averaging technique commonly used to upscale 1D fine-layered models. We examine a study case of sonic log data from a well in the Horn River Basin in northeastern British Columbia, a region known for its tight shale-gas deposit. We demonstrate the computational accuracy and efficiency gained by proper upscaling procedures for spectral-element simulations of seismic wave propagation, and discuss the effect of control parameters on wavefield recovery.

  5. Modelling of Hydraulic Robot

    DEFF Research Database (Denmark)

    Madsen, Henrik; Zhou, Jianjun; Hansen, Lars Henrik


    This paper describes a case study of identifying the physical model (or the grey box model) of a hydraulic test robot. The obtained model is intended to provide a basis for model-based control of the robot. The physical model is formulated in continuous time and is derived by application...

  6. Water Treatment Technology - Hydraulics. (United States)

    Ross-Harrington, Melinda; Kincaid, G. David

    One of twelve water treatment technology units, this student manual on hydraulics provides instructional materials for three competencies. (The twelve units are designed for a continuing education training course for public water supply operators.) The competencies focus on the following areas: head loss in pipes in series, function loss in…

  7. Rock property estimates using multiple seismic attributes and neural networks; Pegasus Field, West Texas

    Energy Technology Data Exchange (ETDEWEB)

    Schuelke, J.S.; Quirein, J.A.; Sarg, J.F.


    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.

  8. Thermal modelling of borehole heat exchangers and borehole thermal energy stores; Zur thermischen Modellierung von Erdwaermesonden und Erdsonden-Waermespeichern

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, Dan


    The thermal use of the underground for heating and cooling applications can be done with borehole heat exchangers. This work deals with the further development of the modelling of thermal transport processes inside and outside the borehole as well as with the application of the further developed models. The combination of high accuracy and short computation time is achieved by the development of three-dimensional thermal resistance and capacity models for borehole heat exchangers. Short transient transport processes can be calculated by the developed model with a considerable higher dynamic and accuracy than with known models from literature. The model is used to evaluate measurement data of a thermal response test by parameter estimation technique with a transient three-dimensional model for the first time. Clear advantages like shortening of the test duration are shown. The developed borehole heat exchanger model is combined with a three-dimensional description of the underground in the Finite-Element-Program FEFLOW. The influence of moving groundwater on borehole heat exchangers and borehole thermal energy stores is then quantified.

  9. Review of geoscientific data of relevance to disposal of spent nuclear fuel in deep boreholes in crystalline rock

    Energy Technology Data Exchange (ETDEWEB)

    Marsic, Nico; Grundfelt, Bertil [Kemakta Konsult AB, Stockholm (Sweden)


    In this report a compilation of recent geoscientific data of relevance to disposal of spent nuclear fuel in deep boreholes in Sweden is presented. The goal of the study has been limited to identifying and briefly describing such geoscientific information of relevance to disposal in deep boreholes that was not available at the time when previous compilations were made. Hence, the study is not to be regarded as a general up-date of new geoscientific information. Disposal of spent nuclear fuel in deep boreholes has been studied in Sweden since the second half of the 1980s. The currently studied concept has been proposed by Sandia National Laboratories in the USA. In this concept the spent fuel elements are encapsulated in cylindrical steel canisters that are joined together in strings of 40 canisters and lowered into five kilometres deep boreholes. Ten such strings are stacked between three and five kilometres depth separated from each other by concrete plugs. The study started with a review of boreholes that have been reported after the previous reviews that were published in 1998 and 2004. A total of 12 boreholes of potential relevance were identified. Further study showed that only four out of these holes penetrated into crystalline rock. Two of these were deemed to be less relevant because they were drilled in areas with much higher geothermal gradient than in the parts of the Fennoscandian shield that realistically could host a Swedish deep borehole repository. Of the two remaining boreholes, only one, a geoscientific hole drilled at Outokumpu in Finland, is associated with a reasonably complete geoscientific data set. It is worth mentioning that a large part of this hole is drilled through meta sedimentary rock (mica schist) rather than granitic rock. The information collected and reviewed has been gathered under the headings hydraulic conditions, geothermal conditions, hydrogeochemical conditions, bacteriological activity and rock mechanical properties. Only

  10. Integrating geophysical and hydrochemical borehole-log measurements to characterize the Chalk aquifer, Berkshire, United Kingdom (United States)

    Schürch, Marc; Buckley, David


    Geophysical and hydrochemical borehole-logging techniques were integrated to characterize hydraulic and hydrogeochemical properties of the Chalk aquifer at boreholes in Berkshire, UK. The down-hole measurements were made to locate fissures in the chalk, their spatial extent between boreholes, and to determine the groundwater chemical quality of the water-bearing layers. The geophysical borehole logging methods used were caliper, focused resistivity, induction resistivity, gamma ray, fluid temperature, fluid electrical conductivity, impeller and heat-pulse flowmeter, together with borehole wall optical-imaging. A multiparameter data transmitter was used to measure groundwater temperature, electrical conductivity, dissolved oxygen, pH, and redox potential of the borehole fluid down-hole. High permeability developed at the Chalk Rock by groundwater circulation provides the major flow horizon at the Banterwick Barn study site and represents a conduit system that serves as an effective local hydraulic connection between the boreholes. The Chalk Rock includes several lithified solution-ridden layers, hardgrounds, which imply a gap in sedimentation possibly representing an unconformity. Lower groundwater temperature, high dissolved-oxygen content, and flowmeter evidence of preferential groundwater flow in the Chalk Rock indicated rapid groundwater circulation along this horizon. By repeating the logging at different times of the year under changing hydraulic conditions, other water-inflow horizons within the Chalk aquifer were recognized. Résumé. Des techniques géophysiques et hydrochimiques de diagraphies en forage ont été mises en oeuvre pour caractériser les propriétés hydrauliques et hydrogéochimiques de l'aquifère de la craie dans des forages du Berkshire (Grande-Bretagne). Les mesures en descente ont été faites pour localiser les fissures dans la craie et leur développement spatial entre forages, et pour déterminer la qualité de l'eau souterraine des

  11. Investigating Seismic Wave Scattering in Heterogeneous Environments and Implications for Seismic Imaging (United States)

    Bongajum, Emmanuel Leinyuy


    ) can be used to infer structural heterogeneity and velocity distribution beyond borehole locations. However, the success of imaging with transmitted waves is subject to the influence of geology which must factor in the choice of acquisition geometry. For the first time, multivariate and multidimensional (3D) heterogeneous earth models that are conditioned by hard data from multiple boreholes are constructed. The methodology requires having at least one physical rock property attribute that is sampled along the whole borehole length. This approach helped to characterize the uncertainty in the distribution of rock densities and metal content in a study region of the Nash Creek property. The density data suggests the sulfides are disseminated and this poses challenges for both gravity and seismic imaging methods. Modeling studies suggest seismic methods will not be suited for imaging zones with such disseminated mineralization. On the other hand, when dealing with massive sulfide mineralization that has complex geology (steep dip) like the case in Thompson, the success of the seismic imaging process relies very much on the acquisition geometry as well as the variability of the physical properties of the host rock. Elastic modeling results show that a Vertical Seismic Profiling (VSP) geometry is better suited to capture the down-dip scattered wavefield from the orebody. While surface acquisition geometry with sufficient extended length in the down dip direction can also be used to detect the dipping orebody, its efficiency can however be undermined by background heterogeneity: when the scale length along the direction of dip is comparable to the dimensions of the orebody, the scattered wavefields are strong enough to mask the diffraction hyperbola generated from the ore. Moreover, the study also corroborates that converted waves generated from the scattering processes hold promise as an imaging tool for a dipping orebody as they are least affected by the scattering

  12. What can we learn from ultrasonic velocities monitoring during hydraulic fracturing of tight shale ? (United States)

    Fortin, Jérôme; Stanchits, Sergei


    Methods of prediction the size and aperture of created hydraulic fracture are essential for a proper design of unconventional reservoir well stimulation. Several theoretical models describing hydraulic fracture propagation have been developed. However, there is a lack of direct field measurements of hydraulic fracture dimensions, verifying results of these models. Monitoring of elastic wave parameters may be a useful tool to estimate fracture dimensions. Indeed, the elastic wave velocity in a medium containing a fracture is sensitive to the fracture geometry and its conditions: dry fracture or saturated with fluid. In this paper, we focus on ultrasonic velocities monitoring during hydraulic fracturing of tight shale. We report the results of hydraulic fracturing of Niobrara shale outcrop block of 279 x 279 x 381 mm size from Colorado, USA. In this experiment, the block was loaded in a polyaxial loading frame made by TerraTek, a Schlumberger Company. Stresses were applied to the rock blocks independently in three directions using flat jacks. Then viscous fluid was injected into borehole at a constant flow rate. 20 PZT sensors were embedded into pockets drilled in the rock. They were used for registration of Acoustic Emission (AE) signals and for periodical ultrasonic transmissions to measure P-wave velocities in different directions. Our results show that ultrasonic measurements can be useful for understanding the mechanics of the crack growth. More precisely, from the evolution of the P-velocities and their amplitudes during the loading, we are able: (i) to estimate the velocity of the hydraulic fracture which was found to be 0.15 mm/s (that is close to the fracture velocity inferred from the dynamic of AE spatial evolution). (ii) In addition, the evolution of the P-velocities during the loading shows that a liquid-free crack always precedes the liquid front. In our experiment, the lag is estimated to be 15 mm. (iii) Finally, at fixed distances from the borehole

  13. Geodynamic Evolution of Northeastern Tunisia During the Maastrichtian-Paleocene Time: Insights from Integrated Seismic Stratigraphic Analysis (United States)

    Abidi, Oussama; Inoubli, Mohamed Hédi; Sebei, Kawthar; Amiri, Adnen; Boussiga, Haifa; Nasr, Imen Hamdi; Salem, Abdelhamid Ben; Elabed, Mahmoud


    The Maastrichtian-Paleocene El Haria formation was studied and defined in Tunisia on the basis of outcrops and borehole data; few studies were interested in its three-dimensional extent. In this paper, the El Haria formation is reviewed in the context of a tectono-stratigraphic interval using an integrated seismic stratigraphic analysis based on borehole lithology logs, electrical well logging, well shots, vertical seismic profiles and post-stack surface data. Seismic analysis benefits from appropriate calibration with borehole data, conventional interpretation, velocity mapping, seismic attributes and post-stack model-based inversion. The applied methodology proved to be powerful for charactering the marly Maastrichtian-Paleocene interval of the El Haria formation. Migrated seismic sections together with borehole measurements are used to detail the three-dimensional changes in thickness, facies and depositional environment in the Cap Bon and Gulf of Hammamet regions during the Maastrichtian-Paleocene time. Furthermore, dating based on their microfossil content divulges local and multiple internal hiatuses within the El Haria formation which are related to the geodynamic evolution of the depositional floor since the Campanian stage. Interpreted seismic sections display concordance, unconformities, pinchouts, sedimentary gaps, incised valleys and syn-sedimentary normal faulting. Based on the seismic reflection geometry and terminations, seven sequences are delineated. These sequences are related to base-level changes as the combination of depositional floor paleo-topography, tectonic forces, subsidence and the developed accommodation space. These factors controlled the occurrence of the various parts of the Maastrichtian-Paleocene interval. Detailed examinations of these deposits together with the analysis of the structural deformation at different time periods allowed us to obtain a better understanding of the sediment architecture in depth and the delineation of

  14. Seismic Observations in the Taipei Metropolitan Area Using the Downhole Network

    Directory of Open Access Journals (Sweden)

    Win-Gee Huang


    Full Text Available Underlain by soft soils, the Taipei Metropolitan Area (TMA experienced major damage due to ground-motion amplification during the Hualien earthquake of 1986, the Chi-Chi earthquake of 1999, the Hualien earthquake of 2002 and the Taitung earthquake of 2003. To study how a local site can substantially change the characteristics of seismic waves as they pass through soft deposits below the free surface, two complementary downhole seismic arrays have been operated in the TMA, since 1991 and 2008. The accelerometer downhole array is composed of eight boreholes at depths in excess of 300 meters. The downhole array velocity sensor collocated with accelerometer composed of four boreholes at depths up to 90 meters. The integrated seismic network monitors potential earthquakes originating from faults in and around the TMA and provides wide-dynamic range measurement of data ranging in amplitude from seismic background noise levels to damage levels as a result of shaking. The data sets can be used to address on the response of soft-soil deposits to ground motions. One of the major considerations is the nonlinear response of soft soil deposits at different levels of excitation. The collocated acceloerometer and velocity sensors at boreholes give the necessary data for studies of non-linearity to be acquired. Such measurements in anticipation of future large, damaging earthquakes will be of special importance for the mitigation of earthquake losses.

  15. Seismic microzonation of Mashhad city, northeast Iran

    Directory of Open Access Journals (Sweden)

    Gholam Reza Lashkaripour


    Full Text Available Mashhad city has a substantial risk of earthquakes due to the potential of the underlying soft soils to amplify ground motions. It is therefore imperative to conduct detailed seismic hazard assessment of the area (seismic microzonation. Seismic microzonation of big cities, like Mashhad, provides a basis for site-specific hazard analysis. In the present study, microtremor observations were carried out at 90 sites in the east part of Mashhad city. The predominant frequency and spectral ratio amplitude of the ground were determined by the Nakamura technique, and a microzonation map was developed for Mashhad on the basis of the variations of the predominant frequency and spectral ratio amplitude of the ground. Soil texture and N-value standard-penetration-test (N-SPT maps and sections were prepared for different depths below the city, by analysis and interpolation of data collected in the study area from 169 boreholes. Then the predominant frequency variations were compared with soil texture and N-SPT variations for four sections in different directions in the study area. This comparison shows that with decreasing soil softening and N-SPT values, the soil predominant frequency also decreases.

  16. Hydraulic fracturing in granite under geothermal conditions (United States)

    Solberg, P.; Lockner, D.; Byerlee, J.D.


    The experimental hydraulic fracturing of granite under geothermal conditions produces tensile fracture at rapid fluid injection rates and shear fracture at slow injection rates and elevated differential stress levels. A sudden burst of acoustic emission activity accompanies tensile fracture formation whereas the acoustic emission rate increases exponentially prior to shear fracture. Temperature does not significantly affect the failure mechanism, and the experimental results have not demonstrated the occurrence of thermal fracturing. A critical result of these experiments is that fluid injection at intermediate rates and elevated differential stress levels increases permeability by more than an order of magnitude without producing macroscopic fractures, and low-level acoustic emission activity occurs simultaneously near the borehole and propagates outward into the specimen with time. Permeability measurements conducted at atmospheric pressure both before and after these experiments show that increased permeability is produced by permanent structural changes in the rock. Although results of this study have not demonstrated the occurrence of thermal fracturing, they suggest that fluid injection at certain rates in situ may markedly increase local permeability. This could prove critical to increasing the efficiency of heat exchange for geothermal energy extraction from hot dry rock. ?? 1980.

  17. Structural and hydraulic properties of a small fault zone in a layered reservoir

    Directory of Open Access Journals (Sweden)

    Jeanne P.


    Full Text Available This paper focuses on a small fault zone (too small to be detected by geophysical imaging affecting a carbonate reservoir composed of porous and low-porous layers. In a gallery located at 250-m depth in the Underground Low Noise Laboratory, hydraulic properties of a 20-m thick section of the reservoir affected by the studied fault are characterized by structural measurements and by a hydraulic injection in boreholes. Main result is that the damage zone displays contrasted permeability values (up to two orders of magnitude inherited from the differential alteration of the intact rock layers. To characterize the impact of these hydraulic properties variations on the flow of fluids, numerical simulations of supercritical CO2 injections were performed with the TOUGH2 code. It appears, the permeability variations inside the fault zone favor the appearance of high fluid overpressure located in the layers having the highest permeability and storativity.

  18. Poroelastic response of geothermal reservoirs during hydraulic stimulation treatment (United States)

    Jacquey, Antoine; Urpi, Luca; Cacace, Mauro; Blöcher, Guido; Zimmermann, Günter; Scheck-Wenderoth, Magdalena


    Enhanced geothermal systems (EGS) are engineered reservoirs developed to extract heat from low permeability and low porosity geological formations. Cyclic hydraulic stimulation treatments are used in such a context to create hydraulic fractures, minimizing the fluid injected volume (recently proposed as a mitigation strategy for induced seismicity) to gain access to the target formation fluids, drain the geothermal fluid and therefore increase the overall productivity of the geothermal reservoir. During these operations, successive cycles of injection of high flow rates are conducted to decrease the effective minimum principal stress, and therefore the tensile strength of the material, developing a hydraulic fracture. Opening of these newly developed fractures induces an additional deformation of the reservoir rocks. In this study, the poroelastic response resulting from induced deformation during cyclic hydraulic stimulation treatment of a well is investigated using hydromechanical coupling between pore pressure variations and solid rock deformation. The effects of this poroelastic response on the hydromechanical state of a reservoir is illustrated by means of field measurements of a cyclic hydraulic stimulation treatment conducted at the Groß Schönebeck geothermal research site in August 2007. This study points out that a nonlinear pore pressure response arises within the reservoir rocks due to the deformation generated by the stimulation treatment. It is shown here that the 3D poroelastic response of the reservoir leads to an unexpected quasi-instantaneous pore pressure increase in a neighbor monitoring well located approximatively 475 m away from the stimulated well at reservoir depth.

  19. Integrated seismic analysis of the Chalk Group in eastern Denmark—Implications for estimates of maximum palaeo-burial in southwest Scandinavia

    DEFF Research Database (Denmark)

    Nielsen, Lars; Boldreel, Lars Ole; Hansen, Thomas Mejer


    The origin of the topography of southwest Scandinavia is subject to discussion. Analysis of borehole seismic velocity has formed the basis for interpretation of several hundred metres of Neogene uplift in parts of Denmark.Here, refraction seismic data constrain a 7.5km long P-wave velocity model...... Group. The sonic velocities are consistent with the overall seismic layering, although they show additional fine-scale layering. Integration of gamma and sonic log with porosity data shows that seismic velocity is sensitive to clay content. In intervals near boundaries of the refraction model, moderate...

  20. Numerical sensitivity test of three-electrode laterolog borehole tool (United States)

    Szijártó, Márk; Balázs, László; Drahos, Dezső; Galsa, Attila


    Finite element numerical simulation has been carried out to investigate quantitatively the response of the three-electrode laterolog borehole tool (LL3) on radial and vertical heterogeneity of the rock. In order to calculate the apparent resistivity from the electric potential and the current discharge of the measurement electrode the probe coefficient of the LL3 tool with finite electrode extent was determined. Two independent methods, a finite element modeling and a semi-analytical solution, resulted in the probe coefficient of approx. 0.15 m with a relative deviation of 2.4% due to the different geometry, resolution and electronics of the models. It was established that LL3 is only slightly sensitive to the presence of mud when the borehole diameter is d ≤ 30 cm and the ratio of the resistivity of rock and the borehole mud is 1 ≤ R t/ R m ≤ 1000. Vertical heterogeneity test pointed out that the layer boundaries can be localized exactly even for thin bedded layer (with a thickness of 1 m) and the presence of low-resistive borehole mud. Correction factors were suggested to decrease the biasing effect of the low-resistive borehole mud and the shoulder beds on the apparent resistivity observed by LL3. Finally, it was verified that the probe has large penetration depth with excellent vertical resolution, what explains the enduring popularity of the LL3 tool in well logging.

  1. Characterization Efforts in a Deep Borehole Field Test (United States)

    Kuhlman, K. L.; Sassani, D.; Freeze, G. A.; Hardin, E. L.; Brady, P. V.


    The US Department of Energy Office of Nuclear Energy is embarking on a Deep Borehole Field Test to investigate the feasibility of constructing and characterizing two boreholes in crystalline basement rock to a depth of 5 km (16,400 ft). The concept of deep borehole disposal for radioactive waste has some advantages, including incremental construction and loading and the enhanced natural barriers provided by deep continental crystalline basement. Site characterization activities will include geomechanical (i.e., hydrofracture stress measurements), geological (i.e., core and mud logging), hydrological (i.e., packer-based pulse and pumping tests), and chemical (i.e., fluids sampled in situ from packer intervals and extracted from cores) tests. Borehole-based characterization will be used to determine the variability of system state (i.e., stress, pressure, temperature, and chemistry) with depth and interpretation of material and system parameters relevant to numerical site simulation. We explore the effects fluid density and geothermal temperature gradients (i.e., thermohaline convection) have on characterization goals in light of expected downhole conditions, including a disturbed rock zone surrounding the borehole. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the US Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

  2. Deep Borehole Field Test Requirements and Controlled Assumptions.

    Energy Technology Data Exchange (ETDEWEB)

    Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This document presents design requirements and controlled assumptions intended for use in the engineering development and testing of: 1) prototype packages for radioactive waste disposal in deep boreholes; 2) a waste package surface handling system; and 3) a subsurface system for emplacing and retrieving packages in deep boreholes. Engineering development and testing is being performed as part of the Deep Borehole Field Test (DBFT; SNL 2014a). This document presents parallel sets of requirements for a waste disposal system and for the DBFT, showing the close relationship. In addition to design, it will also inform planning for drilling, construction, and scientific characterization activities for the DBFT. The information presented here follows typical preparations for engineering design. It includes functional and operating requirements for handling and emplacement/retrieval equipment, waste package design and emplacement requirements, borehole construction requirements, sealing requirements, and performance criteria. Assumptions are included where they could impact engineering design. Design solutions are avoided in the requirements discussion. Deep Borehole Field Test Requirements and Controlled Assumptions July 21, 2015 iv ACKNOWLEDGEMENTS This set of requirements and assumptions has benefited greatly from reviews by Gordon Appel, Geoff Freeze, Kris Kuhlman, Bob MacKinnon, Steve Pye, David Sassani, Dave Sevougian, and Jiann Su.

  3. Characterization of Hydraulically Significant Discontinuities in Mudrocks at the Waste Control Specialists (WCS) Site, West Texas (United States)

    Kuszmaul, J. S.; Holt, R. M.; Powers, D. W.; Beauheim, R.; Pickens, J. F.; grisak, G. E.; Hughes, E.; Cook, S.


    that showed staining (a possible indicator of past or present hydraulic activity) are rare, vertical to near-vertical, and occur mainly in, and adjacent to, mechanically stiff siltstone and sandstone interbeds. No interconnected fracture networks were observed. A series of pressurized air tests were conducted to evaluate fracture interconnectivity at and below the landfill facilities. Three pairs of vertical and three pairs of inclined boreholes were tested at depths ranging from 40 to 215 feet below ground surface. Borehole packers and volume-displacement tools were placed in each borehole to isolate the injection and observation horizons and minimize borehole storage effects, respectively. Injection pressures ranged from 1 to 5 psig. Pressures within the injection boreholes quickly stabilized and slowly decayed due to porous media flow, while no pressure changes occurred in the observation boreholes. These tests confirm the absence of hydrologically significant fracture networks in the subsurface at the WCS site.

  4. Hydraulically actuated artificial muscles (United States)

    Meller, M. A.; Tiwari, R.; Wajcs, K. B.; Moses, C.; Reveles, I.; Garcia, E.


    Hydraulic Artificial Muscles (HAMs) consisting of a polymer tube constrained by a nylon mesh are presented in this paper. Despite the actuation mechanism being similar to its popular counterpart, which are pneumatically actuated (PAM), HAMs have not been studied in depth. HAMs offer the advantage of compliance, large force to weight ratio, low maintenance, and low cost over traditional hydraulic cylinders. Muscle characterization for isometric and isobaric tests are discussed and compared to PAMs. A model incorporating the effect of mesh angle and friction have also been developed. In addition, differential swelling of the muscle on actuation has also been included in the model. An application of lab fabricated HAMs for a meso-scale robotic system is also presented.

  5. Remotely Adjustable Hydraulic Pump (United States)

    Kouns, H. H.; Gardner, L. D.


    Outlet pressure adjusted to match varying loads. Electrohydraulic servo has positioned sleeve in leftmost position, adjusting outlet pressure to maximum value. Sleeve in equilibrium position, with control land covering control port. For lowest pressure setting, sleeve shifted toward right by increased pressure on sleeve shoulder from servovalve. Pump used in aircraft and robots, where hydraulic actuators repeatedly turned on and off, changing pump load frequently and over wide range.

  6. The hydraulic windmill (United States)

    Browing, J. A.


    An hydraulic windmill is described. It pumps pressurized oil from rotor shaft level to the ground where a motor generator produces electricity. Alternatively, the useful output may be heat. Rotor speed is governed by a flow valve. Over pressure, the result of high wind velocity, rotates the tail to move the rotor blades out-of-the-wind. Loss of oil pressure causes a brake to close as well as to swing the tail to its maximum distance from the rotor plane.

  7. Seismic techniques in coal mining

    Energy Technology Data Exchange (ETDEWEB)

    Bhattacharyya, A.K.; Belleza, G.V.


    This report describes a study of the peripheral fractured zones in coal pillars by the seismic refraction method and a version of the uphole method. The study, conducted at three collieries in New South Wales, investigated the depths of such fractured zones and the degrees of fracturing therein. The equipment consisted of a sledgehammer, 3-component borehole geophone assemblies, and a 12-channel oscillographic recorder with the facility of stacking multiple repetitions of given signals. The application of the refraction method was more complicated than the uphole method. However, the refraction method provided the depths of a fracture zone along the length of the spread, as opposed to the depth at a single location by the uphole method. The depths of the fractured zones obtained from the refraction method were less than the corresponding ones from the uphole method, the latter being closer to the findings of other investigators. The determined depths of the fractured zones in pillars were less than those in continuous ribsides. The depths of fractured zones and the degree of fracturing therein seemed to have some relationship with the depth of the seam from the surface.

  8. Dual hydraulic behaviour of the Chalk in the Netherlands North Sea

    NARCIS (Netherlands)

    Verweij, H.


    Information on the sedimentary development, seismic stratigraphy and burial compaction of the Chalk Group in the Netherlands North Sea was combined with pressure data and basin modelling to investigate the hydraulic behaviour of the Chalk Group in the Central Graben and Schill Grund High. The

  9. Undular Hydraulic Jump

    Directory of Open Access Journals (Sweden)

    Oscar Castro-Orgaz


    Full Text Available The transition from subcritical to supercritical flow when the inflow Froude number Fo is close to unity appears in the form of steady state waves called undular hydraulic jump. The characterization of the undular hydraulic jump is complex due to the existence of a non-hydrostatic pressure distribution that invalidates the gradually-varied flow theory, and supercritical shock waves. The objective of this work is to present a mathematical model for the undular hydraulic jump obtained from an approximate integration of the Reynolds equations for turbulent flow assuming that the Reynolds number R is high. Simple analytical solutions are presented to reveal the physics of the theory, and a numerical model is used to integrate the complete equations. The limit of application of the theory is discussed using a wave breaking condition for the inception of a surface roller. The validity of the mathematical predictions is critically assessed using physical data, thereby revealing aspects on which more research is needed

  10. Field determination of the three dimensional hydraulic conductivity tensor of anisotropic media: 1. Theory (United States)

    Hsieh, Paul A.; Neuman, Shlomo P.


    A field method is proposed for determining the three-dimensional hydraulic conductivity tensor and specific storage of an anisotropic porous or fractured medium. The method, known as cross-hole testing (to distinguish it from conventional single-hole packer tests), consists of injecting fluid into (or withdrawing fluid from) packed-off intervals in a number of boreholes and monitoring the transient head response in similar intervals in neighboring boreholes. The directions of the principal hydraulic conductivities need not be known prior to the test, and the boreholes may have arbitrary orientations (e.g., they can all be vertical). An important aspect of the proposed method is that it provides direct field information on whether it is proper to regard the medium as being uniform and anisotropic on the scale of the test. The first paper presents theoretical expressions describing transient and steady state head response in monitoring intervals of arbitrary lengths and orientations, to constant-rate injection into (or withdrawal from) intervals having similar or different lengths and orientations. The conditions under which these intervals can be treated mathematically as points are investigated by an asymptotic analysis. The effect of planar no-flow and constant-head boundaries on the response is analyzed by the theory of images. The second paper describes the field methodology and shows how the proposed approach works in the case of fractured granitic rocks.

  11. Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada (United States)

    Lane, J.W.; Joesten, P.K.; Pohll, G.M.; Mihevic, Todd


    Single-hole borehole-radar reflection logs were collected and interpreted in support of a study to characterize ground-water flow and transport at the Project Shoal Area (PSA) in Churchill County, Nevada. Radar logging was conducted in six boreholes using 60-MHz omni-directional electric-dipole antennas and a 60-MHz magnetic-dipole directional receiving antenna.Radar data from five boreholes were interpreted to identify the location, orientation, estimated length, and spatial continuity of planar reflectors present in the logs. The overall quality of the radar data is marginal and ranges from very poor to good. Twenty-seven reflectors were interpreted from the directional radar reflection logs. Although the range of orientation interpreted for the reflectors is large, a significant number of reflectors strike northeast-southwest and east-west to slightly northwest-southeast. Reflectors are moderate to steeply dipping and reflector length ranged from less than 7 m to more than 133 m.Qualitative scores were assigned to each reflector to provide a sense of the spatial continuity of the reflector and the characteristics of the field data relative to an ideal planar reflector (orientation score). The overall orientation scores are low, which reflects the general data quality, but also indicates that the properties of most reflectors depart from the ideal planar case. The low scores are consistent with reflections from fracture zones that contain numerous, closely spaced, sub-parallel fractures.Interpretation of borehole-radar direct-wave velocity and amplitude logs identified several characteristics of the logged boreholes: (1) low-velocity zones correlate with decreased direct-wave amplitude, indicating the presence of fracture zones; (2) direct-wave amplitude increases with depth in three of the boreholes, suggesting an increase in electrical resistivity with depth resulting from changes in mineral assemblage or from a decrease in the specific conductance of ground

  12. A regularity-based modeling of oil borehole logs (United States)

    Gaci, Said; Zaourar, Naima


    Multifractional Brownian motions (mBms) are successfully used to describe borehole logs behavior. These local fractal models allow to investigate the depth-evolution of regularity of the logs, quantified by the Hölder exponent (H). In this study, a regularity analysis is carried out on datasets recorded in Algerian oil boreholes located in different geological settings. The obtained regularity profiles show a clear correlation with lithology. Each lithological discontinuity corresponds to a jump in H value. Moreover, for a given borehole, all the regularity logs are significantly correlated and lead to similar lithological segmentations. Therefore, the Hölderian regularity is a robust property which can be used to characterize lithological heterogeneities. However, this study does not draw any relation between the recorded physical property and its estimated regularity degree for all the analyzed logs. Keywords: well logs, regularity, Hölder exponent, multifractional Brownian motion

  13. Rock Melt Borehole Sealing System, Final Technical Report for SBIR Phase I Grant No. DE-SC0011888

    Energy Technology Data Exchange (ETDEWEB)

    Osnes, John D. [RE/SPEC Inc., Argonne, IL (United States); Vining, Cody A. [RE/SPEC Inc., Argonne, IL (United States); Nopola, Jay R. [RE/SPEC Inc., Argonne, IL (United States); Roggenthen, William M. [South Dakota School of Mines & Technology, Rapid City, SD (United States)


    Purpose of Research Deep borehole disposal is one option that has received attention in recent years as a possible strategy for long-term disposal of the tens of thousands of tons of spent nuclear fuel. The feasibility of the deep borehole option relies upon designing and constructing an effective seal within the borehole to ensure that the waste package does not communicate with the shallow subsurface biosphere through the borehole itself. Some of the uncertainty associated with the long-term suitability of the deep borehole option is related to (1) the degradation of traditional sealing materials over time and (2) the inability of traditional sealing methods to adequately seal a Disturbed Rock Zone surrounding the borehole. One possible system to address these concerns consists of encapsulating the waste in a melt generated from either the waste itself or a plug above the waste. This current project expanded on previous work to further advance the deep borehole disposal concept. Research Objectives & Findings The overarching objective of the study was to evaluate the feasibility of constructing a downhole heater that is capable of meeting the technical and logistical requirements to melt rock. This ultimate objective was accomplished by two primary approaches. The first approach was to define the heater requirements and conceptually design a system that is capable of melting rock. The second approach was to determine the feasibility of conducting an in situ, field-scale melting experiment to validate the suitability of the rock melt seal concept. The evaluation and conceptual design of the heater system resulted in the following primary findings: • Borehole wall temperatures capable of producing a partial melt are achievable under most expected thermal conductivities with a 12-kilowatt heater. • Commercially available components have been identified that meet the requirements of the heater system, including resistive elements that are capable of providing the

  14. Muon borehole detector development for use in four-dimensional tomographic density monitoring (United States)

    Flygare, Joshua

    The increase of CO2 concentrations in the atmosphere and the correlated temperature rise has initiated research into methods of carbon sequestration. One promising possibility is to store CO2 in subsurface reservoirs of porous rock. After injection, the monitoring of the injected CO2 is of paramount importance because the CO2 plume, if escaped, poses health and environmental risks. Traditionally, seismic reflection methods are the chosen method of determining changes in the reservoir density due to CO2 injection, but this is expensive and not continuous. A potential and promising alternative is to use cosmic muon tomography to determine density changes in the reservoir over a period of time. The work I have completed was the development of a muon detector that will be capable of being deployed in boreholes and perform long-term tomography of the reservoir of interest. The detector has the required dimensions, an angular resolution of approximately 2 degrees, and is robust enough to survive the caustic nature of the fluids in boreholes, as well as temperature and pressure fluctuations. The detector design is based on polystyrene scintillating rods arrayed in alternating layers. The layers, as arranged, can provide four-dimensional (4D) tomographic data to detect small changes in density at depths up to approximately 2 kilometers. Geant4, a Monte Carlo simulation code, was used to develop and optimize the detector design. Additionally, I developed a method of determining the muon flux at depth, including CO2 saturation changes in subsurface reservoirs. Preliminary experiments were performed at Pacific Northwest National Laboratory. This thesis will show the simulations I performed to determine the angular resolution and background discrimination required of the detector, the experiments to determine light transport through the polystyrene scintillating rods and fibers, and the method developed to predict muon flux changes at depth expected after injection.

  15. Deep borehole disposal of high-level radioactive waste.

    Energy Technology Data Exchange (ETDEWEB)

    Stein, Joshua S.; Freeze, Geoffrey A.; Brady, Patrick Vane; Swift, Peter N.; Rechard, Robert Paul; Arnold, Bill Walter; Kanney, Joseph F.; Bauer, Stephen J.


    Preliminary evaluation of deep borehole disposal of high-level radioactive waste and spent nuclear fuel indicates the potential for excellent long-term safety performance at costs competitive with mined repositories. Significant fluid flow through basement rock is prevented, in part, by low permeabilities, poorly connected transport pathways, and overburden self-sealing. Deep fluids also resist vertical movement because they are density stratified. Thermal hydrologic calculations estimate the thermal pulse from emplaced waste to be small (less than 20 C at 10 meters from the borehole, for less than a few hundred years), and to result in maximum total vertical fluid movement of {approx}100 m. Reducing conditions will sharply limit solubilities of most dose-critical radionuclides at depth, and high ionic strengths of deep fluids will prevent colloidal transport. For the bounding analysis of this report, waste is envisioned to be emplaced as fuel assemblies stacked inside drill casing that are lowered, and emplaced using off-the-shelf oilfield and geothermal drilling techniques, into the lower 1-2 km portion of a vertical borehole {approx}45 cm in diameter and 3-5 km deep, followed by borehole sealing. Deep borehole disposal of radioactive waste in the United States would require modifications to the Nuclear Waste Policy Act and to applicable regulatory standards for long-term performance set by the US Environmental Protection Agency (40 CFR part 191) and US Nuclear Regulatory Commission (10 CFR part 60). The performance analysis described here is based on the assumption that long-term standards for deep borehole disposal would be identical in the key regards to those prescribed for existing repositories (40 CFR part 197 and 10 CFR part 63).

  16. Elements of a continuous-wave borehole radar. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Caffey, T.W.H. [Sandia National Labs., Albuquerque, NM (United States). Geophysical Technology Dept.


    The theory is developed for the antenna array for a proposed continuous-wave, ground-penetrating radar for use in a borehole, and field measurements are presented. Accomplishments include the underground measurement of the transmitting beam in the azimuth plane, active azimuth-steering of the transmitting beam, and the development of a range-to-target algorithm. The excellent performance of the antenna array supports the concept of a continuous-wave borehole radar. A field-prototype should be developed for use in both geothermal zones and for the exploration and recovery of oil and gas.

  17. Reclamation report, Basalt Waste Isolation Project, boreholes 1990

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Cadoret, N.A.


    The restoration of areas disturbed activities of the Basalt Waste Isolation Project (BWIP) has been undertaken by the US Department of Energy (DOE) in fulfillment of obligations and commitments made under the National Environmental Policy Act and the Nuclear Waste Policy Act. This restoration program comprises three separate projects: borehole reclamation, Near Surface Test Facility reclamation, and Exploratory Shaft Facility reclamation. Detailed descriptions of these reclamation projects may be found in a number of previous reports. This report describes the second phase of the reclamation program for the BWIP boreholes and analyzes its success relative to the reclamation objective. 6 refs., 14 figs., 13 tabs.

  18. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design.

    Energy Technology Data Exchange (ETDEWEB)

    Cochran, John R. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Hardin, Ernest [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This report presents conceptual design information for a system to handle and emplace packages containing radioactive waste, in boreholes 16,400 ft deep or possibly deeper. Its intended use is for a design selection study that compares the costs and risks associated with two emplacement methods: drill-string and wireline emplacement. The deep borehole disposal (DBD) concept calls for siting a borehole (or array of boreholes) that penetrate crystalline basement rock to a depth below surface of about 16,400 ft (5 km). Waste packages would be emplaced in the lower 6,560 ft (2 km) of the borehole, with sealing of appropriate portions of the upper 9,840 ft (3 km). A deep borehole field test (DBFT) is planned to test and refine the DBD concept. The DBFT is a scientific and engineering experiment, conducted at full-scale, in-situ, without radioactive waste. Waste handling operations are conceptualized to begin with the onsite receipt of a purpose-built Type B shipping cask, that contains a waste package. Emplacement operations begin when the cask is upended over the borehole, locked to a receiving flange or collar. The scope of emplacement includes activities to lower waste packages to total depth, and to retrieve them back to the surface when necessary for any reason. This report describes three concepts for the handling and emplacement of the waste packages: 1) a concept proposed by Woodward-Clyde Consultants in 1983; 2) an updated version of the 1983 concept developed for the DBFT; and 3) a new concept in which individual waste packages would be lowered to depth using a wireline. The systems described here could be adapted to different waste forms, but for design of waste packaging, handling, and emplacement systems the reference waste forms are DOE-owned high- level waste including Cs/Sr capsules and bulk granular HLW from fuel processing. Handling and Emplacement Options for Deep Borehole Disposal Conceptual Design July 23, 2015 iv ACKNOWLEDGEMENTS This report has

  19. Data Communication PC/NaI-borehole probe (Hardware & Software)

    DEFF Research Database (Denmark)

    Madsen, Peter Buch

    Development of new hard- & software to a NaI borehole probe on a PC. Save data from the probe each 10'th sec, handle the data from the probe and make calculations every 10'th sec and show the results on the monitor.......Development of new hard- & software to a NaI borehole probe on a PC. Save data from the probe each 10'th sec, handle the data from the probe and make calculations every 10'th sec and show the results on the monitor....

  20. Borehole radar system for South African gold and platinum mines

    CSIR Research Space (South Africa)

    Vogt, D


    Full Text Available for South African gold and platinum mines Declan Vogt CSIR, PO Box 91230, Auckland Park, 2006 e-mail: © 2006 December Geological Society of South Africa ABSTRACT Borehole radar is an electromagnetic tool that can be applied to assist... with marker horizons. For example, the Carbon Leader is overlain by the Green Bar Shale (Schweitzer and Johnson, 1997). SOUTH AFRICAN JOURNAL OF GEOLOGY, 2006, VOLUME 109 PAGB 521-528 522 A BOREHOLE RADAR SYSTEM EOR SOUTH AFRICAN GOLD AND PLATINUM MINES a...

  1. New insights on the Karoo shale gas potential from borehole KZF-1 (Western Cape, South Africa) (United States)

    Campbell, Stuart A.; Götz, Annette E.; Montenari, Michael


    A study on world shale reserves conducted by the Energy Information Agency (EIA) in 2013 concluded that there could be as much as 390 Tcf recoverable reserves of shale gas in the southern and south-western parts of the Karoo Basin. This would make it the 8th-largest shale gas resource in the world. However, the true extent and commercial viability is still unknown, due to the lack of exploration drilling and modern 3D seismic. Within the framework of the Karoo Research Initiative (KARIN), two deep boreholes were drilled in the Eastern and Western Cape provinces of South Africa. Here we report on new core material from borehole KZF-1 (Western Cape) which intersected the Permian black shales of the Ecca Group, the Whitehill Formation being the main target formation for future shale gas production. To determine the original source potential for shale gas we investigated the sedimentary environments in which the potential source rocks formed, addressing the research question of how much sedimentary organic matter the shales contained when they originally formed. Palynofacies indicates marginal marine conditions of a stratified basin setting with low marine phytoplankton percentages (acritarchs, prasinophytes), good AOM preservation, high terrestrial input, and a high spores:bisaccates ratio (kerogen type III). Stratigraphically, a deepening-upward trend is observed. Laterally, the basin configuration seems to be much more complex than previously assumed. Furthermore, palynological data confirms the correlation of marine black shales of the Prince Albert and Whitehill formations in the southern and south-western parts of the Karoo Basin with the terrestrial coals of the Vryheid Formation in the north-eastern part of the basin. TOC values (1-6%) classify the Karoo black shales as promising shale gas resources, especially with regard to the high thermal maturity (Ro >3). The recently drilled deep boreholes in the southern and south-western Karoo Basin, the first since the

  2. Instrument Correction and Dynamic Site Profile Validation at the Central United States Seismic Observatory, New Madrid Seismic Zone (United States)

    Brengman, C.; Woolery, E. W.; Wang, Z.; Carpenter, S.


    The Central United States Seismic Observatory (CUSSO) is a vertical seismic array located in southwestern Kentucky within the New Madrid seismic zone. It is intended to describe the effects of local geology, including thick sediment overburden, on seismic-wave propagation, particularly strong-motion. The three-borehole array at CUSSO is composed of seismic sensors placed on the surface, and in the bedrock at various depths within the 585 m thick sediment overburden. The array's deep borehole provided a unique opportunity in the northern Mississippi embayment for the direct geological description and geophysical measurement of the complete late Cretaceous-Quaternary sediment column. A seven layer, intra-sediment velocity model is interpreted from the complex, inhomogeneous stratigraphy. The S- and P-wave sediment velocities range between 160 and 875 m/s and between 1000 and 2300 m/s, respectively, with bedrock velocities of 1452 and 3775 m/s, respectively. Cross-correlation and direct comparisons were used to filter out the instrument response and determine the instrument orientation, making CUSSO data ready for analysis, and making CUSSO a viable calibration site for other free-field sensors in the area. The corrected bedrock motions were numerically propagated through the CUSSO soil profile (transfer function) and compared, in terms of both peak acceleration and amplitude spectra, to the recorded surface observations. Initial observations reveal a complex spectral mix of amplification and de-amplification across the array, indicating the site effect in this deep sediment setting is not simply generated by the shallowest layers.

  3. Hydraulic System Design of Hydraulic Actuators for Large Butterfly Valves

    Directory of Open Access Journals (Sweden)

    Ye HUANG


    Full Text Available Hydraulic control systems of butterfly valves are presently valve-controlled and pump-controlled. Valve-controlled hydraulic systems have serious power loss and generate much heat during throttling. Pump-controlled hydraulic systems have no overflow or throttling losses but are limited in the speed adjustment of the variable-displacement pump, generate much noise, pollute the environment, and have motor power that does not match load requirements, resulting in low efficiency under light loads and wearing of the variable-displacement pump. To overcome these shortcomings, this article designs a closed hydraulic control system in which an AC servo motor drives a quantitative pump that controls a spiral swinging hydraulic cylinder, and analyzes and calculates the structure and parameters of a spiral swinging hydraulic cylinder. The hydraulic system adjusts the servo motor’s speed according to the requirements of the control system, and the motor power matches the power provided to components, thus eliminating the throttling loss of hydraulic circuits. The system is compact, produces a large output force, provides stable transmission, has a quick response, and is suitable as a hydraulic control system of a large butterfly valve.

  4. Robotization in Seismic Acquisition

    NARCIS (Netherlands)

    Blacquière, G.; Berkhout, A.J.


    The amount of sources and detectors in the seismic method follows "Moore’s Law of seismic data acquisition", i.e., it increases approximately by a factor of 10 every 10 years. Therefore automation is unavoidable, leading to robotization of seismic data acquisition. Recently, we introduced a new

  5. Postinjection Normal Closure of Fractures as a Mechanism for Induced Seismicity (United States)

    Ucar, E.; Berre, I.; Keilegavlen, E.


    Understanding the controlling mechanisms underlying injection-induced seismicity is important for optimizing reservoir productivity and addressing seismicity-related concerns related to hydraulic stimulation in Enhanced Geothermal Systems. Hydraulic stimulation enhances permeability through elevated pressures, which cause normal deformations and the shear slip of preexisting fractures. Previous experiments indicate that fracture deformation in the normal direction reverses as the pressure decreases, e.g., at the end of stimulation. We hypothesize that this normal closure of fractures enhances pressure propagation away from the injection region and significantly increases the potential for postinjection seismicity. To test this hypothesis, hydraulic stimulation is modeled by numerically coupling flow in the fractures and matrix, fracture deformation, and matrix deformation for a synthetic reservoir in which the flow and mechanics are strongly affected by a complex three-dimensional fracture network. The role of the normal closure of fractures is verified by comparing simulations conducted with and without the normal closure effect.

  6. Sealing of 300 mm boreholes KXTT3 and KXTT4 at Aespoe HRL. Report of Subproject 3 of Borehole sealing Project

    Energy Technology Data Exchange (ETDEWEB)

    Pusch, Roland [Drawrite AB, Lund (Sweden); Luleaa Technical Univ., Luleaa (Sweden); Ramqvist, Gunnar [Eltekno AB, Figeholm (Sweden)


    Sealing of two moderately dipping 300 mm diameter holes that had been bored from a niche adjacent to the ramp in the Aespoe URL in conjunction with earlier geohydrological investigations (TRUE Project, Winberg et al. 2000) was successfully completed in early 2010. The work was preceded by a pilot test on the ground surface for investigating if a simple version of sealing by pressing down clay pellets into clay mud is feasible. The borehole was simulated by a steel tube that was filled with smectite mud in which a cage filled with clay pellets was moved down. The experience from this experiment was that the mud used was somewhat too stiff and that strong vibration significantly reduced its viscosity but not sufficiently much. The predicted average density at water saturation was 1,780 kg/m{sup 3} (dry density 1,240 kg/m{sup 3}). The finally selected sealing method comprised casting of concrete plugs where the inflow of water was significant (up to 30 l/min), and to install precompacted blocks of smectite-rich clay where the rock was 'dry'. The finally matured clay plugs will have a density of around 2,000 kg/m{sup 3} (dry density 1,580 kg/m{sup 3}) and a hydraulic conductivity of less than E-12 m/s, which is estimated to be at least one order of magnitude lower than the bulk conductivity of the surrounding rock mass (Pusch 2008). This provides excellent sealing of all parts of the holes deeper than about 1-2 m below the tunnel floor. Groundwater flow in the rock around the clay plugs can cause some minor erosion but this effect is deemed negligible considering the coagulating effect on released clay particles by the brackish Aespoe water. Inspection of the closed upper borehole ends showed accumulation of some very dilute mineral suspension after a few days. A careful analysis of the mineral content showed that it did not contain smectite particles, hence certifying that erosion of the clay plugs in the holes had not taken place. The particles were

  7. Urban shear-wave reflection seismics: Reconstruction support by combined shallow seismic and engineering geology investigations (United States)

    Polom, U.; Guenther, A.; Arsyad, I.; Wiyono, P.; Krawczyk, C. M.


    After the big 2004 Sumatra-Andaman earthquake, the massive reconstruction activities in the Aceh province (Northern Sumatra) were promoted by the Republic of Indonesia and the Federal Ministry of Economic Cooperation and Development. The aims of the project MANGEONAD (Management of Georisk Nanggroe Aceh Darussalam). are to establish geoscientific on the ground support for a sustainable development and management of save building constructions, lifelines, infrastructure and also natural resources. Therefore, shallow shear-wave reflection seismics was applied in close combination to engineering geology investigations in the period between 2005-2009 since depth and internal structure of the Krueng Aceh River delta (mainly young alluvial sediments) were widely unknown. Due to the requirements in the densely populated Banda Aceh region, lacking also traffic infrastructure, a small and lightweight engineering seismic setup of high mobility and high subsurface resolution capability was chosen. The S-wave land streamer system with 48 channels was applied successfully together with the ELVIS vibratory source using S- and P-waves on paved roads within the city of Banda Aceh. The performance of the S-wave system enabled the detailed seismic investigation of the shallow subsurface down to 50-150 m depth generating shaking frequencies between 20 Hz to 200 Hz. This also provides depth information extending the maximum depths of boreholes and Standard Penetrometer Testings (SPT), which could only be applied to max. 20 m depth. To integrate the results gained from all three methods, and further to provide a fast statistical analysis tool for engineering use, the Information System Engineering Geology (ISEG, BGR) was developed. This geospatial information tool includes the seismic data, all borehole information, geotechnical SPT and laboratory results from samples available in the investigation area. Thereby, the geotechnical 3D analysis of the subsurface units is enabled. The

  8. Method and system for advancement of a borehole using a high power laser (United States)

    Moxley, Joel F.; Land, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Zediker, Mark S.


    There is provided a system, apparatus and methods for the laser drilling of a borehole in the earth. There is further provided with in the systems a means for delivering high power laser energy down a deep borehole, while maintaining the high power to advance such boreholes deep into the earth and at highly efficient advancement rates, a laser bottom hole assembly, and fluid directing techniques and assemblies for removing the displaced material from the borehole.

  9. Methods for enhancing the efficiency of creating a borehole using high power laser systems (United States)

    Zediker, Mark S.; Rinzler, Charles C.; Faircloth, Brian O.; Koblick, Yeshaya; Moxley, Joel F.


    Methods for utilizing 10 kW or more laser energy transmitted deep into the earth with the suppression of associated nonlinear phenomena to enhance the formation of Boreholes. Methods for the laser operations to reduce the critical path for forming a borehole in the earth. These methods can deliver high power laser energy down a deep borehole, while maintaining the high power to perform operations in such boreholes deep within the earth.

  10. The application of sedimentology in the characterization of borehole ...

    African Journals Online (AJOL)

    The drilling of a borehole into a poorly cemented and unstable reservoir/aquifer system like the Ajali and the Nanka Sands and the withdrawal of its fluids trigger movement, because unconsolidated grains and matrix materials are dislodged and entrained in the produced fluid (water, gas or oil). The undesirability of ...

  11. Evaluation of Groundwater Potentials for Borehole Drilling by ...

    African Journals Online (AJOL)


    Evaluation of Groundwater Potentials for Borehole Drilling by Integrated Geophysical. Mapping of ... drilling. Six lithologic formations were delineated which included the top soil, clay/shale, fine grained sand, coarse grained sand, fractured bedrock and fresh bedrock. ... properties, geological (composition) and fluid content.

  12. X-ray inspection for boreholes in intact trees

    NARCIS (Netherlands)

    Jansen, R.M.C.; Hemming, J.


    X-ray systems are commonly used for luggage inspection. The size of these systems is sufficient for inspection of intact trees. The first objective of this study is to determine whether such an X-ray system is able to visualise boreholes in intact trees. The present study is partly based on human

  13. Occurrence of a Severe Acute Livestock Poisoning by Borehole ...

    African Journals Online (AJOL)

    The borehole had been out of use for 3 years and after its rehabilitation, 7,000 animals died within a day after drinking the water. The most ... Initially, the animals displayed increased frequency of urination, followed by symptoms of respiratory insufficiency, comprising of dyspnea, cyanosis, rapid and weak pulse and general ...

  14. Short communication: Dairy farm borehole water quality in the ...

    African Journals Online (AJOL)

    Most dairy farm effluent is discharged onto pastures and land by irrigation and poses a risk of enriching groundwater including borehole drinking water. Nitrate, coliforms and Escherichia coli (E. coli), in particular, may cause disease in humans and animals drinking contaminated water. The aim of this study was to obtain an ...

  15. Effective borehole design in difficult crystalline rock terrain; a case ...

    African Journals Online (AJOL)

    The Ebonyi State Police Headquarters, Abakaliki is within the area underlain by the pyroclastic rocks that are generally known to have low prospect for groundwater. Yet, a borehole with sustainable yield was required to supply part of the increased population of the barracks through a newly constructed 40,000 litres ...

  16. Evaluation of Groundwater Potentials for Borehole Drilling by ...

    African Journals Online (AJOL)


    ABSTRACT: An integrated geophysical survey involving Very Low Frequency. Electromagnetic (VLF-EM) and electrical resistivity sounding was conducted at Auchi-. Southwestern Nigeria, in order to delineate the fissured zones and associated groundwater- bearing media for borehole drilling in the study area. The area is ...

  17. Development of a mobile borehole investigation software using augmented reality (United States)

    Son, J.; Lee, S.; Oh, M.; Yun, D. E.; Kim, S.; Park, H. D.


    Augmented reality (AR) is one of the most developing technologies in smartphone and IT areas. While various applications have been developed using the AR, there are a few geological applications which adopt its advantages. In this study, a smartphone application to manage boreholes using AR has been developed. The application is consisted of three major modules, an AR module, a map module and a data management module. The AR module calculates the orientation of the device and displays nearby boreholes distributed in three dimensions using the orientation. This module shows the boreholes in a transparent layer on a live camera screen so the user can find and understand the overall characteristics of the underground geology. The map module displays the boreholes on a 2D map to show their distribution and the location of the user. The database module uses SQLite library which has proper characteristics for mobile platforms, and Binary XML is adopted to enable containing additional customized data. The application is able to provide underground information in an intuitive and refined forms and to decrease time and general equipment required for geological field investigations.

  18. Elastic waves along a cylindrical borehole in a poroelastic medium ...

    Indian Academy of Sciences (India)

    The propagation of elastic waves along a cylindrical borehole filled with/without liquid and embedded in an infinite porous medium saturated by two immiscible fluids has been studied. The theory of porous media saturated by two immiscible fluids developed by Tuncay and Corapcioglu (1997) is employed. Frequency ...

  19. Contamination of boreholes water by 76 pesticides molecules in the ...

    African Journals Online (AJOL)


    Analysis campaign of underground water was done in 2010 on five boreholes water samples situated in agricultural cotton zone. ... contamination of the underground water by pesticides were those areas where the cotton faming is practiced. Keywords: Kérou ..... center, Richardson, Texas, pp.87-89. Hani K, Narcisse A, ...

  20. Comparative study of coliform contamination of public boreholes ...

    African Journals Online (AJOL)

    This study revealed that pipe borne water and borehole water samples were contaminated in Bosso, with greater contamination observed with pipe borne water. This highlights the need for continuous assessment of the quality of public water supply and intervention measures to prevent outbreak of water-borne diseases in ...

  1. Comparative Study of Coliform Contamination of Public Boreholes ...

    African Journals Online (AJOL)


    This study revealed that pipe borne water and borehole water samples were contaminated in Bosso, with greater contamination observed with pipe borne water. This highlights the need for continuous assessment of the quality of public water supply and intervention measures to prevent outbreak of water-borne diseases in ...

  2. Artificial Recharge via Boreholes Using Treated Wastewater: Possibilities and Prospects

    Directory of Open Access Journals (Sweden)

    Kostas Voudouris


    Full Text Available Interest in artificial recharge of groundwater using pretreated wastewater continues to increase, especially in semi-arid countries. After the artificial recharge and natural treatment, the water could be extracted through boreholes pumping for direct irrigation. The selection of suitable locations for artificial recharge should be based on hydrogeological conditions, economic evaluation and environmental considerations. Clogging of boreholes that are used for artificial recharge is a serious problem and requires proper planning to reduce it. This paper deals with the investigation of the possibilities and prospects of aquifer recharge via boreholes using treated wastewater. Firstly, the aquifer recharge techniques, the proposed criteria of waste and the clogging effect are presented. Secondly, the possibility of application of artificial recharge in the South-Eastern Mesaoria aquifer of Cyprus is examined. Based on hydrogeological results, artificial recharge using tertiary treated wastewater via boreholes is one of the options available for increasing the groundwater reserves of this aquifer. The recycled water will infiltrate through gravel pack, providing favorable conditions for ventilation and laminar flow due to small water flow velocity. The treatment works include the removal of the fat, oil and grease (FOG and cyanides (CN− content in order to meet the upper acceptable limits.

  3. Contamination of boreholes water by 76 pesticides molecules in the ...

    African Journals Online (AJOL)

    Analysis campaign of underground water was done in 2010 on five boreholes water samples situated in agricultural cotton zone. The obtained results showed the presence of various active matters of at least 76 residues of pesticides, especially insecticides, herbicides and fungicides, with accumulated contents which could ...

  4. Electrical resistance tomography using steel cased boreholes as electrodes (United States)

    Daily, William D.; Ramirez, Abelardo L.


    An electrical resistance tomography method using steel cased boreholes as electrodes. The method enables mapping the electrical resistivity distribution in the subsurface from measurements of electrical potential caused by electrical currents injected into an array of electrodes in the subsurface. By use of current injection and potential measurement electrodes to generate data about the subsurface resistivity distribution, which data is then used in an inverse calculation, a model of the electrical resistivity distribution can be obtained. The inverse model may be constrained by independent data to better define an inverse solution. The method utilizes pairs of electrically conductive (steel) borehole casings as current injection electrodes and as potential measurement electrodes. The greater the number of steel cased boreholes in an array, the greater the amount of data is obtained. The steel cased boreholes may be utilized for either current injection or potential measurement electrodes. The subsurface model produced by this method can be 2 or 3 dimensional in resistivity depending on the detail desired in the calculated resistivity distribution and the amount of data to constain the models.

  5. Evaluation of Thin Bed Using Resistivity Borehole and NMR Imaging ...

    African Journals Online (AJOL)

    To better characterize thin beds and maximize reservoir potential, the resistivity borehole imaging and NMR techniques were adopted in this research study. In addition, the Thomas Stieber equations using laminated sand-shale sequence were employed in calculating parameters such as sand porosity, hydrocarbon ...

  6. Canister Design for Deep Borehole Disposal of Nuclear Waste (United States)


    Mathcad code was run for an array of 110 combinations of ambient granite temperature and linear power. Microsoft Excel was used to calculate trendline...23 1.4.4 Emplacement Process ...deep borehole disposal concept. 1.4 Scope of the Problem The following sections discuss aspects which should be considered in the design process

  7. Assessment of Heavy Metal Status of Boreholes in Calabar South ...

    African Journals Online (AJOL)

    Assessment of Heavy Metal Status of Boreholes in Calabar South Local Government Area, Cross River State, Nigeria. GN Njar, AI Iwara, RA Offiong, TD Deekor. Abstract. Although, many heavy metals are necessary in small amounts for the normal development of the biological cycles, most of them become toxic at high ...

  8. Overview of Seismic Noise and it’s Relevance to Personnel Detection (United States)


    measurements of seismic noise. Geophysics Journal International 161: 303–308. Nakamura, Y. 1989. A method for dynamic characteristics estimation of... subsurface using microtremor on the ground surface . Quarterly Report of the Railway Technology Research Institute 30: 25–30. Panou, A.A., N...borehole noise than did vertical components. This was attributed to the sensitivity of surface -mounted broadband seismome- ters to local, dynamic

  9. Fluid Power/Basic Hydraulics. Instructor's Guide. (United States)

    Stanbery, Richard

    This guide is designed to assist industrial vocational instructors in teaching a course on fluid power and basic hydraulics. Covered in the unit on the basics of fluid power and hydraulics are the following topics: the fundamentals of fluid power and hydraulics, basic hydraulic circuits, and servicing a hydraulic jack. The second unit, consisting…

  10. Applied hydraulic transients

    CERN Document Server

    Chaudhry, M Hanif


    This book covers hydraulic transients in a comprehensive and systematic manner from introduction to advanced level and presents various methods of analysis for computer solution. The field of application of the book is very broad and diverse and covers areas such as hydroelectric projects, pumped storage schemes, water-supply systems, cooling-water systems, oil pipelines and industrial piping systems. Strong emphasis is given to practical applications, including several case studies, problems of applied nature, and design criteria. This will help design engineers and introduce students to real-life projects. This book also: ·         Presents modern methods of analysis suitable for computer analysis, such as the method of characteristics, explicit and implicit finite-difference methods and matrix methods ·         Includes case studies of actual projects ·         Provides extensive and complete treatment of governed hydraulic turbines ·         Presents design charts, desi...

  11. Monitoring hydraulic processes with automated time-lapse electrical resistivity tomography (ALERT) (United States)

    Kuras, Olivier; Pritchard, Jonathan D.; Meldrum, Philip I.; Chambers, Jonathan E.; Wilkinson, Paul B.; Ogilvy, Richard D.; Wealthall, Gary P.


    Hydraulic processes in porous media can be monitored in a minimally invasive fashion by time-lapse electrical resistivity tomography (ERT). The permanent installation of specifically designed ERT instrumentation, telemetry and information technology (IT) infrastructure enables automation of data collection, transfer, processing, management and interpretation. Such an approach gives rise to a dramatic increase in temporal resolution, thus providing new insight into rapidly occurring subsurface processes. In this paper, we discuss a practical implementation of automated time-lapse ERT. We present the results of a recent study in which we used controlled hydraulic experiments in two test cells at reduced field scale to explore the limiting conditions for process monitoring with cross-borehole ERT measurements. The first experiment used three adjacent boreholes to monitor rapidly rising and falling water levels. For the second experiment, we injected a saline tracer into a homogeneous flow field in freshwater-saturated sand; the dynamics of the plume were then monitored with 2D measurements across a 9-borehole fence and 3D measurements across a 3 × 3 grid of boreholes. We investigated different strategies for practical data acquisition and show that simple re-ordering of ERT measurement schemes can help harmonise data collection with the nature of the monitored process. The methodology of automated time-lapse ERT was found to perform well in different monitoring scenarios (2D/3D plus time) at time scales associated with realistic subsurface processes. The limiting factor is the finite amount of time needed for the acquisition of sufficiently comprehensive datasets. We found that, given the complexity of our monitoring scenarios, typical frame rates of at least 1.5-3 images per hour were possible without compromising image quality.

  12. The microbiological quality of wells and borehole waters in Dar es ...

    African Journals Online (AJOL)

    Toilets, septic tanks and poor construction and maintenance of wells and boreholes were identified as the possible potential sources of contamination of the well and borehole waters. The majority of the wells and boreholes were within 10 to 20m from toilets and septic tanks while the WHO guideline recommends 30m away ...

  13. Methods and apparatus for removal and control of material in laser drilling of a borehole (United States)

    Rinzler, Charles C.; Zediker, Mark S.; Faircloth, Brian O.; Moxley, Joel F.


    The removal of material from the path of a high power laser beam during down hole laser operations including drilling of a borehole and removal of displaced laser effected borehole material from the borehole during laser operations. In particular, paths, dynamics and parameters of fluid flows for use in conjunction with a laser bottom hole assembly.

  14. Borehole climatology: a discussion based on contributions from climate modeling

    Directory of Open Access Journals (Sweden)

    J. F. González-Rouco


    Full Text Available Progress in understanding climate variability through the last millennium leans on simulation and reconstruction efforts. Exercises blending both approaches present a great potential for answering questions relevant both for the simulation and reconstruction of past climate, and depend on the specific peculiarities of proxies and methods involved in climate reconstructions, as well as on the realism and limitations of model simulations. This paper explores research specifically related to paleoclimate modeling and borehole climatology as a branch of climate reconstruction that has contributed significantly to our knowledge of the low frequency climate evolution during the last five centuries.

    The text flows around three main issues that group most of the interaction between model and geothermal efforts: the use of models as a validation tool for borehole climate reconstructions; comparison of geothermal information and model simulations as a means of either model validation or inference about past climate; and implications of the degree of realism on simulating subsurface climate on estimations of future climate change.

    The use of multi-centennial simulations as a surrogate reality for past climate suggests that within the simplified reality of climate models, methods and assumptions in borehole reconstructions deliver a consistent picture of past climate evolution at long time scales. Comparison of model simulations and borehole profiles indicate that borehole temperatures are responding to past external forcing and that more realism in the development of the soil model components in climate models is desirable. Such an improved degree of realism is important for the simulation of subsurface climate and air-ground interaction; results indicate it could also be crucial for simulating the adequate energy balance within climate change scenario experiments.


    Energy Technology Data Exchange (ETDEWEB)

    Nelson, P.; Paulsson, B.; Rachiele, R.; Andersson, L.; Schrauf, T.; Hustrulid, W.; Duran, O.; Magnusson, K.A.


    Four different systems of borehole instrumentation have been employed thus far at an experimental site at Stripa, Sweden where a series of hydrological and thermo-mechanical experiments are being conducted to examine the suitability of granitic rock for the storage of radioactive waste materials. Asuite of seven logs--neutron, gamma-gamma, resistivity, gamma ray, sonic, caliper, and temperature--operated in a borehole of 380-m depth located eleven zones where the rock permeability is expected to be enhanced due to the presence of open fractures. The sonic waveform record proved especially useful in this regard. Borehole measurements were also acquired in a large number of boreholes from 5- to 14-m length located in experimental drifts some 340-m underground. Here several physical properties, including the porosity, density, sonic velocity, and borehole rugosity, are generally quite uniform, with the exception of a few local chloritic zones and a few minor fractures. However, in situ determinations of the mechanical modulus with the CSM cell indicate substantial variability, with some apparent fracture control. Uranium and thorium concentrations are quite high in the Stripa granite, with local fluctuations associated with mineralogical changes as revealed by the gamma-ray log. Adifferential resistance probe appears promising as a sensitive detector of fine fracturing. Across-hole ultrasonic system indicates variations of a few percent in compressional- and shear-wave velocities, reflecting the presence of fractures and changes in fracture characteristics as the rock is heated in a simulated storage test. The geophysical and mechanical data are being compared with the results from core and television logging, with hydrological test data on static pressure and injection permeability, and with displacements induced by thermal loading.

  16. Seismic Fracture Characterization Methodologies for Enhanced Geothermal Systems

    Energy Technology Data Exchange (ETDEWEB)

    Queen, John H. [Hi-Geophysical, Inc., Ponca, OK (United States)


    Executive Summary The overall objective of this work was the development of surface and borehole seismic methodologies using both compressional and shear waves for characterizing faults and fractures in Enhanced Geothermal Systems. We used both surface seismic and vertical seismic profile (VSP) methods. We adapted these methods to the unique conditions encountered in Enhanced Geothermal Systems (EGS) creation. These conditions include geological environments with volcanic cover, highly altered rocks, severe structure, extreme near surface velocity contrasts and lack of distinct velocity contrasts at depth. One of the objectives was the development of methods for identifying more appropriate seismic acquisition parameters for overcoming problems associated with these geological factors. Because temperatures up to 300º C are often encountered in these systems, another objective was the testing of VSP borehole tools capable of operating at depths in excess of 1,000 m and at temperatures in excess of 200º C. A final objective was the development of new processing and interpretation techniques based on scattering and time-frequency analysis, as well as the application of modern seismic migration imaging algorithms to seismic data acquired over geothermal areas. The use of surface seismic reflection data at Brady's Hot Springs was found useful in building a geological model, but only when combined with other extensive geological and geophysical data. The use of fine source and geophone spacing was critical in producing useful images. The surface seismic reflection data gave no information about the internal structure (extent, thickness and filling) of faults and fractures, and modeling suggests that they are unlikely to do so. Time-frequency analysis was applied to these data, but was not found to be significantly useful in their interpretation. Modeling does indicate that VSP and other seismic methods with sensors located at depth in wells will be the most

  17. Study of borehole probing methods to improve the ground characterization (United States)

    Naeimipour, Ali

    Collecting geological information allows for optimizing ground control measures in underground structures. This includes understanding of the joints and discontinuities and rock strength to develop rock mass classifications. An ideal approach to collect such information is through correlating the drilling data from the roofbolters to assess rock strength and void location and properties. The current instrumented roofbolters are capable of providing some information on these properties but not fully developed for accurate ground characterization. To enhance existing systems additional instrumentation and testing was conducted in laboratory and field conditions. However, to define the geology along the boreholes, the use of probing was deemed to be most efficient approach for locating joints and structures in the ground and evaluation of rock strength. Therefore, this research focuses on selection and evaluation of proper borehole probes that can offer a reliable assessment of rock mass structure and rock strength. In particular, attention was paid to borehole televiewer to characterize rock mass structures and joints and development of mechanical rock scratcher for determination of rock strength. Rock bolt boreholes are commonly drilled in the ribs and the roof of underground environments. They are often small (about 1.5 inches) and short (mostly 2-3 meter). Most of them are oriented upward and thus, mostly dry or perhaps wet but not filled with water. No suitable system is available for probing in such conditions to identify the voids/joints and specifically to measure rock strength for evaluation of rock mass and related optimization of ground support design. A preliminary scan of available borehole probes proved that the best options for evaluation of rock structure is through analysis of borehole images, captured by optical televiewers. Laboratory and field trials with showed that these systems can be used to facilitate measurement of the location, frequency and

  18. Nucleation of dynamic slip on a hydraulically fractured fault (United States)

    Azad, M.; Garagash, D. I.; Satish, M.


    This work is concerned with the relationship between hydraulic fracturing injection into a fault and the possibility of a seismic slip. The results of this study show that the nucleation of dynamic slip on a fault with slip-weakening friction is only weakly dependent on the magnitude of the stress perturbation ahead of the propagating hydraulic fracture (HF), or the HF propagation regime, and is mainly controlled by the hydraulic fracture length (i.e., the size of the fully unloaded fault segment at a given time). The growth of the fault slipping patch remains stable when the background shear stress τ0 is smaller than the residual fault strength τr under ambient conditions. Otherwise (τ0>τr), nucleation of dynamic slip takes place when the hydraulic fracture grows to the critical size ℓc, which is vanishingly small ∝τp-τ0 for critically stressed faults (i.e., when the background stress approaches the fault peak strength, τ0→τp) and is diverging as ∝1/(τ0-τr) when the stability boundary is approached (τ0→τr). Our solution for the critical HF size allows to infer the corresponding fluid injection volume that may lead to slip instability on a fault with given frictional properties and background stress.

  19. Detection of buried pipes by polarimetric borehole radar; Polarimetric borehole radar ni yoru maisetsukan no kenshutsu jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Niitsuma, H. [Tohoku University, Sendai (Japan); Nakauchi, T. [Osaka Gas Co. Ltd., Osaka (Japan)


    If the borehole radar is utilized for detection of buried pipes, the underground radar measurement becomes possible even in the situation where the mesurement on the earth surface is difficult, for example, such a place as under the road where there is much traffic. However, since buried pipes are horizontally installed and the existing borehole radar can send/receive only vertical polarization, the measurement conducted comes to be poor in efficiency from a viewpoint of the polarization utilization. Therefore, by introducing the polarimetric borehole radar to the detection of buried pipes, a basic experiment was conducted for the effective detection of horizontal buried pipes. Proposing the use of a slot antenna which can send/receive horizontal polarization in borehole in addition to a dipole antenna which sends/receives vertical polarization, developed was a step frequency type continuous wave radar of a network analyzer basis. As a result of the experiment, it was confirmed that reflection from buried pipes is largely dependent on polarization. Especially, it was found that in the slot dipole cross polarization mesurement, reflection from buried pipes can be emphasized. 4 refs., 5 figs.

  20. Application of MRF-based Stochastic Joint Inversion of Transient Hydraulic Head and Electrical Resistivity Measurements to Identify 2-D Fracture Zone Connectivity (United States)

    Zhang, G.; Oware, E. K.


    Accurate quantification of the geometric and hydraulic properties of fracture zones (FZs) and their connectivity is crucial to the management of groundwater resources. The widely used equivalent porous medium approach for representing fractured systems (FSs) is inadequate to predict fracture transport processes due to the averaging of the sharp hydraulic contrast between the matrix and the FZs. Geophysical techniques provide a viable opportunity for high-resolution imaging of spatially continuous properties of FSs in contrast to those obtainable from discrete borehole measurements. Traditional geophysical imaging strategies, however, produce smoothed-out features of the FS. Here, we apply a recently developed Markov random field (MRF)-based stochastic imaging strategy to characterize a 2-D FS. We infer, from conditional data, site-specific statistics to capture geometric features, such as orientation and clustering of regions. The calibrated spatial statistics are then employed to model the geometric configuration of the FS by treating it as a binary system comprising the matrix and the FZs. We subsequently model the hydraulic properties within the identified matrix and FZs. This two-step modeling approach enables the recovery of sharp lithological and hydraulic boundaries. We demonstrate the strategy with field-scale pumping tests (PTs) and 2-D cross-borehole electrical resistivity (ER) experiments. We pumped each well at three different pumping rates to stress the aquifer differently, resulting in a total of six PTs. Transient hydraulic heads were recorded in both wells during each PT. We performed cross-borehole ER with 0.25 m electrode spacing with circulating dipole-dipole data acquisition routine. We show, from joint inversion of the hydrogeological and ER measurements, that the strategy is able to accurately delineate non-smooth FZs and their connectivity with good correlations with FZs identified from optical borehole images from the two wells.

  1. Hydraulic rams; a comparative investigation

    NARCIS (Netherlands)

    Tacke, J.H.P.M.


    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram:

  2. Permeability in fractured rocks from deep geothermal boreholes in the Upper Rhine Graben (United States)

    Vidal, Jeanne; Whitechurch, Hubert; Genter, Albert; Schmittbuhl, Jean; Baujard, Clément


    Permeability in fractured rocks from deep geothermal boreholes in the Upper Rhine Graben Vidal J.1, Whitechurch H.1, Genter A.2, Schmittbuhl J.1, Baujard C.2 1 EOST, Université de Strasbourg 2 ES-Géothermie, Strasbourg The thermal regime of the Upper Rhine Graben (URG) is characterized by a series of geothermal anomalies on its French part near Soultz-sous-Forêts, Rittershoffen and in the surrounding area of Strasbourg. Sedimentary formations of these areas host oil field widely exploited in the past which exhibit exceptionally high temperature gradients. Thus, geothermal anomalies are superimposed to the oil fields which are interpreted as natural brine advection occurring inside a nearly vertical multi-scale fracture system cross-cutting both deep-seated Triassic sediments and Paleozoic crystalline basement. The sediments-basement interface is therefore very challenging for geothermal industry because most of the geothermal resource is trapped there within natural fractures. Several deep geothermal projects exploit local geothermal energy to use the heat or produce electricity and thus target permeable fractured rocks at this interface. In 1980, a geothermal exploration well was drilled close to Strasbourg down to the Permian sediments at 3220 m depth. Bottom hole temperature was estimated to 148°C but the natural flow rate was too low for an economic profitability (project was abandoned. The Soultz-sous-Forêts project, initiated in 1986, explored during more than 30 years the experimental geothermal site by drilling five boreholes, three of which extend to 5 km depth. They identified a temperature of 200° C at 5 km depth in the granitic basement but with a variable flow rate. Hydraulic and chemical stimulation operations were applied in order to increase the initial low permeability by reactivating and dissolving sealed fractures in basement. The productivity was considerably improved and allows geothermal exploitation at 165° C and 20 L/s. Recent studies

  3. Hydraulic Stability of Accropode Armour

    DEFF Research Database (Denmark)

    Jensen, T.; Burcharth, H. F.; Frigaard, Peter

    , and to assess the influence of core permeability on the hydraulic stability of Accropodes. Two structures were examined, one with a relatively permeable core and one with a relatively impermeable core. In November/December 1995, Ph.D.-student Marten Christensen carried out the model tests on the structure...... with permeable core (crushed granite with a gradation of 5-8 mm). The outcome of this study is described in "Hydraulic Stability of Single-Layer Dolos and Accropode Armour Layers" by Christensen & Burcharth (1995). In January/February 1996, Research Assistant Thomas Jensen carried out a similar study......The present report describes the hydraulic model tests of Accropode armour layers carried out at the Hydraulics Laboratory at Aalborg University from November 1995 through March 1996. The objective of the model tests was to investigate the hydraulic stability of Accropode armour layers...

  4. Good vibrations. [Hydraulic turbines

    Energy Technology Data Exchange (ETDEWEB)

    Reynolds, P.


    The latest developments in the Voith Turbine Control and Automation System (VTLS), which couples digital control technology to hydropower plant equipment, are described. Prominent among these is the vibration diagnostics module for hydraulic turbines. It provides machine-specific diagnostic logic for a vibration monitoring and analysis system. Of the two other VTLS modules described, the operation module optimizes the control of a power plant with three or more turbines by considering the individual properties of each in turn, recommending which should be run, and how, in order to partition the load for a required power output. The cavitation module is a diagnostic system which enables the limits of operation of the turbines to be extended to bands just outside those determined by cavitation calculations. (3 figures). (UK)

  5. Testing the Extensional Detachment Paradigm: A Borehole Observatory in the Sevier Desert Basin

    Directory of Open Access Journals (Sweden)

    Gianreto Manatschal


    Full Text Available Low-angle normal faults or detachments are widely regarded as playing an important role in crustal extension and the development of rifted continental margins (Manatschal et al., 2007. However, no consensus exists on how to resolve the mechanical paradox implied by the gentledips of these faults and by the general absence of evidence for associated seismicity (Sibson, 1985; Wernicke, 1995; Axen, 2004. As part of a new initiative to rationalize geological and geophysical evidence and our theoretical understanding of how rocks deform, a group of forty-seven scientists and drilling experts from five countries met for four days on 15–18 July 2008 to discuss the present status of the paradox and a borehole-based strategy for resolving it. The workshop was held at two venues in Utah (the Utah Department ofNatural Resources in Salt Lake City, and Solitude Mountain Resort in the adjacent Wasatch Range, with a one-day field trip to the Sevier Desert basin of west-central Utah (Figs. 1, 2 to examine the general setting of potential drill sites and the footwall geology of the Sevier Desert detachment (Canyon Range.

  6. The Explosion of March 2004 at Montserrat: Constraints From Borehole Strain Data (United States)

    Linde, A. T.; Sacks, S.; Hidayat, D.; Voight, B.; Malin, P.; Shalev, E.; Mattioli, G. S.; Young, S. R.; Elsworth, D.


    The dome-building volcano Soufriere Hills on Montserrat in the Carribean has been active since about 1995. By the end of January 2003, the CALIPSO group had established a small network of 4 borehole sites with the instrumentation including Sacks-Evertson dilatometers. Major dome collapse in July 2003, reported elsewhere, was accompanied by increased pressure in a deep (~5km) reservoir. In March 2004 a well observed and recorded explosion took place (Green and Neuberg, 2005). This event resulted in clear, coherent signals (peak amplitudes up to ~100 nanostrain) on the 3 strainmeters then being recorded. The amplitudes and polarities of the strain signals from this event cannot be satisfied by a single Mogi-like source: two closer sites at similar distances (but different azimuths) record similar amplitudes but opposite polarities while the most distant site has amplitude less than one-fifth that of the nearer sites. The data are well satisfied by a small shallow dike striking N55W, consistent with geologic fabric, together with corresponding loss of pressure in the deep reservoir. Seismic activity accompanying the explosion does not commence until some time after the onset of the strain event, i.e. after the dike begins to form. Later, the magma chamber is re-pressurized.

  7. The Montserrat Soufriere Hills Explosion of March 2004: Magma Geometry and Incompressibility From Borehole Strain Data (United States)

    Linde, A. T.; Sacks, S.; Hidayat, D.; Voight, B.


    The dome-building volcano Soufriere Hills on Montserrat in the Carribean has been active since about 1995. By the end of January 2003, the CALIPSO group had established a small network of 4 borehole sites with the instrumentation including Sacks-Evertson dilatometers. Major dome collapse in July 2003 was accompanied by increased pressure in a deep (~5km) reservoir. In March 2004 an explosion resulted in clear, coherent signals (peak amplitudes up to ~100 nanostrain) on the 3 strainmeters then being recorded. The amplitudes and polarities of the strain signals from this event cannot be satisfied by a single Mogi-like source: two closer sites at similar distances (but different azimuths) record similar amplitudes but opposite polarities while the most distant site has amplitude less than one-fifth that of the nearer sites. The data are well satisfied by a small shallow dike striking N58W, consistent with geologic fabric, together with corresponding loss of pressure in the deep reservoir. Seismic activity accompanying the explosion does not commence until some time after the onset of the strain event, i.e. after the dike begins to grow. From the strain changes at the different sites that occur before any significant surface activity, together with conservation requirements, we are able to obtain an estimate of ~7 GPa for the bulk modulus of the magma in the reservoir. This is consistent with the presence of a few percent free gas.

  8. Seismic velocity uncertainties and their effect on geothermal predictions: A case study (United States)

    Rabbel, Wolfgang; Köhn, Daniel; Bahadur Motra, Hem; Niederau, Jan; Thorwart, Martin; Wuttke, Frank; Descramble Working Group


    Geothermal exploration relies in large parts on geophysical subsurface models derived from seismic reflection profiling. These models are the framework of hydro-geothermal modeling, which further requires estimating thermal and hydraulic parameters to be attributed to the seismic strata. All petrophysical and structural properties involved in this process can be determined only with limited accuracy and thus impose uncertainties onto the resulting model predictions of temperature-depth profiles and hydraulic flow, too. In the present study we analyze sources and effects of uncertainties of the seismic velocity field, which translate directly into depth uncertainties of the hydraulically and thermally relevant horizons. Geological sources of these uncertainties are subsurface heterogeneity and seismic anisotropy, methodical sources are limitations in spread length and physical resolution. We demonstrate these effects using data of the EU-Horizon 2020 project DESCRAMBLE investigating a shallow super-critical geothermal reservoir in the Larderello area. The study is based on 2D- and 3D seismic reflection data and laboratory measurements on representative rock samples under simulated in-situ conditions. The rock samples consistently show P-wave anisotropy values of 10-20% order of magnitude. However, the uncertainty of layer depths induced by anisotropy is likely to be lower depending on the accuracy, with which the spatial orientation of bedding planes can be determined from the seismic reflection images.

  9. 3D joint inversion of gravity-gradient and borehole gravity data (United States)

    Geng, Meixia; Yang, Qingjie; Huang, Danian


    Borehole gravity is increasingly used in mineral exploration due to the advent of slim-hole gravimeters. Given the full-tensor gradiometry data available nowadays, joint inversion of surface and borehole data is a logical next step. Here, we base our inversions on cokriging, which is a geostatistical method of estimation where the error variance is minimised by applying cross-correlation between several variables. In this study, the density estimates are derived using gravity-gradient data, borehole gravity and known densities along the borehole as a secondary variable and the density as the primary variable. Cokriging is non-iterative and therefore is computationally efficient. In addition, cokriging inversion provides estimates of the error variance for each model, which allows direct assessment of the inverse model. Examples are shown involving data from a single borehole, from multiple boreholes, and combinations of borehole gravity and gravity-gradient data. The results clearly show that the depth resolution of gravity-gradient inversion can be improved significantly by including borehole data in addition to gravity-gradient data. However, the resolution of borehole data falls off rapidly as the distance between the borehole and the feature of interest increases. In the case where the borehole is far away from the target of interest, the inverted result can be improved by incorporating gravity-gradient data, especially all five independent components for inversion.

  10. Seismic Imaging and Monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Lianjie [Los Alamos National Laboratory


    I give an overview of LANL's capability in seismic imaging and monitoring. I present some seismic imaging and monitoring results, including imaging of complex structures, subsalt imaging of Gulf of Mexico, fault/fracture zone imaging for geothermal exploration at the Jemez pueblo, time-lapse imaging of a walkway vertical seismic profiling data for monitoring CO{sub 2} inject at SACROC, and microseismic event locations for monitoring CO{sub 2} injection at Aneth. These examples demonstrate LANL's high-resolution and high-fidelity seismic imaging and monitoring capabilities.

  11. Mitigating Induced Seismicity Through Active Pressure Management in Numerical Simulations (United States)

    Kroll, K.; Richards-Dinger, K. B.; White, J. A.


    The recent upturn of seismicity rates in the Central and Eastern United States and Canada has been attributed to industrial operations such as waste-water disposal, hydraulic fracturing, and subsurface carbon storage. We couple the 3D, physics-based earthquake simulator, RSQSim, to a reservoir model to investigate the space-time characteristics of earthquakes induced by pore-fluid pressure increases and/or poroelastic stresses during injection. RSQSim employs rate-state friction, which gives rise to spatiotemporal earthquake clustering. The simulator generates long catalogs of seismicity based on stress changes due to fault interaction and external stress perturbations with great computational efficiency, allowing for multiple simulations to systematically explore the parameters that control induced seismicity. These simulations provide physics-based statistical data that may contribute to the formalization of optimal injection operations designed to minimize risk of seismicity at a given industrial site. Industrial operators may modify injection rates as an active seismicity mitigation tool to either reduce the total number of earthquakes or attempt to reduce the likelihood of future large events. To explore the efficacy of this approach, we use RSQSim to explore how sequences of induced earthquakes respond to changes in injection schedule. We simulate induced seismicity on a single optimally oriented fault with fractally distributed initial shear stresses and compare results from models with/without along-strike fault permeability and poroelastic stress changes. We investigate the seismic response to several injection schedules that lie between two end-member scenarios, 1) constant injection at low rates, and 2) periodic injection at high rates. We evaluate the cumulative number of events, total seismic moment release, and the spatio-temporal characteristics of seismicity including the time/location of the next large event after adjusting injection rates

  12. Novel ionic polymeric hydraulic actuators (United States)

    Shahinpoor, Mohsen; Kim, Kwang J.


    It is now well recognized that a strip of ionic polymer- metal composite (IPMC) exhibits a spontaneous bending capability under the influence of an electric potential. A key observation is the appearance and disappearance of water on the expansion and contraction surfaces of the strip, respectively. Such water appearing/disappearing activities occur near the permeable metal electrodes. The imposition of en elctric field causes the mobile cations that are conjugated to the polymeric anions to undergo electrophoretic dynamic migration that can result in local deformation of the material. Such an electrophoretic behavior of the IPMC causes the water to leak out of the permeable electroded boundary so as to lower the actuation performance. This situation is similar to a leaking hydraulic actuator (hydraulic jack), which has the highest force density notwithstanding the compressor unit weight. Herein, a new category of actuators as ionic polymeric hydraulic actuators (IPHA's) is defined. The IPMC is a good example of such ionic polymeric hydraulic actuators. The advantage of ionic polymeric hydraulic actuators is their potential to generate substantially high force densities, theoretically better than current hydraulic actuators. Based upon this ionic polymer hydraulic actuator concept, a certain manufacturing technique was developed to increase the force density of the conventional IPMC's by a factor of two (100% improvement in force). This technology and associated experimental results are presented in this paper.

  13. Hydraulic conductivity of compacted zeolites. (United States)

    Oren, A Hakan; Ozdamar, Tuğçe


    Hydraulic conductivities of compacted zeolites were investigated as a function of compaction water content and zeolite particle size. Initially, the compaction characteristics of zeolites were determined. The compaction test results showed that maximum dry unit weight (γ(dmax)) of fine zeolite was greater than that of granular zeolites. The γ(dmax) of compacted zeolites was between 1.01 and 1.17 Mg m(-3) and optimum water content (w(opt)) was between 38% and 53%. Regardless of zeolite particle size, compacted zeolites had low γ(dmax) and high w(opt) when compared with compacted natural soils. Then, hydraulic conductivity tests were run on compacted zeolites. The hydraulic conductivity values were within the range of 2.0 × 10(-3) cm s(-1) to 1.1 × 10(-7) cm s(-1). Hydraulic conductivity of all compacted zeolites decreased almost 50 times as the water content increased. It is noteworthy that hydraulic conductivity of compacted zeolite was strongly dependent on the zeolite particle size. The hydraulic conductivity decreased almost three orders of magnitude up to 39% fine content; then, it remained almost unchanged beyond 39%. Only one report was found in the literature on the hydraulic conductivity of compacted zeolite, which is in agreement with the findings of this study.

  14. Waste isolation pilot plant (WIPP) borehole plugging program description

    Energy Technology Data Exchange (ETDEWEB)

    Christensen, C.L.; Hunter, T.O.


    The tests and experiments described attempt to provide a mix of borehole (with limited access) and in-mine (with relatively unlimited access) environments in which assessment of the various issues involved can be undertaken. The Bell Canyon Test provides the opportunity to instrument and analyze a plug in a high pressure region. The Shallow Hole Test permits application of best techniques for plugging and then access to both the top and bottom of the plug for further analysis. The Diagnostic Test Hole permits recovery of bench scale size samples for analysis and establishes an in-borehole laboratory in which to conduct testing and analysis in all strata from the surface into the salt horizon. The additional in mine experiments provide the opportunity to investigate in more detail specific effects on plugs in the salt region and allows evaluation of instrumentation systems.

  15. Development of an acoustic sensor for a geothermal Borehole Televiewer

    Energy Technology Data Exchange (ETDEWEB)

    Wonn, J.W.


    The objective of this project is to upgrade acoustic sensor technology such that appropriate well logging instruments can be made to operate under the hostile environment conditions anticipated in geothermal resource exploration and evaluation. The Borehole Televiewer (BHTV) was selected as the vehicle for this sensor improvement work, primarily because of its demonstrated ability to detect and characterize fractures under sub-geothermal conditions. The work done toward providing an improved sensor for the televiewer is described. An experimental sensor concept was devised, incorporating a thin metal acoustic window, an improved, high-temperature internal coupling fluid, and thermally resistant sensor internals. During an autoclave test, it was successfully demonstrated that the resulting experimental sensor design concept provides the basic target detection and characterization functions required of a fracture mapping, Borehole Televiewer under simulated geothermal conditions. In particular, the experimental sensor remained operational at 275/sup 0/C and 7000 psi.

  16. Deep Borehole Emplacement Mode Hazard Analysis Revision 0

    Energy Technology Data Exchange (ETDEWEB)

    Sevougian, S. David [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)


    This letter report outlines a methodology and provides resource information for the Deep Borehole Emplacement Mode Hazard Analysis (DBEMHA). The main purpose is identify the accident hazards and accident event sequences associated with the two emplacement mode options (wireline or drillstring), to outline a methodology for computing accident probabilities and frequencies, and to point to available databases on the nature and frequency of accidents typically associated with standard borehole drilling and nuclear handling operations. Risk mitigation and prevention measures, which have been incorporated into the two emplacement designs (see Cochran and Hardin 2015), are also discussed. A key intent of this report is to provide background information to brief subject matter experts involved in the Emplacement Mode Design Study. [Note: Revision 0 of this report is concentrated more on the wireline emplacement mode. It is expected that Revision 1 will contain further development of the preliminary fault and event trees for the drill string emplacement mode.

  17. Development of an acoustic sensor for a geothermal borehole televiewer

    Energy Technology Data Exchange (ETDEWEB)

    Wonn, J.W.


    The objective of this project is to upgrade acoustic sensor technology such that appropriate well logging instruments can be made to operate under the hostile environment conditions anticipated in geothermal resource exploration and evaluation. The Borehole Televiewer (BHTV) was selected as the vehicle for this sensor improvement work, primarily because of its demonstrated ability to detect and characterize fractures under sub-geothermal conditions. The work done toward providing an improved sensor for the televiewer is described. An experimental sensor concept was devised, incorporating a thin metal acoustic window, an improved, high-temperature internal coupling fluid, and thermally resistant sensor internals. During an autoclave test, it was successfully demonstrated that the resulting experimental sensor design concept provides the basic target detection and characterization functions required of a fracture mapping, Borehole Televiewer under simulated geothermal conditions. In particular, the experimental sensor remained operational at 275/sup 0/C and 7000 psi.

  18. Borehole drilling and related activities at the Stripa mine

    Energy Technology Data Exchange (ETDEWEB)

    Kurfurst, P.J.; Hugo-Persson, T.; Rudolph, G.


    Drilling operations for the joint Swedish-U.S. program on radioactive waste storage in mined caverns were conducted from August, 1977 to April, 1978. At the peak of drilling, six drills were active, one on the surface and five underground. 160 boreholes were drilled with sizes ranging from 38 to 406 mm dia. Special techniques and drilling equipment were developed to drill and remove the large cores. Instrumentation and heater installations required strict drilling specifications. Detailed descriptions of the fractures and other relevant rock properties required orientation of the core as well as special recovery techniques. To assure the best possible quality of the core, a triple-tube core barrel was used to drill all boreholes 76 mm diameter and larger.

  19. Comparing plume characteristics inferred from cross-borehole geophysical data

    DEFF Research Database (Denmark)

    Haarder, Eline Bojsen; Binley, Andrew; Zibar, Majken Caroline Looms


    Three cross-borehole geophysical methods are used to image water migration in the unsaturated zone after a point injection of water. Mass balance calculations and moment analysis highlight the differences in resolution between the methods. The choice of moisture content threshold value...... significantly influences results of the moment analysis. We compare results of three cross-borehole geophysical approaches for imaging tracer migration arising from a point injection of water in the unsaturated zone: three-dimensional electrical resistivity tomography (ERT), two-dimensional ground......-penetrating radar (GPR) tomography and quasi-three-dimensional GPR tomography. In the studied field experiment, a tracer was injected for a period of 5 d and was monitored both during injection and for 5 d during the subsequent redistribution. The three methods show similar characteristics of the plume development...

  20. Nitrates and nitrites content of water boreholes and packaged water ...

    African Journals Online (AJOL)

    Nitrate and nitrite levels were determined in forty-three water samples obtained from different locations in Calabar using colorimetric methods. Twenty-three of these samples were packaged water while twenty were borehole water. Nitrate levels were found to be 24.28 ± 9.30μg/ml and 34.57 ± 14.56µ/ml for packaged water ...

  1. Bacteriological analysis of borehole water in Uli, Nigeria | Ibe ...

    African Journals Online (AJOL)

    Water samples from four different boreholes within Uli, Anambra State, Nigeria, were collected for five consecutive weeks for bacteriological analysis to assess the potability.The range of the means was from 1.5x102 to 5.9x104 cfu ml-1 for total aerobic bacterial load, 9 to 136 MPN per 100ml for total coliforms and 4 to 74 ...

  2. Linearized inversion frameworks toward high-resolution seismic imaging

    KAUST Repository

    Aldawood, Ali


    Seismic exploration utilizes controlled sources, which emit seismic waves that propagate through the earth subsurface and get reflected off subsurface interfaces and scatterers. The reflected and scattered waves are recorded by recording stations installed along the earth surface or down boreholes. Seismic imaging is a powerful tool to map these reflected and scattered energy back to their subsurface scattering or reflection points. Seismic imaging is conventionally based on the single-scattering assumption, where only energy that bounces once off a subsurface scatterer and recorded by a receiver is projected back to its subsurface position. The internally multiply scattered seismic energy is considered as unwanted noise and is usually suppressed or removed from the recorded data. Conventional seismic imaging techniques yield subsurface images that suffer from low spatial resolution, migration artifacts, and acquisition fingerprint due to the limited acquisition aperture, number of sources and receivers, and bandwidth of the source wavelet. Hydrocarbon traps are becoming more challenging and considerable reserves are trapped in stratigraphic and pinch-out traps, which require highly resolved seismic images to delineate them. This thesis focuses on developing and implementing new advanced cost-effective seismic imaging techniques aiming at enhancing the resolution of the migrated images by exploiting the sparseness of the subsurface reflectivity distribution and utilizing the multiples that are usually neglected when imaging seismic data. I first formulate the seismic imaging problem as a Basis pursuit denoise problem, which I solve using an L1-minimization algorithm to obtain the sparsest migrated image corresponding to the recorded data. Imaging multiples may illuminate subsurface zones, which are not easily illuminated by conventional seismic imaging using primary reflections only. I then develop an L2-norm (i.e. least-squares) inversion technique to image

  3. Hydraulic Actuators with Autonomous Hydraulic Supply for the Mainline Aircrafts

    Directory of Open Access Journals (Sweden)

    I. S. Shumilov


    Full Text Available Applied in the aircraft control systems, hydraulic servo actuators with autonomous hydraulic supply, so-called, hydraulic actuators of integrated configuration, i.e. combination of a source of hydraulic power and its load in the single unit, are aimed at increasing control system reliability both owing to elimination of the pipelines connecting the actuator to the hydraulic supply source, and owing to avoidance of influence of other loads failure on the actuator operability. Their purpose is also to raise control system survivability by eliminating the long pipeline communications and their replacing for the electro-conductive power supply system, thus reducing the vulnerability of systems. The main reason for a delayed application of the hydraulic actuators in the cutting-edge aircrafts was that such aircrafts require hydraulic actuators of considerably higher power with considerable heat releases, which caused an unacceptable overheat of the hydraulic actuators. Positive and negative sides of the hydraulic actuators, their alternative options of increased reliability and survivability, local hydraulic systems as an advanced alternative to independent hydraulic actuators are considered.Now to use hydraulic actuators in mainline aircrafts is inexpedient since there are the unfairly large number of the problems reducing, first and last, safety of flights, with no essential weight and operational advantages. Still works to create competitive hydraulic actuators ought to be continued.Application of local hydraulic systems (LHS will allow us to reduce length of pressure head and drain pipelines and mass of pipelines, as well as to raise their general fail-safety and survivability. Application of the LHS principle will allow us to use a majority of steering drive advantages. It is necessary to allocate especially the following:- ease of meeting requirements for the non-local spread of the engine weight;- essentially reducing length and weight of

  4. Electrokinetic high pressure hydraulic system (United States)

    Paul, Phillip H.; Rakestraw, David J.


    A compact high pressure hydraulic pump having no moving mechanical parts for converting electric potential to hydraulic force. The electrokinetic pump, which can generate hydraulic pressures greater than 2500 psi, can be employed to compress a fluid, either liquid or gas, and manipulate fluid flow. The pump is particularly useful for capillary-base systems. By combining the electrokinetic pump with a housing having chambers separated by a flexible member, fluid flow, including high pressure fluids, is controlled by the application of an electric potential, that can vary with time.

  5. Hydraulic pressure variations of groundwater in the Gran Sasso underground laboratory during Amatrice earthquake of August 24th, 2016

    Directory of Open Access Journals (Sweden)

    Gaetano De Luca


    Full Text Available Since May 2015, hydraulic pressure, temperature and electrical conductivity of groundwater are in continuos recording near the deep underground laboratories of Gran Sasso of INFN. We used the S13 borehole that have pressure varying in the range of 24-28 bar during the year; these values mean that we have at least 300 m of water table above. The sampling of these parameters was brought until to 50 Hz using a 3 channels 24-bit ADC. During the period May 2015 – September 2016 (17 months we detected hydraulic pressure signals from 12 earthquakes at different surface distances (from 12.000 to 30 km and different magnitudes (from 8.3 to 4.3 Mw. For the Amatrice mainshock, we present, as first results, the hydroseismograph recorded at the S13 hydraulic pressure device compared to the time history recorded at GIGS station located both in the deep core of the Gran Sasso chain.

  6. A Long-Term Strategic Plan for Hanford Sediment Physical Property and Vadose Zone Hydraulic Parameter Databases

    Energy Technology Data Exchange (ETDEWEB)

    Rockhold, Mark L.; Last, George V.; Middleton, Lisa A.


    Physical property data and unsaturated hydraulic parameters are critical input for analytic and numerical models used to predict transport and fate of contaminants in variably saturated porous media and to assess and execute remediation alternatives. The Remediation Decision Support (RDS) project, managed by the Pacific Northwest National Laboratory (PNNL) for the U.S. Department of Energy (DOE) and the CH2M Hill Plateau Remediation Company (CHPRC), has been compiling physical and hydraulic property data and parameters to support risk analyses and waste management decisions at Hanford. Efforts have been initiated to transfer sediment physical property data and vadose zone hydraulic parameters to CHPRC for inclusion in HEIS-Geo, a new instance of the Hanford Environmental Information System database that is being developed for borehole geologic data. This report describes these efforts and a strategic plan for continued updating and improvement of these datasets.

  7. Site Guidelines for a Deep Borehole Field Test (United States)

    Sassani, D.; Kuhlman, K. L.; Freeze, G. A.; MacKinnon, R. J.; Perry, F.


    The US DOE Office of Nuclear Energy Used Nuclear Fuel Disposition Campaign (UFDC) is initiating a Deep Borehole Field Test (DBFT), without use of any radioactive waste, to evaluate the geoscience of the approach and technical capabilities for implementation. DOE has identified Sandia National Laboratories (SNL) as the Technical Lead for the UFDC DBFT Project, with the role of supporting DOE in (i) developing the overall DBFT Project Plan, (ii) management and integration of all DBFT Project activities, and (iii) providing Project technical guidance to DOE, other DOE National Laboratories, and university partners. The DBFT includes drilling one Characterization Borehole (CB-8.5" diameter), followed by an optional Field Test Borehole (FTB), to a depth of about 5,000 m (16,400 feet) into crystalline basement rock in a geologically stable continental location. The DBFT CB will be drilled and completed to facilitate downhole scientific testing and analyses. If site conditions are found to be favorable, DOE may drill the larger-diameter (17") FTB to facilitate proof-of-concept of handling, emplacement, and retrieval activities using surrogate waste containers. Guidelines for favorable DBFT site geohydrochemical and geomechanical conditions will be discussed and status of the DBFT Project will be provided. Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the United States Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000. SAND2015-6426A.


    Directory of Open Access Journals (Sweden)

    S. V. Popov


    Full Text Available The results of the remote sensing which carried out in the LakeVostokarea are discussed in the paper. A.P. Kapitsa and O.G. Sorokhtin started the geophysical researches in this area in 1950s. Satellite altimetry data, which analyzed in 1990s yielded to the discovering of the LakeVostok. After that, PMGE and RAE started the systematic studying of this natural phenomenon by seismic and radio-echo sounding. Total, 318 seismic soundings and 5190 kmof the radio-echo profiles has been collected by 2008. Special precise measurements which carried out in the 5G-1 borehole vicinity are resulted in the ice thickness over Vostok Station is 3760±30 mby seismic and 3775±15 mby radio-echo sounding. Thus, the error of geophysical measurements is less than 0.3%. The Russian investigations are resulted in definition the border of the lake, the discovering of 56 subglacial water caves around the lake and compilation the maps including ice thickness, ice base and bedrock topography and the depth of the lake. Average depth of the LakeVostokis about 400 m; water volume is 6100 km3. After 2008, the remote sensing works have been concentrated to the studying of the bottom sediments by refraction seismic technique. The firsts result shown that the bottom sediments thickness varies from 400 to1200 m.

  9. Seismic Catalogue and Seismic Network in Haiti (United States)

    Belizaire, D.; Benito, B.; Carreño, E.; Meneses, C.; Huerfano, V.; Polanco, E.; McCormack, D.


    The destructive earthquake occurred on January 10, 2010 in Haiti, highlighted the lack of preparedness of the country to address seismic phenomena. At the moment of the earthquake, there was no seismic network operating in the country, and only a partial control of the past seismicity was possible, due to the absence of a national catalogue. After the 2010 earthquake, some advances began towards the installation of a national network and the elaboration of a seismic catalogue providing the necessary input for seismic Hazard Studies. This paper presents the state of the works carried out covering both aspects. First, a seismic catalogue has been built, compiling data of historical and instrumental events occurred in the Hispaniola Island and surroundings, in the frame of the SISMO-HAITI project, supported by the Technical University of Madrid (UPM) and Developed in cooperation with the Observatoire National de l'Environnement et de la Vulnérabilité of Haiti (ONEV). Data from different agencies all over the world were gathered, being relevant the role of the Dominican Republic and Puerto Rico seismological services which provides local data of their national networks. Almost 30000 events recorded in the area from 1551 till 2011 were compiled in a first catalogue, among them 7700 events with Mw ranges between 4.0 and 8.3. Since different magnitude scale were given by the different agencies (Ms, mb, MD, ML), this first catalogue was affected by important heterogeneity in the size parameter. Then it was homogenized to moment magnitude Mw using the empirical equations developed by Bonzoni et al (2011) for the eastern Caribbean. At present, this is the most exhaustive catalogue of the country, although it is difficult to assess its degree of completeness. Regarding the seismic network, 3 stations were installed just after the 2010 earthquake by the Canadian Government. The data were sent by telemetry thought the Canadian System CARINA. In 2012, the Spanish IGN together

  10. Induced seismicity in the Tbilisi region, East Georgia (United States)

    Melikadze, G.; Chelidze, T.; Jimsheladze, T.


    The paper gives an overview on the underground fluid and geodynamical response to oil production processes and discusses the possible oil pumping-induced seismicity in the Tbilisi region, Georgia. The intensive oil production in 80-s disturbs the regime of the central hydrothermal deposit and causes depletion and desalination of springs. Analysis of data in the period of intensive increase in oil production rate at the Samgori-Ninotsminda oil field in 1975 and its drastic decrease in 1985 points to close connection of hydrological regime of thermal water in boreholes #1 Botanic-Garden (1 BG) with oil production level: fast increase of oil production leads to drastic decrease of debit in the central borehole to almost zero and 20-meters decrease of water level in the with some relatively long (month) time lags. Water debit in 1BG begin slow recovery after termination of pumping. In Tbilisi region during 1970-1989 was produced more than 5.1010 to kg of oil so according to existing statistics the level of extraction is close to critical for appearance of induced seismicity. The stress change induced by hydrocarbon extraction is as a rule small, but the deviatory stress exceeding 0.01 MPa may trigger seismic activity. In order to distinguish the seismohydraulic effect we plotted the seismic activity (SA) versus time in the time interval, covering periods before (1960-1970), during (1970-1989) and after termination (1990-2004) of oil production interval. To exclude the effect of local seismic network changes during 1960-2004 only the catalog of the Tbilisi Seismic Observatory (TSO), where the registration conditions were not changed in this period has been used. In the analyzed catalog were included events occurred within circular area of radius 50 km around TSO. Three types of TSO catalog were analyzed: TSO1 included all events, recorded at the observatory, even smallest ones; TSO2 included only the events of magnitude M  2.5; TSO3 included the events of magnitude M

  11. Seismic Imaging of Receiver Functions at Virtual Receivers in Ryukyu Arc, Japan (United States)

    Murakoshi, T.; Takenaka, H.; Komatsu, M.; Yamada, N.


    This study describes the seismic images of the crust and uppermost mantle beneath the Ryukyu Arc, Japan by using S-wavevector receiver functions (SWV-RFs) analysis at virtual subsurface receivers. The SWV-RFs are the time series deconvolving the upgoing SV-wave component by the upgoing P-wave one. This method for ground surface records was originally introduced by Reading et al. (2003, GRL). Takenaka and Murakoshi (2010, AGU) proposed the SWV-RFs at the surface or subsurface station, which virtually move the seismic sensor at the surface or in the borehole down to the top of the basement layer and calculate the SWV-RFs at that location for suppressing the sedimentary layer effect. The SWV-RFs have a great advantage that the problem of unclearly seismic images beneath very thick sedimentary basin due to the records include strong effect of reverberation within the sedimentary layer can be overcome. Takenaka et al. (2014, AGU) applied the SWV-RFs to the teleseismic waveform records observed at borehole and ground surface stations and obtained clearly seismic images of Moho and subducted Philippine Sea plate beneath in Kyushu island, Japan. In this study, we applied the SWV-RFs from broadband seismic records of the F-net (NIED) and ETOS (JMA) to obtain the seismic structures in Ryukyu Arc, Japan. In this presentation, we will show the estimated seismic structure under each stations in the Ryukyu Arc, Japan. Acknowledgement: We have used Fnet data (NIED), ETOS data (JMA) and deep subsurface structure model by J-SHIS (NIED).

  12. Advanced seismic imaging of overdeepened alpine valleys (United States)

    Burschil, Thomas; Buness, Hermann; Tanner, David; Gabriel, Gerald; Krawczyk, Charlotte M.


    Major European alpine valleys and basins are densely populated areas with infrastructure of international importance. To protect the environment by, e.g., geohazard assessment or groundwater estimation, understanding of the geological structure of these valleys is essential. The shape and deposits of a valley can clarify its genesis and allows a prediction of behaviour in future glaciations. The term "overdeepened" refers to valleys and basins, in which pressurized melt-water under the glacier erodes the valley below the fluvial level. Most overdeepened valleys or basins were thus refilled during the ice melt or remain in the form of lakes. The ICDP-project Drilling Overdeepened Alpine Valleys (DOVE) intends to correlate the sedimentary succession from boreholes between valleys in the entire alpine range. Hereby, seismic exploration is essential to predict the most promising well path and drilling site. In a first step, this DFG-funded project investigates the benefit of multi-component techniques for seismic imaging. At two test sites, the Tannwald Basin and the Lienz Basin, the Leibniz Institute for Applied Geophysics acquired P-wave reflection profiles to gain structural and facies information. Built on the P-wave information, several S-wave reflection profiles were acquired in the pure SH-wave domain as well as 6-C reflection profiles using a horizontal S-wave source in inline and crossline excitation and 3-C receivers. Five P-wave sections reveal the structure of the Tannwald Basin, which is a distal branch basin of the Rhine Glacier. Strong reflections mark the base of the basin, which has a maximum depth of 240 metres. Internal structures and facies vary strongly and spatially, but allow a seismic facies characterization. We distinguish lacustrine, glacio-fluvial, and deltaic deposits, which make up the fill of the Tannwald Basin. Elements of the SH-wave and 6-C seismic imaging correlate with major structures in the P-wave image, but vary in detail. Based on

  13. Co-seismic response of water level in the Jingle well (China) associated with the Gorkha Nepal (Mw 7.8) earthquake (United States)

    He, Anhua; Fan, Xuefang; Zhao, Gang; Liu, Yang; Singh, Ramesh P.; Hu, Yuliang


    Changes in co-seismic water levels associated with the Gorkha Nepal earthquake (25 April 2015, Mw 7.8) were recorded in the Jingle well in Shanxi Province China (longitude E112.03°, latitude N38.35°, about 2769 km from epicenter). Based on the observed water levels, we clearly identified signals relating to P, S and surface waves. However, the water temperature recorded at a depth of 350 m shows no co-seismic changes. A spectrum analysis of co-seismic variations of water level shows that the oscillation frequency and amplitude of water level in the borehole are determined by the natural frequency of the borehole, which is not associated with the propagation of seismic waves. The borehole-aquifer system shows a large amplification associated with ground vibrations generated by earthquakes. Considering the local hydro-geological map and the temperature gradient of the Jingle well, a large volume ;groundwater reservoir; model can be used to explain these processes. Due to seismic wave propagation, the volume of a well-confined aquifer expands and contracts forming fractures that change the water flow. In the well-confined aquifer, water levels oscillate simultaneously with high amplitude ground shaking during earthquakes. However, the water in the center of the ;underground reservoir; remains relatively stationary, without any changes in the water temperature. In addition, a possible precursor wave is recorded in the water level at the Jingle well prior to the Gorkha earthquake.

  14. Comparison of shear-wave slowness profiles at 10 strong-motion sites from noninvasive SASW measurements and measurements made in boreholes (United States)

    Brown, L.T.; Boore, D.M.; Stokoe, K.H.


    The spectral-analysis-of-surface-waves (SASW) method is a relatively new in situ method for determining shear-wave slownesses. All measurements are made on the ground surface, making it much less costly than methods that require boreholes. The SASW method uses a number of active sources (ranging from a commercial Vibroseis truck to a small handheld hammer for the study conducted here) and different receiver spacings to map a curve of apparent phase velocity versus frequency. With the simplifying assumption that the phase velocities correspond to fundamental mode surface waves, forward modeling yields an estimate of the sub-surface shear-wave slownesses. To establish the reliability of this indirect technique, we conducted a blind evaluation of the SASW method. SASW testing was performed at 10 strong-motion stations at which borehole seismic measurements were previously or subsequently made; if previously made, the borehole results were not used for the interpretation of the SASW data, and vice-versa. Comparisons of the shear-wave slownesses from the SASW and borehole measurements are generally very good. The differences in predicted ground-motion amplifications are less than about 15% for most frequencies. In addition, both methods gave the same NEHRP site classification for seven of the sites. For the other three sites the average velocities from the downhole measurements were only 5-13 m/sec larger than the velocity defining the class C/D boundary. This study demonstrates that in many situations the SASW method can provide subsurface information suitable for site response predictions.


    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...


    Federal Emergency Management Agency, Department of Homeland Security — Hydraulic data include spatial datasets and data tables necessary for documenting the hydrologic procedures for estimating flood discharges for a flood insurance...

  17. The Process of Hydraulic Fracturing (United States)

    Hydraulic fracturing, know as fracking or hydrofracking, produces fractures in a rock formation by pumping fluids (water, proppant, and chemical additives) at high pressure down a wellbore. These fractures stimulate the flow of natural gas or oil.

  18. Interpretation of resonance frequencies recorded during hydraulic fracturing treatments (United States)

    Tary, J. B.; van der Baan, M.; Eaton, D. W.


    Hydraulic fracturing treatments are often monitored by strings of geophones deployed in boreholes. Instead of picking discrete events only, we here use time-frequency representations of continuous recordings to identify resonances in two case studies. This paper outlines an interpretational procedure to identify their cause using a subdivision into source, path, and receiver-side effects. For the first case study, two main resonances are observed both at depth by the downhole geophones and on the surface by two broadband arrays. The two acquisition networks have different receiver and path effects, yet recorded the same resonances; these resonances are therefore likely generated by source effects. The amplitude pattern at the surface arrays indicates that these resonances are probably due to pumping operations. In the second case study, selective resonances are detected by the downhole geophones. Resonances coming from receiver effects are either lower or higher frequency, and wave propagation modeling shows that path effects are not significant. We identify two possible causes within the source area, namely, eigenvibrations of fractures or non-Darcian flow within the hydraulic fractures. In the first situation, 15-30 m long fluid-filled cracks could generate the observed resonances. An interconnected fracture network would then be required, corresponding to mesoscale deformation of the reservoir. Alternatively, systematic patterns in non-Darcian fluid flow within the hydraulic fracture could also be their leading cause. Resonances can be used to gain a better understanding of reservoir deformations or dynamic fluid flow perturbations during fluid injection into hydrocarbon and geothermal reservoirs, CO2 sequestration, or volcanic eruptions.

  19. Imaging Seismic Reflections

    NARCIS (Netherlands)

    op 't Root, T.J.P.M.; Op 't Root, Timotheus Johannes Petrus Maria


    The goal of reflection seismic imaging is making images of the Earth subsurface using surface measurements of reflected seismic waves. Besides the position and orientation of subsurface reflecting interfaces it is a challenge to recover the size or amplitude of the discontinuities. We investigate

  20. A magnetotelluric investigation of the Scandinavian Caledonides in western Jämtland, Sweden, using the COSC borehole logs as prior information (United States)

    Yan, Ping; Garcia Juanatey, Maria A.; Kalscheuer, Thomas; Juhlin, Christopher; Hedin, Peter; Savvaidis, Alexandros; Lorenz, Henning; Kück, Jochem


    In connection with the Collisional Orogeny in the Scandinavian Caledonides (COSC) project, broad-band magnetotelluric (MT) data were acquired at 78 stations along a recent ca. 55-km-long NW-SE directed reflection seismic profile (referred to as the COSC Seismic Profile; CSP), with the eastern end located ∼30 km to the west of the orogenic Caledonian front. The MT component of the project aims at (i) delineating the highly conductive (∼0.1 Ω ṡ m) alum shales that are associated with an underlying main décollement and (ii) calibrating the MT model to borehole logs. Strike and distortion analyses of the MT data show a 3-D structure in the western 10 km of the profile around the 2.5 km deep COSC-1 borehole (IGSN: ICDP5054EHW1001) and a preferred strike angle of N34°E in the central and eastern parts of the profile. 2-D modelling of MT impedances was tested using different inversion schemes and parameters. To adjust the resistivity structure locally around the borehole, resistivity logging data from COSC-1 were successfully employed as prior constraints in the 2-D MT inversions. Compared with the CSP, the model inverted from the determinant impedances shows the highest level of structural similarity. A shallow resistor (>1000 Ω ṡ m) in the top 2-3 km depth underneath the western most 10 km of the profile around COSC-1 corresponds to a zone of high seismic reflectivity, and a boundary at less than 1 km depth where the resistivity decreases rapidly from >100 to 3 km depth. Based upon the COSC-1 borehole logs, the CSP reflection seismic image, and the surface geologic map, the MT resistivity models were interpreted geologically. In the vicinity of COSC-1, the resistor down to 2-3 km depth pertains to the metamorphic Middle Allochthon. The up to 1000-m-thick shallow resistor in the central and eastern parts of the profile is interpreted to overly an imbricated unit at the bottom of the Lower Allochthon that includes the alum shales. In the MT resistivity model

  1. Hydraulic rams; a comparative investigation


    Tacke, J.H.P.M.


    A mathematical model describing the essential features of hydraulic ram operation is developed in order to clarify the possibilities and limitations of the ram relative to its site and its adjustments. The model distinguishes three different periods in the pumping cycle of the hydraulic ram: acceleration - retardation - recoil. Making use of the theory of unsteady flow in pipelines. for each period the relation between velocity and time is derived for the water in the drive pipe of the hydrau...

  2. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images (United States)

    Tian, Fei; Lu, Xinbian; Zheng, Songqing; Zhang, Hongfang; Rong, Yuanshuai; Yang, Debin; Liu, Naigui


    The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills) and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  3. Structure and Filling Characteristics of Paleokarst Reservoirs in the Northern Tarim Basin, Revealed by Outcrop, Core and Borehole Images

    Directory of Open Access Journals (Sweden)

    Tian Fei


    Full Text Available The Ordovician paleokarst reservoirs in the Tahe oilfield, with burial depths of over 5300 m, experienced multiple phases of geologic processes and exhibit strong heterogeneity. Core testing can be used to analyse the characteristics of typical points at the centimetre scale, and seismic datasets can reveal the macroscopic outlines of reservoirs at the >10-m scale. However, neither method can identify caves, cave fills and fractures at the meter scale. Guided by outcrop investigations and calibrations based on core sample observations, this paper describes the interpretation of high longitudinal resolution borehole images, the identification of the characteristics of caves, cave fills (sedimentary, breccia and chemical fills and fractures in single wells, and the identification of structures and fill characteristics at the meter scale in the strongly heterogeneous paleokarst reservoirs. The paleogeomorphology, a major controlling factor in the distribution of paleokarst reservoirs, was also analysed. The results show that one well can penetrate multiple cave layers of various sizes and that the caves are filled with multiple types of fill. The paleogeomorphology can be divided into highlands, slopes and depressions, which controlled the structure and fill characteristics of the paleokarst reservoirs. The results of this study can provide fundamental meter-scale datasets for interpreting detailed geologic features of deeply buried paleocaves, can be used to connect core- and seismic-scale interpretations, and can provide support for the recognition and development of these strongly heterogeneous reservoirs.

  4. Ground gas monitoring: implications for hydraulic fracturing and CO2 storage. (United States)

    Teasdale, Christopher J; Hall, Jean A; Martin, John P; Manning, David A C


    Understanding the exchange of carbon dioxide (CO2) and methane (CH4) between the geosphere and atmosphere is essential for the management of anthropogenic emissions. Human activities such as carbon capture and storage and hydraulic fracturing ("fracking") affect the natural system and pose risks to future global warming and to human health and safety if not engineered to a high standard. In this paper an innovative approach of expressing ground gas compositions is presented, using data derived from regulatory monitoring of boreholes in the unsaturated zone at infrequent intervals (typically 3 months) with data from a high frequency monitoring instrument deployed over periods of weeks. Similar highly variable trends are observed for time scales ranging from decades to hourly for boreholes located close to sanitary landfill sites. Additionally, high frequency monitoring data confirm the effect of meteorological controls on ground gas emissions; the maximum observed CH4 and CO2 concentrations in a borehole monitored over two weeks were 40.1% v/v and 8.5% v/v respectively, but for 70% of the monitoring period only air was present. There is a clear weakness in current point monitoring strategies that may miss emission events and this needs to be considered along with obtaining baseline data prior to starting any engineering activity.

  5. A study on seismicity and seismic hazard for Karnataka State

    Indian Academy of Sciences (India)

    Home; Journals; Journal of Earth System Science; Volume 121; Issue 2. A study on seismicity and seismic hazard for Karnataka State. T G Sitharam Naveen ... This paper presents a detailed study on the seismic pattern of the state of Karnataka and also quantifies the seismic hazard for the entire state. In the present work, ...

  6. Delineation of seismic source zones based on seismicity parameters ...

    Indian Academy of Sciences (India)

    The delineation of seismic source zones plays an important role in the evaluation of seismic hazard. In most of the studies the seismic source delineation is done based on geological features. In the present study, an attempt has been made to delineate seismic source zones in the study area (south India) based on the ...

  7. Seismic Endoscopy: Design of New Instruments (United States)

    Conil, F.; Nicollin, F.; Gibert, D.


    In order to perform 3D images around shallow-depth boreholes, in conditions in the field and within reasonable times of data acquisitions, several instrumental developments have been performed. The first development concerns the design of a directional probe working in the 20-100 kHz frequency range; the idea is to create a tool composed of multiple elementary piezoelectric entities able to cover the whole space to explore; made of special polyurethane rigid foam with excellent attenuation performances, the prototypes are covered by flexible polyurethane electric resin. By multiplying the number of elementary receptors around the vertical axes and piling up each elementary sensor, a complete design of multi-azimuth and multi-offset has been concepted. In addition to this, a test site has been built in order to obtain a controlled medium at typical scales of interest for seismic endoscopy and dedicated to experiment near the conditions in the field. Various reflectors are placed in well known positions and filled in an homogeneous cement medium; the whole edifice (2.2 m in diameter and 8 metres in depth) also contains 4 PVC tubes to simulate boreholes. The second part of this instrumental developments concern the synthesis of input signals; indeed, many modern devices used in ultrasonic experiment have non linear output response outside their nominal range: this is especially true in geophysical acoustical experiments when high acoustical power is necessary to insonify deep geological targets. Thanks to the high speed electronic and computerised devices now available, it is possible to plug in experimental set-ups into non linear inversions algorithms like simulated annealing. First experiments showed the robustness of the method in case of non linear analogic architecture. Large wavelet families have or example been constructed thanks to the method and multiscale Non Destructive Testing Method have been performed as an efficient method to detect and characterise

  8. Hydraulic fracturing - an attempt of DEM simulation (United States)

    Kosmala, Alicja; Foltyn, Natalia; Klejment, Piotr; Dębski, Wojciech


    Hydraulic fracturing is a technique widely used in oil, gas and unconventional reservoirs exploitation in order to enable the oil/gas to flow more easily and enhance the production. It relays on pumping into a rock a special fluid under a high pressure which creates a set of microcracks which enhance porosity of the reservoir rock. In this research, attempt of simulation of such hydrofracturing process using the Discrete Element Method approach is presented. The basic assumption of this approach is that the rock can be represented as an assembly of discrete particles cemented into a rigid sample (Potyondy 2004). An existence of voids among particles simulates then a pore system which can be filled out by fracturing fluid, numerically represented by much smaller particles. Following this microscopic point of view and its numerical representation by DEM method we present primary results of numerical analysis of hydrofracturing phenomena, using the ESyS-Particle Software. In particular, we consider what is happening in distinct vicinity of the border between rock sample and fracking particles, how cracks are creating and evolving by breaking bonds between particles, how acoustic/seismic energy is releasing and so on. D.O. Potyondy, P.A. Cundall. A bonded-particle model for rock. International Journal of Rock Mechanics and Mining Sciences, 41 (2004), pp. 1329-1364.

  9. Seismic risk assessment of Navarre (Northern Spain) (United States)

    Gaspar-Escribano, J. M.; Rivas-Medina, A.; García Rodríguez, M. J.; Benito, B.; Tsige, M.; Martínez-Díaz, J. J.; Murphy, P.


    The RISNA project, financed by the Emergency Agency of Navarre (Northern Spain), aims at assessing the seismic risk of the entire region. The final goal of the project is the definition of emergency plans for future earthquakes. With this purpose, four main topics are covered: seismic hazard characterization, geotechnical classification, vulnerability assessment and damage estimation to structures and exposed population. A geographic information system is used to integrate, analyze and represent all information colleted in the different phases of the study. Expected ground motions on rock conditions with a 90% probability of non-exceedance in an exposure time of 50 years are determined following a Probabilistic Seismic Hazard Assessment (PSHA) methodology that includes a logic tree with different ground motion and source zoning models. As the region under study is located in the boundary between Spain and France, an effort is required to collect and homogenise seismological data from different national and regional agencies. A new homogenised seismic catalogue, merging data from Spanish, French, Catalonian and international agencies and establishing correlations between different magnitude scales, is developed. In addition, a new seismic zoning model focused on the study area is proposed. Results show that the highest ground motions on rock conditions are expected in the northeastern part of the region, decreasing southwards. Seismic hazard can be expressed as low-to-moderate. A geotechnical classification of the entire region is developed based on surface geology, available borehole data and morphotectonic constraints. Frequency-dependent amplification factors, consistent with code values, are proposed. The northern and southern parts of the region are characterized by stiff and soft soils respectively, being the softest soils located along river valleys. Seismic hazard maps including soil effects are obtained by applying these factors to the seismic hazard maps

  10. Classifying zones of suitability for manual drilling using textural and hydraulic parameters of shallow aquifers: a case study in northwestern Senegal (United States)

    Fussi, F. Fabio; Fumagalli, Letizia; Fava, Francesco; Di Mauro, Biagio; Kane, Cheik Hamidou; Niang, Magatte; Wade, Souleye; Hamidou, Barry; Colombo, Roberto; Bonomi, Tullia


    A method is proposed that uses analysis of borehole stratigraphic logs for the characterization of shallow aquifers and for the assessment of areas suitable for manual drilling. The model is based on available borehole-log parameters: depth to hard rock, depth to water, thickness of laterite and hydraulic transmissivity of the shallow aquifer. The model is applied to a study area in northwestern Senegal. A dataset of boreholes logs has been processed using a software package (TANGAFRIC) developed during the research. After a manual procedure to assign a standard category describing the lithological characteristics, the next step is the automated extraction of different textural parameters and the estimation of hydraulic conductivity using reference values available in the literature. The hydraulic conductivity values estimated from stratigraphic data have been partially validated, by comparing them with measured values from a series of pumping tests carried out in large-diameter wells. The results show that this method is able to produce a reliable interpretation of the shallow hydrogeological context using information generally available in the region. The research contributes to improving the identification of areas where conditions are suitable for manual drilling. This is achieved by applying the described method, based on a structured and semi-quantitative approach, to classify the zones of suitability for given manual drilling techniques using data available in most African countries. Ultimately, this work will support proposed international programs aimed at promoting low-cost water supply in Africa and enhancing access to safe drinking water for the population.

  11. Classifying zones of suitability for manual drilling using textural and hydraulic parameters of shallow aquifers: a case study in northwestern Senegal (United States)

    Fussi, F. Fabio; Fumagalli, Letizia; Fava, Francesco; Di Mauro, Biagio; Kane, Cheik Hamidou; Niang, Magatte; Wade, Souleye; Hamidou, Barry; Colombo, Roberto; Bonomi, Tullia


    A method is proposed that uses analysis of borehole stratigraphic logs for the characterization of shallow aquifers and for the assessment of areas suitable for manual drilling. The model is based on available borehole-log parameters: depth to hard rock, depth to water, thickness of laterite and hydraulic transmissivity of the shallow aquifer. The model is applied to a study area in northwestern Senegal. A dataset of boreholes logs has been processed using a software package (TANGAFRIC) developed during the research. After a manual procedure to assign a standard category describing the lithological characteristics, the next step is the automated extraction of different textural parameters and the estimation of hydraulic conductivity using reference values available in the literature. The hydraulic conductivity values estimated from stratigraphic data have been partially validated, by comparing them with measured values from a series of pumping tests carried out in large-diameter wells. The results show that this method is able to produce a reliable interpretation of the shallow hydrogeological context using information generally available in the region. The research contributes to improving the identification of areas where conditions are suitable for manual drilling. This is achieved by applying the described method, based on a structured and semi-quantitative approach, to classify the zones of suitability for given manual drilling techniques using data available in most African countries. Ultimately, this work will support proposed international programs aimed at promoting low-cost water supply in Africa and enhancing access to safe drinking water for the population.

  12. The Effect of Loading Rate on Hydraulic Fracturing in Synthetic Granite - a Discrete Element Study (United States)

    Tomac, I.; Gutierrez, M.


    Hydraulic fracture initiation and propagation from a borehole in hard synthetic rock is modeled using the two dimensional Discrete Element Method (DEM). DEM uses previously established procedure for modeling the strength and deformation parameters of quasi-brittle rocks with the Bonded Particle Model (Itasca, 2004). A series of simulations of laboratory tests on granite in DEM serve as a reference for synthetic rock behavior. Fracturing is enabled by breaking parallel bonds between DEM particles as a result of the local stress state. Subsequent bond breakage induces fracture propagation during a time-stepping procedure. Hydraulic fracturing occurs when pressurized fluid induces hoop stresses around the wellbore which cause rock fracturing and serves for geo-reservoir permeability enhancement in oil, gas and geothermal industries. In DEM, a network of fluid pipes and reservoirs is used for mathematical calculation of fluid flow through narrow channels between DEM particles, where the hydro-mechanical coupling is fully enabled. The fluid flow calculation is superimposed with DEM stress-strain calculation at each time step. As a result, the fluid pressures during borehole pressurization in hydraulic fracturing, as well as, during the fracture propagation from the borehole, can be simulated. The objective of this study is to investigate numerically a hypothesis that fluid pressurization rate, or the fluid flow rate, influences upon character, shape and velocity of fracture propagation in rock. The second objective is to better understand and define constraints which are important for successful fracture propagation in quasi-brittle rock from the perspective of flow rate, fluid density, viscosity and compressibility relative to the rock physical properties. Results from this study indicate that not only too high fluid flow rates cause fracture arrest and multiple fracture branching from the borehole, but also that the relative compressibility of fracturing fluid and

  13. Deep hydraulic tests in a large earth-slide rich in clay (United States)

    Ronchetti, Francesco; Piccinini, Leonardo; Deiana, Manuela; Corsini, Alessandro


    Different hydraulic tests have been conducted and replicated in a large earth slide characterized by a landslide body that is rich in clay, has a mean thickness of 30 meters, and is located in the Northern Apennines, Italy. All the tests were performed to estimate the hydrogeological properties of the landslide and to design future mitigation measures. To define the geometry of the sliding mass, the stratigraphy in more than 15 boreholes was analyzed. The boreholes were subsequently equipped with inclinometers and open standpipe piezometers. According to the stratigraphy, the landslide body is characterized by the presence of gravel layers in a clay-rich matrix. This study compares the results from the different techniques applied to 2 boreholes, 5 open standpipe piezometers and 1 well. The number of tests performed for each test type were 31 slug tests (ST), 4 falling head tests (FT), 5 low-flow pumping tests (PT), 1 point dilution (PD) test, and 2 aquifer tests (AT). Moreover, the test data was evaluated with different solutions. The ST data was evaluated with the Hvorslev and KGS solutions; the FT data was evaluated with the AGI and Hvorslev solutions; the PT data was evaluated with the Muskat solutions; the AT data was evaluated with the Theis, Cooper-Jacob, Neuman, Moench and Tartakosky-Neuman solutions; and the PD test data was evaluated with the classical solution where Darcy velocity is calculated as a function of the rate of dilution. The results show that hydraulic conductivity (K), storage (S) and specific storage (Ss) vary in the horizontal plane and with the depth (K ranges between 1.0E-5 and 1.0E-8 m/s; S ranges between 4.0E-3 and 5E-5; and Ss ranges between 1.0E-3 and 3.0E-3 1/m). The horizontal and vertical variability is correlated with the lithologic heterogeneity highlighted by the borehole stratigraphy. Moreover, all the hydraulic tests conducted on the landslide body give highly consistent results. Comparison of results derived from different

  14. Experimental and theoretical study of hydraulic fracturing in impermeable and permeable materials (United States)

    Rubin, M. B.


    Hydraulic fracture propagation in impermeable and permeable materials was studied. The complicating effects of fluid leak-off and proppant transport were separated by conducting experiments on an impermeable material without proppants, on a permeable material without proppants, and, finally, on the same permeable material with proppants. Borehole pressure, pressure in the fracture, fracture width, and fracture length were measured in both impermeable and permeable experiments. In addition, the extent of fluid penetration into the permeable material was measured in the permeable experiments. It was observed that both the borehole pressure and the pressure gradient in the fracture were considerably larger in the experiments with proppants than in the experiments without proppants. The results of the impermeable and permeable experiments were compared with the corresponding predictions of a solution developed here as well as those of other simple formulas for hydraulic fracture propagation. Although the predictions of the present solution are an improvement over those of the other simple solutions, future research is needed to reduce the discrepancy between theory and experiment. This discrepancy is attributed to the effect of fluid penetration on the fracture mechanics of the permeable medium.

  15. Analysis on the Initial Cracking Parameters of Cross-Measure Hydraulic Fracture in Underground Coal Mines

    Directory of Open Access Journals (Sweden)

    Yiyu Lu


    Full Text Available Initial cracking pressure and locations are important parameters in conducting cross-measure hydraulic fracturing to enhance coal seam permeability in underground coalmines, which are significantly influenced by in-situ stress and occurrence of coal seam. In this study, stress state around cross-measure fracturing boreholes was analyzed using in-situ stress coordinate transformation, then a mathematical model was developed to evaluate initial cracking parameters of borehole assuming the maximum tensile stress criterion. Subsequently, the influences of in-situ stress and occurrence of coal seams on initial cracking pressure and locations in underground coalmines were analyzed using the proposed model. Finally, the proposed model was verified with field test data. The results suggest that the initial cracking pressure increases with the depth cover and coal seam dip angle. However, it decreases with the increase in azimuth of major principle stress. The results also indicate that the initial cracking locations concentrated in the second and fourth quadrant in polar coordinate, and shifted direction to the strike of coal seam as coal seam dip angle and azimuth of maximum principle stress increase. Field investigation revealed consistent rule with the developed model that the initial cracking pressure increases with the coal seam dip angle. Therefore, the proposed mathematical model provides theoretical insight to analyze the initial cracking parameters during cross-measure hydraulic fracturing for underground coalmines.

  16. Seismic architecture of the Chalk Group from onshore reflection data in eastern Denmark

    DEFF Research Database (Denmark)

    Moreau, Julien; Anderskouv, Kresten; Boldreel, Lars Ole

    to compile and merge the geological and geophysical datasets to investigate the variation of the Chalk Group properties and their signature in the subsurface. In this communication, the seismic reflection data are being analysed. Very high resolution litho-, bio- and cyclostratigraphy can be correlated...... of the Chalk Group have been well constrained. Distinct sedimentary facies have been encountered; the sedimentology, the biostratigraphy, the diagenesis and the reservoir properties have been thoroughly investigated and reported. Stimulated by the intensive geological research, the field studies have been...... completed with the acquisition of an extensive set of subsurface data. The data include high resolution 2D multichannel seismics onshore and offshore, a seismic refraction profile, two entirely cored boreholes including wireline logs, GPR cross-hole tomography, thermographic analysis, etc. We intend...

  17. Forecasting Induced Seismicity In Deep Geothermal Energy Projects (United States)

    Király, Eszter; Gischig, Valentin; Karvounis, Dimitrios; Heiniger, Lukas; Wiemer, Stefan


    The decision to phase out nuclear power in Switzerland by 2034 accelerated research on deep geothermal energy, which has the ability to contribute to long-term energy resources. Induced seismicity occurring during early stimulation periods in deep geothermal projects of past years in Switzerland, however, clearly document our limited understanding of the processes at depth that lead to significant seismic hazard and that may influence public acceptance of future projects. Controlling induced seismicity related to deep geothermal projects with adaptive warning systems require models that are forward looking, dynamically updated on the fly as new data arrive and probabilistic in the sense that the inherent uncertainties in our understanding of the processes and in the required model parameters. We currently develop a fully coupled non-linear hydraulic-seismic 3D model joint with a hazard assessment procedure. The goal is to improve the forecasting skill owing to validated physical constraints. As a first step, we seek to answer the question: is it possible to forecast the seismic response of the geothermal site during and after stimulation based on observed seismicity and hydraulic data? Our goal is to find the most suitable model to date for forecasting induced micro-seismicity and unexpected large events in geothermal systems. In order to do so, available stochastic and hybrid models are tested and ranked such as Epidemic Type Aftershock Sequence models, models developed by Shapiro and his research group and two types of geomechanical seed models incorporating linear and non-linear fluid flow. The aim is to balance model prediction performance and model complexity: which parameters are necessary to forecast seismicity well, and which are eventually those that increase model complexity but do not give better results. All tests are performed on the Basel 2006 dataset. Testing is carried out along the guidelines of the Collaboratory for the Study of Earthquake

  18. A strategy to seal exploratory boreholes in unsaturated tuff; Yucca Mountain Site Characterization Project

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez, J.A. [Sandia National Labs., Albuquerque, NM (United States); Case, J.B.; Givens, C.A.; Carney, B.C. [IT Corp., Albuquerque, NM (United States)


    This report presents a strategy for sealing exploratory boreholes associated with the Yucca Mountain Site Characterization Project. Over 500 existing and proposed boreholes have been considered in the development of this strategy, ranging from shallow (penetrating into alluvium only) to deep (penetrating into the groundwater table). Among the comprehensive list of recommendations are the following: Those boreholes within the potential repository boundary and penetrating through the potential repository horizon are the most significant boreholes from a performance standpoint and should be sealed. Shallow boreholes are comparatively insignificant and require only nominal sealing. The primary areas in which to place seals are away from high-temperature zones at a distance from the potential repository horizon in the Paintbrush nonwelded tuff and the upper portion of the Topopah Spring Member and in the tuffaceous beds of the Calico Hills Unit. Seals should be placed prior to waste emplacement. Performance goals for borehole seals both above and below the potential repository are proposed. Detailed construction information on the boreholes that could be used for future design specifications is provided along with a description of the environmental setting, i.e., the geology, hydrology, and the in situ and thermal stress states. A borehole classification scheme based on the condition of the borehole wall in different tuffaceous units is also proposed. In addition, calculations are presented to assess the significance of the boreholes acting as preferential pathways for the release of radionuclides. Design calculations are presented to answer the concerns of when, where, and how to seal. As part of the strategy development, available technologies to seal exploratory boreholes (including casing removal, borehole wall reconditioning, and seal emplacement) are reviewed.

  19. Geologic and geochemical results from boreholes drilled in Yellowstone National Park, Wyoming, 2007 and 2008 (United States)

    Jaworowski, Cheryl; Susong, David; Heasler, Henry; Mencin, David; Johnson, Wade; Conrey, Rick; Von Stauffenberg, Jennipher


    Between 2007 and 2008, seven Earthscope Plate Boundary Observatory (PBO) boreholes ranging in depth from about 200 to 800 feet deep were drilled in and adjacent to the Yellowstone caldera in Yellowstone National Park, for the purpose of installing volcano monitoring instrumentation. Five of the seven boreholes were equipped with strainmeters, downhole seismometers, and tiltmeters. Data collected during drilling included field observations of drill cuttings, stratigraphy within the boreholes, water temperature, and water and drill cuttings samples from selected depths.

  20. Earthquake Seismic Risk Reduction in Ohio: ODNR's Efforts to Address Issues with Natural and Induced Seismicity (United States)

    Besana-Ostman, G. M.


    With the increasing concerns regarding both natural and induced seismicity in Ohio, ODNR (Ohio Department of Natural Resources) initial efforts on seismic risk reduction paved way to various changes and improvement to tackle several major issues. For natural earthquakes, regional seismicity indicates a NE-SW structure in the northern portion of the area associated with a number of moderate historical earthquakes but no active trace identified. On the other hand, earthquakes of 1986 and 2011 are most probably incidents of induced seismicity that trigger more public uproar against disposal of regulated waste waters through injections. ODNR, in efforts to adapt with increasing need to regulate all operations related to both the Utica and Marcellus shale play within the state, had recently strengthen itself both through additional human resources and improved infrastructure. Tougher regulations and additional field tests were required that took effect immediately when a M4 earthquake was associated with the operations of an injection well. Public meetings were undertaken focused on educating many local inhabitants related to oil and gas operations, hydraulic fracturing, injection wells, and seismicity. Trainings for new and existing staff were regularly done especially for field inspection, data management and technology advancements. Considering the existing seismic stations that are few and distant related to sites of the injection wells, additional seismic stations were installed to gather baseline data and monitor for earthquakes within the injection area(s). Furthermore, to assess if the sites of the injection wells are safe from active structures, initial geomorphic and structural analyses indicated possible active faults in the northern portion of state oriented NE-SW. With the above-mentioned recent changes, ODNR had made a significant leap not only in the improvement of its principal regulatory role in the state for oil and gas operations but also in its

  1. Polarimetric borehole radar measurement near Nojima fault and its application to subsurface crack characterization; Polarimetric borehole radar ni yoru Nojima danso shuhen no chika kiretsu keisoku jikken

    Energy Technology Data Exchange (ETDEWEB)

    Sato, M.; Taniguchi, Y.; Miwa, T.; Niitsuma, H. [Tohoku University, Sendai (Japan); Ikeda, R. [National Research Institute for Disaster Prevention, Tsukuba (Japan); Makino, K. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)


    Practical application of subsurface crack characterization by the borehole radar measurement to which the radar polarimetric method was introduced was attempted to measuring objects for which the borehole radar has not been much used, for example, the inside of low loss rock mass or fracture zone where cracks tightly exist. A system was trially manufactured which makes the radar polarimetric measurement possible in the borehole at a 1000m depth and with a about 10cm diameter, and a field experiment was conducted for realizing the subsurface crack characterization near the Nojima fault. For the measuring experiment by the polarimetric borehole radar, used were Iwaya borehole and Hirabayashi borehole drilled in the north of Awaji-shima, Hyogo-ken. In a comparison of both polarization systems of Hirabayashi borehole, reflected waves at depths of 1038m and 1047m are relatively stronger in both polarization systems than those with the same polarization form and at different depths, whereas reflected waves around a 1017m depth are strong only as to the parallel polarization system. Characteristics of the polarization in this experiment indirectly reflect crack structures. 6 refs., 6 figs., 1 tab.

  2. Condensed listing of surface boreholes at the Waste Isolation Pilot Plant Project through 31 December 1995

    Energy Technology Data Exchange (ETDEWEB)

    Hill, L.R.; Aguilar, R.; Mercer, J.W. [Sandia National Labs., Albuquerque, NM (United States); Newman, G. [GRAM, Inc., Albuquerque, NM (United States)


    This report contains a condensed listing of Waste Isolation Pilot Plant (WIPP) project surface boreholes drilled for the purpose of site selection and characterization through 31 December 1995. The US Department of Energy (DOE) sponsored the drilling activities, which were conducted primarily by Sandia National Laboratories. The listing provides physical attributes such as location (township, range, section, and state-plane coordinates), elevation, and total borehole depth, as well as the purpose for the borehole, drilling dates, and information about extracted cores. The report also presents the hole status (plugged, testing, monitoring, etc.) and includes salient findings and references. Maps with borehole locations and times-of-drilling charts are included.

  3. Borehole camera technology and its application in the Three Gorges Project

    Energy Technology Data Exchange (ETDEWEB)

    Wang, C.Y.; Sheng, Q.; Ge, X.R. [Chinese Academy of Sciences, Inst. of Rock and Soil Mechanics, Wuhan (China); Law, K.T. [Carleton Univ., Ottawa, ON (Canada)


    The China's Three Gorges Project is the world's largest hydropower project, consisting of a 1,983-meter long and 185-meter high dam and 26 power generating units. Borehole examination has been conducted at the site to ensure stability of the slope of the ship lock used for navigation. This paper describes 2 systems for borehole inspection and viewing. Both methods of camera borehole technology provide a unique way for geologic engineers to observe the condition inside a borehole. The Axial-View Borehole Television (AVBTV) provides real-time frontal view of the borehole ahead of the probe, making it possible to detect where holes are blocked and to see cracks and other distinctive features in the strata. The Digital Panoramic Borehole Camera System (DPBCS) can collect, measure, save, analyze, manage and displace geological information about a borehole. It can also be used to determine the orientation of discontinuity, generate unrolled image and virtual core graph and conduct statistical analysis. Both camera systems have been demonstrated successfully at the Three Gorges Project for qualitative description of the borehole as well as for quantitative analysis of cracks existing in the rock. It has been determined that most of the cracks dip in the same general direction as the northern slope of the permanent ship lock of the Three Gorges Project. 12 refs., 1 tab., 9 figs.

  4. OSL-thermochronometry of feldspar from the KTB borehole, Germany

    DEFF Research Database (Denmark)

    Guralnik, Benny; Jain, Mayank; Herman, Frédéric


    The reconstruction of thermal histories of rocks (thermochronometry) is a fundamental tool both in Earth science and in geological exploration. However, few methods are currently capable of resolving the low-temperature thermal evolution of the upper ∼2 km of the Earth's crust. Here we introduce ...... recent ambient temperatures of the shallow crust (200 °C Ma−1 range). Although Na-feldspar IRSL is prone to field saturation in colder or slower environments, the method's primary relevance appears to be for borehole and tunnel studies, where it may offer remarkably recent (...

  5. Hydrofracturing water boreholes in hard rock aquifers in Scotland

    CSIR Research Space (South Africa)

    Cobbing, J


    Full Text Available ) J. COBBING & B.É. Ó DOCHARTAIGH182 enlarged, or new fractures are created. This pressure varies, from c. 35 bar in softer rocks to over 140 bar in harder rocks (Ramstad 2004). Fracture opening causes a drop in the injected water pressure..., and increased flow of water into the rock. Pumping of water into the packered interval, at rates of up to c. 300 l min�1, then continues to develop the fractures. After hydrofractur- ing, the injected water is normally pumped or airlifted from the borehole...

  6. The subsurface impact of hydraulic fracturing in shales- Perspectives from the well and reservoir (United States)

    ter Heege, Jan; Coles, Rhys


    It has been identified that the main risks of subsurface shale gas operations in the U.S.A. and Canada are associated with (1) drilling and well integrity, (2) hydraulic fracturing, and (3) induced seismicity. Although it is unlikely that hydraulic fracturing operations result in direct pathways of enhanced migration between stimulated fracture disturbed rock volume and shallow aquifers, operations may jeopardize well integrity or induce seismicity. From the well perspective, it is often assumed that fluid injection leads to the initiation of tensile (mode I) fractures at different perforation intervals along the horizontal sections of shale gas wells if pore pressure exceeds the minimum principal stress. From the reservoir perspective, rise in pore pressure resulting from fluid injection may lead to initiation of tensile fractures, reactivation of shear (mode II) fractures if the criterion for failure in shear is exceeded, or combinations of different fracturing modes. In this study, we compare tensile fracturing simulations using conventional well-based models with shear fracturing simulations using a fractured shale model with characteristic fault populations. In the fractured shale model, stimulated permeability is described by an analytical model that incorporates populations of reactivated faults and that combines 3D permeability tensors for layered shale matrix, damage zone and fault core. Well-based models applied to wells crosscutting the Posidonia Shale Formation are compared to generic fractured shale models, and fractured shale models are compared to micro-seismic data from the Marcellus Shale. Focus is on comparing the spatial distribution of permeability, stimulated reservoir volume and seismicity, and on differences in fracture initiation pressure and fracture orientation for tensile and shear fracturing end-members. It is shown that incorporation of fault populations (for example resulting from analysis of 3D seismics or outcrops) in hydraulic

  7. Selective perceptions of hydraulic fracturing. (United States)

    Sarge, Melanie A; VanDyke, Matthew S; King, Andy J; White, Shawna R


    Hydraulic fracturing (HF) is a focal topic in discussions about domestic energy production, yet the American public is largely unfamiliar and undecided about the practice. This study sheds light on how individuals may come to understand hydraulic fracturing as this unconventional production technology becomes more prominent in the United States. For the study, a thorough search of HF photographs was performed, and a systematic evaluation of 40 images using an online experimental design involving N = 250 participants was conducted. Key indicators of hydraulic fracturing support and beliefs were identified. Participants showed diversity in their support for the practice, with 47 percent expressing low support, 22 percent high support, and 31 percent undecided. Support for HF was positively associated with beliefs that hydraulic fracturing is primarily an economic issue and negatively associated with beliefs that it is an environmental issue. Level of support was also investigated as a perceptual filter that facilitates biased issue perceptions and affective evaluations of economic benefit and environmental cost frames presented in visual content of hydraulic fracturing. Results suggested an interactive relationship between visual framing and level of support, pointing to a substantial barrier to common understanding about the issue that strategic communicators should consider.

  8. Birth of a hydraulic jump (United States)

    Duchesne, Alexis; Bohr, Tomas; Andersen, Anders


    The hydraulic jump, i.e., the sharp transition between a supercritical and a subcritical free-surface flow, has been extensively studied in the past centuries. However, ever since Leonardo da Vinci asked it for the first time, an important question has been left unanswered: How does a hydraulic jump form? We present an experimental and theoretical study of the formation of stationary hydraulic jumps in centimeter wide channels. Two starting situations are considered: The channel is, respectively, empty or filled with liquid, the liquid level being fixed by the wetting properties and the boundary conditions. We then change the flow-rate abruptly from zero to a constant value. In an empty channel, we observe the formation of a stationary hydraulic jump in a two-stage process: First, the channel fills by the advancing liquid front, which undergoes a transition from supercritical to subcritical at some position in the channel. Later the influence of the downstream boundary conditions makes the jump move slowly upstream to its final position. In the pre-filled channel, the hydraulic jump forms at the injector edge and then moves downstream to its final position.

  9. Aseismic and seismic slip induced by fluid injection from poroelastic and rate-state friction modeling (United States)

    Liu, Y.; Deng, K.; Harrington, R. M.; Clerc, F.


    Solid matrix stress change and pore pressure diffusion caused by fluid injection has been postulated as key factors for inducing earthquakes and aseismic slip on pre-existing faults. In this study, we have developed a numerical model that simulates aseismic and seismic slip in a rate-and-state friction framework with poroelastic stress perturbations from multi-stage hydraulic fracturing scenarios. We apply the physics-based model to the 2013-2015 earthquake sequences near Fox Creek, Alberta, Canada, where three magnitude 4.5 earthquakes were potentially induced by nearby hydraulic fracturing activity. In particular, we use the relocated December 2013 seismicity sequence to approximate the fault orientation, and find the seismicity migration spatiotemporally correlate with the positive Coulomb stress changes calculated from the poroelastic model. When the poroelastic stress changes are introduced to the rate-state friction model, we find that slip on the fault evolves from aseismic to seismic in a manner similar to the onset of seismicity. For a 15-stage hydraulic fracturing that lasted for 10 days, modeled fault slip rate starts to accelerate after 3 days of fracking, and rapidly develops into a seismic event, which also temporally coincides with the onset of induced seismicity. The poroelastic stress perturbation and consequently fault slip rate continue to evolve and remain high for several weeks after hydraulic fracturing has stopped, which may explain the continued seismicity after shut-in. In a comparison numerical experiment, fault slip rate quickly decreases to the interseismic level when stress perturbations are instantaneously returned to zero at shut-in. Furthermore, when stress perturbations are removed just a few hours after the fault slip rate starts to accelerate (that is, hydraulic fracturing is shut down prematurely), only aseismic slip is observed in the model. Our preliminary results thus suggest the design of fracturing duration and flow

  10. Stochastic joint inversion of hydrogeophysical data for salt tracer test monitoring and hydraulic conductivity imaging (United States)

    Jardani, A.; Revil, A.; Dupont, J. P.


    The assessment of hydraulic conductivity of heterogeneous aquifers is a difficult task using traditional hydrogeological methods (e.g., steady state or transient pumping tests) due to their low spatial resolution. Geophysical measurements performed at the ground surface and in boreholes provide additional information for increasing the resolution and accuracy of the inverted hydraulic conductivity field. We used a stochastic joint inversion of Direct Current (DC) resistivity and self-potential (SP) data plus in situ measurement of the salinity in a downstream well during a synthetic salt tracer experiment to reconstruct the hydraulic conductivity field between two wells. The pilot point parameterization was used to avoid over-parameterization of the inverse problem. Bounds on the model parameters were used to promote a consistent Markov chain Monte Carlo sampling of the model parameters. To evaluate the effectiveness of the joint inversion process, we compared eight cases in which the geophysical data are coupled or not to the in situ sampling of the salinity to map the hydraulic conductivity. We first tested the effectiveness of the inversion of each type of data alone (concentration sampling, self-potential, and DC resistivity), and then we combined the data two by two. We finally combined all the data together to show the value of each type of geophysical data in the joint inversion process because of their different sensitivity map. We also investigated a case in which the data were contaminated with noise and the variogram unknown and inverted stochastically. The results of the inversion revealed that incorporating the self-potential data improves the estimate of hydraulic conductivity field especially when the self-potential data were combined to the salt concentration measurement in the second well or to the time-lapse cross-well electrical resistivity data. Various tests were also performed to quantify the uncertainty in the inverted hydraulic conductivity

  11. Integrated hydraulic booster/tool string technology for unfreezing of stuck downhole strings in horizontal wells (United States)

    Tian, Q. Z.


    It is common to use a jarring tool to unfreeze stuck downhole string. However, in a horizontal well, influenced by the friction caused by the deviated section, jarring effect is poor; on the other hand, the forcing point can be located in the horizontal section by a hydraulic booster and the friction can be reduced, but it is time-consuming and easy to break downhole string using a large-tonnage and constant pull force. A hydraulic booster - jar tool string has been developed for unfreezing operation in horizontal wells. The technical solution involves three elements: a two-stage parallel spring cylinder structure for increasing the energy storage capacity of spring accelerators; multiple groups of spring accelerators connected in series to increase the working stroke; a hydraulic booster intensifying jarring force. The integrated unfreezing tool string based on these three elements can effectively overcome the friction caused by a deviated borehole, and thus unfreeze a stuck string with the interaction of the hydraulic booster and the mechanical jar which form an alternatively dynamic load. Experimental results show that the jarring performance parameters of the hydraulic booster-jar unfreezing tool string for the horizontal wells are in accordance with original design requirements. Then field technical parameters were developed based on numerical simulation and experimental data. Field application shows that the hydraulic booster-jar unfreezing tool string is effective to free stuck downhole tools in a horizontal well, and it reduces hook load by 80% and lessens the requirement of workover equipment. This provides a new technology to unfreeze stuck downhole string in a horizontal well.

  12. Numerical Modeling of Freezing and Melting Processes around a Borehole Heat Exchanger (United States)

    Shao, Haibing; Zheng, Tianyuan; Nagel, Thomas; Kolditz, Olaf


    In ground sourced heat pump (GSHP) systems, heat energy stored in the shallow subsurface is extracted through borehole heat exchangers (BHE) and then utilized for domestic heating. In cold regions, the continuous heat deficit in the vicinity of the BHE can cause freezing of the surrounding soil. Its material properties, such as permeability and heat conductivity, will then significantly change and lead to a series of coupled thermal, hydraulic, and mechanical processes. In particular, the heat exchange performance of the BHE will be altered, and the frozen soil may also induce ground lift or subsidence in the vicinity of the building. As the first step of modelling this coupled system, we followed the approach proposed by Al-Khoury et al (2010) and Diersch et al (2011), where the BHE has been fully integrated into the numerical model in a dual-continuum way. Additionally, we extended the existing heat transport module in the numerical simulator OpenGeoSys to include the freezing and melting processes, whereas the ice volume fraction in the soil is non-linearly dependent on the temperature, and the soil properties were determined based on the degree of freezing/melting. The non-linearity of the coupled model was numerically solved by a Newton scheme. The extended model has been verified by comparing numerical results against analytical solutions and also findings from other numerical codes. Moreover, we proposed and simulated a hypothetical scenario, where ice is gradually forming around a BHE in response to the continuous operation of a heat pump. The model is capable of reproducing the thermodynamic freezing process as well as the heat transport affected by it. Future work will be focused on the integration of deformation processes into the model.

  13. Borehole geophysical logging and aquifer-isolation tests conducted in well MG-1693 at North Penn Area 5 Superfund Site near Colmar, Montgomery County, Pennsylvania (United States)

    Bird, Philip H.


    hydraulic connection outside the borehole with intervals above and below the isolated interval. The specific capacities of intervals 9, 11, 12, and 13 were similar—2.12, 2.17, 3.09, and 3.08 (gal/min)/ft, respectively. The aquifer-isolation tests indicate that wells MG-1693 (NP-87) and MG-924 (NP-21) are connected primarily through the high-angle fracture from 416 to 435 ft bls. Pumping in either of these wells directly impacts the other well, allowing the pumped well to draw from water-bearing zones in the nonpumped well that are not present in or are not connected directly to the pumped well. The two boreholes act as a single, U-shaped well. The aquifer-isolation tests also show that the lower zones in well MG-1693 (NP-87) are a major source of hydraulic head in well MG-1661 (W-13) through the broken casing joint at 82 ft bls. Water moving upward from the lower intervals in well MG-1693 (NP-87) exits the borehole through the broken casing joint, moves upward outside the borehole, possibly around and (or) through a poor or damaged casing seal, and through the weathered zone above bedrock to well MG-1661 (W-13).Samples for volatile organic compounds (VOCs) were collected in nine isolated intervals. Six compounds were detected (1,1-dichloroethane, 1,1-dichloroethene, cis-1,2-dichloroethene, toluene, 1,1,1-trichloroethane, and trichloroethene (TCE)), and TCE was found in all nine isolated intervals. Intervals 4 (124-149 ft bls) and 6 (277-302 ft bls) had the highest total concentration of VOCs (6.66 and 6.2 micrograms per liter, respectively). Intervals 1 (68-93 ft bls) and 4 each had five compounds detected, which was the highest number of compounds detected. Interval 5 (252-277 ft bls) had the lowest total concentration of VOCs (0.08 microgram per liter) and the least number of VOCs detected (one). Detected compounds were not evenly distributed throughout the intervals. Contaminants were found in shallow, intermediate, and deep intervals and were associated with high

  14. BUILDING 341 Seismic Evaluation

    Energy Technology Data Exchange (ETDEWEB)

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


    The Seismic Evaluation of Building 341 located at Lawrence Livermore National Laboratory in Livermore, California has been completed. The subject building consists of a main building, Increment 1, and two smaller additions; Increments 2 and 3.

  15. Seismic Creep, USA Images (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Seismic creep is the constant or periodic movement on a fault as contrasted with the sudden rupture associated with an earthquake. It is a usually slow deformation...

  16. Electrokinetic high pressure hydraulic system (United States)

    Paul, Phillip H.; Rakestraw, David J.; Arnold, Don W.; Hencken, Kenneth R.; Schoeniger, Joseph S.; Neyer, David W.


    An electrokinetic high pressure hydraulic pump for manipulating fluids in capillary-based systems. The pump uses electro-osmotic flow to provide a high pressure hydraulic system, having no moving mechanical parts, for pumping and/or compressing fluids, for providing valve means and means for opening and closing valves, for controlling fluid flow rate, and manipulating fluid flow generally and in capillary-based systems (Microsystems), in particular. The compact nature of the inventive high pressure hydraulic pump provides the ability to construct a micro-scale or capillary-based HPLC system that fulfills the desire for small sample quantity, low solvent consumption, improved efficiency, the ability to run samples in parallel, and field portability. Control of pressure and solvent flow rate is achieved by controlling the voltage applied to an electrokinetic pump.

  17. Complex Fluids and Hydraulic Fracturing. (United States)

    Barbati, Alexander C; Desroches, Jean; Robisson, Agathe; McKinley, Gareth H


    Nearly 70 years old, hydraulic fracturing is a core technique for stimulating hydrocarbon production in a majority of oil and gas reservoirs. Complex fluids are implemented in nearly every step of the fracturing process, most significantly to generate and sustain fractures and transport and distribute proppant particles during and following fluid injection. An extremely wide range of complex fluids are used: naturally occurring polysaccharide and synthetic polymer solutions, aqueous physical and chemical gels, organic gels, micellar surfactant solutions, emulsions, and foams. These fluids are loaded over a wide range of concentrations with particles of varying sizes and aspect ratios and are subjected to extreme mechanical and environmental conditions. We describe the settings of hydraulic fracturing (framed by geology), fracturing mechanics and physics, and the critical role that non-Newtonian fluid dynamics and complex fluids play in the hydraulic fracturing process.

  18. Hydraulic properties of ladle slags

    Directory of Open Access Journals (Sweden)

    J. Vlček


    Full Text Available The article presents results of examining of hydraulic properties of ladle slags formed during production of steel. The studied ladle slags were subjected to different cooling mode from the molten state. Based on the ability of the slag react with the water was assessed their hydraulic activity. The hydraulic properties are caused by the presence of minerals dicalcium silicate, tricalcium aluminate, mayenite, brownmillerite and dicalcium ferite. The emergence of required hydrating phases in the ladle slags is conditioned by a sufficient CaO content and their cooling rate. The contact the slag with water during processing and their ageing has a negative effect. The experiment has shown that the phase transformation of the mineral dicalcium silicate which occurs during cooling of the ladle slags cause their volume instability.

  19. Issues Related to Seismic Activity Induced by the Injection of CO2 in Deep Saline Aquifers

    Energy Technology Data Exchange (ETDEWEB)

    Sminchak, Joel [Battelle Memorial Institute, Columbus, OH (US); Gupta, Neeraj [Battelle Memorial Institute, Columbus, OH (US); Byrer, Charles [National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV (US); Bergman, Perry [National Energy Technology Laboratory, Pittsburgh, PA, and Morgantown, WV (US)


    Case studies, theory, regulation, and special considerations regarding the disposal of carbon dioxide (CO2) into deep saline aquifers were investigated to assess the potential for induced seismic activity. Formations capable of accepting large volumes of CO2 make deep well injection of CO2 an attractive option. While seismic implications must be considered for injection facilities, induced seismic activity may be prevented through proper siting, installation, operation, and monitoring. Instances of induced seismic activity have been documented at hazardous waste disposal wells, oil fields, and other sites. Induced seismic activity usually occurs along previously faulted rocks and may be investigated by analyzing the stress conditions at depth. Seismic events are unlikely to occur due to injection in porous rocks unless very high injection pressures cause hydraulic fracturing. Injection wells in the United States are regulated through the Underground Injection Control (UIC) program. UIC guidance requires an injection facility to perform extensive characterization, testing, and monitoring. Special considerations related to the properties of CO2 may have seismic ramifications to a deep well injection facility. Supercritical CO2 liquid is less dense than water and may cause density-driven stress conditions at depth or interact with formation water and rocks, causing a reduction in permeability and pressure buildup leading to seismic activity. Structural compatibility, historical seismic activity, cases of seismic activity triggered by deep well injection, and formation capacity were considered in evaluating the regional seismic suitability in the United States. Regions in the central, midwestern, and southeastern United States appear best suited for deep well injection. In Ohio, substantial deep well injection at a waste disposal facility has not caused seismic events in a seismically active area. Current

  20. The availability of hydrogeologic data associated with areas identified by the US Geological Survey as experiencing potentially induced seismicity resulting from subsurface injection (United States)

    Barnes, Caitlin; Halihan, Todd


    A critical need exists for site-specific hydrogeologic data in order to determine potential hazards of induced seismicity and to manage risk. By 2015, the United States Geological Survey (USGS) had identified 17 locations in the USA that are experiencing an increase in seismicity, which may be potentially induced through industrial subsurface injection. These locations span across seven states, which vary in geological setting, industrial exposure and seismic history. Comparing the research across the 17 locations revealed patterns for addressing induced seismicity concerns, despite the differences between geographical locations. Most induced seismicity studies evaluate geologic structure and seismic data from areas experiencing changes in seismic activity levels, but the inherent triggering mechanism is the transmission of hydraulic pressure pulses. This research conducted a systematic review of whether data are available in these locations to generate accurate hydrogeologic predictions, which could aid in managing seismicity. After analyzing peer-reviewed research within the 17 locations, this research confirms a lack of site-specific hydrogeologic data availability for at-risk areas. Commonly, formation geology data are available for these sites, but hydraulic parameters for the seismically active injection and basement zones are not available to researchers conducting peer-reviewed research. Obtaining hydrogeologic data would lead to better risk management for injection areas and provide additional scientific evidential support for determining a potentially induced seismic area.

  1. Hydraulic resistance of biofilms

    KAUST Repository

    Dreszer, C.


    Biofilms may interfere with membrane performance in at least three ways: (i) increase of the transmembrane pressure drop, (ii) increase of feed channel (feed-concentrate) pressure drop, and (iii) increase of transmembrane passage. Given the relevance of biofouling, it is surprising how few data exist about the hydraulic resistance of biofilms that may affect the transmembrane pressure drop and membrane passage. In this study, biofilms were generated in a lab scale cross flow microfiltration system at two fluxes (20 and 100Lm-2h-1) and constant cross flow (0.1ms-1). As a nutrient source, acetate was added (1.0mgL-1 acetate C) besides a control without nutrient supply. A microfiltration (MF) membrane was chosen because the MF membrane resistance is very low compared to the expected biofilm resistance and, thus, biofilm resistance can be determined accurately. Transmembrane pressure drop was monitored. As biofilm parameters, thickness, total cell number, TOC, and extracellular polymeric substances (EPS) were determined, it was demonstrated that no internal membrane fouling occurred and that the fouling layer actually consisted of a grown biofilm and was not a filter cake of accumulated bacterial cells. At 20Lm-2h-1 flux with a nutrient dosage of 1mgL-1 acetate C, the resistance after 4 days reached a value of 6×1012m-1. At 100Lm-2h-1 flux under the same conditions, the resistance was 5×1013m-1. No correlation of biofilm resistance to biofilm thickness was found; Biofilms with similar thickness could have different resistance depending on the applied flux. The cell number in biofilms was between 4×107 and 5×108 cellscm-2. At this number, bacterial cells make up less than a half percent of the overall biofilm volume and therefore did not hamper the water flow through the biofilm significantly. A flux of 100Lm-2h-1 with nutrient supply caused higher cell numbers, more biomass, and higher biofilm resistance than a flux of 20Lm-2h-1. However, the biofilm thickness

  2. Estimation of barometric pressure response in borehole strainmeter with typhoon events in Taiwan (United States)

    Chiu, Chun-Ying; Hu, Jyr-Ching; Liu, Chi-Ching


    Taiwan is located in an active collisional boundary of Philippine Sea plate and Eurasian plate in a convergence rate of 82 mm/yr, which results in high frequent seismicity and destructive big earthquakes. In order to monitor the strain change from pre-slip events, 13 Gladwin Tensor Strainmeters (GTSM) were installed in a depth of 200 m in western Foothills of Taiwan since 2003. The previous studies demonstrated that the broad environmental signs of barometry, rainfall, tide and groundwater should be calibrated to detect the tectonic signal. The previous study from borehole strainmeter of PBO in western US suggested that the strainmeter gauge time series were divided into records of approximately 60 days, overlapping when possible by 30 days. In order to determine the barometric pressure response of each gauge, the gauge outputs and atmospheric pressure data were band-pass-filtered to exclude frequencies outside the 4-6 day band. The results showed that sixty day records had a good correlation between the atmospheric pressure and the strainmeter gauge time series. Due to the climatic characteristics of annual rainfall could reach to 2500 mm in Taiwan, the long duration of gauge time series will be distributed by rainfall signal. Thus we suggest to divide the gauge time series records of approximately 30 days, overlapping when possible by 5 days. A good correlation of between the atmospheric pressure and the strainmeter gauge time series were identified by using a band-pass-filtered to exclude frequencies outside the 3-7 day band. In addition, we can use the linear regression from gauge time series and barometric drop due to the before the typhoon events with no interference of rainfall events. The average atmospheric pressure response coefficients of the strainmeters are about -0.14 -0.38 µstrain/KPa.

  3. Tidal modulation of slow slip events in the Nankai trough subduction zone detected by borehole strainmeters (United States)

    Kikuchi, J.; Ide, S.; Matsumoto, N.


    Slow slip events (SSEs) often occur in the Nankai subduction zone, Japan, within a band-like zone extended from the center of Honshu to western Shikoku. SSEs are believed as shear slip on the plate interface, where the frictional property changes from velocity weakening to strengthening in the dip direction. Therefore the dynamics of SSEs may give some hints on the depth dependent friction and plate subduction. The tidal modulation of SSEs has been identified by statistical analysis using strain data of Plate Boundary Observatory, in the Cascadia subduction zone [Hawthorne & Rubin, 2010]. Here, we perform similar statistical analyses using strain data recorded at borehole stations maintained by National Institute of Advanced Industrial Science and Technology, in western Japan. The correlation between the oscillation in SSEs and tidal stress was confirmed statistically. In Nankai subduction zone, it is known that SSEs are accompanied with high activity of deep tectonic tremors [Hirose & Obara, 2006]. These tremors have been known to be sensitive to tidal stress [Nakata et al., 2008]. Therefore, the tidal modulation of SSEs is another representation of tidal modulation of tremors. To clarify the relation between SSEs and tremors, we investigate whether strain changes corresponding to SSEs can be explained only by tremors activity. For an SSE occurred in Aug. 2010 in Bungo channel, we assume that the seismic moment of the SSE is 1.6 × 1018 Nm (Mw 6.1) based on the inversion of GNSS data [Nishimura et al., 2013], and that this moment is released by 715 tremors that occur during this SSE [Idehara et al., 2014]. In this case, each tremor is assigned with seismic moment of 2.2 × 1015 Nm (Mw 4.2). Then the strain change at the observation station by these tremors is calculated using the Okada [1992] method, assuming a half space and focal mechanism consistent with the regional plate motion. The calculated strain is qualitatively similar with the observed strain

  4. Upper Mississippi embayment shallow seismic velocities measured in situ (United States)

    Liu, Huaibao P.; Hu, Y.; Dorman, J.; Chang, T.-S.; Chiu, J.-M.


    Vertical seismic compressional- and shear-wave (P- and S-wave) profiles were collected from three shallow boreholes in sediment of the upper Mississippi embayment. The site of the 60-m hole at Shelby Forest, Tennessee, is on bluffs forming the eastern edge of the Mississippi alluvial plain. The bluffs are composed of Pleistocene loess, Pliocene-Pleistocene alluvial clay and sand deposits, and Tertiary deltaic-marine sediment. The 36-m hole at Marked Tree, Arkansas, and the 27-m hole at Risco, Missouri, are in Holocene Mississippi river floodplain sand, silt, and gravel deposits. At each site, impulsive P- and S-waves were generated by man-made sources at the surface while a three-component geophone was locked downhole at 0.91-m intervals. Consistent with their very similar geology, the two floodplain locations have nearly identical S-wave velocity (VS) profiles. The lowest VS values are about 130 m s-1, and the highest values are about 300 m s-1 at these sites. The shear-wave velocity profile at Shelby Forest is very similar within the Pleistocene loess (12m thick); in deeper, older material, VS exceeds 400 m s-1. At Marked Tree, and at Risco, the compressional-wave velocity (VP) values above the water table are as low as about 230 m s-1, and rise to about 1.9 km s-1 below the water table. At Shelby Forest, VP values in the unsaturated loess are as low as 302 m s-1. VP values below the water table are about 1.8 km s-1. For the two floodplain sites, the VP/VS ratio increases rapidly across the water table depth. For the Shelby Forest site, the largest increase in the VP/VS ratio occurs at ???20-m depth, the boundary between the Pliocene-Pleistocene clay and sand deposits and the Eocene shallow-marine clay and silt deposits. Until recently, seismic velocity data for the embayment basin came from earthquake studies, crustal-scale seismic refraction and reflection profiles, sonic logs, and from analysis of dispersed earthquake surface waves. Since 1991, seismic data

  5. Seismic Modeling of the Alasehir Graben, Western Turkey (United States)

    Gozde Okut, Nigar; Demirbag, Emin


    The purpose of this study is to develop a depth model to make synthetic seismic reflection sections, such as stacked and migrated sections with different velocity models. The study area is east-west trending Alasehir graben which is one of the most prominent structure in the western Anatolia, proved to have geothermal energy potential by researchers and exploration companies. Geological formations were taken from Alaşehir-1 borehole drilled by Turkish Petroleum Corporation (Çiftçi, 2007) and seismic interval velocities were taken from check-shots in the same borehole (Kolenoǧlu-Demircioǧlu, 2009). The most important structure is the master graben bounding fault (MGBF) in the southern margin of the Alasehir graben. Another main structure is the northern bounding fault called the antithetic fault of the MGBF with high angle normal fault characteristic. MGBF is a crucial contact between sedimentary cover and the metamorphic basement. From basement to the surface, five different stratigraphic units constitute graben fill . All the sedimentary units thicknesses get thinner from the southern margin to the northern margin of the Alasehir graben displaying roll-over geometry. A commercial seismic data software was used during modeling. In the first step, a 2D velocity/depth model was defined. Ray tracing was carried out with diffraction option to produce the reflection travel times. The reflection coefficients were calculated and wavelet shaping was carried out by means of band-pass filtering. Finally synthetic stacked section of the Alasehir graben was obtained. Then, migrated sections were generated with different velocity models. From interval velocities, average and RMS velocities were calculated for the formation entires to test how the general features of the geological model may change against different seismic models after the migration. Post-stack time migration method was used. Pseudo-velocity analysis was applied at selected CDP locations. In theory

  6. Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross


    The primary purpose of this model report is to develop abstractions for the response of engineered barrier system (EBS) components to seismic hazards at a geologic repository at Yucca Mountain, Nevada, and to define the methodology for using these abstractions in a seismic scenario class for the Total System Performance Assessment - License Application (TSPA-LA). A secondary purpose of this model report is to provide information for criticality studies related to seismic hazards. The seismic hazards addressed herein are vibratory ground motion, fault displacement, and rockfall due to ground motion. The EBS components are the drip shield, the waste package, and the fuel cladding. The requirements for development of the abstractions and the associated algorithms for the seismic scenario class are defined in ''Technical Work Plan For: Regulatory Integration Modeling of Drift Degradation, Waste Package and Drip Shield Vibratory Motion and Seismic Consequences'' (BSC 2004 [DIRS 171520]). The development of these abstractions will provide a more complete representation of flow into and transport from the EBS under disruptive events. The results from this development will also address portions of integrated subissue ENG2, Mechanical Disruption of Engineered Barriers, including the acceptance criteria for this subissue defined in Section of the ''Yucca Mountain Review Plan, Final Report'' (NRC 2003 [DIRS 163274]).

  7. Interim reclamation report, Basalt Waste Isolation project: Boreholes, 1989

    Energy Technology Data Exchange (ETDEWEB)

    Brandt, C.A.; Rickard, W.H. Jr.; Hefty, M.G.


    In 1968, a program was started to assess the feasibility of storing Hanford Site defense waste in deep caverns constructed in basalt. This program was expanded in 1976 to include investigations of the Hanford Site as a potential location for a mined commercial nuclear waste repository. An extensive site characterization program was begun to determine the feasibility of using the basalts beneath the Hanford Site for the repository. Site research focused primarily on determining the direction and speed of groundwater movement, the uniformity of basalt layers, and tectonic stability. Some 98 boreholes were sited, drilled, deepened, or modified by BWIP between 1977 and 1988 to test the geologic properties of the Site. On December 22, 1987, President Reagan signed into law the Nuclear Waste Policy Amendments Act of 1987, which effectively stopped all repository-related activities except reclamation of disturbed lands at the Hanford Site. This report describes the development of the reclamation program for the BWIP boreholes, its implementation, and preliminary estimates of its success. The goal of the reclamation program is to return sites disturbed by the repository program as nearly as practicable to their original conditions using native plant species. 48 refs., 28 figs., 14 tabs.

  8. Resolving the Younger Dryas Event Through Borehole Thermometry (United States)

    Firestone, John Francis

    One of the most striking features of the ice core records from Greenland is a sudden drop in oxygen isotope values (delta O-18) between approximately 11,500 and 10,700 years ago. This Younger Dryas event was an intense return to ice age conditions during a time of general de-glaciation. As recorded in the ice cores, temperatures in Greenland cooled by roughly seven degrees Kelvin. W. Broecker and R. Fairbanks have proposed competing explanations for the cooling and cause of this "aborted ice age." One supposes that the seven degree cooling is real and results from a shutdown in the North Atlantic ocean circulation; the other, that it is largely fictitious and records an intrusion of isotopically light glacial meltwater into the ice core records. Using optimal control methods and heat flow modelling, the author makes a valiant but ultimately futile attempt to distinguish the Younger Dryas event in the ice sheet temperatures measured at Dye 3, South Greenland. The author discusses the prospects for attempting the same in the new Summit boreholes in Central Greenland: how that will require more accurate temperature measurements, a coupled thermo-mechanical model, and a refined uncertainty analysis. He concludes by discussing how borehole temperature analysis may improve the climate histories determined from ice cores.

  9. Sapropelite from the Dzikowiec IG borehole section (intrasudetic depression)

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, G.J. (Panstwowy Instytut Geologiczny (Poland). Oddzial Dolnoslaski)


    Characterizes the coal deposit in the area of Nowa Ruda (Lower Silesia coal basin) in Poland. Results of the IG 1 exploratory borehole drilled to a depth of 1,800 m at the site of Dzikowiec are given. The lithostratigraphic profile of the borehole, locating the coal seam in 1,279 m depth, is shown. Petrographic and microscopic characteristics of the coal seam, composed of vitrinite, exinite, fusinite and inertinite, are pointed out, as well the sapropelic character of the coal. Due to sporinite domination, the coal is classified as spore cannel. Conclusions on coal genesis are made: the low vitrinite content and spore character prove that organic matter accumulation took place under shallow water. The high amount of syngenetic coal pyrite suggests that accumulation occurred in a neutral or alkaline environment (pH 6.5-8). Besides pyrite, other inorganic components are clay minerals, carbonates and quartz. Petrographic results support the allochthonous origin of the coal deposit. 21 refs.

  10. Borehole sealing. Final report, March 1, 1973--October 31, 1973

    Energy Technology Data Exchange (ETDEWEB)

    Eilers, L.H.


    A program to evaluate existing materials and techniques to permanently plug boreholes penetrating salt strata near prospective radioactive waste depository sites is described. A new subcontract No. 78X-33542C has been issued to seal a borehole near Lyons, Kansas, using the materials and techniques recommended in this report. It is recommended that the well be thoroughly cleaned including removing any casing penetrating the critical salt strata. Following this, any fluid-bearing zones should be grouted using the best grout available. Silica gel was recommended for porous zones backed up by Portland cement to seal fractures and vugs. Recommendations were made to use sulfate resistant Chem Comp or sulfate resistant regular Portland (Type V) as the primary sealing material in the areas where anhydrite strata are present such as the existing wells at Lyons, Kansas, or the prospective wells near Carlsbad, New Mexico. This would be modified to meet existing conditions such as salt saturated slurry through the salt strata or added powdered silica in the zones which might exceed 230/sup 0/F at any time. A short epoxy plug was recommended at the top and bottom of the salt strata and a short Seal Ring plug at the base of any extensive water zones. Extensive water zones are not expected in the New Mexico area, however.

  11. Method for hydraulically fracturing strata

    Energy Technology Data Exchange (ETDEWEB)

    Petryashin, L.F.; Zheltoukhov, V.V.


    The proposed method for the hydraulic fracture of strata involves the input of ground magnesium and an inert substance in the bore hole, the latter being pumped under pressure into the strata. In order to improve the quality of the fracture, crystallized chloroacetic acid is used. This acid, prior to its injection into the bore hole, is mixed with the magnesium and starch. This method allows hydraulic fracturing to be conducted in a simpler, more economical, more effective manner as well as in intervals.

  12. Controls of Hydraulic Wind Turbine

    Directory of Open Access Journals (Sweden)

    Zhang Yin


    Full Text Available In this paper a hydraulic wind turbine generator system was proposed based on analysis the current wind turbines technologies. The construction and principles were introduced. The mathematical model was verified using MATLAB and AMsim. A displacement closed loop of swash plate of motor and a speed closed loop of generator were setup, a PID control is introduced to maintain a constant speed and fixed frequency at wind turbine generator. Simulation and experiment demonstrated that the system can connect grid to generate electric and enhance reliability. The control system demonstrates a high performance speed regulation and effectiveness. The results are great significant to design a new type hydraulic wind turbine system.

  13. Long-term decay and possible reactivation of induced seismicity at the Basel EGS site (United States)

    Kraft, Toni; Herrmann, Marcus; Karvounis, Dimitrios; Tormann, Thessa; Deichmann, Nicolas; Wiemer, Stefan


    In December 2006, an extensive fluid injection was carried out below the city of Basel, Switzerland, to stimulate a reservoir for an Enhanced Geothermal System (EGS). After six days of gradual increase of flow rate (and thus seismicity), a strongly felt ML3.4 earthquakes led to the immediate termination of the project. The well was opened subsequently and seismicity declined rapidly. The Basel EGS project might be an unsuccessful attempt in terms of energy supply, but a chance to advance the physical understanding of EGSs. The well-monitored and well-studied induced sequence allowed many new insights in terms of reservoir creation. A special observation in the nine years of monitoring is the revive of seismic activity six years after prolonged seismic decay. This renewed activity increase might relate to a gradual pressure increase due to the ultimate shut-in (closure) of the borehole about one year before. Until now, a detailed analysis of the long-term behaviour remained unexplored since a consistent catalogue did not exist. In the current study, we took advantage of the high waveform similarity within a seismic sequence and applied a multi-trace template-matching (i.e. cross-correlation) procedure to detect seismic events about one order of magnitude below the detection threshold. We detected about 100,000 events within the six-day long stimulation alone - previously, only 13,000 microearthquakes were detected. We only scanned the recordings of the deepest borehole station (2.7km). This station is very close to the 5km-deep reservoir and has the highest signal-to-noise ratio among all (borehole-)stations. Our newly obtained catalogue spans over more than nine years and features a uniform (and low) detection threshold and a uniform magnitude determination. The improved resolution of the long-term behaviour and the later seismicity increase will help to understand involved mechanisms better. More induced or natural sequences can be investigated with our procedure.

  14. Sequential Data Assimilation for Seismicity: a Proof of Concept (United States)

    van Dinther, Ylona; Kuensch, Hans Rudolf; Fichtner, Andreas


    Integrating geological and geophysical observations, laboratory results and physics-based numerical modeling is crucial to improve our understanding of the occurrence of large subduction earthquakes. How to do this integration is less obvious, especially in light of the scarcity and uncertainty of natural and laboratory data and the difficulty of modeling the physics governing earthquakes. One way to efficiently combine information from these sources in order to estimate states and/or parameters is data assimilation, a mathematically sound framework extensively developed for weather forecasting purposes. We demonstrate the potential of using data assimilation by applying an Ensemble Kalman Filter to recover the current and forecast the future state of stress and strength on the megathrust based on data from a single borehole. Data and its errors are for the first time assimilated to - using the least-squares solution of Bayes theorem - update a Partial Differential Equation-driven seismic cycle model. This visco-elasto-plastic continuum forward model solves Navier-Stokes equations with a rate-dependent friction coefficient. To prove this concept we perform a perfect model test in an analogue subduction zone setting. Synthetic numerical data from a single analogue borehole are assimilated into 150 ensemble models. Since we know the true state of the numerical data model, a quantitative and qualitative evaluation shows that meaningful information on the stress and strength is available, even when only data from a single borehole is assimilated over only a part of a seismic cycle. This is possible, since the sampled error covariance matrix contains prior information on the physics that relates velocities, stresses, and pressures at the surface to those at the fault. During the analysis step, stress and strength distributions are thus reconstructed in such a way that fault coupling can be updated to either inhibit or trigger events. In the subsequent forward

  15. Characterization of borehole fractures by the body and interface waves

    NARCIS (Netherlands)

    Henry, F.


    The success of the fracturing process in the oil and gas industry depends on our ability to define the hydraulic fracture geometry. To have a method of measurement for characterizing completely the fracture dimensions from a single well in reliable way, will be a primordial importance, in term of

  16. Integrating hydraulic equivalent sections into a hydraulic geometry study (United States)

    Jia, Yanhong; Yi, Yujun; Li, Zhiwei; Wang, Zhaoyin; Zheng, Xiangmin


    Hydraulic geometry (HG) is an important geomorphic concept that has played an indispensable role in hydrological analyses, physical studies of streams, ecosystem and aquatic habitat studies, and sedimentology research. More than 60 years after Leopold and Maddock (1953) first introduced the concept of HG, researchers have still not uncovered the physical principles underlying HG behavior. One impediment is the complexity of the natural river cross section. The current study presents a new way to simplify the cross section, namely, the hydraulic equivalent section, which is generalized from the cross section in the "gradually varied flow of an alluvial river" (GVFAR) and features hydrodynamic properties and bed-building laws similar to those of the GVFAR. Energy balance was used to derive the stage Z-discharge Q relationship in the GVFAR. The GVFAR in the Songhua River and the Yangtze River were selected as examples. The data, including measured discharge, river width, water stage, water depth, wet area, and cross section, were collected from the hydrological yearbooks of typical hydrological stations on the Songhua River and the Yangtze River from 1955 to 1987. The relationships between stage Z-discharge Q and cross-sectional area A-stage Z at various stations were analyzed, and "at-a-station hydraulic geometry" (AHG) relationships were obtained in power-law forms. Based on derived results and observational data analysis, the Z-Q and Z-A relationships of AHG were similar to rectangular weir flows, thus the cross section of the GVFAR was generalized as a compound rectangular, hydraulic equivalent cross section. As to bed-building characteristics, the bankfull discharge method and the stage-discharge-relation method were used to calculate the dominant variables of the alluvial river. This hydraulic equivalent section has the same Z-Q relation, Z-A relation, dominant discharge, dominant river width, and dominant water depth as the cross section in the GVFAR. With the

  17. Hydraulic and hydrologic evaluation of PAR Pond Dam. Technical evaluation report

    Energy Technology Data Exchange (ETDEWEB)

    Reich, M.; Wang, P.C.; Khanbilvardi, R.; Bezler, P.


    The PAR Pond Dam at Savannah River Plant was constructed in 1958--1959. Seepage, depressions, boils and spring flow were observed in varying locations on the dam in the last few years. Comprehensive geotechnical and hydraulic investigations pertaining to the effects of the above observations on the abilities of the dam to withstand future floods were made in 1991 and early 1993 where dam capacity to survive flooding and seismic events were evaluated. Brookhaven National Laboratory (BNL) was asked by the Department of Energy (EH) to carry out an independent review of the PAR Pond Dam response to future flooding and seismic events. This report addresses the studies made to evaluate the capacity of the dam to survive floods. A companion report will summarize the evaluations performed to assess the seismic capacity of the dam.

  18. Hydro-mechanical modelling of induced seismicity during the deep geothermal project in St. Gallen, Switzerland (United States)

    Zbinden, Dominik; Rinaldi, Antonio Pio; Kraft, Toni; Diehl, Tobias; Wiemer, Stefan


    The St. Gallen deep geothermal project in 2013 was the second geothermal project in Switzerland with the objective of power production after the Enhanced Geothermal System in Basel in 2006. In St. Gallen, the seismic risk was expected to be smaller than in Basel, since the hydrothermal resource was an aquifer at a depth of about 4 km, not expected to require permeability enhancement and associated hydroshearing of the rock. However, after an injectivity test and two acid stimulations, unexpected gas release from an unidentified source forced the operators to inject drilling mud into the well to fight the gas kick. Subsequently, several seismic events were induced, the largest one having a local magnitude of 3.5, which was distinctly felt by the nearby living population. Even though the induced seismicity could not be handled properly, the community still strongly supported the geothermal project. The project was however halted because the target formation was not as permeable as required to deliver sufficient power. Still, controlling induced seismicity during deep geothermal projects is a key factor to successfully operate future geothermal projects. Hence, it is crucial to understand the physical relations of fluid injection, pressure and stress response at reservoir depth as well as associated induced seismicity. To date, these processes are yet not fully understood. In this study, we aim at developing a hydro-mechanical model reproducing the main features of the induced seismic sequence at the St. Gallen geothermal site. Here, we present the conceptual model and preliminary results accounting for hydraulic and mechanical parameters from the geothermal well, geological information from a seismic survey conducted in the St. Gallen region, and actual fluid injection rates from the injectivity tests. In a future step, we are going to use this model to simulate the physical interaction of injected fluid, gas release, hydraulic response of the rock, and induced

  19. Citizen Science Seismic Stations for Monitoring Regional and Local Events (United States)

    Zucca, J. J.; Myers, S.; Srikrishna, D.


    The earth has tens of thousands of seismometers installed on its surface or in boreholes that are operated by many organizations for many purposes including the study of earthquakes, volcanos, and nuclear explosions. Although global networks such as the Global Seismic Network and the International Monitoring System do an excellent job of monitoring nuclear test explosions and other seismic events, their thresholds could be lowered with the addition of more stations. In recent years there has been interest in citizen-science approaches to augment government-sponsored monitoring networks (see, for example, Stubbs and Drell, 2013). A modestly-priced seismic station that could be purchased by citizen scientists could enhance regional and local coverage of the GSN, IMS, and other networks if those stations are of high enough quality and distributed optimally. In this paper we present a minimum set of hardware and software specifications that a citizen seismograph station would need in order to add value to global networks. This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.

  20. Stress inversion using borehole images and geometry evolution of the fractures in the Rittershoffen EGS project (Alsace, France). (United States)

    Azzola, Jérôme; Valley, Benoît; Schmittbuhl, Jean; Genter, Albert; Hehn, Régis


    In the Upper Rhine Graben, several deep geothermal projects based on the Enhanced Geothermal System (EGS) exploit local geothermal reservoirs. The principle underlying this technology consists of increasing the hydraulic performances of the reservoir by stimulating natural fractures using different methods, in order to extract hot water with commercially flow rates. In this domain, the knowledge of the in-situ stress state is of central importance to predict the response of the rock mass to stimulations. Here we characterized the stress tensor from Ultrasonic Borehole Imager (UBI) in the open hole section of the EGS doublet located in Rittershoffen, France (in the Upper Rhine Graben). Interestingly extensive logging programs were leaded at different key moments of the development of the injection well using hydraulic, thermal and chemical stimulation (Baujard et al., 2017)1. The time lapse UBI dataset consists of images of the injection well before, shortly and lastly after the stimulation. The geometry of the induced fractures in compression (breakouts) picked on the UBI images are used to determine the orientation of the in-situ stress tensor. The magnitude of the principal stresses is deduced from the drilling data. The magnitude of the maximum horizontal principal stress is evaluated using an inversion method with three failure criteria (Mohr-Coulomb, Mogi-Coulomb and modified Hoek-Brown criterion) and under the assumption of a vertical or a deviated well. Moreover, the characteristic of the dataset enables the analysis of the evolution of the borehole fracturing, as the deepening or widening of the induced fractures. The correlation of the UBI image allows firstly to determine the tool trajectory and to adapt the post and pre-stimulation images. It secondly leads to the estimation of a complete displacement field which characterizes the deformation induced by the stimulations. Even if the variable image quality deeply conditions the comparison, the considered

  1. Borehole locations and top surface altitudes of each of the 16 hydrostratigraphic layers of the Atlantic Coastal Plain of North and South Carolina (pp1773_unit_alt_boreholes) (United States)

    U.S. Geological Survey, Department of the Interior — Point data pp1773_unit_alt_boreholes represent the 309 locations of various types of boreholes that were used to determine the altitudes of each of the 16...

  2. Surface waves in a cylindrical borehole through partially-saturated ...

    Indian Academy of Sciences (India)



    Jan 4, 2017 ... 1. Introduction. 40. The propagation of seismic waves in saturated porous media and related phenomena are of. 41 great interest in various fields, viz. acoustics, biomechanics, structural engineering, seismology. 42 and exploration of subsurface resources. Pores and fractures are pervasive in almost all the.

  3. Hydraulics submission for Middlesex County, NJ (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data include spatial datasets and data tables necessary for documenting the hydraulic procedures for estimating base flood elevation for a flood insurance...

  4. DCS Hydraulics Submittal, Butler County, Alabama, USA (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  5. DCS Hydraulics Submittal, Covington County, Alabama, USA (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computing flood elevations for a flood insurance...

  6. DCS Hydraulics Submittal, Bullock County, Alabama, USA (United States)

    Federal Emergency Management Agency, Department of Homeland Security — Hydraulics data includes spatial datasets and data tables necessary for documenting the hydraulic procedures for computin