WorldWideScience

Sample records for well logging

  1. Well Logging Symposium News

    Institute of Scientific and Technical Information of China (English)

    Yang Chunsheng

    1996-01-01

    @@ ‘96 International Symposium on Well Logging Techniques for Oilfield Development under Waterflood was held on 17-21 September, 1996 in Beijing. The symdrew than 160 experts and scholars in the well logging circle from Russia,The United States, France, Britain, Indonesia and China. About 80 papers were presented duringthe symposium. Mr. Zhang Yongyi,Vice President of CNPC delivered the opening remarks.

  2. CCSD Well Logging Engineering Program

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    This paper introduces briefly the tasks and characteristics of China Continent Science Drilling (CCSD) Well Logging Engineering, the logging methods measured with CCSD, the quality control of original logging information, the logging plan of CCSD, the logging engineering management of CCSD,the logging interpretation and the results and reports made with CCSD.

  3. Chemical logging of geothermal wells

    Science.gov (United States)

    Allen, C.A.; McAtee, R.E.

    The presence of geothermal aquifers can be detected while drilling in geothermal formations by maintaining a chemical log of the ratio of the concentrations of calcium to carbonate and bicarbonate ions in the return drilling fluid. A continuous increase in the ratio of the concentrations of calcium to carbonate and bicarbonate ions is indicative of the existence of a warm or hot geothermal aquifer at some increased depth.

  4. New Achievements in Well Logging Technology

    Institute of Scientific and Technical Information of China (English)

    Tan Tingdong

    1996-01-01

    @@ In the first five years of 1990s, new achievements made in China's onshore well logging technology have enhanced the benefits of exploration and development for complex oil and gas reservoirs and have thus showed the trend of the development of China's well logging technology towards the end of this century.

  5. Well Logging Equipment Updated in China

    Institute of Scientific and Technical Information of China (English)

    Xu Lili

    1996-01-01

    @@ As one of the ten principal disciplines in the petroleum industry, well logging has been developed for about 55years in China and is playing an increasingly important role in the country's oil and gas exploration and development.

  6. Computer analysis of digital well logs

    Science.gov (United States)

    Scott, James H.

    1984-01-01

    A comprehensive system of computer programs has been developed by the U.S. Geological Survey for analyzing digital well logs. The programs are operational on a minicomputer in a research well-logging truck, making it possible to analyze and replot the logs while at the field site. The minicomputer also serves as a controller of digitizers, counters, and recorders during acquisition of well logs. The analytical programs are coordinated with the data acquisition programs in a flexible system that allows the operator to make changes quickly and easily in program variables such as calibration coefficients, measurement units, and plotting scales. The programs are designed to analyze the following well-logging measurements: natural gamma-ray, neutron-neutron, dual-detector density with caliper, magnetic susceptibility, single-point resistance, self potential, resistivity (normal and Wenner configurations), induced polarization, temperature, sonic delta-t, and sonic amplitude. The computer programs are designed to make basic corrections for depth displacements, tool response characteristics, hole diameter, and borehole fluid effects (when applicable). Corrected well-log measurements are output to magnetic tape or plotter with measurement units transformed to petrophysical and chemical units of interest, such as grade of uranium mineralization in percent eU3O8, neutron porosity index in percent, and sonic velocity in kilometers per second.

  7. Well logging utilizing superposition of step-profile responses of logging tools to improve logs

    Energy Technology Data Exchange (ETDEWEB)

    Edmundson, H. N.

    1984-11-20

    Disclosed is a method of improving well logs, such as induction logs and laterologs, by taking into account the effect on a logs and laterologs, by taking into account the effect on a log measurement both of the particular bed in which it is taken and of one or more other beds. In one example the process starts with an original induction log and a provisional layered formation which is based thereon and is characterized by bed boundaries and constant induction log levels within a bed. A provisional reconstructed log is built up by applying the tool response to the layered formation by a new technique which makes this expedient enough to be practicable. The reconstructed log is matched against the original log, and the layered formation is refined accordingly, by adding and/or shifting boundaries and/or by changing the measurement levels within beds, until the match is satisfactory. The original log is then converted to an improved an improved log on the basis of the latest layered formation. Modifications include use of laterologs and to improve induction logs.

  8. Well logging: utilizing superposition of step-profile responses of logging tools to improve logs

    Energy Technology Data Exchange (ETDEWEB)

    Lacour-Gayet, Ph. J.

    1984-12-04

    Disclosed is a method of improving well logs, such as induction logs and LATEROLOGS, by taking into account the effect on a log measurement both of the particular bed in which it is taken and of one or more other beds. In one example the process starts with an original induction log and a provisional layered formation which is based thereon and is characterized by bed boundaries and constant induction log levels within a bed. A provisional reconstructed log is built up by applying the tool response to the layered formation by a new technique which makes this expedient enough to be practicable. The reconstructed log is matched against the original log, and the layered formation is refined accordingly, by adding and/or shifting boundaries and/or by changing the measurement levels within beds, until the match is satisfactory. The original log is then converted to an improved log on the basis of the latest layered formation. Modifications include use of LATEROLOG measurements to improve LATEROLOGS and to improve induction logs.

  9. Well logging utilizing superposition of step-profile responses of logging tools to improve logs

    Energy Technology Data Exchange (ETDEWEB)

    Minne, J.-C.

    1984-11-13

    Disclosed is a method of improving well logs, such as induction logs and LATERLOGS, by taking into account the effect on a log measurement both of the particular bed in which it is taken and of one or more other beds. In one example the process starts with an original induction log and a provisional layered formation which is based thereon and is characterized by bed boundaries and constant induction log levels within a bed. A provisional reconstructed log is built up by applying the tool response to the layered formation by a new technique which makes this expedient enough to be practicable. The reconstructed log is matched against the original log, and the layered formation is refined accordingly, by adding and/or shifting boundaries and/or by changing the measurement levels within beds, until the match is satisfactory. The original log is then converted to an improved log on the basis of the latest layered formation. Modifications include use of LATEROLOG measurements to improve LATEROLOGS and to improve induction logs.

  10. Unconventional neutron sources for oil well logging

    Energy Technology Data Exchange (ETDEWEB)

    Frankle, C.M., E-mail: cfrankle@lanl.gov; Dale, G.E.

    2013-09-21

    Americium–Beryllium (AmBe) radiological neutron sources have been widely used in the petroleum industry for well logging purposes. There is strong desire on the part of various governmental and regulatory bodies to find alternate sources due to the high activity and small size of AmBe sources. Other neutron sources are available, both radiological ({sup 252}Cf) and electronic accelerator driven (D–D and D–T). All of these, however, have substantially different neutron energy spectra from AmBe and thus cause significantly different responses in well logging tools. We report on simulations performed using unconventional sources and techniques to attempt to better replicate the porosity and carbon/oxygen ratio responses a well logging tool would see from AmBe neutrons. The AmBe response of these two types of tools is compared to the response from {sup 252}Cf, D–D, D–T, filtered D–T, and T–T sources. -- Highlights: • AmBe sources are widely used for well logging purposes. • Governmental bodies would prefer to minimize AmBe use. • Other neutron sources are available, both radiological and electronic. • Tritium–tritium spectrum neutrons have similar logging tool response to AmBe. • A tritium–tritium neutron generator may be a viable AmBe replacement.

  11. Well log characterization of natural gas hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2011-01-01

    In the last 25 years we have seen significant advancements in the use of downhole well logging tools to acquire detailed information on the occurrence of gas hydrate in nature: From an early start of using wireline electrical resistivity and acoustic logs to identify gas hydrate occurrences in wells drilled in Arctic permafrost environments to today where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gas hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. The most established and well known use of downhole log data in gas hydrate research is the use of electrical resistivity and acoustic velocity data (both compressional- and shear-wave data) to make estimates of gas hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. New downhole logging tools designed to make directionally oriented acoustic and propagation resistivity log measurements have provided the data needed to analyze the acoustic and electrical anisotropic properties of both highly inter-bedded and fracture dominated gas hydrate reservoirs. Advancements in nuclear-magnetic-resonance (NMR) logging and wireline formation testing have also allowed for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids (i.e., free-water along with clay and capillary bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms controlling the formation and occurrence of gas hydrate in nature along with data on gas hydrate reservoir properties (i.e., permeabilities) needed to accurately predict gas production rates for various gas hydrate

  12. Fractal Correction of Well Logging Curves

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It is always significant for assessing and evaluation of oil-bearing layers, especially for well logging data processing and interpretation of non-marine oil beds to get more accurate physical properties in thin and inter-thin layers. This paper presents a definition of measures and the measure presents power law relation with the corresponded scale described by fractal theory. Thus, logging curves can be reconstructed according to this power law relation. This method uses the local structure nearby concurrent points to com pensate the average effect of logging probes and measurement errors. As an example, deep and medium induced conductivity (IMPH and IDPH) curves in ODP Leg 127 Hole 797C are reconstructed or corrected. Corrected curves are with less adjacent effects through comparison of corrected curves with original one. And also, the power spectra of corrected well logging curve are abounding with more resolution components than the original one. Thus, fractal correction method makes the well logging more resoluble for thin beds.``

  13. Geothermal well log interpretation midterm report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1979-02-01

    Reservoir types are defined according to fluid phase and temperature, lithology, geologic province, pore geometry, and salinity and fluid chemistry. Improvements are needed in lithology and porosity definition, fracture detection, and thermal evaluation for more accurate interpretation. Further efforts are directed toward improving diagnostic techniques for relating rock characteristics and log response, developing petrophysical models for geothermal systems, and developing thermal evaluation techniques. The Geothermal Well Log Interpretation study and report has concentrated only on hydrothermal geothermal reservoirs. Other geothermal reservoirs (hot dry rock, geopressured, etc.) are not considered.

  14. Selecting Aquifer Wells for Planned Gyroscopic Logging

    Energy Technology Data Exchange (ETDEWEB)

    Rohe, Michael James; Studley, Gregory Wayne

    2002-04-01

    Understanding the configuration of the eastern Snake River Plain aquifer's water table is made difficult, in part, due to borehole deviation in aquifer wells. A borehole has deviation if it is not vertical or straight. Deviation impairs the analysis of water table elevation measurements because it results in measurements that are greater than the true distance from the top of the well to the water table. Conceptual models of the water table configuration are important to environmental management decision-making at the INEEL; these models are based on measurements of depth to the water table taken from aquifer wells at or near the INEEL. When accurate data on the amount of deviation in any given borehole is acquired, then measurements of depth-to-water can be adjusted to reflect the true depth so more accurate conceptual models can be developed. Collection of additional borehole deviation data with gyroscopic logging is planned for selected wells to further our confidence in the quality of water level measurements. Selection of wells for the planned logging is based on qualitative and quantitative screening criteria. An existing data set from magnetic deviation logs was useful in establishing these criteria however, are considered less accurate than gyroscopic deviation logs under certain conditions. Population distributions for 128 aquifer wells with magnetic deviation data were used to establish three quantitative screening thresholds. Qualitative criteria consisted of administrative controls, accessibility issues, and drilling methods. Qualitative criteria eliminated all but 116 of the 337 aquifer wells, in the vicinity of the INEEL, that were initially examined in this screening effort. Of these, 72 have associated magnetic deviation data; 44 do not. Twenty-five (25) of the 72 wells with magnetic deviation data have deviation greater than one of the three quantitative screening thresholds. These 25 are recommended for the planned gyroscopic borehole deviation

  15. Interpretation of horizontal well production logs: influence of logging tool

    Energy Technology Data Exchange (ETDEWEB)

    Ozkan, E. [Colorado School of Mines, Boulder, CO (United States); Sarica, C. [Pennsylvania State Univ., College Park, PA (United States); Haci, M. [Drilling Measurements, Inc (United States)

    1998-12-31

    The influence of a production-logging tool on wellbore flow rate and pressure measurements was investigated, focusing on the disturbence caused by the production-logging tool and the coiled tubing on the original flow conditions in the wellbore. The investigation was carried out using an analytical model and single-phase liquid flow was assumed. Results showed that the production-logging tool influenced the measurements as shown by the deviation of the original flow-rate, pressure profiles and low-conductivity wellbores. High production rates increase the effect of the production-logging tool. Recovering or inferring the original flow conditions in the wellbore from the production-logging data is a very complex process which cannot be solved easily. For this reason, the conditions under which the information obtained by production-logging is meaningful is of considerable practical interest. 7 refs., 2 tabs., 15 figs.

  16. A Brief Introduction of Jianghan Well Logging Institute

    Institute of Scientific and Technical Information of China (English)

    Hu Yiliang

    1996-01-01

    @@ Jianghan Well Logging Institute(JHWLI), situated in Qianjiang city of Hubei Province and founded in 1979, is the only specialized well logging institute affiliated to China National Petroleum Corporation (CNPC), It has a basic logging method research department, an image logging research department, a technological support department., a new-tech development & promotion department, a well logging service department and a diversification company. They are engaged in the researchs and development of well logging technology and its application in addition to in site well logging services.

  17. Application of well log normalization in coalfield seismic inversion

    Institute of Scientific and Technical Information of China (English)

    Qing-Xi LIN; Su-Zhen SHI; Shan-Shan LI; Li LUO; Juan LI; Zi-Liang YU

    2013-01-01

    During the process of coal prospecting and exploration,different measurement time,different logging instruments and series can lead to systematic errors in well logs.Accordingly,all logging curves need to be normalized in the mining area.By studying well-logging normalization methods,and focusing on the characteristics of the coalfield,the frequency histogram method was used in accordance with the condition of the Guqiao Coal Mine.In this way,the density and sonic velocity at marker bed in the non-key well were made to close to those in the key well,and were eventually equal.Well log normalization was completed when this method was applied to the entire logging curves.The results show that the scales of logging data were unified by normalizing coal logging curves,and the logging data were consistent with wave impedance inversion data.A satisfactory inversion effect was obtained.

  18. 10 CFR 39.13 - Specific licenses for well logging.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Specific licenses for well logging. 39.13 Section 39.13 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Specific Licensing Requirements § 39.13 Specific licenses for well logging. The Commission will approve an application for a specific license for the...

  19. Development of a Single-Borehole Radar for Well Logging

    OpenAIRE

    Zheng-ou Zhou; Qing Zhao; Haining Yang; Tingjun Li

    2012-01-01

    An impulse-based single-borehole radar prototype has been developed for well logging. The borehole radar is comprised of subsurface sonde and surface equipment. An armored 7-conductor well logging cable is used to connect subsurface sonde and surface equipment which is well compatible with the other well logging instruments. The performance experiments of the prototype have been conducted in a test field. The results show that the prototype system is capable of detecting the target which is 8...

  20. Geothermal well log interpretation state of the art. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Sanyal, S.K.; Wells, L.E.; Bickham, R.E.

    1980-01-01

    An in-depth study of the state of the art in Geothermal Well Log Interpretation has been made encompassing case histories, technical papers, computerized literature searches, and actual processing of geothermal wells from New Mexico, Idaho, and California. A classification scheme of geothermal reservoir types was defined which distinguishes fluid phase and temperature, lithology, geologic province, pore geometry, salinity, and fluid chemistry. Major deficiencies of Geothermal Well Log Interpretation are defined and discussed with recommendations of possible solutions or research for solutions. The Geothermal Well Log Interpretation study and report has concentrated primarily on Western US reservoirs. Geopressured geothermal reservoirs are not considered.

  1. Development of a Single-Borehole Radar for Well Logging

    Directory of Open Access Journals (Sweden)

    Zheng-ou Zhou

    2012-12-01

    Full Text Available An impulse-based single-borehole radar prototype has been developed for well logging. The borehole radar is comprised of subsurface sonde and surface equipment. An armored 7-conductor well logging cable is used to connect subsurface sonde and surface equipment which is well compatible with the other well logging instruments. The performance experiments of the prototype have been conducted in a test field. The results show that the prototype system is capable of detecting the target which is 8 meters away from the borehole. This radar prototype has been employed in a real oil field well with a depth of about 1600 meters. Compared with conventional resistivity well logging tools, the prototype system provides comprehensive well-bore formation analysis information.  

  2. A time-driven transmission method for well logging networks

    Institute of Scientific and Technical Information of China (English)

    Wu Ruiqing; Chen Wei; Chen Tianqi; Li Qun

    2009-01-01

    Long delays and poor real-time transmission are disadvantageous to well logging networks consisting of multiple subnets. In this paper, we proposed a time-driven transmission method (TDTM) to improve the efficiency and precision of logging networks. Using TDTM, we obtained well logging curves by fusing the depth acquired on the surface, and the data acquired in downhole instruments based on the synchronization timestamp. For the TDTM, the precision of time synchronization and the data fusion algorithm were two main factors influencing system errors. A piecewise fractal interpolation was proposed to fast fuse data in each interval of the logging curves. Intervals with similar characteristics in curves were extracted based on the change in the histogram of the interval. The TDTM is evaluated with a sonic curve, as an example. Experimental results showed that the fused data had little error, and the TDTM was effective and suitable for the logging networks.

  3. What's new in well logging and formation evaluation

    Science.gov (United States)

    Prensky, S.

    2011-01-01

    A number of significant new developments is emerging in well logging and formation evaluation. Some of the new developments include an ultrasonic wireline imager, an electromagnetic free-point indicator, wired and fiber-optic coiled tubing systems, and extreme-temperature logging-while-drilling (LWD) tools. The continued consolidation of logging and petrophysical service providers in 2010 means that these innovations are increasingly being provided by a few large companies. Weatherford International has launched a slimhole cross-dipole tool as part of the company's line of compact logging tools. The 26-ft-long Compact Cross-Dipole Sonic (CXD) tool can be run as part of a quad-combo compact logging string. Halliburton has introduced a version of its circumferential acoustic scanning tool (CAST) that runs on monoconductor cable (CAST-M) to provide high-resolution images in open hole and in cased hole for casing and cement evaluation.

  4. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore K.

    2003-02-10

    The objective of this project was to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity.

  5. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore K.

    2003-02-10

    The objective of this project was to characterize the fluid properties and fluid-rock interactions which are needed for formation evaluation by NMR well logging. NMR well logging is finding wide use in formation evaluation. The formation parameters commonly estimated were porosity, permeability, and capillary bound water. Special cases include estimation of oil viscosity, residual oil saturation, location of oil/water contact, and interpretation on whether the hydrocarbon is oil or gas.

  6. Discrimination of Natural Fractures Using Well Logging Curve Unit

    Institute of Scientific and Technical Information of China (English)

    Liu Hongqi; Peng Shimi; Zhou Yongyi; Xue Yongchao

    2004-01-01

    It is very difficult to discriminate natural fractures using conventional well log data, especially for most of the matured oilfields in China, because the raw data were acquired with relatively obsolete tools. The raw data include only GR and SP curves, indicative of lithology, AC curves, used to calculate the porosity of the formation, and a set of logging curves from various electrode length resistivity by laterolog. On the other hand, these oilfields usually have a large amount of core data which directly display the characteristics of the formation, and enough information of injection and production. This paper describes an approach through which logging curves are calibrated in terms of the raw data, and then a prototype model of natural fractures is established based on the investigation of core data from 43 wells, totaling 4 000 m in length. A computer program has been developed according to this method. Through analysis and comparison of the features of logging curves, this paper proposes a new concept, the well logging curve unit. By strictly depicting its shape through mathematical methods, the natural facture can be discriminated. This work also suggests an equation to estimate the probability of fracture occurrence, and finally other fracture parameters are calculated using some experimental expressions. With this methodology, logging curves from 100 wells were interpreted, the results of which agree with core data and field information.

  7. Electronic neutron sources for compensated porosity well logging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, A. X.; Antolak, A. J.; Leung, K. -N.

    2012-08-01

    The viability of replacing Americium–Beryllium (Am–Be) radiological neutron sources in compensated porosity nuclear well logging tools with D–T or D–D accelerator-driven neutron sources is explored. The analysis consisted of developing a model for a typical well-logging borehole configuration and computing the helium-3 detector response to varying formation porosities using three different neutron sources (Am–Be, D–D, and D–T). The results indicate that, when normalized to the same source intensity, the use of a D–D neutron source has greater sensitivity for measuring the formation porosity than either an Am–Be or D–T source. The results of the study provide operational requirements that enable compensated porosity well logging with a compact, low power D–D neutron generator, which the current state-of-the-art indicates is technically achievable.

  8. Electronic neutron sources for compensated porosity well logging

    Energy Technology Data Exchange (ETDEWEB)

    Chen, A.X., E-mail: axchen@sandia.gov [Sandia National Laboratories, Livermore, CA 94550 (United States); Antolak, A.J.; Leung, K.-N. [Sandia National Laboratories, Livermore, CA 94550 (United States)

    2012-08-21

    The viability of replacing Americium-Beryllium (Am-Be) radiological neutron sources in compensated porosity nuclear well logging tools with D-T or D-D accelerator-driven neutron sources is explored. The analysis consisted of developing a model for a typical well-logging borehole configuration and computing the helium-3 detector response to varying formation porosities using three different neutron sources (Am-Be, D-D, and D-T). The results indicate that, when normalized to the same source intensity, the use of a D-D neutron source has greater sensitivity for measuring the formation porosity than either an Am-Be or D-T source. The results of the study provide operational requirements that enable compensated porosity well logging with a compact, low power D-D neutron generator, which the current state-of-the-art indicates is technically achievable.

  9. Well log characterization of natural gas-hydrates

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.

    2012-01-01

    In the last 25 years there have been significant advancements in the use of well-logging tools to acquire detailed information on the occurrence of gas hydrates in nature: whereas wireline electrical resistivity and acoustic logs were formerly used to identify gas-hydrate occurrences in wells drilled in Arctic permafrost environments, more advanced wireline and logging-while-drilling (LWD) tools are now routinely used to examine the petrophysical nature of gas-hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Resistivity- and acoustic-logging tools are the most widely used for estimating the gas-hydrate content (i.e., reservoir saturations) in various sediment types and geologic settings. Recent integrated sediment coring and well-log studies have confirmed that electrical-resistivity and acoustic-velocity data can yield accurate gas-hydrate saturations in sediment grain-supported (isotropic) systems such as sand reservoirs, but more advanced log-analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. New well-logging tools designed to make directionally oriented acoustic and propagation-resistivity log measurements provide the data needed to analyze the acoustic and electrical anisotropic properties of both highly interbedded and fracture-dominated gas-hydrate reservoirs. Advancements in nuclear magnetic resonance (NMR) logging and wireline formation testing (WFT) also allow for the characterization of gas hydrate at the pore scale. Integrated NMR and formation testing studies from northern Canada and Alaska have yielded valuable insight into how gas hydrates are physically distributed in sediments and the occurrence and nature of pore fluids(i.e., free water along with clay- and capillary-bound water) in gas-hydrate-bearing reservoirs. Information on the distribution of gas hydrate at the pore scale has provided invaluable insight on the mechanisms

  10. Proposed geologic model based on geophysical well logs

    Energy Technology Data Exchange (ETDEWEB)

    Diaz C, S.; Puente C, I.; de la Pena L, A.

    1981-01-01

    An investigation of the subsurface based on a qualitative interpretation of well logs was carried out at Cerro Prieto to obtain information on the distribution of the different lithofacies that make up a deltaic depositional system. The sedimentological interpretation derived from the resistivity and spontaneous potential are shown in several cross-sections of the field. In addition to the sedimentological interpretation, a map of the structural geology of the region based on well logs and available geophysical information was prepared, including the results of gravity and seismic refraction surveys. The depth to the zone of hydrothermal alteration described by Elders (1980) was found by means of temperature, electrical, and radioactive logs. Two maps showing the configuration of the top of this anomaly show a clear correlation with the gravity anomalies found in the area.

  11. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    George J. Hirasaki; Kishore K. Mohanty

    2005-09-05

    The objective of this report is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. The advances made in the understanding of NMR fluid properties are summarized in a chapter written for an AAPG book on NMR well logging. This includes live oils, viscous oils, natural gas mixtures, and the relation between relaxation time and diffusivity. Oil based drilling fluids can have an adverse effect on NMR well logging if it alters the wettability of the formation. The effect of various surfactants on wettability and surface relaxivity are evaluated for silica sand. The relation between the relaxation time and diffusivity distinguishes the response of brine, oil, and gas in a NMR well log. A new NMR pulse sequence in the presence of a field gradient and a new inversion technique enables the T{sub 2} and diffusivity distributions to be displayed as a two-dimensional map. The objectives of pore morphology and rock characterization are to identify vug connectivity by using X-ray CT scan, and to improve NMR permeability correlation. Improved estimation of permeability from NMR response is possible by using estimated tortuosity as a parameter to interpolate between two existing permeability models.

  12. Well-log based prediction of thermal conductivity

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    Rock thermal conductivity (TC) is paramount for the determination of heat flow and the calculation of temperature profiles. Due to the scarcity of drill cores compared to the availability of petrophysical well logs, methods are desired to indirectly predict TC in sedimentary basins. Most...

  13. Nuclear Well Log Properties of Natural Gas Hydrate Reservoirs

    Science.gov (United States)

    Burchwell, A.; Cook, A.

    2015-12-01

    Characterizing gas hydrate in a reservoir typically involves a full suite of geophysical well logs. The most common method involves using resistivity measurements to quantify the decrease in electrically conductive water when replaced with gas hydrate. Compressional velocity measurements are also used because the gas hydrate significantly strengthens the moduli of the sediment. At many gas hydrate sites, nuclear well logs, which include the photoelectric effect, formation sigma, carbon/oxygen ratio and neutron porosity, are also collected but often not used. In fact, the nuclear response of a gas hydrate reservoir is not known. In this research we will focus on the nuclear log response in gas hydrate reservoirs at the Mallik Field at the Mackenzie Delta, Northwest Territories, Canada, and the Gas Hydrate Joint Industry Project Leg 2 sites in the northern Gulf of Mexico. Nuclear logs may add increased robustness to the investigation into the properties of gas hydrates and some types of logs may offer an opportunity to distinguish between gas hydrate and permafrost. For example, a true formation sigma log measures the thermal neutron capture cross section of a formation and pore constituents; it is especially sensitive to hydrogen and chlorine in the pore space. Chlorine has a high absorption potential, and is used to determine the amount of saline water within pore spaces. Gas hydrate offers a difference in elemental composition compared to water-saturated intervals. Thus, in permafrost areas, the carbon/oxygen ratio may vary between gas hydrate and permafrost, due to the increase of carbon in gas hydrate accumulations. At the Mallik site, we observe a hydrate-bearing sand (1085-1107 m) above a water-bearing sand (1107-1140 m), which was confirmed through core samples and mud gas analysis. We observe a decrease in the photoelectric absorption of ~0.5 barnes/e-, as well as an increase in the formation sigma readings of ~5 capture units in the water-bearing sand as

  14. Automated Variance Reduction Applied to Nuclear Well-Logging Problems

    Energy Technology Data Exchange (ETDEWEB)

    Wagner, John C [ORNL; Peplow, Douglas E. [ORNL; Evans, Thomas M [ORNL

    2009-01-01

    The Monte Carlo method enables detailed, explicit geometric, energy and angular representations, and hence is considered to be the most accurate method available for solving complex radiation transport problems. Because of its associated accuracy, the Monte Carlo method is widely used in the petroleum exploration industry to design, benchmark, and simulate nuclear well-logging tools. Nuclear well-logging tools, which contain neutron and/or gamma sources and two or more detectors, are placed in boreholes that contain water (and possibly other fluids) and that are typically surrounded by a formation (e.g., limestone, sandstone, calcites, or a combination). The response of the detectors to radiation returning from the surrounding formation is used to infer information about the material porosity, density, composition, and associated characteristics. Accurate computer simulation is a key aspect of this exploratory technique. However, because this technique involves calculating highly precise responses (at two or more detectors) based on radiation that has interacted with the surrounding formation, the transport simulations are computationally intensive, requiring significant use of variance reduction techniques, parallel computing, or both. Because of the challenging nature of these problems, nuclear well-logging problems have frequently been used to evaluate the effectiveness of variance reduction techniques (e.g., Refs. 1-4). The primary focus of these works has been on improving the computational efficiency associated with calculating the response at the most challenging detector location, which is typically the detector furthest from the source. Although the objective of nuclear well-logging simulations is to calculate the response at multiple detector locations, until recently none of the numerous variance reduction methods/techniques has been well-suited to simultaneous optimization of multiple detector (tally) regions. Therefore, a separate calculation is

  15. Advanced petrophysical interpretation of nuclear well logging data

    Energy Technology Data Exchange (ETDEWEB)

    Kozhevnikov, D.A.; Lazutkina, N.Ye. [State Oil and Gas Academy, Moscow (Russian Federation)

    1995-04-01

    A new approach to rock component using ``adaptive petrophysical tuning`` provides three crucially new benefits: an original method for interpreting well logs; an algorithm for adaptive tuning and a reliable method of isolating reservoirs within a section. The latter can be regarded as a kind of ``petrophysical filtration`` based on using the dynamic porosity. Some results of component analyses of terrigenous deposits of the Tyumen suite (West Siberia) are presented. (author).

  16. Advanced petrophysical interpretation of nuclear well logging data

    Science.gov (United States)

    Kozhevnikov, D. A.; Lazutkina, N. Ye.

    1995-04-01

    A new approach to rock component analyses using “adaptive petrophysical tuning” provides three crucially new benefits: an original method for interpreting well logs; an algorithm for adaptive tuning and a reliable method of isolating reservoirs within a section. The latter can be regarded as a kind of “petrophysical filtration” based on using the dynamic porosity. Some results of component analyses of terrigenous deposits of the Tyumen suite (West Siberia) are presented.

  17. Irrigation Wells from the Nevada Division of Water Resources Well Log Database

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This data set was derived from the Nevada Department of Conservation and Natural Resources, Division of Water Resources (NDWR) well log data base...

  18. Image Reconstruction for Invasive ERT in Vertical Oil Well Logging

    Institute of Scientific and Technical Information of China (English)

    周海力; 徐立军; 曹章; 胡金海; 刘兴斌

    2012-01-01

    An invasive electrical resistance tomographic sensor was proposed for production logging in vertical oil well.The sensor consists of 24 electrodes that are fixed to the logging tool,which can move in the pipeline to acquire data on the conductivity distribution of oil/water mixture flow at different depths.A sensitivity-based algorithm was introduced to reconstruct the cross-sectional images.Analysis on the sensitivity of the sensor to the distribution of oil/water mixture flow was carried out to optimize the position of the imaging cross-section.The imaging results obtained using various boundary conditions at the pipe wall and the logging tool were compared.Eight typical models with various conductivity distributions were created and the measurement data were obtained by solving the forward problem of the sensor system.Image reconstruction was then implemented by using the simulation data for each model.Comparisons between the models and the reconstructed images show that the number and spatial distribution of the oil bubbles can be clearly identified.

  19. Lithology and hydrothermal alteration determination from well logs for the Cerro Prieto Wells, Mexico

    Science.gov (United States)

    Ershaghi, I.; Ghaemian, S.; Abdassah, D.

    1981-10-01

    The characteristics of geophysical well logs are compared against the sand-shale series of the sedimentary column of the Cerro Prieto Geothermal Field, Mexico. It is shown that the changes in mineralogy of the rocks because of hydrothermal alteration are not easily detectable on the existing logs. However, if the behavior of clay minerals alone is monitored, the onset of the hydrothermally altered zones may be estimated from the well logs. The effective concentration of clay-exchange cations, Q/sub v/, is computed using the data available from conventional well logs. Zones indicating the disappearance of low temperature clays are considered hydrothermally altered formations with moderate to high permeability and temperature, and suitable for completion purposes.

  20. Monte Carlo Simulations of Neutron Oil well Logging Tools

    CERN Document Server

    Azcurra, M

    2002-01-01

    Monte Carlo simulations of simple neutron oil well logging tools into typical geological formations are presented.The simulated tools consist of both 14 MeV pulsed and continuous Am-Be neutron sources with time gated and continuous gamma ray detectors respectively.The geological formation consists of pure limestone with 15% absolute porosity in a wide range of oil saturation.The particle transport was performed with the Monte Carlo N-Particle Transport Code System, MCNP-4B.Several gamma ray spectra were obtained at the detector position that allow to perform composition analysis of the formation.In particular, the ratio C/O was analyzed as an indicator of oil saturation.Further calculations are proposed to simulate actual detector responses in order to contribute to understand the relation between the detector response with the formation composition

  1. Prediction of thermal conductivity of sedimentary rocks from well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    2014-01-01

    . A common procedure in the latter approach is the use of empirical relations between TC and different petrophysical properties. Although numerous prediction equations were developed in the past five decades, none of these seem to be universally applicable for all major types of sedimentary rocks (clastics...... combinations of standard geophysical well-logs. In combination with a feasible mixing-model (i.e. geometric mean model) bulk TC is computed along borehole profiles. The underlying approach was proposed by Fuchs & Förster (2014) and rests upon the detailed analysis of the interrelations between major physical...... parameters (i.e. thermal conductivity, density, hydrogen index, sonic interval transit time, gamma-ray response, photoelectric factor) of artificial mineral assemblages consisting 15 rock-forming minerals that are used in different combinations to typify sedimentary rocks. The predictive capacity of the new...

  2. Feasibility investigation and design study of optical well logging methods for high temperature geothermal wells

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, R.K.; Anderson, R.E.; Ash, J.I.; Beissner, R.E.; Smith, V.D.

    1978-03-01

    The objective of this project was exploration of a novel approach to high temperature well logging, based on a system of optical transducers and an optical transmission line both theoretically capable of operation to at least 600/sup 0/C. The scope of the work involved the accomplishment of ten specific tasks. These had as their objective the determination of feasibility, and identification of major problem areas, in the implementation of continuous temperature logging of geothermal wells using optical techniques. The following tasks are reported: literature review and data compilation, measurement of fiber properties production fiber procurement, investigation of methods of fiber termination, cable design and fabrication, and sensor and system studies. (MHR)

  3. Log-concavity property for some well-known distributions

    Directory of Open Access Journals (Sweden)

    G. R. Mohtashami Borzadaran

    2011-12-01

    Full Text Available Interesting properties and propositions, in many branches of science such as economics have been obtained according to the property of cumulative distribution function of a random variable as a concave function. Caplin and Nalebuff (1988,1989, Bagnoli and Khanna (1989 and Bagnoli and Bergstrom (1989 , 1989, 2005 have discussed the log-concavity property of probability distributions and their applications, especially in economics. Log-concavity concerns twice differentiable real-valued function g whose domain is an interval on extended real line. g as a function is said to be log-concave on the interval (a,b if the function ln(g is a concave function on (a,b. Log-concavity of g on (a,b is equivalent to g'/g being monotone decreasing on (a,b or (ln(g" 6] have obtained log-concavity for distributions such as normal, logistic, extreme-value, exponential, Laplace, Weibull, power function, uniform, gamma, beta, Pareto, log-normal, Student's t, Cauchy and F distributions. We have discussed and introduced the continuous versions of the Pearson family, also found the log-concavity for this family in general cases, and then obtained the log-concavity property for each distribution that is a member of Pearson family. For the Burr family these cases have been calculated, even for each distribution that belongs to Burr family. Also, log-concavity results for distributions such as generalized gamma distributions, Feller-Pareto distributions, generalized Inverse Gaussian distributions and generalized Log-normal distributions have been obtained.

  4. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore, K.

    2001-07-13

    The objective of this project is to characterize the fluid properties and fluid-rock interactions that are needed for formation evaluation by NMR well logging. This is the first annual progress report submitted to the DOE. It reports on the work completed during the reporting period even if it may have started before this period. This project is a partnership between Professor George J. Hirasaki at Rice University and Professor Kishore Mohanty at University of Houston. In addition to the DOE, this project is supported by a consortium of oil companies and service companies. The fluid properties characterization has emphasized the departure of live oils from correlations based on dead oils. Also, asphaltic components can result in a difference between the T1 and T2 relaxation time distributions as well as reduce the hydrogen index. The fluid rock characterizations that are reported here are the effects of wettability and internal magnetic field gradients. A pore reconstruction method ha s been developed to recreate three-dimensional porous media from two-dimensional images that reproduce some of their key statistical properties. A Monte Carlo simulation technique has been developed to calculate the magnetization decay in fluid saturated porous media given their pore structure.

  5. Symposium on high-temperature well-logging instrumentation

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, B.R. (comp.)

    1986-06-01

    The symposium contains papers about developments in borehole logging instrumentation that can withstand downhole temperatures in excess of 300/sup 0/C and pressures greater than 103 MPa. Separate abstracts have been prepared for individual papers. (ACR)

  6. Interpretations from resistivity and lithologic logs in selected wells in the Williston basin

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data represent the interpretations from borehole electric (resistivity) logs from oil and gas wells and lithologic logs from nearby water wells. These...

  7. Sedimentary facies interpretation of Gamma Ray (GR log as basic well logs in Central and Lower Indus Basin of Pakistan

    Directory of Open Access Journals (Sweden)

    Adeel Nazeer

    2016-11-01

    Full Text Available Rocks and most type of soils emit Gamma Ray (GR in varying amount. The emitting elements of primary gamma radiations include potassium 40, uranium, and thorium which are associated with rocks forming minerals in variable amount. GR log is used to predict the varying lithology in borehole by measuring the spontaneous emission of GR radiation from rocks. Role of GR logs in the identification of subsurface facies is the main focused research theme of this manuscript including with objective of brief introduction of GR log and its applications in the identification of facies in the field of Petroleum Geosciences by analyzing the examples of GR log(s from wells, Lower Indus Basin, Pakistan.

  8. Progress in NMR Applications to Well Logging and Formation Evaluation

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ Since its discovery in 1946, NMR has become a valuable tool in physics, chemistry, biology, and medicine. With the invention of NMR logging tools that take the medical MRI or laboratory NMR equipment and turn it inside-out, the application of sophisticated laboratory techniques to determine formation properties in situ is now available. The capability has opened a new era in formation evaluation just as the introduction of NMR has revolutionized the other scientific areas.

  9. Comprehensive study of LASL Well C/T-2 Roosevelt Hot Springs KGRA, Utah, and applications to geothermal well logging

    Energy Technology Data Exchange (ETDEWEB)

    Glenn, W.E.; Hulen, J.B.; Nielson, D.L.

    1981-02-01

    Utah State Geothermal Well 9-1 in the Roosevelt Hot Springs KGRA, Beaver County, Utah, has been donated by Phillips Petroleum Company for calibration and testing of well-logging equipment in the hot, corrosive, geothermal environment. It is the second Calibration/Test Well (C/T-2) in the Geothermal Log Interpretation Program. A study of cuttings and well logs from Well C/T-2 was completed. This synthesis and data presentation contains most of the subsurface geologic information needed to effect the total evaluation of geophysical logs acquired in this geothermal calibration/test well, C/T-2.

  10. Thermal Conductivity from Core and Well log Data

    CERN Document Server

    Hartmann, Andreas; Clauser, Christoph

    2008-01-01

    The relationships between thermal conductivity and other petrophysical properties have been analysed for a borehole drilled in a Tertiary Flysch sequence. We establish equations that permit us to predict rock thermal conductivity from logging data. A regression analysis of thermal conductivity, bulk density, and sonic velocity yields thermal conductivity with an average accuracy of better than 0.2 W/(m K). As a second step, logging data is used to compute a lithological depth profile, which in turn is used to calculate a thermal conductivity profile. From a comparison of the conductivity-depth profile and the laboratory data it can be concluded that thermal conductivity can be computed with an accuracy of less than 0.3 W/(m K)from conventional wireline data. The comparison of two different models shows that this approach can be practical even if old and incomplete logging data is used. The results can be used to infer thermal conductivity for boreholes without appropriate core data that are drilled in a simil...

  11. GEOLOGICAL APPLICATIONS OF WELL LOGS: AN INTRODUCTORY BIBLIOGRAPHY AND SURVEY OF THE WELL LOGGING LITERATURE THROUGH SEPTEMBER 1986 ARRANGED BY SUBJECT.

    Science.gov (United States)

    Prensky, Stephen E.

    1987-01-01

    This report includes over 1,350 individual citations as well as a first-author index. The purpose of this bibliography is twofold, 1) to provide a basic, first-stop resource on well logging which the non-specialist, i. e. , geoscientist, can consult and, 2) to provide a reference on geologic applications for the non-geoscientist, i. e. , log analyst or petroleum engineer, as well as for the geoscientist.

  12. Attempt to approach geological interpretation using integrate well-logging curve analysis method

    Energy Technology Data Exchange (ETDEWEB)

    Yalin, F.

    1988-01-01

    In recent years, people widely use various well-logging curves to determine geological horizon, lithology, hydrocarbon content, etc. and have reaped some effects. The integrate well-logging curve analysis method described here adopts five types of well-logging curves: microlog curve, resistivity-logging curve, induced-current-log curve, spontaneous-potential curve and sonic-logging curve, which are used to form ''ladder diagram'' and ''spider diagram'' for the analysis. Logging curves taken from some wells in west Baxian depression are used to discuss how they analyse lithology and hydrocarbon content of formation. This method favors the comprehensive interpretation of anticline and lithology.

  13. Automated interpretation of nuclear and electrical well loggings for basalt characterization (case study from southern Syria).

    Science.gov (United States)

    Asfahani, J; Abdul Ghani, B

    2012-10-01

    Nuclear well logging, including natural gamma ray, density and neutron-porosity techniques are used with electrical well logging of long and short normal techniques in order to characterize the large extended basaltic areas in southern Syria. Four kinds of basalt have been identified: hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay, based on a statistical analysis approach with the threshold concept. The statistical conditions for such basalt characterization have been programmed in the present research to automatically interpret the well logging data for establishing and predicting the lithological cross-section of the studied well. A specific computer program has been written in Delphi for such purposes. The program is flexible and it can be used for other well logging applications by changing the statistical conditions and the well logging parameters. The program has been successfully tested on the Kodanah well logging data in southern Syria.

  14. Neutron and density logging responses to gas reservoir for well-balanced and under-balanced logging:Gas reservoirs of sandstone in a western China field

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Studying the response differences between neutron and density logging of gas reservoir for well-balanced and under-balanced logging will be of significance in evaluation of gas reservoir under the under-balanced condition and application of logging data. With Monte Carlo simulation technique,the paper obtains the relationship between neutron and density logging measurement and borehole di-ameter,porosity or gas saturation for well-balanced and under-balanced logging. The conclusions show that the response trend of under-balanced logging to gas reservoirs agrees with that of well-balanced logging with small borehole,and under-balanced logging data can be used usually as well-balanced logging data. When borehole diameter is large,under-balanced logging data should be corrected for the influences of borehole.

  15. Application of oil-field well log interpretation techniques to the Cerro Prieto Geothermal Field

    Energy Technology Data Exchange (ETDEWEB)

    Ershaghi, I.; Phillips, L.B.; Dougherty, E.L.; Handy, L.L.

    1979-10-01

    An example is presented of the application of oil-field techniques to the Cerro Prieto Field, Mexico. The lithology in this field (sand-shale lithology) is relatively similar to oil-field systems. The study was undertaken as a part of the first series of case studies supported by the Geothermal Log Interpretation Program (GLIP) of the US Department of Energy. The suites of logs for individual wells were far from complete. This was partly because of adverse borehole conditions but mostly because of unavailability of high-temperature tools. The most complete set of logs was a combination of Dual Induction Laterolog, Compensated Formation Density Gamma Ray, Compensated Neutron Log, and Saraband. Temperature data about the wells were sketchy, and the logs had been run under pre-cooled mud condition. A system of interpretation consisting of a combination of graphic and numerical studies was used to study the logs. From graphical studies, evidence of hydrothermal alteration may be established from the trend analysis of SP (self potential) and ILD (deep induction log). Furthermore, the cross plot techniques using data from density and neutron logs may help in establishing compaction as well as rock density profile with depth. In the numerical method, R/sub wa/ values from three different resistivity logs were computed and brought into agreement. From this approach, values of formation temperature and mud filtrate resistivity effective at the time of logging were established.

  16. Well Inventory and Geophysical Logging of Selected Wells in Troup County, Georgia, 2007-2008

    Science.gov (United States)

    Peck, Michael F.; Leeth, David C.; Hamrick, Michael D.

    2008-01-01

    The U.S. Geological Survey (USGS) - in cooperation with the Troup County Board of Commissioners - conducted a well inventory to provide information to help evaluate ground-water resources for Troup County, Georgia. In addition, borehole geophysical logs were collected in selected wells to provide a better understanding of the subsurface geologic and water-bearing characteristics in specific areas of interest. This investigation provides information to help guide future ground-water development and water-management decisions for Troup County while enhancing understanding of the hydrogeology of fractured rocks in the Piedmont physiographic province. This report presents well data compiled from USGS files and from site visits to wells during November and December 2007. Data were entered into the USGS National Water Information System (NWIS) and made available on the Web at http://waterdata.usgs.gov/ga/nwis/inventory. Previous studies of ground-water resources have been conducted in the vicinity, but did not include Troup County. The ground-water resources of Heard and Coweta Counties, located north and northeast, respectively, of Troup County were part of a larger study by Cressler and others (1983) that encompassed the Greater Atlanta Region. That study evaluated the quantity and quality of ground water in the Atlanta region and described the methods that could be used for locating high-yielding wells in the Piedmont Province. The geology underlying the Atlanta area is similar to that underlying Troup County. Clarke and Peck (1990) conducted a similar investigation that included Meriwether and Coweta Counties, located to the east and northeast of Troup County.

  17. Flow imaging method of electromagnetic measurement in well logging

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Multiphase flow in an oil well is a dynamic phenomenon of inhomogeneous medium,which should be studied in a nonlinear way. This paper presents an electromagnetic measurement method based on the electrical property differences between oil,gas and water to scan,inverse and show the distribution and condition of multiphase flow. Both numerical simulation and physical experiments have proved that clear images could be obtained by this way.

  18. Fluid-Rock Characterization and Interactions in NMR Well Logging

    Energy Technology Data Exchange (ETDEWEB)

    Hirasaki, George J.; Mohanty, Kishore K.

    2001-07-13

    This semi-annual report briefly summarizes the progress since the 1st Annual Report issued September, 2000 and the next annual report. More detailed results will be in the annual reports. The main emphasis on fluid properties was on measurements of the relaxation time and self-diffusion coefficient of ethane and propane. Ethane is similar to methane while propane is more similar to the higher alkanes. The ratio of T1 and T2 is demonstrated to be a function of both viscosity and the NMR frequency. The diffusion-induced T2 in a uniform magnetic gradient was simulated in one dimension to seek improved understanding NMR diffusion in restricted geometry. Analytical solutions can be found for this system if the correct region of validity is used. Estimation of permeability of vuggy carbonates has been problematic because the pore body size does not correlate well with pore throat size. CT scans and CPMG NMR measurements were made on a set of vuggy carbonate rocks.

  19. Modeling and interpretation of Q logs in carbonate rock using a double porosity model and well logs

    Science.gov (United States)

    Parra, Jorge O.; Hackert, Chris L.

    2006-03-01

    Attenuation data extracted from full waveform sonic logs is sensitive to vuggy and matrix porosities in a carbonate aquifer. This is consistent with the synthetic attenuation (1 / Q) as a function of depth at the borehole-sonic source-peak frequency of 10 kHz. We use velocity and densities versus porosity relationships based on core and well log data to determine the matrix, secondary, and effective bulk moduli. The attenuation model requires the bulk modulus of the primary and secondary porosities. We use a double porosity model that allows us to investigate attenuation at the mesoscopic scale. Thus, the secondary and primary porosities in the aquifer should respond with different changes in fluid pressure. The results show a high permeability region with a Q that varies from 25 to 50 and correlates with the stiffer part of the carbonate formation. This pore structure permits water to flow between the interconnected vugs and the matrix. In this region the double porosity model predicts a decrease in the attenuation at lower frequencies that is associated with fluid flowing from the more compliant high-pressure regions (interconnected vug space) to the relatively stiff, low-pressure regions (matrix). The chalky limestone with a low Q of 17 is formed by a muddy porous matrix with soft pores. This low permeability region correlates with the low matrix bulk modulus. A low Q of 18 characterizes the soft sandy carbonate rock above the vuggy carbonate. This paper demonstrates the use of attenuation logs for discriminating between lithology and provides information on the pore structure when integrated with cores and other well logs. In addition, the paper demonstrates the practical application of a new double porosity model to interpret the attenuation at sonic frequencies by achieving a good match between measured and modeled attenuation.

  20. Log ASCII Standard (LAS) Files for Geophysical (Gamma Ray) Wireline Well Logs and Their Application to Geologic Cross Section C-C' Through the Central Appalachian Basin

    Science.gov (United States)

    Trippi, Michael H.; Crangle, Robert D.

    2009-01-01

    U.S. Geological Survey (USGS) regional geologic cross section C-C' (Ryder and others, 2008) displays key stratigraphic intervals in the central Appalachian basin. For this cross section, strata were correlated by using descriptions of well cuttings and gamma ray well log traces. This report summarizes the procedures used to convert gamma ray curves on paper well logs to the digital Log ASCII (American Standard Code for Information Interchange) Standard (LAS) format using the third-party software application Neuralog. The procedures could be used with other geophysical wireline logs also. The creation of digital LAS files from paper well logs by using Neuralog is very helpful, especially when dealing with older logs with limited or nonexistent digital data. The LAS files from the gamma ray logs of 11 wells used to construct cross section C-C' are included in this report. They may be downloaded from the index page as a single ZIP file.

  1. Did you smooth your well logs the right way for seismic interpretation?

    Science.gov (United States)

    Duchesne, Mathieu J.; Gaillot, Philippe

    2011-12-01

    Correlations between physical properties and seismic reflection data are useful to determine the geological nature of seismic reflections and the lateral extent of geological strata. The difference in resolution between well logs and seismic data is a major hurdle faced by seismic interpreters when tying both data sets. In general, log data have a resolution of at least two orders of magnitude greater than seismic data. Smoothing physical property logs improves correlation at the seismic scale. Three different approaches were used and compared to smooth a density log: binomial filtering, seismic wavelet filtering and discrete wavelet transform (DWT) filtering. Regression plots between the density logs and the acoustic impedance show that the data smoothed with the DWT is the only method that preserves the original relationship between the raw density data and the acoustic impedance. Smoothed logs were then used to generate synthetic seismograms that were tied to seismic data at the borehole site. Best ties were achieved using the synthetic seismogram computed with the density log processed with the DWT. The good performance of the DWT is explained by its adaptive multi-scale characteristic which preserved significant local changes of density on the high-resolution data series that were also pictured at the seismic scale. Since synthetic seismograms are generated using smoothed logs, the choice of the smoothing method impacts on the quality of seismic-to-well ties. This ultimately can have economical implications during hydrocarbon exploration or exploitation phases.

  2. Results of investigations at the Zunil geothermal field, Guatemala: Well logging and brine geochemistry

    Energy Technology Data Exchange (ETDEWEB)

    Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. (Los Alamos National Lab., NM (USA)); Medina, V. (Instituto Nacional de Electrificacion, Guatemala City (Guatemala). Unidad de Desarollo Geotermico)

    1991-07-01

    The well logging team from Los Alamos and its counterpart from Central America were tasked to investigate the condition of four producing geothermal wells in the Zunil Geothermal Field. The information obtained would be used to help evaluate the Zunil geothermal reservoir in terms of possible additional drilling and future power plant design. The field activities focused on downhole measurements in four production wells (ZCQ-3, ZCQ-4, ZCQ-5, and ZCQ-6). The teams took measurements of the wells in both static (shut-in) and flowing conditions, using the high-temperature well logging tools developed at Los Alamos National Laboratory. Two well logging missions were conducted in the Zunil field. In October 1988 measurements were made in well ZCQ-3, ZCQ-5, and ZCQ-6. In December 1989 the second field operation logged ZCQ-4 and repeated logs in ZCQ-3. Both field operations included not only well logging but the collecting of numerous fluid samples from both thermal and nonthermal waters. 18 refs., 22 figs., 7 tabs.

  3. Open sesame: IDC launches Internet site to access well logs, other data

    Energy Technology Data Exchange (ETDEWEB)

    Marsters, S.

    2001-06-01

    International Datashare Corporation has recently opened a new website - www.EnerGISite.com - to make it possible for geologists and geophysicists to access its vast store of Canadian well logs. The well logs have been reproduced over the years in a variety of forms: microfiche, half-scale prints and film, and full-scale prints and film. More recently, IDC has digitized a large number of logs and captured the images in raster form (i.e. scanned, not digitized). The digital and raster logs will, henceforth, be accessible in the EnerGISite through a GIS map front end. When users log on to the site, a picture of world will appear. Clicking on the Canadian landmass, the database will the tell the user what data is available. By zooming in on a particular area of the map such as for example Alberta, all well locations will be shown. By selecting individual wells, users can find out if raster and digital curves exist. Individual logs can be purchased on a transactional basis. Companies can also subscribe for unlimited usage. Logs will be sent by e-mail, or downloaded directly into a user-created file. U.S. data is expected to be launched in July 2001, with selected areas of the world added at a later date. Production data for a site will be provided by International Petrodata Limited, a business partner of IDC. New datasets and software tools to the site are planned by IDC over time.

  4. 75 FR 75995 - Request for Comments on Helium-3 Use in the Oil and Natural Gas Well Logging Industry

    Science.gov (United States)

    2010-12-07

    ... manufacture neutron detectors used by the well logging industry or wireline or Logging-While-Drilling tools incorporating neutron detectors, and whether companies purchase or lease logging tools that contain neutron... for Comments on Helium-3 Use in the Oil and Natural Gas Well Logging Industry AGENCY: Office of...

  5. Fracture Detection: Interpretation of Well Logs to Select Packer Seats and Locate Injection Intervals

    Energy Technology Data Exchange (ETDEWEB)

    Dreesen, D.S.; Burns, K.L.; Chavez, P.; Dash, Z.V.; Kelkar, S.; Kolar, J.; Levy, S.S.

    1986-01-21

    A wireline and mud logging program has been conducted in conjunction with redrilling operations in well EE-3 at the Fenton Hill Hot Dry Rock (HDR) site near Valles Caldera, New Mexico. The trajectory for the new bore, EE-3A, penetrated a fractured zone stimulated from adjacent well EE-2 and thereby established hydraulic communication. To test and stimulate selected zones in EE-3A inflatable open hole packers designed for high temperature service were used. Proper identification and selection of packer seats was crucial to the success of the project. The logging program successfully identified five competent packer seats in six attempts. Wireline temperature, caliper, sonic televiewer and natural gamma ray logs were used in conjunction with mud logs, drill cuttings and drilling parameter data to locate fractures, out-of-gage hole, temperature anomalies and mineralized zones which were avoided in selection of the packer seats.

  6. Correlation of coal basins in north Japan by frequency analysis of well logging data

    Energy Technology Data Exchange (ETDEWEB)

    Hiroshi Oda [National Institute of Advanced Industrial Science and Technology (AIST), Ibaraki (Japan). Institute for Geo-Resources and Environment

    2005-07-01

    Some recent developments in the use of well logs to recognize the earth's orbital cycles within the Milankovitch band are described. Milankovitch orbital cycles are revealed by time series analysis of conventional well logs. Time series analysis reveals cyclic events whilst episodic events are not revealed. Cyclostratigraphy, therefore represents a method to recognize the results in the sedimentary record of orbital climate forcing sedimentary processes which may be further used as a near synchronous correlation tool across sedimentary basins. By contrast, Exxon's third order depositional sequences are not necessarily periodic and although they are considered to represent the results of rhythmicity in sea levels in the range of the half a million to upwards of 5 million years, their use could make correlation problematic and non-synchronous. The spectral analysis of the gamma ray log over the Miocene section of the MITI Sanriku-Oki borehole offshore Hachinohe City, northeast Japan reveals well defined Milankovitch cycles in the log response of the sedimentary succession. Two spectral attributes can be generated from the power spectrum (a spectral change attribute called PEFA in this work and a spectral trend attribute -INPEFA) and used to generate near synchronous basin wide correlation. These observations and further work may represent powerful tools for prospect generation activity as the curves derived better relate geophysical well logs recorded in depth to the seismic record.

  7. Data mining and well logging interpretation: application to a conglomerate reservoir

    Science.gov (United States)

    Shi, Ning; Li, Hong-Qi; Luo, Wei-Ping

    2015-06-01

    Data mining is the process of extracting implicit but potentially useful information from incomplete, noisy, and fuzzy data. Data mining offers excellent nonlinear modeling and self-organized learning, and it can play a vital role in the interpretation of well logging data of complex reservoirs. We used data mining to identify the lithologies in a complex reservoir. The reservoir lithologies served as the classification task target and were identified using feature extraction, feature selection, and modeling of data streams. We used independent component analysis to extract information from well curves. We then used the branch-and-bound algorithm to look for the optimal feature subsets and eliminate redundant information. Finally, we used the C5.0 decision-tree algorithm to set up disaggregated models of the well logging curves. The modeling and actual logging data were in good agreement, showing the usefulness of data mining methods in complex reservoirs.

  8. Performance evaluation of active wireline heave compensation systems in marine well logging environments

    Science.gov (United States)

    Liu, Tanzhuo; Iturrino, Gerardo; Goldberg, David; Meissner, Eric; Swain, Kerry; Furman, Clayton; Fitzgerald, Peter; Frisbee, Nathan; Chlimoun, Joe; Van Hyfte, John; Beyer, Ron

    2013-02-01

    The basic functionality and performance of a new Schlumberger active wireline heave compensation system on the JOIDES Resolution was evaluated during the sea trial and a 3-year period of the IODP Phase II operations. A suite of software programs was developed to enable real-time monitoring of the dynamics of logging tools, and assess the efficiency of wireline heave compensation during downhole operations. The evaluation of the system effectiveness was performed under normal logging conditions as well as during stationary tests. Logging data were analyzed for their overall quality and repeatability, and to assess the reliability of high-resolution data such as formation microscanner (FMS) electrical images. This revealed that the system reduces 65-80 % of displacement or 88-98 % variance of downhole tool motion in stationary mode under heave conditions of ±0.2-1.5 m and water depths of 300-4,500 m in open holes. Under similar water/heave conditions, the compensator system reduces tool displacement by 50-60 %, or 75-84 % variance in downhole tool motion during normal logging operations. Such compensation efficiency (CE) is comparable to previous compensation systems, but using advanced and upgradeable technologies, and provides 50-85 % heave motion and heave variance attenuation. Moreover, logging down/up at low speeds (300-600 m/h) reduces the system's CE values by 15-20 %, and logging down at higher speeds (1,000-1,200 m/h) eliminates CE values by 55-65 %. Considering the high quality of the logging data collected, it is concluded that the new system can provide an improved level of compensation over previous systems. Also, if practically feasible, future integration of downhole cable dynamics as an input feedback into the current system could further improve its compensation efficiency during logging operations.

  9. Methods for interpretation of tensor induction well logging in layered anisotropic formations

    Science.gov (United States)

    Peksen, Ertan

    One of the most challenging problems in the field of electromagnetic well logging is the development of interpretation methods for the characterization of conductivity anisotropy in an earth formation. Response of a triaxial electromagnetic induction well logging instrument is examined. This instrument detects three components of the magnetic field due to each of three transmitters for a total of nine signals. The conductivity anisotropy of the medium can be resolved from the instrument response. This information includes not only the vertical and horizontal conductivities, but also the orientation of the logging instrument axis with respect to the principal tensor axes. Formulas for the apparent horizontal and vertical conductivities, the apparent anisotropy coefficient, and the apparent relative deviation angle are introduced. A new method of induction logging based on electrical measurements is investigated. Electrical tensor components are studied in an unbounded, homogeneous, transversely isotropic, conductive medium. Low frequency asymptotic approximations of the analytical solution are derived. The important result is that by measuring the in-phase components of the electrical tensor, the principal values of the conductivity tensor can be obtained. The basic principles of tensor induction logging two-, three-, and multilayer anisotropic formations in vertical and deviated wells are examined by using numerical simulation of the tensor logs. A technique for correct reconstruction of the apparent conductivities of the anisotropic formations is introduced, based on application of a regularized Newton method. The method is fast and provides real time interpretation. The practical effectiveness of this technique for tensor induction log interpretation is illustrated using results of numerical experiments. The theoretical formulas for the tensor apparent conductivities of the transversely isotropic medium are studied and developed for an ideal tensor induction

  10. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 22 2010-07-01 2010-07-01 false Logging, sampling, and testing prior to new well operation. 146.66 Section 146.66 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) UNDERGROUND INJECTION CONTROL PROGRAM: CRITERIA AND STANDARDS Criteria and Standards Applicable to Class...

  11. EVALUATION OF AQUIFER CHARACTERISTICS IN ECHI, DELTA STATE, NIGERIA USING WELL LOGGING AND PUMPING TEST METHOD

    Directory of Open Access Journals (Sweden)

    Ochuko Anomohanran

    2013-01-01

    Full Text Available This study was carried out to evaluate the aquifer characteristics of groundwater at Echi, Delta State, Nigeria. This was carried out by conducting electrical resistivity and spontaneous potential loggings in a drilled well at the study location. Pumping test using a one kilowatt pumping machine was carried out in the well. The logs were interpreted while the record of the pumping test was analysed using the Jacob straight line method. The result showed that five lithologic formations which are lateritic sand, clay, fine sand, medium grain sand and coarse sand exist in the area and that groundwater exist in the third, fourth and fifth formations. The analysis of the log record showed that the water quality increased with respect to the depth of the well. The value of the conductivity of the aquifer obtained from the analysis of the log record was 5.8×10-3 mS/m while the transmissivity was obtained as 86.0 m2/day. The specific capacity of the aquifer was obtained as 0.258. These values obtained from the test well revealed that the aquifer contained good quality water suitable for drinking and other purposes.

  12. Well-log based prediction of temperature models in the exploration of sedimentary settings

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea; Wonik, Thomas

    ) developed for matrix TC of sedimentary rocks. The equations resulted from a statistical analysis of an artificial set of mineral assemblages (consisting of 15 rock-forming minerals) typical for the different types of sedimentary rocks. The matrix TC was transformed into bulk TC by using a well-log derived...

  13. Analysis and Summary of Historical Dry Well Gamma Logs for S Tank Farm 200 West

    Energy Technology Data Exchange (ETDEWEB)

    MYERS, D.A.

    1999-11-22

    Gross gamma ray logs, recorded from January 1975 through mid-year 1994 as part of the Single-Shell Tank Farm Dry Well Surveillance Program, have been reanalyzed for the S tank farm to locate the presence of mobile radionuclides in the subsurface.

  14. Porosity prediction of I-field in the Niger delta area using well-log ...

    African Journals Online (AJOL)

    Porosity prediction of I-field in the Niger delta area using well-log data and ... There are many important characteristics of formations within the subsurface that can ... and 4.8186oN, longitudes 6.9595oE and 6.9800oE. Variogram analysis and ...

  15. Sample descriptions and summary logs of selected wells within the Hanford Reservation

    Energy Technology Data Exchange (ETDEWEB)

    Summers, W.K.; Hanson, R.T.

    1977-01-01

    This report presents the description and summary logs of cuttings samples from 114 wells and test holes drilled within the Hanford Reservation. Written descriptive matter as required, including color, fossils, trace constituents, total drilled depth, and any other nonstandard features observed is included.

  16. Oil and gas wells of Afghanistan with well logs (welllogafg.shp)

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — This shapefile contains points that describe the location of hydrocarbon exploration and production wells drilled in Afghanistan; and hyperlinks to scanned images of...

  17. Simulation of Electromagnetic Wave Logging Response in Deviated Wells Based on Vector Finite Element Method

    Institute of Scientific and Technical Information of China (English)

    LV Wei-Guo; CHU Zhao-Tan; ZHAO Xiao-Qing; FAN Yu-Xiu; SONG Ruo-Long; HAN Wei

    2009-01-01

    The vector finite element method of tetrahedral elements is used to model 3D electromagnetic wave logging response. The tangential component of the vector field at the mesh edges is used as a degree of freedom to overcome the shortcomings of node-based finite element methods. The algorithm can simulate inhomogeneous media with arbitrary distribution of conductivity and magnetic permeability. The electromagnetic response of well logging tools are studied in dipping bed layers with the borehole and invasion included. In order to simulate realistic logging tools, we take the transmitter antennas consisting of circular wire loops instead of magnetic dipoles. We also investigate the apparent resistivity of inhomogeneous formation for different dip angles.

  18. Magnetic Logs from the Lopra-1/1A and Vestmanna-1 wells (Faroe Islands)

    DEFF Research Database (Denmark)

    Waagstein, R.; Abrahamsen, N.

    2006-01-01

      Susceptibility results from cores (representing basalt, lapilli-tuffs and tuffs) and magnetic logs from the Lopra-1/1A well are presented. The basalts fall into a high- and a low-susceptibility group with no overlap. The high-susceptibility basalts (7 cores) have susceptibilities between 4 and 85...... the high-susceptibility basalts. The susceptibility of 9 volcaniclastites of lapilli-tuff or tuff varies from 0.4 to 4 x 10-3 SI. The cores reveal a bimodal distribution of magnetic susceptibily in the Lopra well. Low susceptibilities ranging from 0.4 to 4 in the well  are characteristic to both altered...... basalts poor in magnetite, lapilli-tuffs and tuffs. Thus single measurements of susceptibility are of little use in discriminating between these three types of rock. Susceptibility logs from the Lopra-1/1A  well show that the variation below 3315 m clearly distinguishes between volcaniclastics...

  19. Application of just-in-time manufacturing techniques in radioactive source in well logging industry

    Directory of Open Access Journals (Sweden)

    Atma Yudha Prawira

    2017-03-01

    Full Text Available Nuclear logging is one of major areas of logging development. This paper presents an empirical investigation to bring the drilling and completion of wells from an ill-defined art to a refined sci-ence by using radioactive source to “look and measure” such as formation type, formation dip, porosity, fluid type and numerous other important factors. The initial nuclear logging tools rec-ords the radiation emitted by formation as they were crossed by boreholes. Gamma radiation is used in well logging as it is powerful enough to penetrate the formation and steel casing. The ra-dioactive source is reusable so that after engineer finished the job the radioactive source is sent back to bunker. In this case inventory level of radioactive source is relatively high compared with monthly movement and the company must spend large amount of cost just for inventory. After calculating and averaging the monthly movement in 2014 and 2015, we detected a big pos-sibility to cut the inventory level to reduce the inventory cost.

  20. Characterization of a complex near-surface structure using well logging and passive seismic measurements

    Science.gov (United States)

    Benjumea, Beatriz; Macau, Albert; Gabàs, Anna; Figueras, Sara

    2016-04-01

    We combine geophysical well logging and passive seismic measurements to characterize the near-surface geology of an area located in Hontomin, Burgos (Spain). This area has some near-surface challenges for a geophysical study. The irregular topography is characterized by limestone outcrops and unconsolidated sediments areas. Additionally, the near-surface geology includes an upper layer of pure limestones overlying marly limestones and marls (Upper Cretaceous). These materials lie on top of Low Cretaceous siliciclastic sediments (sandstones, clays, gravels). In any case, a layer with reduced velocity is expected. The geophysical data sets used in this study include sonic and gamma-ray logs at two boreholes and passive seismic measurements: three arrays and 224 seismic stations for applying the horizontal-to-vertical amplitude spectra ratio method (H/V). Well-logging data define two significant changes in the P-wave-velocity log within the Upper Cretaceous layer and one more at the Upper to Lower Cretaceous contact. This technique has also been used for refining the geological interpretation. The passive seismic measurements provide a map of sediment thickness with a maximum of around 40 m and shear-wave velocity profiles from the array technique. A comparison between seismic velocity coming from well logging and array measurements defines the resolution limits of the passive seismic techniques and helps it to be interpreted. This study shows how these low-cost techniques can provide useful information about near-surface complexity that could be used for designing a geophysical field survey or for seismic processing steps such as statics or imaging.

  1. Addendum 2: Logs of monitor wells drilled May 1988 through December 1992

    Energy Technology Data Exchange (ETDEWEB)

    Stout, J. [Ray Raskin Associates Inc., Tempe, AZ (United States); Qualheim, B. [Lawrence Livermore National Lab., CA (United States); McPherrin, R. [Lawrence Livermore National Lab., CA (United States); Barber, K. [Allied Signal Technical Services, Livermore, CA (United States); Hedegaard, R. [ICF Kaiser Engineers, San Francisco, CA (United States); McConihe, W.; Miller, T. [Brown and Caldwell, Pleasanton, CA (United States)

    1993-11-01

    The logs in this addendum were plotted in a new format by the same software package (LOGGER by Rockware, Denver, CO) that was used in the original publication. The scale remains the same, 1 inch = 15 foot. The header is totally automated with a subheading indexing the well-construction symbols. Geophysical curves are labeled in their respective channels, and percentage core recovery is plotted in a histogram. Lithologic symbols are plotted to scale in a channel similar to previous logs. The lithologic description also has been automated to assure consistency in terminology. Descriptions are more extensive and are referenced by leader lines to the lithologic symbol. Additional figures included for this Addendum are: a plot of all the monitoring well locations at the LLNL Main site and a plot detailing the gasoline spill area well locations in the vicinity of Building 403.

  2. Volcanic stratigraphy of DSDP/ODP Hole 395A: An interpretation using well-logging data

    Science.gov (United States)

    Bartetzko, Anne; Pezard, Philippe; Goldberg, David; Sun, Yue-Feng; Becker, Keir

    2001-03-01

    Deep Sea Drilling Project/Ocean Drilling Program Hole 395A was drilled approximately 500 m deep into young oceanic crust west of the Mid-Atlantic Ridge. Core recovery is very poor in this hole and therefore continuous downhole measurements are important to understand the drilled lithology. Geophysical downhole measurements were carried out during several cruises. A new set of logs was recorded during Leg 174B in summer 1997. The new logging data show a significant improvement in data quality compared to older measurements from Leg 109. The lithostratigraphy established from cores gives only limited information because of the poor core recovery in this hole. The gaps in the core lithostratigraphy are filled by reconstructing a synthetic lithological profile using the standard well-logging data. Three types of lava morphologies, massive basalts, altered lava flows, and pillow basalts, may be distinguished using the logs because the lava morphologies show differences in their physical properties due to differences in fracturing and alteration. The synthetic lithological profile gives a more detailed and precise vertical definition of single layers than the core profile. The integration of further logging and core data enables a detailed reconstruction of the accretion history at the drill site. Cyclic, upward decreasing trends in the resistivity logs were already observed during earlier cruises and were referred to magmatic cycles. Similar trends occur in the density log and, inversely, in the total gamma ray log. The trends reflect gradual changes in fracturing, porosity, permeability, and alteration and cover depth intervals of several tens of meters. Boundaries between cycles are interpreted to correspond to periods of volcanic quiescence. Two types of boundaries may be identified. Boundaries correlating with reversals in the magnetic field and/or changes in the geochemical composition of the basalts are interpreted as long pauses. Basalts separated by these

  3. Temperature logging of groundwater in bedrock wells for geothermal gradient characterization in New Hampshire, 2012

    Science.gov (United States)

    Degnan, James; Barker, Gregory; Olson, Neil; Wilder, Leland

    2012-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater in deep bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. All wells selected for the study had low water yields, which correspond to low groundwater flow from fractures. This reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study were privately owned, and permission to use the wells was obtained from homeowners before logging.

  4. Heterogeneity analysis of geophysical well-log data using Hilbert-Huang transform

    Science.gov (United States)

    Gairola, Gaurav S.; Chandrasekhar, E.

    2017-07-01

    Geophysical well-log data manifest nonlinear behaviour of their respective physical properties of the subsurface layers as a function of depth. Therefore, nonlinear data analysis techniques must be used to understand and characterize the nature of the subsurface lithologies, vis-à-vis their degree of heterogeneity. One such nonlinear technique is the fully data adaptive Hilbert-Huang Transform (HHT), which constitutes two independent techniques, namely, the empirical mode decomposition technique (EMDT) and the Hilbert spectral analysis (HSA). While EMDT facilitates to decompose the well-log data into oscillatory signals of different wavelengths called intrinsic mode functions (IMFs), which represent different frequency characteristics of the signal and which in turn helps to calculate the degree of heterogeneity in the subsurface, the HSA facilitates to determine the instantaneous amplitudes and frequencies of the IMFs, which can be used to characterize the heterogeneity in the signals. In this study, HHT has been applied to gamma-ray log of the thickest limestone reservoir zones of two different wells: Well B and Well C, located in the western offshore basin of India to determine the respective IMFs. The estimated instantaneous amplitudes and frequencies of the derived IMFs by HSA qualitatively suggested well C to be more heterogeneous than well B. By establishing a relationship between the IMF number (m) and its mean wavelength (Im), a heterogeneity index (ρ) associated with subsurface layers was determined using Im = kρm, where ' k' is a constant. ρ bears an inverse relation with the heterogeneity of the subsurface. The estimated ρ values confirm our observations from HSA. We attribute the higher degree of heterogeneity in Well C to high average shale volume in the limestone reservoir zone in Well C than in Well B. Interpretation of the results together with those of the heterogeneity analysis of the gas zone in limestone reservoir of Well C is made by

  5. Statistical factor analysis technique for characterizing basalt through interpreting nuclear and electrical well logging data (case study from Southern Syria).

    Science.gov (United States)

    Asfahani, Jamal

    2014-02-01

    Factor analysis technique is proposed in this research for interpreting the combination of nuclear well logging, including natural gamma ray, density and neutron-porosity, and the electrical well logging of long and short normal, in order to characterize the large extended basaltic areas in southern Syria. Kodana well logging data are used for testing and applying the proposed technique. The four resulting score logs enable to establish the lithological score cross-section of the studied well. The established cross-section clearly shows the distribution and the identification of four kinds of basalt which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The factor analysis technique is successfully applied on the Kodana well logging data in southern Syria, and can be used efficiently when several wells and huge well logging data with high number of variables are required to be interpreted.

  6. Drillers' logs of wells in the Hanford reservation. Volume I

    Energy Technology Data Exchange (ETDEWEB)

    Summers, W.K.; Schwab, G.

    1977-01-01

    More than 3000 wells and test holes have been drilled within the Hanford Reservation. Information on these wells range from complete sample suites complemented by bore hole geophysical studies to no record at all. Often the driller's log is the only record available for a well. This report is a product of the continuing project aimed at quantifying the hydraulic parameters of the synthetic flow system of the Hanford Reservation. The subsurface geology of the Hanford Reservation must be understood before the hydrologic parameters of the rocks can be estimated with any accuracy. To refine the state of our knowledge of the hydrologic regime all available data concerning the reservation geology must be considered and evaluated. Transcriptions are presented of 417 drillers' logs. This compilation includes every original driller's report we could obtain for the 600, 1100, and 3000 areas of the Hanford Reservation, but only a few logs from each of the 100, 200, and 300 areas where holes are very close together. The standard format consists of two parts: a heading that gives the general information for the well, and the description of the material penetrated.

  7. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria.

    Science.gov (United States)

    Asfahani, Jamal

    2011-03-01

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  8. Basalt characterization by means of nuclear and electrical well logging techniques. Case study from Southern Syria

    Energy Technology Data Exchange (ETDEWEB)

    Asfahani, Jamal, E-mail: cscientific2@aec.org.s [Atomic Energy Commission, P.O. Box 6091, Damascus (Syrian Arab Republic)

    2011-03-15

    Nuclear well logging, including natural gamma ray, density, and neutron-porosity techniques are used with electrical well logging of long and short normal techniques to characterize the basaltic areas largely extended in Southern Syria. Statistical analysis approach with the threshold concept has been adapted for such characterization, where four kinds of basalt have been identified: very hard basalt, hard basalt, fractured basalt, and basalt alteration products. The spectrometric gamma technique has also been applied on the retrieved rock samples in order to determine the radioactive content (eU, eTh, and K%) of the basaltic section in the study area. No radioactive anomalies have been detected, the radioactive values are normal and in the expected range.

  9. Experimental approaches for the development of gamma spectroscopy well logging system

    Energy Technology Data Exchange (ETDEWEB)

    Shin, Jehyun; Hwang, Seho; Kim, Jongman [Korea Institute of Geoscience and Mineral Resources (124 Gwahang-no, Yuseong-gu, Daejeon, Korea) (Korea, Republic of); Won, Byeongho [Heesong Geotek Co., Ltd (146-8 Sangdaewon-dong, Jungwon-gu, Seongnam-si, Gyeonggi-do, Korea) (Korea, Republic of)

    2015-03-10

    This article discusses experimental approaches for the development of gamma spectroscopy well logging system. Considering the size of borehole sonde, we customize 2 x 2 inches inorganic scintillators and the system including high voltage, preamplifier, amplifier and multichannel analyzer (MCA). The calibration chart is made by test using standard radioactive sources so that the measured count rates are expressed by energy spectrum. Optimum high-voltage supplies and the measurement parameters of each detector are set up by experimental investigation. Also, the responses of scintillation detectors have been examined by analysis according to the distance between source and detector. Because gamma spectroscopy well logging needs broad spectrum, high sensitivity and resolution, the energy resolution and sensitivity as a function of gamma ray energy are investigated by analyzing the gamma ray activities of the radioactive sources.

  10. THE CAMAQUÃ BASIN MODELLING : TECTONOSTRATIGRAPHY THROUGH INTEGRATION OF GEOPHYSICAL (GRAVIMETRY, WELL LOG AND REMOTE SENSING DATA

    Directory of Open Access Journals (Sweden)

    Gómez Londoño Ernesto

    2007-06-01

    Full Text Available A tectonostratigraphic study of the Camaquã Basin, formed by Neoproterozoic to Eopaleozoic volcano-sedimentary units, is herein presented. Based on lineaments obtained through LANDSAT
    TM images and geophysical methods, four structural domains were recognized. The depositional and deformational sequences of the Guaritas and the Bom Jardim Formations were identified on
    well logs, where the fluvial deltaic system and brittle to brittle-ductile tectonic evidence is preserved. Differential compaction of sedimentary rocks was recognized using geophysical information (electrical (well log and potential methods (gravimetry. The sedimentary package presents variable thickness, increasing to the NE portion of the basin, and a compartmentalization in echelon subbasins, delimited by NW-trending structures is observed. A 3D schematic model of the Camaquã Basin was built based on the geophysical and satellite image data integrated to the Digital Terrane Model.

  11. Evaluation of Non-Nuclear Techniques for Well Logging: Final Report

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Leonard J.; Griffin, Jeffrey W.; Harris, R. V.; Denslow, Kayte M.; Moran, Traci L.

    2011-08-01

    The focus of this study is the understanding of the technical obstacles that hinder the replacement of and the disadvantages from the loss of extensive interpretation experience based on data accumulated with AmBe. Enhanced acoustic and electromagnetic sensing methods in combination with non-isotope-based well logging techniques have the potential to complement and/or replace existing isotope-based techniques, providing the opportunity to reduce oil industry dependence on isotopic sources such as AmBe.

  12. New Relations of Water Saturation’s Calculus from Well Logs

    Directory of Open Access Journals (Sweden)

    Malureanu Ion

    2016-10-01

    Full Text Available The saturation in water or hydrocarbon is an important petrophysical parameter used for the evaluation of oil and gas reservoirs. It represents the amount of hydrocarbons in a reservoir. There are many relations to determine the water saturation from well logs by using the physical properties of rocks. The accurate determination of the hydrocarbon formation or the water saturation is given by the accuracy of the parameters used for calculating and by the relations used.

  13. Fluid flow model of the Cerro Prieto Geothermal Field based on well log interpretation

    Energy Technology Data Exchange (ETDEWEB)

    Halfman, S.E.; Lippmann, M.J.; Zelwe, R.; Howard, J.H.

    1982-08-10

    The subsurface geology of the Cerro Prieto geothermal field was analyzed using geophysical and lithologic logs. The distribution of permeable and relatively impermeable units and the location of faults are shown in a geologic model of the system. By incorporating well completion data and downhole temperature profiles into the geologic model, it was possible to determine the direction of geothermal fluid flow and the role of subsurface geologic features that control this movement.

  14. Igneous rocks identification on well-log data; Classificacao de rochas igneas em perfis eletricos

    Energy Technology Data Exchange (ETDEWEB)

    Souza-Lima, Wagner [PETROBRAS S.A., Salvador, BA (Brazil). Unidade de Negocio de Exploracao e Producao de Sergipe e Alagoas. Ativo de Exploracao], E-mail: wagnersl@petrobras.com.br; Pinho, Gustavo de Carvalho; Silva, Patricia Martins; Paraizo, Paulo Lopes Brandao

    2005-11-15

    An attempt to discriminate and characterise igneous rocks on well-log data is made in a well drilled on the Cabo Sub-basin (JG-1 well, Sergipe- Alagoas Basin), situated on the northeastern coast of Brazil. Log data from the twelve drilled igneous intervals were analysed on RHOBxPHIN and DTxGRxResistivity cross plots. Similar diagrams were constructed for igneous data from the 1-CPE-1-PE well, drilled on the same basin, and with igneous data from other Brazilian basins. At the RHOBxPHIN cross plot, twelve lithologic fields were discriminated, and their characteristics verified against petrographic data. Two trends are perceptible: the basic rocks set (olivine-basalt, andesite, basaltic pumice and basaltic andesite) distributed along the dolomite line, and the acid rocks set (trachyandesite/quartz-latite, trachyandesite, trachyte, olivine-trachyandesite and acid pumice) coincident with the calcite line. At the DTxGRxResistivity cross plot, the basic set occurs around low-GR field, and the acid set is distributed around high-GR field. The JG-1 well's log data were submitted to discriminant analysis, and the results were checked against the CPE-1 well's curves, for validation. For the first well, the hits ranged from 82 and 100%. For the second well, a perfect lithologic identification was obtained, except for those cases where the lithotypes does not exist in the JG-1 well. One of the main applications for this technique is the stratigraphic correlation for the volcanic successions from sedimentary basins, mainly in the absence of good biostratigraphic markers. (author)

  15. Expected-value techniques for Monte Carlo modeling of well logging problems

    Energy Technology Data Exchange (ETDEWEB)

    Mosher, Scott W. [Claremont Research Institute of Applied Mathematical Sciences, School of Mathematics, Claremont Graduate University, Claremont, CA 91711 (United States); Maucec, Marko, E-mail: marko.maucec@halliburton.co [Claremont Research Institute of Applied Mathematical Sciences, School of Mathematics, Claremont Graduate University, Claremont, CA 91711 (United States); Spanier, Jerome [Claremont Research Institute of Applied Mathematical Sciences, School of Mathematics, Claremont Graduate University, Claremont, CA 91711 (United States); Badruzzaman, Ahmed; Chedester, Clint [ChevronTexaco Energy Technology Company, 6001 Bollinger Canyon Road, D-2208, San Ramon, CA 94583 (United States); Evans, Michael [Schlumberger, 110 Gillingham Lane, Sugar Land, TX 77478 (United States)

    2010-02-01

    This article describes research performed to develop an expected-value (EV) estimation capability for improving the efficiency of Monte Carlo simulations of oil well logging problems. The basic idea underlying EV estimation is that event-level interaction and transport probabilities are known and can be averaged exactly to produce unbiased estimators that properly account for potential future events in the simulation. Conventional surface-crossing and track-length based estimators do not provide any information unless a particle history actually reaches a detector region. Expected-value estimators, however, can extract information from particles that merely travel along a direction intercepting the detector region. This paper describes two expected-value estimators that have been developed for oil well logging simulations. The first estimates the volume-averaged scalar flux or reaction rate in a detector. The second estimates a weighted surface-averaged incident current that can be enfolded with a detector response function to estimate pulse-height spectra. Though EV estimation reduces variance at the event level, it does not guarantee reduced variance at the history level. However, our oil well logging tests indicate that the EV approach generally improves information content, enhances the efficiency of the transport simulation, and provides an efficient technique to obtain the fluxes, reaction rates, and pulse-height spectra in detectors, especially when applied in conjunction with weight-window variance reduction techniques.

  16. A new method for permeability estimation from conventional well logs in glutenite reservoirs

    Science.gov (United States)

    Shen, Bo; Wu, Dong; Wang, Zhonghao

    2017-10-01

    Permeability is one of the most important petrophysical parameters in formation evaluation. In glutenite reservoirs, the traditional permeability estimation method from conventional well logs cannot provide satisfactory results due to the characteristic of strong heterogeneity resulting from the wide variety of clastic grains and the extremely complex percolation network. In this paper, a new method for estimating permeability from conventional well logs is developed. On the basis of previous research, a simple method for estimating the flowing porosity of the Maxwell conductive model via well logs is proposed and then a ‘flowing permeability’ equation is established by using the equivalent parameters of geometry and flowing porosity. The form is similar to that of the Kozeny–Carman model for characterizing permeability. Based on the Maxwell conductive model, threshold theory, conductive efficiency theory and core analysis data, a new method to calculate the permeability of glutenite reservoirs by using float porosity is built up through deduction and analysis of the Kozeny–Carman equation, and field application to a glutenite reservoir shows that the result of the proposed method in this paper is accurate and reasonable.

  17. Algorithm for well logging data standardization%测井资料标准化算法

    Institute of Scientific and Technical Information of China (English)

    尚景涛; 刘英明; 武盟盟

    2014-01-01

    Through a combination of mean-variance and frequency histogram, the well logging data. By calculating the correlation of the data was standardized, the correction of the curve was automatically calculated by the mean-variance method. And then through overlap of the frequency histogram, the amount of fine tuning was determined manually. Practical application shows that the proposed method can standardize the well logging data quickly and effectively, which provides certain reference value for the well logging interpretation.%采用均值方差与频率直方图相结合的方法对测井资料作标准化处理。通过测井数据之间的相关性,利用均值-方差法自动计算相应待校正曲线的校正量,然后通过频率直方图的重叠情况,手工确定微调量。实际应用表明,该方法能够快速、有效地对测井资料进行标准化,为测井解释提供一定的参考价值。

  18. Interpretation method for hot spring well logging data; Onsensei no butsuri kenso

    Energy Technology Data Exchange (ETDEWEB)

    Fujiwara, C. [Techno Rent Co. Ltd., Tokyo (Japan); Sato, T. [Shiga Boring Co., Nagano (Japan); Matsuoka, K. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan); Aizawa, K. [Tone Co. Ltd., Tokyo (Japan)

    1996-10-01

    Basic problems in the interpretation of hot spring well logging data are discussed, and report is made on the result of effective analysis obtained experimentally based on many on-the-spot data. Interpretation of hydraulic properties of hot spring aquifers is discussed based on electrical and temperature logging data obtained at hot spring wells in Japan. As a result of many case studies, it is found that a reservoir can be evaluated roughly by the value of the specific resistance coefficient of the bed even when there is no temperature abnormality on the logging curve. It has been known by ground water investigation that the specific resistance of aquifer is almost proportionate to the specific resistance of ground water, but such simple relationship can not be found for hot spring wells because of extremely large electric conductivity of hot water, profound alteration of beds, or fracture development. However, it is found from the case study that the specific resistance coefficient of the bed is significant for the evaluation of reservoirs. 10 refs., 9 figs.

  19. Records of selected wells and lithologic logs of test holes, Hendry County and adjacent areas, Florida

    Science.gov (United States)

    Fish, John E.; Causaras, Carmen R.; O'Donnell, T. H.

    1983-01-01

    To provide water-resource information for Hendry County, Florida , geologic test holes were drilled in the surficial aquifer, and an extensive inventory was compiled of wells in the surficial aquifer and deep artesian aquifers. This report provides: (1) records for 788 selected wells and test holes including location , construction, water use, water level, chloride concentration, specific conductance, temperature, yield, hydrogen sulfide, and iron-staining problems; and (2) lithologic logs for 26 test holes ranging in depth from 90 to 650 feet. A few inventoried wells and two test holes are in adjacent parts of Collier or Glades Counties. (USGS)

  20. Simulation Experiments in Electromagnetic Tomography Well Logging in Two-phase flow

    Institute of Scientific and Technical Information of China (English)

    Wu Xiling; Zhao Yanwei

    2006-01-01

    Electromagnetic Computer Tomography (ECT) is a method to probe the interior of an inhomogeneous medium via surface measurement in a non-linear way. Due to the great differences in conductivity and permittivity between oil and water in the well, Electromagnetic Tomography Well Logging (ETWL), a new flow imaging measurement system, is proposed to describe the distribution and movement of oil/water two-phase flow in the well by scanning the detected region and applying a suitable data processing algorithm. The results of the numerical simulation and physical modeling show that the system could provide a clear image of the flow profile.

  1. Integrated analysis of well logs and seismic data to estimate gas hydrate concentrations at Keathley Canyon, Gulf of Mexico

    Science.gov (United States)

    Lee, M.W.; Collett, T.S.

    2008-01-01

    Accurately detecting and quantifying gas hydrate or free gas in sediments from seismic data require downhole well-log data to calibrate the physical properties of the gas hydrate-/free gas-bearing sediments. As part of the Gulf of Mexico Joint Industry Program, a series of wells were either cored or drilled in the Gulf of Mexico to characterize the physical properties of gas hydrate-bearing sediments, to calibrate geophysical estimates, and to evaluate source and transport mechanisms for gas within the gas hydrates. Downhole acoustic logs were used sparingly in this study because of degraded log quality due to adverse wellbore conditions. However, reliable logging while drilling (LWD) electrical resistivity and porosity logs were obtained. To tie the well-log information to the available 3-D seismic data in this area, a velocity log was calculated from the available resistivity log at the Keathley Canyon 151-2 well, because the acoustic log or vertical seismic data acquired at the nearby Keathley Canyon 151-3 well were either of poor quality or had limited depth coverage. Based on the gas hydrate saturations estimated from the LWD resistivity log, the modified Biot-Gassmann theory was used to generate synthetic acoustic log and a synthetic seismogram was generated with a fairly good agreement with a seismic profile crossing the well site. Based on the well-log information, a faintly defined bottom-simulating reflection (BSR) in this area is interpreted as a reflection representing gas hydrate-bearing sediments with about 15% saturation overlying partially gas-saturated sediments with 3% saturation. Gas hydrate saturations over 30-40% are estimated from the resistivity log in two distinct intervals at 220-230 and 264-300 m below the sea floor, but gas hydrate was not physically recovered in cores. It is speculated that the poor recovery of cores and gas hydrate morphology are responsible for the lack of physical gas hydrate recovery.

  2. Well log interpretation and seismic character of the cenozoic sequence in the northern Alboran Sea

    Science.gov (United States)

    Jurado, M. J.; Comas, M. C.

    1992-06-01

    Seismic stratigraphic and main lithological features of the sedimentary cover overlying the basement of the Alboran Sea were established via the analysis of commercial multichannel seismic surveys, geophysical well logs, and well data. Six seismic stratigraphics units (VI to I), bounded by unconformities, form the marine sediments that range in age from early Miocene to Quaternary. They are dated by extrapolation of commercial drilling results from the northern Alboran Sea. Volcanic activity is recorded within sedimentary sequences of units V to II. Undercompaction features are detected in the two basal units.

  3. Geological structure guided well log interpolation for high-fidelity full waveform inversion

    Science.gov (United States)

    Chen, Yangkang; Chen, Hanming; Xiang, Kui; Chen, Xiaohong

    2016-11-01

    Full waveform inversion (FWI) is a promising technique for inverting a high-resolution subsurface velocity model. The success of FWI highly depends on a fairly well initial velocity model. We propose a method for building a good initial velocity model that can be put into the FWI framework for inverting a nearly perfect velocity structure. We use a well log interpolated velocity model as a high-fidelity initial model for the subsequent FWI. The interpolation problem is solved via a least-squares method with a geological structural regularization. In order to obtain the geological structure of subsurface reflectors, an initial reverse time migration (RTM) with a fairly realistic initial velocity model is conducted, and the local slope of subsurface structure is roughly calculated from the RTM image. The well log interpolated initial velocity model can be very close to the true velocity while containing a small velocity anomaly or oversmoothing caused by the imperfect velocity interpolation. The anomaly and oversmoothing effect can be compensated during the subsequent FWI iterations. We use a relatively simple-layered model and the more complicated Marmousi velocity model to demonstrate the applicability of the proposed approach. We start from a very smooth velocity model and obtain a nearly perfect FWI result which is much better than the traditional FWI result without the velocity interpolation. The migrated images from the RTM method using different velocity models are also compared to further confirm the effectiveness of the proposed framework. Regarding the field deployment, we suggest that future drilling of exploration wells can be seismic-oriented, which can help fully utilize the information of well logs for building initial subsurface velocity model and will facilitate a wide application of the proposed methodology.

  4. Integration between well logging and seismic reflection techniques for structural a

    Science.gov (United States)

    Mohamed, Adel K.; Ghazala, Hosni H.; Mohamed, Lamees

    2016-12-01

    Abu El Gharadig basin is located in the northern part of the Western Desert, Egypt. Geophysical investigation in the form of thirty (3D) seismic lines and well logging data of five wells have been analyzed in the oil field BED-1 that is located in the northwestern part of Abu El Gharadig basin in the Western Desert of Egypt. The reflection sections have been used to shed more light on the tectonic setting of Late Jurassic-Early Cretaceous rocks. While the well logging data have been analyzed for delineating the petrophysical characteristics of the two main reservoirs, Bahariya and Kharita Formations. The constructed subsurface geologic cross sections, seismic sections, and the isochronous reflection maps indicate that the area is structurally controlled by tectonic trends affecting the current shape of Abu El Gharadig basin. Different types of faults are well represented in the area, particularly normal one. The analysis of the average and interval velocities versus depth has shown their effect by facies changes and/or fluid content. On the other hand, the derived petrophysical parameters of Bahariya and Kharita Formations vary from well to another and they have been affected by the gas effect and/or the presence of organic matter, complex lithology, clay content of dispersed habitat, and the pore volume.

  5. Integration between well logging and seismic reflection techniques for structural a

    Directory of Open Access Journals (Sweden)

    Adel K. Mohamed

    2016-12-01

    Full Text Available Abu El Gharadig basin is located in the northern part of the Western Desert, Egypt. Geophysical investigation in the form of thirty (3D seismic lines and well logging data of five wells have been analyzed in the oil field BED-1 that is located in the northwestern part of Abu El Gharadig basin in the Western Desert of Egypt. The reflection sections have been used to shed more light on the tectonic setting of Late Jurassic–Early Cretaceous rocks. While the well logging data have been analyzed for delineating the petrophysical characteristics of the two main reservoirs, Bahariya and Kharita Formations. The constructed subsurface geologic cross sections, seismic sections, and the isochronous reflection maps indicate that the area is structurally controlled by tectonic trends affecting the current shape of Abu El Gharadig basin. Different types of faults are well represented in the area, particularly normal one. The analysis of the average and interval velocities versus depth has shown their effect by facies changes and/or fluid content. On the other hand, the derived petrophysical parameters of Bahariya and Kharita Formations vary from well to another and they have been affected by the gas effect and/or the presence of organic matter, complex lithology, clay content of dispersed habitat, and the pore volume.

  6. Lacunarity of geophysical well logs in the Cantarell oil field, Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Arizabalo, Ruben Dario [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Oleschko, Klavdia [Centro de Geociencias, Universidad Nacional Autonoma de Mexico, Juriquilla, Queretaro (Mexico); Korvin, Gabor [King Fahd University, Dhahran (Saudi Arabia); Lozada, Manuel [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico); Castrejon, Ricardo [Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico); Ronquillo, Gerardo [Instituto Mexicano del Petroleo, Mexico, D.F. (Mexico)

    2006-04-15

    Lacunarity and fractal variations in geophysical well logs are associated with stratigraphic and petrophysical properties of the naturally fractured Cantarell field in the Gulf of Mexico. Neutron porosity (NPHI), density (RHOB, DRHO, PEF), resistivity (LLD, LLS, MSFL), natural radioactivity (GR, CGR, URAN, POTA, THOR) and caliper (CALI) logs are studied. The resistivity logs yielded remarkably high lacunarity values, especially in the hydrocarbon source- and reservoir rocks. Lacunarity {delta} was found to depend on the resolution and radial depth of penetration of the logging method. It systematically increased in the following order: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD). [Spanish] En este trabajo fueron analizadas las variaciones fractales y de lagunaridad de los registros geofisicos de pozo, con el fin de asociarlos con las propiedades estratigraficas y petrofisicas del yacimiento naturalmente fracturado de Cantarell, en el Golfo de Mexico. Los registros considerados fueron: porosidad neutron (NPHI), densidad (RHOB, DRHO, PEF), resistividad (LLD, LLS, MSFL), radiactividad natural (GR, CGR, URAN, POTA, THOR) y caliper (CALI). Los registros de resistividad produjeron valores de lagunaridad notablemente altos, especialmente en las rocas generadoras y almacenadoras, a diferencia de los demas registros, cuya homogeneidad de traza implico una baja lagunaridad. Los resultados indican que la lagunaridad observada depende de la resolucion y profundidad radial de penetracion del metodo geofisico estudiado y aumenta sistematicamente en el siguiente orden: {delta}(RHOB) < {delta}(CALI) < {delta}(PEF) < {delta}(URAN) < {delta}(GR) < {delta}(NPHI) < {delta}(POTA) < {delta}(CGR) < {delta}(THOR) < {delta}(MSFL) < {delta}(DRHO) < {delta}(LLS) < {delta}(LLD).

  7. Joint interpretation of magnetotelluric, seismic, and well-log data in Hontomín (Spain)

    Science.gov (United States)

    Ogaya, Xènia; Alcalde, Juan; Marzán, Ignacio; Ledo, Juanjo; Queralt, Pilar; Marcuello, Alex; Martí, David; Saura, Eduard; Carbonell, Ramon; Benjumea, Beatriz

    2016-06-01

    Hontomín (N of Spain) hosts the first Spanish CO2 storage pilot plant. The subsurface characterization of the site included the acquisition of a 3-D seismic reflection and a circumscribed 3-D magnetotelluric (MT) survey. This paper addresses the combination of the seismic and MT results, together with the available well-log data, in order to achieve a better characterization of the Hontomín subsurface. We compare the structural model obtained from the interpretation of the seismic data with the geoelectrical model resulting from the MT data. The models correlate well in the surroundings of the CO2 injection area with the major structural differences observed related to the presence of faults. The combination of the two methods allowed a more detailed characterization of the faults, defining their geometry, and fluid flow characteristics, which are key for the risk assessment of the storage site. Moreover, we use the well-log data of the existing wells to derive resistivity-velocity relationships for the subsurface and compute a 3-D velocity model of the site using the 3-D resistivity model as a reference. The derived velocity model is compared to both the predicted and logged velocity in the injection and monitoring wells, for an overall assessment of the computed resistivity-velocity relationships. The major differences observed are explained by the different resolution of the compared geophysical methods. Finally, the derived velocity model for the near surface is compared with the velocity model used for the static corrections in the seismic data. The results allowed extracting information about the characteristics of the shallow unconsolidated sediments, suggesting possible clay and water content variations. The good correlation of the velocity models derived from the resistivity-velocity relationships and the well-log data demonstrate the potential of the combination of the two methods for characterizing the subsurface, in terms of its physical properties

  8. Machine Learning for Mapping Groundwater Salinity with Oil Well Log Data

    Science.gov (United States)

    Chang, W. H.; Shimabukuro, D.; Gillespie, J. M.; Stephens, M.

    2016-12-01

    An oil field may have thousands of wells with detailed petrophysical logs, and far fewer direct measurements of groundwater salinity. Can the former be used to extrapolate the latter into a detailed map of groundwater salinity? California Senate Bill 4, with its requirement to identify Underground Sources of Drinking Water, makes this a question worth answering. A well-known obstacle is that the basic petrophysical equations describe ideal scenarios ("clean wet sand") and even these equations contain many parameters that may vary with location and depth. Accounting for other common scenarios such as high-conductivity shaly sands or low-permeability diatomite (both characteristic of California's Central Valley) causes parameters to proliferate to the point where the model is underdetermined by the data. When parameters outnumber data points, however, is when machine learning methods are most advantageous. We present a method for modeling a generic oil field, where groundwater salinity and lithology are depth series parameters, and the constants in petrophysical equations are scalar parameters. The data are well log measurements (resistivity, porosity, spontaneous potential, and gamma ray) and a small number of direct groundwater salinity measurements. Embedded in the model are petrophysical equations that account for shaly sand and diatomite formations. As a proof of concept, we feed in well logs and salinity measurements from the Lost Hills Oil Field in Kern County, California, and show that with proper regularization and validation the model makes reasonable predictions of groundwater salinity despite the large number of parameters. The model is implemented using Tensorflow, which is an open-source software released by Google in November, 2015 that has been rapidly and widely adopted by machine learning researchers. The code will be made available on Github, and we encourage scrutiny and modification by machine learning researchers and hydrogeologists alike.

  9. Scheme of the Saik computer system of complex automatic interpretation of well logging data

    Energy Technology Data Exchange (ETDEWEB)

    Frydecki, J.

    1975-01-01

    The basis of the first Polish interpretation system is the method of ''autocalibration.'' The input data for the system Saik are noncalibrated gamma log, neutron log, resistivity log, and caliper log. The input data are autocalibrated by means of correlation cross-plotting of gamma versus neutron, gamma versus resistivity and resistivity versus neutron logs. The results of processing are tables and curves reflecting clay content, porosity and hydrocarbon saturation.

  10. Fault zone properties in carbonate rocks: insights for well logs, core and field data

    Science.gov (United States)

    Giorgioni, Maurizio; Cilona, Antonino; Tondi, Emanuele; Agosta, Fabrizio

    2010-05-01

    In the last few years, numerous works addressed the deformation processes in carbonate rocks. These studies, generally sponsored by the oil industry, aimed to a better understanding of the structural and hydraulic properties of fault zones as well as of the subsurface fluid pathways in deformed carbonate rocks. This effort was mainly driven by the economic significance that carbonate rocks have for the oil industry, since they represent important natural reservoirs of hydrocarbons. According to the many field-based research scientific articles published in the recent past, both structural and hydraulic properties of fault zones, and their evolution trough time, exert a first order control on subsurface fluid flow and accumulation in fractured carbonate reservoirs. In order to convert this knowledge into predictive modeling tools that would help to optimize their exploitation, it should be useful to integrate the field-based data together with the subsurface data, which generally consist of core and well log (resistivity, acoustic, gamma ray etc.) analyses usually gathered to assess the formation evaluation of carbonate reservoir. The presented work aims at filling this cognitive gap by the acquisition and elaboration of subsurface geophysical properties of a hydrocarbon-bearing oblique normal fault zone characterized by 10's of m offset, and cropping out in an exposed analogue of fractured carbonate reservoir (Maiella Mountain, Italy). The deformation mechanisms associated to the processes of fault nucleation and development within the Oligo-Miocene shallow-water carbonate rocks were documented in the recent past by our research group. In this present contribution, we present the results of our elaboration of the geophysical data, obtained from well logs oriented perpendicular to the study fault zone. These results are consistent with the following statements: a) there is a meaningful correlations between cores and digital images; b) a detailed structural analysis

  11. Geophysical logging of bedrock wells for geothermal gradient characterization in New Hampshire, 2013

    Science.gov (United States)

    Degnan, James R.; Barker, Gregory; Olson, Neil; Wilder, Leland

    2014-01-01

    The U.S. Geological Survey, in cooperation with the New Hampshire Geological Survey, measured the fluid temperature of groundwater and other geophysical properties in 10 bedrock wells in the State of New Hampshire in order to characterize geothermal gradients in bedrock. The wells selected for the study were deep (five ranging from 375 to 900 feet and five deeper than 900 feet) and 6 had low water yields, which correspond to low groundwater flow from fractures. This combination of depth and low water yield reduced the potential for flow-induced temperature changes that would mask the natural geothermal gradient in the bedrock. All the wells included in this study are privately owned, and permission to use the wells was obtained from landowners before geophysical logs were acquired for this study. National Institute of Standards and Technology thermistor readings were used to adjust the factory calibrated geophysical log data. A geometric correction to the gradient measurements was also necessary due to borehole deviation from vertical.

  12. Gamma well-logging in burial ground of Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W.G.; Hofstetter, K.J.; MacMurdo, K.W. [Westinghouse Savannah River Company, Aiken, SC (United States)

    1995-12-31

    Gamma well-logging measurements were conducted in an inactive radioactive waste burial ground of the Savannah River site to appraise whether any evidence existed for downward movement of radioactivity toward the water table. Similar measurements on the same wells were conducted in 1980, providing a baseline from which to measure any changes in their radioactive plumes. In particular, the recent measurements sought to detect significant changes in depth location and radiation magnitude of the plumes, as well as the existence of any new plumes. By comparing measurements on a number of these wells, which were distributed on a grid pattern, it was anticipated that the general status of this section of the burial ground could be established.

  13. Space age telemetry for geothermal well logging: the wireline transmission link

    Energy Technology Data Exchange (ETDEWEB)

    Kolar, J.D.; Dennis, B.R.; Stephani, E.L.; Gutierrez, P.

    1985-01-01

    The development of aerospace telemetry has opened new communication data links for making measurements in deep boreholes in the earth's crust. However, now a transmission line must be used since high-frequency signals will not propagate through this medium. Further restrictions are imposed upon well-logging transmission lines in high-temperature boreholes. It is possible to extend the bandwidth and number of data channels to enhance measurements in geothermal boreholes by combining aerospace telemetry techniques with thermal protection systems and careful selection of wireline data transmission configurations. 5 refs., 2 figs.

  14. Laboratory simulation on acoustic well-logging with phased array transmitter

    Institute of Scientific and Technical Information of China (English)

    QIAOWenxiao; CHENXuelian; DUGuangsheng; FANGJun; LIGang

    2003-01-01

    Two small scale acoustic phased arrays with 4 elements have been designed and assembled in the laboratory. Experiments have been carried out with them. It is found that both directivity and radiation lobe width of the phased array can be regulated by changing the time delay between the input signals on neighboring elements. Results measured are in good agreement with those calculated. By using the phased array as an acoustic transmitter and hydrophone as a receiver, small scale acoustic well-logging simulations have been carried out both on an aluminum model well and on a concrete one. Experimental results show that, by increasing the time delay of the input signals on neighboring elements, the steered radiation angle of the phased array becomes larger and larger, and generation conditions of the refracted compressional wave and the refracted shear wave are reached successively, and the refracted compressional wave, the refracted shear wave and the Stoneley wave axe strengthened, respectively. Therefore, by choosing element spacing of a phased array and acoustic wave frequency appropriately, the main radiation lobe of the phased array can be widened to cover the first critical angle of all kinds of formations, which makes it possible to apply phased array acoustic well-logging in any formation continuously without regulating directivity of the phased array.

  15. Basalt identification by interpreting nuclear and electrical well logging measurements using fuzzy technique (case study from southern Syria).

    Science.gov (United States)

    Asfahani, J; Abdul Ghani, B; Ahmad, Z

    2015-11-01

    Fuzzy analysis technique is proposed in this research for interpreting the combination of nuclear and electrical well logging data, which include natural gamma ray, density and neutron-porosity, while the electrical well logging include long and short normal. The main objective of this work is to describe, characterize and establish the lithology of the large extended basaltic areas in southern Syria. Kodana well logging measurements have been used and interpreted for testing and applying the proposed technique. The established lithological cross section shows the distribution and the identification of four kinds of basalt, which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The fuzzy analysis technique is successfully applied on the Kodana well logging data, and can be therefore utilized as a powerful tool for interpreting huge well logging data with higher number of variables required for lithological estimations.

  16. Revisiting hydrostratigraphy in Bandung-Soreang groundwater basin: A well-logs re-analysis

    Science.gov (United States)

    Sunarwan, B.; Irawan, D. E.; Puradimaja, D. J.; Notosiswoyo, S.; Sadisun, I. A.; Setiawan, T.; Anugrah, R. M.

    2015-09-01

    An attempt to revisit the hydro-stratigraphy of Bandung-Soreang Groundwater Basin (BSGB) has been done based on 111 well-logging training dataset. Transformation of resistivity values from well-log data to relative porosity and permeability used Chillingarian approach and Baker-Hughes Atlas of log responses. Then boundary marker was drawn to separated different aquifer layers. Simple linear regression equations were derived from the transformation: (a) tuf layers: θ = -0.0023ρ + 2.5619, μ = -63.514θ + 167.38, σ = 22.912 μ + 238.78; (b) clay layers: θ = -0.0181 ρ + 2.6281, μ = -61.842 θ + 163.91, σ = 5.1202 μ - 11.503; (c) sand layers: θ = -0.0078 ρ + 2.5992, μ = -60.75 θ + 161.02, σ = 394.35 μ - 2156.8. Based on the new aquifer taxonomy, three hydro-stratigraphic units (HSU) and six sub HSU have been defined. UHs 1 is the top layer of the BSGB, located at elevation above 650 masl. It has three sub HSU that consists of tuf and sand. The permeability (K) values of this unit range from 0,0014 to 0.1 m per day. HSU-2 with two sub HSU consists of tuf and sand, located at elevation from 625 to 650 masl. This unit has K values from 0.1 to 6 m per day. HSU-3, which is located at elevation from 500 to 625 masl, has only one sub HSU. This unit consists of tuf, sand, and volcanic breccias, with K values from 0.3 to 7.1 m per day. This models, however, are still needed more test to new dataset.

  17. Evaluation of Non-Nuclear Techniques for Well Logging: Technology Evaluation

    Energy Technology Data Exchange (ETDEWEB)

    Bond, Leonard J.; Denslow, Kayte M.; Griffin, Jeffrey W.; Dale, Gregory E.; Harris, Robert V.; Moran, Traci L.; Sheen, David M.; Schenkel, Thomas

    2010-11-01

    This report presents an initial review of the state-of-the-art nuclear and non-nuclear well logging methods and seeks to understand the technical and economic issues if AmBe, and potentially other isotope sources, are reduced or even eliminated in the oil-field services industry. Prior to considering alternative logging technologies, there is a definite need to open up discussions with industry regarding the feasibility and acceptability of source replacement. Industry views appear to range from those who see AmBe as vital and irreplaceable to those who believe that, with research and investment, it may be possible to transition to electronic neutron sources and employ combinations of non-nuclear technologies to acquire the desired petro-physical parameters. In one sense, the simple answer to the question as to whether petro-physical parameters can be sensed with technologies other than AmBe is probably "Yes". The challenges come when attention turns to record interpretation. The many decades of existing records form a very valuable proprietary resource, and the interpretation of subtle features contained in these records are of significant value to the oil-gas exploration community to correctly characterize a well. The demonstration of equivalence and correspondence/correlation between established and any new sensing modality, and correlations with historic records is critical to ensuring accurate data interpretation. Establishing the technical basis for such a demonstration represents a significant effort.

  18. Study on the Horizontal-well Injection Profile Logging Interpretation Technology

    Science.gov (United States)

    Li, Qiang; Yao, Xugang; He, Xiaolu; Shen, Linshu; Xu, Qingying; Liu, Dongming; Liu, Hongsheng

    2007-06-01

    In order to get higher injection capacity and raise the coefficient of water driving waves and accelerate the speed of oil extraction. Changqing field carries on the development of horizontal-well infusion exploitation in the XXQ sandstone layer oil pool district. In compare with the traditional vertical-well affusion, the effect of comprehensive result of horizontal-well infusion exploitation will enhance as five times more as the current value. Because the flow of horizontal-well varies more in compare with the level-well, many horizontal-well logging data is hard to explain from the normal regulations, because the influence of the dynamic state of well hole and the size of it. Basing on the flow state of horizontal-well and the analysis of the layer of the low degree state and the annular flow and the turbulent flow, in order to get the parameters. To make attempt research to the quantitative interpretation of the horizontal-well.

  19. Evaluation of Reservoir Characteristics of Well Kot-Sarang-2, Potwar Plateau, Pakistan Using Geophysical Logs

    Directory of Open Access Journals (Sweden)

    Syed Waqas Haider

    2016-12-01

    Full Text Available Present study deals with reservoir characterization of Kot-Sarang-2 well, located in central part of Potwar plateau of Upper Indus Basin, District Chakwal. The geological structure of the Potwar Basin is the product of the Tertiary Himalayan orogeny, which resulted in the formation of complex fold and thrust belt in this region. In the present work, an attempt has been made to delineate zones having fair shows of hydrocarbons accumulation. In addition to this, estimation of reservoir properties and formation evaluation using wireline logs is also the foremost objective of this study. Based on the wireline logging results, three zones have been marked. Paleocene Lockhart Limestone (3967m to 4045m, Permian Wargal Limestone (4160m to 4245m and Permian Amb Formation (4246m to 4285m are possible reservoirs encountered. Physical properties i.e. total porosity (Øt, effective porosity (ØE, resistivity of water (Rw, saturation of water (Sw and saturation of hydrocarbons (Sh are calculated. For the calculation of saturation of water (Sw both Archie’s equation (Swa and Indonesian equation (Swi are applied. Results show that Amb and Wargal formations are showing fair to good saturation of Hydrocarbons (Sh i.e.73% and 88% respectively, but this is due to high resistivity values of these formations and porosity log also giving very low values. Effective porosity for zones Lockhart, Wargal and Amb are 2.56%, 3.5% and 1.32% respectively. Based on these results it is inferred that these formations have low potential for an economically feasible production of hydrocarbons.

  20. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-01-01

    of 15 major rock-forming minerals and porosities of 0–30 per cent. Petrophysical properties and their well-logging-tool-characteristic readings were assigned to these rock-forming minerals and to pore-filling fluids. Relationships are explored between each thermal property and other petrophysical...... of each property vary depending on the selected well-log combination. Best prediction is in the range of 2–8 per cent for the specific heat capacity, of 5–10 per cent for the thermal conductivity, and of 8–15 for the thermal diffusivity, respectively. Well-log derived thermal conductivity is validated...... by laboratory data measured on cores from deep boreholes of the Danish Basin, the North German Basin, and the Molasse Basin. Additional validation of thermal conductivity was performed by comparing predicted and measured temperature logs. The maximum deviation between these logs is

  1. Characterization of Rock Mechanical Properties Using Lab Tests and Numerical Interpretation Model of Well Logs

    Directory of Open Access Journals (Sweden)

    Hao Xu

    2016-01-01

    Full Text Available The tight gas reservoir in the fifth member of the Xujiahe formation contains heterogeneous interlayers of sandstone and shale that are low in both porosity and permeability. Elastic characteristics of sandstone and shale are analyzed in this study based on petrophysics tests. The tests indicate that sandstone and mudstone samples have different stress-strain relationships. The rock tends to exhibit elastic-plastic deformation. The compressive strength correlates with confinement pressure and elastic modulus. The results based on thin-bed log interpretation match dynamic Young’s modulus and Poisson’s ratio predicted by theory. The compressive strength is calculated from density, elastic impedance, and clay contents. The tensile strength is calibrated using compressive strength. Shear strength is calculated with an empirical formula. Finally, log interpretation of rock mechanical properties is performed on the fifth member of the Xujiahe formation. Natural fractures in downhole cores and rock microscopic failure in the samples in the cross section demonstrate that tensile fractures were primarily observed in sandstone, and shear fractures can be observed in both mudstone and sandstone. Based on different elasticity and plasticity of different rocks, as well as the characteristics of natural fractures, a fracture propagation model was built.

  2. Quantitative interpretation of materials from well logging of the Karabagly site

    Energy Technology Data Exchange (ETDEWEB)

    Mamedov, T.G.; Madatova, E.A.; Mamedova, K.D.; Polyakova, R.A.; Sattarova, S.A.

    1979-01-01

    A staged ranged quantitative interpretation of materials from geophysical well studies (GIS) was conducted for a series of productive objects of the Karabagly deposit. Initial processing of the GIS diagrams was conducted with identification of the true values of the initial geophysical parameters, the lithological splitting of the section with the isolation of collector strata and establishment of the nature of their saturation, the quantitative interpretation of the complex of the GIS with identification of the values of the capacitance parameters of the productive objects of the deposit such as the oil and gas saturation thickness, the collector porosity coefficient and the coefficient of the oil and gas saturation and the clay level. The layered clay level was determined through a method of resistances to PS according to gamma logging and micrologging. The rock porosity coefficient was found through calculation, from PS and from the zone of penetration of the drilling mud filtrate. The coefficient of the oil and gas saturation of the isolated oil and gas collectors was calculated from theoretical and empirical formulas. The results of induction, side and microlateral logging were also used for analyzing the GIS materials.

  3. Geothermal characteristics of deep wells using geophysical logs in Pohang area, Korea

    Science.gov (United States)

    LIM, W.; Hamm, S. Y.; Lee, C.; Song, Y.; Kim, H.

    2016-12-01

    Pohang area displays a larger potential of geothermal energy with the highest heat flow of 83 mWm-2 in South Korea. A geothermal binary power plant with a generation capacity of 1.5MW using enhanced geothermal system (EGS) is under construction in Pohang area and will be completed until 2017. This study aims to reveal geothermal characteristics of four wells (BH-1 to BH-4 wells) of 2,383 m in depth in Pohang area, using geophysical logs. The geology of the study area is composed of tertiary mudstone of 200 - 359.1 m, tuff of 73 - 240 m, sandstone/mudstone of 46 - 907 m, rhyolite of 259 - 375 m, and andesitic volcanic breccia of 834 m in thicknesses from the surface, with granodiorite at bottom. By the result of the study, temperature and maximum electrical conductivity (EC) are 69.5°C at 1,502.6 m and 1,162 μS/cm at BH-2 well, 44.4°C at 912.3 m and 1,105 μS/cm at BH-3 well, and 82.5°C at 1,981.3 m and 3,412 μS/cm at BH-4 well. Thermal conductivity values at saturated state are 2.14 - 3.95 W/m-K (average 3.47 W/m-K) at BH-1 well and 2.36 - 3.61 W/m-K (average 2.85 W/m-K) at BH-4 well. ß (determining heat flow rate and up/down direction) values were estimated by using 1-D steady-state heat transfer equation and were determined as -0.77 - 0.99 with the geothermal gradients (Ks) of 42.5 - 46.3°C/km at BH-1 well, -3.15 - 3.05 with the Ks of 25.0 - 29.1°C/km at BH-2, -1.80 - 2.09 with the Ks of 20.0 - 23.0°C/km at BH-3 well, and -4.10 - 5.18 with the Ks of 30.2 - 39.0°C/km at BH-4 well. Most depths of all the wells showed upward heat transfer. Based on the geophysical logs, the main aquifer is located between 200 and 300 meters. KEY WORDS: Geothermal gradient, thermal conductivity, geophysical logs, ß value, heat transfer equation, Pohang area Acknowledgement This work was supported by grants from the Principal Research Fund of Korea Institute of the Geoscience and Mineral Resources (KIGAM 16-3411).

  4. A Measuring System for Well Logging Attitude and a Method of Sensor Calibration

    Directory of Open Access Journals (Sweden)

    Yong Ren

    2014-05-01

    Full Text Available This paper proposes an approach for measuring the azimuth angle and tilt angle of underground drilling tools with a MEMS three-axis accelerometer and a three-axis fluxgate sensor. A mathematical model of well logging attitude angle is deduced based on combining space coordinate transformations and algebraic equations. In addition, a system implementation plan of the inclinometer is given in this paper, which features low cost, small volume and integration. Aiming at the sensor and assembly errors, this paper analyses the sources of errors, and establishes two mathematical models of errors and calculates related parameters to achieve sensor calibration. The results show that this scheme can obtain a stable and high precision azimuth angle and tilt angle of drilling tools, with the deviation of the former less than ±1.4° and the deviation of the latter less than ±0.1°.

  5. A measuring system for well logging attitude and a method of sensor calibration.

    Science.gov (United States)

    Ren, Yong; Wang, Yangdong; Wang, Mijian; Wu, Sheng; Wei, Biao

    2014-05-23

    This paper proposes an approach for measuring the azimuth angle and tilt angle of underground drilling tools with a MEMS three-axis accelerometer and a three-axis fluxgate sensor. A mathematical model of well logging attitude angle is deduced based on combining space coordinate transformations and algebraic equations. In addition, a system implementation plan of the inclinometer is given in this paper, which features low cost, small volume and integration. Aiming at the sensor and assembly errors, this paper analyses the sources of errors, and establishes two mathematical models of errors and calculates related parameters to achieve sensor calibration. The results show that this scheme can obtain a stable and high precision azimuth angle and tilt angle of drilling tools, with the deviation of the former less than ±1.4° and the deviation of the latter less than ±0.1°.

  6. Scientific Drilling of Impact Craters - Well Logging and Core Analyses Using Magnetic Methods (Invited)

    Science.gov (United States)

    Fucugauchi, J. U.; Perez-Cruz, L. L.; Velasco-Villarreal, M.

    2013-12-01

    Drilling projects of impact structures provide data on the structure and stratigraphy of target, impact and post-impact lithologies, providing insight on the impact dynamics and cratering. Studies have successfully included magnetic well logging and analyses in core and cuttings, directed to characterize the subsurface stratigraphy and structure at depth. There are 170-180 impact craters documented in the terrestrial record, which is a small proportion compared to expectations derived from what is observed on the Moon, Mars and other bodies of the solar system. Knowledge of the internal 3-D deep structure of craters, critical for understanding impacts and crater formation, can best be studied by geophysics and drilling. On Earth, few craters have yet been investigated by drilling. Craters have been drilled as part of industry surveys and/or academic projects, including notably Chicxulub, Sudbury, Ries, Vredefort, Manson and many other craters. As part of the Continental ICDP program, drilling projects have been conducted on the Chicxulub, Bosumtwi, Chesapeake, Ries and El gygytgyn craters. Inclusion of continuous core recovery expanded the range of paleomagnetic and rock magnetic applications, with direct core laboratory measurements, which are part of the tools available in the ocean and continental drilling programs. Drilling studies are here briefly reviewed, with emphasis on the Chicxulub crater formed by an asteroid impact 66 Ma ago at the Cretaceous/Paleogene boundary. Chicxulub crater has no surface expression, covered by a kilometer of Cenozoic sediments, thus making drilling an essential tool. As part of our studies we have drilled eleven wells with continuous core recovery. Magnetic susceptibility logging, magnetostratigraphic, rock magnetic and fabric studies have been carried out and results used for lateral correlation, dating, formation evaluation, azimuthal core orientation and physical property contrasts. Contributions of magnetic studies on impact

  7. Flow-Log Analysis for Hydraulic Characterization of Selected Test Wells at the Indian Point Energy Center, Buchanan, New York

    Science.gov (United States)

    Williams, John H.

    2008-01-01

    Flow logs from 24 test wells were analyzed as part of the hydraulic characterization of the metamorphosed and fractured carbonate bedrock at the Indian Point Energy Center in Buchanan, New York. The flow logs were analyzed along with caliper, optical- and acoustic-televiewer, and fluid-resistivity and temperature logs to determine the character and distribution of fracture-flow zones and estimate their transmissivities and hydraulic heads. Many flow zones were associated with subhorizontal to shallow-dipping fractured zones, southeast-dipping bedding fractures, northwest-dipping conjugate fractures, or combinations of bedding and conjugate fractures. Flow-log analysis generally provided reasonable first-order estimates of flow-zone transmissivity and head differences compared with the results of conventional hydraulic-test analysis and measurements. Selected results of an aquifer test and a tracer test provided corroborating information in support of the flow-log analysis.

  8. Novel methodology for accurate resolution of fluid signatures from multi-dimensional NMR well-logging measurements

    Science.gov (United States)

    Anand, Vivek

    2017-03-01

    A novel methodology for accurate fluid characterization from multi-dimensional nuclear magnetic resonance (NMR) well-logging measurements is introduced. This methodology overcomes a fundamental challenge of poor resolution of features in multi-dimensional NMR distributions due to low signal-to-noise ratio (SNR) of well-logging measurements. Based on an unsupervised machine-learning concept of blind source separation, the methodology resolves fluid responses from simultaneous analysis of large quantities of well-logging data. The multi-dimensional NMR distributions from a well log are arranged in a database matrix that is expressed as the product of two non-negative matrices. The first matrix contains the unique fluid signatures, and the second matrix contains the relative contributions of the signatures for each measurement sample. No a priori information or subjective assumptions about the underlying features in the data are required. Furthermore, the dimensionality of the data is reduced by several orders of magnitude, which greatly simplifies the visualization and interpretation of the fluid signatures. Compared to traditional methods of NMR fluid characterization which only use the information content of a single measurement, the new methodology uses the orders-of-magnitude higher information content of the entire well log. Simulations show that the methodology can resolve accurate fluid responses in challenging SNR conditions. The application of the methodology to well-logging data from a heavy oil reservoir shows that individual fluid signatures of heavy oil, water associated with clays and water in interstitial pores can be accurately obtained.

  9. Getting it straight : new production-logging tool for horizontal wells presents stiff competition for coiled tubing

    Energy Technology Data Exchange (ETDEWEB)

    Mahony, J.

    2009-05-15

    This article described a production logging system developed by Norway-based Ziebel AS. The new ZipLog production-logging tool for horizontal wells presents competition for coiled tubing. The article noted that the disadvantage of using coiled tubing is its tendency to resume downhole the curve it acquired on the spool, and a tendency to re-coil. Other issues regarding coiled tubing include weight and rigidity. The benefits of using ZipLog can be attributed to its carbon-epoxy construction. In particular, its lightweight, high strength and natural rigidity make the composite a natural for downhole use. The rod will also allow access to certain highly-deviated wells previously thought unloggable. Road-testing of tools were also presented. Differences related to mode of operation between coiled tubing and ZipLog's rod were also outlined. It was concluded that ZipLog could be used in production tubing, casings and in the open hole. Although the rod does not currently include any electrical cable, plans are underway to add one, enabling standard wireline logging to be added to the system's uses. In addition, the article noted that plans to introduce the system in Canada are under consideration. 1 ref., 3 figs.

  10. High-resolution well-log derived dielectric properties of gas-hydrate-bearing sediments, Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Sun, Y.; Goldberg, D.; Collett, T.; Hunter, R.

    2011-01-01

    A dielectric logging tool, electromagnetic propagation tool (EPT), was deployed in 2007 in the BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well (Mount Elbert Well), North Slope, Alaska. The measured dielectric properties in the Mount Elbert well, combined with density log measurements, result in a vertical high-resolution (cm-scale) estimate of gas hydrate saturation. Two hydrate-bearing sand reservoirs about 20 m thick were identified using the EPT log and exhibited gas-hydrate saturation estimates ranging from 45% to 85%. In hydrate-bearing zones where variation of hole size and oil-based mud invasion are minimal, EPT-based gas hydrate saturation estimates on average agree well with lower vertical resolution estimates from the nuclear magnetic resonance logs; however, saturation and porosity estimates based on EPT logs are not reliable in intervals with substantial variations in borehole diameter and oil-based invasion.EPT log interpretation reveals many thin-bedded layers at various depths, both above and below the thick continuous hydrate occurrences, which range from 30-cm to about 1-m thick. Such thin layers are not indicated in other well logs, or from the visual observation of core, with the exception of the image log recorded by the oil-base microimager. We also observe that EPT dielectric measurements can be used to accurately detect fine-scale changes in lithology and pore fluid properties of hydrate-bearing sediments where variation of hole size is minimal. EPT measurements may thus provide high-resolution in-situ hydrate saturation estimates for comparison and calibration with laboratory analysis. ?? 2010 Elsevier Ltd.

  11. Integrated reservoir characterization for unconventional reservoirs using seismic, microseismic and well log data

    Science.gov (United States)

    Maity, Debotyam

    This study is aimed at an improved understanding of unconventional reservoirs which include tight reservoirs (such as shale oil and gas plays), geothermal developments, etc. We provide a framework for improved fracture zone identification and mapping of the subsurface for a geothermal system by integrating data from different sources. The proposed ideas and methods were tested primarily on data obtained from North Brawley geothermal field and the Geysers geothermal field apart from synthetic datasets which were used to test new algorithms before actual application on the real datasets. The study has resulted in novel or improved algorithms for use at specific stages of data acquisition and analysis including improved phase detection technique for passive seismic (and teleseismic) data as well as optimization of passive seismic surveys for best possible processing results. The proposed workflow makes use of novel integration methods as a means of making best use of the available geophysical data for fracture characterization. The methodology incorporates soft computing tools such as hybrid neural networks (neuro-evolutionary algorithms) as well as geostatistical simulation techniques to improve the property estimates as well as overall characterization efficacy. The basic elements of the proposed characterization workflow involves using seismic and microseismic data to characterize structural and geomechanical features within the subsurface. We use passive seismic data to model geomechanical properties which are combined with other properties evaluated from seismic and well logs to derive both qualitative and quantitative fracture zone identifiers. The study has resulted in a broad framework highlighting a new technique for utilizing geophysical data (seismic and microseismic) for unconventional reservoir characterization. It provides an opportunity to optimally develop the resources in question by incorporating data from different sources and using their temporal

  12. New method for prediction of shale gas content in continental shale formation using well logs

    Science.gov (United States)

    Li, Sheng-Jie; Cui, Zhe; Jiang, Zhen-Xue; Shao, Yu; Liao, Wei; Li, Li

    2016-06-01

    Shale needs to contain a sufficient amount of gas to make it viable for exploitation. The continental heterogeneous shale formation in the Yan-chang (YC) area is investigated by firstly measuring the shale gas content in a laboratory and then investigating use of a theoretical prediction model. Key factors controlling the shale gas content are determined, and a prediction model for free gas content is established according to the equation of gas state and a new petrophysical volume model. Application of the Langmuir volume constant and pressure constant obtained from results of adsorption isotherms is found to be limited because these constants are greatly affected by experimental temperature and pressures. Therefore, using measurements of adsorption isotherms and thermodynamic theory, the influence of temperature, total organic carbon (TOC), and mineralogy on Langmuir volume constants and pressure constants are investigated in detail. A prediction model for the Langmuir pressure constant with a correction of temperatures is then established, and a prediction model for the Langmuir volume constant with correction of temperature, TOC, and quartz contents is also proposed. Using these corrected Langmuir constants, application of the Langmuir model determined using experimental adsorption isotherms is extrapolated to reservoir temperature, pressure, and lithological conditions, and a method for the prediction of shale gas content using well logs is established. Finally, this method is successfully applied to predict the shale gas content of the continental shale formation in the YC area, and practical application is shown to deliver good results with high precision.

  13. Identification and Evaluation of Low Resistivity Pay Zones by Well Logs and the Petrophysical Research in China

    Institute of Scientific and Technical Information of China (English)

    Mao Zhiqiang; Kuang Lichun; Xiao Chengwen; Li Guoxin; Zhou Cancan; Ouyang Jian

    2007-01-01

    This paper presents an overview of petrophysical research and exploration achievements of low resistivity pay (LRP) zone by well logs in China. It includes geological characteristics and characteristics of well log response of the low resistivity pay zones discovered and evaluated in recent years,as well as the problems in recognizing and evaluating low resistivity pay zones by well logs. The research areas mainly include the Neogene formations in the Bohai Bay Basin,the Triassic formations in the northern Tarim Basin and the Cretaceous formations in the Junggar Basin. The petrophysical research concerning recognition and evaluation of the low resistivity pays,based on their genetic types,is introduced in this paper.

  14. Permeability Estimation of Grosmont Formation, Alberta, Canada by Statistically Combining Well-logs and Core Measurements

    Science.gov (United States)

    Choi, J.; Keehm, Y.

    2011-12-01

    Permeability estimation in carbonate reservoirs is quite challenging since they are very heterogeneous. Moreover, the amount of core measurement data is commonly limited. In this paper, we present permeability maps for Grosmont formation in Canada with very limited permeability data, using bi-variated probability density function (porosity and permeability) conditioned to geological information. Grosmont formation consists of four units: Lower Grosmont (LG); Upper Grosmont (UG1); Upper Grosmont 2 (UG2); and Upper Grosmont 3 (UG3). From the previous studies, UG2 and UG3 are more promising reservoir units since they have larger porosity and permeability with vuggy pores and fractures by diagenesis (dolomitization and karstification). Thus, we applied our method to these two units. We first investigated core measurement data (porosity and permeability) and compared them to local geological aspects, such as the degree of diagenesis and vicinity of unconformity. Then we could divide the study area into 6 groups, and we established a bivariated probability density function (pdf) for each group and each unit (total of 12 pdfs) with core measurements of porosity and permeability. In the next step, we created porosity maps using well-log data for UG2 and UG3. The final step is to generate permeability maps for UG2 and UG3 by drawing a permeability value from the bivariated pdf conditioned to porosity. The final results show more realistic permeability maps for Grosmont formation when compared to conventional kriging results. Moreover, the strengths of this approach is (1) that it can use geological information and (2) that it can handle the variability of permeability, which can be naturally occurred in carbonate reservoirs. Acknowledgement: This work was supported by the Energy Resources R&D program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP) grant funded by the Korea government Ministry of Knowledge Economy (No. 2008RER11P0430302009).

  15. 浅析水平井测井解释技术%Logging interpretation for horizontal well

    Institute of Scientific and Technical Information of China (English)

    赵国柱; 刘静; 孙世民

    2015-01-01

    This article describes logging interpretation for horizontal well as well as with respect to its current development and issues in application.%本文针对水平井测井解释技术现状及存在的问题,对水平井测井解释技术进行了研究.

  16. Critical evaluation of the mechanical properties log (MPL) on a basal quartz well in the Caroline area

    Energy Technology Data Exchange (ETDEWEB)

    McLennan, J.D.; Elbel, J.; Mattheis, E.; Lindstrom, L.

    1982-01-01

    There is a need to quantify the in situ properties of barriers and pay zones in order to assess the potential for fracture containment and to optimize stimulation treatment design. A major testing program has been conducted jointly by Dome Petroleum Ltd., Dowell, and Schlumberger to compare laboratory-measured mechanical properties with those determined by well logging. The testing program was confined to the Basal Quartz Formation at a depth of ca 3,000 m, as it occurs in a Dome well in the Caroline area of Alberta. Laboratory testing included the determination of Young's modulus and Poisson's ratio at in situ temperature and stress conditions. The mechanical properties log was derived from the open-hole sonic log, and the in situ stresses were measured in the field. An attempt is made to explain the discrepancies on the basis of other known well data.

  17. Extrapolate well logs based on the constrained interpolation algorithm%基于约束插值算法的井资料外推

    Institute of Scientific and Technical Information of China (English)

    刘红伟; 刘洪; 秦月霜; 首皓

    2008-01-01

    Based on a detailed analysis of differences between seismic data and well logs, we discuss the problem of matching seismic traces and well logs and present a new matching method based on event search in instantaneous phase which greatly improves seismic resolution. The method is based on flattening events in instantaneous phase to compare the seismic traces to the well log traces with the same phase. We calculate the coefficients using the singular value decomposition method to extrapolate the well logs. As a result, the events in the seismic profile are continuous and match well with well logs. We apply this method to the Mao-2 well in Daqing Oilfield with good results.

  18. Novel methodology for accurate resolution of fluid signatures from multi-dimensional NMR well-logging measurements.

    Science.gov (United States)

    Anand, Vivek

    2017-03-01

    A novel methodology for accurate fluid characterization from multi-dimensional nuclear magnetic resonance (NMR) well-logging measurements is introduced. This methodology overcomes a fundamental challenge of poor resolution of features in multi-dimensional NMR distributions due to low signal-to-noise ratio (SNR) of well-logging measurements. Based on an unsupervised machine-learning concept of blind source separation, the methodology resolves fluid responses from simultaneous analysis of large quantities of well-logging data. The multi-dimensional NMR distributions from a well log are arranged in a database matrix that is expressed as the product of two non-negative matrices. The first matrix contains the unique fluid signatures, and the second matrix contains the relative contributions of the signatures for each measurement sample. No a priori information or subjective assumptions about the underlying features in the data are required. Furthermore, the dimensionality of the data is reduced by several orders of magnitude, which greatly simplifies the visualization and interpretation of the fluid signatures. Compared to traditional methods of NMR fluid characterization which only use the information content of a single measurement, the new methodology uses the orders-of-magnitude higher information content of the entire well log. Simulations show that the methodology can resolve accurate fluid responses in challenging SNR conditions. The application of the methodology to well-logging data from a heavy oil reservoir shows that individual fluid signatures of heavy oil, water associated with clays and water in interstitial pores can be accurately obtained. Copyright © 2017 Elsevier Inc. All rights reserved.

  19. Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs

    Science.gov (United States)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2015-12-01

    In this study, equations are developed that predict for synthetic sedimentary rocks (clastics, carbonates and evapourates) thermal properties comprising thermal conductivity, specific heat capacity and thermal diffusivity. The rock groups are composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities of 0-30 per cent. Petrophysical properties and their well-logging-tool-characteristic readings were assigned to these rock-forming minerals and to pore-filling fluids. Relationships are explored between each thermal property and other petrophysical properties (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) using multivariate statistics. The application of these relations allows computing continuous borehole profiles for each rock thermal property. The uncertainties in the prediction of each property vary depending on the selected well-log combination. Best prediction is in the range of 2-8 per cent for the specific heat capacity, of 5-10 per cent for the thermal conductivity, and of 8-15 for the thermal diffusivity, respectively. Well-log derived thermal conductivity is validated by laboratory data measured on cores from deep boreholes of the Danish Basin, the North German Basin, and the Molasse Basin. Additional validation of thermal conductivity was performed by comparing predicted and measured temperature logs. The maximum deviation between these logs is effect on the subsurface temperature field can be observed in the North German Basin. This effect reduces the surface heat-flow density by 25 mW m-2.

  20. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    capacity in sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities......: Fuchs, Sven; Balling, Niels; Förster, Andrea (2015): Calculation of thermal conductivity, thermal diffusivity and specific heat capacity of sedimentary rocks using petrophysical well logs. Geophysical Journal International 203, 1977-2000, doi: 10.1093/gji/ggv403...

  1. Differential interpretation of the results of well logging with scattered gamma radiation of radioactive ores

    Energy Technology Data Exchange (ETDEWEB)

    Davydov, Yu.B.; Kuzin, V.F.

    1979-01-01

    Studied are the possibilities of quantitative interpretation of the results of logging of scattered gamma radiation. Recording of the scattered gamma radiation of radioactive ores makes it possible in a number of cases to solve the questions of lithological separation of rocks and the identification of their substantive composition. The effectiveness of exploration of radioactive raw materials is increased.

  2. The thermal maturation degree of organic matter from source rocks revealed by wells logs including examples from Murzuk Basin, Libya

    Energy Technology Data Exchange (ETDEWEB)

    Negoita, V.; Gheorghe, A.

    1995-08-01

    The customary technique used to know the organic matter quantity per rock volume it as well as the organic matter maturation stage is based on geochemical analyses accomplished on a preselected number of samples and cuttings drawn from boreholes during the drilling period. But the same objectives can be approached without any extra cost using the continuous measurements of well logs recorded in each well from the ground surface to the total depth. During the diagenetic stage, the identification of potential source rocks out of which no hydrocarbon have been generated may be carried out using a well logging suite including Gamma Ray Spectrometry, the Compensated Neutron/Litho Density combination and a Dual Induction/Sonic Log. During the catagenetic stage the onset of oil generation brings some important changes in the organic matter structure as well as in the fluid distribution throughout the pore space of source rocks. The replacement of electric conductive water by electric non-conductive hydrocarbons, together with water and oil being expelled from source rocks represent a process of different intensities dependent of time/temperature geohistory and kerogen type. The different generation and expulsion scenarios of hydrocarbons taking place during the catagenetic and metagenetic stages of source rocks are very well revealed by Induction and Laterolog investigations. Several crossplots relating vitrinite reflectance, total organic carbon and log-derived physical parameters are illustrated and discussed. The field applications are coming from Murzuk Basin, where Rompetrol of Libya is operating.

  3. Machine learning with neural networks - a case study of estimating thermal conductivity with ancient well-log data

    Science.gov (United States)

    Harrison, Benjamin; Sandiford, Mike; McLaren, Sandra

    2016-04-01

    Supervised machine learning algorithms attempt to build a predictive model using empirical data. Their aim is to take a known set of input data along with known responses to the data, and adaptively train a model to generate predictions for new data inputs. A key attraction to their use is the ability to perform as function approximators where the definition of an explicit relationship between variables is infeasible. We present a novel means of estimating thermal conductivity using a supervised self-organising map algorithm, trained on about 150 thermal conductivity measurements, and using a suite of five electric logs common to 14 boreholes. A key motivation of the study was to supplement the small number of direct measurements of thermal conductivity with the decades of borehole data acquired in the Gippsland Basin to produce more confident calculations of surface heat flow. A previous attempt to generate estimates from well-log data in the Gippsland Basin using classic petrophysical log interpretation methods was able to produce reasonable synthetic thermal conductivity logs for only four boreholes. The current study has extended this to a further ten boreholes. Interesting outcomes from the study are: the method appears stable at very low sample sizes (< ~100); the SOM permits quantitative analysis of essentially qualitative uncalibrated well-log data; and the method's moderate success at prediction with minimal effort tuning the algorithm's parameters.

  4. Implementation of a tree algorithm in MCNP code for nuclear well logging applications

    Energy Technology Data Exchange (ETDEWEB)

    Li Fusheng, E-mail: fusheng.li@bakerhughes.com [Baker Hughes Incorporated, 2001 Rankin Rd. Houston, TX 77073-5101 (United States); Han Xiaogang [Baker Hughes Incorporated, 2001 Rankin Rd. Houston, TX 77073-5101 (United States)

    2012-07-15

    The goal of this paper is to develop some modeling capabilities that are missing in the current MCNP code. Those missing capabilities can greatly help for some certain nuclear tools designs, such as a nuclear lithology/mineralogy spectroscopy tool. The new capabilities to be developed in this paper include the following: zone tally, neutron interaction tally, gamma rays index tally and enhanced pulse-height tally. The patched MCNP code also can be used to compute neutron slowing-down length and thermal neutron diffusion length. - Highlights: Black-Right-Pointing-Pointer Tree structure programming is suitable for Monte-Carlo based particle tracking. Black-Right-Pointing-Pointer Enhanced pulse height tally is developed for oilwell logging tool simulation. Black-Right-Pointing-Pointer Neutron interaction tally and gamma ray index tally for geochemical logging.

  5. Pore structure effect on reservoir electrical properties and well logging evaluation

    Institute of Scientific and Technical Information of China (English)

    Bian Huan-Lin; Guan Ju; Mao Zhi-Qiang; Ju Xiao-Dong; Han Gui-Qing

    2014-01-01

    The reservoir pore structure controls the reservoir quality and resistivity response of hydrocarbon-bearing zones and thus, critically affects logging interpretation. We use petrophysical data in three types of reservoir with different pore structure characteristics to show that the complexity of pore structure had a significant effect on the effective porosity and permeability regardless of geological factors responsible for the formation of pore structure. Moreover,, the distribution and content of conductive fluids in the reservoir varies dramatically owing to pore structure differences, which also induces resistivity variations in reservoir rocks. Hence, the origin of low-resistivity hydrocarbon-bearing zones, except for those with conductive matrix and mud filtrate invasion, is attributed to the complexity of the pore structures. Consequently, reservoir-specific evaluation models, parameters, and criteria should be chosen for resistivity log interpretation to make a reliable evaluation of reservoir quality and fluids.

  6. Well log analysis to assist the interpretation of 3-D seismic data at Milne Point, north slope of Alaska

    Science.gov (United States)

    Lee, Myung W.

    2005-01-01

    In order to assess the resource potential of gas hydrate deposits in the North Slope of Alaska, 3-D seismic and well data at Milne Point were obtained from BP Exploration (Alaska), Inc. The well-log analysis has three primary purposes: (1) Estimate gas hydrate or gas saturations from the well logs; (2) predict P-wave velocity where there is no measured P-wave velocity in order to generate synthetic seismograms; and (3) edit P-wave velocities where degraded borehole conditions, such as washouts, affected the P-wave measurement significantly. Edited/predicted P-wave velocities were needed to map the gas-hydrate-bearing horizons in the complexly faulted upper part of 3-D seismic volume. The estimated gas-hydrate/gas saturations from the well logs were used to relate to seismic attributes in order to map regional distribution of gas hydrate inside the 3-D seismic grid. The P-wave velocities were predicted using the modified Biot-Gassmann theory, herein referred to as BGTL, with gas-hydrate saturations estimated from the resistivity logs, porosity, and clay volume content. The effect of gas on velocities was modeled using the classical Biot-Gassman theory (BGT) with parameters estimated from BGTL.

  7. Neural network prediction of carbonate lithofacies from well logs, Big Bow and Sand Arroyo Creek fields, Southwest Kansas

    Science.gov (United States)

    Qi, L.; Carr, T.R.

    2006-01-01

    In the Hugoton Embayment of southwestern Kansas, St. Louis Limestone reservoirs have relatively low recovery efficiencies, attributed to the heterogeneous nature of the oolitic deposits. This study establishes quantitative relationships between digital well logs and core description data, and applies these relationships in a probabilistic sense to predict lithofacies in 90 uncored wells across the Big Bow and Sand Arroyo Creek fields. In 10 wells, a single hidden-layer neural network based on digital well logs and core described lithofacies of the limestone depositional texture was used to train and establish a non-linear relationship between lithofacies assignments from detailed core descriptions and selected log curves. Neural network models were optimized by selecting six predictor variables and automated cross-validation with neural network parameters and then used to predict lithofacies on the whole data set of the 2023 half-foot intervals from the 10 cored wells with the selected network size of 35 and a damping parameter of 0.01. Predicted lithofacies results compared to actual lithofacies displays absolute accuracies of 70.37-90.82%. Incorporating adjoining lithofacies, within-one lithofacies improves accuracy slightly (93.72%). Digital logs from uncored wells were batch processed to predict lithofacies and probabilities related to each lithofacies at half-foot resolution corresponding to log units. The results were used to construct interpolated cross-sections and useful depositional patterns of St. Louis lithofacies were illustrated, e.g., the concentration of oolitic deposits (including lithofacies 5 and 6) along local highs and the relative dominance of quartz-rich carbonate grainstone (lithofacies 1) in the zones A and B of the St. Louis Limestone. Neural network techniques are applicable to other complex reservoirs, in which facies geometry and distribution are the key factors controlling heterogeneity and distribution of rock properties. Future work

  8. In-situ gas hydrate hydrate saturation estimated from various well logs at the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    Science.gov (United States)

    Lee, M.W.; Collett, T.S.

    2011-01-01

    In 2006, the U.S. Geological Survey (USGS) completed detailed analysis and interpretation of available 2-D and 3-D seismic data and proposed a viable method for identifying sub-permafrost gas hydrate prospects within the gas hydrate stability zone in the Milne Point area of northern Alaska. To validate the predictions of the USGS and to acquire critical reservoir data needed to develop a long-term production testing program, a well was drilled at the Mount Elbert prospect in February, 2007. Numerous well log data and cores were acquired to estimate in-situ gas hydrate saturations and reservoir properties.Gas hydrate saturations were estimated from various well logs such as nuclear magnetic resonance (NMR), P- and S-wave velocity, and electrical resistivity logs along with pore-water salinity. Gas hydrate saturations from the NMR log agree well with those estimated from P- and S-wave velocity data. Because of the low salinity of the connate water and the low formation temperature, the resistivity of connate water is comparable to that of shale. Therefore, the effect of clay should be accounted for to accurately estimate gas hydrate saturations from the resistivity data. Two highly gas hydrate-saturated intervals are identified - an upper ???43 ft zone with an average gas hydrate saturation of 54% and a lower ???53 ft zone with an average gas hydrate saturation of 50%; both zones reach a maximum of about 75% saturation. ?? 2009.

  9. Integrated interpretation of a geological structure based on the combination of well logging, VSP and seismic methods

    Energy Technology Data Exchange (ETDEWEB)

    Wachi, Noboru; Asakura, Natsuo; Ota, Yoichi; Ikawa, Takeshi; Iwaki, Yumio

    1985-03-15

    An integrated analysis procedure is given for a reliable interpretation of geological structure using the combination of well log, VSP (Vertical Seismic Profiling) and seismic records. Survey records are analyzed for 4 distinct high porosity layers following the procedure. The VSP records contained information about various effects caused by the characteristics of the layers, and the wave forms resembled more closely to the records obtained by seismic methods. The synthetic seismogram of VSP showed a better agreement with the seismic record than that of sonic log, and VSP method was confirmed to be effective for a reliable structure interpretation of oil and gas layers. Also, long spacing sonic log analysis showed a significant attenuations of elastic waves corresponding to high porosity layers. (19 figs, 7 refs)

  10. Application of Attribute Reduction to Well Logging%属性约简在石油测井中的应用研究

    Institute of Scientific and Technical Information of China (English)

    李昌彪; 宋建平; 夏克文

    2005-01-01

    The quantity of well logging data is increasing exponentially, hence methods of extracting the useful information or attribution from the logging database are becoming very important in logging interpretation. So, the method of logging attribute reduction is presented based on a rough set, i.e., first determining the core of the information table, then calculating the significance of each attribute, and finally obtaining the relative reduction table. The application result shows that the method of attribute reduction is feasible and can be used for optimizing logging attributes, and decreasing redundant logging information to a great extent.

  11. Modelling discontinuous well log signal to identify lithological boundaries via wavelet analysis: An example from KTB borehole data

    Indian Academy of Sciences (India)

    Amrita Singh; Saumen Maiti; R K Tiwar

    2016-06-01

    Identification of sharp and discontinuous lithological boundaries from well log signal stemming fromheterogeneous subsurface structures assumes a special significance in geo-exploration studies. Well logdata acquired from various geological settings generally display nonstationary/nonlinear characteristicswith varying wavelengths and frequencies. Modelling of such complex well-log signals using the conventionalsignal processing techniques either fails to catch-up abrupt boundaries or at the best, do notprovide precise information on insidious lithological discontinuities. In this paper, we have proposed anew wavelet transform-based algorithm to model the abrupt discontinuous changes from well log databy taking care of nonstationary characteristics of the signal. Prior to applying the algorithm on thegeophysical well data, we analyzed the distribution of wavelet coefficients using synthetic signal generatedby the first order nonstationary auto-regressive model and then applied the method on actual welllog dataset obtained from the KTB bore hole, Germany. Besides identifying the formation of layeredboundaries, the underlying method also maps some additional formation boundaries, which were hithertoundetected at the KTB site. The results match well with known geological lithostratigraphy andwill be useful for constraining the future model of KTB bore hole data.

  12. Drilling and geophysical logs of the tophole at an oil-and-gas well site, Central Venango County, Pennsylvania

    Science.gov (United States)

    Williams, John H.; Bird, Philip H.; Conger, Randall W.; Anderson, J. Alton

    2014-01-01

    In a study conducted by the U.S. Geological Survey, in cooperation with the Pennsylvania Department of Conservation and Natural Resources, Bureau of Topographic and Geologic Survey, drilling and geophysical logs were used to characterize the geohydrologic framework and the freshwater and saline-water zones penetrated by the tophole at an oil-and-gas well site in central Venango County, Pennsylvania. The geohydrologic setting of the well site is typical of the dissected Appalachian Plateau underlain by Pennsylvanian and Mississippian sandstone and shale. The drilling, gamma, and acoustic-televiewer logs collected from the 575-foot deep tophole define the penetrated Pennsylvanian and Mississippian stratigraphic units and their lithology. The caliper, video, and acoustic-televiewer logs delineate multiple bedding-related and high-angle fractures in the lower Pottsville Group and Shenango Formation from 22 to 249 feet below land surface. The caliper and acoustic-televiewer logs indicate a sparsity of fractures below 249 feet below land surface in the lowermost Shenango Formation, Cuyahoga Group, Corry Sandstone, “Drake Well” formation, and upper Riceville Formation.

  13. An Amplitude-normalized Pseudo Well-log Construction Method and its Application on AVO Inversion in a Well-absent Marine Area

    Directory of Open Access Journals (Sweden)

    Fan Chunyan

    2015-06-01

    Full Text Available AVO inversion is hard to be efficiently applied in unexploited fields due to the insufficiency of well information. For the sake of AVO inversion in a well-absent area, the most conventional method is to construct pseudo well-logs by defining seismic processing velocity as the P-velocity and computing S-velocity and density using empirical formulas, yet the resolution of the corresponding earth models and final inverted results could be extremely low, and a rough formula could destroy the inversion thoroughly. To overcome this problem, an amplitudenormalized pseudo well-log construction method that reconstructs pseudo well-logs in accordance with computed P-wave reflection amplitudes and nearby drilling data is proposed in this paper. It enhances the inversion resolution efficiently with respect to the real elastic parameter relationships, so that the corresponding AVO inversion results are reasonably improved. In summary, the proposed method is successfully applied in the AVO inversion of a well-absent marine area, and could be valuable in the early phase, particularly of the offshore hydrocarbon exploration.

  14. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    DEFF Research Database (Denmark)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    Numerical temperature models generated for geodynamic studies as well as for geothermal energy solutions heavily depend on rock thermal properties. Best practice for the determination of those parameters is the measurement of rock samples in the laboratory. Given the necessity to enlarge databases...... capacity in sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities......, hydrogen index, volume fraction of shale and photoelectric absorption index) on a regression sub set of data (70% of data) (Fuchs et al., 2015). Prediction quality was quantified on the remaining test sub set (30% of data). The combination of three to five well-log parameters results in predictions...

  15. A Generalized Approach for the Interpretation of Geophysical Well Logs in Ground-Water Studies - Theory and Application

    Science.gov (United States)

    Paillet, Frederick L.; Crowder, R.E.

    1996-01-01

    Quantitative analysis of geophysical logs in ground-water studies often involves at least as broad a range of applications and variation in lithology as is typically encountered in petroleum exploration, making such logs difficult to calibrate and complicating inversion problem formulation. At the same time, data inversion and analysis depend on inversion model formulation and refinement, so that log interpretation cannot be deferred to a geophysical log specialist unless active involvement with interpretation can be maintained by such an expert over the lifetime of the project. We propose a generalized log-interpretation procedure designed to guide hydrogeologists in the interpretation of geophysical logs, and in the integration of log data into ground-water models that may be systematically refined and improved in an iterative way. The procedure is designed to maximize the effective use of three primary contributions from geophysical logs: (1) The continuous depth scale of the measurements along the well bore; (2) The in situ measurement of lithologic properties and the correlation with hydraulic properties of the formations over a finite sample volume; and (3) Multiple independent measurements that can potentially be inverted for multiple physical or hydraulic properties of interest. The approach is formulated in the context of geophysical inversion theory, and is designed to be interfaced with surface geophysical soundings and conventional hydraulic testing. The step-by-step procedures given in our generalized interpretation and inversion technique are based on both qualitative analysis designed to assist formulation of the interpretation model, and quantitative analysis used to assign numerical values to model parameters. The approach bases a decision as to whether quantitative inversion is statistically warranted by formulating an over-determined inversion. If no such inversion is consistent with the inversion model, quantitative inversion is judged not

  16. New approaches in the indirect quantification of thermal rock properties in sedimentary basins: the well-log perspective

    Science.gov (United States)

    Fuchs, Sven; Balling, Niels; Förster, Andrea

    2016-04-01

    Numerical temperature models generated for geodynamic studies as well as for geothermal energy solutions heavily depend on rock thermal properties. Best practice for the determination of those parameters is the measurement of rock samples in the laboratory. Given the necessity to enlarge databases of subsurface rock parameters beyond drill core measurements an approach for the indirect determination of these parameters is developed, for rocks as well a for geological formations. We present new and universally applicable prediction equations for thermal conductivity, thermal diffusivity and specific heat capacity in sedimentary rocks derived from data provided by standard geophysical well logs. The approach is based on a data set of synthetic sedimentary rocks (clastic rocks, carbonates and evaporates) composed of mineral assemblages with variable contents of 15 major rock-forming minerals and porosities varying between 0 and 30%. Petrophysical properties are assigned to both the rock-forming minerals and the pore-filling fluids. Using multivariate statistics, relationships then were explored between each thermal property and well-logged petrophysical parameters (density, sonic interval transit time, hydrogen index, volume fraction of shale and photoelectric absorption index) on a regression sub set of data (70% of data) (Fuchs et al., 2015). Prediction quality was quantified on the remaining test sub set (30% of data). The combination of three to five well-log parameters results in predictions on the order of Journal International 203, 1977-2000, doi: 10.1093/gji/ggv403

  17. Acousto-electric well logging by eccentric source and extraction of shear wave

    Institute of Scientific and Technical Information of China (English)

    Cui Zhi-Wen; Wang Ke-Xie; Hu Heng-shan; Sun Jian-Guo

    2007-01-01

    The nonaxisymmetric acousto-electric field excited by an eccentric acoustic source in the borehole based on Pride seismoelectric theory is considered.It is shown that the acoustic field inside the borehole,converted electric and magnetic fields and coupled fields outside the borehole are composed of an infinitude of multipole fields with different orders.The numerical results show that both the electromagnetic waves and the seismoelectric field in the borehole.and the three components of both electric field and magnetic field can be detected.Measurements on the borehole axis will be of advantage to determining shear velocity information.The components of the symmetric and nonsymmetric acoustic and electromagnetic fields can be strengthened or weakened by adding or subtracting the two full waveforms logged in some azimuths.It may be a new method of directly measuring the shear wave velocity by using the borehole seismoelectric effect.

  18. Application of a Method for Calculating the Organic Carbon Content by Well Logs to Faulted Basins

    Institute of Scientific and Technical Information of China (English)

    SunJianping; LiuLuofu; PangXiongqi; GongGuangsheng; LiFengjun

    2005-01-01

    The source rock model used in this project was developed by French Petroleum Research Institute. The total organic carbon content was estimated primarily and directly by using continuous conventional logging curves (such as sonic and resistivity curves), which are calibrated through the laboratory analysis data of organic carbon of cores, cuttings or sidewall cores. Regional evaluations have been carried out in downwarping basins abroad. The Haila'er Basin is a faulted basin and the evaluation of such a basin is a new subject. On the basis of a regional evaluation method for the downwarping basins, a new method suitable to faulted basins was developed. The effect is satisfactory when this new method is applied to the Wu'erxun Sag and the Bei'er Sag.

  19. 测井资料在试井中的应用%Application of Logging Information in Well Testing

    Institute of Scientific and Technical Information of China (English)

    张金柱

    2015-01-01

    综合利用测井曲线和测井解释结果来确定测试目的层位,认识储层特征,为试井设计和解释提供有效厚度、渗透率、孔隙度、含水饱和度等基础输入参数,为测试方案编制、试井解释方法和解释模型的选择提供重要参考。正确利用测井资料获得试井所需要的参数是保证测试成功、资料完整、减少试井拟合工作量、提高解释结果可靠性的关键。%The paper aims to provide basic input parameters for well testing design and interpretation in regard to aspects such as effective thickness, permeability, porosity and water saturation and important reference for testing plan compilation and the selection of testing interpretation methods and interpretation models by comprehensively using log presentations and well log interpretations to determine the positions to be tested and understand the reservoir layer characteristics. Properly use logging information to obtain the parameters needed by well testing is the key to ensure successful tests and complete date, reduce well-testing fitting workload and enhance interpretation results reliability.

  20. Well log and 2D seismic data character of the Wilcox Group in south-central Louisiana

    Science.gov (United States)

    Enomoto, Catherine B.

    2014-01-01

    Well logs and 2D seismic data were used to interpret the depth and morphology of potential Paleocene and lower Eocene Wilcox Group slope and basin-floor reservoirs in south-central Louisiana. These may occur in a poorly explored area previously estimated by the U.S. Geological Survey to contain a mean undiscovered conventional resource potential of 26,398 billion cubic feet of gas and 423 million barrels of natural gas liquids.

  1. Reservoir characterization using core, well log, and seismic data and intelligent software

    Science.gov (United States)

    Soto Becerra, Rodolfo

    We have developed intelligent software, Oilfield Intelligence (OI), as an engineering tool to improve the characterization of oil and gas reservoirs. OI integrates neural networks and multivariate statistical analysis. It is composed of five main subsystems: data input, preprocessing, architecture design, graphics design, and inference engine modules. More than 1,200 lines of programming code as M-files using the language MATLAB been written. The degree of success of many oil and gas drilling, completion, and production activities depends upon the accuracy of the models used in a reservoir description. Neural networks have been applied for identification of nonlinear systems in almost all scientific fields of humankind. Solving reservoir characterization problems is no exception. Neural networks have a number of attractive features that can help to extract and recognize underlying patterns, structures, and relationships among data. However, before developing a neural network model, we must solve the problem of dimensionality such as determining dominant and irrelevant variables. We can apply principal components and factor analysis to reduce the dimensionality and help the neural networks formulate more realistic models. We validated OI by obtaining confident models in three different oil field problems: (1) A neural network in-situ stress model using lithology and gamma ray logs for the Travis Peak formation of east Texas, (2) A neural network permeability model using porosity and gamma ray and a neural network pseudo-gamma ray log model using 3D seismic attributes for the reservoir VLE 196 Lamar field located in Block V of south-central Lake Maracaibo (Venezuela), and (3) Neural network primary ultimate oil recovery (PRUR), initial waterflooding ultimate oil recovery (IWUR), and infill drilling ultimate oil recovery (IDUR) models using reservoir parameters for San Andres and Clearfork carbonate formations in west Texas. In all cases, we compared the results from

  2. Associating fuzzy logic, neural networks and multivariable statistic methodologies in the automatic identification of oil reservoir lithologies through well logs

    Energy Technology Data Exchange (ETDEWEB)

    Carrasquilla, Abel [Universidade Estadual do Norte Fluminense Darcy Ribeiro (UENF), Macae, RJ (Brazil). Lab. de Engenharia e Exploracao de Petroleo]. E-mail: abel@lenep.uenf.br; Silva, Jadir da [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Dept. de Geologia; Flexa, Roosevelt [Baker Hughes do Brasil Ltda, Macae, RJ (Brazil)

    2008-07-01

    In this article, we present a new approach to the automatic identification of lithologies using only well log data, which associates fuzzy logic, neural networks and multivariable statistic methods. Firstly, we chose well log data that represents lithological types, as gamma rays (GR) and density (RHOB), and, immediately, we applied a fuzzy logic algorithm to determine optimal number of clusters. In the following step, a competitive neural network is developed, based on Kohonen's learning rule, where the input layer is composed of two neurons, which represent the same number of used logs. On the other hand, the competitive layer is composed by several neurons, which have the same number of clusters as determined by the fuzzy logic algorithm. Finally, some data bank elements of the lithological types are selected at random to be the discriminate variables, which correspond to the input data of the multigroup discriminate analysis program. In this form, with the application of this methodology, the lithological types were automatically identified throughout the a well of the Namorado Oil Field, Campos Basin, which presented some difficulty in the results, mainly because of geological complexity of this field. (author)

  3. A method for correcting log-derived temperatures in deep wells, calibrated in the Gulf of Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Waples, D.W.; Pacheco, J.; Vera, A. [Pemex Exploracion y Produccion, Ciudad del Carmen, Campeche (Mexico)

    2004-07-01

    A method for correcting log-derived temperatures In deep wells (3500-6500 m) has been developed by comparing log temperatures from the Gulf of Campeche (Mexican Gulf of Mexico) with DST temperatures in the same wells. The equations developed in this study are modified slightly from those of Waples and Mahadir Ramly (2001), which were calibrated using data from depths <3500 m in Malaysia. The correction depends strongly on time since end of mud circulation (TSC) and, to a much lesser degree, on depth. In this study the true subsurface temperature (Celsius) is given by Ttrue Tsurf +f. }Tmeas-Tsurf 0.001391 }Z-4498 where f=1.32866{sup -0.005289TSC}, Tsurf is the seafloor or land-surface temperature ({sup o}C), Tmeas is the measured log temperature ({sup o}C), TSC is in hours and Z is depth below seafloor in metres. If TSC is unknown, it can be estimated from the trend of TSC with depth. (author)

  4. Characterization of injection wells in a fractured reservoir using PTS logs, Steamboat Hills Geothermal Field, Nevada, USA

    Energy Technology Data Exchange (ETDEWEB)

    Goranson, Colin; Combs, Jim

    1995-01-26

    The Steamboat Hills Geothermal Field in northwestern Nevada, about 15 km south of Reno, is a shallow (150m to 825m) moderate temperature (155 C to 168 C) liquid-dominated geothermal reservoir situated in highly-fractured granodiorite. Three injection wells were drilled and completed in granodiorite to dispose of spent geothermal fluids from the Steamboat II and III power plants (a 30 MW air-cooled binary-type facility). Injection wells were targeted to depths below 300m to inject spent fluids below producing fractures. First, quasi-static downhole pressure-temperature-spinner (PTS) logs were obtained. Then, the three wells were injection-tested using fluids between 80 C and 106 C at rates from 70 kg/s to 200 kg/s. PTS logs were run both up and down the wells during these injection tests. These PTS surveys have delineated the subsurface fracture zones which will accept fluid. The relative injectivity of the wells was also established. Shut-in interzonal flow within the wells was identified and characterized.

  5. Gamma well-logging in the Old Burial Ground of the Savannah River Site

    Energy Technology Data Exchange (ETDEWEB)

    Winn, W. G. [Westinghouse Savannah River Co., Aiken, SC (United States); Hofstetter, K. J. [Westinghouse Savannah River Co., Aiken, SC (United States); MacMurdo, K. W. [Westinghouse Savannah River Co., Aiken, SC (United States); Johnson, R. W. [Westinghouse Savannah River Co., Aiken, SC (United States); Matthews, W. B. [Westinghouse Savannah River Co., Aiken, SC (United States); Diamond, W. D. [Westinghouse Savannah River Co., Aiken, SC (United States); Moore, F. S. [Westinghouse Savannah River Co., Aiken, SC (United States); Hall, G. [Westinghouse Savannah River Co., Aiken, SC (United States); Maus, R. J. [Westinghouse Savannah River Co., Aiken, SC (United States); Walker, V. W. [Westinghouse Savannah River Co., Aiken, SC (United States); Sigg, R. A. [Westinghouse Savannah River Co., Aiken, SC (United States); Sanders, M. A. [Westinghouse Savannah River Co., Aiken, SC (United States)

    1995-01-01

    Results are given sequentially by well in the appendix; total is 44 wells. Overall, the 1994 results do not suggest that any significant changes in activity or location have occurred since the 1980 measurements. Depths and magnitudes of plume activities for 1980 and 1994 are compared.

  6. Measurement results of BHTV logging at the geothermal well. 1; Chinetsusei ni okeru BHTV kenso no sokutei kekka. 1

    Energy Technology Data Exchange (ETDEWEB)

    Lin, S. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan); Nakanishi, S.; Shimizu, I. [Electric Power Development Co. Ltd., Tokyo (Japan)

    1997-05-27

    In association with excavation of the No. 135 steam producing well in the Onikubi geothermal power plant in Miyagi Prefecture, shapes of production zones and drilling-induced fracture (DIF) were acquired from the borehole televiewer (BHTV) data. The BHTV logging shoots sound waves onto well walls of wells filled with fluid and detects the reflection waves to investigate the state of the well walls. Vertical fracture with opening lengths from 2 to 3 m were found at depths of about 1232 m and 1312 m. Water run-off has occurred at a depth of about 1312 m during the excavation, to which these vertical fractures might have contributed possibly. In depths of about 1232 m and 1312 m, fractures inclining toward north-east direction and south-west direction are predominant. Some fractures in the depth of about 1333 m incline toward east-south-east direction and west-north-west direction. Fracture inclination azimuth in all of the present logging sections is predominantly in north-east direction and south-west direction. When the DIF is considered to show the maximum compression azimuth, the earth`s crust stress azimuth is generally in east-west direction, which crosses slightly obliquely with the running direction of the predominant fracture in this well. 1 ref., 7 figs.

  7. Fractal theory modeling for interpreting nuclear and electrical well logging data and establishing lithological cross section in basaltic environment (case study from Southern Syria).

    Science.gov (United States)

    Asfahani, Jamal

    2017-05-01

    Fractal theory modeling technique is newly proposed in this research for interpreting the combination of nuclear well logging, including natural gamma ray, density and neutron-porosity, and the electrical well logging of long and short normal, for establishing the lithological cross section in basaltic environments. The logging data of Kodana well, localized in Southern Syria are used for testing and applying the proposed technique. The established cross section clearly shows the distribution and the identification of four kinds of basalt which are hard massive basalt, hard basalt, pyroclastic basalt and the alteration basalt products, clay. The concentration- Number (C-N) fractal modeling technique is successfully applied on the Kodana well logging data in southern Syria, and can be used efficiently when several wells with much well logging data with a high number of variables are required to be interpreted.

  8. Geophysical log analysis of selected test and residential wells at the Shenandoah Road National Superfund Site, East Fishkill, Dutchess County, New York

    Science.gov (United States)

    Reynolds, Richard J.; Anderson, J. Alton; Williams, John H.

    2015-01-01

    The U.S. Geological Survey collected and analyzed geophysical logs from 20 test wells and 23 residential wells at the Shenandoah Road National Superfund Site in East Fishkill, New York, from 2006 through 2010 as part of an Interagency Agreement to provide hydrogeologic technical support to the U.S. Environmental Protection Agency, Region 2. The geophysical logs collected include caliper, gamma, acoustic and optical televiewer, deviation, electromagnetic-induction, magnetic-susceptibility, fluid-property, and flow under ambient and pumped conditions. The geophysical logs were analyzed along with single-well aquifer test data and drilling logs to characterize the lithology, fabric, fractures, and flow zones penetrated by the wells. The results of the geophysical log analysis were used as part of the hydrogeologic characterization of the site and in the design of discrete-zone monitoring installations in the test wells and selected residential wells.

  9. Comprehensive Interpretation of Common Well Loggings%常规测井资料的综合解释研究

    Institute of Scientific and Technical Information of China (English)

    韩乾凤; 施泽进; 苟迎春; 陈涛

    2011-01-01

    With the development of oil exploration,there appear more and more complex condition of reservoir and oil-water system, which make the interpretation of well logging data more difficult. The paper analyzes the influence of reservoir characteristics,fluid parameters and engineering parameters on logging. On this basis,this paper introduces a method of key well,which applies 9 common well-loggings with other data to analyze oil-water distribution so that results are more reasonable with high accuracy. The example of X oil field suggests the availability of this method.%随着油田的不断勘探开发,有利储层的地质情况和油、气、水的分布越来越复杂,致使利用常规测井资料进行解释分析的难度加大.在分析储层特征、流体参数及工程参数等对测井相应影响的基础上,提出了运用关键井研究技术,采取常规测井资料结合地质、录井、生产动态等资料的综合判识方法,提高解释结果精度,并以某油气田为例进行效果分析,证明了该方法的有效性.

  10. The evaluation and interpretation of logging in Honghe oilfield horizontal well logging difference analysis%红河油田水平井测井评价与录井解释差异性分析

    Institute of Scientific and Technical Information of China (English)

    高勃胤

    2015-01-01

    Paper mainly discusses the characteristics and influence factor analysis of Honghe oilfield horizontal well comprehensive mud logging and well logging parameters and the integrated interpretation analysis.%文主要阐述了红河油田水平井综合录井与测井参数的特征和影响因素分析以及相关的综合解释分析.

  11. Seismic and well logging interpretation for evaluation of the lower Bahariya reservoir, southwest Qarun (SWQ) Field, Gindi Basin, Egypt

    Science.gov (United States)

    Sarhan, Mohammad Abdelfattah; Basal, A. M. K.; Ibrahim, Ibrahim Mohamed

    2017-09-01

    This paper focuses on seismic and well log interpretations for evaluating the sandstones of the Cenomanian Bahariya Formation in the southwest Qarun Field, Gindi Basin, northern Western Desert of Egypt. The seismic profiles display a clear anticlinal structure intersected by reverse faults in the study area. This faulted anticline has been interpreted to be one of the Syrian arc system folds formed by Upper Cretaceous tectonic inversion, which resulted from the NW movement of the African Plate relative to Laurasia. This anticline has been recommended as a target for exploration by the present work as it may represent a structural trap for hydrocarbon accumulation. The sandstones of the Lower Bahariya Formation in the southwest Qarun Field display good reservoir characteristics. The interpretation of the available well log data for the SWQ-21 and SWQ-25 wells for the Lower Bahariya Formation reflects a good reservoir quality for oil production in its topmost part. This reservoir possesses low SW (<50%), high porosity (16%), low SW/SXO and low BVW (<0.09) which all reflect a high potential for oil production.

  12. Fuzzy Logic Determination of Lithologies from Well Log Data: Application to the KTB Project Data set (Germany)

    Science.gov (United States)

    Bosch, David; Ledo, Juanjo; Queralt, Pilar

    2013-07-01

    Fuzzy logic has been used for lithology prediction with remarkable success. Several techniques such as fuzzy clustering or linguistic reasoning have proven to be useful for lithofacies determination. In this paper, a fuzzy inference methodology has been implemented as a MATLAB routine and applied for the first time to well log data from the German Continental Deep Drilling Program (KTB). The training of the fuzzy inference system is based on the analysis of the multi-class Matthews correlation coefficient computed for the classification matrix. For this particular data set, we have found that the best suited membership function type is the piecewise linear interpolation of the normalized histograms; that the best combination operator for obtaining the final lithology degrees of membership is the fuzzy gamma operator; and that all the available properties are relevant in the classification process. Results show that this fuzzy logic-based method is suited for rapidly and reasonably suggesting a lithology column from well log data, neatly identifying the main units and in some cases refining the classification, which can lead to a better interpretation. We have tested the trained system with synthetic data generated from property value distributions of the training data set to find that the differences in data distributions between both wells are significant enough to misdirect the inference process. However, a cross-validation analysis has revealed that, even with differences between data distributions and missing lithologies in the training data set, this fuzzy logic inference system is able to output a coherent classification.

  13. Radioprotection guidelines to the elaboration of a specific standard for the licensing of radioactive facilities on the practice of oil and gas well logging

    Energy Technology Data Exchange (ETDEWEB)

    Gomes, Rogerio dos Santos; Gomes, Joana D' Arc Ramos Lopes; Costa, Mara Lucia de Lara, E-mail: rogeriog@cnen.gov.br, E-mail: jlopes@cnen.gov.br, E-mail: mara@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN), Rio de Janeiro, RJ (Brazil); Miranda, Marcia Valeria F.E. Sa, E-mail: mvaleria@cnen.gov.br [Centro Regional de Ciencias Nucleares (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2011-07-01

    The regulatory process in oil and gas well logging has shown the need for specific standard for the issuance of a license authorizing the use of sealed sources in well logging activities, in order to guarantee the quality of many factors from the point of view of radiation protection. Currently, have been used only generic radiation protection standards, but are not comprehensive or technically suitable for a well logging licensing purpose. The lack of a specific standard for licensing in radioactive well logging operations in Brazil, weakens the nuclear regulatory body in your aim of regulate and licensing the activity. This work establish, as main objective, a guideline for the future Brazilian radioprotection code in well logging operations, presenting relevant aspects not covered by genetic radiation protection standards. (author)

  14. Numerical Simulation Characteristics of Logging Response in Water Injection Well by Reproducing Kernel Method

    Directory of Open Access Journals (Sweden)

    Ming-Jing Du

    2015-01-01

    Full Text Available Reproducing kernel Hilbert space method (RKHSM is an effective method. This paper, for the first time, uses the traditional RKHSM for solving the temperature field in two phase flows of multilayer water injection well. According to 2D oil-water temperature field mathematical model of two phase flows in cylindrical coordinates, selecting the properly initial and boundary conditions, by the process of Gram-Schmidt orthogonalization, the analytical solution was given by reproducing kernel functions in a series expansion form, and the approximate solution was expressed by n-term summation. The satisfied numerical results were carried out by Mathematica 7.0, showing that the larger the difference between injected water temperature and initial borehole temperature or water injection conditions, the more obvious the indication of water accepting zones. The numerical examples evidence the feasibility and effectiveness of the proposed method of the two phase flows in engineering.

  15. PREDICTING METHOD OF THE WELLBORE STABILITY OF INCLINED WELL BY WELL LOGGING%斜井井壁稳定的测井预测方法

    Institute of Scientific and Technical Information of China (English)

    陈科贵; 夏亚良; 高成军; 张歧安

    2011-01-01

    从影响井壁稳定的力学因素出发,通过井壁围岩应力分析提取影响斜井井壁稳定的主应力,结合岩石破坏的强度准则建立地层坍塌压力和破裂压力的测井预测模型.针对研究工区地质情况对模型进行适当修正,建立了该区安全钻井液密度窗口.通过精细解释测井资料预测的井壁稳定情况表明,测井资料能够较好地预测井壁的稳定性,为防止井漏、井塌等工程事故提供了重要依据.%Starting from the mechanic factors that influence wellbore stability, the main stress that influences well stability of inclined well is determined through borehole wall surrounding rock stress analysis, and combining with the intensity principle of rock damage, logging prediction model of formation caving pressure and fracture pressure is established. Certain modification is made to the model considering the geological conditions of the studied area, and density window of safe drilling fluid is established. The wellbore stability predicted by the fine interpretation of logging data shows that logging data can predict wellbore stability and provide criteria for the prevention of engineering accident, such as circulation loss, hole collapse, etc.

  16. Well logging interpretation of production profile in horizontal oil-water two phase flow pipes

    Science.gov (United States)

    Zhai, Lu-Sheng; Jin, Ning-De; Gao, Zhong-Ke; Zheng, Xi-Ke

    2012-03-01

    Due to the complicated distribution of local velocity and local phase hold up along the radial direction of pipe in horizontal oil-water two phase flow, it is difficult to measure the total flow rate and phase volume fraction. In this study, we carried out dynamic experiment in horizontal oil-water two phases flow simulation well by using combination measurement system including turbine flowmeter with petal type concentrating diverter, conductance sensor and flowpassing capacitance sensor. According to the response resolution ability of the conductance and capacitance sensor in different range of total flow rate and water-cut, we use drift flux model and statistical model to predict the partial phase flow rate, respectively. The results indicate that the variable coefficient drift flux model can self-adaptively tone the model parameter according to the oil-water two phase flow characteristic, and the prediction result of partial phase flow rate of oil-water two phase flow is of high accuracy.

  17. Development and demonstration of an enhanced spreadsheet-based well log analysis software. Final report, May 1998

    Energy Technology Data Exchange (ETDEWEB)

    Watney, W.L.; Doveton, J.H.; Guy, W.J.

    1998-10-01

    The Advanced Class Work Program is a field-based research and demonstration program for demonstration of advanced or improved technologies identified in the Department of Energy`s Class Field Demonstration Projects. The objective of the Advanced Class Work program is to conduct field demonstrations of technologies for which a small, incremental amount of work will produce or improve a transferable, useful technology for oil recovery. The goal of the program is to enhance the products of near-term Class projects and maximize the applicability and effectiveness of project results. PfEFFER (Petrofacies Evaluation of Formations For Engineering Reservoirs) is a well log analysis computer package. The software was tested and successfully applied in Schaben Field, a DOE Class 2 Field Demonstration Project to assist in improving reservoir characterization and assessing reservoir performance. PfEFFER v.1 was released in January, 1996 as a commercial spreadsheet-based well-log analysis program developed and distributed through the Kansas Geological Survey. The objectives of this project were: Task 1 -- Enhance the PfEFFER software package; Task 2 -- Develop major new modules to significantly augment PfEFFER capabilities; Task 3 -- Conduct field demonstration of software application using the necessary reservoir data acquired from oil operators and construct a database; and Task 4 -- Perform technology transfer activities that include workshops, reports, presentations, or other methods to communicate results to interested parties.

  18. Combination of Well-Logging Temperature and Thermal Remote Sensing for Characterization of Geothermal Resources in Hokkaido, Northern Japan

    Directory of Open Access Journals (Sweden)

    Bingwei Tian

    2015-03-01

    Full Text Available Geothermal resources have become an increasingly important source of renewable energy for electrical power generation worldwide. Combined Three Dimension (3D Subsurface Temperature (SST and Land Surface Temperature (LST measurements are essential for accurate assessment of geothermal resources. In this study, subsurface and surface temperature distributions were combined using a dataset comprised of well logs and Thermal Infrared Remote sensing (TIR images from Hokkaido island, northern Japan. Using 28,476 temperature data points from 433 boreholes sites and a method of Kriging with External Drift or trend (KED, SST distribution model from depths of 100 to 1500 m was produced. Regional LST was estimated from 13 scenes of Landsat 8 images. Resultant SST ranged from around 50 °C to 300 °C at a depth of 1500 m. Most of western and part of the eastern Hokkaido are characterized by high temperature gradients, while low temperatures were found in the central region. Higher temperatures in shallower crust imply the western region and part of the eastern region have high geothermal potential. Moreover, several LST zones considered to have high geothermal potential were identified upon clarification of the underground heat distribution according to 3D SST. LST in these zones showed the anomalies, 3 to 9 °C higher than the surrounding areas. These results demonstrate that our combination of TIR and 3D temperature modeling using well logging and geostatistics is an efficient and promising approach to geothermal resource exploration.

  19. Standardization of Well Logging Curve Metgods%测井曲线标准化方法研究

    Institute of Scientific and Technical Information of China (English)

    陈熹

    2015-01-01

    Because Changling depressed area has undergone 60 years of exploration and development, and coupled with differences in well site borehole conditions, logging suite, instrument calibration, the time of measurement and other factors, the logging curves exist system error. So in the study on reservoir parameters and effective thickness division, influence of these factors on raw data need be eliminated, it is necessary to standardize the log curve to ensure the rationality and reliability of interpretation results. Standardization of well logging curve method can be divided into two types of qualitative method and quantitative method. Qualitative methods mainly include standardization of histogram correction, average standardized correction and overlap figure standardized correction; Quantitative methods are trend surface analysis and correction. In this paper,using Matlap software, the trend surface method was used to carry out the logging curve standardization in the study area. The results show that the standardized correction with trend surface method can eliminate the adverse factors to accurately extract the logging curve in the various of useful geological information.%由于长岭凹陷区经过近60年的勘探开发,再加上井场井眼条件的差异、测井系列、仪器刻度、测量时间及操作者不同等因素,使得各测井曲线存在系统误差。因此在开展储层参数研究和有效厚度划分时,为消除这些非地层因素对原始资料的影响,有必要对测井曲线进行标准化,以保证解释结果的合理性与可靠性。测井曲线标准化方法可以分为定性和定量两种类型。其中定性方法主要包括直方图法标准化校正、均值法标准化校正和重叠图法标准化校正;定量方法则为趋势面分析校正法。本论文利用 Matlab 软件,采用趋势面方法对研究区域内的井进行测井曲线标准化。结果表明经过趋势面法标准化校正能够消

  20. Fuzzy model to predict porosity thought conventional well logs; Modelo Fuzzy para predicao de porosidade via perfis convencionais de poco

    Energy Technology Data Exchange (ETDEWEB)

    Mimbela, Renzo R.F.; Silva, Jadir C. [Universidade Estadual do Norte Fluminense (UENF), Macae, RJ (Brazil). Lab. de Engenharia e Exploracao do Petroleo (LENEP)

    2004-07-01

    The well logs have a great applicability in the search and evaluation of hydrocarbon. In this work we calculate porosities of the Namorado field with help of the 'Fuzzy Rule'. This is done segmenting jointly both the neutron ({phi}{sub N}) and density ({phi}{sub d}) porosities logs in groups with better relation of internal linearity. The grouping is processed keeping the best number of groups, which is efficiently chosen by a criterion related to the minimum value of 'Fuzzy Validity' measurement. As a first step, we choose the {phi}{sub N} and {phi}{sub d} values only at that depths where cores exist. To prevent picking measurements errors a previous data filtering is performed by selecting only the and their correspondent values that exhibit a maximum discrepancy with core porosity ({phi}{sub C}) around 5pu (porosity unit). A conventional average porosity {phi}{sub MED}, mixing {phi}{sub N} and {phi}{sub d} is calculated at each point, concerning its own lithological and fluids characteristics. Finally, an inversion algorithm is applied to indicate the best curve curve that fit linearly {phi}{sub C} vs. {phi}{sub MED}, {phi}{sub C} vs. {phi}{sub D} and {phi}{sub C} vs. {phi}{sub N}, and at the same time determines the values of the constants to be extrapolated in order to calculate the porosity of the whole field. (author)

  1. Integrated well log and 2-D seismic data interpretation to image the subsurface stratigraphy and structure in north-eastern Bornu (Chad) basin

    Science.gov (United States)

    Isyaku, Aminu A.; Rust, Derek; Teeuw, Richard; Whitworth, Malcolm

    2016-09-01

    Structural and stratigraphic mapping within the Bornu Basin in north east Nigeria was commonly carried out using traditional field geological methods. However, such traditional approaches remain inadequate in the semi-arid region characterised by topographically flat areas and lack of continuous bedrock outcrops that are mostly concealed beneath sand cover. Previous studies in the north-eastern part of the basin carried out using ditch cuttings from few wells and disconnected seismic data were largely inadequate and the resulting stratigraphic analyses were more often generalised. This paper presents an integrated structural and stratigraphic study of the basin using combined subsurface geophysical datasets. A Combined Log Pattern (CLP) method is a well log analysis, which utilises various well log data including gamma ray, resistivity, bulk density and sonic logs to identify lithology and stratigraphic boundaries of subsurface formations. This method is applied to constrain the subsurface stratigraphy of the north-eastern part of the Bornu Basin bordering the Lake Chad. In addition to qualitative combined well log analysis, the time-depth relationship of the sonic log and seismic data was quantitatively determined by tying a well with an intersecting seismic section to validate the stratigraphic facies horizons identified. Four well log facies and their environments of deposition were characterised from the combined well log analysis of the different log types. It is discovered that the Cretaceous basement structural features controlled the deposition of overlying formations in the basin. Without intact core data, the shallower wells were discovered to have bottomed over subsurface horst features while deeper wells penetrated into the basal facies contained mainly within the grabens. Main subsurface structural lineaments in the area include NW-SE, NE-SW and NNW-SSE trending faults, which mainly formed the horst and graben features. Some stratigraphic formations

  2. 测井信息管理系统设计与实现%Design and Implementation of Well Log Information Management System

    Institute of Scientific and Technical Information of China (English)

    赵林

    2014-01-01

    这篇文章描述了测井信息管理系统设计和实现。测井信息管理系统是基于测井数据管理和对测井数据进行图形化展示的系统。%This paper describes design and implementation of well log information management system. Well log information management system is a system which is based on oil field well log data, and graph display.

  3. Interpretation of digital well-logging for 'three zones' in coal mine area

    Energy Technology Data Exchange (ETDEWEB)

    Han, X.; Zhang, J. [Shandong Coalfield Geologic Bureau, Taian (China). Digital Well-logging Station

    2001-06-01

    During mine production, the development of caving, fractured and continuous depressing zones (also known as 'three zones') in the strata overlying the mined coal face following the removal of supports is a common phenomenon. The height at which the 'three zones' occurs would directly influence mine safety production, mining scope determination and environmental effects. Using the digital well-logging data obtained in Xinglongzhuang Coal Mine, the 'three zones' are systematically and comprehensively explained in this paper and their developmental conditions are determined. The study is beneficial for mine safety production, identification of mining scope and preservation of coal pillars. 2 refs., 3 figs.

  4. Interpretation of core and well log physical property data from drill hole UPH-3, Stephenson County, Illinois

    Science.gov (United States)

    Daniels, Jeffrey J.; Olhoeft, Gary R.; Scott, James H.

    1983-09-01

    Laboratory and well log physical property measurements show variations in the mineralogy with depth in UPH-3. Gamma ray values generally decrease with depth in the drill hole, corresponding to a decrease in the felsic mineral components of the granite. Correspondingly, an increase with depth in mafic minerals in the granite is indicated by the magnetic susceptibility and gamma ray measurements. These mineralogic changes indicated by the geophysical well logs support the hypothesis of fractionation during continuous crystalization of the intrusive penetrated by UPH-3. Two fracture zones and an altered zone within the granite penetrated by drill hole UPH-3 are defined by the physical property measurements. An abnormally low magnetic susceptibility response in the upper portion of the drill hole can be attributed to alteration of the rock adjacent to the sediments overlying the granite. Fracture zones can be identified from the sonic velocity, neutron, and resistivity measurements. A fracture zone, characterized by low resistivity values and low neutron values, is present in the depth interval from 1150 to 1320 m. Low magnetic susceptibility and high gamma ray values indicate the presence of felsic-micaceous pegmatites within this fracture zone. An unfractured region present from a depth of 1380 m to the bottom of the hole is characterized by an absence of physical property variations. The magnetic susceptibility and gamma ray measurements indicate a change in the amount of mafic minerals at the base of this otherwise homogenous region of the drilled interval. Abrupt changes and repeated patterns of physical properties within the drill hole may represent interruptions in the crystalization process of the melt or they may be indicative of critical temperatures for specific mineral assemblages within the intrusive.

  5. APPLICATION OF WELL LOG ANALYSIS IN ASSESSMENT OF PETROPHYSICAL PARAMETERS AND RESERVOIR CHARACTERIZATION OF WELLS IN THE “OTH” FIELD, ANAMBRA BASIN, SOUTHERN NIGERIA

    Directory of Open Access Journals (Sweden)

    Eugene URORO

    2014-12-01

    Full Text Available Over the past years, the Anambra basin one of Nigeria’s inland basins has recorded significant level of hydrocarbon exploration activities. The basin has been confirmed by several authors from source rock analyses to have the potential for generating hydrocarbon. For the hydrocarbon to be exploited, it is imperative to have a thorough understanding of the reservoir. Computer-assisted log analyses were employed to effectively evaluate the petrophysical parameters such as the shale volume (Vsh, total porosity (TP, effective porosity (EP, water saturation (Sw, and hydrocarbon saturation (Sh. Cross-plots of the petrophysical parameters versus depth were illustrated. Five hydrocarbon bearing reservoirs were delineated in well 1, four in well 2. The reservoirs in well 3 do not contain hydrocarbon. The estimated reservoir porosity varies from 10% to 21% while their permeability values range from 20md to 1400md. The porosity and permeability values suggest that reservoirs are good enough to store and also permit free flow of fluid. The volume of shale (0.05% to 0.35% analysis reveals that the reservoirs range from shaly sand to slightly shaly sand to clean sand reservoir. On the basis of petrophysics data, the reservoirs are interpreted a good quality reservoir rocks which has been confirmed with high effective porosity range between 20% and high hydrocarbon saturation exceeding 55% water saturation in well 1 and well 2. Water saturation 3 is nearly 100% although the reservoir properties are good.  

  6. Inference of S-wave velocities from well logs using a Neuro-Fuzzy Logic (NFL) approach

    Science.gov (United States)

    Aldana, Milagrosa; Coronado, Ronal; Hurtado, Nuri

    2010-05-01

    The knowledge of S-wave velocity values is important for a complete characterization and understanding of reservoir rock properties. It could help in determining fracture propagation and also to improve porosity prediction (Cuddy and Glover, 2002). Nevertheless the acquisition of S-wave velocity data is rather expensive; hence, for most reservoirs usually this information is not available. In the present work we applied a hybrid system, that combines Neural Networks and Fuzzy Logic, in order to infer S-wave velocities from porosity (φ), water saturation (Sw) and shale content (Vsh) logs. The Neuro-Fuzzy Logic (NFL) technique was tested in two wells from the Guafita oil field, Apure Basin, Venezuela. We have trained the system using 50% of the data randomly taken from one of the wells, in order to obtain the inference equations (Takani-Sugeno-Kang (TSK) fuzzy model). Equations using just one of the parameters as input (i.e. φ, Sw or Vsh), combined by pairs and all together were obtained. These equations were tested in the whole well. The results indicate that the best inference (correlation between inferred and experimental data close to 80%) is obtained when all the parameters are considered as input data. An increase of the equation number of the TSK model, when one or just two parameters are used, does not improve the performance of the NFL. The best set of equations was tested in a nearby well. The results suggest that the large difference in the petrophysical and lithological characteristics between these two wells, avoid a good inference of S-wave velocities in the tested well and allowed us to analyze the limitations of the method.

  7. Pre- and post-stimulation characterization of geothermal well GRT-1, Rittershoffen, France: insights from acoustic image logs of hard fractured rock

    Science.gov (United States)

    Vidal, Jeanne; Genter, Albert; Schmittbuhl, Jean

    2016-08-01

    Geothermal well GRT-1 (Rittershoffen, Alsace) was drilled in 2012. Its open-hole section (extending down to a depth of 2.6 km) penetrated fractured sandstones and granite. In 2013, the well was subjected to Thermal, Chemical and Hydraulic (TCH) stimulation, which improved the injectivity index fivefold. The goal of the study was to assess the impact of the stimulation by comparing pre- and post-stimulation well-logging (acoustic and temperature [T] logs) and mud-logging data. This comparison revealed modifications of almost all the natural fractures. However, not all of these fractures are associated with permeability enhancement, and the post-stimulation T logs are important for characterizing this enhancement. Chemical alteration due to mechanical erosion at the tops and bottoms of the fractures was observed in the sandstones. These zones display indications of very small new permeability after the TCH stimulation. Because a major fault zone caved extensively where it crosses the borehole, it was not imaged in the acoustic logs. However, this originally permeable zone was enhanced as demonstrated by the T logs. Based on the natural injectivity of this fault zone, hydraulic erosion and thermal microcracking of its internal quartz veins are associated with this permeability enhancement. Although local changes in the borehole wall observed in the acoustic images cannot be directly linked to the improved injectivity index, the comparison of the acoustic image logs allows for identification of fracture zones impacted by the TCH stimulation.

  8. A Study on the Classification and Well-Logging Identification of Eclogite in the Main Hole of Chinese Continental Scientific Drilling Project

    Institute of Scientific and Technical Information of China (English)

    Jing Jian'en; Wei Wenbo; Jin Sheng; Ye Gaofeng; Deng Ming

    2007-01-01

    Eclogite, one of the important lithologies in the main hole of the Chinese Continental Scientific Drilling (CCSD) Project, exists above the depth of 3 245 m and has distinctive responses of gamma-ray, compensating density and neutron well-logging, and so on. In this study, according to the diversities of minerals and chemical components and well-logging responses, eclogites are classified from three aspects of origin, content of oxygen, and sub-mineral. We studied the logging identification method for eclogite sub-classes based on multi-element statistics and reconstructed 11 kinds of eclogite.As a result, eclogites can be divided into 6 types using well logs. In the light of this recognition, the eclogite in the main hole is divided into 20 sections, and the distribution characters of all sub-classes of eclogite are analyzed, which will provide important data for geological research of CCSD.

  9. Petrophysical Evaluation of the Sarvak Formation Based on Well Logs in Dezful Embayment, Zagros Fold Zone, South West of Iran

    Directory of Open Access Journals (Sweden)

    A. Jooybari

    2017-02-01

    Full Text Available Dezful embayment in the south west of Iran is part of Zagros fold zone which despite the small area includes almost all of Iran oil production. Sarvak Formation with middle cretaceous (Albin-Turunin is the second biggest reservoir of Zagros basin, after the Asmari formation. In this study, with well logging data of two wells, by Geolog software, the petrophysical parameters of Sarvak Formation in the Dezful embayment was studied using the contingent Probabilistic method. Petrophysical parameters such as determination of porosity, water saturation, shale volume and lithology were calculated using this data and common cross plots. Based on this evaluation and utilizing cross plots result, the lithology of Sarvak formation in this zone was determined to be Limestone with traces of dolomite and shale. According to the calculated petrophysical properties of the reservoir, and for more accurate assessment, Sarvak Formation was divided to 6 sections. Findings of this research show that Sarvak Formation includes good reservoir parameters only in half its sections (sections 4, 2 and 6.

  10. Oil & Natural Gas Technology A new approach to understanding the occurrence and volume of natural gas hydrate in the northern Gulf of Mexico using petroleum industry well logs

    Energy Technology Data Exchange (ETDEWEB)

    Cook, Ann [The Ohio State Univ., Columbus, OH (United States); Majumdar, Urmi [The Ohio State Univ., Columbus, OH (United States)

    2016-03-31

    The northern Gulf of Mexico has been the target for the petroleum industry for exploration of conventional energy resource for decades. We have used the rich existing petroleum industry well logs to find the occurrences of natural gas hydrate in the northern Gulf of Mexico. We have identified 798 wells with well log data within the gas hydrate stability zone. Out of those 798 wells, we have found evidence of gas hydrate in well logs in 124 wells (15% of wells). We have built a dataset of gas hydrate providing information such as location, interval of hydrate occurrence (if any) and the overall quality of probable gas hydrate. Our dataset provides a wide, new perspective on the overall distribution of gas hydrate in the northern Gulf of Mexico and will be the key to future gas hydrate research and prospecting in the area.

  11. Determination of petrophysical properties of geothermal reservoirs in southern Denmark by integrating information from well logs and reflection seismic data

    Science.gov (United States)

    Rasmussen, Marie L.; Balling, Niels; Bording, Thue S.; Clausen, Ole R.

    2013-04-01

    As part of the efforts to reduce CO2 emission, geothermal energy is an important source for future energy production in Denmark, and several research programs deal with this specific subject e.g. "The geothermal energy potential in Denmark - reservoir properties, temperature distribution and models for utilization", funded by the Danish Strategic Research Council and "GEOPOWER" which is part of an EU INTERREG-program focused on southern Denmark and northernmost Germany. For geothermal energy to be economically sustainable porous and permeable rocks needs to be present at a depth where the temperature is sufficiently high. Utilization of geothermal energy in Denmark and plans for the future are concentrated on low enthalpy basin reservoirs for district heating. Major modeling studies are carried out to establish the temperature distribution in the Danish subsurface. This project deals with the reservoir properties. The geothermal reservoir exploited so far in the southern Danish area is restricted to the lower Jurassic-Triassic Gassum Formation. The Gassum Formation is a shallow marine to fluvial deposit composed of sandy to silty sediments, occasionally with coal layers, i.e. a lateral and stratigraphically heterogeneous rock. This formation is encountered only in deep hydrocarbon exploration wells and in wells of the Sønderborg Geothermal plant. Due to the very low number and low density of wells and the limited rock material recovered during drilling, the knowledge of lateral variations of reservoir properties in terms of porosity, permeability and thickness, is limited and so far unsatisfactorily mapped. The main risks in the utilization of geothermal energy from the subsurface of Denmark are therefore regional, as well as local, variations in the production potential of warm water, whereas the temperature can be assessed fairly precisely due to the thermal models available. Here we use petrophysical wells logs available from hydrocarbon exploration wells for

  12. Geophysical-log and hydraulic-test analyses of groundwater-production wells at the Hannahville Indian Community, Menominee County, Michigan

    Science.gov (United States)

    Bayless, E. Randall; Anderson, J. Alton; Lampe, David C.; Williams, John H.

    2013-01-01

    The U.S. Geological Survey, in cooperation with the Hannahville Indian Community, evaluated the geohydrology of the bedrock formations and hydraulic properties of groundwater-production wells at the Hannahville Indian Community in Menominee County, Michigan. Geophysical logs were collected from five wells at two sites during September 2012. The logs were analyzed to characterize the lithostratigraphy, bedding and fractures, and hydraulic properties of the geologic formations and aquifers beneath the Hannahville Indian Community. The geophysical logs collected included natural gamma radiation, electromagnetic conductivity, wellbore image, caliper, ambient and stressed flowmeter, fluid resistivity, temperature, and wellbore deviation. The geophysical logs were analyzed with results from short-term hydraulic tests to estimate the transmissivity and water-level altitudes of flow zones penetrated by the wells. The geophysical log analysis indicated the wells penetrated four distinct lithostratigraphic units—shale and carbonate rock, upper carbonate rock, carbonate rock and glauconitic sandstone, and lower carbonate rock. Most of the fractures penetrated by the wellbores appeared to be related bedding partings. The lower carbonate rock unit contained solution features. Analysis of the geophysical logs and hydraulic tests indicated that each of the five wells penetrated from one to four flow zones. The Casino 5 well penetrated a flow zone that was associated with solution features and had an estimated total transmissivity of 4,280 feet squared per day (ft2/d), the highest estimate for all the wells. The Casino 3 well penetrated four flow zones and had an estimated total transmissivity of 3,570 ft2/d. The flow zones penetrated in the lower carbonate rock unit by the Casino 3 and 5 wells were hydraulically connected. The Golf Shack well penetrated two flow zones and had an estimated total transmissivity of 40 ft2/d, the lowest estimate for all the wells. The Community 1

  13. Electrofacies in gas shale from well log data via cluster analysis: A case study of the Perth Basin, Western Australia

    Science.gov (United States)

    Torghabeh, Amir; Rezaee, Reza; Moussavi-Harami, Reza; Pradhan, Biswajeet; Kamali, Mohammad; Kadkhodaie-Ilkhchi, Ali

    2014-09-01

    Identifying reservoir electrofacies has an important role in determining hydrocarbon bearing intervals. In this study, electrofacies of the Kockatea Formation in the Perth Basin were determined via cluster analysis. In this method, distance data were initially calculated and then connected spatially by using a linkage function. The dendrogram function was used to extract the cluster tree for formations over the study area. Input logs were sonic log (DT), gamma ray log (GR), resistivity log (IND), and spontaneous potential (SP). A total of 30 reservoir electrofacies were identified within this formation. Integrated geochemical and petrophysics data showed that zones with electrofacies 3, 4, 9, and 10 have potential for shale gas production. In addition, the results showed that cluster analysis is a precise, rapid, and cost-effective method for zoning reservoirs and determining electrofacies in hydrocarbon reservoirs.

  14. Application of horizontal well logging technology in XP-1%水平井测井技术在XP-1井中应用

    Institute of Scientific and Technical Information of China (English)

    裴英铁; 徐艳华

    2012-01-01

    The horizontal well is different from conventional vertical well in well logging,logging interpretation and reservoir evaluation.Based on the environment and thickness change of the reservoir,in horizontal well drilling,discussed curve response features and logging interpretation features of the horizontal well logging,presented that must accurately judge borehole trajectory in the horizontal well logging interpretation process,in order to correctly identify reservoir and guide the production test.%水平井在测井作业、测井解释及储层评价方面与常规铅直井有所不同。本文从水平井钻遇的储层周围环境和储层厚度变换入手,论述了水平井储层测井曲线响应特征和测井解释特点,提出在水平井测井解释过程中须准确判断出井眼轨迹,以便正确识别储层及指导生产测试。

  15. Main Points and Methods of CBM Well Logging Supervision%煤层气测井监理要点及方法

    Institute of Scientific and Technical Information of China (English)

    孙敏; 韩德林

    2013-01-01

    The quality of CBM well logging is directly connected with if the subsequent handlings can be carried out normally.For this reason,well logging supervision personnel should have proven unscramble and resolving abilities on parameter traces logged.Then,as a newly developed profession,the CBM well logging supervision has not yet formed a unified theory and methodology.Through analysis of similarities and differences between coal logging and CBM logging,has considered that working methods of coal logging supervision and CBM logging supervision are widely divergent; the focal point of the former is on coal seams,while besides coal and rock interpretation,the later is more focused on reliability evaluation of logging traces per se.According to the peculiarity of CBM logging supervision,the focal contents of inspection and corresponding improving measures on different logging traces put forward.%煤层气测井质量的好坏直接关联到后续工序能否正常开展,为此要求煤层气测井监理对所测参数曲线具有较强的解读和鉴别能力.然则作为新兴行业,煤层气测井监理尚未形成统一的理论和方法.通过分析打煤孔测井与煤层气测井的共性与差异,认为打煤孔测井监理与煤层气井测井监理的工作方法大相径庭,前者重点在于煤层,后者除要求煤岩解释外更侧重于曲线本身的可信度评价.根据煤层气测井监理的特点,提出了对不同测井曲线进行监理时应重点检查的内容及相应的改进措施.

  16. Well logging identification of gypsum cap rocks in middle-upper Yangtze region%中上扬子区膏岩盖层的测井识别

    Institute of Scientific and Technical Information of China (English)

    冯琼; 魏水建

    2011-01-01

    针对中、上扬子区膏岩盖层测井响应特征,充分利用地质、录井、岩心分析、测井等资料,采用岩心刻度测井的方法,建立了膏岩盖层参数测井解释模型,并对该区膏岩盖层进行了测井解释与评价;建立了一套适合川东北地区膏岩盖层的测井识别方法,从而实现了盖层从定性识别到盖层参数的定量评价,为盖层的地球物理预测研究提供了重要的基础参数.%Based on well logging response characteristics of gypsum cap rocks in the middle- upper Yangtze region, with geology, well logging, core analysis and logging data, it was established in this paper a logging interpretation model of gypsum cap rock parameters using the core calibration logging method.The gypsum cap rocks in the study region were interpreted and evaluated. A new set of logging identification method suitable for gypsum cap rocks in the Northeast Sichuan Basin was put forward. The qualitative identification and the quantitative evaluation of cap rocks were done, offering important basis parameters for the geophysical prediction researches of cap rocks.

  17. Inference of strata separation and gas emission paths in longwall overburden using continuous wavelet transform of well logs and geostatistical simulation

    Science.gov (United States)

    Karacan, C. Özgen; Olea, Ricardo A.

    2014-06-01

    Prediction of potential methane emission pathways from various sources into active mine workings or sealed gobs from longwall overburden is important for controlling methane and for improving mining safety. The aim of this paper is to infer strata separation intervals and thus gas emission pathways from standard well log data. The proposed technique was applied to well logs acquired through the Mary Lee/Blue Creek coal seam of the Upper Pottsville Formation in the Black Warrior Basin, Alabama, using well logs from a series of boreholes aligned along a nearly linear profile. For this purpose, continuous wavelet transform (CWT) of digitized gamma well logs was performed by using Mexican hat and Morlet, as the mother wavelets, to identify potential discontinuities in the signal. Pointwise Hölder exponents (PHE) of gamma logs were also computed using the generalized quadratic variations (GQV) method to identify the location and strength of singularities of well log signals as a complementary analysis. PHEs and wavelet coefficients were analyzed to find the locations of singularities along the logs. Using the well logs in this study, locations of predicted singularities were used as indicators in single normal equation simulation (SNESIM) to generate equi-probable realizations of potential strata separation intervals. Horizontal and vertical variograms of realizations were then analyzed and compared with those of indicator data and training image (TI) data using the Kruskal-Wallis test. A sum of squared differences was employed to select the most probable realization representing the locations of potential strata separations and methane flow paths. Results indicated that singularities located in well log signals reliably correlated with strata transitions or discontinuities within the strata. Geostatistical simulation of these discontinuities provided information about the location and extents of the continuous channels that may form during mining. If there is a gas

  18. Correlating Petrophysical Well Logs Using Fractal-based Analysis to Identify Changes in the Signal Complexity Across Neutron, Density, Dipole Sonic, and Gamma Ray Tool Types

    Science.gov (United States)

    Matthews, L.; Gurrola, H.

    2015-12-01

    Typical petrophysical well log correlation is accomplished by manual pattern recognition leading to subjective correlations. The change in character in a well log is dependent upon the change in the response of the tool to lithology. The petrophysical interpreter looks for a change in one log type that would correspond to the way a different tool responds to the same lithology. To develop an objective way to pick changes in well log characteristics, we adapt a method of first arrival picking used in seismic data to analyze changes in the character of well logs. We chose to use the fractal method developed by Boschetti et al[1] (1996). This method worked better than we expected and we found similar changes in the fractal dimension across very different tool types (sonic vs density vs gamma ray). We reason the fractal response of the log is not dependent on the physics of the tool response but rather the change in the complexity of the log data. When a formation changes physical character in time or space the recorded magnitude in tool data changes complexity at the same time even if the original tool response is very different. The relative complexity of the data regardless of the tool used is dependent upon the complexity of the medium relative to tool measurement. The relative complexity of the recorded magnitude data changes as a tool transitions from one character type to another. The character we are measuring is the roughness or complexity of the petrophysical curve. Our method provides a way to directly compare different log types based on a quantitative change in signal complexity. For example, using changes in data complexity allow us to correlate gamma ray suites with sonic logs within a well and then across to an adjacent well with similar signatures. Our method creates reliable and automatic correlations to be made in data sets beyond the reasonable cognitive limits of geoscientists in both speed and consistent pattern recognition. [1] Fabio Boschetti

  19. Seismic Interpretation and Well Logging Results of a Deep Borehole into the Canadian Shield in Northeastern Alberta: Preliminary Results

    Science.gov (United States)

    Chan, J.; Schmitt, D.; Majorowicz, J. A.; Nieuwenhuis, G.; Poureslami Ardakani, E.; van der Baan, M.; Sahay, P. N.; Kueck, J.; Abasolo, M. R.

    2011-12-01

    information about the reflectivity and the velocity structure of the subsurface. The full integration of surface seismic data, VSP data, and well logs are expected to provide a detailed characterization of the sedimentary basin and crystalline basement rocks of the Canadian Shield in Northeastern Alberta. In particular, the unusually low fluid pressures in the well may be related to states of stress that are likely still influenced by post-glacial rebound.

  20. Determination of Shale Volume and Distribution Patterns and Effective Porosity from Well Log Data Based On Cross-Plot Approach for A Shaly Carbonate Gas Reservoir

    Science.gov (United States)

    Moradi, Siyamak; Moeini, Mohammad; Kamal Ghassem al-Askari, Mohammad; Hamed Mahvelati, Elaheh

    2016-10-01

    Determination of shale volume distribution is one of the most important factors that has to be considered in formation evaluation, since existence of shale reduces effective porosity and permeability of the reservoir. In this paper, shale volume and distribution (dispersed, laminar and structural) and formation effective porosity are estimated from well log data and cross-plots. Results show that distribution of shale is mainly dispersed with few of laminar ones, and the quality of reservoir (effective porosity) decreases with depth resulting in low productivity of gas wells drilled in lower zones. Good agreement of estimated shale volumes and effective porosities from neutron-density cross-plot with the values determined from gamma ray log (CGR) and core analysis demonstrates the accuracy and applicability of these plots in determination of petrophysical parameters from conventional log data.

  1. Hydrogeologic Framework of the Upper Santa Cruz Basin (Arizona and Sonora) using Well Logs, Geologic Mapping, Gravity, Magnetics, and Electromagnetics

    Science.gov (United States)

    Callegary, J. B.; Page, W. R.; Megdal, S.; Gray, F.; Scott, C. A.; Berry, M.; Rangel, M.; Oroz Ramos, L.; Menges, C. M.; Jones, A.

    2011-12-01

    In 2006, the U.S. Congress passed the U.S.-Mexico Transboundary Aquifer Assessment Act which provides a framework for study of aquifers shared by the United States and Mexico. The aquifer of the Upper Santa Cruz Basin was chosen as one of four priority aquifers for several reasons, including water scarcity, a population greater than 300,000, groundwater as the sole source of water for human use, and a riparian corridor that is of regional significance for migratory birds and other animals. Several new mines are also being proposed for this area which may affect water quality and availability. To date, a number of studies have been carried out by a binational team composed of the U.S. Geological Survey, the Mexican National Water Commission, and the Universities of Arizona and Sonora. Construction of a cross-border hydrogeologic framework model of the basin between Amado, Arizona and its southern boundary in Sonora is currently a high priority. The relatively narrow Santa Cruz valley is a structural basin that did not experience the same degree of late Cenozoic lateral extension and consequent deepening as found in other basin-and-range alluvial basins, such as the Tucson basin, where basin depth exceeds 3000 meters. This implies that storage may be much less than that found in other basin-and-range aquifers. To investigate the geometry of the basin and facies changes within the alluvium, a database of over one thousand well logs has been developed, geologic mapping and transient electromagnetic (TEM) surveys have been carried out, and information from previous electromagnetic, magnetic, and gravity studies is being incorporated into the hydrogeologic framework. Initial geophysical surveys and analyses have focused on the portion of the basin west of Nogales, Arizona, because it supplies approximately 50% of that city's water. Previous gravity and magnetic modeling indicate that this area is a narrow, fault-controlled half graben. Preliminary modeling of airborne

  2. Application of well log analysis for source rock evaluation in the Duwi Formation, Southern Gulf of Suez, Egypt

    Science.gov (United States)

    El Sharawy, Mohamed S.; Gaafar, Gamal R.

    2012-05-01

    Several models were developed to use the conventional wireline logs for evaluating the thermal maturity of the source rock and calculating the total organic carbon (TOC) content. Application of these models for the Duwi Formation, southern Gulf of Suez, Egypt, is the main purpose of this paper. Gamma ray, density, sonic, resistivity and neutron are the commonly used wireline logs to identify and quantify source rock. The results, which compared with the results obtained from the Rock-Eval pyrolysis show that cautions must be taken into consideration when applied these models because most of the models are empirical and their validation takes place under certain conditions. It can be concluded that the Duwi Formation represents very good source rock capable of generating a significant amount of hydrocarbon of oil-prone type II. The kerogen is waxy sapropel related to marine plankton deposited under reduced condition.

  3. Digital signal processing and interpretation of full waveform sonic log for well BP-3-USGS, Great Sand Dunes National Park and Preserve, Alamosa County, Colorado

    Science.gov (United States)

    Burke, Lauri

    2011-01-01

    Along the Great Sand Dunes National Park and Preserve boundary (fig. 1), 10 monitoring wells were drilled by the National Park Service in order to monitor water flow in an unconfined aquifer spanning the park boundary. Adjacent to the National Park Service monitoring well named Boundary Piezometer Well No. 3, or BP-3, the U.S. Geological Survey (USGS) drilled the BP-3-USGS well. This well was drilled from September 14 through 17, 2009, to a total depth of 99.4 meters (m) in order to acquire additional subsurface information. The BP-3-USGS well is located at lat 37 degrees 43'18.06' and long -105 degrees 43'39.30' at a surface elevation of 2,301 m. Approximately 23 m of core was recovered beginning at a depth of 18 m. Drill cuttings were also recovered. The wireline geophysical logs acquired in the well include natural gamma ray, borehole caliper, temperature, full waveform sonic, density, neutron, resistivity, and induction logs. The BP-3-USGS well is now plugged and abandoned. This report details the full waveform digital signal processing methodology and the formation compressional-wave velocities determined for the BP-3-USGS well. These velocity results are compared to several velocities that are commonly encountered in the subsurface. The density log is also discussed in context of these formation velocities.

  4. 水平井测井工艺技术在江苏油田的应用研究%Application of horizontal well logging in Jiangsu oilfield

    Institute of Scientific and Technical Information of China (English)

    范占煊

    2015-01-01

    本文以江苏为例,展开对水平井测井工艺技术的研究与讨论,并对湿接头的水平井工艺的优缺点进行分析。%Horizontal well logging is introduced in this paper by citing the practices of Jiangsu Oilfield,the pros and cons of wet-connector technology is analyzed as well.

  5. 水平井测井解释技术的研究与应用%Research and Application of Technology on Log Interpretation of Horizontal Wells

    Institute of Scientific and Technical Information of China (English)

    法林; 何兆普; 丁鹏飞; 张学良; 袁龙刚; 李白; 赖小虎

    2015-01-01

    为了精确地解释水平井的测井数据,建立了简化的声波测井物理模型,结合FFT等数字信号处理算法,利用Matlab语言模拟了不同地层孔隙度包含不同流体的情况下所接收到的声波测井信号子波的区别,提出了水平井周围介质特性的反演方法。该方法可用来分析和判定油水分布。将该方法程序化,开发了一套声波测井全信息精确分析软件。使用该软件对国内油田10余口油井的测井资料进行反演,分析解释出水井段,成功率在90%以上,生产效率得到明显提高。%In order to accurately interpret the logging data of horizontal well ,a simplified physical model of acoustic-logging is established combining with FFT and other digital signal processing algorithms , and an inversion algorithm was proposed for the property of medium a-round horizontal well .For the case of different porosity formation containing different fluid , the received acoustic-logging signal wavelet was calculated by employing Matlab language .Based on the above algorithm , the inversion interpretation software of acoustic-logging data was developed.Using this set of software to perform the inversion interpretations of logging data of more than 10 oil wells, the success rate is o-ver 90%, and the production efficiency is increased obviously .

  6. P.S测井技术的工程应用%THE APPLICATION OF WELL-LOGGING WITH P AND S WAVE IN GEOTECHNICAL ENGINEERING

    Institute of Scientific and Technical Information of China (English)

    刘康和

    2001-01-01

    Well-logging technique with P and S wave is one of seismic exploration methods.It is an easy,rapid and accurate method of in-situ measurement.Through measuring elastic wave velocity of rock and soil layers with P and S wave well logging technique,we can supply elastic dynamic parameters for engineering design,plot out the site grade of building,evaluate earthquake's effcet,analyze site earthquake response and potential damages.The working principles,field observing techniques,data processing and analysis about P and S wave well-logging technique are briefly introduced.In the end we illustrated the application of P and S wave well-logging method and its effect in geotechnical engineering investigation and design with two practical examples.%P.S测井技术是地震勘探方法之一,也是一种简便、快速、准确的原位测试技术。通过P.S测井可测定岩土体的弹性波速(Vp、Vs),为工程设计提供所需的动弹性力学参数、划分建筑物场地类别、评价地震效应、进行场地地震反应分析和地震破坏潜势分析等。文中简述了P.S测井技术的工作原理、现场实测技术以及数据处理和资料分析过程。最后结合两个实例说明了P.S测井技术在岩土工程勘察设计中的应用及其效果。

  7. Automatic lithofacies segmentation from well-logs data. A comparative study between the Self-Organizing Map (SOM) and Walsh transform

    Science.gov (United States)

    Aliouane, Leila; Ouadfeul, Sid-Ali; Rabhi, Abdessalem; Rouina, Fouzi; Benaissa, Zahia; Boudella, Amar

    2013-04-01

    The main goal of this work is to realize a comparison between two lithofacies segmentation techniques of reservoir interval. The first one is based on the Kohonen's Self-Organizing Map neural network machine. The second technique is based on the Walsh transform decomposition. Application to real well-logs data of two boreholes located in the Algerian Sahara shows that the Self-organizing map is able to provide more lithological details that the obtained lithofacies model given by the Walsh decomposition. Keywords: Comparison, Lithofacies, SOM, Walsh References: 1)Aliouane, L., Ouadfeul, S., Boudella, A., 2011, Fractal analysis based on the continuous wavelet transform and lithofacies classification from well-logs data using the self-organizing map neural network, Arabian Journal of geosciences, doi: 10.1007/s12517-011-0459-4 2) Aliouane, L., Ouadfeul, S., Djarfour, N., Boudella, A., 2012, Petrophysical Parameters Estimation from Well-Logs Data Using Multilayer Perceptron and Radial Basis Function Neural Networks, Lecture Notes in Computer Science Volume 7667, 2012, pp 730-736, doi : 10.1007/978-3-642-34500-5_86 3)Ouadfeul, S. and Aliouane., L., 2011, Multifractal analysis revisited by the continuous wavelet transform applied in lithofacies segmentation from well-logs data, International journal of applied physics and mathematics, Vol01 N01. 4) Ouadfeul, S., Aliouane, L., 2012, Lithofacies Classification Using the Multilayer Perceptron and the Self-organizing Neural Networks, Lecture Notes in Computer Science Volume 7667, 2012, pp 737-744, doi : 10.1007/978-3-642-34500-5_87 5) Weisstein, Eric W. "Fast Walsh Transform." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/FastWalshTransform.html

  8. Environmental Monitoring, Other - GAMMA_RAY_LOGS_IGS_IN: Wells with Natural Gamma-Ray Logs or Physical Samples in Unconsolidated Sediments in Indiana (Indiana Geological Survey, 1:100,000, Point Shapefile)

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — GAMMA_RAY_LOGS_IGS_IN.shp shows the locations of the Indiana Geological Survey's natural gamma-ray logs that were collected from 1978 to 2012. It was updated by...

  9. Analysis of Common Influencing Factors of Well Logging Curve%测井曲线常见影响因素分析

    Institute of Scientific and Technical Information of China (English)

    张文博; 宋晓莉

    2015-01-01

    There are many common influencing factors in well logging curve, no matter how well logging instrument developed, the common influencing factors are still exists. Identify and solve those influence factors contribute to improve the quality of the original well logging curve. Base on the past experience of practice, This paper analyses the factors of spontaneous potential, electrode of 4 meters,microelec-trode, acoustic, gamma, dual induction and gives the method of resolving the problems.%测井曲线常见影响因素很多,不管测井仪器如何发展,这些常规的影响因素依然存在,认识和解决这些影响因素对于提高测井原始曲线质量有着至关重要的作用。文章根据作者多年的现场经验,分析了自然电位、4m电极、微电极、声波、伽马和感应曲线的影响因素,并给出了解决这些异常曲线的方法。

  10. Staged Log Data Normalization in Dense Well Pattern%密井网区测井资料分期标准化方法

    Institute of Scientific and Technical Information of China (English)

    柴愈坤; 王志章; 李汉林

    2013-01-01

    经历多期勘探开发的密井网区其各期的井网测井条件存在着很大差异.利用不同条件下的测井资料进行地质解释会导致地质结论的不确定性;对多期勘探开发的测井资料统一进行标准化处理,同样会造成测井资料刻度误差.提出对密井网区采用分不同时期井网,用均值趋势面法进行测井资料标准化的方法,给出分期井网标准层测井响应均值趋势面分析方法.对大庆×区块按布井时间先后顺序的6个时期的井网704口井的声波时差采用标准层声波时差均值趋势面分析方法进行分期井网标准化,消除了非地质因素的影响,统一了全区声波时差的刻度标准.该方法应用效果较好,可为测井解释提供较准确的数据.%In dense well pattern which has been explorated and developed for a long time, the log data varies in different stages. When making geologic interpretations with different stage log data, the results often have multi-solutions. Errors in calibration will also appear when normalizing different stage log data. Therefore, this paper proposes the idea that using trend surface analysis method to normalize the log data in different stages separately, and provides the effect analysis methods. In × block of Daqing oilfield, trend surface analysis method is used to normalize the acoustic time mean value of 704 wells at six different stages. The normalization shows that this method eliminates the non-geology factors and unifies the calibration standard of acoustic log data. The good application effect indicates that it can provide reliable data for well-log interpretation.

  11. The specific purpose Monte Carlo code McENL for simulating the response of epithermal neutron lifetime well logging tools

    Energy Technology Data Exchange (ETDEWEB)

    Prettyman, T.H.; Gardner, R.P.; Verghese, K. (North Carolina State Univ., Raleigh, NC (United States). Center for Engineering Applications and Radioisotopes)

    1993-08-01

    A new specific purpose Monte Carlo code called McENL for modeling the time response of epithermal neutron lifetime tools is described. The code was developed so that the Monte Carlo neophyte can easily use it. A minimum amount of input preparation is required and specified fixed values of the parameters used to control the code operation can be used. The weight windows technique, employing splitting and Russian Roulette, is used with an automated importance function based on the solution of an adjoint diffusion model to improve the code efficiency. Complete composition and density correlated sampling is also included in the code and can be used to study the effect on tool response of small variations in the formation, borehole, or logging tool composition and density. An illustration of the latter application is given here for the density of a thermal neutron filter. McENL was benchmarked against test-pit data for the Mobil pulsed neutron porosity (PNP) tool and found to be very accurate. Results of the experimental validation and details of code performance are presented.

  12. X井礁滩储层测井精细评价%Refined logging evaluation of reservoirs of reef and beach facies in the well LG1

    Institute of Scientific and Technical Information of China (English)

    张树东; 齐宝权; 贺洪举; 杨仁林; 罗利; 周肖; 刘萍英

    2009-01-01

    在介绍四川盆地东北地区下三叠统飞仙关组和上二叠统生物礁测井解释的经验和技术基础上,对X井飞仙关组、长兴组的地质和储层特征进行了对比分析,并充分利用该井的常规测井和成像测井的信息,精细地评价了该井的礁滩储层,准确地进行了气水解释,较为精确地获得了储层的参数.研究认为:在飞仙关和长兴组同时找到的礁滩叠合体具有储层发育程度高、溶蚀作用强、产量高的特点,具有较大的勘探潜力,这也得到了试油结果的验证;有效的测井组合是常规测井、电阻率成像、阵列声波、重复式地层测试器,可选择的是核磁共振测井,该井气层的测井解释成功为LG地区油气勘探提供了技术支持.%The discovery of the well LG1 is one of the major exploration achievements by the PetroChina Southwest Oil & Gasfield Company. After introducing the experiences and technologies of log interpretation for the bioherm reservoirs in the Lower Triassic Feixianguan Formation and the Upper Permian in northeastern Sichuan Basin, we performed a comparative analysis of the geologic and reservoir characteristics of the Feixianguan and Changxing formations in the well LG1, and performed detailed evaluation of the reservoirs of reef and beach facies in this well, accurately identified the gas and water layers, and obtained relatively accurate reservoir parameters by fully utilizing the conventional well and image logging data. The following results are achieved. The complexity of reef and beach facies identified in both Feixianguan and Changxing formations are characterized by well-developed reservoirs, strong dissolution, and high deliverability, thus they have large exploration potentials which have been proved by oil testing results. The effective logging suit consists of conventional log, resistivity image log, array sonic log, repeated drill-stem tester, with nuclear magnetic resonance log as the option. The

  13. 20世纪90年代核测井进展%Advances of Nuclear Well Logging in 1990s

    Institute of Scientific and Technical Information of China (English)

    彭琥

    2001-01-01

    Having surveyed 240 articles presented in 1990~1999, this review summarizes the main advances in nuclear well logging (NWL) in 1990s. It stresses on domestic and overseas“hot points” of research and development, such as nuclear porosity logging series, pulsed neutron time spectrum logging, pulsed neutron gamma energy spectrum logging, radioactive tracer logging, as well as the computerized numerical simulation technique applied in NWL. Methodologies and tools,which synthetically acquire and process the space-time-energy data of radioactive field, are presently at the front of research and development. Mainly attacking the logging in complex conditions and production logging while aiming at accuracy and precision of measurement as the key target, the main growing points of NWL in the near future keep on being as follows: methodological creation of raw data acquiring and processing and log analyzing, as well as development and application of computerized numerical simulation technique. In addition, attention to the metrological property of NWL tools should be emphasized greatly, while the quality of hardware of domestic NWL tools should be enhanced continuously. 40 pieces of references are enclosed.%通过对国内外1990~1999年间发表的240多篇有关放射性测井方面论文的分析,综述了20世纪90年代核测井的发展概况,重点介绍了核孔隙度测井系列、脉冲中子时间谱测井、脉冲中子伽马能谱测井、放射性同位素示踪测井以及核测井计算机数值模拟技术等国内外研究发展热点的主要进展。认为,对核辐射场信息作空间-时间-能量综合采集和分析的方法和仪器处在当前研究前沿;以测量精确度为核心,主攻复杂条件测井和生产测井、原始测量数据采集处理方法和解释方法创新以及计算机数值模拟技术开发和应用等仍将是今后一段时期中核测井的发展重点。此外,国内还应继续狠抓

  14. 基于操作日志的完井数据同步模型%Well Completion Business Data Synchronization Model Research Based on Operation Log

    Institute of Scientific and Technical Information of China (English)

    吴雅娟; 任占广; 杜睿山

    2015-01-01

    同步技术是提高移动数据库系统性能的一项关键技术。依托完井移动平台,结合完井业务数据,提出一种基于操作日志的移动数据同步处理模型,重点分析了该模型中的日志序列的生成以及冲突的消解,并给出了具体的实现算法。该模型允许移动终端在断接状态下对本地副本数据进行操作,并通过移动事务日志记录用户行为,当重新连接时,根据服务器返回的日志序列进行同步处理,使系统最终收敛于一致性状态。同时还引入了日志合并、时间戳等方法,有效减少了移动终端的资源消耗,提高了同步效率。实验表明该算法能快速高效地完成客户端与服务器之间的数据更新与交互。%Synchronization technology is one of the key techniques to promote the performance of mobile database systems. This paper which relied on the well completion mobile platform and integrated the well completion business data proposed a mobile data synchronization model which is based on operation log. In this model, the generation of log sequences, and the resolution of conflicts are discussed in detail, and the implementation algorithm is proposed. In this model, mobile devices are allowed to access the local copy data and locally commit the mobile transactions when the system is disconnected, meanwhile the user behavior can also be recorded in the mobile transaction log. According to the log sequence which is returned by the synchronous server, the mobile devices can update the local data when the system is reconnected to ensure the consistency of data. Besides, by introducing the merger of log and time-stamp into the model, the model can reduce the resource consumption, and improve the efficiency of the synchronization. The experiments proved that the algorithm can exchange the well completion business data between mobile devices and synchronization server rapidly and efficiently.

  15. Geophysical Logs, Specific Capacity, and Water Quality of Four Wells at Rogers Mechanical (former Tate Andale) Property, North Penn Area 6 Superfund Site, Lansdale, Pennsylvania, 2006-07

    Science.gov (United States)

    Senior, Lisa A.; Bird, Philip H.

    2010-01-01

    As part of technical assistance to the U.S. Environmental Protection Agency (USEPA) in the remediation of properties on the North Penn Area 6 Superfund Site in Lansdale, Pa., the U.S. Geological Survey (USGS) in 2006-07 collected data in four monitor wells at the Rogers Mechanical (former Tate Andale) property. During this period, USGS collected and analyzed borehole geophysical and video logs of three new monitor wells (Rogers 4, Rogers 5, and Rogers 6) ranging in depth from 80 to 180 feet, a borehole video log and additional heatpulse-flowmeter measurements (to quantify vertical borehole flow) in one existing 100-foot deep well (Rogers 3S), and water-level data during development of two wells (Rogers 5 and Rogers 6) to determine specific capacity. USGS also summarized results of passive-diffusion bag sampling for volatile organic compounds (VOCs) in the four wells. These data were intended to help understand the groundwater system and the distribution of VOC contaminants in groundwater at the property.

  16. 存储式井温仪在产出剖面测井中的应用%Application of storage type well thermometer in production profile logging

    Institute of Scientific and Technical Information of China (English)

    姜飞

    2014-01-01

    本文简要介绍了存储式井温仪的工作原理,重点分析了存储式井温仪在产出剖面测井中的应用效果,并与环空井温压力短节测试出的井温曲线进行对比,阐述了存储式井温仪在产出剖面流温测试中的优越性。%This paper briefly introduces the working principle of the storage type well thermometer,Selectively analysed the application effects of the storage type well thermometer in production profile logging ,compared with the well temperature curve from the well temperature and pressure nipple, Expounded the superiority of the storage type well thermometer in the flow temperature of production profile.

  17. Processing and interpretation of data from the geophysical well-logging studies. Obrabotka i intergretatsiya materialov geofizicheskikh issledovanii skvazhin

    Energy Technology Data Exchange (ETDEWEB)

    Latyshova, M.G.; Tuzov, V.P.; Vendel' shtein, B.Yu.

    1975-01-01

    Main procedures of treatment and interpretation of results of contemporary complex of geophysical investigations of wells on deposits of petroleum and gas, mineral coals, ore and also non-metallic mineral raw material are stated. Physical bases and methods of geophysical interpretation of diagrams of methods of electric, magnetic, nuclear, acoustic, thermal, geochemical, and certain methods of checking for technical state of well are examined. Significant attention was devoted to complex geological interpretation of results of geophysical investigations of wells, application of geophysical materials for appraisal of parameters, used upon calculation of reserves of different useful minerals. Contemporary state of machine interpretation of diagrams of geophysical methods conformably to petroleum and gas industry was characterized.

  18. Pyritization effect on well logging parameters in Jurassic reservoirs within S-E Western Siberian oil fields

    Science.gov (United States)

    Janishevskii, A.; Ten, T.; Ezhova, A.

    2016-09-01

    Authigenic sulfide mineralization in hydrocarbon-saturated reservoirs distorts the electrical and density properties of rocks. The correlation between volumetric density, electro-conductive minerals and open porosity in 300 samples were determined. This fact made it possible to develop a nomograph in evaluating oil saturated reservoirs and could be applied in well geophysical survey data interpretation.

  19. Application of a new NMR well logging porosity/permeability calibration to the Arbuckle injection zone of the Wellington CO2 demonstration site

    Science.gov (United States)

    Mason, H. E.; Smith, M. M.; Hao, Y.; Carroll, S.

    2016-12-01

    Carbonate reservoirs hold significant potential for carbon capture and storage (CCS) projects. Target formations for carbon dioxide (CO2) storage must have suitable porosity and permeability properties to ensure adequate long term storage. Of these, permeability can be difficult to estimate in carbonate reservoirs due to the orders of magnitude differences in pore sizes, and the complex geometry of existing pore networks or those developed due to reactive CO2 acidified fluids. One of the primary methods for assessing porosity and permeability of reservoirs is down well nuclear magnetic resonance (NMR) logging tools. Our work has been focused on constraining new porosity/permeability relationships in carbonate rocks using micro X-ray computed tomography (µXRCT) to characterize the pore networks to inform on the observed NMR relaxation behavior. This effort has shown that standard NMR methodologies can produce permeability estimates for carbonate rocks that differ by several orders of magnitude from directly measured values. Our new calibrations have rectified these discrepancies by identifying and accounting for the main properties of these rocks that contribute the measured NMR relaxation properties. Properties such as mineralogy, Fe and Mn content, pore geometry, and pore network tortuosity all contribute to the relaxation behavior observed by NMR and are now accomodated in this new calibration procedure. This work has led to new understanding of the properties of these rock types that control the permeability measured by NMR well logging. In this presentation, we apply the results of a lab measured calibration of porosity and permeability to a high resolution NMR well log produced for the Arbucke injection zone of the Wellington CO2 demonstration sites. This application illustrates the applicability of this new calibration method for carbonate reservoirs and helps advance our understanding of the permeability and porosity relationships in these complex rock

  20. Study of Correlation of Logging Parameters Obtained from the Wells Drilled on Two Nearby Areas with the Same Geological Structure. An Example of Counties Russell and Ellis, Kansas State, USA

    Directory of Open Access Journals (Sweden)

    P. R. Shiryaev

    2016-12-01

    Full Text Available Based on the data shared by Kansas geological survey, the analysis of logging parameters from the wells located in nearby Counties Russell and Ellis located in the Kansas State, USA was performed. These counties have the similar geological structure. Data obtained in Kansas geological survey were processed to delete the gaps and other inconsistent readings. Then the correlation matrixes were calculated showing correlation between shallow, medium and deep logging in each well. Correlation matrixes demonstrated significant correlation between medium and deep logging, and medium and shallow logging because of similar geological structure. Ellis County is located at higher elevation than Russell County hence well top in Ellis County is at the higher elevation than well top in Russell County. We determined the depth shift, for which the maximum correlation between logging parameters in both wells (in Russell and Ellis Counties was observed. In addition, the correlation coefficients for the same logging parameters in two wells were received. The strongest correlation coefficient of up to 0.425 was obtained between medium logging in two wells. The results of study show that if the geological structures are similar the logging parameters obtained from the wells in these areas are also similar.

  1. Geophysical Logs, Aquifer Tests, and Water Levels in Wells in and Near the North Penn Area 7 Superfund Site, Upper Gwynedd Township, Montgomery County, Pennsylvania, 2002-2006

    Science.gov (United States)

    Senior, Lisa A.; Conger, Randall W.; Bird, Philip H.

    2008-01-01

    Ground water in the vicinity of several industrial facilities in Upper Gwynedd Township and Lansdale Borough, Montgomery County, Pa., is contaminated with several volatile organic compounds (VOCs). The 2-square-mile area was placed on the National Priorities List as the North Penn Area 7 Superfund Site by the U.S. Environmental Protection Agency (USEPA) in 1989. The U.S. Geological Survey (USGS) conducted geophysical logging, aquifer testing, water-level monitoring, and streamflow measurements in the vicinity of North Penn Area 7 from October 2002 through December 2006. This followed work that began in 2000 to assist the USEPA in developing an understanding of the hydrogeologic framework in the area as part of the USEPA Remedial Investigation. The study area is underlain by Triassic- and Jurassic-age sandstones, siltstones, and shales of the Lockatong Formation and the Brunswick Group. Regionally, these rocks strike northeast and dip to the northwest. The sequence of rocks form fractured-rock aquifers that act as a set of confined to semi-confined layered aquifers of differing permeabilities. The aquifers are recharged by precipitation and discharge to streams and wells. The Wissahickon Creek headwaters are less than 1 mile northeast of the study area. This stream flows southwest approximately parallel to strike and bisects North Penn Area 7. Ground water is pumped in the vicinity of North Penn Area 7 for industrial use and public supply. The USGS collected geophysical logs for 42 wells that ranged in depth from 40 to 477 ft. Aquifer-interval-isolation testing was done in 17 of the 42 wells, for a total of 122 zones tested. A multiple-well aquifer test was conducted by monitoring the response of 14 wells to pumping and shutdown of a 600-ft deep production well in November-December 2004. In addition, water levels were monitored continuously in four wells in the area from October 2002 through September 2006, and streamflow was measured quarterly at two sites on

  2. Tangafric: a software for the estimation of textural and hydraulic properties in shallow aquifers from well logs in Senegal and Guinea

    Science.gov (United States)

    Fussi, Fabio; Bonomi, Tullia; Fava, Francesco; Hamidou, Barry; Hamidou Khane, Cheikh; Faye, Gayane; Wade, Souleye; Colombo, Roberto

    2014-05-01

    data codification, quantification and processing, connected to a hydraulic conductivity value associated to each primary lithology. Results Starting from the database of borehole logs available at national level in Senegal and Guinea (about 1400 borehole logs in Senegal and 800 in Guinea, with 20000 definitions), their structure and information have been compared and a new common database has been set up; it has a consistent structure with the structure of existing national database and data can be easily imported and exported. From this joint, the new software TANGAFRIC has been created with different purposes: -to organize in the same way wells data, since the two countries have different administrative divisions (ID code, name of village, district, regions, coordinates); -to add new wells data, not existing in the previous databases; -to codify the stratigraphic layer of each well logs with a 5-digit alphanumeric codes, using a list of categories describing texture, status and color or each layers, identified from the most recurrent lithological classes and attributes; -to attribute a specific value of hydraulic conductivity to each texture, from well data, field pumping test, bibliographic review. TANGAFRIC includes one module for data input and a second module to process the data, and extract specific parameters concerning mean texture, hydraulic conductivity and transmissivity in selected depth ranges. This is made possible by attributing a weight to the digits of the code for textures. The program calculates the percentage of the chosen lithology, as related to each individual layer, and also a weighted average of hydraulic conductivity. It has been possible to produce maps showing the distribution of main texture classes, thickness of saturated unconsolidated sediments and expected transmissivity. Furthermore, these parameters have been used to estimate the suitability for manual drilling under the hydrogeological coniditions described in each borehole logs.

  3. Logs of wells and boreholes drilled during hydrogeologic studies at Lawrence Livermore National Laboratory Site 300, January 1, 1982--June 30, 1988: January 1, 1982 through June 30, 1988

    Energy Technology Data Exchange (ETDEWEB)

    Toney, K.C.; Crow, N.B.

    1988-01-01

    We present the hydrogeologic well logs for monitor wells and exploratory boreholes drilled at Lawrence Livermore National Laboratory (LLNL) Site 300 between the beginning of environmental investigations in June 1982 and the end of June 1988. These wells and boreholes were drilled as part of studies made to determine the horizontal and vertical distribution of volatile organic compounds (VOCs), high explosive (HE) compounds, and tritium in soil, rock, and ground water at Site 300. The well logs for 293 installations comprise the bulk of this report. We have prepared summaries of Site 300 geology and project history that provide a context for the well logs. Many of the logs in this report have also been published in previous topical reports, but they are nevertheless included in order to make this report a complete record of the wells and boreholes drilled prior to July 1988. A commercially available computer program, LOGGER has been used since late 1985 to generate these logs. This report presents details of the software programs and the hardware used. We are presently completing a project to devise a computer-aided design (CAD) system to produce hydrogeologic cross sections and fence diagrams, utilizing the digitized form of these logs. We find that our system produces publication-quality well and exploratory borehole logs at a lower cost than that of logs drafted by traditional methods.

  4. Dose estimative in operators during petroleum wells logging with nuclear wireless probes through computer modelling; Estimativa da dose em operadores durante procedimentos de perfilagem de pocos de petroleo com sondas wireless nucleares atraves de modelagem computacional

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Edmilson Monteiro de; Silva, Ademir Xavier da; Lopes, Ricardo T., E-mail: emonteiro@nuclear.ufrj.b, E-mail: ademir@nuclear.ufrj.b, E-mail: ricardo@lin.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Lima, Inaya C.B., E-mail: inaya@lin.ufrj.b [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Programa de Engenharia Nuclear; Instituto Politecnico do Rio de Janeiro (IPRJ/UERJ), Nova Friburgo, RJ (Brazil); Correa, Samanda Cristine Arruda, E-mail: scorrea@cnen.gov.b [Comissao Nacional de Energia Nuclear (DIAPI/CGMI/CNEN), Rio de Janeiro, RJ (Brazil); Rocha, Paula L.F., E-mail: ferrucio@acd.ufrj.b [Universidade Federal do Rio de Janeiro (UFRJ)., RJ (Brazil). Dept. de Geologia

    2011-10-26

    This paper evaluates the absorbed dose and the effective dose on operators during the petroleum well logging with nuclear wireless that uses gamma radiation sources. To obtain the data, a typical scenery of a logging procedure will be simulated with MCNPX Monte Carlo code. The simulated logging probe was the Density Gamma Probe - TRISOND produced by Robertson Geolloging. The absorbed dose values were estimated through the anthropomorphic simulator in male voxel MAX. The effective dose values were obtained using the ICRP 103

  5. Geophysical logs and water-quality data collected for boreholes Kimama-1A and -1B, and a Kimama water supply well near Kimama, southern Idaho

    Science.gov (United States)

    Twining, Brian V.; Bartholomay, Roy C.

    2011-01-01

    In September 2010, a research consortium led by scientists from Utah State University began drilling the first of three continuously cored boreholes on the Snake River Plain in southern Idaho. The goals of this effort, the Snake River Scientific Drilling Project, are to study the interaction between the Earth's crust and mantle, to identify potential geothermal energy sources, and to track the evolution of the Yellowstone hotspot on the Snake River Plain. The first borehole, located near Kimama, Idaho, is about 50 miles southwest of the U.S. Department of Energy's Idaho National Laboratory. Because geohydrologic data are scarce for that area of the central Snake River Plain, the Kimama borehole, completed in January 2011, provided a unique opportunity to collect geophysical and water-chemistry data from the eastern Snake River Plain aquifer system, downgradient of the laboratory. Therefore, in conjunction with the Snake River Scientific Drilling Project, scientists from the U.S. Geological Survey's Idaho National Laboratory Project Office conducted geophysical logging and collected water samples at the Kimama site. Wireline geophysical logs were collected for the diverging borehole, Kimama-1A and -1B, from land surface to 976 and 2,498 feet below land surface (BLS), respectively. Water samples were collected from Kimama-1A at depths near 460 and 830 feet BLS, and from the Kimama Water Supply (KWS) well located about 75 feet away. Geophysical log data included a composite of natural gamma, neutron, gamma-gamma dual density, and gyroscopic analysis for boreholes Kimama-1A and -1B. Geophysical logs depicted eight sediment layers (excluding surficial sediment) ranging from 4 to 60 feet in thickness. About 155 individual basalt flows were identified, ranging from less than 3 feet to more than 175 feet in thickness (averaging 15 feet) for borehole Kimama-1B (0 to 2,498 feet BLS). Sediment and basalt contacts were selected based on geophysical traces and were confirmed

  6. Characterizing the regional pattern and temporal change of groundwater levels by analyses of a well log data set

    Institute of Scientific and Technical Information of China (English)

    Mahmuda PARVIN; Naoyuki TADAKUMA; Hisafumi ASAUE; Katsuaki KOIKE

    2011-01-01

    Preservation of the amount and quality of groundwater resources is an important issue around the world.Changes in groundwater levels need to be monitored in efforts to preserve groundwater.This study investigates suitable methods to characterize changes in the groundwater level and determine the factors involved.The area of Kumamoto,a city in central Kyushu,southwest Japan,was selected to demonstrate the usefulness of the methods because this area is one of the richest in Japan in terms of groundwater resources and takes all its water from groundwater.Data of the groundwater level recorded at 69 wells from 1979 to 2007 were used in geostatistical and correlogram analyses.First,strong correlation between the topography and groundwater level was identified.Incorporating this correlation into spatial modeling of the groundwater level,co-kriging was demonstrated to be more accurate than ordinary kriging.The co-kriging results clarified the hydraulic characteristics of the Kumamoto area; the patterns of shallow and deep groundwater levels were agreeable generally,and the general trends of their annual average levels were similar regardless of precipitation.Another important feature was that the correlograms for the precipitation amount and groundwater level had a constant shape and changed smoothly with a change in lag time regardless of the precipitation only in the area of Togawa lava.These characteristics are probably due to the connections between shallow and deep aquifers and the high permeability of Togawa lava.

  7. Geophysical Well Logs Applied to Geothermal Resource Evaluation Application des diagraphies à l'évaluation des ressources géothermiques

    Directory of Open Access Journals (Sweden)

    Fertl W. H.

    2006-11-01

    Full Text Available Well logging in the petroleum industry has been developed over five decades into a mature industry, whereas geothermal well logging is a relatively new enterprise. Fundamental differences also occur in the geologic environments and key objectives of both logging applications. Geothermal reservoirs are frequently in fractured igneous and metamorphic rocks, which contain hot water or stem at temperature exceeding 150°C. The discussion focuses on present day logging technology, geologic and reservoir engineering objectives, and qualitive and quantitative formation interpretation techniques for geothermal resource evaluation. Specific field case studies illustrate the interpretive state-of-the-art, including examples from the Geysers dry steam field in the Imperial Valley of California, hot water fields in California, Nevada, and Idaho, and the LASL Hot Dry Rock test project in the Valles Caldera of New Mexico. Les diagraphies dans les forages pétroliers ont atteint leur maturité, alors que le contrôle diagraphique des sondages géothermiques est une entreprise relativement nouvelle. Des différences fondamentales apparaissent aussi dans les environnements géologiques et dans les objectifs clés des deux types d'applications des diagraphies. Les réservoirs géothermiques se situent souvent dans les roches ignées ou métamorphiques fracturées qui contiennent de l'eau chaude ou de la vapeur à des températures dépassant 150 °C. L'exposé sera concentré sur les techniques actuelles d'enregistrements, les objectifs géologiques et liés à l'exploitation des réserves et sur les techniques qualitatives et quantitatives d'interprétation des formations pour l'évaluation des ressources géothermiques. Quelques cas particuliers illustrent l'état actuel des techniques d'interprétation avec des exemples pris dans le champ de vapeur sèche des geysers dans Imperial Valley de Californie, des champs d'eau chaude en Californie, Nevada et Idaho et

  8. The thermal regime in the resurgent dome of Long Valley Caldera, California: Inferences from precision temperature logs in deep wells

    Science.gov (United States)

    Hurwitz, S.; Farrar, C.D.; Williams, C.F.

    2010-01-01

    Long Valley Caldera in eastern California formed 0.76Ma ago in a cataclysmic eruption that resulted in the deposition of 600km3 of Bishop Tuff. The total current heat flow from the caldera floor is estimated to be ~290MW, and a geothermal power plant in Casa Diablo on the flanks of the resurgent dome (RD) generates ~40MWe. The RD in the center of the caldera was uplifted by ~80cm between 1980 and 1999 and was explained by most models as a response to magma intrusion into the shallow crust. This unrest has led to extensive research on geothermal resources and volcanic hazards in the caldera. Here we present results from precise, high-resolution, temperature-depth profiles in five deep boreholes (327-1,158m) on the RD to assess its thermal state, and more specifically 1) to provide bounds on the advective heat transport as a guide for future geothermal exploration, 2) to provide constraints on the occurrence of magma at shallow crustal depths, and 3) to provide a baseline for future transient thermal phenomena in response to large earthquakes, volcanic activity, or geothermal production. The temperature profiles display substantial non-linearity within each profile and variability between the different profiles. All profiles display significant temperature reversals with depth and temperature gradients temperature in the individual boreholes ranges between 124.7??C and 129.5??C and bottom hole temperatures range between 99.4??C and 129.5??C. The high-temperature units in the three Fumarole Valley boreholes are at the approximate same elevation as the high-temperature unit in borehole M-1 in Casa Diablo indicating lateral or sub-lateral hydrothermal flow through the resurgent dome. Small differences in temperature between measurements in consecutive years in three of the wells suggest slow cooling of the shallow hydrothermal flow system. By matching theoretical curves to segments of the measured temperature profiles, we calculate horizontal groundwater velocities in

  9. 油页岩测井识别技术及应用%Identification Technology and It's Application of Well-Logging About Oil Shale

    Institute of Scientific and Technical Information of China (English)

    朱建伟; 赵刚; 刘博; 郭巍; 成俊

    2012-01-01

    The traditional technology of exploration and recognition oil shale mainly rely on geological survey on the field, core and sample testing and analyzing. On the basis of analysis and research on geological survey on the field, the description of core, log and test data analysis, and comprehensive research, the paper proposed a qualificative and quantitative technology of recognizing oil shale effectively using well-logging data, and applied them in the Songliao basin. Properties of oil shale is high resistivity, high gamma, high sonic and low density in the well longing data. Resistivity data is the best about the correlation between oil yield of oil shale and well logging parameters. The one member linear regression relationship between oil yield of oil shale and the well logging data is better than that of two members and three members. Not only oil yield but also total organic carbon can be calculated using ΔlgR technology. The calculated results show that the deviation between calculated oil yield and testing oil yield is relatively small using the linear relationship between oil yield of oil shale and the resistivity well-logging data and ΔlgR technology.%传统的油页岩资源勘查与识别主要依靠野外地质调查、钻井取心及测试分析.在对松辽盆地野外地质勘查、岩心描述、测井和测试资料分析及综合研究的基础上,提出了油页岩定性和定量测井识别技术,并在松辽盆地进行了应用.在测井响应上,油页岩表现为高电阻率、高自然伽马、高声波时差和低密度特征;油页岩含油率与测井响应的一元线性回归关系好于二元线性回归关系和三元线性回归关系;油页岩的含油率与电阻率的相关性最好.利用△lgR技术不但可以求得油页岩的含油率,还可以求得总有机碳含量.试算结果表明,利用油页岩含油率与电阻率的线性关系和△lgR技术计算出的油页岩含油率与实测含油率误差相对较小.

  10. 3D Reservoir Modeling of Semutang Gas Field: A lonely Gas field in Chittagong-Tripura Fold Belt, with Integrated Well Log, 2D Seismic Reflectivity and Attributes.

    Science.gov (United States)

    Salehin, Z.; Woobaidullah, A. S. M.; Snigdha, S. S.

    2015-12-01

    Bengal Basin with its prolific gas rich province provides needed energy to Bangladesh. Present energy situation demands more Hydrocarbon explorations. Only 'Semutang' is discovered in the high amplitude structures, where rest of are in the gentle to moderate structures of western part of Chittagong-Tripura Fold Belt. But it has some major thrust faults which have strongly breached the reservoir zone. The major objectives of this research are interpretation of gas horizons and faults, then to perform velocity model, structural and property modeling to obtain reservoir properties. It is needed to properly identify the faults and reservoir heterogeneities. 3D modeling is widely used to reveal the subsurface structure in faulted zone where planning and development drilling is major challenge. Thirteen 2D seismic and six well logs have been used to identify six gas bearing horizons and a network of faults and to map the structure at reservoir level. Variance attributes were used to identify faults. Velocity model is performed for domain conversion. Synthetics were prepared from two wells where sonic and density logs are available. Well to seismic tie at reservoir zone shows good match with Direct Hydrocarbon Indicator on seismic section. Vsh, porosity, water saturation and permeability have been calculated and various cross plots among porosity logs have been shown. Structural modeling is used to make zone and layering accordance with minimum sand thickness. Fault model shows the possible fault network, those liable for several dry wells. Facies model have been constrained with Sequential Indicator Simulation method to show the facies distribution along the depth surfaces. Petrophysical models have been prepared with Sequential Gaussian Simulation to estimate petrophysical parameters away from the existing wells to other parts of the field and to observe heterogeneities in reservoir. Average porosity map for each gas zone were constructed. The outcomes of the research

  11. Field project to obtain pressure core, wireline log, and production test data for evaluation of CO/sub 2/ flooding potential. Conoco MCA unit well No. 358, Maljamar Field, Lea County, New Mexico. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Swift, T.E.; Kumar, R.M.; Marlow, R.E.; Wilhelm, M.H.

    1982-08-01

    Field operations, which were conducted as a cooperative effort between Conoco and Gruy Federal, began on January 16, 1980 when the well was spudded. The well was drilled to 3692 feet, and 18 cores recovered in 18 core-barrel runs (144 feet). Upon completion of the coring phase, the hole was drilled to a total depth of 4150 feet and a complete suite of geophysical logs was run. Logging was then followed by completion and testing by Concoco. Core porosities agreed well with computed log porosities. Core water saturation and computed log porosities agree fairly well from 3692 to 3712 feet, poorly from 3712 to 3820 feet and in a general way from 4035 to 4107 feet. Computer log analysis techniques did not improve the agreement of log versus core derived water saturations. However, both core and log analysis indicated the ninth zone had the highest residual hydrocarbon saturations. Residual oil saturation were 259 STB/acre-ft for the 4035 - 4055 feet interval, and 150 STB/acre-ft for the 3692 - 3718 feet interval. Nine BOPD was produced from the 4035 - 4055 feet interval and no oil was produced from 3692 to 3718 feet interval, qualitatively confirming the relative oil saturations. The low oil production in the zone from 4022 to 4055 and the lack of production from 3692 to 3718 feet indicated the zone to be at or near residual waterflood conditions as determined by log analysis. 68 figures, 11 tables.

  12. The Tunisian Jurassic aquifer in the North African Sahara aquifer system: information derived from two-dimensional seismic reflection and well logs

    Science.gov (United States)

    Ben Lasmar, Rafika; Guellala, Rihab; Garrach, Mohamed; Mahroug, Ali; Sarsar Naouali, Benen; Inoubli, Mohamed Hédi

    2017-07-01

    Southern Tunisia is an arid area where socio-economic activities are dependent on groundwater resources. The presented study aims to better characterize the Jurassic aquifer based on geological and geophysical data, with a view to develop a rational exploitation program. Well logs are used to precisely determine the position and composition of the known Jurassic aquifer layers and to identify others able to produce good quality water. The logs show that limestones, sandstones and dolomites of the Krachoua, Techout and Foum Tataouine formations are the main Jurassic aquifers. Sixty-eight seismic-reflection sections are integrated within this study. The interpolation between the interpreted sections leads to the construction of isochronous isopach maps and geoseismic sections, and their analysis finds that compressive and extensive tectonic deformations have influenced the Jurassic aquifer geometry. The Hercynian orogeny phase manifestation is remarkable in that there are several stratigraphic gaps in the Jurassic sequence. The E-W, NW-SE, and NNW-SSE accidents, reactivated in normal faults since the Permian to Lower Cretaceous epochs, have generated the structures found in the Jurassic series, such as subsided and raised blocks. Their syn-sedimentary activity has controlled the thickness and facies of these series. The Cretaceous, Tortonian and Post-Villafranchian compressions are responsible for the Jurassic-deposits folding in some localities. The highlighted tectonic and sedimentary events have an important impact on the Jurassic aquifer function by favoring the Jurassic aquifer interconnections and their connections with the Triassic and Cretaceous permeable series.

  13. DETAILED STUDY ON THE WELL LOGGING INTERPRETATION MODELS OF POROSITY PARAMETER%孔隙度参数测井解释模型细化研究

    Institute of Scientific and Technical Information of China (English)

    赵忠波

    2012-01-01

    基于大庆油田萨中开发区葡一组沉积特征,充分利用测井资料和密闭取心井资料,采用多元线性回归分析等数学方法,建立了三角洲内前缘相、泛滥平原相曲流河、分流平原相的孔隙度模型.模型精度达到生产井测井解释标准及地质储量规范的计算要求,使三维地质建模能够更加精确地描述葡一组储层非均质性,为进一步挖掘厚油层内部剩余油奠定了基础.%On the basis of the sedimentary characteristics of PI Formation in Sazhong development block of Daqing Oilfield, and making full use of the data of well logging and closed coring well, the porosity models of inner front facies of the delta, meandering facies of flooded plain facies and distributary plain facies are established by means of the mathmetical methods such as multiple regression analysis and so on. The models' precisions are all up to the standard of production well logging interpretation and the calculation requirements of geological reserves regulations, thus the 3D geological modeling can more accurately characterize the heterogeneity of P1 Formation reservoirs, and furthermore it has laid foundation for the further tapping of inner remained oil in those thick reservoirs.

  14. Sample descriptions and geophysical logs for cored well BP-3-USGS, Great Sand Dunes National Park and Preserve, Alamosa County, Colorado

    Science.gov (United States)

    Grauch, V.J.S.; Skipp, Gary L.; Thomas, Jonathan V.; Davis, Joshua K.; Benson, Mary Ellen

    2015-01-01

    The BP-3-USGS well was drilled at the southwestern corner of Great Sand Dunes National Park in the San Luis Valley, south-central Colorado, 68 feet (ft, 20.7 meters [m]) southwest of the National Park Service’s boundary-piezometer (BP) well 3. BP-3-USGS is located at latitude 37°43ʹ18.06ʺN. and longitude 105°43ʹ39.30ʺW., at an elevation of 7,549 ft (2,301 m). The well was drilled through poorly consolidated sediments to a depth of 326 ft (99.4 m) in September 2009. Water began flowing from the well after penetrating a clay-rich layer that was first intercepted at a depth of 119 ft (36.3 m). The base of this layer, at an elevation of 7,415 ft (2,260 m) above sea level, likely marks the top of a regional confined aquifer recognized throughout much of the San Luis Valley. Approximately 69 ft (21 m) of core was recovered (about 21 percent), almost exclusively from clay-rich zones. Coarser grained fractions were collected from mud extruded from the core barrel or captured from upwelling drilling fluids. Natural gamma-ray, full waveform sonic, density, neutron, resistivity, spontaneous potential, and induction logs were acquired. The well is now plugged and abandoned.

  15. Yucatan Subsurface Stratigraphy from Geophysical Data, Well Logs and Core Analyses in the Chicxulub Impact Crater and Implications for Target Heterogeneities

    Science.gov (United States)

    Canales, I.; Fucugauchi, J. U.; Perez-Cruz, L. L.; Camargo, A. Z.; Perez-Cruz, G.

    2011-12-01

    Asymmetries in the geophysical signature of Chicxulub crater are being evaluated to investigate on effects of impact angle and trajectory and pre-existing target structural controls for final crater form. Early studies interpreted asymmetries in the gravity anomaly in the offshore sector to propose oblique either northwest- and northeast-directed trajectories. An oblique impact was correlated to the global ejecta distribution and enhanced environmental disturbance. In contrast, recent studies using marine seismic data and computer modeling have shown that crater asymmetries correlate with pre-existing undulations of the Cretaceous continental shelf, suggesting a structural control of target heterogeneities. Documentation of Yucatan subsurface stratigraphy has been limited by lack of outcrops of pre-Paleogene rocks. The extensive cover of platform carbonate rocks has not been affected by faulting or deformation and with no rivers cutting the carbonates, information comes mainly from the drilling programs and geophysical surveys. Here we revisit the subsurface stratigraphy in the crater area from the well log data and cores retrieved in the drilling projects and marine seismic reflection profiles. Other source of information being exploited comes from the impact breccias, which contain a sampling of disrupted target sequences, including crystalline basement and Mesozoic sediments. We analyze gravity and seismic data from the various exploration surveys, including multiple Pemex profiles in the platform and the Chicxulub experiments. Analyses of well log data and seismic profiles identify contacts for Lower Cretaceous, Cretaceous/Jurassic and K/Pg boundaries. Results show that the Cretaceous continental shelf was shallower on the south and southwest than on the east, with emerged areas in Quintana Roo and Belize. Mesozoic and upper Paleozoic sediments show variable thickness, possibly reflecting the crystalline basement regional structure. Paleozoic and Precambrian

  16. Recognition of Milankovitch cycles in the stratigraphic record:application of the CWT and the FFT to well-log data

    Institute of Scientific and Technical Information of China (English)

    YU Ji-feng; SUI Feng-gui; LI Zeng-xue; LIU Hua; WANG Yu-lin

    2008-01-01

    The authors applied a the combination of Continuous Wavelet Transform (CWT) and Fast Fourier Transform (FFF)methods to gamma ray well-log data from the Q3, G1 and D2 wells. This high-resolution stratigraphic study was based on Milankovitch's orbital cycle theory. It was found that the CWT scale factors, 'a,' of 12, 24 and 60 match the ratios of the periodicities of precession, obliquity and eccentricity very well. Nine intervals of the Permo-carboniferous strata were recognized to have Milankovitch cycles in them. For example, section A of well Q3 has 29 precession cycles, 15 obliquity cycles and 7 short eccentricity cycles. The wavelengths are 2.7, 4.4 and 7.8 m for precession, obliquity and eccentricity, respectively. Important geological parameters such as the stratigraphic completeness and the accumulation rate were also estimated. These results provide basic information for further cyclostratigraphic correlation studies in the area. They are of great significance for the study of ancient and future climate change.

  17. 辽河坳陷古近系页岩油气测井识别%Liaohe Depression Paleogene Shale Oil and Gas Well Logging Identification

    Institute of Scientific and Technical Information of China (English)

    陈康; 张金川; 唐玄

    2016-01-01

    Liaohe depression Paleogene shale which is a focused strata in shale oil and gas exploration develop extensively .Well logging technology is an economic and effective identification method of shale oil and gas in this area .Paleogene shale logging response characteristics and mechanism were studied , and it is concluded that organ-ic matter increase acoustic time (AC), hydrocarbon increase resistivity (Rt).Based on ΔlgR method, Rt curve and AC curve are reverse superimposed .According to the separation forms of superimposed curves , organic matter and hydrocarbon anomaly response are indicated , and shale oil and gas can be identified qualitatively .The separa-tion forms of Rt and AC curves of shale oil and gas effective layers are divided into three types and geological fea -tures of these types have certain regularity by statistics .According to the classification of superimposed curves , the effectivity of shale oil and gas layers can be semi-quantitatively evaluated .The shale oil and gas logging identifica-tion method is quick and effective which has practical promotion value .%辽河坳陷古近系广泛发育泥页岩层,是页岩油气勘探的热点层系,利用测井技术识别该地区页岩油气经济有效。研究了古近系泥页岩段测井响应特征,并对页岩储层测井响应机理进行剖析,认为有机质增多声波时差( AC)增大,烃类增多电阻率( Rt)变大。在ΔlgR方法基础上,将Rt和AC曲线反向叠合,依据叠合曲线的幅度差指示有机质和烃类的异常响应,进而定性地识别页岩油气。将页岩油气有效层的Rt与AC曲线的幅度差形态分成三类统计地质特征,发现各类形态具有一定的地质特征规律,可根据形态分类半定量地对页岩油气有利性进行评价。该页岩油气测井识别方法快捷有效具有应用推广价值。

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

    Science.gov (United States)

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

    2010-01-01

    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

  19. 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.

    2010-02-12

    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

  20. Borehole geophysical logging and aquifer-isolation tests conducted in well MG-1693 at North Penn Area 5 Superfund Site near Colmar, Montgomery County, Pennsylvania

    Science.gov (United States)

    Bird, Philip H.

    2006-01-01

    Borehole geophysical logging and aquifer-isolation (packer) tests were conducted in well MG-1693 (NP-87) at the North Penn Area 5 Superfund Site near Colmar, Montgomery County, Pa. Objectives of the study were to identify the depth and yield of water-bearing zones, occurrence of vertical borehole flow, and effects of pumping on water levels in nearby wells. Caliper, natural-gamma, single-point-resistance, fluid-temperature, fluid-resistivity, heatpulse-flowmeter, and borehole-video logs were collected. Vertical borehole-fluid movement direction and rate were measured under nonpumping conditions. The suite of logs was used to locate water-bearing fractures, determine zones of vertical borehole-fluid movement, and select depths to set packers. Aquifer-isolation tests were conducted to sample discrete intervals and to determine specific capacities of water-bearing zones and effects of pumping individual zones on water levels in two nearby monitor wells. Specific capacities of isolated zones during aquifer-isolation tests ranged from 0.03 to 3.09 (gal/min)/ft (gallons per minute per foot). Fractures identified by borehole geophysical methods as water-producing or water-receiving zones produced water when isolated and pumped. Water enters the borehole primarily through high-angle fractures at 416 to 435 ft bls (feet below land surface) and 129 to 136 ft bls. Water exits the borehole through a high-angle fracture at 104 to 107 ft bls, a broken casing joint at 82 ft bls, and sometimes as artesian flow through the top of the well. Thirteen intervals were selected for aquifer-isolation testing, using a straddle-packer assembly. The specific capacity of interval 1 was 2.09 (gal/min)/ft. The specific capacities of intervals 2, 3, and 4 were similar: 0.27, 0.30, and 0.29 (gal/min)/ft,respectively. The specific capacities of intervals 5, 6, 7, 8, and 10 were similar: 0.03, 0.04, 0.09, 0.09, and 0.04 (gal/min)/ft,respectively. Intervals 9, 11, and 12 each showed a strong

  1. 测井技术在春光油田老井复查中的应用%Application of Logging in old wells reexamination in Chunguang Oilfield

    Institute of Scientific and Technical Information of China (English)

    林科

    2015-01-01

    为了实现春光油田持续生产的需要,对春光地区老井进行二次处理解释和精细评价,寻找新储量。本文主要对春光油田储层测井响应特征,四性关系研究进行了分析,运用老井资料开展复查工作,并取得了良好的效果。%Secondary processing and interpretation and fine evaluation on old wells in Chunguang Oilfield are carried out to find new reserves and to achieve long time production in this oilfield.This paper presents the response characteristics of the logging and relationship among lithology,physical property,electric property and hydrocarbon-bearing of reservoirs.The reexamination has achieved good results by use of old well data.

  2. 利用测井曲线进行地层精细划分与对比%Fine Stratigraphic Classification and Correlation by Using Well Logs

    Institute of Scientific and Technical Information of China (English)

    孙健; 袁子龙; 吴丙禹

    2014-01-01

    Formation division and correlations of strata is of great importance for the lithologic reservoir exploration because it will directly affect the accuracy of the cognition of individual sand body and lithologic reservoir forecast and oil-gas distribution. Duo to the limitation of limited the coring well and data, when the oil field development comes to its Medium-late Stage, it will take advantage to use well logging data to divide and compare the formation. Only when we divide the formation according to geology regularity and build the correct isochronous correlation, find the reasonable first well and the right comparison way can we build the reasonable geology frame to guide the proper development of oil-gas reservoir.%地层划分与对比直接影响单砂体识别的准确性和预测油藏及油气的分布规律,所以地层划分与对比对勘探开发及岩性油藏探区具有重要的意义。随着油田开发进入到了中后期,开发节点的增加受到取芯井及其他井资料的限制,利用测井曲线进行地层的划分与对比占有绝对的优势。根据地质规律划分地层并建立正确的等时对比,确定合理起始井以及正确的对比路线,建立合理的地质框架对油气田的合理开发有重要指导作用。

  3. 新世纪第二个五年测井技术的若干进展%Progress of well logging techniques during the second five years of the new millennium

    Institute of Scientific and Technical Information of China (English)

    张元中

    2012-01-01

    本文对新世纪第二个五年测井技术的进展进行评述,分析电缆测井、随钻测井、地层测试等井筒探测技术的发展状况,介绍了一些最新的测井仪器和测井方法,重点讨论了测井技术在地层各向异性探测方向的进展.此外对井下永久传感器网络技术,噪声测井,重力测井,过钻头测井的进展进也行了介绍.%The progress of the well logging techniques in the second five years of the new millennium is reviewed in the paper. The developing status of the borehole exploration techniques such as wireline logging, MWD /LWD and formation testing are analyzed, and some of the latest logging tools and the logging methods are presented. The developments in the prospecting of the formation anisotropy are mainly discussed. Otherwise the downhole permanent sensor network, noise logging, gravity logging and through bit logging are also introduced.

  4. 基于希尔伯特变换的测井曲线高分辨率处理方法%High resolution processing method for well logs based on Hilbert transformation

    Institute of Scientific and Technical Information of China (English)

    张涛; 林承焰; 张宪国; 于景锋; 张守秀; 方涛

    2012-01-01

    探索将希尔伯特变换应用于测井资料高分辨率处理与解释的方法.首先利用希尔伯特变换将测并曲线分解成二维信号,然后利用变换结果求测井曲线的瞬时属性参数(瞬时振幅、瞬时相位和瞬时频率),再利用岩心等地质资料和先验地质认识对测井属性曲线进行检验和标定,并将其用于非取心段的薄层测井识别.将所提方法应用于大港滩海张东地区沙河街组三角洲前缘测井评价,发现瞬时相位和瞬时频率测井曲线能够对原测井曲线上的微小变化产生放大效应,提高薄层界面识别精度.在吉林红岗油气田的三角洲相储层构型研究中,利用岩心对高分辨率处理后的曲线进行标定,验证了处理结果的合理性.%Hilbert transformation was used in resolution-enhancement process and interpretation of well logs. Well log was decomposed into 2D signals with Hilbert transformation and then the instance attributes of well logs including instance amplitude, instance phase and instance frequency were calculated from the 2D signals. The prior geologic knowledge from drilling cores and other sources were employed to calculate the new instance attributes logs and to calibrate the calculated logs. The calculated attribute logs were subsequently used in thin layer interpretation where drilling cores are unavailable. This method was used in logging-based reservoir evaluation of delta front strata in Shahejie formation, Zhangdong shallow sea area, Dagang Oilfield. It is found that the instance phase and instance frequency of well logs can enhance the resolution of well logs to recognize thin layer reservoirs. These attributes can magnify the fine changes on original well logs. The results of this process calibrated by drilling cores are proved to be correct in the reservoir architecture study for delta reservoir of Honggang Oil & Gas Field.

  5. WELL LOGGING EVALUATION OF MARINE HYDROCARBON SOURCE ROCK IN TAZHONG AREA%塔中地区海相烃源岩测井评价

    Institute of Scientific and Technical Information of China (English)

    雷涛; 周文; 邓虎成; 赵安坤; 杨艺; 熊川

    2011-01-01

    To the low organic abundance and strong heterogeneity of the marine hydrocarbon source rock, this paper analyzes the well logging response characteristics of the marine hydrocarbon source rock in Tazhong area, and builds the plate for quantitative identification of Ordovician source rock in Tazhong area and the classification and identification model for marine source rock in the studied area. In the evaluation of organic matter abundance, the elastic parameters of hydrocarbon source rock, the ratio of uranium and thorium content, the difference of natural gamma, and the resistivity in Tazhong area are used as the input layers, and a BP neural network model based on the genetic algorithm is built. Practice shows that the TOC value predicated by this method is as accurate and reliable as the rock sample analysis result, providing the basis for the evaluation of effective hydrocarbon source rock.%针对海相烃源岩具有有机质丰度低和非均质性强的特点,分析了塔中地区海相烃源岩的测井响应特征,建立了塔中奥陶系烃源岩定量识别的图版及适合研究区海相烃源岩的分类识别模型.在有机质丰度评价方面,利用塔中地区烃源岩弹性参数、铀钍含量比、自然伽马的差值及电阻率作为输入层,建立了基于遗传算法的BP神经网络模型.实践表明,采用该方法预测的TOC值与岩石样品分析结果同样精确可靠,为评价有效烃源岩提供了依据.

  6. 地层评价与测井技术新进展——第51届SPWLA年会综述%Advances in Formation Evaluation and Well Logging Technology ——An Overview of the SPWLA 51st Annual Logging Symposium

    Institute of Scientific and Technical Information of China (English)

    安涛; 齐宝权; 高秋涛

    2011-01-01

    以第51届岩石物理学家和测井分析家协会(SPWlA)年会90余篇交流论文与产品展示内容为基础,通过归纳分析,对近1年来岩石物理与基础理论研究、测井新仪器与新方法研发、复杂油气藏及非常规油气藏综合评价技术等领域的最新进展进行了介绍与总结.在此基础上对测井方法、测井仪器、测井评价的国际发展趋势以及与国内的差距进行了分析讨论.%More than 90 technical papers and products show on well logging and formation evaluation during the SPWLA 51st annual logging symposium provide the base for tracing the latest advancement and finding the difference. The advances include the research about petrophysics and basic theory, logging tools and new methods, comprehensive evaluation on complex reservoirs and unconventional reservoirs. Then further discussion about the trend of international development on log methods, logging tools and log evaluations is presented and difference between home and abroad is the focus question.

  7. Ground Surface Power Supply Mode for the Deep -well Motor in Oil -well Logging Devices%油田测井装置深井电机地面供电方式的研究

    Institute of Scientific and Technical Information of China (English)

    彭其泽; 张全柱

    2011-01-01

    Power supply modes for driving hydraulic pump motor at the oil - well logging device were discussed. And advantages and disadvantages of six power supply modes were analyzed and compared with each other. A most promising motor power supply mode was then put forward. This mode has overcome disadvantages existed in traditional oil - well logging power supply method, I. E. , the transitional "voltage regulator along with transformer" method. The proposed power supply mode has advantages of small volume,light weight,convenient voltage regulation,small starting voltage,fast transient response,and high intelligence degree. This power supply is composed of several ICBT power transforming units,and has realized the transformation from single - phase low voltage of AC110V to dual -phase middle voltage of AC600 ~ AC1200V after multiple AC/DC/AC - AC/DC/AC voltage transform links.%针对油田测井装置的驱动液压泵电机的供电方式进行了研究,比较分析了6种供电方式的优缺点,提出一种最有应用前途的电机供电方式.该供电方式克服了传统的调压器加变压器的油田测井电源方式的诸多缺点,具有体积小、重量轻、电压调节方便、起动电流小、动态响应快和智能化程度高等优点.该电源由多个IGBT功率变换单元组成,经过AC/DC/AC—AC/DC/AC多个电压变换环节,实现从单相AC 110 V低压至双相AC600~AC 1 200V中压的变换.

  8. 基于压缩感知的声波测井曲线分辨率提高方法研究%Method of Improving Acoustic Well Logging Curve Resolution Based on Compressed Sensing

    Institute of Scientific and Technical Information of China (English)

    蒋彬

    2015-01-01

    测井曲线高分辨率处理是提高薄层测井解释精度的一条重要途径,对重新评价老井测井资料,寻找漏失掉的油气层具有非常重大的意义。文章提出一种新的信号处理方法—压缩感知方法,它能提升声波测井曲线的纵向分辨率,求出地层的实际时差,并对模型数据和实际声波测井资料进行了处理。结果表明,该方法有效地提升了声波测井曲线的纵向分辨率。%High resolution processing of well logging curve is a important way of improving well logging interpretation accuracy of thin beds which is very meaningful to evaluate old wells logging datas again and search lost oil-gas bearing zone. A new data processing method-Com-pressed Sensing method is proposed to improve vertical resolution of acoustic well logging curve and get the true acoustic slowness of forma-tion. Data from formation model and actual acoustic well logging data are processed by this method. The result shows that vertical resolution of acoustic well logging curve can be improved by this method effectively.

  9. Artificial neural network modeling and cluster analysis for organic facies and burial history estimation using well log data: A case study of the South Pars Gas Field, Persian Gulf, Iran

    Science.gov (United States)

    Alizadeh, Bahram; Najjari, Saeid; Kadkhodaie-Ilkhchi, Ali

    2012-08-01

    Intelligent and statistical techniques were used to extract the hidden organic facies from well log responses in the Giant South Pars Gas Field, Persian Gulf, Iran. Kazhdomi Formation of Mid-Cretaceous and Kangan-Dalan Formations of Permo-Triassic Data were used for this purpose. Initially GR, SGR, CGR, THOR, POTA, NPHI and DT logs were applied to model the relationship between wireline logs and Total Organic Carbon (TOC) content using Artificial Neural Networks (ANN). The correlation coefficient (R2) between the measured and ANN predicted TOC equals to 89%. The performance of the model is measured by the Mean Squared Error function, which does not exceed 0.0073. Using Cluster Analysis technique and creating a binary hierarchical cluster tree the constructed TOC column of each formation was clustered into 5 organic facies according to their geochemical similarity. Later a second model with the accuracy of 84% was created by ANN to determine the specified clusters (facies) directly from well logs for quick cluster recognition in other wells of the studied field. Each created facies was correlated to its appropriate burial history curve. Hence each and every facies of a formation could be scrutinized separately and directly from its well logs, demonstrating the time and depth of oil or gas generation. Therefore potential production zone of Kazhdomi probable source rock and Kangan- Dalan reservoir formation could be identified while well logging operations (especially in LWD cases) were in progress. This could reduce uncertainty and save plenty of time and cost for oil industries and aid in the successful implementation of exploration and exploitation plans.

  10. The Appliacation of The Ultra-Deep Sidetrack Horizontal Well Logging Technology in Tahe Oilfield%超深侧钻水平井测井工艺在塔河油田的应用

    Institute of Scientific and Technical Information of China (English)

    罗荣; 李双林; 罗军

    2012-01-01

    系统分析塔河油田超深侧钻水平井测井作业过程的施工难点,主要包括湿接头对接成功率低、仪器温度性能难以得到有效保证、仪器组合方式受到限制、施工过程中会存在一些井下风险等因素.从井筒准备、仪器串性能检测与组合、施工过程控制、井口电缆防护等4个方面入手,形成较完善的超深侧钻水平井测井工艺和配套施工方案.超深侧钻水平井测井如果井底温度超出了常规仪器175℃/140 MPa的工作范围,应使用高温仪器进行施工;施工前应认真检测仪器的温度性能;采取高温烘箱检测法时其加温温度应提高至175℃;井口电缆防碰装置对钻具输送时测井电缆在井口的安全起到了非常有效的保护;现场多个施工单位之间的紧密配合也是安全顺利取全取准测并资料的关键因素之一.该工艺能够应用到水平井和复杂深井直井施工中.超深侧钻水平井测井工艺在塔河油田先后完成近40井次的施工任务,一次施工成功率达到90%.%There are some difficulties in logging operations in the ultra-deep sidetracked horizontal wells in Tahe oilfield, such as poor wet-connector docking, strict tool temperature-resistant performance,limited logging tool combination and unknown downhole risks while conveying the drilling strings. To solve the above problems, proposed is a new and more complete ultra-deep sidetracked horizontal well logging technique and its supporting logging program, which includes wellbore preparation, tool performance test and combination, logging process control and protection of the wellhead cable. If the downhole temperature is above 175 ℃/140 MPa, we should use higher temperature-resistant logging tool; the tool's temperature performance must be carfully tested before logging operations; if the high temperature drying over testing method is used, the tool's temperature should be warmed up to 175 ℃. The anti

  11. Geophysical well logs and their application to the determination of coal deposition paleoenvironment. Los registros geofisicos de pozo y su aplicacion en la determinacion de paleoambientes de depositacion del carbon

    Energy Technology Data Exchange (ETDEWEB)

    Bolanos, K. (Refinadora Costarricense de Petroleo (Costa Rica))

    Coal evaluation in Costa Rica has been supported by the execution and interpretation of geophysical well logs. These logs permit the measurement of thickness and depth of the coal seams and identification of the lithologic units. The correlation between boreholes would be impossible without conventional well logs (Natural Gamma, Resistivity, and Gamma-Gamma (Density)). Their functions are different but complementary. The density and resistivity logs identify the coal bed, but at the same time they establish the similarities between lithologic columns of different holes, which is not possible from the core descriptions. The natural gamma logs are a very helpful tool in the interpretation of the lithology, depositional environment, morphology of the basin and the stability of the sea level while the deposition was taking place. An example of these interpretations is the correlations between boreholes of the western and northern areas of the Carbon Volio River Basin, where the different units were identified showing variable grain sizes arranged as positive and negative gradations, establishing different levels of transgressive and regressive sequences, where the coal beds are involved. 4 refs., 6 figs.

  12. Study on comprehensive processing on multi-parameters well logging in water control project%水利工程中多参数测井综合处理技术研究

    Institute of Scientific and Technical Information of China (English)

    涂善波; 谢向文; 马若龙; 杨红云

    2013-01-01

    针对水利工程中多参数测井地质解释中的多解性和不确定性,提出将多条测井曲线进行归一化处理,统一多参数测井数据的量纲与幅值,再对归一化后的测井曲线进行加权处理,充分利用多条测井曲线所具有的丰富信息,最后得出一个包含多种测井参数信息的综合处理分析曲线,从而有效地利用多参数测井的优势,减少或削弱部分测井曲线中的偶然误差,提高综合测井地质解释的准确度.通过在岩体风化程度划分与泥化夹层识别中的应用效果分析,证明该方法是较为行之有效的.%In accordance with the multi-interpretations and uncertainty in the geological interpretation of the multi-parameters well logging,it is put forward to normalize several logging traces for integrating both the dimension and the amplitude value of the multi-parameters logging data,and then weighting the normalized logging traces for fully utilization of the rich information from all the logging traces and finally educing an analysis curve consisting of the information of the multi-logging parameters for the comprehensive processing,so as to effectively utilize the advantages of the multi-parameters well logging for decreasing or reducing part of the accidental errors of the logging traces and increasing the accuracy of the comprehensive geological interpretation of the well logging.Through analysis on the effect of the application to dividing of the weathering degrees of rock mass and distinguishing the mud inter-bed,this method is demonstrated to be more feasible and effective.

  13. Scientific results from the deepened Lopra-1 borehole, Faroe Islands: Wire-line log-based stratigraphy of flood basalts from the Lopra-1/1A well, Faroe Islands

    Directory of Open Access Journals (Sweden)

    Boldreel, Lars O.

    2006-07-01

    Full Text Available The present study shows that it is possible to use conventional borehole logs to perform a detailed lithological/stratigraphical division of a column of subaerially extruded basalt. A stratigraphical division of the subaerial flood basalts penetrated by the Lopra-1/1A well has been carried out using new wire-line logging data measured in 1996 in the interval 200–2489 m depth. Resistivity data acquired in the interval 200–2178 m depth during 1981 after the initial drilling of the Lopra-1 well have also been incorporated. Eighty-six individual flow units, 18 compound flows and two dolerite dykes have been identified by combining the NPHI porosity, RHOB density, P-, S- and Stonely-sonic transit time, calliper and resistivity logs. Fifty-two sedimentary/tuffaceous layers have also been identified using the CGR and SGR gamma ray and potassium logs in combination with the aforementioned logs. Within the flow units, sonic velocity, density and resistivity are highest in the core where porosity is lowest. This relation is reversed in the uppermost and basal zones of the flow units. The sonic velocity in the core seems to be independent of the thickness of the flow unit. Porous zones seem abundant in some cores and the total section of cores containing porous zones constitutes more than 70% of the thickness of its flow unit, but where porous zones are absent the core makes up only roughly 50% of the thickness of the flow. It is suggested that the flow units with porous cores represent aa flows (88% of the flow units and the others pahoehoe flows (12% of the flow units.The log pattern of the flow units (crust, core and basal zone is similar to log patterns reported from other basalt plateaux. However the patterns in Lopra-1/1A show a larger variation than elsewhere,suggesting that the flow units are more complex vertically than previously thought. Statistical analysis of P-, S- and Stonely-waves, RHOB, NPHI, resistivity, gamma and calliper logs has

  14. Application of the Bow Tie method for evaluation of safety in the procedure of logging wells; Aplicacion del metodo de Bow Tie para la evaluacion de seguridad en la practica de perfilaje de pozos

    Energy Technology Data Exchange (ETDEWEB)

    Alfonso Pallares, C; Perez Reyes, Y.; Sarabia Molina, I.I. [Centro Nacional de Seguridad Nuclear (CNSN), La Habana (Cuba)

    2013-07-01

    This work consists of an assessment of security in the practice of logging of oil wells, using the method of Bow Tie for being a simple method of evaluation of the risk, which makes it possible in a structured way to set priorities to manage risk.

  15. 页岩气储层测井评价及进展%Well-logging Evaluation in Shale Gas Reservoir and Its Advances

    Institute of Scientific and Technical Information of China (English)

    万金彬; 李庆华; 白松涛

    2012-01-01

    Shale gas reservoir log evaluation differs from that of conventional gas reservoir because over 90% of shale gas reservoirs need fracturing and the shale bed rock has ultra low porosity and permeability. On the basis of researches on a great number of articles about shale gas reservoir log evaluations since 2008, summarized are geologic characteristics of shale gas reservoir, and introduced are the advances of the reservoir core sample analysis technology and suitable logging methods in shale gas reservoirs. Provided are not only the calculation methods of log total organic carbon (TOO, maturity index (MI) and the parameters of rock mechanical properties, but also the fracture evaluation method. Discussed are existing problems in shale gas reservoir log evaluation, and provided is the feasible developing direction in future research. It is believed that it is necessary to build a full information sample database for shale gas reservoir.%页岩基岩孔隙度和渗透率极低,90%以上的页岩气储层需要经过压裂改造才能生产.根据2008年以来与页岩气储层测井评价有关的大量文献,综述了页岩气储层的地质特点,简介了页岩气储层岩心分析技术进展和适用的测井方法.概括给出了适用条件下的测井总有机碳、成熟度指数、岩石力学参数计算方法和裂缝评价方法.探讨了页岩气储层测井评价存在的问题及未来研究可行的发展方向,认为有必要建立信息全面的产气页岩典型样本数据库.

  16. Design of battery control system using for drill pipe conveying storage well-logging tools%钻杆输送存储式测井仪电池控制系统设计

    Institute of Scientific and Technical Information of China (English)

    李明华

    2012-01-01

    The drill pipe conveying no cable storage logging is an important technical.it means to solve the highly deviated and horizontal wells, owe a balance wells difficulty logging. The rational use of the downhole tool battery, battery status monitoring is key to ensure that logging tools work reliably. In this paper, the design of the key part of drill pipe conveying storage logging tool battery control system hardware circuit and software, pressure acquisition temp-drift correction method was submitted, and it summarizes some the advantages of the system in the design and practical engineering applications. The application of the system in Shengli Oilfield and external oilfield demonstrated battery control system ensured that the instrument took complete and accurate logging data, solved a major technical problem of the logging project.%钻杆输送无电缆存储式测井是解决大斜度井、水平井、欠平衡井等高难度测井的重要技术手段.井下仪器电池的合理使用、电池状态的监控是保证测井仪器可靠工作的关键.文中给出了钻杆输送存储式测井仪电池控制系统的硬件电路及软件关键部分设计、压力采集温漂校正方法,总结了该系统在设计及实际工程应用中体现的一些优点.该系统在胜利油田及外部油区的应用表明,电池控制系统能够确保仪器取全取准测井资料,解决了测井工程的一大技术难题.

  17. The Application of High Frequency Ultrasonic Logging Data in Locating Leakage of LG-X Gas Well%高频超声波测漏技术在LG-×气井的应用

    Institute of Scientific and Technical Information of China (English)

    郑友志; 佘朝毅; 马发明; 唐庚; 罗咏枫; 郭建华

    2011-01-01

    The principle of high frequency ultrasonic logging in leakage location is analyzed. Application of high frequency ultrasonic logging in LG-X gas well shows when gas leakage is small this logging can accurately locate the leakage after taking some necessary engineering measures;by testing annulus fluid energy activity in the gas well and with gas well's multi-aspect information it can accurately analyze the reasons of gas leakage; it can locate gas leakage of casing while logging inside the tubing. The log interpretation can provide the basis for establishing corresponding control measures of gas well and gather corresponding technology experience in engineering design, drilling, cementing and completion. It has a wide range of application and promotion prospects.%介绍了高频超声波测漏技术的原理.高频超声波测漏技术在川渝环空带压复杂天然气井LG-×井的成功应用表明,在井筒渗漏量微弱时,通过采用必要的工程措施,能准确找到气体泄漏点位置;通过测试气井环空流体能量活动,综合气井多方面信息,能准确判断气体泄漏的方式及其原因;通过油管测试套管泄漏,其测漏结果可为环空带压气井治理方案及制定相应的控制措施提供依据,为川渝气田气井钻井、固井、完井工程设计和施工中预防常见泄漏点积累相关技术经验,具有推广应用前景.

  18. Recognition method for volcanic rock facies by well logging%利用测井方法识别火山岩岩相方法

    Institute of Scientific and Technical Information of China (English)

    张程恩; 潘保芝; 王飞; 边会媛; 韩雪; 陈刚

    2011-01-01

    利用实际岩石薄片数据及测井数据,通过GR-TH及GR-AC交会图方法将松南气田营城组岩石 结构划分为熔岩结构、熔结结构和凝灰结构3种.凝灰结构和熔结结构对应爆发相,熔岩结构对应喷溢相.结合次生孔隙度的大小及岩心、录井信息对出现的6种亚相:热碎屑流亚相、热基浪亚相、空落亚相、上部亚相、中部亚相和下部亚相进一步划分,其结果与地质上的岩相亚相基本一致.%Using actual rock slices and logging data, the rock structures of Yingcheng Formation in Songnan gas field was divided into lava, welding and tuff structures by the cross plots of GR-TH and GR-AC. Tuff and welding structures correspond to explosive facies, while lava structure corresponds to extrusive facies. The six different subfacies (thermal debris flow, thermal base surge, airfall, upper, middle and lower subfacies) recognized by secondary porosity, core and logging data show a high accuracy compared with the actual geological results.

  19. Geological & Geophysical findings from seismic, well log and core data for marine gas hydrate deposits at the 1st offshore methane hydrate production test site in the eastern Nankai Trough, offshore Japan: An overview

    Science.gov (United States)

    Fujii, T.; Noguchi, S.; Takayama, T.; Suzuki, K.; Yamamoto, K.

    2012-12-01

    In order to evaluate productivity of gas from marine gas hydrate by the depressurization method, Japan Oil, Gas and Metals National Corporation is planning to conduct a full-scale production test in early 2013 at the AT1 site in the north slope of Daini-Atsumi Knoll in the eastern Nankai Trough, Japan. The test location was determined using the combination of detailed 3D seismic reflection pattern analysis, high-density velocity analysis, and P-impedance inversion analysis, which were calibrated using well log data obtained in 2004. At the AT1 site, one production well (AT1-P) and two monitoring wells (AT1-MC and MT1) were drilled from February to March 2012, followed by 1 coring well (AT1-C) from June to July 2012. An extensive logging program with logging while drilling (LWD) and wireline-logging tools, such as GeoVISION (resistivity image), EcoScope (neutron/density porosity, mineral spectroscopy etc.), SonicScanner (Advanced Sonic tool), CMR/ProVISION (Nuclear Magnetic Resonance Tools), XPT (formation pressure, fluid mobility), and IsolationScanner (ultrasonic cement evaluation tools) was conducted at AT1-MC well to evaluate physical reservoir properties of gas hydrate-bearing sediments, to determine production test interval in 2013, and to evaluate cement bonding. Methane hydrate concentrated zone (MHCZ) confirmed by the well logging at AT1-MC was thin turbidites (tens of centimeters to few meters) with 60 m of gross thickness, which is composed of lobe type sequences in the upper part of it and channel sand sequences in the lower part. The gross thickness of MHCZ in the well is thicker than previous wells in 2004 (A1, 45 m) located around 150 m northeast, indicating that the prediction given by seismic inversion analysis was reasonable. Well-to-well correlation between AT1-MC and MT1 wells within 40 m distance exhibited that lateral continuity of these sand layers (upper part of reservoir) are fairly good, which representing ideal reservoir for the production

  20. Using open hole and cased-hole resistivity logs to monitor gas hydrate dissociation during a thermal test in the mallik 5L-38 research well, Mackenzie Delta, Canada

    Science.gov (United States)

    Anderson, B.I.; Collett, T.S.; Lewis, R.E.; Dubourg, I.

    2008-01-01

    Gas hydrates, which are naturally occurring ice-like combinations of gas and water, have the potential to provide vast amounts of natural gas from the world's oceans and polar regions. However, producing gas economically from hydrates entails major technical challenges. Proposed recovery methods such as dissociating or melting gas hydrates by heating or depressurization are currently being tested. One such test was conducted in northern Canada by the partners in the Mallik 2002 Gas Hydrate Production Research Well Program. This paper describes how resistivity logs were used to determine the size of the annular region of gas hydrate dissociation that occurred around the wellbore during the thermal test in the Mallik 5L-38 well. An open-hole logging suite, run prior to the thermal test, included array induction, array laterolog, nuclear magnetic resonance and 1.1-GHz electromagnetic propagation logs. The reservoir saturation tool was run both before and after the thermal test to monitor formation changes. A cased-hole formation resistivity log was run after the test.Baseline resistivity values in each formation layer (Rt) were established from the deep laterolog data. The resistivity in the region of gas hydrate dissociation near the wellbore (Rxo) was determined from electromagnetic propagation and reservoir saturation tool measurements. The radius of hydrate dissociation as a function of depth was then determined by means of iterative forward modeling of cased-hole formation resistivity tool response. The solution was obtained by varying the modeled dissociation radius until the modeled log overlaid the field log. Pretest gas hydrate production computer simulations had predicted that dissociation would take place at a uniform radius over the 13-ft test interval. However, the post-test resistivity modeling showed that this was not the case. The resistivity-derived dissociation radius was greatest near the outlet of the pipe that circulated hot water in the wellbore

  1. Apport d'une approche géostatique dans l'interprétation des mesures de diagraphies différées Enhancing Well Log Interpretation by Using a Geostatistical Approach

    Directory of Open Access Journals (Sweden)

    Denis A.

    2006-12-01

    Full Text Available Nous proposons d'étudier et d'interpréter les données diagraphiques issues de macro-dispositifs en tenant compte, pour chaque mesure, du volume investi. Les macrodispositifs, en raison de leur géométrie, ont un effet intégrateur important sur la mesure diagraphique. Ceci se traduit pour ces dispositifs par une définition ou résolution verticale médiocre. De plus, dans la plupart des cas, le pas d'échantillonnage de la mesure le long du forage est inférieur à la résolution verticale de l'outil : les volumes investis se chevauchent, d'où des données qui ne sont plus additives. Une approche géostatistique des données diagraphiques nous permet d'étudier l'influence de l'effet intégrateur de l'outil sur la valeur de la mesure et de proposer trois méthodes de régularisation des données. Leur objectif est de rendre les données additives par une transformation des supports de mesure (volumes investis. Nous montrerons ainsi par une étude sur des signaux réels et synthétiques puis par l'intermédiaire d'une interprétation combinée de plusieurs diagraphies, qu'une simple régularisation des supports de mesure permet d'une part d'obtenir une information plus rigoureuse avec la mesure diagraphique, et d'autre part d'accroître les possibilités des macrodispositifs et tout particulièrement leur résolution verticale. We propose to study macro logging techniques data by taking into account for each measure the volume affected by the physical process. The volume of sediment affected by a measure carried out with a logging tool (sonic logs, density logs, etc. depends on the nature of the surrounding formations and on the setting of the instrument. The various parameters which influence the measurement are: the source-detector spacing, the spacing between detectors, the sampling interval along a well, and the volume of material considered (the measured entity. Depending on the tool, the measured entity can be either cylindrical

  2. Application of well logging curve reconstruction technique in reservoir prediction%测井曲线重构技术在储层反演中的应用

    Institute of Scientific and Technical Information of China (English)

    余瀚熠; 李瑞; 蒋涔; 赵诚亮

    2009-01-01

    In case of the difference of acoustic impedance between reservoir layers and non-reservoir layers is too little to be differentiated,it is very difficult to identify the reservoir using the inversion method of conventional impedance in some fields though impedance inversion is a important method in reservoir prediction.In order to resolve this problem and decrease the ambiguity,the technique of reservoir-identifying logging curve reconstruction is used.The authors use the technique of GR logging curve reconstruction to predict reservoirs in the depression of Xujia River series in western SiChuan. the resolution of inversion profile has been effectively increased, and the accuracy of the interpretation of lithology has been enhanced. Compared with the conventional impedance inversion, this method achieved remarkable results.%波阻抗反演是储层预测的一种重要手段,但是当储层与非储层(围岩)波阻抗差异不明显时,利用常规波阻抗反演技术难以较好地识别储层.而测井曲线重构技术可以有效提高岩性识别和储层预测的精度,减少多解性.这里结合川西坳陷须家河组勘探实践,利用GR曲线重构声波反演技术对有利区域进行了预测,有效地提高了反演剖面的分辨率,并在一定程度上提高了岩性解释的准确性和精度.同时,比较了常规波阻抗反演与该方法的区别,取得了良好的效果.

  3. An Adaptive Predictive Coding Based on Image Segmentation for Lossless Compression of Ultrasonic Well Logging Images%基于分块自适应预测的超声测井图象无损压缩编码

    Institute of Scientific and Technical Information of China (English)

    骆长江; 俞能海; 周亮

    2001-01-01

    In recent years, image acquisition equipment has been widely adopted in the field of well logging. However, the data transfer rate of the logging system is limited by the transmission cables. Thus, data compression is necessary, but the common compression schemes were found to be not ideal for the well logging images, which have unique properties. In this paper, the properties of typical ultrasonic well logging images were studied and a suitable compression algorithm was proposed. Row and column correlation was found to be the major characteristic of the well logging images and 2-D correlation was not significant. Some subimages showed mainly row correlation and others showed mainly column correlation. According to this observation, an adaptive predictive lossless image compression coding based on image segmentation was proposed. An image is decomposed into blocks and pre-row or pre-column prediction is adaptively selected for every block to perform DPCM coding. An improved LZW algorithm is used to be encode the prediction error. Experiments showed that this coding scheme was able to achieve higher compression ratios than lossless JPEG and JPEG\\|LS for the ultrasonic well logging image, while the complexity was comparable. The algorithm is self\\|adaptive and thus no code table is needed. Since every block is independently processed, the error propagation problem associated with normal DPCM coding schemes is avoided.%针对超声测井图象数据量较大,且要求实时传输的问题,提出了一种基于分块自适应预测的无损压缩编码方法.该方法首先对原图象分块;然后在每一子块内自适应选择预测方案,并进行DPCM编码;最后采用改进的LZW算法对差值图象进行编码输出.经过实验表明,该算法比较符合超声测井图象特点,其压缩倍数较现有无损压缩算法有很大提高,而算法复杂度没有明显增加,同时所需内存开销较小,因而特别适用于实时遥测系统.

  4. Causes Analysis of Logging Obstructing and Sticking in the Ultra-deep Well and Solution Methods%超深井测井遇阻遇卡原因分析及解决对策

    Institute of Scientific and Technical Information of China (English)

    罗荣

    2012-01-01

    Because Ordovician reservoir is deeper, the drilled wells are ultra deep wells in Tahe oilfield. From engineering point, introduced are logging obstructing causes in ultra-deep wells, such as, irregular borehole, sand bridge, higher viscosity drilling fluid, poor quality of mud cake, heavy oil in wellbore, poor well trajectory, etc. Analyzed are three causes of logging sticking which are pressure difference, sloughing and key seating. By improving borehole cleanup and logging technology, the risk of logging obstructing and sticking is obviously controlled. Proposed are two solutions: The key to reduce the risk is to control drilling quality, and ensure the down hole tools and wireline safety when changing tool string connection mode.%塔河油田奥陶系油藏由于埋深较深,所钻井都为超深井.从工程角度介绍了井眼不规则、砂桥、钻井液黏度过高、泥饼质量差、井内出稠油、井眼轨迹不好等造成超深井测井遇阻等原因 ;对电缆仪器吸附卡、掉块卡、键槽卡3种超深井测井遇卡原因进行了分析.通过有针对性地进行测井前井筒准备、改进和完善测井工艺等2个方面工作,使工区测井遇阻卡情况得到明显控制.减少测井遇阻遇卡的核心是抓好钻井过程的控制 ;改变仪器串连接方式必须保证井下仪器和电缆的安全.

  5. 桥式湿接头水平井测井工艺技术研究及应用%Research and Application of Bridge Wet-connector Horizontal Well Logging Technology

    Institute of Scientific and Technical Information of China (English)

    张炳军; 陈建波; 成军军; 李金刚; 任小虎; 杨新宏

    2016-01-01

    The horizontal well logging technology with pipe conveyed wet‐connector tools which is based on the specific circumstance of the horizontal section whose length is longer than the surface casing needs to repeat the procedures such as opening mud pumps ,conveying docking tools with the pressurized mud ,the wet‐connector tools docking and recording logging curves . Impacted by those poor conditions of wells ,drilling rigs and mud ,the success rate of well logging keeps lower , the well drilling controlling is even riskier . To overcome above‐mentioned difficulties and standardize the process ,this paper introduces a new technology w hich is named the horizontal well logging technology with bridge wet‐connector tools realizes docking repeatly in the vertical well section by those gravities of the bridge wet‐connector tools , flexible cable connectors and other innovative tools .Its attractive advantage is achieving docking with gravity ’s help rather than the force of the pressurized mud .Practice proves that it has reached the goal of improving the working efficiency ,increasing the success ratio of well logging ,reducing the actual usage demand ,decreasing the risk of operations and ensuring the stability of the borehole wall .%在水平段长度大于表层套管长度的水平井进行钻具输送湿接头测井时,须在水平井段进行多次泵送对接,受井况、钻机及泥浆性能等影响,测井作业一次成功率低,井控风险大。介绍了一种新的只在直井段应用工具重力实现多次对接的桥式湿接头水平井测井工艺技术,通过应用桥式湿接头、柔性电缆连接器等创新工具,规范施工流程,实现了水平井无需泵送对接测井。经过实际应用,达到了提高测井时效和成功率、降低钻机性能和环境要求、减小施工风险和保障井筒安全的目的。

  6. The Design and Implement of Well-log Data Parsers and Imaging Controller%测井数据解析与成像控件的设计与实现

    Institute of Scientific and Technical Information of China (English)

    董音; 王国基; 张发光; 蒋海军

    2015-01-01

    There are many problems with well-logging data storages within domestic in China. The data formats are different from one product producer to another. How to process different data from various producers, and how to propose this bug to break the boundary between different producers is one of the problems. This paper is aimed at deal this problem with deep research into many well-logging data format, and then we designed an Imaging Controller to common use. We focused in data model design, well logging imaging, drawing template, and component extension.%目前国内测井文件格式多样,测井分析软件五花八门,处理不同厂家的测井数据需要不同的测井软件,如何才能打破厂家之间的界限,用一款软件处理所有的测井数据呢?该文对测井数据格式的解析与成像控件的设计进行了深入研究。主要从数据模型的设计、测井图像绘制、绘图模板、组件的扩展进行了详细的介绍与分析。

  7. 应用信息粒方法构建测井岩性解释模型%USING INFORMATION GRANULATION TO CONSTRUCT THE WELL-LOGGING LITHOLO-GY INTERPRETATION MODEL

    Institute of Scientific and Technical Information of China (English)

    余翔宇; 徐义贤; 骆淼

    2012-01-01

    基于模糊聚类、神经网络等常用测井岩性识别方法,提出应用信息粒(Information Granulation)技术建立测井数据到岩性知识的映射模型.并以中国大陆科学钻探(CCSD)的测井数据为例,详细介绍了这种岩性解释方法的应用过程及其所取得的良好应用效果.%By analyzing some data processing methods which are common used in well-logging as fuzzy clustering, Artificial neural network etc. the paper consequently presents the method based on information granulation (IG) to construct the mapping model from well-logging data to lithol-ogy knowledge. Take the well - logging data from Chinese continental scientific drilling (CCSD) as an instance, the author described how to establish such interpretation model and an excellent results it had achieved.

  8. Seismic reflection data imaging and interpretation from Braniewo2014 experiment using additional wide-angle refraction and reflection and well-logs data

    Science.gov (United States)

    Trzeciak, Maciej; Majdański, Mariusz; Białas, Sebastian; Gaczyński, Edward; Maksym, Andrzej

    2015-04-01

    Braniewo2014 reflection and refraction experiment was realized in cooperation between Polish Oil and Gas Company (PGNiG) and the Institute of Geophysics (IGF), Polish Academy of Sciences, near the locality of Braniewo in northern Poland. PGNiG realized a 20-km-long reflection profile, using vibroseis and dynamite shooting; the aim of the reflection survey was to characterise Silurian shale gas reservoir. IGF deployed 59 seismic stations along this profile and registered additional full-spread wide-angle refraction and reflection data, with offsets up to 12 km; maximum offsets from the seismic reflection survey was 3 km. To improve the velocity information two velocity logs from near deep boreholes were used. The main goal of the joint reflection-refraction interpretation was to find relations between velocity field from reflection velocity analysis and refraction tomography, and to build a velocity model which would be consistent for both, reflection and refraction, datasets. In this paper we present imaging results and velocity models from Braniewo2014 experiment and the methodology we used.

  9. 基于纹理特征的测井图像分类算法的研究%State-of-the-Art on Texture-Based Well Logging Image Classification

    Institute of Scientific and Technical Information of China (English)

    王华锋; 王玉婷; 柴华

    2013-01-01

    Imaging well logging can easily and effectively determine the existing locations of the reservoirs,because of its ability of showing the stratal lithologies and geometric changes in the form of image.Recently,imaging log is used widely for its higher discernibility and has become a research hotspot in the field of well logging technology.How to fully utilize image processing,pattern recognition and other related theoretical methods for both more precise quantitative evaluation of imaging logging and the interpretation of images is the focus.Texture analysis plays an important role in the field of computer vision and pattern recognition.This paper surveys the research background and current situation of the imaging well logging,and then reviews most existing typical algorithms for texture analysis.It focuses on the grey level co-occurrence matrices (GLCM) algorithm,local binary patterns algorithm (LBP),Gabor transform,wavelet transform,as well as Contourlet transform,and analyzes their respective pros and cons.Based on this,and considering the features of the logging images,this paper gives a method for the classification of the well logging images,and proposes a system model of logging image recognition and classification.The problems,prospects for future development and suggestions for further research works are put forward at the end of the paper.%成像测井由于其能够以图像的形式直观表示地层的岩性与结构特征,已成为测井领域的研究热点之一.如何利用图像处理、模式识别等相关理论方法对成像测井图像进行较为精确的定量评价和解释是研究的核心.首先从成像测井的研究背景及现状出发,详细比较和分析了纹理分析的各种算法.通过对灰度共生矩阵法、LBP算法、Gabor变换、小波变换、Contourlet变换等算法进行比较,给出成像测井图像分类过程中特征提取的参考建议.在此基础上,结合测井图像的模式特点,提出了一个基

  10. 中9-31井多臂井径和井温噪声资料综合解析%Interpretation Analysis Based on Multi-arm Caliper and Temperature & Noise Logging Data in Zhong 9-31 Well

    Institute of Scientific and Technical Information of China (English)

    王海莹; 王莱雪; 王娇莉

    2015-01-01

    Based on the temperature&noise logging data of Zhong 9-31 well, and combined with the MIT logging data of the same well in the same year, this paper disproved the original hypothesis, and drew the correct conclusion. The comprehensive interpretation of logging data can improve the accuracy of the interpretation results.%文章在中9-31井井温噪声测井资料分析基础上,结合同年同一管柱结构下的四十臂井径测井资料,对井温噪声测井资料中的矛盾点进行推论和证实,最后推翻最初假设,得出正确解释结论,实现测井资料综合解释,确保测井解释成果的准确性。

  11. 江苏省仪征市某井综合地球物理测井成果分析%On analysis of comprehensive geophysical logging of some well at Yizheng city of Jiangsu province

    Institute of Scientific and Technical Information of China (English)

    刘峻; 沈华光; 陈海军

    2012-01-01

    The paper undertakes the comprehensive geophysical logging of some well at Yizheng city of Jiangsu province by adopting the resistivity,the spontaneous potential and the natural gamma,undertakes the lithology determination of the well based on the data for the logging,and the results show can interpret the changes of the grain succession and the face by the comprehensive geophysical logging and the sedimentary cycle can be directly judged by combining the rock core.%用电阻率、自然电位、自然伽马对江苏省仪征市某井进行了综合地球物理测井,以测井数据为基础,对该井进行了岩性划分,结果显示通过综合地球物理测井,可以较好地解释粒序变化和相序变化,结合岩芯可以更直观地判断沉积旋回。

  12. Application of neural network technology in interpretation of well logging parameters%神经网络技术在录井参数解释中的应用

    Institute of Scientific and Technical Information of China (English)

    单元伟

    2014-01-01

    近年来,随着计算机技术的飞速发展,涌现出许多新方法新技术,人工神经网络技术就是其中之一。神经网络模型的语言识别、图像处理等方面获得了有价值的应用和进展,其研究成果也很快被引入到油气田勘探开发领域,其中包括资料的处理及解释。将计算机神经网络技术应用于录井行业,处理受钻井条件影响大、地质条件复杂,油气水层识别有一定困难的录井资料解释中,已成为目前国内录井行业探索的一个方向。%Artificial neural network technology is one of the new methods and technologies springing up along with the rapid development of computer technology in recent years. Valuable application and progress of neural network model have been achieved in the fields of speech reorganization and image processing. Its research findings have been introduced to the oil and gas field exploration and development,including the processing and interpretation of documents. It has become a new direction of domestic investigation in well logging to apply the artificial neural network technology to the logging of well. It is capable of processing and explaining well logging documents collected from the wells which are greatly influenced by the condition of well drilling,located in complicated geological conditions,and are difficult in oil-gas-water layers identification.

  13. Middle Jurassic Yanan Formation Sequence Stratigraphic Well Logging Response Characteristics in Ningdong Coalfield%宁东煤田中侏罗纪延安组层序地层测井响应特征

    Institute of Scientific and Technical Information of China (English)

    冯希文

    2012-01-01

    以钻井、测井资料为基础,以高分辨率层序地层学为指导,通过层序界面和层序地层的测井响应特征研究,对宁东煤田中侏罗纪延安组含煤岩系进行了精细划分与对比.结果表明,宁东煤田中侏罗纪延安组层序地层界面位于测井曲线基值发生明显改变的转折点上,大型河道冲刷面、湖泛面以及进积(加积)与退积的相互转换面也是层序界面的发育位置;层序地层的测井响应特征中,进积类型测井曲线呈现漏斗型,退积类型测井曲线呈现钟形,加积类型测井曲线呈现箱型;宁夏宁东煤田中侏罗纪延安组可以识别出3个三级层序,共识别出9个层序组,并可进一步详细划分为9个四级层序.%Based on drilling and well logging data, guiding by the high resolution sequence stratigraphy, studied sequence boundary and sequence stratigraphic well logging response characteristics, carried out refined division and correlation of middle Jurassic Yanan Formation coal-bearing strata in the Ningdong coalfield. The result has demonstrated that the Yanan Formation sequence stratigraphic boundaries used to be on the abrupt turning points of logging trace basic values; switching planes between surfaces of large sized channel scouring, lacustrine flooding, prograding (aggrading) and retrograding also the developing places of stratigraphic boundaries. In sequence stratigraphic well logging response characteristics, prograding typed logging traces present infundibuliform, while retrograding campaniform and aggrading box-form. 3 third-order sequences, 9 sequence sets can be identified in middle Jurassic Yanan Formation in Ningdong coalfield in Ningxia, and then can be further subdivided into 9 fourth-order sequences.

  14. 页岩气储层测井解释模型建立与评价方法研究%The Model Establishment and Evaluation Methods of Shale Gas Reservoir Well Logging Interpretation

    Institute of Scientific and Technical Information of China (English)

    金力钻; 孙玉红; 杨铁梅

    2015-01-01

    According to the characteristics of Cretaceous shale Toolebuc reservoir in the north eastern margin of EROMANGA basin,the core of well logging was determined,and the shale contents of main minerals and total porosity were established using logging data and experimental results regression method.A set of logging interpretation models of hydrocarbon saturation,permeability and the total content of gas were established,comprehensive interpretation and evaluation method for the area of shale gas reservoir layer were also built.The method can provide refined interpretation for shale reservoirs of Toobeluc and has a good application effect.%针对 EROMANGA 盆地北东缘白垩系 Toolebuc 页岩储层特征,从测井岩心刻度出发,利用测井数据与实验结果回归方法,建立页岩的主要矿物含量以及总孔隙度、含烃饱和度、渗透率、总含气量等测井解释模型,建立一套适合于该地区的页岩气储层综合解释评价方法,用此方法对 Toobeluc 页岩储层进行精细解释,具有较好的应用效果。

  15. 建111井致密砂岩气显示录测井解释研究%On Study of Logging Interpretation of Tight Sandstone Gas Show in Jian Well 111

    Institute of Scientific and Technical Information of China (English)

    张琼; 张伟; 夏敬民; 李光华

    2012-01-01

    致密砂岩气属于非常规天然气资源家族的一员,其储层孔隙度低、渗透率低、随钻录井气测显示弱、气水关系复杂。这些特征,给录测井解释评价带来诸多需要攻关与认识的技术难题。在建南地区首口致密砂岩气勘探开发试验井—建111井,江汉录测井人员于须家河组须六段致密砂岩储层发现并解释典型致密砂岩气层1层厚9.0m,完井测试,日产天然气3 000m3。须六段致密砂岩气的成功解释评价,丰富和验证了现有的录测井致密砂岩气解释评价方法,为下步该地区致密砂岩气开发录测井解释评价积累一定的实践经验。%Tight sandstone gas belongs to an unconventional gas resource.Its reservoir has a low void ratio and permeability.The show effect for gas survey in well drilling and logging is weak and gas-water relation is complicated.All this has brought problems technologically to logging interpretation and evaluation which need to be understood and solved.In the process of exploring and developing the first test well(Jian Well 111) with tight sandstone gas in Jiannan area,Jianghan well logging staff have discovered and interpreted typical tight sandstone gas reservoir of 9.0 m thickness per layer in tight sandstone reservoir of Member Xu 6 in Xujiahe Formation.Output of natural gas a day reaches 3000m3 during well completing test.Success in interpreting and evaluating tight sandstone gas of Member Xu 6 has enriched and checked existing evaluation method,and accumulated some practical experience for well logging interpretation and evaluation in the next development of tight sandstone gas in Jiannan area.

  16. Results of investigation at the Miravalles Geothermal Field, Costa Rica: Part 1, Well logging. Resultados de las investigaciones en el campo geotermico de Miravalles, Costa Rica: Parte 1, Registros de pozos

    Energy Technology Data Exchange (ETDEWEB)

    Dennis, B.R.; Lawton, R.G.; Kolar, J.D.; Alvarado, A.

    1989-03-01

    The well-logging operations performed in the Miravalles Geothermal Field in Costa Rica were conducted during two separate field trips. The Phase I program provided the deployment of a suite of high-temperature borehole instruments, including the temperature/rabbit, fluid sampler, and three-arm caliper in Well PGM-3. These same tools were deployed in Well PGM-10 along with an additional survey run with a combination fluid velocity/temperature/pressure instrument used to measure thermodynamic properties under flowing well conditions. The Phase II program complemented Phase I with the suite of tools deployed in Wells PGM-5, PGM-11, and PGM-12. 4 refs., 25 figs., 1 tab.

  17. Well logging evaluation of water-flooded layers and distribution rule of remaining oil in marine sandstone reservoirs of the M oilfield in the Pearl River Mouth basin

    Science.gov (United States)

    Li, Xiongyan; Qin, Ruibao; Gao, Yunfeng; Fan, Hongjun

    2017-03-01

    In the marine sandstone reservoirs of the M oilfield the water cut is up to 98%, while the recovery factor is only 35%. Additionally, the distribution of the remaining oil is very scattered. In order to effectively assess the potential of the remaining oil, the logging evaluation of the water-flooded layers and the distribution rule of the remaining oil are studied. Based on the log response characteristics, the water-flooded layers can be qualitatively identified. On the basis of the mercury injection experimental data of the evaluation wells, the calculation model of the initial oil saturation is built. Based on conventional logging data, the evaluation model of oil saturation is established. The difference between the initial oil saturation and the residual oil saturation can be used to quantitatively evaluate the water-flooded layers. The evaluation result of the water-flooded layers is combined with the ratio of the water-flooded wells in the marine sandstone reservoirs. As a result, the degree of water flooding in the marine sandstone reservoirs can be assessed. On the basis of structural characteristics and sedimentary environments, the horizontal and vertical water-flooding rules of the different types of reservoirs are elaborated upon, and the distribution rule of the remaining oil is disclosed. The remaining oil is mainly distributed in the high parts of the structure. The remaining oil exists in the top of the reservoirs with good physical properties while the thickness of the remaining oil ranges from 2–5 m. However, the thickness of the remaining oil of the reservoirs with poor physical properties ranges from 5–8 m. The high production of some of the drilled horizontal wells shows that the above distribution rule of the remaining oil is accurate. In the marine sandstone reservoirs of the M oilfield, the research on the well logging evaluation of the water-flooded layers and the distribution rule of the remaining oil has great practical significance

  18. 常规地球物理测井资料在盐井工程地质解释中的综合应用%Comprehensive Application of Geophysical Logging Data in Geological Interpretation of Salt Well Engineering

    Institute of Scientific and Technical Information of China (English)

    朱勇毅

    2014-01-01

    The application of geophysical well logging data is very extensive and the most important application is in the engineering of well exploration and production and geological interpretation that is the interpretation of objective layer (rock salt layer) which includes single well interpretation ,the interpretation of the structure of the whole mining area and the distribution of rock salt and the interpretation of the logging data which will be used in the salt well engineering.%地球物理测井资料的应用非常广泛,在盐矿开采的探井和生产井中的工程和地质解释应用最主要,就是对目的层(岩盐层)的解释,包括单井解释和整个矿区构造及岩盐分布的解释,其次就是围绕盐井工程施工中所用到的测井资料的解释。

  19. GEOPHYSICAL WELL LOG/CORE DESCRIPTIONS, CHEROKEE AND BUG FIELDS, SAN JUAN COUNTY, UTAH, AND LITTLE UTE AND SLEEPING UTE FIELDS, MONTEZUMA COUNTY, COLORADO

    Energy Technology Data Exchange (ETDEWEB)

    Thomas C. Chidsey Jr; David E. Eby; Laura L. Wray

    2003-12-01

    Over 400 million barrels (64 million m{sup 3}) of oil have been produced from the shallow-shelf carbonate reservoirs in the Pennsylvanian (Desmoinesian) Paradox Formation in the Paradox Basin, Utah and Colorado. With the exception of the giant Greater Aneth field, the other 100 plus oil fields in the basin typically contain 2 to 10 million barrels (0.3-1.6 million m{sup 3}) of original oil in place. Most of these fields are characterized by high initial production rates followed by a very short productive life (primary), and hence premature abandonment. Only 15 to 25 percent of the original oil in place is recoverable during primary production from conventional vertical wells. An extensive and successful horizontal drilling program has been conducted in the giant Greater Aneth field. However, to date, only two horizontal wells have been drilled in small Ismay and Desert Creek fields. The results from these wells were disappointing due to poor understanding of the carbonate facies and diagenetic fabrics that create reservoir heterogeneity. These small fields, and similar fields in the basin, are at high risk of premature abandonment. At least 200 million barrels (31.8 million m{sup 3}) of oil will be left behind in these small fields because current development practices leave compartments of the heterogeneous reservoirs undrained. Through proper geological evaluation of the reservoirs, production may be increased by 20 to 50 percent through the drilling of low-cost single or multilateral horizontal legs from existing vertical development wells. In addition, horizontal drilling from existing wells minimizes surface disturbances and costs for field development, particularly in the environmentally sensitive areas of southeastern Utah and southwestern Colorado.

  20. Optimal Selection Technology of Well Logging Items in Complex Lithology Pattern Indentification%复杂岩性模式识别中测井项目优化选择技术

    Institute of Scientific and Technical Information of China (English)

    张美玲; 蔺建华; 曾科; 杨陆

    2012-01-01

    在利用模式聚类判别方法建立复杂岩性集合判别函数时,需要优选出对岩性集合敏感的测井项目,以有效克服所有测井项目均参与而造成的相互掣肘、矛盾现象.依据构建集合内均匀度参数及集合间距离参数,实现复杂岩性集合判别中测井项目优化选择技术.以海拉尔盆地的4大类岩性集合(一般沉积岩、火山碎屑岩、火山碎屑沉积岩、火山熔岩等)为应用实例,优选后判别符合率明显改善,说明了方法的有效性.%When building the discriminant function of complex lithology set by using the method of pattern cluster discrimination, to select the well logging programs are needed which are sensitive to the lithology sets optimally, and then the impede and contradiction can be overcomed because of the participation of all the well logging programs efficiently. The optimal selection technology of well logging programs in the discrimination of the complex lithology sets is gotten, which based on building the parameter of the evenness and the distance between the sets in the aggregation. Based on the 4 broad headings of Hailaer basin (general sedimentary rock, the volcanoclastic rock, the volcanoclastic sedimentary rock, lava and etc. ) , the discrimination coincidence rate is better apparently, and this confirms that the method is effective.

  1. THE APPLICATION OF GENETIC ALGORITHM TO THE PARAMETER ESTIMATION IN WELL LOGGING INTERPRETATION%遗传算法在估计测井解释参数方面的应用

    Institute of Scientific and Technical Information of China (English)

    闫桂京; 潘保芝

    2001-01-01

    The response equations of the models applied in well logging evaluation include some parameters of which selection are critical for the precision of well logging evaluation. The genetic algorithm is a self-adaptive global optimizing method and has the flexibility for solving various special cases. In this paper, a brief introduction of the theory and operation rules of the genetic algorithm was given. Then its potential application to the parameter estimation in the well logging interpretation was discussed using the Archie's formulas for water saturation estimation as an example. The results show that method is easy and effective for the application..%测井响应方程中通常包括一些常量参数,这些参数的选取直接影响解释结果的精度。遗传算法是一种自适应全局优化算法,具有求解各种特殊问题的灵活性。作者在本文简要地介绍了遗传算法的基本原理和运算规则,并以阿尔奇含水饱和度公式中a、m、n等参数的选取为例,探讨了将遗传算法应用于测井解释参数估计中的潜力。实践证明,该方法简便,应用效果较好。

  2. Porosity Log Prediction Using Artificial Neural Network

    Science.gov (United States)

    Dwi Saputro, Oki; Lazuardi Maulana, Zulfikar; Dzar Eljabbar Latief, Fourier

    2016-08-01

    Well logging is important in oil and gas exploration. Many physical parameters of reservoir is derived from well logging measurement. Geophysicists often use well logging to obtain reservoir properties such as porosity, water saturation and permeability. Most of the time, the measurement of the reservoir properties are considered expensive. One of method to substitute the measurement is by conducting a prediction using artificial neural network. In this paper, artificial neural network is performed to predict porosity log data from other log data. Three well from ‘yy’ field are used to conduct the prediction experiment. The log data are sonic, gamma ray, and porosity log. One of three well is used as training data for the artificial neural network which employ the Levenberg-Marquardt Backpropagation algorithm. Through several trials, we devise that the most optimal input training is sonic log data and gamma ray log data with 10 hidden layer. The prediction result in well 1 has correlation of 0.92 and mean squared error of 5.67 x10-4. Trained network apply to other well data. The result show that correlation in well 2 and well 3 is 0.872 and 0.9077 respectively. Mean squared error in well 2 and well 3 is 11 x 10-4 and 9.539 x 10-4. From the result we can conclude that sonic log and gamma ray log could be good combination for predicting porosity with neural network.

  3. 柴北缘含煤区地层测井物性特征分析%Strata Well Logging Characteristic Analysis of Coal-bearing Area on North Margin of Qaidam Basin

    Institute of Scientific and Technical Information of China (English)

    潘语录

    2011-01-01

    Taking the Iqe coalfield on the north margin of the Qaidam Basin, canied out analysis of well logging response characteristics of various lithologic rocks in coal-bearing strata. The analysis has considered that the geophysical characters of the area belong to "simple and easy to distinguish" type, that is to say the physical property of coal seams and rocks has rather distinct differences, different lithologic rocks have obvious different characters on gamma-gamma, gamma-ray and resistivity logging traces. Based on logging (races characteristic variation amplitudes, high or low crest values can distinguish and correlate coal seams and rocks effectively. On the practical logging interpretation result basis, carried out logging trace combination characteristics description of marker bed sectors of upper Jurassic Hongshuigou and Caishib'ng formations, middle-lower Jurassic Dameigou Formation shale, upper and lower coal-bearing members.%以柴达木盆地北缘的鱼卡煤田为例,对含煤地层中的各种岩性的测井响应特征进行分析,认为该区的地球物理特征属“简单易区别”型,即煤岩层的物性差异较大,物性条件较好,不同岩性在伽马-伽马、自然伽马、电阻率等测井曲线上的特征明显,根据曲线的变化幅度、峰值高低等曲线特征,可有效进行煤岩层划分与对比.根据实际测井解释成果,对侏罗系上统红水沟组、采石岭组、侏罗系中-下统大煤沟组的页岩段、上含煤段及下含煤段等标志层段的测井曲线组合特征进行了描述.

  4. Processing, Analysis, and General Evaluation of Well-Driller Logs for Estimating Hydrogeologic Parameters of the Glacial Sediments in a Ground-Water Flow Model of the Lake Michigan Basin

    Science.gov (United States)

    Arihood, Leslie D.

    2009-01-01

    In 2005, the U.S. Geological Survey began a pilot study for the National Assessment of Water Availability and Use Program to assess the availability of water and water use in the Great Lakes Basin. Part of the study involves constructing a ground-water flow model for the Lake Michigan part of the Basin. Most ground-water flow occurs in the glacial sediments above the bedrock formations; therefore, adequate representation by the model of the horizontal and vertical hydraulic conductivity of the glacial sediments is important to the accuracy of model simulations. This work processed and analyzed well records to provide the hydrogeologic parameters of horizontal and vertical hydraulic conductivity and ground-water levels for the model layers used to simulated ground-water flow in the glacial sediments. The methods used to convert (1) lithology descriptions into assumed values of horizontal and vertical hydraulic conductivity for entire model layers, (2) aquifer-test data into point values of horizontal hydraulic conductivity, and (3) static water levels into water-level calibration data are presented. A large data set of about 458,000 well driller well logs for monitoring, observation, and water wells was available from three statewide electronic data bases to characterize hydrogeologic parameters. More than 1.8 million records of lithology from the well logs were used to create a lithologic-based representation of horizontal and vertical hydraulic conductivity of the glacial sediments. Specific-capacity data from about 292,000 well logs were converted into horizontal hydraulic conductivity values to determine specific values of horizontal hydraulic conductivity and its aerial variation. About 396,000 well logs contained data on ground-water levels that were assembled into a water-level calibration data set. A lithology-based distribution of hydraulic conductivity was created by use of a computer program to convert well-log lithology descriptions into aquifer or

  5. 4D reservoir characterization using well log data for feasible CO2-enhanced oil recovery at Ankleshwar, Cambay Basin - A rock physics diagnostic and modeling approach

    Science.gov (United States)

    Ganguli, Shib Sankar; Vedanti, Nimisha; Dimri, V. P.

    2016-12-01

    In recent years, rock physics modeling has become an integral part of reservoir characterization as it provides the fundamental relationship between geophysical measurements and reservoir rock properties. These models are also used to quantify the effect of fluid saturation and stress on reservoir rocks by tracking the changes in elastic properties during production. Additionally, various rock physics models can be applied to obtain the information of rock properties away from existing drilled wells, which can play a crucial role in the feasibility assessment of CO2-enhanced oil recovery (EOR) operation at field. Thus, the objective of this study is to develop a rock-physics model of the Ankleshwar reservoir to predict the reservoir response under CO2-EOR. The Ankleshwar oil field is a mature field situated in Cambay Basin (Western India) that witnessed massive peripheral water flooding for around 40 years. Since the field was under water flooding for a long term, reasonable changes in reservoir elastic properties might have occurred. To identify potential reservoir zone with significant bypassed (or residual) oil saturation, we applied the diagnostic rock physics models to two available wells from the Ankleshwar oil field. The results clearly indicate transitions from clean sands to shaly sands at the base, and from sandy shale to pure shale at the top of the reservoir pay zone, suggesting a different seismic response at the top when compared to the base of the reservoir in both the wells. We also found that clay content and sorting affects the elastic properties of these sands, indicating different depositional scenario for the oil sands encountered in the Ankleshwar formation. Nevertheless, the rock physics template (RPT) analysis of the well data provides valuable information about the residual oil zone, a potential target for CO2-EOR. Further, a 4D reservoir characterization study has been conducted to assess the seismic detectability of CO2-EOR, and we

  6. Digital archive of drilling mud weight pressures and wellbore temperatures from 49 regional cross sections of 967 well logs in Louisiana and Texas, onshore Gulf of Mexico basin

    Science.gov (United States)

    Burke, Lauri A.; Kinney, Scott A.; Kola-Kehinde, Temidayo B.

    2011-01-01

    This document provides the digital archive of in-situ temperature and drilling mud weight pressure data that were compiled from several historical sources. The data coverage includes the states of Texas and Louisiana in the Gulf of Mexico basin. Data are also provided graphically, for both Texas and Louisiana, as plots of temperature as a function of depth and pressure as a function of depth. The minimum, arithmetic average, and maximum values are tabulated for each 1,000-foot depth increment for temperature as well as pressure in the Texas and Louisiana data.

  7. The automatic interpretation of the natural {gamma}-rays in well logging at the phosphatic deposits in the Palmyra region in Syria

    Energy Technology Data Exchange (ETDEWEB)

    Asfahani, J.; Kamarji, Z. [Atomic Energy Commission, Damascus (Syrian Arab Republic)

    1996-05-01

    A new methodology has been introduced for the automatic interpretation of natural {gamma}-rays in wells and pits, using numerical analysis. This approach is aimed at the accurate determination of radioactive lithology levels, the thickness and the radioactive intensities. A model of four main radioactive types (K, H, A and Q) has been suggested in the prospecting region for phosphatic deposits and radioactive materials at the Khneifiss and Al-Sharkieh mines (in the Syrian Palmyrides). A good correlation has been found between the results of this methodology and the lithology of studied boreholes. (Author).

  8. 天然气水合物储集类型的测井响应特征%Well Logging Response Characteristics of Various Natural Gas Hydrate Accumulation Types

    Institute of Scientific and Technical Information of China (English)

    田贵发; 栾安辉; 赵平; 弓佩章

    2013-01-01

    通过木里煤田聚乎更煤矿区四井田、哆嗦公马、雪霍立三个矿区(井田)大量测井资料的分析和研究,并结合祁连山冻土区天然气水合物DK-1科学试验孔测井资料的综合对比和解释,对煤田常规测井参数在天然气水合物储集层上的响应特征进行了分析。根据该区常年冻土(岩)的勘探成果及测井曲线响应特征,将陆源天然气水合物储集层分为生气层与储集层的相对位置、纵向位置、空间位置、储集介质等四大类,上生下储、下生上储、自生自储、冻土(岩)带内、增温带内等11个亚类。在此基础上建立了与富冰型、煤层自储型、孔隙型、裂隙型等多种储集模式对应的典型测井曲线响应特征。利用测井方法识别天然气水合物储集层的方法,可为青藏高原研究、评价、勘查、开发天然气水合物提供可靠的解释依据。%Based on analyses and studies of large amount well logging data from 3 mine areas (minefields) in the Muri coalfield, com-bined with correlation and interpretation of well logging data from natural gas hydrate DK-1 scientific test hole in the Qilian Mts. per-mafrost region, carried out analysis of natural gas hydrate reservoir response characteristics on coalfield conventional well logging pa-rameters. According to exploration results and logging traces response characteristics of perennial frozen soil (rock) in the area, based on four classification bases of relative position of generation layer and reservoir, vertical position, spatial position and medium of accu-mulation, divided the natural gas hydrate accumulation into eleven types of generation layer upper reservoir lower, generation layer low-er reservoir upper, identical generation layer and reservoir, within zone of frozen soil (rock), within zone of constructive temperature and so on. On this basis established typical logging trace response characteristics corresponding to

  9. Flowmeter logging in water wells of great diameter, methodology and applications. Testificacion de flowmeter en pozos de agua de gran diametro. Metodologia y aplicaciones

    Energy Technology Data Exchange (ETDEWEB)

    Diaz Curiel, J.; Martin, D.A.; Rozycki, A.; Maldonado, A. (Escuela Tecnica Superior Ingenieros Minas, Universidad Politecnica de Madrid. Madrid (Spain))

    1994-01-01

    Several deep water supply wells have been carried out by the ''Canal de Isabel II'' in the western area of Madrid, within the emergency project developed in order to overcome the water shortage in the years 1992 and early 1993. The Department of Applied Geophysics and Geochemical Prospecting of the Mining Engineering School in Madrid updates and up graduates the data-acquisition methodology and interpretation of continuous spinner flowmeter data. When developing this methodology, besides the interpretation problems due to great diameter, we meet also a series of technical problems attempts and whose classical absence of divulgation has caused this technique to be scarcely used in Spain. So, in this paper we state a Glossary of Solutions to both aspects. (Author)

  10. The application of well logging and seismic modeling to assess the degree of gas saturation in Miocene strata (Carpathian Foredeep, Poland)

    Science.gov (United States)

    Marzec, Paweł; Niepsuj, Magdalena; Bała, Maria; Pietsch, Kaja

    2014-02-01

    The presence of natural gas in the pore space of reservoir rocks results in a significant decrease in P-wave velocity. Even low gas saturation can generate seismic anomalies (DHI) and false image of gas accumulation of economic importance. This article presents an attempt to evaluate gas saturation from 2D seismic section in the Miocene sandstone strata in the south-eastern part of the Carpathian Foredeep. The ESTYMACJA program and the Biot-Gassmann model were used to study the dependence between elastic parameters and saturating fluids (water and gas) recorded in wells. Series of calculations was carried out using a method of fluid substitution for various gas saturation. The applicability of seismic data for evaluating gas saturation of reservoir beds was assessed with the use of 1D modelling (synthetic seismograms) and 2D modelling (theoretical seismic section) calculated for different gas saturation. The proposed methodology can be used to identify low and high gas-saturated zones and contour the reservoir.

  11. 水平井扇区水泥胶结测井偏心校正技术%Eccentricity Correction Technique for Sector Cement Bond Logging in Horizontal Well

    Institute of Scientific and Technical Information of China (English)

    曾桂红

    2016-01-01

    水平井固井质量评价资料为压裂等储层增产改造方案的制定提供支持,在水平井段,扇区水泥胶结测井仪器重力作用存在向下偏心现象,导致测井响应值偏低、解释偏差大。针对这一问题,研究偏心模型下井孔声场分布,明确了偏心距与套管波幅度间的关系;分析测井声系空间排布特点,利用八扇区到时、幅度反演仪器偏心程度;形成了适用于扇区水泥胶结测井的水平井固井质量评价偏心校正技术。该技术在南272‐平××井等81口水平井中应用,测井解释结果的准确性得到提高。%Well cementing quality evaluation data of the horizontal well is to provide support for the development of reservoir stimulation plan .In horizontal well section ,there is downward eccentricity due to the gravity effect of the sector cement bond logging instrument ,w hich leads to the low response value and large deviation of interpretation .To solve this problem ,the acoustic field distribution in the borehole is studied ,and the relationship between the eccentricity and the casing wave amplitude is defined .Inversed is the instrument eccentricity by the signal time and amplitude from the eight receivers on the basis of the acoustic spatial characteristics analysis .An eccentric correction technique is developed for the evaluation of the horizontal well cementing quality of the sector cement bond log ,which is applied to 81 wells including N272‐P × × ,and the accuracy of well logging interpretation is improved .

  12. Traitement des diagraphies acoustiques. Deuxième partie : séparation des ondes en diagraphie acoustique Full-Waveform Acoustic Data Processing. Second Part: Wave Separation in Acoustic Well Logging

    Directory of Open Access Journals (Sweden)

    Gavin P.

    2006-11-01

    'ambiguïté sur l'origine des réflexions. The fule waveforms recorded by an array of receivers in a borehole sonic tool contain a set of waves that can be fruitfully used to obtain detailed information about the nearborehole lithology and structure. Each wave contains information that can be disturbed by the presence of the other waves. The great amount of full-waveform sonic data leads geophysicists and log analysts to implement algorithms for separating waves. The log analyst must pay attention to the choice of parameters for acquisition. The acoustic data must be recorded with well suited spatial and temporal sampling-rates to avoid spatial and temporal aliasings. The efficiency of the wave-separation algorithms depends on the choice of acoustic data gathers. Acoustic data are sorted either in a common-shot gather or in a constant-offset gather. The wave separation filters commonly used are apparent velocity filters. Less usual filters are a Wiener filter and a spectral matrix filter. The efficiency of an apparent velocity filter is enhanced by application of spectrum equalization. The signal to noise ratio is enhanced by spectral matrix filtering. We describe different processing sequences applied to a set of field examples. First field example: full-waveform sonic data in a vertical wellFull-waveform sonic data were acquired in a vertical well drilled in an anticline structure used for underground gas storage by Gaz de France. The sonic tool used was a Schlumberger Dipole Imaging tool. This tool is an eight-receiver/three-transmitter device. The receiver section contains eight dipole-monopole stations spanning 3. 5 ft, each station spaced 6 inches (15 cm from its neighbor. The distance between the monopole transmitter and the first receiver station is 9 ft. The source was fired at equal spacings of 6 inches throughout the open hole section. For this experiment, the monopole transmitter was activated with a low frequency pulse for the purpose of generating low frequency

  13. The Application of Electric Imaging Logging Data in Horizontal Wells of A Certain Oilifeld%电成像测井资料在某油田水平井中的应用

    Institute of Scientific and Technical Information of China (English)

    付元强; 林文锋; 欧朝阳

    2015-01-01

    The heterogeneity and anisotropy of carbonate rock strata increases the difficulties of carbonate reservoir exploration&production. Besides possessing the characteristics of carbonate reservoir, a certain oilfield has reservoir fluid as high-density and high-viscosity heavy oil (average API specific weight of crude oil is 12.1). Routine logging items cannot effectively evaluate carbonate heavy oil fracture reservoir. Based on setting up illustrative model and optimizing processing software, electric imaging logging data acquired relatively good geological application results in horizontal wells.%碳酸盐岩地层的非均质性和各向异性,增加了碳酸盐岩油气藏勘探和开发的难度。某油田除了具有碳酸盐岩油藏特性以外,储层流体为高密度、高黏度稠油(原油平均API度为12.1)。常规测井项目已经不能有效地评价碳酸盐岩的稠油裂缝储层,通过建立解释模型、完善处理软件,使电成像测井资料在水平井中取得了较好的地质应用效果。

  14. Bore hole image well logging technique

    Energy Technology Data Exchange (ETDEWEB)

    Koh, Young Kwon; Kim, Geon Young; Bae, Dae Seok; Kim, Kyung Su; Ryu, Ji Hoon; Park, Kyung Woo; Ji, Sung Hoon

    2009-08-15

    As one of the investigation method which the underground geological features is direct drill investigation geological features condition of underground directness it will can confirm visually there is a strong point but the drill nose in compliance with war potential or a shock from the digging through process which it knows the orientation scattering, or, the capital where the destruction action which is mechanical will accompany it will be, also to the case where the ground condition is defective the nose Oh there is a possibility of being difficult also oneself getting to the evaluation which ground is accurate with being difficult, it operated and it was come. As the method which solves like this problem drill worker image photographing which is the possibility of getting the burn was introduced in about the drill worker wall. Drill worker image photographing it will be able to classify with 3 kind of electricity, the sound wave and optical science etc. on a large scale and these people are controlled and respectively amplitude and staring reaction of electric resistivity reaction and the sound wave, in order for the pixel price which digitizes optical science photograph etc. to confront clearly in spatial location it will be able to provide information concretely about rock floor etc., discontinuity surface situation and of the public wall travelling and inclination and the clearance

  15. Application and outlook of well logging in coal bed methane development and exploration%浅析煤层气勘探开发测井技术应用及发展

    Institute of Scientific and Technical Information of China (English)

    金力钻; 孙玉红; 王海平

    2015-01-01

    在煤层气的勘探开发中测井技术发挥着重要的作用,是煤层识别、煤层特性分析、煤层气评价等不可缺少的重要手段。本文对煤层气勘探开发测井技术发展趋势进行阐述,分析了现阶段存在的问题。%The well logging technology plays a very important role in exploration and development of coal-bed methane, which is indispensable in identification, properties analysis and evaluation of the coal bed. The development of this technology for coal-bed methane and problems exist are presented in the paper.

  16. Study on Well-logging Patent Retrieval Strategy and Construction of Subdatabase%测井专利检索策略研究及二级数据库建设

    Institute of Scientific and Technical Information of China (English)

    杨兴琴

    2011-01-01

    Construction of the well-logging patent database is objected to provide statistic data to the industry patent analysis. The author had made logging patents retrieval strategies consisted of key words and 284 subgroups from 12 subclasses selected from the International Patent Classification (IPC) and retrieved patents from patent databases of the European Patent Office, the World Intellectual Property Organization, and state intellectual property offices of China, United States of American, United Kingdom, France, Germany, Japan and Swaziland with time range from 1990 to 2010. The construction of international patent database service platform and 3 special subdatabases based on the patent analysis system provides detailed patent data to the industry patent study and make suggestions for the well-logging technology research and development.%建立测井专利数据库的目的是为测井技术专利分析提供统计数据.在广泛的测井技术背景调研工作基础上,制定了涉及国际专利分类号(IPC)12个小类284个小组的测井专利检索策略,以中、美、英、法、德、日、瑞士、欧洲专利局和世界知识产权组织等专利审查机构的专利数据库为数据源,对1990~2010年国内外测井专利进行检索.在专利分析系统的基础上,建立了1个中外测井专利数据服务平台和3个二级专利数据库,为测井专利分析提供了详细的专利数据,为测井技术科研开发决策提供了参考.

  17. 川东北碳酸岩储层测井资料的几点认识%A few understanding about the well logging data of carbonate rock reservoir in Northeast Sichuan

    Institute of Scientific and Technical Information of China (English)

    王煊

    2012-01-01

    Compared with the traditional sand/shale formation, the formation in Northeast Sichuan is characterized by high resistivity ,low sonic differential time (SDT) and low natural gamma ray (GR). The quality of well log is influenced by many factors, which result in the complexity in reservoir division and fluid property interpretation. On the basis of obser- vation data, the influencing factors of observed values and differences of the well log were analyzed one by one. These influ- encing factors are consist of borehole size, fissure, lithological character, mud filtrate, formation water resistivity, invasion depth, and so on. In addition, the geological application of the crossed dipoles is synthetically expounded.%与传统砂泥岩地层相比,川东北地区地层常以高电阻率、低声波时差、低自然伽玛为特征。影响测井曲线质量的因素很多,由此造成了储层划分和流体性质解释的难度。结合实测资料,对影响曲线测量值和差异的各种因素逐一进行了分析,这些影响因素包括井眼大小、裂缝、岩性、泥浆滤液和地层水电阻率、侵入深度等。并对交叉偶极子的地质应用进行了综合阐述。

  18. Geothermal potential of northern Bavaria: Analysis of geothermal resources by evaluation of geophysical temperature logs in drinking water wells and deep wells; Geothermisches Potential Nordbayerns - Untersuchungen der geothermischen Verhaeltnisse durch Auswertung geophysikalischer Temperaturmessungen in Trinkwasser- und Tiefbohrungen

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, W.; Udluft, P. [Lehr- und Forschungsbereich Hydrogeologie und Umwelt, Inst. fuer Geologie, Wuerzburg Univ. (Germany)

    1997-12-01

    The geothermal potential of northern Bavaria was investigated. Thermal water in the lower heat range may be used, e.g., for space heating, bath heating and agricultural purposes. Geophysical data were obtained from a number of drinking water wells with a depth of less than 150 m and a few deep wells of more than 150 m. The data are to serve as a decision aid for potential users of geothermal energy and reduce the exploration risk. (orig.) [Deutsch] Zielsetzung des Forschungsvorhabens ist die Bewertung des geothermischen Potentials Nordbayerns im Hinblick auf die Nutzung von Tiefenwasser zur Gewinnung von hydrothermaler Energie. Niedrigthermale Tiefenwaesser bieten sich z.B. als Energietraeger fuer Raumwaerme, Baederheizung and landwirtschaftliche Nutzung an. Die geothermischen Daten liegen in Form von geophysikalischen Temperaturmessungen aus zahlreichen Trinkwasserbohrungen mit weniger als 150 m Bohrtiefe und einigen Tiefbohrungen mit mehr als 150 m Bohrtiefe vor. Die Bewertung des geothermischen Potentials Nordbayerns soll als Planungsgrundlage fuer potentialle Erdwaermenutzer dienen und zu einer Minimierung des Explorationsrisikos beitragen. (orig.)

  19. http Log Analysis

    DEFF Research Database (Denmark)

    Bøving, Kristian Billeskov; Simonsen, Jesper

    2004-01-01

    This article documents how log analysis can inform qualitative studies concerning the usage of web-based information systems (WIS). No prior research has used http log files as data to study collaboration between multiple users in organisational settings. We investigate how to perform http log...... analysis; what http log analysis says about the nature of collaborative WIS use; and how results from http log analysis may support other data collection methods such as surveys, interviews, and observation. The analysis of log files initially lends itself to research designs, which serve to test...... hypotheses using a quantitative methodology. We show that http log analysis can also be valuable in qualitative research such as case studies. The results from http log analysis can be triangulated with other data sources and for example serve as a means of supporting the interpretation of interview data...

  20. http Log Analysis

    DEFF Research Database (Denmark)

    Bøving, Kristian Billeskov; Simonsen, Jesper

    2004-01-01

    This article documents how log analysis can inform qualitative studies concerning the usage of web-based information systems (WIS). No prior research has used http log files as data to study collaboration between multiple users in organisational settings. We investigate how to perform http log...... analysis; what http log analysis says about the nature of collaborative WIS use; and how results from http log analysis may support other data collection methods such as surveys, interviews, and observation. The analysis of log files initially lends itself to research designs, which serve to test...... hypotheses using a quantitative methodology. We show that http log analysis can also be valuable in qualitative research such as case studies. The results from http log analysis can be triangulated with other data sources and for example serve as a means of supporting the interpretation of interview data...

  1. INTERPRETATION CORRECTION OF THE OXYGEN ACTIVATED WELL LOGGING UNDER THE CONDITION OF OIL-WATER TWO-PHASE FLOWS OF HORIZONTAL WELLS%水平井油水两相流条件下氧活化测井解释校正

    Institute of Scientific and Technical Information of China (English)

    梁庆宝

    2012-01-01

    由于脉冲中子氧活化测井在水平井油水两相流条件下测量结果的相对误差随着含水率的减小而增大,因此有必要研究氧活化测井解释校正方法.根据放射性衰减规律以及物质对伽马射线的吸收规律,分析了理想测量条件下井内介质含水率对测量结果的影响,利用函数回归方法对水平井油水两相流条件下脉冲中子氧活化测井的解释结果进行了校正,并给出了与含水率相关的解释结果校正公式.当井内为油水两相流体时,采用该方法能够有效提高氧活化测井的解释精度.%Due to the deterioration of the relative errors of the measured results of the oxygen activated well logging under the conditions of oil-water two-phases flow in horizontal well with the decrease of the water cut, it is necessary to study on the correcting method of the above well logging interpretation. According to the laws of both radioactive decay and the absorption of gamma ray by substances, the influences of the water cuts of the downhole media on the measured results under the ideal operating conditions are analyzed. With the help of function regression method, the well logging interpretation results are corrected for the horizontal well in oil-water two-phase flows. In addition, the correcting formula of the interpretation results relating with the water cuts is presented. When there are two-phase oil-water flows in the well, the method can effectively improve the interpretation accuracy of oxygen activation well logging.

  2. Log N-log S in inconclusive

    Science.gov (United States)

    Klebesadel, R. W.; Fenimore, E. E.; Laros, J.

    1983-01-01

    The log N-log S data acquired by the Pioneer Venus Orbiter Gamma Burst Detector (PVO) are presented and compared to similar data from the Soviet KONUS experiment. Although the PVO data are consistent with and suggestive of a -3/2 power law distribution, the results are not adequate at this state of observations to differentiate between a -3/2 and a -1 power law slope.

  3. CNPC makes major breakthrough in array lateral logging technology

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    On October 12, 2011, the array lateral logging tool independently developed by CNPC Well Logging Company was successfully put to use at two production wells at Changqing Oilfield, obtaining high quality logging information. CNPC becomes the second company after Schlumberger in the world to master the array lateral logging technology, which can effectively identify layers as thin as 0.3 meter.

  4. 基于BP神经网络的测井资料预测岩石热导率%Prediction of Thermal Conductivity of Rocks Through Geophysical Well Logs Based on BP Neural Network

    Institute of Scientific and Technical Information of China (English)

    蒋海燕; 施小斌; 杨小秋; 石红才

    2012-01-01

    In order to obtain thermal conductivity of rocks at the depth where no core is available, we build ua prediction model for thermal conductivity based on BP neural networks with sonic, density, neutron porosity, resistivity, gamma ray as input. The prediction model needs short estimating time without any more lithological composition data, therefore it has more and wider applications than the empirical formula only influenced by one or several physical parameters. The test results from the test samples and 1144A, 1146A, 1148A well logs show that the error given by our model is less than the maximum permissible error of thermal conductivity measurement under laboratory conditions. This model provides a new way for obtaining thermal conductivity of rocks at the depth where has no core but has the related geophysical well logs.%为了获取无岩心深度段的岩石热导率,建立基于BP神经网络的热导率预测模型.根据声波、密度、中子、电阻率、自然伽马等5种测井响应预测岩石热导率,其模型计算所需时间较短,不需要岩性组分资料,比只考虑1种或其中几种物理参数影响的经验公式适用范围更广.对检验样本以及位于南海的1144A井、1146A井、1148A井等3口大洋科学钻探ODP(Ocean Drilling Program)钻孔的热导率预测结果表明,模型预测的热导率误差低于实验室岩石热导率测试的最大允许误差.该热导率预测模型为获取没有岩心的上述5种测井响应的深度段的岩石热导率提供了一种新途径.

  5. Quality control for quantitative geophysical logging

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sang Kyu; Hwang, Se Ho; Hwang, Hak Soo; Park, In Hwa [Korea Institute of Geology Mining and Materials, Taejon (Korea)

    1998-12-01

    Despite the great availability of geophysical data obtained from boreholes, the interpretation is subject to significant uncertainties. More accurate data with less statistical uncertainties should require an employment of more quantitative techniques in log acquisition and interpretation technique. The long-term objective of this project is the development of techniques in both quality control of log measurement and the quantitative interpretation. In the first year, the goals of the project will include establishing the procedure of log acquisition using various tests, analysing the effect of logging velocity change on the logging data, examining the repeatability and reproducibility, analyzing of filtering effect on the log measurements, and finally the zonation and the correlation of single-and inter-well log data. For the establishment of logging procedure, we have tested the multiple factors affecting the accuracy in depth. The factors are divided into two parts: human and mechanical. These factors include the zero setting of depth, the calculation of offset for the sonde, the stretching effect of cable, and measuring wheel accuracy. We conclude that the error in depth setting results primarily from human factor, and also in part from the stretching of cable. The statistical fluctuation of log measurements increases according to increasing the logging speed for the zone of lower natural gamma. Thus, the problem related with logging speed is a trifling matter in case of the application of resources exploration, the logging speed should run more slowly to reduce the statistical fluctuation of natural gamma with lithologic correlation in mind. The repeatability and reproducibility of logging measurements are tested. The results of repeatability test for the natural gamma sonde are qualitatively acceptable in the reproducibility test, the errors occurs in logging data between two operators and successive trials. We conclude that the errors result from the

  6. Mud Logging; Control geologico en perforaciones petroliferas (Mud Logging)

    Energy Technology Data Exchange (ETDEWEB)

    Pumarega Lafuente, J.C.

    1994-12-31

    Mud Logging is an important activity in the oil field and it is a key job in drilling operations, our duties are the acquisition, collection and interpretation of the geological and engineering data at the wellsite, also inform the client immediately of any significant changes in the well. (Author)

  7. LHCb: Universal Logging System for LHCb

    CERN Multimedia

    Nikolaidis, F; Garnier, J-C; Neufeld, N

    2010-01-01

    In a large-scale IT infrastructure such as the LHCb Online system many applications are running on thousands of machines producing many GBs of logs every day. Although most of the logs are just routine logs, some of them may indicate an attack, a malfunction or provide vital debugging information. Due to their volume only automatisation of the analysis of the logs can provide us with an efficient way to handle all of these logs, ensuring that even the most rare logs will be processed. We present a centralized logging system which allow us to do in-depth analysis of every log. The description of the architecture includes information from how we integrate logging from many devices to a centralized server using syslog and in particular how a correlation can indicate an attack. Special emphasis is given both to security monitoring as well as to the logs that indicate developing malfunctions. To secure our network we have deployed the most known of HIDS, NIDS , LIDS (Host , Network, Log intrusion detection). Each ...

  8. Recommandations essentielles de sécurité relatives au travail du personnel des laboratoires géologiques de chantier Essential Safety Recommendations Concerning Work by Personnel in Well Site Mud Logging Units

    Directory of Open Access Journals (Sweden)

    Chambre Syndicale du Pétrole

    2006-11-01

    Full Text Available Le personnel travaillant dans les cabines géologiques sur chantiers de forage doit respecter des règles de sécurité pour la prévention des accidents et doit connaître nécessairement les consignes à suivre en cas de danger. Ces recommandations sont relatives à l'installation des cabines géologiques et aux problèmes créés par leur équipement très diversifié, comprenant notamment de nombreux capteurs dispersés sur le chantier et leur réseau de câbles de liaison. Huit annexes rappellent les risques inhérents à la présence d'hydrogène sulfuré et les conditions d'utilisation des appareils de protection, les problèmes liés aux fours à micro-ondes éventuellement installés, ceux liés à la présence de sources radioactives. Une large part de ces recommandations est consacrée au stockage, à la manipulation et à l'élimination des produits chimiques couramment présents dans les cabines. Dix-neuf fiches de prévention simplifiées rappellent les risques que ces produits chimiques font courir au personnel et précisent les premiers soins à appliquer. Les deux dernières annexes traitent de la définition des zones classées pour les forages à terre et les forages en mer. The personnel working in mud logging units at well sites must respect safety rules for the prevention of accidents and must know the instructions to be followed in case of danger. These recommendations concern the installation of logging units and the problems created by the highly diversified equipment in such units, including in particular numerous sensors scattered around the site and the network of cables linking the sensors to the unit. Eight appendixes review the risks inherent in the presence of hydrogen sulfide and the conditions for using protective equipment, the problems linked to any microwave ovens that may be installed, and the problems linked to the presence of radioactive sources. A large portion of these recommen-dations is devoted to

  9. MDT测井技术在LG地区多井解释中的应用%Application of MDT logging technique in multi-well interpretation in the LG area

    Institute of Scientific and Technical Information of China (English)

    陈育勤; 石红梅; 华永川

    2009-01-01

    After the industrial gas flow was obtained in the exploratory well LG1 in the LG area, several other wells were successively drilled around this well. It is urgent to understand the lateral variation of reservoirs, vertical distribution of gas and water layers and the location of gas-water contact. Therefore, the MDT logging was carried out in over 10 exploratory wells and appraisal wells in the LG area to define the relationship among various gas reservoirs of reef and beach facies in the Permian Changxing Formation and that among gas reservoirs of oolitic beach facies in the Triassic Feixianguan Formation. The following results were obtained. For the reservoirs of oolitic beach facies in the Feixianguan Formation, the wells LG1, LG001-1, LG001-3 and LG001-6 share the same pressure system, while the wells LG2, LG3 and LG6 belong to different pressure systems. In contrast, for the reservoirs of reef and beach facies in the Changxing Formation, the wells LG1 and LG2 do not belong to the same pressure system, the wells LG001-1 and LG001-3 share the same pressure system, the wells LG12 and LG28 also share the same pressure system, while both wells LG8 and LG11 have a separate pressure system. These results provide direct basis for single well formation pressure analysis, identification of gas and water layers, pressure system analysis as well as later reserve estimation and development planning.%LG地区的预探井钻获工业气流后,在该井周围相继钻探了多口井,地质上迫切需要了解储层在横向上的变化情况、气水层在纵向上分布状况和气水界面等.为此,对LG地区10多口预探井及评价井进行了MDT地层测试,较好地解释了二叠系长兴组各个礁滩气藏以及三叠系飞仙关组各个鲕滩气藏之间的关系.研究表明:飞仙关组鲕滩储层中,LG1井与LG001-1、LG001-3、LG001-6井等属同一压力系统,而与LG2井、LG3井和LG6井为不同的压力系统;长兴组礁滩储层中,LG1井与LG2

  10. Logging data representation based on XML

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    As an open standard of data representation, XML breathes new energy to the Web application and the network computing. The development, advantage and status of XML and some standards relating to XML are reviewed. In addition, the authors put forward a method representing logging data and using UML language to establish the conceptual and logical model of logging data; using a logging data, explain how to establish the model as well as how to use XML to display and process geology data.

  11. Power to the logs!

    CERN Document Server

    CERN. Geneva; MACMAHON, Joseph

    2015-01-01

    Are you tired of using grep, vi and emacs to read your logs? Do you feel like you’re missing the big picture? Does the word "statistics" put a smile on your face? Then it’s time to give power to the logs!

  12. INTEGRATED APPROACH FOR THE PETROPHYSICAL INTERPRETATION OF POST- AND PRE-STACK 3-D SEISMIC DATA, WELL-LOG DATA, CORE DATA, GEOLOGICAL INFORMATION AND RESERVOIR PRODUCTION DATA VIA BAYESIAN STOCHASTIC INVERSION

    Energy Technology Data Exchange (ETDEWEB)

    Carlos Torres-Verdin; Mrinal K. Sen

    2004-03-01

    The present report summarizes the work carried out between September 30, 2002 and August 30, 2003 under DOE research contract No. DE-FC26-00BC15305. During the third year of work for this project we focused primarily on improving the efficiency of inversion algorithms and on developing algorithms for direct estimation of petrophysical parameters. The full waveform inversion algorithm for elastic property estimation was tested rigorously on a personal computer cluster. For sixteen nodes on the cluster the parallel algorithm was found to be scalable with a near linear speedup. This enabled us to invert a 2D seismic line in less than five hours of CPU time. We were invited to write a paper on our results that was subsequently accepted for publication. We also carried out a rigorous study to examine the sensitivity and resolution of seismic data to petrophysical parameters. In other words, we developed a full waveform inversion algorithm that estimates petrophysical parameters such as porosity and saturation from pre-stack seismic waveform data. First we used a modified Biot-Gassmann equation to relate petrophysical parameters to elastic parameters. The transformation was validated with a suite of well logs acquired in the deepwater Gulf of Mexico. As a part of this study, we carried out a sensitivity analysis and found that the porosity is very well resolved while the fluid saturation remains insensitive to seismic wave amplitudes. Finally we conducted a joint inversion of pre-stack seismic waveform and production history data. To overcome the computational difficulties we used a simpler waveform modeling algorithm together with an efficient subspace approach. The algorithm was tested on a realistic synthetic data set. We observed that the use of pre-stack seismic data helps tremendously to improve horizontal resolution of porosity maps. Finally, we submitted four publications to refereed technical journals, two refereed extended abstracts to technical conferences

  13. On log surfaces

    CERN Document Server

    Fujino, Osamu

    2012-01-01

    This paper is an announcement of the minimal model theory for log surfaces in all characteristics and contains some related results including a simplified proof of the Artin-Keel contraction theorem in the surface case.

  14. Design for a new type of flowmeter based on fiber optic interferometer for oil well logging%应用于石油测井的新型光纤干涉流量计的研究

    Institute of Scientific and Technical Information of China (English)

    王昌

    2012-01-01

    In the oil well logging,fluid flow is an extremely important parameter which determines the transmission characteristics of the oil production.Real-time monitoring of fluid flow parameter provides a scientific basis for the oil and gas optimization exploration and the increase of reservoir recovery.A new type of non-intrusive flowmeter based on fiber optic interferometer is proposed.The pipe′s vibration is induced by turbulent flow and the fiber optic sensors wrapped closely around the outside wall of pipe are used to sense the information of vibration.The frequency characteristics of the pipe′s vibration signals are found,and the relationship between the standard deviation of pipe wall′s vibration induced by fully developed turbulence and the mean flow rate is determined.The experiment has accomplished flow monitoring whose range is from 5 m3/h to 60 m3/h,and the measurement accuracy is±5%FS.It provides a good basis for further monitoring of the small flow.%提出一种新型非浸入式测量光纤干涉流量计,当流体流过管壁时可由湍流产生振动,紧密缠绕在油管外壁的光纤能够感应振动信息,通过管壁振动频率特性范围内确定出的由湍流诱发管壁振动加速度脉动值标准方差与平均流量的量化关系,即可求解出相应的流量。目前实验完成了5~60m3/h的较大流量量程的监测,测量精度为±5%FS,为下一步进行小流量量程监测提供良好的基础。

  15. Slim hole logging in shallow boreholes

    Directory of Open Access Journals (Sweden)

    R. Monnet

    2000-06-01

    Full Text Available While well logging, a continuous recording of the physical parameters down a borehole, is employed systematically in petroleum exploration, its application in environmental prospections, such as hydrogeology or civil engeering, has been very limited. This deficiency is partly due to the fact that logging probes used in this kind of boreholes are generally not calibrated and the results are more or less qualitative. The purpose of this lecture is to show that it is possible to calibrate these tools in order to obtain quantitative results, to make available to geologists, engineers and technicians engaged in shallow exploration, the information required for effectively applying the well-logging method.

  16. NMR logging apparatus

    Energy Technology Data Exchange (ETDEWEB)

    Walsh, David O; Turner, Peter

    2014-05-27

    Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

  17. NMR logging apparatus

    Science.gov (United States)

    Walsh, David O; Turner, Peter

    2014-05-27

    Technologies including NMR logging apparatus and methods are disclosed. Example NMR logging apparatus may include surface instrumentation and one or more downhole probes configured to fit within an earth borehole. The surface instrumentation may comprise a power amplifier, which may be coupled to the downhole probes via one or more transmission lines, and a controller configured to cause the power amplifier to generate a NMR activating pulse or sequence of pulses. Impedance matching means may be configured to match an output impedance of the power amplifier through a transmission line to a load impedance of a downhole probe. Methods may include deploying the various elements of disclosed NMR logging apparatus and using the apparatus to perform NMR measurements.

  18. Log4J

    CERN Document Server

    Perry, Steven

    2009-01-01

    Log4j has been around for a while now, and it seems like so many applications use it. I've used it in my applications for years now, and I'll bet you have too. But every time I need to do something with log4j I've never done before I find myself searching for examples of how to do whatever that is, and I don't usually have much luck. I believe the reason for this is that there is a not a great deal of useful information about log4j, either in print or on the Internet. The information is too simple to be of real-world use, too complicated to be distilled quickly (which is what most developers

  19. Questa Baseline and Pre-Mining Ground-Water Quality Investigation 15.-Methods of Phase II and III Well Installation and Development and Results of Well Logging, Hydraulic Testing, and Water-Level Measurements in the Red River Valley, New Mexico, 2002-04

    Science.gov (United States)

    Blanchard, Paul J.; Bartolino, James R.; Donohoe, Lisa C.; McAda, Douglas P.; Naus, Cheryl A.; Morin, Roger H.

    2007-01-01

    In April 2001, the U.S. Geological Survey and the New Mexico Environment Department began a cooperative study to infer the pre-mining ground-water chemistry at the Molycorp molybdenum mine site in the Red River Valley of north- central New Mexico. This report is one in a series of reports that can be used to determine pre-mining ground-water conditions at the mine site. Weathering of hydrothermally altered bedrock in the study area has resulted in steep, highly erosive, and sparsely vegetated scar areas that are clearly visible from the ground and in aerial photographs. Runoff from intense summer rainfall over tributary drainages containing scar areas can transport large quantities of sediment and form debris fans where these tributaries join the Red River. Twenty-nine observation wells were installed in three phases as part of this study in the Red River Valley and tributary drainages. Eight Phase II observation wells were drilled using an air-rotary/hammer rig. Three Phase II and 10 phase III small-diameter wells were installed using a direct-push rig. Lithologic logs were recorded for all eight Phase II drilled wells. Borehole geophysical logging (including natural gamma, induction, and single-detector neutron) was conducted in three Phase II wells. Aquifer tests conducted during 2003 to estimate the hydraulic properties of debris-flow and Red River alluvial deposits in and near Straight Creek included a flow-meter survey, slug tests, and a pumping test. Results of a flow-meter survey in well SC-7A indicated that about 77 percent of the water entered the well from a 10-foot-thick zone near the top of the screened interval and about 23 percent of the water entered the well from a 15-foot-thick zone near the bottom of the screened interval. Slug tests, performed in 11 wells during June 3-5, 2003, indicated that the mean and median estimated hydraulic conductivities for debris-flow deposits were 15.25 and 15.35 feet per day, respectively, for bedrock were 0.12 and

  20. 麻黄山西探区淡水泥浆侵入电阻率测井特征分析及其应用%Analysis of the Features of Fresh Water Invaded Resistivity Well Logging in Mahuangshan's West Exploration Area and Its Application

    Institute of Scientific and Technical Information of China (English)

    赵永刚; 潘和平

    2012-01-01

    麻黄山西探区大部分井的泥浆矿化度小于地层水矿化度,导致淡水泥浆侵入,影响电阻率测井值,使利用测井资料评价油水层存在较大的技术难度.在分析麻黄山西探区淡水泥浆侵入电阻率测井特征的基础上,对电阻率测井系列进行了合理选择,论述了径向电阻率比值法,并采用径向电阻率比值法计算含水饱和度,测井解释结果与试油资料对比表明,解释效果好,符合率高.%The mud salinity is less than the formation water salinity in most wells of Mahuangshan s west exploration area, causing the invasion of freshwater mud. As a result, the data of resistivity well logging is influenced, and evaluating oil and water layers by logging data is rather difficult in techniques. This paper analyzes the features of fresh water invaded resistivity well logging in Mahuangshan's west exploration area, chooses the reasonable logging series, introduces the radial resistivity ration method, and uses the method to calculate the saturation. The comparison of logging interpretation result with the well testing data shows the interpretatino is effective and the coincidence rate is high.

  1. Logging on to Learn

    Science.gov (United States)

    Butler, Kevin

    2010-01-01

    A classroom lecture at Capistrano Connections Academy in Southern California involves booting up the home computer, logging on to a Web site, and observing a teacher conducting a PowerPoint presentation of that day's lesson entirely online. Through microphone headsets, students can watch on their home computers, respond to the teacher's questions,…

  2. Slim hole logging in shallow boreholes

    OpenAIRE

    Monnet, R.; L. Baron; Chapellier, D. M.

    2000-01-01

    While well logging, a continuous recording of the physical parameters down a borehole, is employed systematically in petroleum exploration, its application in environmental prospections, such as hydrogeology or civil engeering, has been very limited. This deficiency is partly due to the fact that logging probes used in this kind of boreholes are generally not calibrated and the results are more or less qualitative. The purpose of this lecture is to show that it is possible to calibrate these ...

  3. 有机碳测井评价方法在断陷盆地中的应用%Application of a Method for Calculating the Organic Carbon Content by Well Logs to Faulted Basins

    Institute of Scientific and Technical Information of China (English)

    孙建平; 刘洛夫; 庞雄奇; 宫广盛; 李凤君

    2005-01-01

    The source rock model used in this project was developed by French Petroleum Research Institute. The total organic carbon content was estimated primarily and directly by using continuous conventional logging curves (such as sonic and resistivity curves), which are calibrated through the laboratory analysis data of organic carbon of cores, cuttings or sidewall cores. Regional evaluations have been carried out in downwarping basins abroad. The Haila'er Basin is a faulted basin and the evaluation of such a basin is a new subject. On the basis of a regional evaluation method for the downwarping basins, a new method suitable to faulted basins was developed. The effect is satisfactory when this new method is applied to the Wu'erxun Sag and the Bei'er Sag.

  4. Interpretation of digital well-logging for "three zones" in coal mine area%数字测井资料对矿区“三带”地层的解释及应用

    Institute of Scientific and Technical Information of China (English)

    韩绪山; 张景考

    2001-01-01

    利用数字测井资料对矿区工作面上覆地层的冒落带、裂隙带和弯曲沉降带进行系统的综合解释,确定其发育情况,对指导矿区的安全生产、开采范围的确定及开采煤柱留舍颇有益处。%It is presented that the method of systematic and comprehensive interpretation on caving,fractured and continuous depressing zones overlying the coal faces by advantages of the digital logging data,determination of their development conditions.It should be beneficial for mine safety production,identifcation of mining scope preservation of coal pillars.

  5. Analysis of fractures along a borehole axis at a geothermal well. Preliminary study for interpretation of 3D stress field using logging data. Chinetsusei ni okeru koseijiku ni sou fracture no kaiseki. Kenso data wo riyoshita 3 jigen oryokuba kaiseki no yobiteki hyoka

    Energy Technology Data Exchange (ETDEWEB)

    Okabe, T.; Shinohara, N.; Takasugi, S. (GERD Geothermal Energy Research and Development Co. Ltd., Tokyo (Japan)); Hayashi, K. (Tohoku University, Sendai (Japan). Institute of Fluid Science)

    1994-05-01

    Logging and analysis by BHTV and FMI were made in order to detect and evaluate the fracture before and after the hydraulic crushing of geothermal well. As a result of BHTV logging, the number of fractures detected increased before and after its hydraulic crushing. Though artificially generated, new open cracks were not confirmed at approximate depths of mud water leakage. That leakage which was generated by the hydraulic crushing was judged attributable to the opening of originally existing natural cracks. The FMI logging which electrically surveys the borehole wall can easily give information about the stratification planes. Many fractures were detected due to stratification planes which traveled west-northwestward with a southwestward dip of 20[degree] at the depth of 950 to 1100m. It was judged that some fractures leaking the mud water had largely depended upon the intrusive orientation of andesite and natural cracks during the hydraulic crushing, and lay on an intrusive boundary of andesite. The conclusion from the foregoing was that the evaluation of fracture, through logging by BHTV and FMI in advance, in the borehole is important for the hydraulic crushing. 3 refs., 7 figs.

  6. 测井、井间地震与地面地震数据联合约束下的地质统计学随机建模方法研究%A new geostatistical inversion and reservoir modeling technique constrained by well-log, crosshole and surface seismic data

    Institute of Scientific and Technical Information of China (English)

    杨锴; 艾迪飞; 耿建华

    2012-01-01

    Based on a geostatistical simulation method conditioned to well-log and crosshole seismic rays, a novel geostatistical reservoir inversion (modeling) technique constrained by well-log, crosshole and surface seismic data is presented. Compared with existing geostatistical inversion methods only the well-log and surface seismic data being honored, all related prior information include well-log, crosshole seismic data and surface seimismic data are honored in presented method. Thus the accuracy of geostatistical inversion/modeling is greatly improved and the uncertainty of inversion/modeling is reduced. The test on synthetic data proved the above points.%利用能够整合测井信息与井间地震信息的地质统计学随机模拟方法,结合传统的地质统计学反演思路,得到了一种能够同时整合测井、井间地震与地面地震三种先验信息的地质统计学反演与储层建模方法.由于井间射线信息、测井信息与地面地震数据在随机反演与建模过程当中都得到了尊重,因此与传统地质统计学反演仅利用了测井与地面地震数据相比,本文的地质统计学反演与建模方法更充分地利用了先验信息,有效提高了反演的精度,降低了随机建模中的多解性.基于理论数据的测试证实了上述观点.

  7. Design of analog signal separation in computerized well logging surface system%数控测井地面系统中模拟信号分离单元的设计

    Institute of Scientific and Technical Information of China (English)

    陈超波; 高嵩; 何宁; 袁晓伟

    2011-01-01

    在全面、细致地分析了井下仪器回传信号的类型、数据通信的特点基础上,测井仪器的回传的模拟信号均是低频信号,因此模拟信号分离单元电路采用压控电压源二阶低通滤波及电压跟随电路,可将低频模拟信号有效地分离出来。以磁记号信号为例,实验表明,模拟信号经过分离单元,滤除了高频干扰信号,为后期模拟量信号的采集处理提供了可靠保障。%By analyzing the types of return signals from the downhole instrument and the characteristics of data communications entirely, the analog signal of logging instrument back has low frequency. Then, the analog signal separation unit, which uses voltage-controlled voltage source order low pass filter and voltage follower circuits, can isolate the low-frequency signal effectively. For example, high-frequency interference signal in the magnetic signal has been removed by the analog signal separation unit. It can provide reliable guarantee for the late analog signal acquisition.

  8. China Offshore Oil Logging Technology

    Institute of Scientific and Technical Information of China (English)

    Duan Kang

    1996-01-01

    @@ China offshore oil logging business entered a faster developing stage sin-ce 1982 with the beginning of international cooperation in its offshore oil exploration. Nearly 90% of the logging expertises of China National Offshore Oil Corporation (CNOOC)are in China Offshore Oil Logging Company (COOLC), headquartered in Yanjiao, Hebei Province.

  9. Grid Logging: Best Practices Guide

    Energy Technology Data Exchange (ETDEWEB)

    Tierney, Brian L; Tierney, Brian L; Gunter, Dan

    2008-04-01

    The purpose of this document is to help developers of Grid middleware and application software generate log files that will be useful to Grid administrators, users, developers and Grid middleware itself. Currently, most of the currently generated log files are only useful to the author of the program. Good logging practices are instrumental to performance analysis, problem diagnosis, and security auditing tasks such as incident tracing and damage assessment. This document does not discuss the issue of a logging API. It is assumed that a standard log API such as syslog (C), log4j (Java), or logger (Python) is being used. Other custom logging API or even printf could be used. The key point is that the logs must contain the required information in the required format. At a high level of abstraction, the best practices for Grid logging are: (1) Consistently structured, typed, log events; (2) A standard high-resolution timestamp; (3) Use of logging levels and categories to separate logs by detail and purpose; (4) Consistent use of global and local identifiers; and (5) Use of some regular, newline-delimited ASCII text format. The rest of this document describes each of these recommendations in detail.

  10. Dynamic Planar Convex Hull with Optimal Query Time and O(log n · log log n ) Update Time

    DEFF Research Database (Denmark)

    Brodal, Gerth Stølting; Jakob, Riko

    2000-01-01

    The dynamic maintenance of the convex hull of a set of points in the plane is one of the most important problems in computational geometry. We present a data structure supporting point insertions in amortized O(log n · log log log n) time, point deletions in amortized O(log n · log log n) time...

  11. Selective Logging, Fire, and Biomass in Amazonia

    Science.gov (United States)

    Houghton, R. A.

    1999-01-01

    Biomass and rates of disturbance are major factors in determining the net flux of carbon between terrestrial ecosystems and the atmosphere, and neither of them is well known for most of the earth's surface. Satellite data over large areas are beginning to be used systematically to measure rates of two of the most important types of disturbance, deforestation and reforestation, but these are not the only types of disturbance that affect carbon storage. Other examples include selective logging and fire. In northern mid-latitude forests, logging and subsequent regrowth of forests have, in recent decades, contributed more to the net flux of carbon between terrestrial ecosystems and the atmosphere than any other type of land use. In the tropics logging is also becoming increasingly important. According to the FAO/UNEP assessment of tropical forests, about 25% of total area of productive forests have been logged one or more times in the 60-80 years before 1980. The fraction must be considerably greater at present. Thus, deforestation by itself accounts for only a portion of the emissions carbon from land. Furthermore, as rates of deforestation become more accurately measured with satellites, uncertainty in biomass will become the major factor accounting for the remaining uncertainty in estimates of carbon flux. An approach is needed for determining the biomass of terrestrial ecosystems. 3 Selective logging is increasingly important in Amazonia, yet it has not been included in region-wide, satellite-based assessments of land-cover change, in part because it is not as striking as deforestation. Nevertheless, logging affects terrestrial carbon storage both directly and indirectly. Besides the losses of carbon directly associated with selective logging, logging also increases the likelihood of fire.

  12. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    McGhan, V.L.

    1989-06-01

    The Site Characterization and Assessment Section of the Geosciences Department at Pacific Northwest Laboratory (PNL) has compiled a list of wells located on or near the Hanford Site. Information has been updated on wells existing from the days before construction of the Hanford Works to the present. This work was funded by the US Department of Energy (DOE). The list of wells will be used by DOE contractors who need condensed, tabular information on well location, construction, and completion dates. This report does not include data on lithologic logs and ground-water contamination. Moreover, the completeness of this list is limited because of new well construction and existing well modifications, which are continually under way. Despite these limitations, this list represents the most complete description possible of data pertaining to wells on or adjacent to the Hanford Site. 7 refs., 1 fig., 2 tabs.

  13. 声波测井压电振子温度性能一致性实验研究%Experimental Investigation on Temperature Performance Consistency of Piezoelectric Benders Used in Acoustic Well Logging

    Institute of Scientific and Technical Information of China (English)

    吴金平; 乔文孝; 车小花; 吴文河; 丁燕; 邓林

    2012-01-01

    新一代声波测井技术采用了相控圆弧阵作为声波辐射器,构成圆弧阵的压电振子的耐高温性能一致性是一项重要的技术指标.以相控圆弧阵所使用的阵元为例实验研究了压电振子的耐高温性能以及阻抗特性一致性随温度的变化.测试结果表明,压电振子的谐振频率和静态电容随着温度的升高而增大,而最大电导和脉冲响应幅度随着温度的升高而降低;压电振子的阻抗特性一致性随着温度的升高相对下降,150℃下相对变化量可控制在4%以内.将压电振子从高温环境冷却至常温27℃后,压电振子的阻抗特性具有可恢复性.经测试的压电振子的耐温指标能够达到150℃左右,且高温下阻抗特性一致性较好,能够满足井下高温环境的应用要求.%Since the acoustic phased arc array transmitter is used in the latest generation acoustic logging, the temperature-resistant consistency of benders which are employed to form arc array transmitter has become a key technical index. High temperature resistance and impedance characteristics consistency of benders, which vary with temperature, are investigated by experiments. Experimental results show that, as the temperature rises, the resonance frequency and shunt capacitance increase, but the maximum conductance and impulse response magnitude decrease. The relative variation is not greater than 4% in 150 ℃ although impedance characteristics consistency decrease slightly. With the temperature reducing to 27℃, impedance characteristics of benders are restorable. Finally, it is considered that the temperature index of benders tested can reach around 150 ℃, and they maintain relative good impedance characteristics consistency in high temperature, which fully satisfies application demands of downhole high temperature environment.

  14. Application of MRIL-WD (Magnetic Resonance Imaging Logging While Drilling) for irreducible water saturation, total reservoir, free-fluid, bound-fluid porosity measurements and its value for the petrophysical analysis of RT/RM data from the Shah Deniz well

    Science.gov (United States)

    Amirov, Elnur

    2016-04-01

    Sperry-Sun (Sperry Drilling Services) is the leader in MWD/LWD reliability, has developed the industry's first LWD NMR/MRIL-WD (nuclear magnetic resonance) tool. The MRIL-WD (magnetic resonance imaging logging-while-drilling) service directly measures the T1 component of hydrogen in subsurface rock units while drilling to obtain total reservoir porosity and to dissect the observed total porosity into its respective components of free fluid and bound fluid porosity. These T1 data are used to secure accurate total, free-fluid, capillary-bound water, and clay-bound water porosity of the reservoir sections which can be drilled in the several Runs. Over the last decade, results from Magnetic Resonance Imaging logs (NMR) have added significant value to petrophysical analysis and understanding by providing total, free-fluid and bound-fluid porosities, combined with fluid typing capabilities. With MRIL-WD very valuable Real-Time or Recorded Memory data/information is now available during or shortly after the drilling operation (formation properties measurement can be taken right after a drill bit penetration), while trip in and trip out as well. A key point in utilizing MRIL in an LWD environment is motion-tolerant measurements. Recent MRIL-WD logging runs from the Shah Deniz wells located in the Khazarian-Caspian Sea of the Azerbaijan Republic helped to delineate and assess hydrocarbon bearing zones. Acquired results demonstrate how MRIL data can be acquired while-drilling and provide reliable/high quality measurements. Magnetic Resonance Imaging logs at some developments wells have become a cornerstone in formation evaluation and petrophysical understanding. By providing total, free-fluid, and bound-fluid porosities together with fluid typing, MRIL results have significantly added to the assessment of reservoirs. In order to reduce NPT (Non-Productive Time) and save the rig operations time, there is always the desire to obtain logging results as soon as possible

  15. The X-ray log N-log S relation. [background radiation in extragalactic media

    Science.gov (United States)

    Boldt, Elihu

    1989-01-01

    Results from various surveys are reviewed as regards X-ray source counts at high galactic latitudes and the luminosity functions determined for extragalactic sources. Constraints on the associated log N-log S relation provided by the extragalactic X-ray background are emphasized in terms of its spatial fluctuations and spectrum as well as absolute flux level. The large number of sources required for this background suggests that there is not a sharp boundary in the redshift distribution of visible matter.

  16. Log-Determinant Divergences Revisited: Alpha-Beta and Gamma Log-Det Divergences

    Directory of Open Access Journals (Sweden)

    Andrzej Cichocki

    2015-05-01

    Full Text Available This work reviews and extends a family of log-determinant (log-det divergences for symmetric positive definite (SPD matrices and discusses their fundamental properties. We show how to use parameterized Alpha-Beta (AB and Gamma log-det divergences to generate many well-known divergences; in particular, we consider the Stein’s loss, the S-divergence, also called Jensen-Bregman LogDet (JBLD divergence, Logdet Zero (Bhattacharyya divergence, Affine Invariant Riemannian Metric (AIRM, and other divergences. Moreover, we establish links and correspondences between log-det divergences and visualise them on an alpha-beta plane for various sets of parameters. We use this unifying framework to interpret and extend existing similarity measures for semidefinite covariance matrices in finite-dimensional Reproducing Kernel Hilbert Spaces (RKHS. This paper also shows how the Alpha-Beta family of log-det divergences relates to the divergences of multivariate and multilinear normal distributions. Closed form formulas are derived for Gamma divergences of two multivariate Gaussian densities; the special cases of the Kullback-Leibler, Bhattacharyya, Rényi, and Cauchy-Schwartz divergences are discussed. Symmetrized versions of log-det divergences are also considered and briefly reviewed. Finally, a class of divergences is extended to multiway divergences for separable covariance (or precision matrices.

  17. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    Chamness, M.A.; Merz, J.K.

    1993-08-01

    Records describing wells located on or near the Hanford Site have been maintained by Pacific Northwest Laboratory and the operating contractor, Westinghouse Hanford Company. In support of the Ground-Water Surveillance Project, portions of the data contained in these records have been compiled into the following report, which is intended to be used by those needing a condensed, tabular summary of well location and basic construction information. The wells listed in this report were constructed over a period of time spanning almost 70 years. Data included in this report were retrieved from the Hanford Envirorunental Information System (HEIS) database and supplemented with information not yet entered into HEIS. While considerable effort has been made to obtain the most accurate and complete tabulations possible of the Hanford Site wells, omissions and errors may exist. This document does not include data on lithologic logs, ground-water analyses, or specific well completion details.

  18. Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

    Energy Technology Data Exchange (ETDEWEB)

    Gustafsson, Jaana; Gustafsson, Christer (Malaa Geoscience AB (Sweden))

    2010-01-15

    This report includes the data gained in BIPS logging performed at the Aespoe Hard Rock Laboratory. The logging operation presented here includes BIPS logging in the core drilled borehole KAS09. The objective for the BIPS logging was to observe the condition of KAS09 in order to restore the borehole in the hydrogeological monitoring programme.All measurements were conducted by Malaa Geoscience AB on October 9th 2009. The objective of the BIPS logging is to achieve information of the borehole including occurrence of rock types as well as determination of fracture distribution and orientation. This report describes the equipment used as well as the measurement procedures and data gained. For the BIPS survey, the result is presented as images. The basic conditions of the BIPS logging for geological mapping and orientation of structures are satisfying for borehole KAS09, although induced affects from the drilling on the borehole walls limit the visibility

  19. Core-log integration for a Saudi Arabian sandstone reservoir

    Energy Technology Data Exchange (ETDEWEB)

    Saha, S.; Al-Kaabi, A.U.; Amabeoku, M.O.; Al-Fossail, K.

    1995-10-01

    For a detailed characterization of a reservoir, core-log integration is essential. In this paper, data integration from logs and cores of a Saudi Arabian sandstone reservoir is discussed with particular attention to effects of clay on resistivity logs and water saturation. There are four sources of data, namely, core resistivity measurement, clay study from cores (XRD, CEC), spectral core gamma ray, and well logs. In order to generate continuous cation exchange capacity (CEC) with depth, spectral gamma ray measurements (both from core and downhole log) and CEC from cores and correlated. Q{sub v} (CEC per unit pore volume) values are calculated utilizing only well logs by applying Waxman-Smits equation in water bearing zone. Log derived Q{sub v} values from water zone were then correlated with porosity to generate Q{sub v} values in the oil column and compared with core derived Z{sub v}. Finally, data from well logs (porosity, resistivity and Q{sub v}) and cores (resistivity parameters m, n, and Q{sub v}) were integrated for more accurate water saturation calculation. The core-log correlation can be applied to other wells avoiding expensive core analysis, and the technique developed in this project can be used in other sandstone reservoirs.

  20. Minimal Log Gravity

    CERN Document Server

    Giribet, Gaston

    2014-01-01

    Minimal Massive Gravity (MMG) is an extension of three-dimensional Topologically Massive Gravity that, when formulated about Anti-de Sitter space, accomplishes to solve the tension between bulk and boundary unitarity that other models in three dimensions suffer from. We study this theory at the chiral point, i.e. at the point of the parameter space where one of the central charges of the dual conformal field theory vanishes. We investigate the non-linear regime of the theory, meaning that we study exact solutions to the MMG field equations that are not Einstein manifolds. We exhibit a large class of solutions of this type, which behave asymptotically in different manners. In particular, we find analytic solutions that represent two-parameter deformations of extremal Banados-Teitelboim-Zanelli (BTZ) black holes. These geometries behave asymptotically as solutions of the so-called Log Gravity, and, despite the weakened falling-off close to the boundary, they have finite mass and finite angular momentum, which w...

  1. Minimal log gravity

    Science.gov (United States)

    Giribet, Gaston; Vásquez, Yerko

    2015-01-01

    Minimal massive gravity (MMG) is an extension of three-dimensional topologically massive gravity that, when formulated about anti-de Sitter space, accomplishes solving the tension between bulk and boundary unitarity that other models in three dimensions suffer from. We study this theory at the chiral point, i.e. at the point of the parameter space where one of the central charges of the dual conformal field theory vanishes. We investigate the nonlinear regime of the theory, meaning that we study exact solutions to the MMG field equations that are not Einstein manifolds. We exhibit a large class of solutions of this type, which behave asymptotically in different manners. In particular, we find analytic solutions that represent two-parameter deformations of extremal Bañados-Teitelboim-Zanelli black holes. These geometries behave asymptotically as solutions of the so-called log gravity, and, despite the weakened falling off close to the boundary, they have finite mass and finite angular momentum, which we compute. We also find time-dependent deformations of Bañados-Teitelboim-Zanelli that obey Brown-Henneaux asymptotic boundary conditions. The existence of such solutions shows that the Birkhoff theorem does not hold in MMG at the chiral point. Other peculiar features of the theory at the chiral point, such as the degeneracy it exhibits in the decoupling limit, are discussed.

  2. Development of pulsed neutron uranium logging instrument

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Xin-guang, E-mail: wangxg@upc.edu.cn [School of Geosciences, China University of Petroleum, Qingdao 266580 (China); Engineering Research Center of Nuclear Technology Application (East China Institute of Technology), Ministry of Education, Nanchang 330013 (China); Liu, Dan [China Institute of Atomic Energy, Beijing 102413 (China); Zhang, Feng [School of Geosciences, China University of Petroleum, Qingdao 266580 (China)

    2015-03-15

    This article introduces a development of pulsed neutron uranium logging instrument. By analyzing the temporal distribution of epithermal neutrons generated from the thermal fission of {sup 235}U, we propose a new method with a uranium-bearing index to calculate the uranium content in the formation. An instrument employing a D-T neutron generator and two epithermal neutron detectors has been developed. The logging response is studied using Monte Carlo simulation and experiments in calibration wells. The simulation and experimental results show that the uranium-bearing index is linearly correlated with the uranium content, and the porosity and thermal neutron lifetime of the formation can be acquired simultaneously.

  3. Tectonic history in the Fort Worth Basin, north Texas, derived from well-log integration with multiple 3D seismic reflection surveys: implications for paleo and present-day seismicity in the basin

    Science.gov (United States)

    Magnani, M. B.; Hornbach, M. J.

    2016-12-01

    Oil and gas exploration and production in the Fort Worth Basin (FWB) in north Texas have accelerated in the last 10 years due to the success of unconventional gas production. Here, hydraulic fracturing wastewater is disposed via re-injection into deep wells that penetrate Ordovician carbonate formations. The rise in wastewater injection has coincided with a marked rise in earthquake rates, suggesting a causal relationship between industry practices and seismicity. Most studies addressing this relationship in intraplate regions like the FWB focus on current seismicity, which provides an a-posteriori assessment of the processes involved. 3D seismic reflection data contribute complementary information on the existence, distribution, orientation and long-term deformation history of faults that can potentially become reactivated by the injection process. Here we present new insights into the tectonic evolution of faults in the FWB using multiple 3D seismic reflection surveys in the basin, west of the Dallas Fort-Worth Metroplex, where high-volume wastewater injection wells have increased most significantly in number in the past few years. The datasets image with remarkable clarity the 3,300 m-thick sedimentary rocks of the basin, from the crystalline basement to the Cretaceous cover, with particular detail of the Paleozoic section. The data, interpreted using coincident and nearby wells to correlate seismic reflections with stratigraphic markers, allow us to identify faults, extract their orientation, length and displacements at several geologic time intervals, and therefore, reconstruct the long-term deformation history. Throughout the basin, the data show that all seismically detectable faults were active during the Mississippian and Pennsylvanian, but that displacement amounts drop below data resolution ( 7 m) in the post-Pennsylvanian deposits. These results indicate that faults have been inactive for at least the past 300 Ma, until the recent 2008 surge in

  4. Cased-hole log analysis and reservoir performance monitoring

    CERN Document Server

    Bateman, Richard M

    2015-01-01

    This book addresses vital issues, such as the evaluation of shale gas reservoirs and their production. Topics include the cased-hole logging environment, reservoir fluid properties; flow regimes; temperature, noise, cement bond, and pulsed neutron logging; and casing inspection. Production logging charts and tables are included in the appendices. The work serves as a comprehensive reference for production engineers with upstream E&P companies, well logging service company employees, university students, and petroleum industry training professionals. This book also: ·       Provides methods of conveying production logging tools along horizontal well segments as well as measurements of formation electrical resistivity through casing ·       Covers new information on fluid flow characteristics in inclined pipe and provides new and improved nuclear tool measurements in cased wells ·       Includes updates on cased-hole wireline formation testing  

  5. Console Log Keeping Made Easier - Tools and Techniques for Improving Quality of Flight Controller Activity Logs

    Science.gov (United States)

    Scott, David W.; Underwood, Debrah (Technical Monitor)

    2002-01-01

    At the Marshall Space Flight Center's (MSFC) Payload Operations Integration Center (POIC) for International Space Station (ISS), each flight controller maintains detailed logs of activities and communications at their console position. These logs are critical for accurately controlling flight in real-time as well as providing a historical record and troubleshooting tool. This paper describes logging methods and electronic formats used at the POIC and provides food for thought on their strengths and limitations, plus proposes some innovative extensions. It also describes an inexpensive PC-based scheme for capturing and/or transcribing audio clips from communications consoles. Flight control activity (e.g. interpreting computer displays, entering data/issuing electronic commands, and communicating with others) can become extremely intense. It's essential to document it well, but the effort to do so may conflict with actual activity. This can be more than just annoying, as what's in the logs (or just as importantly not in them) often feeds back directly into the quality of future operations, whether short-term or long-term. In earlier programs, such as Spacelab, log keeping was done on paper, often using position-specific shorthand, and the other reader was at the mercy of the writer's penmanship. Today, user-friendly software solves the legibility problem and can automate date/time entry, but some content may take longer to finish due to individual typing speed and less use of symbols. File layout can be used to great advantage in making types of information easy to find, and creating searchable master logs for a given position is very easy and a real lifesaver in reconstructing events or researching a given topic. We'll examine log formats from several console position, and the types of information that are included and (just as importantly) excluded. We'll also look at when a summary or synopsis is effective, and when extensive detail is needed.

  6. SNG-logs at Skjern

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C; Petersen, Jesper; Aage, Helle Karina

    1998-01-01

    Spectral Natural Gamma-ray logs have been run in two water supply borings at Skjern. The log data have been examined by a new technique - Noise Adjusted Singular Value Decomposition - in order to get a detailed and reliable picture of the distribution of uranium and thorium gamma-rays from heavy...

  7. Fates of trees damaged by logging in Amazonian Bolivia

    NARCIS (Netherlands)

    Shenkin, A.; Bolker, B.; Peña Claros, M.; Licona, J.C.; Putz, F.E.

    2015-01-01

    Estimation of carbon losses from trees felled and incidentally-killed during selective logging of tropical forests is relatively straightforward and well-documented, but less is known about the fates of collaterally-damaged trees that initially survive. Tree response to logging damage is an importan

  8. Rill erosion in burned and salvage logged western montane forests: Effects of logging equipment type, traffic level, and slash treatment

    Science.gov (United States)

    Wagenbrenner, J. W.; Robichaud, P. R.; Brown, R. E.

    2016-10-01

    Following wildfires, forest managers often consider salvage logging burned trees to recover monetary value of timber, reduce fuel loads, or to meet other objectives. Relatively little is known about the cumulative hydrologic effects of wildfire and subsequent timber harvest using logging equipment. We used controlled rill experiments in logged and unlogged (control) forests burned at high severity in northern Montana, eastern Washington, and southern British Columbia to quantify rill overland flow and sediment production rates (fluxes) after ground-based salvage logging. We tested different types of logging equipment-feller-bunchers, tracked and wheeled skidders, and wheeled forwarders-as well as traffic levels and the addition of slash to skid trails as a best management practice. Rill experiments were done at each location in the first year after the fire and repeated in subsequent years. Logging was completed in the first or second post-fire year. We found that ground-based logging using heavy equipment compacted soil, reduced soil water repellency, and reduced vegetation cover. Vegetation recovery rates were slower in most logged areas than the controls. Runoff rates were higher in the skidder and forwarder plots than their respective controls in the Montana and Washington sites in the year that logging occurred, and the difference in runoff between the skidder and control plots at the British Columbia site was nearly significant (p = 0.089). Most of the significant increases in runoff in the logged plots persisted for subsequent years. The type of skidder, the addition of slash, and the amount of forwarder traffic did not significantly affect the runoff rates. Across the three sites, rill sediment fluxes were 5-1900% greater in logged plots than the controls in the year of logging, and the increases were significant for all logging treatments except the low use forwarder trails. There was no difference in the first-year sediment fluxes between the feller

  9. Prediction of thermal conductivity of sedimentary rocks from well logs

    DEFF Research Database (Denmark)

    Fuchs, Sven; Förster, Andrea

    2014-01-01

    . A common procedure in the latter approach is the use of empirical relations between TC and different petrophysical properties. Although numerous prediction equations were developed in the past five decades, none of these seem to be universally applicable for all major types of sedimentary rocks (clastics...... parameters (i.e. thermal conductivity, density, hydrogen index, sonic interval transit time, gamma-ray response, photoelectric factor) of artificial mineral assemblages consisting 15 rock-forming minerals that are used in different combinations to typify sedimentary rocks. The predictive capacity of the new...

  10. Preserving Privacy in Transparency Logging

    OpenAIRE

    Pulls, Tobias

    2015-01-01

    The subject of this dissertation is the construction of privacy-enhancing technologies (PETs) for transparency logging, a technology at the intersection of privacy, transparency, and accountability. Transparency logging facilitates the transportation of data from service providers to users of services and is therefore a key enabler for ex-post transparency-enhancing tools (TETs). Ex-post transparency provides information to users about how their personal data have been processed by service pr...

  11. Well-logging responses and reservoir effects of rhyolite's diagenesises of Yingcheng Formation(Kly)in the Songliao Basin%松辽盆地营城组流纹岩成岩作用的测井响应及其储层效应

    Institute of Scientific and Technical Information of China (English)

    瞿雪姣; 王璞珺; 修立军; 唐华风; 高有峰

    2011-01-01

    Through observation of well core and thin sections and study of well-logging responses, we found that three kinds of diagenesises'well-logging responses are prominently, includes diagenetic albitization of kfeldspars, amygdules and fractures filled with quartz and matrix and/or phanerocrysts alternated by calcite, while denudation and devitrification are associated with other diagenesises in rhyolite. Diagenetic albitization of kfeldspars characterized as Na/K>l in ECS log and the stronger of the alternation the larger of the ratio,and the electrical resistivity is low, logging porosity shows a single peak in histogram. The features of amygdules and fractures filled with quartz includes high density, low logging porosity and low neutron in the cross-plots of DEN versus AC and Pige versus CN,the electrical resistivity toothly nearly to straight and mainly between 40 fl ? M and 100 fl ? M. Matrix and/orphanerocrysts alternated by calcite indicates the Ca curve smoothly and straightly and diverged the base line obviously,the conventional well-logging responses shows low electrical resistivity 、 low density,high acoustictime and high logging porosity. As a result of diagenetic albitization of kfeldspars, the reservoir quality improved overally, especially for the tight zone,the theoretical maximum increment of porosity is 6. 8%,the actual increment of porosity is 0. 15%'-0. 46%. Amygdules and fractures filled with quartz deteriorate the reservoir quality. The reservoir effect of matrix and/or phanerocrysts alternated by calcite mainly determined by the dissolution degree, the porosity theoretically reduced about 46% after amorphous silica in matrix alternated by calcite, the actual reduction of porosity is about 2. 3%.%岩心、薄片观察和测井响应关系研究发现,钾长石钠长石化、石英充填、方解石交代是流纹岩中三种测井响应特征明显的成岩作用,与其伴生的还有溶蚀和基质脱玻化作

  12. Les terrains jurassiques du sondage de Couy (Cher, France. Leur analyse séquentielle détaillée à partir de la description des carottes et des courbes diagraphiques Jurassic Formations in the Couy Borehole (Cher Department, France. Their Detailed Sequential Analysis from the Core Sample Descriptions and Well-Logging Curves

    Directory of Open Access Journals (Sweden)

    Gely J. P.

    2006-11-01

    Full Text Available Le forage de Couy-Sancerre (Programme Géologie profonde de la France avait pour objectif d'atteindre l'Anomalie magnétique du Bassin Parisien. La série sédimentaire entièrement carottée, complétée par un jeu complet de diagraphies modernes (micro-résistivité, sonique, gamma-ray, densité, neutron, PEF, pendagemétrie, est le plus souvent compréhensive, mais présente parfois des condensations. L'analyse séquentielle du forage de Couy a permis de mettre en évidence 17 séquences dans le Jurassique inférieur et une partie du Jurassique moyen. Dans le Jurassique inférieur, les 11 séquences caractérisées (la dernière passant dans le Jurassique moyen sont très semblables à celles proposées par Haq et ai. (1988 . Pour le Jurassique moyen, les 8 séquences reconnues sont assez délicates à corréler avec celles proposées par Haq et al. (1988 , aussi bien que par Rioult et al. (1991 en Normandie ou par Gonnin et al. (1993 en Poitou. Le forage de Couy, par ses données lithostratigraphiques et biostratigraphiques, ainsi que par ses enregistrements diagraphiques bien calés, constitue un sondage de référence pour la stratigraphie du Bassin Parisien. The Couy-Sancerre borehole (Deep Geology Program of France had the target of reaching the Paris Basin magnetic anomaly. It was located in the eastern part of the Biturige subblock, more precisely between the Armorican Block and the Burgondy Block, on the edge of the Loire Trough, on the site of the Mesozoic Marly Trough. It was located on a small intermediate horst (Fig. 1. The sedimentary series has been entirely cored, and this has been completed by a complete set of modern well logs (microresistivity, sonic, gamma ray, formation density, compensated neutron, photoelectric effect, dipmetering. This series is often comprehensive, but sometimes shows condensations. Petrographic and mineralogic studies (Delavenna et al. , 1989; Mélières, 1991 and the determining of numerous ammonites

  13. User Behavior Analysis from Web Log using Log Analyzer Tool

    Directory of Open Access Journals (Sweden)

    Brijesh Bakariya

    2013-11-01

    Full Text Available Now a day, internet plays a role of huge database in which many websites, information and search engines are available. But due to unstructured and semi-structured data in webpage, it has become a challenging task to extract relevant information. Its main reason is that traditional knowledge based technique are not correct to efficiently utilization the knowledge, because it consist of many discover pattern, contains a lots of noise and uncertainty. In this paper, analyzing of web usage mining has been made with the help if web log data for which web log analyzer tool, “Deep Log Analyzer” to find out abstract information from particular server and also tried to find out the user behavior and also developed an ontology which consist the relation among efficient web apart of web usage mining.

  14. HMR Log Analyzer: Analyze Web Application Logs Over Hadoop MapReduce

    Directory of Open Access Journals (Sweden)

    Sayalee Narkhede

    2013-07-01

    Full Text Available In today’s Internet world, log file analysis is becoming a necessary task for analyzing the customer’sbehavior in order to improve advertising and sales as well as for datasets like environment, medical,banking system it is important to analyze the log data to get required knowledge from it. Web mining is theprocess of discovering the knowledge from the web data. Log files are getting generated very fast at therate of 1-10 Mb/s per machine, a single data center can generate tens of terabytes of log data in a day.These datasets are huge. In order to analyze such large datasets we need parallel processing system andreliable data storage mechanism. Virtual database system is an effective solution for integrating the databut it becomes inefficient for large datasets. The Hadoop framework provides reliable data storage byHadoop Distributed File System and MapReduce programming model which is a parallel processingsystem for large datasets. Hadoop distributed file system breaks up input data and sends fractions of theoriginal data to several machines in hadoop cluster to hold blocks of data. This mechanism helps toprocess log data in parallel using all the machines in the hadoop cluster and computes result efficiently.The dominant approach provided by hadoop to “Store first query later”, loads the data to the HadoopDistributed File System and then executes queries written in Pig Latin. This approach reduces the responsetime as well as the load on to the end system. This paper proposes a log analysis system using HadoopMapReduce which will provide accurate results in minimum response time.

  15. Maintaining ecosystem function and services in logged tropical forests.

    Science.gov (United States)

    Edwards, David P; Tobias, Joseph A; Sheil, Douglas; Meijaard, Erik; Laurance, William F

    2014-09-01

    Vast expanses of tropical forests worldwide are being impacted by selective logging. We evaluate the environmental impacts of such logging and conclude that natural timber-production forests typically retain most of their biodiversity and associated ecosystem functions, as well as their carbon, climatic, and soil-hydrological ecosystem services. Unfortunately, the value of production forests is often overlooked, leaving them vulnerable to further degradation including post-logging clearing, fires, and hunting. Because logged tropical forests are extensive, functionally diverse, and provide many ecosystem services, efforts to expand their role in conservation strategies are urgently needed. Key priorities include improving harvest practices to reduce negative impacts on ecosystem functions and services, and preventing the rapid conversion and loss of logged forests.

  16. INSPIRE and SPIRES Log File Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Adams, Cole; /Wheaton Coll. /SLAC

    2012-08-31

    SPIRES, an aging high-energy physics publication data base, is in the process of being replaced by INSPIRE. In order to ease the transition from SPIRES to INSPIRE it is important to understand user behavior and the drivers for adoption. The goal of this project was to address some questions in regards to the presumed two-thirds of the users still using SPIRES. These questions are answered through analysis of the log files from both websites. A series of scripts were developed to collect and interpret the data contained in the log files. The common search patterns and usage comparisons are made between INSPIRE and SPIRES, and a method for detecting user frustration is presented. The analysis reveals a more even split than originally thought as well as the expected trend of user transition to INSPIRE.

  17. Detecting Botnets Through Log Correlation

    CERN Document Server

    Al-Hammadi, Yousof

    2010-01-01

    Botnets, which consist of thousands of compromised machines, can cause significant threats to other systems by launching Distributed Denial of Service (SSoS) attacks, keylogging, and backdoors. In response to these threats, new effective techniques are needed to detect the presence of botnets. In this paper, we have used an interception technique to monitor Windows Application Programming Interface (API) functions calls made by communication applications and store these calls with their arguments in log files. Our algorithm detects botnets based on monitoring abnormal activity by correlating the changes in log file sizes from different hosts.

  18. A forward modeling approach for interpreting impeller flow logs.

    Science.gov (United States)

    Parker, Alison H; West, L Jared; Odling, Noelle E; Bown, Richard T

    2010-01-01

    A rigorous and practical approach for interpretation of impeller flow log data to determine vertical variations in hydraulic conductivity is presented and applied to two well logs from a Chalk aquifer in England. Impeller flow logging involves measuring vertical flow speed in a pumped well and using changes in flow with depth to infer the locations and magnitudes of inflows into the well. However, the measured flow logs are typically noisy, which leads to spurious hydraulic conductivity values where simplistic interpretation approaches are applied. In this study, a new method for interpretation is presented, which first defines a series of physical models for hydraulic conductivity variation with depth and then fits the models to the data, using a regression technique. Some of the models will be rejected as they are physically unrealistic. The best model is then selected from the remaining models using a maximum likelihood approach. This balances model complexity against fit, for example, using Akaike's Information Criterion.

  19. Avoid Logs to Avoid Ticks

    Institute of Scientific and Technical Information of China (English)

    莫文佳

    2004-01-01

    扁虱是莱姆关节炎的罪魁祸首。研究人员为了弄明白何处扁虱最猖獗, 不惜以身作饵,他们发现:The ticks were all over the log surface。因此告诫人 们:Avoid sitting on logs。

  20. Decomposable log-linear models

    DEFF Research Database (Denmark)

    Eriksen, Poul Svante

    can be characterized by a structured set of conditional independencies between some variables given some other variables. We term the new model class decomposable log-linear models, which is illustrated to be a much richer class than decomposable graphical models.It covers a wide range of non...

  1. 29 CFR 1918.88 - Log operations.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Log operations. 1918.88 Section 1918.88 Labor Regulations...) SAFETY AND HEALTH REGULATIONS FOR LONGSHORING Handling Cargo § 1918.88 Log operations. (a) Working in holds. When loading logs into the holds of vessels and using dumper devices to roll logs into the...

  2. Hardwood log supply: a broader perspective

    Science.gov (United States)

    Iris Montague; Adri Andersch; Jan Wiedenbeck; Urs. Buehlmann

    2015-01-01

    At regional and state meetings we talk with others in our business about the problems we face: log exports, log quality, log markets, logger shortages, cash flow problems, the weather. These are familiar talking points and real and persistent problems. But what is the relative importance of these problems for log procurement in different regions of...

  3. Bi-log-concave Distribution Functions

    DEFF Research Database (Denmark)

    Dümbgen, Lutz; Kolesnyk, Petro; Wilke, Ralf

    2017-01-01

    Nonparametric statistics for distribution functions F or densities f=F′ under qualitative shape constraints constitutes an interesting alternative to classical parametric or entirely nonparametric approaches. We contribute to this area by considering a new shape constraint: F is said to be bi......-log-concave, if both logF and log(1−F) are concave. Many commonly considered distributions are compatible with this constraint. For instance, any c.d.f. F with log-concave density f=F′ is bi-log-concave. But in contrast to log-concavity of f, bi-log-concavity of F allows for multimodal densities. We provide various...

  4. A product autoregressive model with log-Laplace marginal distribution

    Directory of Open Access Journals (Sweden)

    Kanichukattu K. Jose

    2013-05-01

    Full Text Available The log-Laplace distribution and its properties are considered. Some important properties like multiplicative infinite divisibility, geometric multiplicative infinite divisibility and self-decomposability are discussed. A first order product autoregressive model with log-Laplace marginal distribution is developed. Simulation studies are conducted as well as sample path properties and estimation of parameters of the process are discussed. Further multivariate extensions are also considered.

  5. Accurately determining log and bark volumes of saw logs using high-resolution laser scan data

    Science.gov (United States)

    R. Edward Thomas; Neal D. Bennett

    2014-01-01

    Accurately determining the volume of logs and bark is crucial to estimating the total expected value recovery from a log. Knowing the correct size and volume of a log helps to determine which processing method, if any, should be used on a given log. However, applying volume estimation methods consistently can be difficult. Errors in log measurement and oddly shaped...

  6. 利用测井资料识别层序地层单元技术与方法进展及趋势%Progress and Developing Tendency of Technologies and Methods Used to Recognise Sequence Stratigraphic Units Based on the Well-Log Data

    Institute of Scientific and Technical Information of China (English)

    朱红涛; 黄众; 刘浩冉; Keyu Liu; 刘强虎

    2011-01-01

    测井曲线包含丰富的地质信息,测井曲线的形态、幅度可以反映出岩性和沉积旋回韵律等地层特征.在综述国内外研究成果的基础上,认为基于测井资料进行层序地层单元划分的方法可以分为定性和定量识别两种,其中,定性方法有自然电位和自然电位镜像法、声波时差与电阻率曲线重叠法、声波时差法、自然电位和视电阻率组合法以及累计地层倾角测井法等;定量识别方法有时频分析技术、INPEFA技术、多尺度小波分析技术、经验模态分解法、测井曲线分形分析和测井多尺度数据融合方法等.人工神经网络、人工智能技术和多尺度数据融合方法将是测井识别层序地层单元研究的趋势.结合INPEFA定量识别方法对西湖凹陷钻井层序地层单元定量识别进行实例分析,效果良好.%The logging curve contains abundant geological information. The shape and amplitude reflect the lithological and sedimentary cycles of strata. Based on the research results of domestic and overseas scholars, the paper proposes the subdivision of the recognition of sequence stratigraphic units based on the well-log data into qualitative and quantitative methods. The qualitative methods to recognize sequence strati-graphic units include SP, SP mirror image method, crossing method of AC and RA, AC method, method of combination of SP and RA, accumulation angle method. The quantitative methods to recognize sequence stratigraphic units include time-frequency analysis technology, INPEFA technology, wavelet analysis technology, fractal analysis method, and multiscale analysis method, et al. Artificial neural network, artificial intelligence processing and multiscale analysis method will be the research tendency of quantitative recognition of sequence stratigraphic units. As one example, the sequence stratigraphic units of Xihu Depression are recognized quantitatively using the INPEFA method with excellent

  7. Logística empresarial

    Directory of Open Access Journals (Sweden)

    Feres Sahid

    1987-04-01

    Full Text Available RESUMEN El concepto logístico, se pudo ver reflejado con exactitud desde el punto de vista etimológico e histórico a través de la revista de la E.A.N; ya que  tiene cierto carácter militar que lo hace característico a la gestión empresarial y de esto se formula un debate definitivo de este concepto.

  8. AUTOMATED TECHNIQUE FOR CREATING LITHOLOGIC LOG PLOTS

    Directory of Open Access Journals (Sweden)

    Kristijan Posavec

    2006-12-01

    Full Text Available Paper presents automated technique for creating lithologic log plots. Technique is based on three computer tools: Microsoft (MS Access program, LogPlot program, and Visual Basic (VB macros for MS Excel. MS Access ensures professional storage of lithologic data which can be in that way easier and faster entered, searched, updated, and also used for different purposes, while LogPlot provides tools for creating lithologic log plots. VB macros enable transfer of lithologic data from MS Access to LogPlot. Data stored in MS Access are exported in ASCII files which are later used by LogPlot for creation of lithologic log plots. Presented concept facilitates creation of lithologic log plots, and automated technique enables processing of a large number of data i.e. creation of lareg number lithologic log plots in a short period of time (the paper is published in Croatian.

  9. Chiral Logs in Quenched QCD

    CERN Document Server

    Dong, S J; Horváth, I; Lee, F X; Liu, K F; Mathur, N; Zhang, J B

    2003-01-01

    The quenched chiral logs are examined on a $16^3 \\times 28$ lattice with Iwasaki gauge action and overlap fermions. The pion decay constant $f_{\\pi}$ is used to set the lattice spacing, $a = 0.200(3)$ fm. With pion mass as low as $\\sim 180 {\\rm MeV}$, we see the quenched chiral logs clearly in $m_{\\pi}^2/m$ and $f_P$, the pseudoscalar decay constant. We analyze the data to determine how low the pion mass needs to be in order for the quenched one-loop chiral perturbation theory ($\\chi$PT) to apply. With the constrained curve fitting, we are able to extract the quenched chiral log parameter $\\delta$ together with the chiral cutoff $\\Lambda_{\\chi}$ and other parameters. Only for $m_{\\pi} \\leq 300 {\\rm MeV}$ do we obtain a consistent and stable fit with a constant $\\delta$ which we determine to be 0.23(2). By comparing to the $12^3 \\times 28$ lattice, we estimate the finite volume effect to be about 1.8% for the smallest pion mass. We also study the quenched non-analytic terms in the nucleon and the $\\rho$ masses...

  10. Mud-filtrate correction of sonic logs by fluid substitution

    DEFF Research Database (Denmark)

    Sørensen, Morten Kanne

    . The pressure in the borehole is kept higher than in the surrounding formation to control fluid production from the borehole. The over pressure in the borehole drives fluid from the borehole into the formation, whereby a sonic log measures velocities at a different saturation than the formation saturation......, which the seismic data probes. For a proper well-tie sonic logs therefore require correction. Gassmann (1951) fluid substitution relates elastic velocities of a porous medium at one saturation to the elastic velocities at another saturation. Fluid substation can then predict a sonic log...... at the undisturbed formation saturation from the invaded saturation. Fluid substitution is exact for a uniform, high-permeable porous medium saturated by a single fluid. Rocks does not necessarily conform to these requirements, and both the formation saturation and invaded saturation involve two fluids. Sonic log...

  11. Log-periodicity: Sources, characterization, identification, and possible applications

    Science.gov (United States)

    Huang, Yueqiang

    1999-11-01

    We investigate theoretically the log-periodic oscillations that have recently been observed in several rupture processes ranging from earthquakes to financial crashes. A possible source of log-periodic oscillations is an underlying discrete scale invariance (DSI). The first chapter of this dissertation is devoted to understanding how DSI could appear spontaneously in a physical system. We consider the example of crack arrays, and argue that the short-wavelength Mullins-Sekerka instability, together with strong screening effects, could indeed generate DSI. This is backed by extensive numerical simulations, as well as some experimental observations. In the second chapter of this dissertation, we study in more details how DSI at the geometrical level can give rise to log-periodic oscillations in a rupture process: to do so, we explore in details a simple cellular automaton model of earthquakes on a fractal lattice and show how the divergence of the correlation length, combined with the fractal geometrical structure, determines the log-periodic oscillations. Despite its simplicity, we demonstrate that our model reproduces remarkably well the statistical aspects of earthquakes, in contrast with original, erroneous conclusions of early works on the matter. The key issue here is the interplay of self-organized criticality, finite size effects, and dissipation. Besides DSI, we point out that there are other possible sources of log-periodicity arising from data analysis. We discuss in considerable details the effects of noise integration in power laws. We point out that this mechanism calls for a re-examination of the interpretation of many previously observed log-periodic oscillations. We re-visit two early observations, the Loma Prieta case and the Kobe case, and unfortunately find that the observed log-periodic oscillations are not as significant as originally claimed. Finally, this dissertation also contains an important observational part in which we analyze in details

  12. The Log Log Prior for the Frequency of Extraterrestrial Intelligences

    CERN Document Server

    Lacki, Brian C

    2016-01-01

    It is unclear how frequently life and intelligence arise on planets. I consider a Bayesian prior for the probability P(ETI) that intelligence evolves at a suitable site, with weight distributed evenly over ln(1 - ln P(ETI)). This log log prior can handle a very wide range of P(ETI) values, from 1 to 10^(-10^122), while remaining responsive to evidence about extraterrestrial societies. It is motivated by our uncertainty in the number of conditions that must be fulfilled for intelligence to arise, and it is related to considerations of information, entropy, and state space dimensionality. After setting a lower limit to P(ETI) from the number of possible genome sequences, I calculate a Bayesian confidence of 18% that aliens exist within the observable Universe. With different assumptions about the minimum P(ETI) and the number of times intelligence can appear on a planet, this value falls between 1.4% and 47%. Overall, the prior leans towards our being isolated from extraterrestrial intelligences, but indicates ...

  13. Data Mining of Network Logs

    Science.gov (United States)

    Collazo, Carlimar

    2011-01-01

    The statement of purpose is to analyze network monitoring logs to support the computer incident response team. Specifically, gain a clear understanding of the Uniform Resource Locator (URL) and its structure, and provide a way to breakdown a URL based on protocol, host name domain name, path, and other attributes. Finally, provide a method to perform data reduction by identifying the different types of advertisements shown on a webpage for incident data analysis. The procedures used for analysis and data reduction will be a computer program which would analyze the URL and identify and advertisement links from the actual content links.

  14. The Closed Form on a Kind of Log-cosine and Log-sine Integral%一类log-cosine和log-sine积分的闭形式

    Institute of Scientific and Technical Information of China (English)

    商妮娜; 秦惠增

    2012-01-01

    We consider some recursion formulas for the partial derivative of Beta function. Using these recursion formulas, we give the closed form of the log-cosine and log-sine integral.%考虑了Beta函数偏导数的递推公式的表示问题.利用Beta函数偏导数的递推公式,给出一类log-cosine和log-sine积分的闭形式.

  15. Non-Linear Logging Parameters Inversion

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    The non-linear logging parameters inversion is based on the field theory, information optimization and predication theory. It uses seismic charaoters,geological model and logging data as a restriction to inverse 2D, 3D logging parameters data volume. Using this method,

  16. 29 CFR 1917.18 - Log handling.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 7 2010-07-01 2010-07-01 false Log handling. 1917.18 Section 1917.18 Labor Regulations...) MARINE TERMINALS Marine Terminal Operations § 1917.18 Log handling. (a) The employer shall ensure that structures (bunks) used to contain logs have rounded corners and rounded structural parts to avoid...

  17. 47 CFR 73.1820 - Station log.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Station log. 73.1820 Section 73.1820... Rules Applicable to All Broadcast Stations § 73.1820 Station log. (a) Entries must be made in the station log either manually by a person designated by the licensee who is in actual charge of...

  18. 47 CFR 87.109 - Station logs.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station logs. 87.109 Section 87.109... Operating Requirements and Procedures Operating Procedures § 87.109 Station logs. (a) A station at a fixed location in the international aeronautical mobile service must maintain a log in accordance with Annex...

  19. 10 CFR 34.71 - Utilization logs.

    Science.gov (United States)

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Utilization logs. 34.71 Section 34.71 Energy NUCLEAR... RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.71 Utilization logs. (a) Each licensee shall maintain utilization logs showing for each sealed source the following information: (1) A description, including...

  20. Selective logging in the Brazilian Amazon.

    Science.gov (United States)

    G. P. Asner; D. E. Knapp; E. N. Broadbent; P. J. C. Oliveira; M Keller; J. N. Silva

    2005-01-01

    Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square...

  1. Multivariate log-skew-elliptical distributions with applications to precipitation data

    KAUST Repository

    Marchenko, Yulia V.

    2009-07-13

    We introduce a family of multivariate log-skew-elliptical distributions, extending the list of multivariate distributions with positive support. We investigate their probabilistic properties such as stochastic representations, marginal and conditional distributions, and existence of moments, as well as inferential properties. We demonstrate, for example, that as for the log-t distribution, the positive moments of the log-skew-t distribution do not exist. Our emphasis is on two special cases, the log-skew-normal and log-skew-t distributions, which we use to analyze US national (univariate) and regional (multivariate) monthly precipitation data. © 2009 John Wiley & Sons, Ltd.

  2. Lake Tahoe Nevada Division of Water Resources State Well Log Database Wells

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — These data present a ground-water inventory of existing geospatial data and other information needed to determine the extent and characteristics of the aquifers in...

  3. Latent log-linear models for handwritten digit classification.

    Science.gov (United States)

    Deselaers, Thomas; Gass, Tobias; Heigold, Georg; Ney, Hermann

    2012-06-01

    We present latent log-linear models, an extension of log-linear models incorporating latent variables, and we propose two applications thereof: log-linear mixture models and image deformation-aware log-linear models. The resulting models are fully discriminative, can be trained efficiently, and the model complexity can be controlled. Log-linear mixture models offer additional flexibility within the log-linear modeling framework. Unlike previous approaches, the image deformation-aware model directly considers image deformations and allows for a discriminative training of the deformation parameters. Both are trained using alternating optimization. For certain variants, convergence to a stationary point is guaranteed and, in practice, even variants without this guarantee converge and find models that perform well. We tune the methods on the USPS data set and evaluate on the MNIST data set, demonstrating the generalization capabilities of our proposed models. Our models, although using significantly fewer parameters, are able to obtain competitive results with models proposed in the literature.

  4. Determining Partition Coefficient (Log P), Distribution Coefficient (Log D) and Ionization Constant (pKa) in Early Drug Discovery.

    Science.gov (United States)

    Bharate, Sonali S; Kumar, Vikas; Vishwakarma, Ram A

    2016-01-01

    An early prediction of physicochemical properties is highly desirable during drug discovery to find out a viable lead candidate. Although there are several methods available to determine partition coefficient (log P), distribution coefficient (log D) and ionization constant (pKa), none of them involves simple and fixed, miniaturized protocols for diverse set of compounds. Therefore, it is necessary to establish simple, uniform and medium-throughput protocols requiring small sample quantities for the determination of these physicochemical properties. Log P and log D were determined by shake flask method, wherein, the compound was partitioned between presaturated noctanol and water phase (water/PBS pH 7.4) and the concentration of compound in each phase was determined by HPLC. The pKa determination made use of UV spectrophotometric analysis in a 96-well microtiter plate containing a series of aqueous buffers ranging from pH 1.0 to 13.0. The medium-throughput miniaturized protocols described herein, for determination of log P, log D and pKa, are straightforward to set up and require very small quantities of sample (< 5 mg for all three properties). All established protocols were validated using diverse set of compounds.

  5. Penerapan Reduced Impact Logging Menggunakan Monocable Winch (Pancang Tarik (Implementing Reduced Impact Logging with Monocable Winch

    Directory of Open Access Journals (Sweden)

    Yosep Ruslim

    2012-01-01

    Full Text Available Forest harvesting still encounters many problems especially concerning impact to the residual stand  and environmental damage. Implementing the reduced impact monocable winch and planning of good skid trails should have a positive impact on work efficiency as well as, reducing damage to the residual stand and soil during felling and skidding activities. Reduced impact logging (RIL with a monocable winch (Pancang Tarik system has been tried in several IUPHHKs and it can be concluded that RIL monocable winch system could be applied practically and reduce impact on residual stand and soil damage. Using this technology has many advantages, among others: cost efficiency, locally made, environmental friendly, and high local community participation. Application of  the monocable winch  system in reduced impact logging is an effort to reduce economical and environment  damages when compared to conventional system of ground based skidding with bulldozer system. The aim of this research is to verify the efficiency (operational cost, effectiveness (productivity and  time consumption of monocable winch system. The results  indicate that the implementation monocable winch system, has reduced the soil damage as much as 8% ha-1.  The skidding cost  with monocable system is Rp95.000 m-3. This figure is significantly cheaper if compare with ground base skidding with bulldozer system in which the skidding cost around Rp165.000 m-3.Keywords: mononocable winch, productivity,  skidding cost, reduced impact logging, local community

  6. Log-ω-hyponormal Operators%Log-ω亚正规算子

    Institute of Scientific and Technical Information of China (English)

    王斌; 张敏

    2008-01-01

    Let T be an operator on a separable Hilbert space H and T=U|T|bethe polaf decomposition.T is said to be log-ω-hyponormal if log|T|≥log|T|≥log|(T)*|In this paper we prove that the point spectrum of T is equal to its joint point spectrum if T is log-ω-hyponormal.We also prove that a log-ω-hyponormal operator is normaloid,i.e.,r(T)=‖T‖.Finally,we obtain Putnam's theorem for log-ω-hyponormal Operators.

  7. Analysis of Web Proxy Logs

    Science.gov (United States)

    Fei, Bennie; Eloff, Jan; Olivier, Martin; Venter, Hein

    Network forensics involves capturing, recording and analysing network audit trails. A crucial part of network forensics is to gather evidence at the server level, proxy level and from other sources. A web proxy relays URL requests from clients to a server. Analysing web proxy logs can give unobtrusive insights to the browsing behavior of computer users and provide an overview of the Internet usage in an organisation. More importantly, in terms of network forensics, it can aid in detecting anomalous browsing behavior. This paper demonstrates the use of a self-organising map (SOM), a powerful data mining technique, in network forensics. In particular, it focuses on how a SOM can be used to analyse data gathered at the web proxy level.

  8. CNLC Provides Well-Bore Technical Services Worldwide

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    @@ BRIEF INTRODUCTION of CNLC China National Logging Corporation (CNLC), a subsidiary of CNPC Services & Engineering Ltd.,which provides well bore technical services at international market solely on behalf of CNPC, is a specialized service company mainly engaged in: 1. Wire-line logging, mud logging, well testing,well completion, perforating and other relevant engineering services.

  9. Characterization of reservoir fractures using conventional geophysical logging

    Directory of Open Access Journals (Sweden)

    Paitoon Laongsakul

    2011-04-01

    Full Text Available In hydrocarbon exploration fractures play an important role as possible pathways for the hydrocarbon flow and bythis enhancing the overall formation’s permeability. Advanced logging methods for fracture analysis, like the boreholeacoustic televiewer and Formation Microscanner (FMS are available, but these are additional and expensive tools. However,open and with water or hydrocarbon filled fractures are also sensitive to electrical and other conventional logging methods.For this study conventional logging data (electric, seismic, etc were available plus additional fracture information from FMS.Taking into account the borehole environment the results show that the micro-spherically focused log indicates fractures byshowing low resistivity spikes opposite open fractures, and high resistivity spikes opposite sealed ones. Compressional andshear wave velocities are reduced when passing trough the fracture zone, which are assumed to be more or less perpendicularto borehole axis. The photoelectric absorption curve exhibit a very sharp peak in front of a fracture filled with bariteloaded mud cake. The density log shows low density spikes that are not seen by the neutron log, usually where fractures,large vugs, or caverns exist. Borehole breakouts can cause a similar effect on the logging response than fractures, but fracturesare often present when this occurs. The fracture index calculation by using threshold and input weight was calculatedand there was in general a good agreement with the fracture data from FMS especially in fracture zones, which mainlycontribute to the hydraulic system of the reservoir. Finally, the overall results from this study using one well are promising,however further research in the combination of different tools for fracture identification is recommended as well as the useof core for further validation.

  10. logR-logT Figure and Unknown Solar System Planets%logR-logT图与太阳系未知行星

    Institute of Scientific and Technical Information of China (English)

    潘彩娟; 王小波; 韦鸿铭

    2011-01-01

    Using logR-logT figure to research the planet-satellite system in Solar system, the moving of satellites are in accordance with the Kepler's Third Law, And there is a relationship between the mass of central celestial body and the straight line distances. The logR-logT figure of the unknown planet-satellite system, Mercury-satellite and Venus-satellite are described, we speculated the mass and the period of the unknown planet, the location and the period of the satellites of Mercury or Venus.%利用log-logT图研究太阳系的行星卫星系统,得出八大行星卫星系统都符合开普勒第三定律,推导出行星卫星系统logR-logT图线截距与中心天体质量的关系;通过描绘未知行星卫星系统、水星卫星系统和金星卫星系统的logR-logT图线,推测未知行星的质量和公转周期,以及水星和金星的未知卫星可能存在的位置与周期.

  11. Screening efficacy of a simplified logMAR chart

    Directory of Open Access Journals (Sweden)

    Naganathan Muthuramalingam

    2016-03-01

    Full Text Available Background: Snellen acuity charts are the most commonly used method for visual acuity (VA testing in screening programmes despite comparative studies verifying that the logarithm of minimum angle of resolution (logMAR acuity measurement charts are more accurate than the Snellen chart acuity measurements. LogMAR acuity measurement charts however are not well implemented in routine clinical practice because of the increased testing time and the complexity of scoring. To implement the logMAR method in a screening programme, there has to be some simplification of it.Aim: This study evaluates the efficacy of a simplified logMAR chart, designed for VA testing over the conventional Snellen chart, in a school-based vision-screening programme.Methods: We designed a simplified logMAR chart by employing the principles of the Early Treatment Diabetic Retinopathy Study (ETDRS chart in terms of logarithmic letter size progression, inter-letter spacing, and inter-line spacing. Once the simplified logMAR chart was validated by students in the Elite school vision-screening programme, we set out to test the chart in 88 primary and middle schools in the Tiruporur block of Kancheepuram district in Tamil Nadu. One school teacher in each school was trained to screen a cross-sectional population of 10 354 primary and secondary school children (girls: 5488; boys: 4866 for VA deficits using a new, simplified logMAR algorithm. An experienced paediatric optometrist was recruited to validate the screening methods and technique used by the teachers to collect the data. Results: The optometrist screened a subset of 1300 school children from the total sample. The optometrist provided the professional insights needed to validate the clinical efficacy of the simplified logMAR algorithm and verified the reliability of the data collected by the teachers. The mean age of children sampled for validation was 8.6 years (range: 9–14 years. The sensitivity and the specificity of the

  12. Monte Carlo Numerical Models for Nuclear Logging Applications

    Directory of Open Access Journals (Sweden)

    Fusheng Li

    2012-06-01

    Full Text Available Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be measured by using a gamma ray tool. To understand the response of nuclear logging tools, the neutron transport/diffusion theory and photon diffusion theory are needed. Unfortunately, for most cases there are no analytical answers if complex tool geometry is involved. For many years, Monte Carlo numerical models have been used by nuclear scientists in the well logging industry to address these challenges. The models have been widely employed in the optimization of nuclear logging tool design, and the development of interpretation methods for nuclear logs. They have also been used to predict the response of nuclear logging systems for forward simulation problems. In this case, the system parameters including geometry, materials and nuclear sources, etc., are pre-defined and the transportation and interactions of nuclear particles (such as neutrons, photons and/or electrons in the regions of interest are simulated according to detailed nuclear physics theory and their nuclear cross-section data (probability of interacting. Then the deposited energies of particles entering the detectors are recorded and tallied and the tool responses to such a scenario are generated. A general-purpose code named Monte Carlo N– Particle (MCNP has been the industry-standard for some time. In this paper, we briefly introduce the fundamental principles of Monte Carlo numerical modeling and review the physics of MCNP. Some of the latest developments of Monte Carlo Models are also reviewed. A variety of examples are presented to illustrate the uses of Monte Carlo numerical models

  13. Local regularity analysis of strata heterogeneities from sonic logs

    Directory of Open Access Journals (Sweden)

    S. Gaci

    2010-09-01

    Full Text Available Borehole logs provide geological information about the rocks crossed by the wells. Several properties of rocks can be interpreted in terms of lithology, type and quantity of the fluid filling the pores and fractures.

    Here, the logs are assumed to be nonhomogeneous Brownian motions (nhBms which are generalized fractional Brownian motions (fBms indexed by depth-dependent Hurst parameters H(z. Three techniques, the local wavelet approach (LWA, the average-local wavelet approach (ALWA, and Peltier Algorithm (PA, are suggested to estimate the Hurst functions (or the regularity profiles from the logs.

    First, two synthetic sonic logs with different parameters, shaped by the successive random additions (SRA algorithm, are used to demonstrate the potential of the proposed methods. The obtained Hurst functions are close to the theoretical Hurst functions. Besides, the transitions between the modeled layers are marked by Hurst values discontinuities. It is also shown that PA leads to the best Hurst value estimations.

    Second, we investigate the multifractional property of sonic logs data recorded at two scientific deep boreholes: the pilot hole VB and the ultra deep main hole HB, drilled for the German Continental Deep Drilling Program (KTB. All the regularity profiles independently obtained for the logs provide a clear correlation with lithology, and from each regularity profile, we derive a similar segmentation in terms of lithological units. The lithological discontinuities (strata' bounds and faults contacts are located at the local extrema of the Hurst functions. Moreover, the regularity profiles are compared with the KTB estimated porosity logs, showing a significant relation between the local extrema of the Hurst functions and the fluid-filled fractures. The Hurst function may then constitute a tool to characterize underground heterogeneities.

  14. Face logging in Copenhagen Limestone, Denmark

    DEFF Research Database (Denmark)

    Jakobsen, Lisa; Foged, Niels Nielsen; Erichsen, Lars;

    2015-01-01

    The requirement for excavation support can be assessed from face logging. Face logs can also improve our knowledge of lithological and structural conditions within bedrock and supplement information from boreholes and geophysical logs. During the construction of 8 km metro tunnel and 4 km heating...... tunnel in Copenhagen more than 2.5 km face logs were made in 467 locations at underground stations, shafts, caverns and along bored tunnels. Over 160 geotechnical boreholes, many with geophysical logging were executed prior to construction works. The bedrock consists of Paleogene "Copenhagen limestone......" and face logs show a sub-horizontally layered structure, with alternate extremely weak to extremely strong beds of variable thickness. The rhythmicity is thought to be climatically controlled. Stronger beds represent reduced sedimentation rate related to climatic deterioration while weaker beds result from...

  15. MultiLog: a tool for the control and output merging of multiple logging applications.

    Science.gov (United States)

    Woodruff, Jonathan; Alexander, Jason

    2016-12-01

    MultiLog is a logging tool that controls, gathers, and combines the output, on-the-fly, from existing research and commercial logging applications or "loggers." Loggers record a specific set of user actions on a computing device, helping researchers to better understand environments or interactions, guiding the design of new or improved interfaces and applications. MultiLog reduces researchers' required implementation effort by simplifying the set-up of multiple loggers and seamlessly combining their output. This in turn increases the availability of logging systems to non-technical experimenters for both short-term and longitudinal observation studies. MultiLog supports two operating modes: "researcher mode" where experimenters configure multiple logging systems, and "deployment mode" where the system is deployed to user-study participants' systems. Researcher mode allows researchers to install, configure log filtering and obfuscation, observe near real-time event streams, and save configuration files ready for deployment. Deployment mode simplifies data collection from multiple loggers by running in the system tray at user log-in, starting loggers, combining their output, and securely uploading the data to a web-server. It also supports real-time browsing of log data, pausing of logging, and removal of log lines. Performance evaluations show that MultiLog does not adversely affect system performance, even when simultaneously running several logging systems. Initial studies show the system runs reliably over a period of 10 weeks.

  16. Logging identification of the Longmaxi mud shale reservoir in the Jiaoshiba area, Sichuan Basin

    Directory of Open Access Journals (Sweden)

    Yan Wei

    2014-12-01

    Full Text Available Compared with conventional gas reservoirs, shale gas reservoirs are not sensitive to petrophysical properties, making it much difficult to identify this kind of reservoirs with well logging technologies. Therefore, through a comparison of the logging curves of the Lower Silurian Longmaxi marine shale in the Jiaoshiba area, Sichuan Basin, it is found that the mud shale on conventional log curves generally features high gamma ray, high uranium, low thorium, low kalium, relative high resistivity, high interval transit time, low neutron, low density and low photoelectric absorption cross section index, while on elements logging curves, it features an increase of silicon content and a decrease of aluminum and iron content. Based on the logging response characteristics of mud shale, the logging curves most sensitive to shale, gamma ray, neutron and density logging were selected and overlaid to identify mud shale effectively. On the basis of qualitative identification, the density logging value can identify the non-organic-rich mud shale from organic-rich mud shale, because the former has a density of 2.61–2.70 g/cm3, while the latter has a density of less than 2.61 g/cm3. The identification results agree well with the results of field gas content test, TOC experiment, and gas logging, so this study can provide reference for the logging interpretation.

  17. Flow rate logging seepage meter

    Science.gov (United States)

    Reay, William G. (Inventor); Walthall, Harry G. (Inventor)

    1996-01-01

    An apparatus for remotely measuring and logging the flow rate of groundwater seepage into surface water bodies. As groundwater seeps into a cavity created by a bottomless housing, it displaces water through an inlet and into a waterproof sealed upper compartment, at which point, the water is collected by a collection bag, which is contained in a bag chamber. A magnet on the collection bag approaches a proximity switch as the collection bag fills, and eventually enables the proximity switch to activate a control circuit. The control circuit then rotates a three-way valve from the collection path to a discharge path, enables a data logger to record the time, and enables a pump, which discharges the water from the collection bag, through the three-way valve and pump, and into the sea. As the collection bag empties, the magnet leaves the proximity of the proximity switch, and the control circuit turns off the pump, resets the valve to provide a collection path, and restarts the collection cycle.

  18. NADIR: Monitoring, Error Handling, and Logging with Tango

    Science.gov (United States)

    De Marco, M.; Knapic, C.; Smareglia, R.

    2014-05-01

    The ingest and transport of a large amount of astronomical data, in geographically distributed archives, imply some challenging issues, like remote control and configuration, monitoring and logging anomalous conditions, fault tolerance and error handling. Based on this considerations and on our experience in data management, we started development of a New Archiving Distributed InfrastructuRe (NADIR), using Tango (Team 2013; S. Gara 2012), a well known distributed control system (DCSs) within scientific environments, taking advantage of its key features, like reliability, scalability, logging and alarm system, consolidated pattern and template, to solve this complexity. In this paper we discuss about design choices and technical aspects around this project.

  19. Operational logs analysis at ALMA observatory based on ELK stack

    Science.gov (United States)

    Gil, Juan P.; Reveco, Johnny; Shen, Tzu-Chiang

    2016-07-01

    During operations, the ALMA observatory generates a huge amount of logs which contain not only valuable information related to specific failures but also for long term performance analysis. We implemented a big data solution based on Elasticsearch, Logstash and Kibana. They are configured as decoupled system which causes zero impact on the existent operations. It is able to keep more than six months of operation logs online. In this paper, we'll describe this infrastructure, applications built on top of it, and the problems that we faced during its implementation.

  20. Application of nuclear logging to porosity studies in Itaborai basin

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Milena F.S.; Lima, Inaya; Lopes, Ricardo Tadeu, E-mail: milena@lin.ufrj.br, E-mail: inaya@lin.ufrj.br, E-mail: ricardo@lin.ufrj.br [Coordenacao dos Programas de Pos-Graduacao de Engenharia (COPPE/UFRJ), Rio de Janeiro, RJ (Brazil). Lab. de Instrumentacao Nuclear; Ferrucio, Paula Lucia; Borghi, Leonardo, E-mail: ferrucio@acd.ufrj.br, E-mail: borghi@ufrj.br [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Inst. de Geociencias. Dept. de Geologia; Abreu, Carlos Jorge, E-mail: jo_abreu@unb.br [Universidade de Brasilia (UnB), DF (Brazil). Inst. de Geociencias

    2011-07-01

    Nuclear logging provides information on bulk density and porosity variations by measuring the intensity of the scattered radiation induced on the formation by radioactive sources. In this study, nuclear logging was employed to analyze the pore-space system of the 2-ITAB-1-RJ well placed on the Itaborai limestone basin, in the state of Rio de Janeiro. This is one of the smallest sedimentary basin in Brazil and it is formed by clastic deposits and travertine limestone rocks which are fractured. Understanding the pore-space system of carbonate rocks has become important subject for the oil industry, specially in Brazil. A Density Gamma Probe (LSD) and a Neutron Probe (NEUT) were used for data acquisition, which nuclear logging was carried out in part of the well, with continuous detection for about 50 m of deep. The detection speed was 4 m/min for the LSD and 5 m/min for the NEUT. The results obtained by nuclear logging showed that the 2-ITAB-1-RJ well consists of three different intervals with rocks ranging from low to moderate porosity present in travertine, marls and gneisses. (author)

  1. 40 CFR 91.412 - Data logging.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 91.412 Section 91.412 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic...

  2. 40 CFR 89.409 - Data logging.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 89.409 Section 89.409 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NEW AND IN-USE NONROAD COMPRESSION-IGNITION ENGINES Exhaust Emission Test Procedures § 89.409 Data logging. (a) A computer or...

  3. 40 CFR 90.412 - Data logging.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 90.412 Section 90.412 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF EMISSIONS FROM NONROAD SPARK-IGNITION ENGINES AT OR BELOW 19 KILOWATTS Gaseous Exhaust Test Procedures § 90.412 Data logging. (a) A computer...

  4. LHCb Online Log Analysis and Maintenance System

    CERN Document Server

    Garnier, J-C; Neufeld, N; Nikolaidis, F

    2011-01-01

    History has shown, many times computer logs are the only information an administrator may have for an incident, which could be caused either by a malfunction or an attack. Due to the huge amount of logs that are produced from large-scale IT infrastructures, such as LHCb Online, critical information may be overlooked or simply be drowned in a sea of other messages. This clearly demonstrates the need for an automatic system for long-term maintenance and real time analysis of the logs. We have constructed a low cost, fault tolerant centralized logging system which is able to do in-depth analysis and cross-correlation of every log. This system is capable of handling O(10000) different log sources and numerous formats, while trying to keep the overhead as low as possible. It provides log gathering and management, Offline analysis and online analysis. We call Offline analysis the procedure of analyzing old logs for critical information, while Online analysis refer to the procedure of early alerting and reacting. ...

  5. Chernoff's density is log-concave.

    Science.gov (United States)

    Balabdaoui, Fadoua; Wellner, Jon A

    2014-02-01

    We show that the density of Z = argmax{W (t) - t(2)}, sometimes known as Chernoff's density, is log-concave. We conjecture that Chernoff's density is strongly log-concave or "super-Gaussian", and provide evidence in support of the conjecture.

  6. Palm distributions for log Gaussian Cox processes

    DEFF Research Database (Denmark)

    Coeurjolly, Jean-Francois; Møller, Jesper; Waagepetersen, Rasmus

    This paper reviews useful results related to Palm distributions of spatial point processes and provides a new result regarding the characterization of Palm distributions for the class of log Gaussian Cox processes. This result is used to study functional summary statistics for a log Gaussian Cox...

  7. Aggregation of log-linear risks

    DEFF Research Database (Denmark)

    Embrechts, Paul; Hashorva, Enkeleijd; Mikosch, Thomas Valentin

    2014-01-01

    In this paper we work in the framework of a k-dimensional vector of log-linear risks. Under weak conditions on the marginal tails and the dependence structure of a vector of positive risks, we derive the asymptotic tail behaviour of the aggregated risk {and present} an application concerning log...

  8. Write-Combined Logging: An Optimized Logging for Consistency in NVRAM

    OpenAIRE

    Wenzhe Zhang; Kai Lu; Mikel Luján; Xiaoping Wang; Xu Zhou

    2015-01-01

    Nonvolatile memory (e.g., Phase Change Memory) blurs the boundary between memory and storage and it could greatly facilitate the construction of in-memory durable data structures. Data structures can be processed and stored directly in NVRAM. To maintain the consistency of persistent data, logging is a widely adopted mechanism. However, logging introduces write-twice overhead. This paper introduces an optimized write-combined logging to reduce the writes to NVRAM log. By leveraging the fast-r...

  9. Selective logging in the Brazilian Amazon.

    Science.gov (United States)

    Asner, Gregory P; Knapp, David E; Broadbent, Eben N; Oliveira, Paulo J C; Keller, Michael; Silva, Jose N

    2005-10-21

    Amazon deforestation has been measured by remote sensing for three decades. In comparison, selective logging has been mostly invisible to satellites. We developed a large-scale, high-resolution, automated remote-sensing analysis of selective logging in the top five timber-producing states of the Brazilian Amazon. Logged areas ranged from 12,075 to 19,823 square kilometers per year (+/-14%) between 1999 and 2002, equivalent to 60 to 123% of previously reported deforestation area. Up to 1200 square kilometers per year of logging were observed on conservation lands. Each year, 27 million to 50 million cubic meters of wood were extracted, and a gross flux of approximately 0.1 billion metric tons of carbon was destined for release to the atmosphere by logging.

  10. Designing and Piloting a Leadership Daily Practice Log: Using Logs to Study the Practice of Leadership

    Science.gov (United States)

    Spillane, James P.; Zuberi, Anita

    2009-01-01

    Purpose: This article aims to validate the Leadership Daily Practice (LDP) log, an instrument for conducting research on leadership in schools. Research Design: Using a combination of data sources--namely, a daily practice log, observations, and open-ended cognitive interviews--the authors evaluate the validity of the LDP log. Participants: Formal…

  11. Dynamical evolution of active detached binaries on log Jo - log M diagram and contact binary formation

    CERN Document Server

    Eker, Z; Bilir, S; Karatas, Y

    2006-01-01

    Orbital angular momentum (Jo), systemic mass (M) and orbital period (P) distributions of chromospherically active binaries (CAB) and W Ursae Majoris (W UMa) systems were investigated. The diagrams of log Jo - log P, log M - log P and log Jo-log M were formed from 119 CAB and 102 W UMa stars. The log Jo-log M diagram is found to be most meaningful in demonstrating dynamical evolution of binary star orbits. A slightly curved borderline (contact border) separating the detached and the contact systems was discovered on the log Jo - log M diagram. Since orbital size (a) and period (P) of binaries are determined by their current Jo, M and mass ratio q, the rates of orbital angular momentum loss (dlog Jo/dt) and mass loss (dlog M/dt) are primary parameters to determine the direction and the speed of the dynamical evolution. A detached system becomes a contact system if its own dynamical evolution enables it to pass the contact border on the log Jo - log M diagram. Evolution of q for a mass loosing detached system is...

  12. Inverse log polar transformation algorithm based on sub-pixel interpolation

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; LI Yan-jun; ZHANG Ke; XIONG Xian-ze

    2006-01-01

    Log polar transformation is an important algorithm of space-variant vision theory.It well depicts the retino-cortical mapping.Due to the logarithmic and the arctangent operation in the transformation,the log polar coordinate of an image is mostly a decimal fraction and the range is quite narrow.Aiming at solving these problems,this paper puts forward an inverse log polar transformation based on sub-pixel interpolation.The acquired log polar image of the new algorithm has no mosaic phenomenon,meanwhile it is a better simulation of retina-cortical mapping.

  13. An approximate 3D computational method for real-time computation of induction logging responses

    NARCIS (Netherlands)

    Bensdorp, S.; Petersen, S.A.; Van den Berg, P.M.; Fokkema, J.T.

    2014-01-01

    Over many years, induction logging systems have been used to create well formation logs. The major drawback for the utilization of these tools is the long simulation time for a single forward computation. We proposed an efficient computational method based on a contrast-type of integral-equation for

  14. Adjusting Quality index Log Values to Represent Local and Regional Commercial Sawlog Product Values

    Science.gov (United States)

    Orris D. McCauley; Joseph J. Mendel; Joseph J. Mendel

    1969-01-01

    The primary purpose of this paper is not only to report the results of a comparative analysis as to how well the Q.I. method predicts log product values when compared to commercial sawmill log output values, but also to develop a methodology which will facilitate the comparison and provide the adjustments needed by the sawmill operator.

  15. The fluid-compensated cement bond log

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, T.H.; Leslie, H.D.; Wheelis, W.B.

    1984-09-01

    An experimental and numerical wave mechanics study of cement bond logs demonstrated that wellsite computer processing can now segregate wellbore fluid effects from the sonic signal response to changing cement strength. Traditionally, cement logs have been interpreted as if water were in the wellbore, without consideration of wellbore fluid effects. These effects were assumed to be negligible. However, with the increasing number of logs being run in completion fluids such as CaCl/sub 2/, ZnBr/sub 2/, and CaBr/sub 2/, large variations in cement bond logs became apparent. A Schlumberger internal paper showing that bond log amplitude is related to the acoustic impedance of the fluid in which the tool is run led to a comprehensive study of wellbore fluid effects. Numerical and experimental models were developed simulating wellbore geometry. Measurements were conducted in 5-, 7-, and 95/8-in. casings by varying the wellbore fluid densities, viscosities, and fluid types (acoustic impedance). Parallel numerical modeling was undertaken using similar parameters. The results showed that the bond log amplitude varied dramatically with the wellbore fluid's acoustic impedance; for example, there was a 70 percent increase in the signal amplitude for 11.5-lb/ gal CaCl/sub 2/ over the signal amplitude in water. This led to the development of a Fluid-Compensated Bond log that corrects the amplitude for acoustic impedance of varying wellbore fluids, thereby making the measurements more directly related to the cement quality.

  16. Evaluation of geophysical logs, phase I, for Crossley Farms Superfund Site, Berks County, Pennsylvania

    Science.gov (United States)

    Conger, Randall W.

    1998-01-01

    Twenty-one wells were drilled at Crossley Farms Superfund Site between December 15, 1987, and May 1, 1988, to define and monitor the horizontal and vertical distribution of ground-water contamination emanating from a suspected contaminant source area (Blackhead Hill). Eight well clusters were drilled on or near the Crossley Site and three well clusters were drilled at locations hydrologically down gradient from the site. Depths of wells range from 21 to 299 feet below land surface. These wells were installed in saprolite in shallow, intermediate, and deep water-producing zones of the fractured bedrock aquifer. Borehole-geophysical and video logging were conducted between April 24, 1997, and May 8, 1997, to determine the water-producing zones, water-receiving zones, zones of vertical flow, borehole depth, and casing integrity in each well. This data and interpretation will be used to determine the location of the well intake for the existing open-hole wells, which will be retrofitted to isolate and monitor water-producing zones and prevent further cross-contamination within each open borehole, and identify wells that may need rehabilitation or replacement. Caliper and video logs were used to locate fractures, inflections on fluid-temperature and fluidresistivity logs indicated possible fluid-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video logs, and driller?s notes, all wells will be constructed so that water-level fluctuations can be monitored and discrete water samples collected from shallow, intermediate, and deep water-bearing zones in each well. Geophysical logs were run on seven bedrock and two deep bedrock wells. Gamma logs were run on 10 bedrock wells. Twenty-two wells were inspected visually with the borehole video camera for casing integrity.

  17. Computer vision technology in log volume inspection

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Log volume inspection is very important in forestry research and paper making engineering. This paper proposed a novel approach based on computer vision technology to cope with log volume inspection. The needed hardware system was analyzed and the details of the inspection algorithms were given. A fuzzy entropy based on image enhancement algorithm was presented for enhancing the image of the cross-section of log. In many practical applications the cross-section is often partially invisible, and this is the major obstacle for correct inspection. To solve this problem, a robust Hausdorff distance method was proposed to recover the whole cross-section. Experiment results showed that this method was efficient.

  18. Sample Log For International Mudlogging Projects

    Institute of Scientific and Technical Information of China (English)

    Wei Xinghua; Yang Haibo; Andrew Romolliwa

    2000-01-01

    Accurate sample logging is very essential part of mud logging at wellsite. During the logging work of the foreign cooperation mudlogging projects, the description of drillling cuttings (sample) required by the foreign companies is quite different from what we did at home.This paper is intended to give some ideas of description of sample at wellsite with the reference of the guidance of standards of several foreign companies and the working experiences of the author, also some problems that the geologists should pay attention to during the description of sample at wellsite.

  19. Recognizing Patterns In Log-Polar Coordinates

    Science.gov (United States)

    Weiman, Carl F. R.

    1992-01-01

    Log-Hough transform is basis of improved method for recognition of patterns - particularly, straight lines - in noisy images. Takes advantage of rotational and scale invariance of mapping from Cartesian to log-polar coordinates, and offers economy of representation and computation. Unification of iconic and Hough domains simplifies computations in recognition and eliminates erroneous quantization of slopes attributable to finite spacing of Cartesian coordinate grid of classical Hough transform. Equally efficient recognizing curves. Log-Hough transform more amenable to massively parallel computing architectures than traditional Cartesian Hough transform. "In-place" nature makes it possible to apply local pixel-neighborhood processing.

  20. Atypical Log D profile of rifampicin

    Directory of Open Access Journals (Sweden)

    Mariappan T

    2007-01-01

    Full Text Available The distribution coefficient (log D values of rifampicin, an essential first-line antitubercular drug, at gastrointestinal pH conditions are not reported in literature. Hence determinations were made using n-octanol and buffers ranging between pH 1-7. Also, log D values were predicted using Prolog D. Both the determinations showed opposite behaviour. The atypical experimental log D profile of rifampicin could be attributed to its surface-active properties, which also explained the reported permeability behaviour of the drug in various gastrointestinal tract segments.

  1. Factor analysis of borehole logs for evaluating formation shaliness: a hydrogeophysical application for groundwater studies

    Science.gov (United States)

    Szabó, Norbert Péter; Dobróka, Mihály; Turai, Endre; Szűcs, Péter

    2014-05-01

    The calculation of groundwater reserves in shaly sand aquifers requires a reliable estimation of effective porosity and permeability; the amount of shaliness as a related quantity can be determined from well log analysis. The conventionally used linear model, connecting the natural gamma-ray index to shale content, often gives only a rough estimate of shale volume. A non-linear model is suggested, which is derived from the factor analysis of well-logging data. An earlier study of hydrocarbon wells revealed an empirical relationship between the factor scores and shale volume, independent of the well site. Borehole logs from three groundwater wells drilled in the northeastern Great Hungarian Plain are analyzed to derive depth logs of factor variables, which are then correlated with shale volumes given from the method of Larionov. Shale volume logs derived by the statistical procedure are in close agreement with those derived from Larionov's formula, which confirms the validity of the non-linear approximation. The statistical results are in good accordance with laboratory measurements made on core samples. Whereas conventional methods normally use a single well log as input, factor analysis processes all available logs to provide groundwater exploration with reliable estimations of shale volume.

  2. Computer log evaluation in tertiary coal basins

    Energy Technology Data Exchange (ETDEWEB)

    Mares, S.; Krestan, J.

    1984-01-01

    The technology of working a lignite quarry in north Czechoslovakia includes use of AR, GK, GGKP, NNK and a cavernometer with digital processing of the material on an analog-digital transformer of the CSSR in the field and subsequent computer processing an an Eclipse C300. Hungarian equipment was used with recording scale: 1:100, quantization spacing was 0.1 m. The NNK probe was L = 50 cm, the NNK and GGKP calibrations were made on a rock block with known parameters. The task of logging is to determine the base of the productive interval, as well as the ash content (ASH) and calorific value (QD) of the coal in the shaft. The processing graph includes editing (translation of the conventional units into physical quantities) and construction of statistical distributions of parameters. The clay content K /sub cl/ is defined as the minimum quantity for double differential parameter GK and for NNK. The Cross plot of NNK (NPOR)-GGKP (DEN) determines the effective porosity EPOR, as well as the maximum points for porosity (48-53%) and density (1.28-1.75 g/cm/sup 3/) that characterize the coals. In order to determine QD and ASH, regression is used (linear, exponential, logarithmic, parabolic and hyperbolic). The clay type is determined by cross plot GK-GGKP. Examples are given of computer constructions, as well as the summary interpretation document which characterizes the initial and definite parameters in the bed mode (DEN, NPOR, GR, RESN, DS, VSH, EPOR, QD, ASH). The interpretation system is called SG.

  3. Comparison of formation and fluid-column logs in a heterogeneous basalt aquifer.

    Science.gov (United States)

    Paillet, F L; Williams, J H; Oki, D S; Knutson, K D

    2002-01-01

    Deep observation boreholes in the vicinity of active production wells in Honolulu, Hawaii, exhibit the anomalous condition that fluid-column electrical conductivity logs and apparent profiles of pore-water electrical conductivity derived from induction conductivity logs are nearly identical if a formation factor of 12.5 is assumed. This condition is documented in three boreholes where fluid-column logs clearly indicate the presence of strong borehole flow induced by withdrawal from partially penetrating water-supply wells. This result appears to contradict the basic principles of conductivity-log interpretation. Flow conditions in one of these boreholes was investigated in detail by obtaining flow profiles under two water production conditions using the electromagnetic flowmeter. The flow-log interpretation demonstrates that the fluid-column log resembles the induction log because the amount of inflow to the borehole increases systematically upward through the transition zone between deeper salt water and shallower fresh water. This condition allows the properties of the fluid column to approximate the properties of water entering the borehole as soon as the upflow stream encounters that producing zone. Because this condition occurs in all three boreholes investigated, the similarity of induction and fluid-column logs is probably not a coincidence, and may relate to aquifer response under the influence of pumping from production wells.

  4. Researching illegal logging and deforestation

    NARCIS (Netherlands)

    Boekhout van Solinge, T.

    2014-01-01

    Tropical deforestation such as in the Amazon can be studied well from a green criminological perspective. Ethnographic research methods form a useful way to get insight into the dynamics and complexity of tropical deforestation, which often is illegal. This article gives an account of various ethnog

  5. Efficient Preprocessing technique using Web log mining

    Science.gov (United States)

    Raiyani, Sheetal A.; jain, Shailendra

    2012-11-01

    Web Usage Mining can be described as the discovery and Analysis of user access pattern through mining of log files and associated data from a particular websites. No. of visitors interact daily with web sites around the world. enormous amount of data are being generated and these information could be very prize to the company in the field of accepting Customerís behaviors. In this paper a complete preprocessing style having data cleaning, user and session Identification activities to improve the quality of data. Efficient preprocessing technique one of the User Identification which is key issue in preprocessing technique phase is to identify the Unique web users. Traditional User Identification is based on the site structure, being supported by using some heuristic rules, for use of this reduced the efficiency of user identification solve this difficulty we introduced proposed Technique DUI (Distinct User Identification) based on IP address ,Agent and Session time ,Referred pages on desired session time. Which can be used in counter terrorism, fraud detection and detection of unusual access of secure data, as well as through detection of regular access behavior of users improve the overall designing and performance of upcoming access of preprocessing results.

  6. Mining workflow processes from distributed workflow enactment event logs

    Directory of Open Access Journals (Sweden)

    Kwanghoon Pio Kim

    2012-12-01

    Full Text Available Workflow management systems help to execute, monitor and manage work process flow and execution. These systems, as they are executing, keep a record of who does what and when (e.g. log of events. The activity of using computer software to examine these records, and deriving various structural data results is called workflow mining. The workflow mining activity, in general, needs to encompass behavioral (process/control-flow, social, informational (data-flow, and organizational perspectives; as well as other perspectives, because workflow systems are "people systems" that must be designed, deployed, and understood within their social and organizational contexts. This paper particularly focuses on mining the behavioral aspect of workflows from XML-based workflow enactment event logs, which are vertically (semantic-driven distribution or horizontally (syntactic-driven distribution distributed over the networked workflow enactment components. That is, this paper proposes distributed workflow mining approaches that are able to rediscover ICN-based structured workflow process models through incrementally amalgamating a series of vertically or horizontally fragmented temporal workcases. And each of the approaches consists of a temporal fragment discovery algorithm, which is able to discover a set of temporal fragment models from the fragmented workflow enactment event logs, and a workflow process mining algorithm which rediscovers a structured workflow process model from the discovered temporal fragment models. Where, the temporal fragment model represents the concrete model of the XML-based distributed workflow fragment events log.

  7. A small-diameter NMR logging tool for groundwater investigations.

    Science.gov (United States)

    Walsh, David; Turner, Peter; Grunewald, Elliot; Zhang, Hong; Butler, James J; Reboulet, Ed; Knobbe, Steve; Christy, Tom; Lane, John W; Johnson, Carole D; Munday, Tim; Fitzpatrick, Andrew

    2013-01-01

    A small-diameter nuclear magnetic resonance (NMR) logging tool has been developed and field tested at various sites in the United States and Australia. A novel design approach has produced relatively inexpensive, small-diameter probes that can be run in open or PVC-cased boreholes as small as 2 inches in diameter. The complete system, including surface electronics and various downhole probes, has been successfully tested in small-diameter monitoring wells in a range of hydrogeological settings. A variant of the probe that can be deployed by a direct-push machine has also been developed and tested in the field. The new NMR logging tool provides reliable, direct, and high-resolution information that is of importance for groundwater studies. Specifically, the technology provides direct measurement of total water content (total porosity in the saturated zone or moisture content in the unsaturated zone), and estimates of relative pore-size distribution (bound vs. mobile water content) and hydraulic conductivity. The NMR measurements show good agreement with ancillary data from lithologic logs, geophysical logs, and hydrogeologic measurements, and provide valuable information for groundwater investigations.

  8. Logging-while-coring method and apparatus

    Science.gov (United States)

    Goldberg, David S.; Myers, Gregory J.

    2007-11-13

    A method and apparatus for downhole coring while receiving logging-while-drilling tool data. The apparatus includes core collar and a retrievable core barrel. The retrievable core barrel receives core from a borehole which is sent to the surface for analysis via wireline and latching tool The core collar includes logging-while-drilling tools for the simultaneous measurement of formation properties during the core excavation process. Examples of logging-while-drilling tools include nuclear sensors, resistivity sensors, gamma ray sensors, and bit resistivity sensors. The disclosed method allows for precise core-log depth calibration and core orientation within a single borehole, and without at pipe trip, providing both time saving and unique scientific advantages.

  9. Supply of Rubber Wood Log in Malaysia

    Directory of Open Access Journals (Sweden)

    A. W. Noraida

    2014-06-01

    Full Text Available Issue on shortage of raw material for wood processing solved by discovery of rubber wood log as one of the substitutes the natural log. This paper examines the supply of rubber wood log in Malaysia. We employ ARDL Bound Approach Test and time series data from 1980 to 2010 which represented the whole Malaysia are used to achieve the established objectives. The result shown, in the long run harvested area and wages have 1% and 10% significant level respectively. While in the short run, there was only harvested area having an impact with 1% significant level. This result indicates that, the harvested area become the most impact towards supply of rubber wood log either in short run or in the long run. While wages as input cost gave less impact in another word it become unburden to the producers.

  10. LATTE - Log and Time Tracking for Elections

    Data.gov (United States)

    Office of Personnel Management — LATTE - Log and Time Tracking for Elections is a time tracking and voucher preparation system used to schedule employees to cover elections, to document their time...

  11. Cloud Based Log file analysis with Interactive Spark as a Service

    Directory of Open Access Journals (Sweden)

    Nurudeen Sherif

    2016-07-01

    Full Text Available The Software applications are usually programmed to generate some auxiliary text files referred to as log files. Such files are used throughout various stages of the software development, primarily for debugging and identification of errors. Use of log files makes debugging easier during testing. It permits following the logic of the program, at high level, while not having to run it in debug mode. Nowadays, log files are usually used at commercial software installations for the aim of permanent software observation and finetuning. Log files became a typical part of software application and are essential in operating systems, networks and distributed systems. Log files are usually the only way to determine and find errors in a software application, because probe effect has no effect on log file analysis. Log files are usually massive and may have an intricate structure. Though the method of generating log files is sort of easy and simple, log file analysis may well be an incredible task that needs immense computing resources and complex procedures.

  12. Evaluation of coal structure and permeability with the aid of geophysical logging technology

    Energy Technology Data Exchange (ETDEWEB)

    Xuehai Fu; Yong Qin; Geoff G.X. Wang; Victor Rudolph [China University of Mining and Technology, Xuzhou (China)

    2009-11-15

    Coal structures and the associated permeability were studied by a combined investigation of geophysical logging data and well tests from coal reservoirs of Huainan and Huaibei coalfields in China. A large amount of the site observations on coal sections of mining faces and the macroscopic investigations on textures of drilling coal cores were carried out, providing experimental information for classification of coal structures. Geophysical log was implemented in 600 boreholes for exploration of coal and coalbed methane (CBM) resources, including 10 CBM wells which were used for permeability tests. The permeability tests were conducted by using injection/fall-off method. The results, together with the log data obtained from geophysical log technologies, have been analysed by using geological statistics, permitting correlation of the permeability of coal seams to the log responses. The correlation developed in this study provides better evaluation of coal reservoir permeability, resulting in an improved CBM exploration in the given coalfields. 17 refs., 6 figs., 4 tabs.

  13. LOG PERIODIC DIPOLE ARRAY WITH PARASITIC ELEMENTS

    Science.gov (United States)

    The design and measured characteristics of dipole and monopole versions of a log periodic array with parasitic elements are discussed. In a dipole...array with parasitic elements, these elements are used in place of every alternate dipole, thereby eliminating the need of a twisted feed arrangement...for the elements to obtain log periodic performance of the anntenna. This design with parasitic elements lends itself to a monopole version of the

  14. Conversation Threads Hidden within Email Server Logs

    Science.gov (United States)

    Palus, Sebastian; Kazienko, Przemysław

    Email server logs contain records of all email Exchange through this server. Often we would like to analyze those emails not separately but in conversation thread, especially when we need to analyze social network extracted from those email logs. Unfortunately each mail is in different record and those record are not tided to each other in any obvious way. In this paper method for discussion threads extraction was proposed together with experiments on two different data sets - Enron and WrUT..

  15. 32 CFR 700.845 - Maintenance of logs.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Maintenance of logs. 700.845 Section 700.845... Commanding Officers Afloat § 700.845 Maintenance of logs. (a) A deck log and an engineering log shall be... Naval Operations. (b) A compass record shall be maintained as an adjunct to the deck log. An...

  16. 29 CFR 42.7 - Complaint/directed action logs.

    Science.gov (United States)

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Complaint/directed action logs. 42.7 Section 42.7 Labor Office of the Secretary of Labor COORDINATED ENFORCEMENT § 42.7 Complaint/directed action logs. (a) To... operation of a system of coordinated Complaint/Directed Action Logs (logs). The logs shall be maintained...

  17. Geophysical logging for groundwater investigations in Southern Thailand

    Directory of Open Access Journals (Sweden)

    Phongpiyah Klinmanee

    2012-09-01

    Full Text Available In Thailand the Department of Groundwater Resources is drilling to find vital aquifers. Sometimes groundwater formations cannot be identified clearly during drilling; therefore, geophysical logging was applied after drilling and before casing.The tool used here is measuring nine parameters in one run, natural gamma ray, spontaneous potential, single point resistance, normal resistivity (AM 8’’, 16’’, 32’’, and 64’’, mud temperature and resistivity. Cutting was used to support the geophysical interpretations. In many cases the groundwater bearing zones could be clearly identified. The combination of andthe possibility choosing from nine parameters measured provided the necessary data base to identify groundwater bearingzones in different environments. It has been demonstrated that in different wells different tools are favorable than others.Based on the conclusions of this study geophysical logging in groundwater exploration is recommended as a normalstandard technique that should be applied in every new well drilled.

  18. Evaluation of geophysical logs, Phase I, at Willow Grove Naval Air Station, Montgomery County, Pennsylvania

    Science.gov (United States)

    Conger, R.W.

    1997-01-01

    Between April and June 1997, the U.S. Navy contracted Brown and Root Environmental, Inc., to drill 20 monitor wells at the Willow Grove Naval Air Station in Horsham Township, Montgomery County, Pa. The wells were installed to monitor water levels and allow collection of water samples from shallow, intermediate, and deep water-bearing zones. Analysis of the samples will determine the horizontal and vertical distribution of any contaminated ground water migrating from known contaminant sources. Eight wells were drilled near the Fire Training Area (Site 5), five wells near the 9th Street Landfill (Site 3), four wells at the Antenna Field Landfill (Site 2), and three wells near Privet Road Compound (Site 1). Depths range from 73 to 167 feet below land surface. The U.S. Geological Survey conducted borehole-geophysical and borehole-video logging to identify water-bearing zones so that appropriate intervals could be screened in each monitor well. Geophysical logs were run on the 20 monitor wells and 1 existing well. Video logs were run on 16 wells. Caliper and video logs were used to locate fractures, inflections on fluid-temperature and fluid-resistivity logs were used to locate possible water-bearing fractures, and flowmeter measurements verified these locations. Single-point-resistance and natural-gamma logs provided information on stratigraphy. After interpretation of geophysical logs, video logs, and driller's notes, all wells were screened such that water-level fluctuations could be monitored and discrete water samples collected from one or more shallow and intermediate water-bearing zones in each borehole.

  19. Application of fullbore formation microimager logging in the evaluation of anisotropic resistivity in a thin interbed reservoir

    Science.gov (United States)

    Wang, Fei; Bian, Hui-yuan; Gao, Xu-hua; Pan, Bao-zhi

    2016-08-01

    Oil and gas reserves in sand-shale thin interbeds are extensive, but it is a challenge to achieve satisfactory precision in the identification of these interbeds using traditional logging data. Phasor induction and three-component induction logging are appropriate tools for the identification of sand-shale interbeds. Unfortunately, phasor induction data are expensive and three-component induction logging is rarely used in major domestic oil fields. As a result, evaluation of sand-shale thin interbeds heavily depends on a traditional logging suite, general image logging, array lateral logging and array induction logging, and so on. In this paper, we investigate the sand-shale thin interbed region in the northern part of the Sulige field. We propose a comprehensive method of anisotropic evaluation which is based on the combination of wellbore microresistivity image logging (fullbore formation microimage (FMI)) and high-resolution array induction logging (HRLA), where HRLA can be used instead of a traditional logging suite or high-resolution array lateral logging. The proposed method works well in the evaluation of thin interbeds in the northern part of the Sulige field. In this paper, the combination of FMI and deep resistivity of HRLA is used. It should be noted that it is possible to use deep resistivity of conventional laterolog or array induction log instead of HRLA.

  20. Filtered Log-periodogram Regression of long memory processes

    OpenAIRE

    Feng, Yuanhua; BERAN, Jan

    2008-01-01

    Filtered log-periodogram regression estimation of the fractional differencing parameter d is considered. Asymptotic properties are derived and the effect of filtering on ˆ d is investigated. It is shown that the estimator by Geweke and Porter-Hudak (1983) can be improved significantly using a simple family of filters. The essential improvement is based on a binary decision that is asymptotically correct with probability one. The idea is closely related to the well known technique of pre-white...

  1. UiLog:Improving Log-Based Fault Diagnosis by Log Analysis

    Institute of Scientific and Technical Information of China (English)

    De-Qing Zou; Hao Qin; Hai Jin

    2016-01-01

    In modern computer systems, system event logs have always been the primary source for checking system status. As computer systems become more and more complex, the interaction between software and hardware increases frequently. The components will generate enormous log information, including running reports and fault information. The sheer quantity of data is a great challenge for analysis relying on the manual method. In this paper, we implement a management and analysis system of log information, which can assist system administrators to understand the real-time status of the entire system, classify logs into different fault types, and determine the root cause of the faults. In addition, we improve the existing fault correlation analysis method based on the results of system log classification. We apply the system in a cloud computing environment for evaluation. The results show that our system can classify fault logs automatically and effectively. With the proposed system, administrators can easily detect the root cause of faults.

  2. LOG2MARKUP: State module to transform a Stata text log into a markup document

    DEFF Research Database (Denmark)

    2016-01-01

    log2markup extract parts of the text version from the Stata log command and transform the logfile into a markup based document with the same name, but with extension markup (or otherwise specified in option extension) instead of log. The author usually uses markdown for writing documents. However...... other users may decide on all sorts of markup languages, eg HTML or LaTex. The key is that markup of Stata code and Stata output can be set by the options....

  3. La logística integral como ventaja competitiva y sistema logístico

    Directory of Open Access Journals (Sweden)

    Mario Anselmo Martínez gallardo

    2013-07-01

    Full Text Available Esta investigación analiza la logística integral como una ventaja competitiva y el sistema logístico. Es opinión de los autores que la logística integral es esencial para el intercambio de mercancías, toda vez que reduce costos y hace más ágil la actividad comercial. La utilización de esta logística representa una ventaja competitiva con respecto de otras empresas por la optimización del capital y ahorro de tiempo.

  4. Researching Illegal Logging and Deforestation

    Directory of Open Access Journals (Sweden)

    Tim Boekhout van Solinge

    2014-08-01

    Full Text Available Tropical deforestation such as in the Amazon can be studied well from a green criminological perspective. Ethnographic research methods form a useful way to get insight into the dynamics and complexity of tropical deforestation, which often is illegal. This article gives an account of various ethnographic visits to the rainforests of the Amazon in the period 2003-2014. Ethnographic methods provide insight into the overlap between the legal and illegal, the functioning (or not of state institutions, the power of (corporate lobbies, and why tropical deforestation correlates with crimes such as corruption and violence. The use of ethnographic methods in forest areas where trustworthy state actors and institutions are not very present can also present danger and raise ethical issues (such as when the researcher, for reasons of safety, does not present as a criminological researcher. However, a large advantage of ethnographic visits to tropical rainforests is that they allow the gathering of local views and voices, which rarely reach the international level. These local views lead to interesting contradictions at the international level where corporate views and lobbies dominate.

  5. Event Normalization Through Dynamic Log Format Detection

    Institute of Scientific and Technical Information of China (English)

    Christoph Meinel

    2014-01-01

    The analytical and monitoring capabilities of central event re-positories, such as log servers and intrusion detection sys-tems, are limited by the amount of structured information ex-tracted from the events they receive. Diverse networks and ap-plications log their events in many different formats, and this makes it difficult to identify the type of logs being received by the central repository. The way events are logged by IT systems is problematic for developers of host-based intrusion-detection systems (specifically, host-based systems), develop-ers of security-information systems, and developers of event-management systems. These problems preclude the develop-ment of more accurate, intrusive security solutions that obtain results from data included in the logs being processed. We propose a new method for dynamically normalizing events into a unified super-event that is loosely based on the Common Event Expression standard developed by Mitre Corporation. We explain how our solution can normalize seemingly unrelat-ed events into a single, unified format.

  6. Thermal Properties of Bazhen fm. Sediments from Thermal Core Logging

    Science.gov (United States)

    Spasennykh, Mikhail; Popov, Evgeny; Popov, Yury; Chekhonin, Evgeny; Romushkevich, Raisa; Zagranovskaya, Dzhuliya; Belenkaya, Irina; Zhukov, Vladislav; Karpov, Igor; Saveliev, Egor; Gabova, Anastasia

    2016-04-01

    The Bazhen formation (B. fm.) is the hugest self-contained source-and-reservoir continuous petroleum system covering by more than 1 mln. km2 (West Siberia, Russia). High lithological differentiation in Bazhen deposits dominated by silicic shales and carbonates accompanied by extremely high total organic carbon values (of up to 35%), pyrite content and brittle mineralogical composition deteriorate standard thermal properties assessment for low permeable rocks. Reliable information of unconventional system thermal characteristics is the necessary part of works such as modelling of different processes in reservoir under thermal EOR for accessing their efficiency, developing and optimizing design of the oil recovery methods, interpretation of the well temperature logging data and for the basin petroleum modelling. A unique set of data including thermal conductivity, thermal diffusivity, volumetric heat capacity, thermal anisotropy for the B.fm. rocks was obtained from thermal core logging (high resolution continuous thermal profiling) on more than 4680 core samples (2000 of B.fm. samples are among) along seven wells for four oil fields. Some systematic peculiarities of the relation between thermal properties of the B.fm. rocks and their mineralogical composition, structural and texture properties were obtained. The high-resolution data are processed jointly with the standard petrophysical logging that allowed us to provide better separation of the formation. The research work was done with financial support of the Russian Ministry of Education and Science (unique identification number RFMEFI58114X0008).

  7. Hanford wells

    Energy Technology Data Exchange (ETDEWEB)

    McGhan, V.L.; Damschen, D.W.

    1977-06-01

    The Hanford Site contains about 2200 wells constructed from pre-Hanford Works days to the present. As of June 1977, about 1900 wells still exist, and about 850 of these existing wells were drilled to the ground-water table. About 700 of these wells (including about 24 farm wells) still contain water. The others have become dry through infiltration of sediments or a general lowering of the water table in their vicinity. This report, providing the most complete documentation of wells in and adjacent to the Hanford Site, supersedes all previous compilations of Hanford wells.

  8. Numerical Modeling of Electroacoustic Logging Including Joule Heating

    Science.gov (United States)

    Plyushchenkov, Boris D.; Nikitin, Anatoly A.; Turchaninov, Victor I.

    It is well known that electromagnetic field excites acoustic wave in a porous elastic medium saturated with fluid electrolyte due to electrokinetic conversion effect. Pride's equations describing this process are written in isothermal approximation. Update of these equations, which allows to take influence of Joule heating on acoustic waves propagation into account, is proposed here. This update includes terms describing the initiation of additional acoustic waves excited by thermoelastic stresses and the heat conduction equation with right side defined by Joule heating. Results of numerical modeling of several problems of propagation of acoustic waves excited by an electric field source with and without consideration of Joule heating effect in their statements are presented. From these results, it follows that influence of Joule heating should be taken into account at the numerical simulation of electroacoustic logging and at the interpretation of its log data.

  9. Web Log Clustering Approaches – A Survey

    Directory of Open Access Journals (Sweden)

    G. Sudhamathy,

    2011-07-01

    Full Text Available As more organization rely on the Internet and the World Wide Web to conduct business, the proposed strategies and techniques for market analysis need to be revisited in this context. We therefore present a survey of the most recent work in the field of Web usage mining, focusing on three different approaches towards web logs clustering. Clustering analysis is a widely used data mining algorithm which is a process of partitioning a set of data objects into a number of object clusters, where each data object shares the high similarity with the other objects within the same cluster but is quite dissimilar to objects in other clusters. In this work we discuss three different approaches on web logs clustering, analyze their benefits and drawbacks. We finally conclude on the most efficient algorithm based on the results of experiments conducted with various web log files.

  10. The Life Between Big Data Log Events

    Directory of Open Access Journals (Sweden)

    George Veletsianos

    2016-06-01

    Full Text Available Big data from massive open online courses (MOOCs have enabled researchers to examine learning processes at almost infinite levels of granularity. Yet, such data sets do not track every important element in the learning process. Many strategies that MOOC learners use to overcome learning challenges are not captured in clickstream and log data. In this study, we interviewed 92 MOOC learners to better understand their worlds, investigate possible mechanisms of student attrition, and extend conversations about the use of big data in education. Findings reveal three important domains of the experience of MOOC students that are absent from MOOC tracking logs: the practices at learners’ workstations, learners’ activities online but off-platform, and the wider social context of their lives beyond the MOOC. These findings enrich our understanding of learner agency in MOOCs, clarify the spaces in-between recorded tracking log events, and challenge the view that MOOC learners are disembodied autodidacts.

  11. RESERVOIR CHARACTERIZATION USING SEISMIC AND WELL ...

    African Journals Online (AJOL)

    Osondu

    2012-06-19

    Jun 19, 2012 ... Key words: Reservoir sand, Well log, Water saturation, Linear and Steiber. Introduction. Reservoir ... During analysis, seismic data can quantitatively predict ..... Wireline and Testing, Houston Texas, pp. 21 –. 89. Wan Qin ...

  12. ANALYSIS OF USING EFFICIENT LOGGING TOOLS AT PT. PURWA PERMAI IN CENTRAL KALIMANTAN

    Directory of Open Access Journals (Sweden)

    Sona Suhartana

    2008-06-01

    Full Text Available A high log demand that often exceeds its supply capability should be overcome by using appropriate logging  tools. Numerous  kinds and types of logging  tools require  a well planning in their utilization. Number of tools which are greater or fewer than what is actually needed can be disadvantageous  for a company. In relevant to these aspects, a study was carried out at a timber estate in Central Kalimantan  in 2007. The aim of the study was to find out an efficient number  of tools used for logging  in a timber  estate. The analysis was based on the target and realization of the company’s log production. The result revealed that: (1 Optimum number of logging tools depended on production target,  i.e. 41 units  of chainsaws  for felling,  42 units  of farm tractors  for skidding,  9 units of loaders for loading and unloading, and 36 units of trucks for transportation; (2 Number  of logging tools as obtained from all activities  in the field was fewer than that from  the analysis based on production target and realization. This condition  indicated that number of logging tools used in the company was not yet efficient.

  13. Well Spacing for Horizontal Wells

    Directory of Open Access Journals (Sweden)

    C.D.S. Keuengoua

    2011-06-01

    Full Text Available In the developing phase of a hydrocarbon reservoir and planning for drilling the production wells, it is necessary to drill the wells in an appropriate spacing to achieve maximum economic revenues during the reservoir life span. Well spacing which is the real location and interrelationship between producing oil or gas wells in an oil field is an important parameter. It is determined for the maximum ultimate production of a given reservoir and should be taken in consideration during well planning to avoid drilling of unnecessary wells. This study presents the concept of drainage area on horizontal well and horizontal productivity indices with different equations and their applications. A user friendly Excel Spreadsheet program was developed to calculate the productivity values of horizontal wells using three major available productivity equations. Also, the developed spreadsheet program was used to evaluate the effect of well spacing on the productivities of horizontal wells using productivity index approach and drainage area concept. It also helps to review the comparison between vertical and horizontal wells spacing based on drainage area concept. This program was validated, and then was used to study the effect of horizontal well length on the ratio of horizontal well productivity to vertical well productivity. The results show that higher ratio of horizontal well productivity to vertical well productivity values are obtained with increase length of the horizontal well. It is a very useful tool for making decision about the application of well spacing for horizontal wells.

  14. Financial feasibility of a log sort yard handling small-diameter logs: A preliminary study

    Science.gov (United States)

    Han-Sup Han; E. M. (Ted) Bilek; John (Rusty) Dramm; Dan Loeffler; Dave Calkin

    2011-01-01

    The value and use of the trees removed in fuel reduction thinning and restoration treatments could be enhanced if the wood were effectively evaluated and sorted for quality and highest value before delivery to the next manufacturing destination. This article summarizes a preliminary financial feasibility analysis of a log sort yard that would serve as a log market to...

  15. Arabidopsis lonely guy (LOG) multiple mutants reveal a central role of the LOG-dependent pathway in cytokinin activation.

    Science.gov (United States)

    Tokunaga, Hiroki; Kojima, Mikiko; Kuroha, Takeshi; Ishida, Takashi; Sugimoto, Keiko; Kiba, Takatoshi; Sakakibara, Hitoshi

    2012-01-01

    Cytokinins are phytohormones that play key roles in the maintenance of stem cell activity in plants. Although alternative single-step and two-step activation pathways for cytokinin have been proposed, the significance of the single-step pathway which is catalyzed by LONELY GUY (LOG), is not fully understood. We analyzed the metabolic flow of cytokinin activation in Arabidopsis log multiple mutants using stable isotope-labeled tracers and characterized the mutants' morphological and developmental phenotypes. In tracer experiments, cytokinin activation was inhibited most pronouncedly by log7, while the other log mutations had cumulative effects. Although sextuple or lower-order mutants did not show drastic phenotypes in vegetative growth, the log1log2log3log4log5log7log8 septuple T-DNA insertion mutant in which the LOG-dependent pathway is impaired, displayed severe retardation of shoot and root growth with defects in the maintenance of the apical meristems. Detailed observation of the mutants showed that LOG7 was required for the maintenance of shoot apical meristem size. LOG7 was also suggested to play a role for normal primary root growth together with LOG3 and LOG4. These results suggest a dominant role of the single-step activation pathway mediated by LOGs for cytokinin production, and overlapping but differentiated functions of the members of the LOG gene family in growth and development.

  16. Perfil logístico de Colombia

    OpenAIRE

    Cardozo Maglioni, María Victoria; Lozano Suarez, María Goretty

    2012-01-01

    El presente documento ofrece un estudio del perfil logístico de Colombia con la finalidad de dar a conocer el estado de arte de las ciudades, puertos e infraestructura principal para facilitar la toma de decisiones de los empresarios. Para el desarrollo de este trabajo se determinaron a partir de un análisis competitivo del país; las principales ciudades y puertos; logrando establecer un inventario de maquinaria y equipo e infraestructura logística; enmarcados en retos ya establecidos en las ...

  17. Kaizen aplicado à logística

    OpenAIRE

    Santos, Ana Catarina Almeida

    2011-01-01

    O presente trabalho propõe alcançar um aumento de produtividade e consequente redução de custos e desperdícios ajudando o departamento logístico da Empresa Revigrés – Industria de Revestimentos de Grés, Lda, a tornar-se mais eficiente, através da aplicação da filosofia kaizen que propõe melhorias no desempenho por implementação de pequenas ações. O objetivo deste projeto é a melhoria do departamento logístico globalmente, para isso houve o recurso a pesquisas e levantamento ...

  18. Solving SDD linear systems in time $\\tilde{O}(m\\log{n}\\log(1/\\epsilon))$

    CERN Document Server

    Koutis, Ioannis; Peng, Richard

    2011-01-01

    We present an algorithm that on input of an $n\\times n$ symmetric diagonally dominant matrix $A$ with $m$ non-zero entries constructs in time ${\\tilde O}(m\\log n)$ in the RAM model a solver which on input of a vector $b$ computes a vector ${x}$ satisfying $||{x}-A^{+}b||_A<\\epsilon ||A^{+}b||_A $ in time ${\\tilde O}(m\\log n \\log (1/\\epsilon))$ The $\\tilde{O}$ notation hides a $(\\log\\log n)^2$ factor. The new algorithm exploits previously unknown structural properties of the output of the incremental sparsification algorithm given in \\cite{KoutisMP10}. It is also based on an accelerated construction of low-stretch spanning trees in the RAM model via substituting Fibonacci heaps with RAM-based priority queues.

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

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

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

  20. Neutron generator for the array borehole logging

    Institute of Scientific and Technical Information of China (English)

    LuHong-Bo; ZhongZhen-Qian; 等

    1998-01-01

    The performance mechanism of the array neutron generator to be used to porosity logging is presented.The neutron generator utilizes a drive-in target ceramic neutron tube,which cursts nerutron with fast-slow period selectively pressure.Regulation of the neutron tube is accomplished by pulse width modulation.The high voltage power supply is poerated at optimum frequency.

  1. Precision Prediction of the Log Power Spectrum

    CERN Document Server

    Repp, Andrew

    2016-01-01

    At translinear scales, the log power spectrum captures significantly more cosmological information than the standard power spectrum. At high wavenumbers $k$, the cosmological information in the standard power spectrum $P(k)$ fails to increase in proportion to $k$ due to correlations between large- and small-scale modes. As a result, $P(k)$ suffers from an information plateau on these translinear scales, so that analysis with the standard power spectrum cannot access the information contained in these small-scale modes. The log power spectrum $P_A(k)$, on the other hand, captures the majority of this otherwise lost information. Until now there has been no means of predicting the amplitude of the log power spectrum apart from cataloging the results of simulations. We here present a cosmology-independent prescription for the log power spectrum, and we find this prescription to display accuracy comparable to that of Smith et al. (2003), over a range of redshifts and smoothing scales, and for wavenumbers up to $1....

  2. The fluid-compensated cement bond log

    Energy Technology Data Exchange (ETDEWEB)

    Nayfeh, T.H.; Wheelis, W.B. Jr.; Leslie, H.D.

    1986-08-01

    Simulations of cement bond logging (CBL) have shown that wellbore fluid effects can be segregated from sonic-signal response to changing cement strengths. Traditionally, the effects have been considered negligible and the CBL's have been interpreted as if water were in the wellbore. However, large variations in CBL's have become apparent with the increasing number of logs run in completion fluids, such as CaCl/sub 2/, ZnBr/sub 2/, and CaBr/sub 2/. To study wellbore fluid effects, physical and numerical models were developed that simulated the wellbore geometry. Measurements were conducted in 5-, 7-, and 9 5/8-in. casings for a range of wellbore fluid types and for both densities and viscosities. Parallel numerical modeling used similar parameters. Results show that bond-log amplitudes varied dramatically with the wellbore fluid acoustic impedance-i.e., there was a 70% increase in signal amplitudes for 11.5 lbm/gal (1370-kg/m/sup 3/) CaCl/sub 2/ over the signal amplitude in water. This led to the development of a fluid-compensated bond log that corrects the amplitude for acoustic impedance of various wellbore fluids, thereby making the measurements more directly related to the cement quality.

  3. Apache Flume distributed log collection for Hadoop

    CERN Document Server

    D'Souza, Subas

    2013-01-01

    A starter guide that covers Apache Flume in detail.Apache Flume: Distributed Log Collection for Hadoop is intended for people who are responsible for moving datasets into Hadoop in a timely and reliable manner like software engineers, database administrators, and data warehouse administrators

  4. Smartphone log data in a qualitative perspective

    DEFF Research Database (Denmark)

    Ørmen, Jacob; Thorhauge, Anne Mette

    2015-01-01

    Log data from smartphones have primarily been used in large-scale research designs to draw statistical inferences from hundreds or even thousands of participants. In this article, we argue that more qualitatively oriented designs can also benefit greatly from integrating these rich data sources...

  5. Discovering the Local Landscape: Pioneer Log Buildings.

    Science.gov (United States)

    Douglas, Bob; And Others

    Building structures made from logs appeared in the eastern United States during the late 17th century, and immigrants from Sweden, Finland, and Germany are credited with their construction. There were two types of structures: the horizontal design introduced by the Scandinavians and the German or Pennsylvania Dutch model that was used by the…

  6. 32 CFR 700.846 - Status of logs.

    Science.gov (United States)

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Status of logs. 700.846 Section 700.846 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND... Officers Afloat § 700.846 Status of logs. The deck log, the engineering log, the compass record,...

  7. 47 CFR 73.782 - Retention of logs.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Retention of logs. 73.782 Section 73.782... International Broadcast Stations § 73.782 Retention of logs. Logs of international broadcast stations shall be retained by the licensee or permittee for a period of two years: Provided, however, That logs...

  8. 47 CFR 73.1840 - Retention of logs.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Retention of logs. 73.1840 Section 73.1840... Rules Applicable to All Broadcast Stations § 73.1840 Retention of logs. (a) Any log required to be kept by station licensees shall be retained by them for a period of 2 years. However, logs...

  9. Performance of sampling methods to estimate log characteristics for wildlife.

    Science.gov (United States)

    Lisa J. Bate; Torolf R. Torgersen; Michael J. Wisdom; Edward O. Garton

    2004-01-01

    Accurate estimation of the characteristics of log resources, or coarse woody debris (CWD), is critical to effective management of wildlife and other forest resources. Despite the importance of logs as wildlife habitat, methods for sampling logs have traditionally focused on silvicultural and fire applications. These applications have emphasized estimates of log volume...

  10. Cosolvency and deviations from log-linear solubilization.

    Science.gov (United States)

    Rubino, J T; Yalkowsky, S H

    1987-06-01

    The solubilities of three nonpolar drugs, phenytoin, diazepam, and benzocaine, have been measured in 14 cosolvent-water binary mixtures. The observed solubilities were examined for deviations from solubilities calculated by the equation log Sm = f log Sc + (1 - f) log Sw, where Sm is the solubility of the drug in the cosolvent-water mixture, Sc is the solubility of the drug in neat cosolvent, f is the volume fraction of cosolvent, and Sw is the solubility of the drug in water. When presented graphically, the patterns of the deviations were similar for all three drugs in mixtures of amphiprotic cosolvents (glycols, polyols, and alcohols) and water as well as nonpolar, aprotic cosolvents (dioxane, triglyme, dimethyl isosorbide) and water. The deviations were positive for phenytoin and benzocaine but negative for diazepam in mixtures of dipolar, aprotic cosolvents (dimethylsulfoxide, dimethylformamide, and dimethylacetamide) and water. The source of the deviations could not consistently be attributed to physical properties of the cosolvent-water mixtures or to alterations in the solute crystal. Similarities between the results of this study and those of previous investigations suggest that changes in the structure of the solvent play a role in the deviations from the expected solubilities.

  11. Logging Geology Study of the Caverned Paleokarst Reservoir Distribution

    Institute of Scientific and Technical Information of China (English)

    WuXinsong; YangLei; PanWenqing; GuQiaoyuan

    2005-01-01

    In recent years, many carbonate rock oilfields such as Lunnan and Tahe have been found in the Tarim Basin, and the main reservoir space of the stable high yield wells in these oilfields consists mainly of the caverns formed by the paleo-karstification and the dissolution pores and fractures connected with them. Nevertheless, it is difficult to predict effectively the distribution of the cavern reservoir because of its extremely serious heterogeneity. In this paper, a case study of the Lunxi Oilfield in the north uplift of the Tarim Basin is conducted to introduce the logging geology method for predicting the distribution of the caverned paleokarst, reservoir. By means of building up the logging recognition style of different caverns and differentiating and correlating the karst zones with logging curves, and through an analysis of the paleokarst topography background, the favorable karst zones and distribution areas of the high quality cavern reservoir have been located, which lays a new basis for further exploration in this area.

  12. Requirements-Driven Log Analysis Extended Abstract

    Science.gov (United States)

    Havelund, Klaus

    2012-01-01

    Imagine that you are tasked to help a project improve their testing effort. In a realistic scenario it will quickly become clear, that having an impact is diffcult. First of all, it will likely be a challenge to suggest an alternative approach which is significantly more automated and/or more effective than current practice. The reality is that an average software system has a complex input/output behavior. An automated testing approach will have to auto-generate test cases, each being a pair (i; o) consisting of a test input i and an oracle o. The test input i has to be somewhat meaningful, and the oracle o can be very complicated to compute. Second, even in case where some testing technology has been developed that might improve current practice, it is then likely difficult to completely change the current behavior of the testing team unless the technique is obviously superior and does everything already done by existing technology. So is there an easier way to incorporate formal methods-based approaches than the full edged test revolution? Fortunately the answer is affirmative. A relatively simple approach is to benefit from possibly already existing logging infrastructure, which after all is part of most systems put in production. A log is a sequence of events, generated by special log recording statements, most often manually inserted in the code by the programmers. An event can be considered as a data record: a mapping from field names to values. We can analyze such a log using formal methods, for example checking it against a formal specification. This separates running the system for analyzing its behavior. It is not meant as an alternative to testing since it does not address the important in- put generation problem. However, it offers a solution which testing teams might accept since it has low impact on the existing process. A single person might be assigned to perform such log analysis, compared to the entire testing team changing behavior.

  13. Seasonal logging, process response, and geomorphic work

    Science.gov (United States)

    Mohr, C. H.; Zimmermann, A.; Korup, O.; Iroumé, A.; Francke, T.; Bronstert, A.

    2013-09-01

    Deforestation is a prominent anthropogenic cause of erosive overland flow and slope instability, boosting rates of soil erosion and concomitant sediment flux. Conventional methods of gauging or estimating post-logging sediment flux focus on annual timescales, but potentially overlook important geomorphic responses on shorter time scales immediately following timber harvest. Sediments fluxes are commonly estimated from linear regression of intermittent measurements of water and sediment discharge using sediment rating curves (SRCs). However, these often unsatisfactorily reproduce non-linear effects such as discharge-load hystereses. We resolve such important dynamics from non-parametric Quantile Regression Forests (QRF) of high-frequency (3 min) measurements of stream discharge and sediment concentrations in similar-sized (~ 0.1 km2) forested Chilean catchments that were logged during either the rainy or the dry season. The method of QRF builds on the Random Forest (RF) algorithm, and combines quantile regression with repeated random sub-sampling of both cases and predictors. The algorithm belongs to the family of decision-tree classifiers, which allow quantifying relevant predictors in high-dimensional parameter space. We find that, where no logging occurred, ~ 80% of the total sediment load was transported during rare but high magnitude runoff events during only 5% of the monitoring period. The variability of sediment flux of these rare events spans four orders of magnitude. In particular dry-season logging dampened the role of these rare, extreme sediment-transport events by increasing load efficiency during more moderate events. We show that QRFs outperforms traditional SRCs in terms of accurately simulating short-term dynamics of sediment flux, and conclude that QRF may reliably support forest management recommendations by providing robust simulations of post-logging response of water and sediment discharge at high temporal resolution.

  14. Requirements-Driven Log Analysis Extended Abstract

    Science.gov (United States)

    Havelund, Klaus

    2012-01-01

    Imagine that you are tasked to help a project improve their testing effort. In a realistic scenario it will quickly become clear, that having an impact is diffcult. First of all, it will likely be a challenge to suggest an alternative approach which is significantly more automated and/or more effective than current practice. The reality is that an average software system has a complex input/output behavior. An automated testing approach will have to auto-generate test cases, each being a pair (i; o) consisting of a test input i and an oracle o. The test input i has to be somewhat meaningful, and the oracle o can be very complicated to compute. Second, even in case where some testing technology has been developed that might improve current practice, it is then likely difficult to completely change the current behavior of the testing team unless the technique is obviously superior and does everything already done by existing technology. So is there an easier way to incorporate formal methods-based approaches than the full edged test revolution? Fortunately the answer is affirmative. A relatively simple approach is to benefit from possibly already existing logging infrastructure, which after all is part of most systems put in production. A log is a sequence of events, generated by special log recording statements, most often manually inserted in the code by the programmers. An event can be considered as a data record: a mapping from field names to values. We can analyze such a log using formal methods, for example checking it against a formal specification. This separates running the system for analyzing its behavior. It is not meant as an alternative to testing since it does not address the important in- put generation problem. However, it offers a solution which testing teams might accept since it has low impact on the existing process. A single person might be assigned to perform such log analysis, compared to the entire testing team changing behavior.

  15. ANALYSIS OF USING EFFICIENT LOGGING TOOLS AT PT. PURWA PERMAI IN CENTRAL KALIMANTAN

    OpenAIRE

    Sona Suhartana; Yuniawati Yuniawati

    2008-01-01

    A high log demand that often exceeds its supply capability should be overcome by using appropriate logging  tools. Numerous  kinds and types of logging  tools require  a well planning in their utilization. Number of tools which are greater or fewer than what is actually needed can be disadvantageous  for a company. In relevant to these aspects, a study was carried out at a timber estate in Central Kalimantan  in 2007. The aim of the study was to find out an efficient number  of tools used for...

  16. Coal log pipeline research at the University of Missouri. 4th Quarterly report, October 1, 1993--December 31, 1993

    Energy Technology Data Exchange (ETDEWEB)

    Liu, H.

    1994-05-01

    This paper is a progress report on a research project aimed at the development of coal log technology. Efforts have been directed at the development of technology for the fabrication of stable coal logs, as well as the energy efficient transport of these logs, in particular by pipelines. Work has been directed at new types of binders, new fabrication presses, the application of polymers to reduce transport losses, and modeling efforts.

  17. Effect of Logging Operation on Soil Carbon Storage of a Tropical Peat Swamp Forest

    Directory of Open Access Journals (Sweden)

    Anton E. Satrio

    2009-01-01

    Full Text Available Problem statement: Since heavy machinery are used in the logging operation activity for extracting the logs on sensitive forest site with peat soil, environment destruction should be the other concern during its processes especially on its important function as soil carbon storage. The objective of this study was to determine whether logging operation affect soil carbon storage of a tropical peat swamp forest. Approach: Soil sampling was conducted before and after logging operation in a 0.3 ha plot to a depth of 15 cm. The soil samples were analyzed for acidity, organic matter content, total carbon, total nitrogen and total phosphorus. The humic acid extraction was also done and soil carbon storage values were obtained by calculation. Paired t-test was used to compare variables under the two treatments (before and after logging and correlation analysis was used to correlate variables such as soil pH, soil organic matter, total carbon, total nitrogen, total phosphorus, C/N ratio, C/P ratio, humic acid yield, unstable carbon and stable carbon. Results: The availability of unstable carbon and stable carbon controlled by soil acidity on undisturbed peat swamp forest as a result, the accumulation of unstable carbon as well as stable carbon occurred even if the soil pH declines and vice versa. However, stable carbon associated well with soil acidity. It was found that the C/P ratio positively correlated with humic acid and stable carbon of both before and after logging conditions. Nevertheless, that association was prominent on logged peat swamp forest. An indication that even though this peat swamp forest had been logged, humification was strongly maintained. However, the similarity of stable carbon of the logged peat swamp forest with stable carbon of undisturbed peat swamp forest indicate an ineffectiveness humification of logged peat swamp forest. Conclusion: Logging operation on sensitive forest with peat soil using heavy machinery increased the

  18. Monte Carlo Numerical Models for Nuclear Logging Applications

    OpenAIRE

    Fusheng Li; Xiaogang Han

    2012-01-01

    Nuclear logging is one of most important logging services provided by many oil service companies. The main parameters of interest are formation porosity, bulk density, and natural radiation. Other services are also provided from using complex nuclear logging tools, such as formation lithology/mineralogy, etc. Some parameters can be measured by using neutron logging tools and some can only be measured by using a gamma ray tool. To understand the response of nuclear logging tools, the neutron t...

  19. Dissociation behavior of Methane Hydrate presumed by NMR log analysis

    Science.gov (United States)

    Kotera, T.

    2015-12-01

    This study has been conducted with the aim of comprehending dissociation behavior of MH. The production test was operated in the Daini-Atsumi knoll in the eastern Nankai Trough, Japan. We corresponded the NMR log data acquired from the three wells, which drilled before the test (AT1-MC) and after the test (AT1-LWD1 and AT1-LWD2). NMR log measures T2 relaxation time, and calculates porosity and permeability. We especially focused on the T2 distribution. It is assumed that MH occupied larger pore space in the sandy sediment because the T2 distribution in the MH bearing layer has no peak in the longer time zone at the AT1-MC. However, T2 peak appeared over 33ms zone at the AT1-LWD1 and AT1-LWD2. This phenomenon is observed in the thin MH bearing layers rather than thick one. On the other hand, nothing T2 peak appeared over the 33ms zone in the thick MH bearing layer, but T2 distribution shifts to longer relaxation time in the short time interval. Hence, it is assumed that the MH was dissociated from the contact faces with the grain. In terms of the thermal conductivity, near the grain-grain contact faces are more dissociable than the MH-grain contact; however both of dissociation zones are essentially MH-grain contact faces. Nothing or few MH was observed in the muddy layer at the coring campaign near these wells. Abovementioned, NMR logging detected various changes on the T2 distribution. It seems to indicate the dissociation of MH. And these data gets into alignment with other log data and monitoring data, which are resistivity and temperature measurement. However, as this logging data acquired from each location, there is possibility that the initial condition was originally distinct. This research was conducted as a part of the MH21 research, and the authors would like to express their sincere appreciation to MH21 and the Ministry of Economy, Trade and Industry for providing the permission to disclose this research.

  20. 测井资料 Xu-White 模型预测横波速度的一些新观点%New Viewpoints on S-wave Velocity Prediction Using Xu-White Model Based on Well Logging Data

    Institute of Scientific and Technical Information of China (English)

    石双虎; 邓志文; 白光宇; 李红星; 蔡敏贵

    2015-01-01

    目前横波预测的方法大致可以分为两种:经验公式预测和理论岩石物理模型。由于经验公式预测一般具有区域性,研究者更重视岩石物理模型预测。目前大多数岩石物理模型预测横波的方法假定地下流体的物性参数(速度和密度)不受地层深度的影响,且孔隙扁率是恒定的,实际上这并不科学。因为矿物的体积模量和剪切模量随所处地层深度发生改变,而对于孔隙扁率则随颗粒形状、孔隙度等的变化有较大变化。针对这些情况,提出一种新的改进的Xu-White横波预测方法,并可取得较好的效果。%Physical quantities such as the Poisson ratio and Lame modulus,which represent fluid properties,can be obtained using S-wave velocity.These parameters can be used to reduce the multiple interpretations of seismic amplitudes.Thus,although it is very important to use S-wave velocity in performing seismic data AVO analysis,prestack inversion,and fluid identification, there is seldom information about this velocity in actual logging data.Currently,methods for S-wave velocity prediction can be divided into two types:empirical formula method and theoretical rock-physics-model-prediction method.The former is simple,limited to some exploration area, and requires larger workloads to increase its general overall applicability.Compared with the em-pirical formula method,the rock physics model method is complex,but it has universal applica-tion in different areas.Most rock physics model methods for predicting S-wave velocity assume that the physical parameters of an underground fluid (velocity and density)are not affected by the depth of the stratum or pore aspect ratio.However,this is not a valid assumption even for the most popular rock physics model,the Xu-White model.In fact,the bulk modulus and shear mod-ulus of minerals change with the depth of a reservoir.For fluid parameters,this type of effect will increase.With respect to the

  1. Structural basis for cytokinin production by LOG from Corynebacterium glutamicum.

    Science.gov (United States)

    Seo, Hogyun; Kim, Sangwoo; Sagong, Hye-Young; Son, Hyeoncheol Francis; Jin, Kyeong Sik; Kim, Il-Kwon; Kim, Kyung-Jin

    2016-08-10

    "Lonely guy" (LOG) has been identified as a cytokinin-producing enzyme in plants and plant-interacting fungi. The gene product of Cg2612 from the soil-dwelling bacterium Corynebacterium glutamicum was annotated as an LDC. However, the facts that C. glutamicum lacks an LDC and Cg2612 has high amino acid similarity with LOG proteins suggest that Cg2612 is possibly an LOG protein. To investigate the function of Cg2612, we determined its crystal structure at a resolution of 2.3 Å. Cg2612 functions as a dimer and shows an overall structure similar to other known LOGs, such as LOGs from Arabidopsis thaliana (AtLOG), Claviceps purpurea (CpLOG), and Mycobacterium marinum (MmLOG). Cg2612 also contains a "PGGXGTXXE" motif that contributes to the formation of an active site similar to other LOGs. Moreover, biochemical studies on Cg2612 revealed that the protein has phosphoribohydrolase activity but not LDC activity. Based on these structural and biochemical studies, we propose that Cg2612 is not an LDC family enzyme, but instead belongs to the LOG family. In addition, the prenyl-binding site of Cg2612 (CgLOG) comprised residues identical to those seen in AtLOG and CpLOG, albeit dissimilar to those in MmLOG. The work provides structural and functional implications for LOG-like proteins from other microorganisms.

  2. An Approach to Log Management: Prototyping a Design of Agent for Log Harvesting

    CERN Document Server

    Reinaldo, Mayol Arnao; Antonio, Lobo

    2011-01-01

    This paper describes a work in progress implementing a solution for harvesting and transporting information logs from network devices in a e-science environment. The system is composed for servers, agents, active devices and a transporting protocol. This document describes the state of development of agents. Agents capture logs from devices, normalize, reduce and cataloged them by using metadata. Once all these processes are done, they transmit the cataloged data by using Transportation Protocol to a warehouse server. Also an agent use orchestration parameters to transmit modified logs to a data warehouse server. These parameters can be received from orchestration applications such as Taverna. The operation of the agents and the communication protocol solve some of the deficiencies of traditional logs management protocols. Finally, we show some test realized over the new prototype.

  3. Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and analysis

    Science.gov (United States)

    Collett, Timothy S.; Lee, Wyung W.; Zyrianova, Margarita V.; Mrozewski, Stefan A.; Guerin, Gilles; Cook, Ann E.; Goldberg, Dave S.

    2012-01-01

    One of the objectives of the Gulf of Mexico Gas Hydrate Joint Industry Project Leg II (GOM JIP Leg II) was the collection of a comprehensive suite of logging-while-drilling (LWD) data within gas-hydrate-bearing sand reservoirs in order to make accurate estimates of the concentration of gas hydrates under various geologic conditions and to understand the geologic controls on the occurrence of gas hydrate at each of the sites drilled during this expedition. The LWD sensors just above the drill bit provided important information on the nature of the sediments and the occurrence of gas hydrate. There has been significant advancements in the use of downhole well-logging tools to acquire detailed information on the occurrence of gas hydrate in nature: From using electrical resistivity and acoustic logs to identify gas hydrate occurrences in wells to where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gas hydrate reservoirs and the distribution and concentration of gas hydrates within various complex reservoir systems. Recent integrated sediment coring and well-log studies have confirmed that electrical resistivity and acoustic velocity data can yield accurate gas hydrate saturations in sediment grain supported (isotropic) systems such as sand reservoirs, but more advanced log analysis models are required to characterize gas hydrate in fractured (anisotropic) reservoir systems. In support of the GOM JIP Leg II effort, well-log data montages have been compiled and presented in this report which includes downhole logs obtained from all seven wells drilled during this expedition with a focus on identifying and characterizing the potential gas-hydrate-bearing sedimentary section in each of the wells. Also presented and reviewed in this report are the gas-hydrate saturation and sediment porosity logs for each of the wells as calculated from available downhole well logs.

  4. Gulf of Mexico Gas Hydrate Joint Industry Project Leg II logging-while-drilling data acquisition and anaylsis

    Science.gov (United States)

    Collett, Timothy S.; Lee, Myung W.; Zyrianova, Margarita V.; Mrozewski, Stefan A.; Guerin, Gilles; Cook, Ann E.; Goldberg, Dave S.

    2012-01-01

    One of the objectives of the Gulf of MexicoGasHydrateJointIndustryProjectLegII (GOM JIP LegII) was the collection of a comprehensive suite of logging-while-drilling (LWD) data within gas-hydrate-bearing sand reservoirs in order to make accurate estimates of the concentration of gashydrates under various geologic conditions and to understand the geologic controls on the occurrence of gashydrate at each of the sites drilled during this expedition. The LWD sensors just above the drill bit provided important information on the nature of the sediments and the occurrence of gashydrate. There has been significant advancements in the use of downhole well-logging tools to acquire detailed information on the occurrence of gashydrate in nature: From using electrical resistivity and acoustic logs to identify gashydrate occurrences in wells to where wireline and advanced logging-while-drilling tools are routinely used to examine the petrophysical nature of gashydrate reservoirs and the distribution and concentration of gashydrates within various complex reservoir systems. Recent integrated sediment coring and well-log studies have confirmed that electrical resistivity and acoustic velocity data can yield accurate gashydrate saturations in sediment grain supported (isotropic) systems such as sand reservoirs, but more advanced log analysis models are required to characterize gashydrate in fractured (anisotropic) reservoir systems. In support of the GOM JIP LegII effort, well-log data montages have been compiled and presented in this report which includes downhole logs obtained from all seven wells drilled during this expedition with a focus on identifying and characterizing the potential gas-hydrate-bearing sedimentary section in each of the wells. Also presented and reviewed in this report are the gas-hydrate saturation and sediment porosity logs for each of the wells as calculated from available downhole well logs.

  5. A risk index for multicriterial selection of a logging system with low environmental impact

    Energy Technology Data Exchange (ETDEWEB)

    Horodnic, Sergiu Andrei, E-mail: horodnic@usv.ro

    2015-02-15

    Setting up the working stages in forest operations is conditioned by environmental protection and forest health requirements. This paper exposes a method for improving the decision-making process by choosing the most environmentally effective logging systems according to terrain configuration and stand characteristics. Such a methodology for selecting machines or logging systems accounting for environment, safety as well as economics, becomes mandatory in the context of sustainable management of forest with multiple functions. Based on analytic hierarchy process analysis the following classification of the environmental performance for four considered alternatives was obtained: skyline system (42.43%), forwarder system (20.22%), skidder system (19.92%) and horse logging system (17.43%). Further, an environmental risk matrix for the most important 28 risk factors specific to any work equipment used in forest operations was produced. In the end, a multicriterial analysis generated a risk index RI ranging between 1.0 and 3.5, which could help choosing the optimal combination of logging system and logging equipment with low environmental impact. In order to demonstrate the usefulness of the proposed approach, a simple application in specific conditions of a harvesting site is presented. - Highlights: • We propose a decision-making algorithm to select eco-friendly logging systems. • Analytic hierarchy process was applied for ranking 4 types of logging systems. • An environmental risk matrix with 28 risk factors in forest operations was made up.

  6. Contrast Invariant Interest Point Detection by Zero-Norm LoG Filter.

    Science.gov (United States)

    Zhenwei Miao; Xudong Jiang; Kim-Hui Yap

    2016-01-01

    The Laplacian of Gaussian (LoG) filter is widely used in interest point detection. However, low-contrast image structures, though stable and significant, are often submerged by the high-contrast ones in the response image of the LoG filter, and hence are difficult to be detected. To solve this problem, we derive a generalized LoG filter, and propose a zero-norm LoG filter. The response of the zero-norm LoG filter is proportional to the weighted number of bright/dark pixels in a local region, which makes this filter be invariant to the image contrast. Based on the zero-norm LoG filter, we develop an interest point detector to extract local structures from images. Compared with the contrast dependent detectors, such as the popular scale invariant feature transform detector, the proposed detector is robust to illumination changes and abrupt variations of images. Experiments on benchmark databases demonstrate the superior performance of the proposed zero-norm LoG detector in terms of the repeatability and matching score of the detected points as well as the image recognition rate under different conditions.

  7. Forecasting Monthly Prices of Japanese Logs

    Directory of Open Access Journals (Sweden)

    Tetsuya Michinaka

    2016-04-01

    Full Text Available Forecasts of prices can help industries in their risk management. This is especially true for Japanese logs, which experience sharp fluctuations in price. In this research, the authors used an exponential smoothing method (ETS and autoregressive integrated moving average (ARIMA models to forecast the monthly prices of domestic logs of three of the most important species in Japan: sugi (Japanese cedar, Cryptomeria japonica D. Don, hinoki (Japanese cypress, Chamaecyparis obtusa (Sieb. et Zucc. Endl., and karamatsu (Japanese larch, Larix kaempferi (Lamb. Carr.. For the 12-month forecasting periods, forecasting intervals of 80% and 95% were given. By measuring the accuracy of forecasts of 12- and 6-month forecasting periods, it was found that ARIMA gave better results than did the ETS in the majority of cases. However, the combined method of averaging ETS and ARIMA forecasts gave the best results for hinoki in several cases.

  8. CS model coil experimental log book

    Energy Technology Data Exchange (ETDEWEB)

    Nishijima, Gen; Sugimoto, Makoto; Nunoya, Yoshihiko; Wakabayashi, Hiroshi; Tsuji, Hiroshi [Japan Atomic Energy Research Inst., Naka, Ibaraki (Japan). Naka Fusion Research Establishment

    2001-02-01

    Charging test of the ITER CS Model Coil which is the world's largest superconducting pulse coil and the CS Insert Coil had started at April 11, 2000 and had completed at August 18, 2000. In the campaign, total shot numbers were 356 and the size of the data file in the DAS (Data Acquisition System) was over 20 GB. This report is a database that consists of the log list and the log sheets of every shot. One can access the database, make a search, and browse results via Internet (http://1ogwww.naka.jaeri.go.jp). The database will be useful to quick search to choose necessary shots. (author)

  9. SNG-log in borehole Ermelund-208

    DEFF Research Database (Denmark)

    Korsbech, Uffe C C

    1996-01-01

    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 a si......-rays are emitted and detected by the probe. The intensity of cosmic radiation varies with depth, and, therefore, slightly influences the accuracy of the thorium concentration determination.......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...

  10. Log evaluation of fractured igneous reservoirs in Songliao Basin

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    The petrophysical parameters are bad in most igneous reservoirs of Songliao Basin because of the very low porosity and permeability. The evaluation of igneous reservoirs has not been fully studied so far. The current technique of formation evaluation and interpretation used in sedimentary formations face a series of problems and difficulties. In this study, The PCA was used to identify lithology, a multi-mineral model "QAPM" was proposed. "Surface effect" must be considered when evaluating saturation. A software "SIMPLE" was developed and was used to deal with the logging data in over 70 wells with good results were achieved.

  11. Effects of Selection Logging on Rainforest Productivity

    OpenAIRE

    Vanclay, Jerome K.

    2006-01-01

    An analysis of data from 212 permanent sample plots provided no evidence of any decline in rainforest productivity after three cycles of selection logging in the tropical rainforests of north Queensland. Relative productivity was determined as the difference between observed diameter increments and increments predicted from a diameter increment function which incorporated tree size, stand density and site quality. Analyses of variance and regression analyses revealed no significant decline in...

  12. Using Web Logs in the Science Classroom

    Science.gov (United States)

    Duplichan, Staycle C.

    2009-01-01

    As educators we must ask ourselves if we are meeting the needs of today's students. The science world is adapting to our ever-changing society; are the methodology and philosophy of our educational system keeping up? In this article, you'll learn why web logs (also called blogs) are an important Web 2.0 tool in your science classroom and how they…

  13. Log-scaling magnitude modulated watermarking scheme

    Institute of Scientific and Technical Information of China (English)

    LING HeFei; YUAN WuGang; ZOU FuHao; LU ZhengDing

    2007-01-01

    A real-time watermarking scheme with high robustness and security has been proposed based on modulating the log-scaling magnitudes of DCT coefficients,which is most suitable for JPEG images and MPEG streams. The watermark bit is encoded as the sign of the difference between the individual log-scaling magnitude of a group-region and the average one of all group-regions. The log-scaling magnitude can be modulated by modifying the low and middle frequency DCT coefficients imperceptibly. The robustness of scheme is not only dependent on those largest coefficients, but also on the other coefficients with the same proportion. It can embed 512 bits into an image with a size of 512×512, which can satisfy the payload requirement of most video watermarking applications. Moreover, the watermark embedding process only requires one-sixth of the time consumed during normal playing of video, and the watermark detection only requires one-twelfth of that, which can meet the real-time requirements of most video watermarking applications. Furthermore, the experimental results show that the presented scheme is transparent and robust to significant valumetric distortions (including additive noise, low-pass filtering, lossy compression and valumetric scaling) and a part of geometric distortions. It performs much better than the EMW algorithm in resisting all kinds of distortions except Gaussian noise with a larger deviation.

  14. Gerencia logística y global

    Directory of Open Access Journals (Sweden)

    Pablo Cesar Ocampo Vélez

    2009-04-01

    Full Text Available La logística es una filosofía que se encarga de aplicar las buenas pá¡cticas en los macroprocesos, procesos, procedimientos, tareas y productos dentro de una organización, con el fin de satisfacer las necesidades del cliente, quien es la razón de ser de la empresa. Existen entes internacionales que velan porque las compañias en todo el mundo utilicen y difundan las diferentes disciplinas logísticas en toda la red de valor y tengan un mismo enfoque estratégico.El objetivo de este artículo es explicar la existencia de procesos y macroprocesos de clase mundial en la logística, gracias a los cuales hay una gran oportunidad de mejora para los empresarios colombianos, con el fin de reestructurar los procesos estratégicos, tácticos y operacionales de cada Unidad de Negocio, para que sean organizaciones más competitivas, que puedan enfrentar los tratados de libre comercio, brindando mayor sostenibilidad y óptimo nivel de servicio.

  15. Militantly Well

    DEFF Research Database (Denmark)

    Vigh, Henrik Erdman

    2015-01-01

    futures that transcend conflict engagement and wartime suffering for young militiamen. It clarifies the positive prospects that are expected to lie beyond the known horrors of war. Though conflict and warfare may provide strange points of departure for talking about well-being, imaginaries of happiness...... stand out from a background of hardship and are talked about in both a quite concrete way, as a lack of insecurity, as well as in an abstract way, as realization of social being. However, for most of the people I talk to, happiness remains elusive and evades their desperate attempts to grasp it....... It appears, as such, simultaneously to be what life is most profoundly about, as well as the dimension of it that constantly seems to avoid capture....

  16. Oil spill characterization in the hybrid polarity SAR domain using log-cumulants

    Science.gov (United States)

    Espeseth, Martine M.; Skrunes, Stine; Brekke, Camilla; Salberg, Arnt-Børre; Jones, Cathleen E.; Holt, Benjamin

    2016-10-01

    Log-cumulants have proven to be an interesting tool for evaluating the statistical properties of potential oil spills in polarimetric Synthetic Aperture Radar (SAR) data within the common horizontal (H) and vertical (V) polarization basis. The use of first, second, and third order sample log-cumulants has shown potential for evaluating the texture and the statistical distributions, as well as discriminating oil from look-alikes. Log-cumulants are cumulants derived in the log-domain and can be applied to both single-polarization and multipolarization SAR data. This study is the first to investigate the differences between hybrid-polarity (HP) and full-polarimetric (FP) modes based on the sample log-cumulants of various oil slicks and open water from nine Uninhabited Aerial Vehicle Synthetic Aperture Radar (UAVSAR) scenes acquired off the coast of Norway in 2015. The sample log-cumulants calculated from the HP intensities show similar statistical behavior to the FP ones, resulting in a similar interpretation of the sample log-cumulants from HP and FP. Approximately eight hours after release the sample log-cumulants representing emulsion slicks have become more similar to the open water compared to plant oil. We find that the sample log-cumulants of the various oil slicks and open water varies between the scenes and also between the slicks and open water. This might be due to changes in ocean and wind condition, the initial slick properties, and/or the difference in the weathering process of the oil slicks.

  17. Multiple Patterns of Forest Disturbance and Logging Shape Forest Landscapes in Paragominas, Brazil

    Directory of Open Access Journals (Sweden)

    Isabelle Tritsch

    2016-12-01

    Full Text Available In the Brazilian Amazon, multiple logging activities are undergoing, involving different actors and interests. They shape a disturbance gradient bound to the intensity and frequency of logging, and forest management techniques. However, until now, few studies have been carried out at the landscape scale taking into account these multiple types of logging and this disturbance gradient. Here we address this issue of how to account for the multiple logging activities shaping the current forest landscape. We developed an inexpensive and efficient remote sensing methodology based on Landsat imagery to detect and track logging activity based on the monitoring of canopy openings. Then, we implemented a set of remote sensing indicators to follow the different trajectories of forest disturbance through time. Using these indicators, we emphasized five major spatial and temporal disturbance patterns occurring in the municipality of Paragominas (State of Pará, Brazilian Amazon, from well-managed forests to highly over-logged forests. Our disturbance indicators provide observable evidence for the difference between legal and illegal patterns, with some illegal areas having suffered more than three explorations in fifteen years. They also clearly underlined the efficiency of Reduced Impact Logging (RIL techniques applied under Forest Stewardship Council (FSC guidelines to reduce the logging impacts in terms of canopy openings. For these reasons, we argue the need to promote legal certified logging to conserve forests, as without them, many actors mine the forest resources without any concerns for future stocks. Finally, our remote tracking methodology, which produces easy to interpret disturbance indicators, could be a real boon to forest managers, including for conservationists working in protected areas and stakeholders dealing with international trade rules such as RBUE (Wood regulation of European Union or FLEGT (Forest Law for Enforcement, Governance

  18. Reduced-impact logging and biodiversity conservation: a case study from Borneo.

    Science.gov (United States)

    Edwards, David P; Woodcock, Paul; Edwards, Felicity A; Larsen, Trond H; Hsu, Wayne W; Benedick, Suzan; Wilcove, David S

    2012-03-01

    A key driver of rain forest degradation is rampant commercial logging. Reduced-impact logging (RIL) techniques dramatically reduce residual damage to vegetation and soils, and they enhance the long-term economic viability of timber operations when compared to conventionally managed logging enterprises. Consequently, the application of RIL is increasing across the tropics, yet our knowledge of the potential for RIL also to reduce the negative impacts of logging on biodiversity is minimal. We compare the impacts of RIL on birds, leaf-litter ants, and dung beetles during a second logging rotation in Sabah, Borneo, with the impacts of conventional logging (CL) as well as with primary (unlogged) forest. Our study took place 1-8 years after the cessation of logging. The species richness and composition of RIL vs. CL forests were very similar for each taxonomic group. Both RIL and CL differed significantly from unlogged forests in terms of bird and ant species composition (although both retained a large number of the species found in unlogged forests), whereas the composition of dung beetle communities did not differ significantly among forest types. Our results show little difference in biodiversity between RIL and CL over the short-term. However, biodiversity benefits from RIL may accrue over longer time periods after the cessation of logging. We highlight a severe lack of studies investigating this possibility. Moreover, if RIL increases the economic value of selectively logged forests (e.g., via REDD+, a United Nations program: Reducing Emissions from Deforestation and Forest Degradation in Developing Countries), it could help prevent them from being converted to agricultural plantations, which results in a tremendous loss of biodiversity.

  19. Log-periodic route to fractal functions.

    Science.gov (United States)

    Gluzman, S; Sornette, D

    2002-03-01

    Log-periodic oscillations have been found to decorate the usual power-law behavior found to describe the approach to a critical point, when the continuous scale-invariance symmetry is partially broken into a discrete-scale invariance symmetry. For Ising or Potts spins with ferromagnetic interactions on hierarchical systems, the relative magnitude of the log-periodic corrections are usually very small, of order 10(-5). In growth processes [diffusion limited aggregation (DLA)], rupture, earthquake, and financial crashes, log-periodic oscillations with amplitudes of the order of 10% have been reported. We suggest a "technical" explanation for this 4 order-of-magnitude difference based on the property of the "regular function" g(x) embodying the effect of the microscopic degrees of freedom summed over in a renormalization group (RG) approach F(x)=g(x)+mu(-1)F(gamma x) of an observable F as a function of a control parameter x. For systems for which the RG equation has not been derived, the previous equation can be understood as a Jackson q integral, which is the natural tool for describing discrete-scale invariance. We classify the "Weierstrass-type" solutions of the RG into two classes characterized by the amplitudes A(n) of the power-law series expansion. These two classes are separated by a novel "critical" point. Growth processes (DLA), rupture, earthquake, and financial crashes thus seem to be characterized by oscillatory or bounded regular microscopic functions that lead to a slow power-law decay of A(n), giving strong log-periodic amplitudes. If in addition, the phases of A(n) are ergodic and mixing, the observable presents self-affine nondifferentiable properties. In contrast, the regular function of statistical physics models with "ferromagnetic"-type interactions at equilibrium involves unbound logarithms of polynomials of the control variable that lead to a fast exponential decay of A(n) giving weak log-periodic amplitudes and smoothed observables.

  20. Liver Wellness

    Science.gov (United States)

    ... can cause the liver to swell and not work well. Prevention: Hepatitis A vaccination is the best way to prevent HAV. Other ways to stop the spread of HAV are: • Always washing your hands with soap and warm water immediately after using the bathroom ...