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Sample records for well logging equipment

  1. Tests pits for calibrating well logging equipment in fractured hard-rock environment

    SciTech Connect

    Mathews, M.A.; Scott, J.H.; LaDelfe, C.M.

    1985-01-01

    The calibration facility consists of three pits containing fine-grained granite, coarse-grained granite, and medium-grained metamorphosed granodiorite. Each pit contains large quarried blocks of rock that are 8 ft octagons and form a 20 ft stack. The blocks are saturated with water and sealed in watertight fiberglass containers that are recessed so that the top of the upper block is approximately level with the ground. The blocks contain simulated fractures that are formed by the joints between the blocks and by saw cuts at several locations. Cored boreholes through the blocks are 7 7/8 in. in diameter, with a fiberglass-cased ''rat hole'' extending 30 ft below the bottom block. Laboratory and well logging studies (United States Geological Society, Schlumberger, and Dresser Atlas logs) have been made to determine the physical properties of rocks in the three pits, and preliminary results are reported. Porosities of individual samples (core measurements) taken at 1 ft intervals in the three pits range from 0.00 to 0.90%, densities from 2.64 to 2.79 g/cm/sup 3/, and sonic velocities from 18,700 to 22,500 ft/sec. Radio-element of individual samples (core measurements) taken at 5 ft intervals from these test pits range from 0.62 to 4.08% K (potassium) content, from 0.34 to 5.01 ppM RaeU (uranium) content and from 0.46 to 19.6 ppM Th (thorium) content. Access to the pits for calibrating well logging equipment can be arranged by contacting the United States Geological Survey (phone number 303-236-5913) in Denver, Colorado. 4 refs., 38 figs., 4 tabs.

  2. Well Log ETL tool

    SciTech Connect

    Good, Jessica

    2013-08-01

    This is an executable python script which offers two different conversions for well log data: 1) Conversion from a BoreholeLASLogData.xls model to a LAS version 2.0 formatted XML file. 2) Conversion from a LAS 2.0 formatted XML file to an entry in the WellLog Content Model. Example templates for BoreholeLASLogData.xls and WellLogsTemplate.xls can be found in the package after download.

  3. Well Logging with Californium-252

    SciTech Connect

    Boulogne, A.R.

    2003-01-06

    Californium-252 is an intense neutron emitter that has only recently become available for experimental well logging. The purpose of this research is to investigate the application of well logging to groundwater hydrology; however, most of the techniques and purposes are quite similar to applications in the petroleum industry.

  4. Chemical logging of geothermal wells

    DOEpatents

    Allen, Charles A.; McAtee, Richard E.

    1981-01-01

    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.

  5. Chemical logging of geothermal wells

    DOEpatents

    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.

  6. 21 CFR 211.182 - Equipment cleaning and use log.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 4 2010-04-01 2010-04-01 false Equipment cleaning and use log. 211.182 Section... Reports § 211.182 Equipment cleaning and use log. A written record of major equipment cleaning... individual equipment logs that show the date, time, product, and lot number of each batch processed....

  7. Sedimentological analysis using geophysical well logs

    SciTech Connect

    Izotova, T.S. )

    1993-09-01

    The application of geophysical well logs in sedimentology and stratigraphic prospecting holds great promise in solving a number of geological problems. A suite of logs provides data on a wide range of rock properties: vertical and lateral variation of resistivity, natural polarization, natural and induced radioactivity, shear strength, and acoustic properties. Each of these properties is controlled by the depositional environment of the sediments and their later diagenesis. The attention of geologists and geophysicists is drawn to new techniques in the interpretation of geophysical well logs for exploration, appraisal, and development of oil and gas fields. The relationship between geophysical logs and depositional environments is explored. Bulk composition, rock structure, and texture and facies variation can be quantified by electric log parameters. Also, the possibility of using logs to demonstrate long- and short-period sedimentary cycles is demonstrated. Methods of sedimentological analysis using geophysical well logs are demonstrated. The importance of a genetic approach in the interpretation of geological sequences and paleogeological reconstructions is emphasized using examples taken from oil and gas prospecting operations in the Ukraine.

  8. Computer analysis of digital well logs

    USGS Publications Warehouse

    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.

  9. Unconventional neutron sources for oil well logging

    NASA Astrophysics Data System (ADS)

    Frankle, C. M.; Dale, G. E.

    2013-09-01

    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 (252Cf) 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 252Cf, D-D, D-T, filtered D-T, and T-T sources.

  10. Well log characterization of natural gas hydrates

    USGS Publications Warehouse

    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

  11. Well log evaluation of gas hydrate saturations

    USGS Publications Warehouse

    Collett, T.S.

    1998-01-01

    The amount of gas sequestered in gas hydrates is probably enormous, but estimates are highly speculative due to the lack of previous quantitative studies. Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters; one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this study was to develop quantitative well-log evaluation techniques which will permit the calculation of gas-hydrate saturations in gas-hydrate-bearing sedimentary units. The "standard" and "quick look" Archie relations (resistivity log data) yielded accurate gas-hydrate and free-gas saturations within all of the gas hydrate accumulations assessed in the field verification phase of the study. Compressional wave acoustic log data have been used along with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate accurate gas-hydrate saturations in all of the gas hydrate accumulations assessed in this study. The well log derived gas-hydrate saturations calculated in the field verification phase of this study, which range from as low as 2% to as high as 97%, confirm that gas hydrates represent a potentially important source of natural gas.

  12. Well log evaluation of gas hydrate saturations

    USGS Publications Warehouse

    Collett, Timothy S.

    1998-01-01

    The amount of gas sequestered in gas hydrates is probably enormous, but estimates are highly speculative due to the lack of previous quantitative studies. Gas volumes that may be attributed to a gas hydrate accumulation within a given geologic setting are dependent on a number of reservoir parameters; one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well logging devices. The primary objective of this study was to develop quantitative well-log evaluation techniques which will permit the calculation of gas-hydrate saturations in gas-hydrate-bearing sedimentary units. The `standard' and `quick look' Archie relations (resistivity log data) yielded accurate gas-hydrate and free-gas saturations within all of the gas hydrate accumulations assessed in the field verification phase of the study. Compressional wave acoustic log data have been used along with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate accurate gas-hydrate saturations in this study. The well log derived gas-hydrate saturations calculated in the field verification phase of this study, which range from as low as 2% to as high as 97%, confirm that gas hydrates represent a potentially important source of natural gas.

  13. Selecting Aquifer Wells for Planned Gyroscopic Logging

    SciTech Connect

    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

  14. Predicting reservoir wettability via well logs

    NASA Astrophysics Data System (ADS)

    Feng, Cheng; Fu, Jinhua; Shi, Yujiang; Li, Gaoren; Mao, Zhiqiang

    2016-06-01

    Wettability is an important factor in controlling the distribution of oil and water. However, its evaluation has so far been a difficult problem because no log data can directly indicate it. In this paper, a new method is proposed for quantitatively predicting reservoir wettability via well log analysis. Specifically, based on the J function, diagenetic facies classification and the piecewise power functions, capillary pressure curves are constructed from conventional logs and a nuclear magnetic resonance (NMR) log respectively. Under the influence of wettability, the latter is distorted while the former remains unaffected. Therefore, the ratio of the median radius obtained from the two kinds of capillary pressure curve is calculated to reflect wettability, a quantitative relationship between the ratio and reservoir wettability is then established. According to the low-permeability core sample capillary pressure curve, NMR {{T}2} spectrum and contact angle experimental data from the bottom of the Upper Triassic reservoirs in western Ordos Basin, China, two kinds of constructing capillary pressure curve models and a predictive wettability model are calibrated. The wettability model is verified through the Amott wettability index and saturation exponent from resistivity measurement and their determined wettability levels are comparable, indicating that the proposed model is quite reliable. In addition, the model’s good application effect is exhibited in the field study. Thus, the quantitatively predicting reservoir wettability model proposed in this paper provides an effective tool for formation evaluation, field development and the improvement of oil recovery.

  15. Well log evaluation of natural gas hydrates

    SciTech Connect

    Collett, T.S.

    1992-10-01

    Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question linking gas hydrate resource and hazard issues is: What is the volume of gas hydrates and included gas within a given gas hydrate occurrence? Most published gas hydrate resource estimates have, of necessity, been made by broad extrapolation of only general knowledge of local geologic conditions. Gas volumes that may be attributed to gas hydrates are dependent on a number of reservoir parameters, including the areal extent ofthe gas-hydrate occurrence, reservoir thickness, hydrate number, reservoir porosity, and the degree of gas-hydrate saturation. Two of the most difficult reservoir parameters to determine are porosity and degreeof gas hydrate saturation. Well logs often serve as a source of porosity and hydrocarbon saturation data; however, well-log calculations within gas-hydrate-bearing intervals are subject to error. The primary reason for this difficulty is the lack of quantitative laboratory and field studies. The primary purpose of this paper is to review the response of well logs to the presence of gas hydrates.

  16. Well log evaluation of natural gas hydrates

    SciTech Connect

    Collett, T.S.

    1992-10-01

    Gas hydrates are crystalline substances composed of water and gas, in which a solid-water-lattice accommodates gas molecules in a cage-like structure. Gas hydrates are globally widespread in permafrost regions and beneath the sea in sediment of outer continental margins. While methane, propane, and other gases can be included in the clathrate structure, methane hydrates appear to be the most common in nature. The amount of methane sequestered in gas hydrates is probably enormous, but estimates are speculative and range over three orders of magnitude from about 100,000 to 270,000,000 trillion cubic feet. The amount of gas in the hydrate reservoirs of the world greedy exceeds the volume of known conventional gas reserves. Gas hydrates also represent a significant drilling and production hazard. A fundamental question linking gas hydrate resource and hazard issues is: What is the volume of gas hydrates and included gas within a given gas hydrate occurrence Most published gas hydrate resource estimates have, of necessity, been made by broad extrapolation of only general knowledge of local geologic conditions. Gas volumes that may be attributed to gas hydrates are dependent on a number of reservoir parameters, including the areal extent ofthe gas-hydrate occurrence, reservoir thickness, hydrate number, reservoir porosity, and the degree of gas-hydrate saturation. Two of the most difficult reservoir parameters to determine are porosity and degreeof gas hydrate saturation. Well logs often serve as a source of porosity and hydrocarbon saturation data; however, well-log calculations within gas-hydrate-bearing intervals are subject to error. The primary reason for this difficulty is the lack of quantitative laboratory and field studies. The primary purpose of this paper is to review the response of well logs to the presence of gas hydrates.

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

    SciTech Connect

    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.

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

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 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...

  19. 21 CFR 211.182 - Equipment cleaning and use log.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 4 2014-04-01 2014-04-01 false Equipment cleaning and use log. 211.182 Section 211.182 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Records...

  20. 21 CFR 211.182 - Equipment cleaning and use log.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 4 2013-04-01 2013-04-01 false Equipment cleaning and use log. 211.182 Section 211.182 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Records...

  1. 21 CFR 211.182 - Equipment cleaning and use log.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 4 2012-04-01 2012-04-01 false Equipment cleaning and use log. 211.182 Section 211.182 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Records...

  2. 21 CFR 211.182 - Equipment cleaning and use log.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 4 2011-04-01 2011-04-01 false Equipment cleaning and use log. 211.182 Section 211.182 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) DRUGS: GENERAL CURRENT GOOD MANUFACTURING PRACTICE FOR FINISHED PHARMACEUTICALS Records...

  3. Temperature logs of wells and test wells in the Yuma area, Arizona and California

    USGS Publications Warehouse

    Olmsted, F.H.

    1980-01-01

    This report consists of 310 temperature logs made in 266 wells and test wells in the Yuma area, Arizona and California during 1963-69. The work was done as part of a geohydrologic study, the results of which are reported in the 1973 U.S. Geological Survey Professional Paper 486-H; Geohydrology of the Yuma Area, Arizona and California, by Olmsted, Loeltz, and Irelan. Most of the logs are plotted from temperatures measured with two Whitney thermistors at depth intervals of 2 to 20 feet in downward succession in each well or test hole, using land surface as datum. A few logs were made with a truck-mounted wireline logger using thermistor probes and continuously recording equipment. All measurements were in degrees Fahrenheit, later converted to degrees Celsius, and were calibrated with a mercury-in-glass thermometer. Accuracy of most of the measurements was + or - 1.0F and precision was about + or - 0.2F. (USGS)

  4. Geophysical well logging operations and log analysis in Geothermal Well Desert Peak No. B-23-1

    SciTech Connect

    Sethi, D.K.; Fertl, W.H.

    1980-03-01

    Geothermal Well Desert Peak No. B-23-1 was logged by Dresser Atlas during April/May 1979 to a total depth of 2939 m (9642 ft). A temperature of 209/sup 0/C (408/sup 0/F) was observed on the maximum thermometer run with one of the logging tools. Borehole tools rated to a maximum temperature of 204.4/sup 0/C (400/sup 0/F) were utilized for logging except for the Densilog tool, which was from the other set of borehole instruments, rated to a still higher temperature, i.e., 260/sup 0/C (500/sup 0/F). The quality of the logs recorded and the environmental effects on the log response have been considered. The log response in the unusual lithologies of igneous and metamorphic formations encountered in this well could be correlated with the drill cutting data. An empirical, statistical log interpretation approach has made it possible to obtain meaningful information on the rocks penetrated. Various crossplots/histograms of the corrected log data have been generated on the computer. These are found to provide good resolution between the lithological units in the rock sequence. The crossplotting techniques and the statistical approach were combined with the drill cutting descriptions in order to arrive at the lithological characteristics. The results of log analysis and recommendations for logging of future wells have been included.

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

    SciTech Connect

    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.

  6. Fluid-temperature logs for selected wells in eastern Washington

    SciTech Connect

    Stoffel, K.L.; Widness, S.

    1983-12-01

    This Open-File Report consists of fluid temperature logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The fluid temperature logs are divided into two groups. Part A consists of wells which are concentrated in the Moses Lake-Ritzville-Connell area. Full geophysical log suites for many of these wells are presented in Stoffel and Widness (1983) and discussed in Widness (1983, 1984). Part B consists of wells outside of the Moses Lake-Ritzville-Connell study area.

  7. Geophysical logs of selected wells in Eastern Washington

    SciTech Connect

    Stoffel, K.L.; Widness, S.

    1983-12-01

    This report consists of geophysical well logs compiled during studies of the geohydrology and low temperature geothermal resources of eastern Washington. The geophysical logs are divided into two groups. Part A consists of wells concentrated in the Moses Lake-Ritzville-Connell area. Results of the geohydrologic study are discussed in Widness (1983, 1984). Part B consists of wells outside of the Moses Lake-Ritzville-Connell study area.

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

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  11. Improved production log interpretation in horizontal wells using pulsed neutron logs

    SciTech Connect

    Brady, J.L.; Kohring, J.J.; North, R.J.

    1996-12-31

    Production log flow profiles provide a valuable tool to evaluate well and reservoir performance. Horizontal wellbores and their associated completion designs present several challenges to profile interpretation for conventional production logging sensors and techniques. A unique approach combining pulsed neutron capture (PNC) log data with conventional production logging measurements is providing improved flow profile answers in slotted liner, horizontal well completions on the North Slope of Alaska. Identifying and eliminating undesirable gas production is one of the chief goals of production logging on the North Slope. This process becomes difficult in horizontal wellbores as fluid segregation affects the area investigated by the various logging sensors and also the velocities of the individual phases. Typical slotted liner completions further complicate analysis as fluids are able to flow in the liner/openhole annulus. Analysis of PNC log data provides two good qualitative indicators of formation permeability. The first technique is derived from the difference of the formation sigma response before and after injecting a high-capture cross-section borax solution. The second technique uses the difference of the formation sigma response and the formation porosity measured while injecting the formation with crude or seawater. Further analysis of PNC log runs show that the two techniques closely correlate with production flow profiles under solution gas-oil ratio (GOR) conditions. These two techniques in combination with conventional production logging measurements of temperature, capacitance, pressure, and spinner improve flow profile results. PNC results can be combined with temperature and pressure data in the absence of valid spinner data to provide an approximate flow profile. These techniques have been used to successfully determine profiles in both cemented and slotted liner completions with GORs in excess of 15,000 scf/bbl.

  12. 36 CFR 1254.12 - Will NARA log or inspect my computer, other equipment, and notes?

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 36 Parks, Forests, and Public Property 3 2010-07-01 2010-07-01 false Will NARA log or inspect my... MATERIALS General Information § 1254.12 Will NARA log or inspect my computer, other equipment, and notes? (a... Log at the guard's desk. The guard checks the log for proof of your personal ownership before...

  13. Interlake production established using quantitative hydrocarbon well-log analysis

    SciTech Connect

    Lancaster, J.; Atkinson, A.

    1988-07-01

    Production was established in a new pay zone of the basal Interlake Formation adjacent to production in Midway field in Williams County, North Dakota. Hydrocarbon saturation, which was computed using hydrocarbon well-log (mud-log) data, and computed permeability encouraged the operator to run casing and test this zone. By use of drilling rig parameters, drilling mud properties, hydrocarbon-show data from the mud log, drilled rock and porosity descriptions, and wireline log porosity, this new technique computes oil saturation (percent of porosity) and permeability to the invading filtrate, using the Darcy equation. The Leonardo Fee well was drilled to test the Devonian Duperow, the Silurian upper Interlake, and the Ordovician Red River. The upper two objectives were penetrated downdip from Midway production and there were no hydrocarbon shows. It was determined that the Red River was tight, based on sample examination by well site personnel. The basal Interlake, however, liberated hydrocarbon shows that were analyzed by this new technology. The results of this evaluation accurately predicted this well would be a commercial success when placed in production. Where geophysical log analysis might be questionable, this new evaluation technique may provide answers to anticipated oil saturation and producibility. The encouraging results of hydrocarbon saturation and permeability, produced by this technique, may be largely responsible for the well being in production today.

  14. User's manual for geophysical well-logging software programs

    SciTech Connect

    Petrie, G.M.; Gibson, D.; Blair, S.C.

    1983-02-01

    Since 1958 the Ground-Water Surveillance Program for the Hanford Site has made geophysical logging measurements in most of the 800 wells and deep boreholes that have been drilled on the Hanford Site. In 1980 the Pacific Northwest Laboratory (PNL), which conducts the Ground-Water Surveillance Program, began forming a computerized data base for storing and retrieving geophysical well log data and developing software for quantitative analysis of the well log data. This report, designed to serve as a user's guide, documents the data base system that handles the well log data. Two programs, DIGLOG1 and LOGIT, are used to manipulate the data. The program DIGLOG1 translates analog paper strip charts into digital format; the program LOGIT is a general utility program that edits, displays, checks, stores, writes, and deletes sets of well log data. These two programs do not provide sophisticated display and analytical capabilities; rather, they provide programs that give the user easy access to powerful standard analytical software.

  15. Application of the spread-spectrum technique in well logging

    SciTech Connect

    Chrysikopoulos, Constantinos V.; Dadakarides, Simos D.

    1988-01-01

    This paper presents the novel concept of employing the noise insensitive spread-spectrum technique in well logging. The proposed design of a spread-spectrum device improves the performance of well logging tools, particularly within highly noisy environments. The heart of the device is a shift register which generates a pseudorandom binary code sequence. A coder is connected to the transmitter and codes the probing signal by utilizing the pseudorandom sequence. A decoder is connected to the receiver and correlates the return signal to the same sequence, which is used as a sliding reference. Shifts as small as a fraction of a bit are unambiguously resolvable, and distance resolution of the order of micrometers is achievable. Spread-spectrum well logging tools can operate even with coded signal-to-noise ratio below zero-dB. The spread-spectrum device can be interfaced with any available wave transmitting logging tool. However, tools employing acoustic waves are favorable because the acoustic wave propagation velocity is low and allows the use of inexpensive electronics. The problems associated with high temperatures which are commonly encountered In geothermal reservoirs are bypassed, since the spread-spectrum device can be located either inside the well logging tool or together with the supporting electronics on the surface.

  16. A rule-based system for well log correlation

    SciTech Connect

    Startzman, R.A.; Kuo, T.B.

    1987-09-01

    Computer-assisted approaches to well log correlation are of interest to engineers and geologists for two reasons. In large field studies, a computer can be used simply to reduce the time required to correlate zones of interest. It is also possible that computer-assisted correlations may suggest zonal matches of interest and originality that might not have been considered. This paper presents a new approach to the computer-assisted log correlation. Geologic horizons are correlated between wells by use of an artificial intelligence rule-based technique. Using the symbol-manipulation capabilities of a computer language called List Processing (LISP), the author developed a prototype rule-bases system that has symbolic representation of log data, recognizes log shapes from traces, identifies geologic zones from a sequence of shapes in a log, characterizes the zones, correlates zones from well to well with a set of ''if/then'' type of rules, and uses a forward-chaining inference scheme to execute the rule base. The purpose of this paper is to describe the use of the LISP language and the methodology involved in the development of this system.

  17. Electronic neutron sources for compensated porosity well logging

    SciTech Connect

    Chen, Allan Xi; Antolak, Arlyn J; Leung, Ka-Ngo

    2012-02-01

    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.

  18. Electronic neutron sources for compensated porosity well logging

    NASA Astrophysics Data System (ADS)

    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.

  19. Well log characterization of natural gas-hydrates

    USGS Publications Warehouse

    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

  20. Proposed geologic model based on geophysical well logs

    SciTech Connect

    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.

  1. Interpretation of well logs in a carbonate aquifer

    USGS Publications Warehouse

    MacCary, L.M.

    1978-01-01

    data from resistivity logs, the formation water quality can be estimated, as well as the relative cementation or tortuosity of the rock. Many of these properties calculated from logs can be verified by analysis of the core available from test holes drilled in the saline and fresh water zones.

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

    SciTech Connect

    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.

  3. Nuclear Well Log Properties of Natural Gas Hydrate Reservoirs

    NASA Astrophysics Data System (ADS)

    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

  4. Reference manual for data base on Nevada well logs

    USGS Publications Warehouse

    Bauer, E.M.; Cartier, K.D.

    1995-01-01

    The U.S. Geological Survey and Nevada Division of Water Resources are cooperatively using a data base for are cooperatively using a data base for managing well-log information for the State of Nevada. The Well-Log Data Base is part of an integrated system of computer data bases using the Ingres Relational Data-Base Management System, which allows efficient storage and access to water information from the State Engineer's office. The data base contains a main table, two ancillary tables, and nine lookup tables, as well as a menu-driven system for entering, updating, and reporting on the data. This reference guide outlines the general functions of the system and provides a brief description of data tables and data-entry screens.

  5. Drilling, logging and preliminary well testing of geothermal well Susan 1, Susanville, Lassen County, California

    SciTech Connect

    McNitt, J.R.; Petersen, C.A.; Sanyal, S.K.

    1981-03-01

    Susan 1, a hot water production well, was drilled late in 1980 for the City of Susanville, California, as part of its geothermal space-heating project. A history of drilling, logging, completion and pump testing of this well is presented. Susan 1 was drilled to 930 feet using local river water with a 17-1/2-inch bit from 50 to 540 feet and a 12-1/2-inch bit from 540 to 927 feet. A 12-3/4-inch solid casing was set from surface to 350 feet, a slotted casing from 350 to 538 feet, and a 8-5/8-inch slotted casing from 520 to 925 feet. Interpretations of the following logs and test data from this well are presented: drilling logs (penetration rate, water loss and gain, return temperatures); formation logs (description of well cuttings, caliper, spontaneous potential, electrical resistivity, gamma ray, neutron); production logs (temperature, spinner); and pump test data.

  6. Application of Nuclear Well Logging Techniques to Lunar Resource Assessment

    NASA Technical Reports Server (NTRS)

    Albats, P.; Groves, J.; Schweitzer, J.; Tombrello, T.

    1992-01-01

    The use of neutron and gamma ray measurements for the analysis of material composition has become well established in the last 40 years. Schlumberger has pioneered the use of this technology for logging wells drilled to produce oil and gas, and for this purpose has developed neutron generators that allow measurements to be made in deep (5000 m) boreholes under adverse conditions. We also make ruggedized neutron and gamma ray detector packages that can be used to make reliable measurements on the drill collar of a rotating drill string while the well is being drilled, where the conditions are severe. Modern nuclear methods used in logging measure rock formation parameters like bulk density and porosity, fluid composition, and element abundances by weight including hydrogen concentration. The measurements are made with high precision and accuracy. These devices (well logging sondes) share many of the design criteria required for remote sensing in space; they must be small, light, rugged, and able to perform reliably under adverse conditions. We see a role for the adaptation of this technology to lunar or planetary resource assessment missions.

  7. Scanned well-log image and digital data management

    SciTech Connect

    Zainalabedin, K.A.; Derr, M.E.; Fenn, C.J.

    1995-08-01

    As part of a comprehensive, multidisciplinary data-management project, libraries of computer-archived well logs that provide access to both scanned-image and digitized-curve data are under development. A comprehensive set of retrieval and management tools facilitates log-image and digitized-curve access and use. Images are accessible for viewing on Unix workstation and mainframe terminals at all office locations and also may be plotted as hard-copy paper prints. Network connectivity and file sharing also facilitate transfer to workstation analytical software. By using the central mainframe as a library and catalog manager, mass storage and database-intensive management tasks are handled outside of the Unix networks. Independence from the rapidly developing workstation network environment reduces database maintenance and permits longer-term data management planning than would otherwise be practical. Image libraries are a development step in a trend toward an image-based work environment in which well-log and other geotechnical image data are expected to become primary analytical resources.

  8. Scanned well log image and digital curve management

    SciTech Connect

    Zainalabedin, K.A.; Derr, M.E.; Fenn, C.J.

    1994-12-31

    As part of a comprehensive, multi-disciplinary data management project, libraries of computer archived well logs are under development which provide access to both scanned image and digitized curve data. A comprehensive set of retrieval and management tools facilitate log image and digitized curve access and utilization. Images are accessible for viewing on UNIX workstation and mainframe terminals at all office locations, and may also be plotted as hardcopy paper prints. Network connectivity and file sharing also facilitate transfer to workstation analytical software. By utilizing the central mainframe as a library and catalog manager, mass storage and database-intensive management tasks are handled outside of the UNIX networks. Independence from the rapidly developing workstation network environment reduces database maintenance and permits longer-term data management planning than would otherwise be practical. Image libraries are a developmental step in a trend toward an image-based work environment in which well log and other geo-technical image data are expected to become primary analytical resources.

  9. High voltage supply for neutron tubes in well logging applications

    DOEpatents

    Humphreys, D. Russell

    1989-01-01

    A high voltage supply is provided for a neutron tube used in well logging. The "biased pulse" supply of the invention combines DC and "full pulse" techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

  10. 36 CFR 1254.12 - Will NARA log or inspect my computer, other equipment, and notes?

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... computer, other equipment, and notes? 1254.12 Section 1254.12 Parks, Forests, and Public Property NATIONAL... MATERIALS General Information § 1254.12 Will NARA log or inspect my computer, other equipment, and notes? (a) If you bring personal computers, scanners, tape recorders, cameras, and other equipment into...

  11. 36 CFR 1254.12 - Will NARA log or inspect my computer, other equipment, and notes?

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... computer, other equipment, and notes? 1254.12 Section 1254.12 Parks, Forests, and Public Property NATIONAL... MATERIALS General Information § 1254.12 Will NARA log or inspect my computer, other equipment, and notes? (a) If you bring personal computers, scanners, tape recorders, cameras, and other equipment into...

  12. 36 CFR 1254.12 - Will NARA log or inspect my computer, other equipment, and notes?

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... computer, other equipment, and notes? 1254.12 Section 1254.12 Parks, Forests, and Public Property NATIONAL... MATERIALS General Information § 1254.12 Will NARA log or inspect my computer, other equipment, and notes? (a) If you bring personal computers, scanners, tape recorders, cameras, and other equipment into...

  13. 36 CFR 1254.12 - Will NARA log or inspect my computer, other equipment, and notes?

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... computer, other equipment, and notes? 1254.12 Section 1254.12 Parks, Forests, and Public Property NATIONAL... MATERIALS General Information § 1254.12 Will NARA log or inspect my computer, other equipment, and notes? (a) If you bring personal computers, scanners, tape recorders, cameras, and other equipment into...

  14. Hydrocarbon segregation from well logs, Northern Monagas, Venezuela

    SciTech Connect

    Garcia, E. )

    1993-02-01

    A methodology is described to determine vertical hydrocarbon density variations in recent oil discoveries in Northern Monagas state, using well logs. Similarities and differences are established for models obtained in El Carito and El Tejero fault block-s. These models were confirmed using independent information, such as PVT analysis, RFT pressures, oil gravity and GOR's from initial production tests. To explain differences between the models, an hypothesis is proposed for the migration/segregation/deformation sequence in these two blocks, which accounts for the presence of lighter hydrocarbons in El Tejero block, even though it is 1700 ft structurally lower than El Carito. Based on this hypothesis, westward projection of the models predicts lighter hydrocarbons and similar porosities for Casupal-Mata Granda and Tonoro blocks, at depths considerably greater than in El Tejero block.

  15. Color images of Kansas subsurface geology from well logs

    USGS Publications Warehouse

    Collins, D.R.; Doveton, J.H.

    1986-01-01

    Modern wireline log combinations give highly diagnostic information that goes beyond the basic shale content, pore volume, and fluid saturation of older logs. Pattern recognition of geology from logs is made conventionally through either the examination of log overlays or log crossplots. Both methods can be combined through the use of color as a medium of information by setting the three color primaries of blue, green, and red light as axes of three dimensional color space. Multiple log readings of zones are rendered as composite color mixtures which, when plotted sequentially with depth, show lithological successions in a striking manner. The method is extremely simple to program and display on a color monitor. Illustrative examples are described from the Kansas subsurface. ?? 1986.

  16. Hydraulic parameters estimation from well logging resistivity and geoelectrical measurements

    NASA Astrophysics Data System (ADS)

    Perdomo, S.; Ainchil, J. E.; Kruse, E.

    2014-06-01

    In this paper, a methodology is suggested for deriving hydraulic parameters, such as hydraulic conductivity or transmissivity combining classical hydrogeological data with geophysical measurements. Estimates values of transmissivity and conductivity, with this approach, can reduce uncertainties in numerical model calibration and improve data coverage, reducing time and cost of a hydrogeological investigation at a regional scale. The conventional estimation of hydrogeological parameters needs to be done by analyzing wells data or laboratory measurements. Furthermore, to make a regional survey many wells should be considered, and the location of each one plays an important role in the interpretation stage. For this reason, the use of geoelectrical methods arises as an effective complementary technique, especially in developing countries where it is necessary to optimize resources. By combining hydraulic parameters from pumping tests and electrical resistivity from well logging profiles, it was possible to adjust three empirical laws in a semi-confined alluvial aquifer in the northeast of the province of Buenos Aires (Argentina). These relations were also tested to be used with surficial geoelectrical data. The hydraulic conductivity and transmissivity estimated in porous material were according to expected values for the region (20 m/day; 457 m2/day), and are very consistent with previous results from other authors (25 m/day and 500 m2/day). The methodology described could be used with similar data sets and applied to other areas with similar hydrogeological conditions.

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

    SciTech Connect

    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.

  18. Symposium on high-temperature well-logging instrumentation

    SciTech Connect

    Dennis, B.R.

    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)

  19. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... I hazardous waste injection well, appropriate logs and tests shall be run to determine or verify the... interpreting results of such logs and tests shall be prepared by a knowledgeable log analyst and submitted to the Director. At a minimum, such logs and tests shall include: (1) Deviation checks during drilling...

  20. An index of geophysical well logging in Virginia by the U.S. Geological Survey

    USGS Publications Warehouse

    Mulheren, M. Patrick; Larson, J.D.; Hopkins, Herbert T.

    1982-01-01

    Geophysical logs have been obtained in more than 170 wells in Virginia by the U.S. Geological Survey since 1968. These logs include natural gamma, electric, caliper, temperature, fluid conductivity, and fluid velocity. Most of the logs are for wells in the Coastal Plain Province of eastern Virginia. Geophysical logs aid in the interpretation of properties of earth materials, including the capacity to store and transmit water in the immediate vicinity of the well bore.

  1. Case history on geothermal-well-log interpretation: Surprise Valley, California

    SciTech Connect

    Rigby, F.A.; Zebal, G.P.

    1981-06-01

    Well logs from a 1972 geothermal well drilled in California's Surprise Valley are discussed. The well is in an igneous formation, primarily basalt in the logged interval, and had a bottom-hole temperature of about 170/sup 0/C at a total depth exceeding 1400 m. It produced good flow rates from what is presumably a formation with predominately fracture-related permeability. The well has special interest because fractures could be located approximately by the appearance of well-defined secondary crystallization in the drill cuttings. The original use of the log data in evaluating the well when it was drilled is discussed. In addition, the log data are reviewed and valuable data are obtained on log response in basalts, the effects of secondary mineralization, fracture detection, and aspects of the resistivity logs. The Surprise Valley well gives a clear demonstration of the value of thorough logging in geothermal exploratory wells, especially in the identification and location of potential production zones.

  2. Downhole well log and core montages from the Mount Elbert Gas Hydrate Stratigraphic Test Well, Alaska North Slope

    USGS Publications Warehouse

    Collett, T.S.; Lewis, R.E.; Winters, W.J.; Lee, M.W.; Rose, K.K.; Boswell, R.M.

    2011-01-01

    The BPXA-DOE-USGS Mount Elbert Gas Hydrate Stratigraphic Test Well was an integral part of an ongoing project to determine the future energy resource potential of gas hydrates on the Alaska North Slope. As part of this effort, the Mount Elbert well included an advanced downhole geophysical logging program. Because gas hydrate is unstable at ground surface pressure and temperature conditions, a major emphasis was placed on the downhole-logging program to determine the occurrence of gas hydrates and the in-situ physical properties of the sediments. In support of this effort, well-log and core data montages have been compiled which include downhole log and core-data obtained from the gas-hydrate-bearing sedimentary section in the Mount Elbert well. Also shown are numerous reservoir parameters, including gas-hydrate saturation and sediment porosity log traces calculated from available downhole well log and core data. ?? 2010.

  3. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable... Class I hazardous waste injection wells: (1) Fracture pressure; (2) Other physical and...

  4. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable... Class I hazardous waste injection wells: (1) Fracture pressure; (2) Other physical and...

  5. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable... Class I hazardous waste injection wells: (1) Fracture pressure; (2) Other physical and...

  6. 40 CFR 146.66 - Logging, sampling, and testing prior to new well operation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... cement bond and variable density log, and a temperature log after the casing is set and cemented. (ii..., gamma ray, and fracture finder logs before the casing is installed; and (B) A cement bond and variable... Class I hazardous waste injection wells: (1) Fracture pressure; (2) Other physical and...

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

    PubMed

    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.

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

    USGS Publications Warehouse

    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.

  9. Drilling, construction, and caliper-log data for wells 3-3204-01, Kaheaka exploratory well, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The Kaheaka exploratory well (State well number 3-3204-01) was drilled about 3.3 miles southeast of the town of Haleiwa. The well is on agricultural land in the Waialua ground-water area. The well penetrates about 67 feet into a basalt aquifer. Well-construction data, logs of drilling notes, geologic descriptions for the samples, and caliper-log data are presented for the well. The well is one of 12 exploratory wells drilled in the north-central Oahu area between July 1993 and May 1994 in cooperation with the Honolulu Board of Water Supply.

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

    SciTech Connect

    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.

  11. Flowing fluid electric conductivity logging for a deep artesian well in fractured rock with regional flow

    NASA Astrophysics Data System (ADS)

    Doughty, Christine; Tsang, Chin-Fu; Yabuuchi, Satoshi; Kunimaru, Takanori

    2013-03-01

    SummaryThe flowing fluid electric conductivity (FFEC) logging method is a well-logging technique that may be used to estimate flow rate, salinity, transmissivity, and hydraulic head of individual fractures or high-permeability zones intersected by a wellbore. Wellbore fluid is first replaced with fluid of a contrasting electric conductivity, then repeated FEC logging is done while the well is pumped. Zones where fluid flows into the wellbore show peaks in the FEC logs, which may be analyzed to infer inflow rate and salinity of the individual fractures. Conducting the procedure with two or more pumping rates (multi-rate FFEC logging) enables individual fracture transmissivity and hydraulic head to be determined. Here we describe the first application of the multi-rate FFEC logging method to an artesian well, using a 500-m well in fractured rock at Horonobe, Japan. An additional new factor at the site is the presence of regional groundwater flow, which heretofore has only been studied with synthetic data. FFEC logging was conducted for two different pumping rates. Several analysis techniques had to be adapted to account for the artesian nature of the well. The results were subsequently compared with independent salinity measurements and transmissivity and hydraulic head values obtained from packer tests in the same well. Despite non-ideal operating conditions, multi-rate FFEC logging successfully determined flow rate, salinity, and transmissivity of 17 conducting fractures intercepted by the logged section of the borehole, including two fractures with regional groundwater flow. Predictions of hydraulic head were less accurate, a not unexpected result in light of operational problems and the form of the equation for hydraulic head, which involves the difference between two uncertain quantities. This study illustrates the strengths and weaknesses of the multi-rate FFEC logging method applied to artesian wells. In conjunction with previous studies, it demonstrates the

  12. Course An Introduction to Geothermal Resources - Well Completion Production Equipment

    SciTech Connect

    Ascuaga, John; Garrett, B.D.

    1987-10-01

    A course to introduce geothermal energy held in Sparks, Nevada on October 1987. Topics included well draining and well computation production equipment. There is much technical detail and some cost detail. [DJE-2005

  13. 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

    USGS Publications Warehouse

    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.

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

    SciTech Connect

    Adams, A.; Dennis, B.; Van Eeckhout, E.; Goff, F.; Lawton, R.; Trujillo, P.E.; Counce, D.; Archuleta, J. ); Medina, V. . 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.

  15. Study of well logs from Cove Fort-Sulphurdale KGRA, Millard and Beaver Counties, Utah

    SciTech Connect

    Glenn, W.E.; Ross, H.P.

    1982-07-01

    Union Oil Company drilled four geothermal test wells in the Cove Fort-Sulphurdale KGRA between 1975 and 1979. A fairly complete suite of well logs were recorded for the three deeper holes, and these data are presented as composite well log plots in this report. The composite well log plots have facilitated the interpretation of limestone, dolomite, sandstone, quartz-monzonite, serpentine, and volcanic lithologies and the identification of numerous fractures. This has been especially helpful because of the extensive lost circulaton zones and poor cuttings recovery. Intraformational flow was identified by a fluid migration-temperature tracer log at depth in CFSU 31-33. Well log crossplots were computed to assist in lithologic identification and the determination of physical properties for specific depth intervals in a given hole. The presence of hydrous minerals sometimes results in neutron porosity somewhat higher than the true nonfracture porosity, which is generally less than 4%. Permeability is clearly controlled by fractures. A maximum well temperature of 178.9/sup 0/C, low flow rates and low probable percent flash indicate these wells are subeconomic for electric generation at present. The well log study has substantially improved our understanding of the reservoir as presently drilled.

  16. A new method for investigating heterogeneities from well logs using the Hilbert-Huang transform

    NASA Astrophysics Data System (ADS)

    Gaci, Said; Zaourar, Naima; Hachay, Olga

    2015-04-01

    Borehole logs exhibit multi-scale properties that cannot be analyzed using the conventional tools. Here, we propose a new method based on Hilbert-Huang transform (HHT), a combination of the empirical mode decomposition (EMD) and Hilbert transform (HT), for estimating a local scaling coefficient from well logs. This parameter measures heterogeneities degree of the layers crossed by the borehole. The proposed technique has been applied on P- and S-wave seismic velocity logs recorded at the KTB main borehole drilled for the German Continental Deep Drilling program. The calculated depth-dependent scaling parameter highlighted the lithological discontinuities occurred within the logged depth interval, and allowed to measure the complexity of underground heterogeneities. To conclude, the suggested method presents a new way to explore multi-scale features of the logs data, and may bring additional information to the conventional analysis tools. More datasets are needed to establish a possible relationship between the local scaling parameter and lithology.

  17. Well construction, lithology, and geophysical logs for boreholes in Bear Creek Valley near Oak Ridge, Tennessee

    USGS Publications Warehouse

    Bailey, Z.C.; Hanchar, D.W.

    1988-01-01

    Twenty-four wells were constructed at nine sites at Bear Creek Valley to provide geologic and hydrologic information. Lithologic samples and suits of geophysical logs were obtained from the deepest boreholes at six of the sites. Two of these boreholes at the base of Chestnut Ridge were completed in the Maynardville Limestone and two were completed in the Nolichucky Shale. Two boreholes along Pine Ridge were completed in the Rome Formation. Zones of similar lithology within a borehole were delineated from rock cutting refined by examination of geophysical logs. The contact between the Maynardville Limestone and Nolichucky Shale was identified in two of the boreholes. Fractures and cavities were readily identifiable on the acoustic-televiewer and caliper logs. Distinct water-bearing intervals were also identified from the temperature, fluid resistance, and resistivity logs. Depths at which the drilling encounterd a thrust were identified in two boreholes in the Rome Formation from both rock cutting and geophysical logs. (USGS)

  18. Results of well logging operations at the Ahuachapan geothermal field, El Salvador

    SciTech Connect

    Dennis, B.; Jermance, R.; Lawton, R.; Quintinilla, A.; Berganza, J.

    1988-01-01

    Well logging operations were performed in eight of the geothermal wells at Ahucachapan. A series of high temperature instruments, including temperature/rabbit, caliper, fluid velocity/temperature/pressure (STP) and fluid sampler were deployed in each well. The caliper tool was used primarily to determine the possible chemical desposit buildup in the casing or liner, and in one well to investigate a suspected break in the casing. STP logs were obtained from six of the eight wells at various flow rates ranging from 30 to 70 kg/s. A static STP log was also run with the wells shut in to provide data to be used in the thermodynamic analysis of several production wells. 23 refs., 1 tab.

  19. Lithology determination from digitized well logs - examples from Ore-Ida No. 1 geothermal well, Ontario, Oregon

    SciTech Connect

    Sanyal, S.K.; Glenn, W.E.

    1981-10-01

    Some of the advantages and pitfalls of lithology determination from digitized well logs are presented. Examples are provided from the Ore-Ida No. 1 geothermal well in Ontario, Oregon, drilled through a sequence of siltstone, clay, tuff and basalt/andesite. The use of histograms and crossplots to differentiate various lithological units and to identify alteration is illustrated.

  20. Drilling, construction, and caliper-log data for well 3-3505-25, North Lower Anahulu exploratory well, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The North Lower Anahulu exploratory well (State well number 3-3505-25) was drilled about 1.4 miles east-northeast of the town of Haleiwa. The well was drilled on agricultural land in the Kawailoa ground-water area. The well was drilled from an elevation of about 232 feet above mean sea level and penetrates about 22 feet into a basalt aquifer. Well-construction data, logs of drilling notes, geologic descriptions for the samples, and caliper-log data are presented for the well. The well is one of 12 exploratory wells drilled in the north-central Oahu area between July, 1993 and May, 1994 in cooperation with the Honolulu Board of Water Supply.

  1. Drilling, construction, and caliper-log data for well 3-3505-26, Opaeula exploratory well, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The Opaeula exploratory well (State well number 3-3505-26) was drilled about 1.2 miles east- southeast of the town of Haleiwa. The well is located on agricultural land in the Waialua ground-water area. The well was drilled at an elevation of about 287 feet above mean sea level and penetrates about 75 feet into a basalt aquifer. Well-construction data, logs of drilling notes, geologic descriptions for the samples, and caliper-log data are presented for the well. The well is one of 12 exploratory wells drilled in the north-central Oahu area between July 1993 and May 1994 in cooperation with the Honolulu Board of Water Supply.

  2. Compilation of 29 sonic and density logs from 23 oil test wells in western Washington State

    USGS Publications Warehouse

    Brocher, Thomas M.; Ruebel, April L.

    1998-01-01

    Three-dimensional velocity models for Puget Sound provide a means for better understanding the lateral variations in strong ground motions recorded during local earthquakes in Puget Lowland. We have compiled 29 sonic and density logs from 23 oil test wells to help us determine the geometry and physical properties of the Cenozoic basins in western Washington. The maximum depths sampled by the test wells are between 0.47 and 4.04 km. These well logs sample Quaternary to Eocene sedimentary and volcanic rocks. This report presents the locations, elevations, depths, stratigraphic and other information about the test wells, and provides plots showing the density and sonic velocities as a function of depth for each well log. We also present two-way travel times calculated from the sonic velocities.

  3. Investigating uplift in the South-Western Barents Sea using sonic and density well log measurements

    NASA Astrophysics Data System (ADS)

    Yang, Y.; Ellis, M.

    2014-12-01

    Sediments in the Barents Sea have undergone large amounts of uplift due to Plio-Pleistoncene deglaciation as well as Palaeocene-Eocene Atlantic rifting. Uplift affects the reservoir quality, seal capacity and fluid migration. Therefore, it is important to gain reliable uplift estimates in order to evaluate the petroleum prospectivity properly. To this end, a number of quantification methods have been proposed, such as Apatite Fission Track Analysis (AFTA), and integration of seismic surveys with well log data. AFTA usually provides accurate uplift estimates, but the data is limited due to its high cost. While the seismic survey can provide good uplift estimate when well data is available for calibration, the uncertainty can be large in areas where there is little to no well data. We estimated South-Western Barents Sea uplift based on well data from the Norwegian Petroleum Directorate. Primary assumptions include time-irreversible shale compaction trends and a universal normal compaction trend for a specified formation. Sonic and density logs from two Cenozoic shale formation intervals, Kolmule and Kolje, were used for the study. For each formation, we studied logs of all released wells, and established exponential normal compaction trends based on a single well. That well was then deemed the reference well, and relative uplift can be calculated at other well locations based on the offset from the normal compaction trend. We found that the amount of uplift increases along the SW to NE direction, with a maximum difference of 1,447 m from the Kolje FM estimate, and 699 m from the Kolmule FM estimate. The average standard deviation of the estimated uplift is 130 m for the Kolje FM, and 160 m for the Kolmule FM using the density log. While results from density logs and sonic logs have good agreement in general, the density log provides slightly better results in terms of higher consistency and lower standard deviation. Our results agree with published papers

  4. View of McKenzieRichey covered well showing log and lumber construction ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    View of McKenzie-Richey covered well showing log and lumber construction and shingles, facing southeast - McKenzie Property, Covered Well, North Bank of Sailor Gulch, 750 feet northwest of intersection of U.S.F.S. Roads 651 & 349, Placerville, Boise County, ID

  5. Estimating pore-space gas hydrate saturations from well log acoustic data

    USGS Publications Warehouse

    Lee, Myung W.; Waite, William F.

    2008-01-01

    Relating pore-space gas hydrate saturation to sonic velocity data is important for remotely estimating gas hydrate concentration in sediment. In the present study, sonic velocities of gas hydrate–bearing sands are modeled using a three-phase Biot-type theory in which sand, gas hydrate, and pore fluid form three homogeneous, interwoven frameworks. This theory is developed using well log compressional and shear wave velocity data from the Mallik 5L-38 permafrost gas hydrate research well in Canada and applied to well log data from hydrate-bearing sands in the Alaskan permafrost, Gulf of Mexico, and northern Cascadia margin. Velocity-based gas hydrate saturation estimates are in good agreement with Nuclear Magneto Resonance and resistivity log estimates over the complete range of observed gas hydrate saturations.

  6. Methods for estimating petrophysical parameters from well logs in tight oil reservoirs: a case study

    NASA Astrophysics Data System (ADS)

    Zhao, Peiqiang; Zhuang, Wen; Sun, Zhongchun; Wang, Zhenlin; Luo, Xingping; Mao, Zhiqiang; Tong, Zemin

    2016-02-01

    Estimating petrophysical parameters from well logs plays a significant role in the exploration and development of tight oil resources, but faces challenges. What’s more, the methods for petrophysical parameters from well logs are paid little attention at present. In this paper, the typical tight oil reservoirs of Northwest China are used as an example. Based on the characteristics of mineralogy and fluids in the study field, the rock is assumed into five components which are clays, quartz and feldspar, carbonates, kerogen and pore fluids (porosity). The sum of kerogen content and porosity is defined as the apparent porosity. Then, two porosity log response equations are established. Once the clay content is determined by an individual method, the quartz and feldspar content, carbonate content and apparent porosity are calculated through the established equations. The kerogen content is the difference of the apparent porosity and porosity from nuclear magnetic resonance (NMR) logs. This paper also presents a new approach that combines the complex refractive index method (CRIM) and pseudo Archie method to compute saturation from dielectric logs, which avoids selection for the dielectric constants of each of the minerals. The effectiveness and reliability of these methods are verified by the successful application in the study of the target tight oil play in Northwest China.

  7. Seismic- and well-log-inferred gas hydrate accumulations on Richards Island

    USGS Publications Warehouse

    Collett, T.S.

    1999-01-01

    The gas hydrate stability zone is areally extensive beneath most of the Mackenzie Delta-Beaufort Sea region, with the base of the gas hydrate stability zone more than 1000 m deep on Richards Island. In this study, gas hydrate has been inferred to occur in nine Richards Island exploratory wells on the basis of well-log responses calibrated to the response of the logs within the cored gas-hydrate-bearing intervals of the JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well. The integration of the available well-log data with more than 240 km of industry-acquired reflection seismic data have allowed us to map the occurrence of four significant gas hydrate and associated free-gas accumulations in the Ivik-Mallik-Taglu area on Richards Island. The occurrence of gas hydrate on Richards Island is mostly restricted to the crest of large anticlinal features that cut across the base of the gas hydrate stability zone. Combined seismic and well-log data analysis indicate that the known and inferred gas hydrate accumulations on Richards Island may contain as much as 187 178106 m3 of gas.

  8. Geophysical logs for selected wells in the Picher Field, northeast Oklahoma and southeast Kansas

    USGS Publications Warehouse

    Christenson, Scott C.; Thomas, Tom B.; Overton, Myles D.; Goemaat, Robert L.; Havens, John S.

    1991-01-01

    The Roubidoux aquifer in northeastern Oklahoma is used extensively as a source of water for public supplies, commerce, industry, and rural water districts. The Roubidoux aquifer may be subject to contamination from abandoned lead and zinc mines of the Picher field. Water in flooded underground mines contains large concentrations of iron, zinc, cadmium, and lead. The contaminated water may migrate from the mines to the Roubidoux aquifer through abandoned water wells in the Picher field. In late 1984, the Oklahoma Water Resources Board began to locate abandoned wells that might be serving as conduits for the migration of contaminants from the abandoned mines. These wells were cleared of debris and plugged. A total of 66 wells had been located, cleared, and plugged by July 1985. In cooperation with the Oklahoma Water Resources Board, the U.S. Geological Survey took advantage of the opportunity to obtain geophysical data in the study area and provide the Oklahoma Water Resources Board with data that might be useful during the well-plugging operation. Geophysical logs obtained by the U.S. Geological Survey are presented in this report. The geophysical logs include hole diameter, normal, single-point resistance, fluid resistivity, natural-gamma, gamma-gamma, and neutron logs. Depths logged range from 145 to 1,344 feet.

  9. Geophysical well log analysis of fractured granitic rocks at Atikokan, Ontario, Canada

    USGS Publications Warehouse

    Paillet, Frederick L.; Hess, A.E.

    1987-01-01

    Two boreholes, drilled to approximate depths of 750 and 1,260 m in a granitic intrusion located near Atikokan, Ontario, were studied by obtaining a full suite of conventional borehole geophysical logs. In addition, selected intervals in these boreholes were logged with a borehole acoustic televiewer that produces a high-resolution image of the borehole wall, an acoustic waveform-logging system using 34-kiloHertz magnetostrictive and 5-kiloHertz sparker sources, and a highly sensitive heat-pulse flowmeter. Emphasis was on identifying and characterizing fracture zones that represent groundwater conduits in deeper portions of the granite, and on characterizing the properties of the largest intervals of unfractured granite. Major fracture zones were indicated by correlating geophysical log anomalies detected on the suite of conventional logs (unpublished data from Atomic Energy of Canada). However, several other anomalies, were identified as mafic intrusions of approximately the same thickness as major fracture zones. Geophysical log anomalies were compared for all major fracture zones that could serve as significant groundwater conduits, and fracture zone permeability is estimated on the basis of acoustic tube-wave attenuation in these intervals. Acoustic televiewer logs obtained at depths below 1,000 m in the deeper well indicate that most of the few fractures identified on core at these depths do not remain open enough under in situ conditions to produce detectable anomalies in acoustic refraction. Flowmeter data indicate that some groundwater circulation occurs in the upper portion of both boreholes. Water in the shallower of the two holes was observed to flow at 2.0 L/min; most of this flow entered the borehole at a depth < 25 m, and no flow occurred below a depth of 100 m. Downflow at rates < 0.5 L/min was determined to enter the deeper borehole within 20 m of the surface, and to exist at various fractures down to a depth of 250 m. (Author 's abstract)

  10. Log ASCII Standard (LAS) Files for Geophysical Wireline Well Logs and Their Application to Geologic Cross Sections Through the Central Appalachian Basin

    USGS Publications Warehouse

    Crangle, Robert D.

    2007-01-01

    Introduction The U.S. Geological Survey (USGS) uses geophysical wireline well logs for a variety of purposes, including stratigraphic correlation (Hettinger, 2001, Ryder, 2002), petroleum reservoir analyses (Nelson and Bird, 2005), aquifer studies (Balch, 1988), and synthetic seismic profiles (Kulander and Ryder, 2005). Commonly, well logs are easier to visualize, manipulate, and interpret when available in a digital format. In recent geologic cross sections E-E' and D-D', constructed through the central Appalachian basin (Ryder, Swezey, and others, in press; Ryder, Crangle, and others, in press), gamma ray well log traces and lithologic logs were used to correlate key stratigraphic intervals (Fig. 1). The stratigraphy and structure of the cross sections are illustrated through the use of graphical software applications (e.g., Adobe Illustrator). The gamma ray traces were digitized in Neuralog (proprietary software) from paper well logs and converted to a Log ASCII Standard (LAS) format. Once converted, the LAS files were transformed to images through an LAS-reader application (e.g., GeoGraphix Prizm) and then overlain in positions adjacent to well locations, used for stratigraphic control, on each cross section. This report summarizes the procedures used to convert paper logs to a digital LAS format using a third-party software application, Neuralog. Included in this report are LAS files for sixteen wells used in geologic cross section E-E' (Table 1) and thirteen wells used in geologic cross section D-D' (Table 2).

  11. Relevant aspects of radiation protection in oil and gas well logging.

    PubMed

    Gomes, R S; Lopes Gomes, J D R; Costa, M L L; Miranda, M V F E S

    2013-12-01

    Radiation sources have being widely used in industrial applications, but their inappropriate use presents a large potential for hazards to human health and the environment. These hazards can be minimised by development of specific radiation protection rules and adequate procedures for the handling, use and storage of radiation sources, which should be established in a national normative framework. Recently, due to discovery of new oil and gas reservoirs on the Brazilian continental shelf, especially in deep water and the pre-salt layer, there has been a large and rapid increase in the use of radiation sources for well logging. Generic radiation protection regulations have been used for licensing the use of radiation sources for well logging, but these are not comprehensive or technically suitable for this purpose. Therefore it is necessary to establish specific Brazilian safety regulations for this purpose. In this work, an assessment is presented of the relevant radiation protection aspects of nuclear well logging not covered by generic regulations, with the aim of contributing to the future development of specific safety regulations for the licensing of radioactive facilities for oil and gas well logging in Brazil. The conclusions of this work relate to four areas, which include the specific requirements to control (1) radiation sources, (2) radiation survey meters and (3) access to radiation workplaces and (4) to control and identify the workers who are occupationally exposed.

  12. Commercial geophysical well logs from the USW G-1 drill hole, Nevada Test Site, Nevada

    USGS Publications Warehouse

    Muller, D.C.; Kibler, J.E.

    1983-01-01

    Drill hole USW G-1 was drilled at Yucca Mountain, Nevada Test Site, Nevada, as part of the ongoing exploration program for the Nevada Nuclear Waste Storage Investigations. Contract geophysical well logs run at USW G-1 show only limited stratigraphic correlations, but correlate reasonably well with the welding of the ash-flow and ash-fall tuffs. Rocks in the upper part of the section have highly variable physical properties, but are more uniform and predictably lower in the section.

  13. A comparison of CBL, RBT, and PET logs in a test well with induced channels

    SciTech Connect

    Albert, L.E.; Standley, T.E.; Tello, L.N.; Alford, G.T.

    1988-09-01

    The introduction of new ultrasonic and ratio logging techniques has dramatically transformed cement evaluation. Previous methods (cement bond logs (CBL's)) that used a low-frequency (approx. = 20 x 10/sup 3/-recycle/sec (approx. = 20-kHz)) acoustic signal and a single-transmitter/dual-receiver combination suffered from inherent measurement problems. To eliminate several of the CBL problems a new dual-transmitter/multireceiver acoustic measurement tool, the ratio bond tool (RBT), has been introduced. The RBT measures attenuation directly through ratiometric techniques, is self-calibrating, and is much less sensitive to tool centralization. For cement evaluation across ''fast formation'' intervals, a 1-ft (0.33-m) -spaced transmitter/receiver signal amplitude is measured. A ''logging well'' has been constructed by the U.S. Environmental Protection Agency (EPA) to evaluate downhole tool response to cement channels. This test well was constructed with numerous sizes and weights of casings and has specially constructed flaws on the casing circumference to produce channels of variable lengths and widths. A detailed analysis of the ability of the CBL, RBT, and PET logs to detect these channels is presented.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. 75 FR 75995 - Request for Comments on Helium-3 Use in the Oil and Natural Gas Well Logging Industry

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-07

    ... byproduct of the decay of Tritium. Its main use is for neutron detection devices used in scientific research... 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...

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

    SciTech Connect

    Stout, J.; Qualheim, B.; McPherrin, R.; Barber, K.; Hedegaard, R.; McConihe, W.; Miller, T.

    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.

  17. Analysis of well logging methods in volcanic and volcano sedimentary rocks from Pina petroleum field

    SciTech Connect

    Rodriquez, N.

    1996-09-01

    Petrophysical, petrological and geophysical methods have been applied to prospecting and well logging for several petroleum fields in Cuba. The most common reservoir in these fields are carbonate rocks. However, the Pina field, in the Central region of the island, distinguishes itself by the good quality of the oil and the volcano sedimentary and volcanic character of the reservoirs. These rocks have peculiar geophysical responses, which is why the study of these methods and the development of the interpretation methods is very important. Integrated geological and geophysical information was necessary during the drilling of wells in the Pina field in order to evaluate the hydrocarbon potential. GEONUC code permits us to use different ways to solve questions about interpretation of well logging in the volcanic sedimentary rocks. This code gives us the opportunity to analyze complex methods.

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

    USGS Publications Warehouse

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

    2014-01-01

    Maximum groundwater temperatures at the bottom of the logs ranged from 11.2 to 15.4 degrees Celsius. Geothermal gradients were generally higher than those typically reported for other water wells in the United States. Some of the high gradients were associated with high natural gamma emissions. Groundwater flow was discernible in 4 of the 10 wells studied but only obscured the part of the geothermal gradient signal where groundwater actually flowed into, out of, or through the well. Temperature gradients varied by mapped bedrock type but can also vary by localized differences in mineralogy or rock type within the wells.

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

    USGS Publications Warehouse

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

    2012-01-01

    Maximum groundwater temperatures at the bottom of the logs were between 11.7 and 17.3 degrees Celsius. Geothermal gradients were generally higher than typically reported for other water wells in the United States. Some of the high gradients were associated with high natural gamma emissions. Groundwater flow was discernible in 5 of the 10 wells studied but only obscured the portion of the geothermal gradient signal where groundwater actually flowed through the well. Temperature gradients varied by mapped bedrock type but can also vary by differences in mineralogy or rock type within the wells.

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

    PubMed

    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.

  1. Reservoir characterization of marine and permafrost associated gas hydrate accumulations with downhole well logs

    USGS Publications Warehouse

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

    2000-01-01

    Gas volumes that may be attributed to a gas hydrate accumulation depend on a number of reservoir parameters, one of which, gas-hydrate saturation, can be assessed with data obtained from downhole well-logging devices. This study demonstrates that electrical resistivity and acoustic transit-time downhole log data can be used to quantify the amount of gas hydrate in a sedimentary section. Two unique forms of the Archie relation (standard and quick look relations) have been used in this study to calculate water saturations (S(w)) [gas-hydrate saturation (S(h)) is equal to (1.0 - S(w))] from the electrical resistivity log data in four gas hydrate accumulations. These accumulations are located on (1) the Blake Ridge along the Southeastern continental margin of the United States, (2) the Cascadia continental margin off the pacific coast of Canada, (3) the North Slope of Alaska, and (4) the Mackenzie River Delta of Canada. Compressional wave acoustic log data have also been used in conjunction with the Timur, modified Wood, and the Lee weighted average acoustic equations to calculate gas-hydrate saturations in all four areas assessed.

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

    SciTech Connect

    Shin, Jehyun; Hwang, Seho; Kim, Jongman; Won, Byeongho

    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.

  3. Calibration of NMR well logs from carbonate reservoirs with laboratory NMR measurements and μXRCT

    SciTech Connect

    Mason, Harris E.; Smith, Megan M.; Hao, Yue; Carroll, Susan A.

    2014-12-31

    The use of nuclear magnetic resonance (NMR) well log data has the potential to provide in-situ porosity, pore size distributions, and permeability of target carbonate CO₂ storage reservoirs. However, these methods which have been successfully applied to sandstones have yet to be completely validated for carbonate reservoirs. Here, we have taken an approach to validate NMR measurements of carbonate rock cores with independent measurements of permeability and pore surface area to volume (S/V) distributions using differential pressure measurements and micro X-ray computed tomography (μXRCT) imaging methods, respectively. We observe that using standard methods for determining permeability from NMR data incorrectly predicts these values by orders of magnitude. However, we do observe promise that NMR measurements provide reasonable estimates of pore S/V distributions, and with further independent measurements of the carbonate rock properties that universally applicable relationships between NMR measured properties may be developed for in-situ well logging applications of carbonate reservoirs.

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

    PubMed

    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.

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

    SciTech Connect

    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.

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

    SciTech Connect

    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.

  7. Fluid flow model of the Cerro Prieto geothermal field based on well log interpretation

    SciTech Connect

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

    1982-10-01

    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 he direction of geothermal fluid flow and the role of subsurface geologic features that control this movement.

  8. Investigation of Waikele well no 2401-01, Oahu, Hawaii; pumping test, well logs and water quality

    USGS Publications Warehouse

    Eyre, P.R.

    1983-01-01

    Field tests indicate that an abandoned well (No. 2401-01) near the confluence of Waikele and Kipapa Streams, Oahu, Hawaii, can be reactivated to produce potable water at a rate of 400-500 gallons per minute. Previous tests in 1946 and 1954 indicated that the well tapped the brackish transition zone which inderlies the Ghyben-Herzberg lens of the Pearl Harbor aquifer. Results of this study, based on geologic and geophysical logs of the wall, as well as on pumping test and water-quality data, indicate that the slightly brackish water produced by the well results from brackish irrigation return water. It does not appear that pumping from this well will cause seawater upconing or intrusion. (USGS)

  9. Magnetic susceptibility well-logging unit with single power supply thermoregulation system

    SciTech Connect

    Seeley, R. L.

    1985-11-05

    The magnetic susceptibility well-logging unit with single power supply thermoregulation system provides power from a single surface power supply over a well-logging cable to an integrated circuit voltage regulator system downhole. This voltage regulator system supplies regulated voltages to a temperature control system and also to a Maxwell bridge sensing unit which includes the solenoid of a magnetic susceptibility probe. The temperature control system is provided with power from the voltage regulator system and operates to permit one of several predetermined temperatures to be chosen, and then operates to maintain the solenoid of a magnetic susceptibility probe at this chosen temperature. The temperature control system responds to a temperature sensor mounted upon the probe solenoid to cause resistance heaters concentrically spaced from the probe solenoid to maintain the chosen temperature. A second temperature sensor on the probe solenoid provides a temperature signal to a temperature transmitting unit, which initially converts the sensed temperature to a representative voltage. This voltage is then converted to a representative current signal which is transmitted by current telemetry over the well logging cable to a surface electronic unit which then reconverts the current signal to a voltage signal.

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

    USGS Publications Warehouse

    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)

  11. Practical approach to estimate dynamic Young's modulus and Poisson's ratio using Passey's algorithm without sonic log in horizontal well

    NASA Astrophysics Data System (ADS)

    Hwang, Seho; Shin, Jehyun

    2013-04-01

    Shale gas evaluation process can be summarized as the selection of sweep spot intervals in the vertical borehole and determination of hydraulic fracturing zones in horizontal borehole. Brittleness index used in the selection of hydraulic fracturing interval is calculated from dynamic Young's modulus and Poisson's ratio of wireline logging and MWD/LWD data. Young's modulus and Poisson's ratio are calculated from the sonic and density log data, and therefore the MWD/LWD in the horizontal borehole should be included sonic log to estimate the dynamic elastic constants. This paper proposes a practical method to estimate the elastic moduli based on Passey's algorithm if we can't use the LWD sonic log in the horizontal borehole. To estimate the TOC (Total Organic Content) using the sonic-resistivity log, density-resistivity log, and neutron-resistivity log using Passey's algorithm we use the relationship between Delta log R values and core derived-LOM (Level of Maturity) data. Dynamic elastic constants in the horizontal well, i.e. in case of sweet spot zones, can be estimated using the relationships between P-wave velocity and elastic constants in the vertical well, and similarity between the calculated Delta log R values from sonic-resistivity log, density-resistivity log, and neutron-resistivity log, respectively. From two Passey's algorithms such as sonic-resistivity log, density-resistivity log relationships in the vertical well, we can derive the P-wave velocity equating the two Passey's algorithms based on the similarity. Then we can derive the dynamic elastic constants using the relationships between P-wave velocity and dynamic elastic constants. Finally we can estimate the brittleness index from the Young's modulus and Poisson's ratio. We expect that this practical method can be effectively applied if we can't use the LWD sonic logging data of the horizontal borehole.

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

    USGS Publications Warehouse

    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.

  13. Manchester code telemetry system for well logging using quasi-parallel inductive-capacitive resonance.

    PubMed

    Xu, Lijun; Chen, Jianjun; Cao, Zhang; Liu, Xingbin; Hu, Jinhai

    2014-07-01

    In this paper, a quasi-parallel inductive-capacitive (LC) resonance method is proposed to improve the recovery of MIL-STD-1553 Manchester code with several frequency components from attenuated, distorted, and drifted signal for data telemetry in well logging, and corresponding telemetry system is developed. Required resonant frequency and quality factor are derived, and the quasi-parallel LC resonant circuit is established at the receiving end of the logging cable to suppress the low-pass filtering effect caused by the distributed capacitance of the cable and provide balanced pass for all the three frequency components of the Manchester code. The performance of the method for various encoding frequencies and cable lengths at different bit energy to noise density ratios (Eb/No) have been evaluated in the simulation. A 5 km single-core cable used in on-site well logging and various encoding frequencies were employed to verify the proposed telemetry system in the experiment. Results obtained demonstrate that the telemetry system is feasible and effective to improve the code recovery in terms of anti-attenuation, anti-distortion, and anti-drift performances, decrease the bit error rate, and increase the reachable transmission rate and distance greatly.

  14. Manchester code telemetry system for well logging using quasi-parallel inductive-capacitive resonance

    NASA Astrophysics Data System (ADS)

    Xu, Lijun; Chen, Jianjun; Cao, Zhang; Liu, Xingbin; Hu, Jinhai

    2014-07-01

    In this paper, a quasi-parallel inductive-capacitive (LC) resonance method is proposed to improve the recovery of MIL-STD-1553 Manchester code with several frequency components from attenuated, distorted, and drifted signal for data telemetry in well logging, and corresponding telemetry system is developed. Required resonant frequency and quality factor are derived, and the quasi-parallel LC resonant circuit is established at the receiving end of the logging cable to suppress the low-pass filtering effect caused by the distributed capacitance of the cable and provide balanced pass for all the three frequency components of the Manchester code. The performance of the method for various encoding frequencies and cable lengths at different bit energy to noise density ratios (Eb/No) have been evaluated in the simulation. A 5 km single-core cable used in on-site well logging and various encoding frequencies were employed to verify the proposed telemetry system in the experiment. Results obtained demonstrate that the telemetry system is feasible and effective to improve the code recovery in terms of anti-attenuation, anti-distortion, and anti-drift performances, decrease the bit error rate, and increase the reachable transmission rate and distance greatly.

  15. Use of Electromagnetic Acoustic Transducers (emats) for Cement Bond Logging of Gas Storage Wells

    NASA Astrophysics Data System (ADS)

    Bolshakov, A. O.; Domangue, E. J.; Barolak, J. G.; Patterson, D. J.

    2008-02-01

    According to the Department of Energy (DOE), there are approximately 110 operators maintaining more than 17,000 gas storage wells in over 415 underground storage facilities across the USA. In virtually every application, steel casing, cemented into place, serves to isolate the well from the underground formations. The process of cementing wellbore casing provides two major benefits: 1) cement prevents gas migration between the casing and formation; 2) cement transfers stress from the casing to the formation, increasing the effective strength and working pressure of the casing. Current cement evaluation techniques use an acoustic wave generated and received by a logging tool within the wellbore to detect cement placed outside the casing. These techniques rely on fluid in the casing to provide acoustic coupling between the logging tool and the casing and therefore are unable to operate in gas-filled boreholes. This paper details efforts to confirm the validity and applicability of the use of EMATs for evaluating cement in gas-filled boreholes. The methods and techniques proposed for the cement bond logging using EMATs are confirmed and validated based on the results obtained from the numerical modeling and experiments with physical cement models. Partial funding for this investigation was provided by the DOE and Gas Storage Technology Consortium.

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

    NASA Astrophysics Data System (ADS)

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

    2016-09-01

    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 over-smoothing caused by the imperfect velocity interpolation. The anomaly and over-smoothing 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.

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

    NASA Astrophysics Data System (ADS)

    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.

  18. Preliminary report on geophysical well-logging activity on the Salton Sea Scientific Drilling Project, Imperial Valley, California

    USGS Publications Warehouse

    Paillet, Frederick L.; Morin, R.H.; Hodges, H.E.

    1986-01-01

    The Salton Sea Scientific Drilling Project has culminated in a 10,564-ft deep test well, State 2-14 well, in the Imperial Valley of southern California. A comprehensive scientific program of drilling, coring, and downhole measurements, which was conducted for about 5 months, has obtained much scientific information concerning the physical and chemical processes associated with an active hydrothermal system. This report primarily focuses on the geophysical logging activities at the State 2-14 well and provides early dissemination of geophysical data to other investigators working on complementary studies. Geophysical-log data were obtained by a commercial logging company and by the U.S. Geological Survey (USGS). Most of the commercial logs were obtained during three visits to the site; only one commercial log was obtained below a depth of 6,000 ft. The commercial logs obtained were dual induction, natural gamma, compensated neutron formation density, caliper and sonic. The USGS logging effort consisted of four primary periods, with many logs extending below a depth of 6,000 ft. The USGS logs obtained were temperature, caliper, natural gamma, gamma spectral, epithermal neutron, acoustic velocity, full-waveform, and acoustic televiewer. Various problems occurred throughout the drilling phase of the Salton Sea Scientific Drilling Project that made successful logging difficult: (1) borehole constrictions, possibly resulting from mud coagulation, (2) maximum temperatures of about 300 C, and (3) borehole conditions unfavorable for logging because of numerous zones of fluid loss, cement plugs, and damage caused by repeated trips in and out of the hole. These factors hampered and compromised logging quality at several open-hole intervals. The quality of the logs was dependent on the degree of probe sophistication and sensitivity to borehole-wall conditions. Digitized logs presented were processed on site and are presented in increments of 1,000 ft. A summary of the numerous

  19. Self-optimizing Monte Carlo method for nuclear well logging simulation

    NASA Astrophysics Data System (ADS)

    Liu, Lianyan

    1997-09-01

    In order to increase the efficiency of Monte Carlo simulation for nuclear well logging problems, a new method has been developed for variance reduction. With this method, an importance map is generated in the regular Monte Carlo calculation as a by-product, and the importance map is later used to conduct the splitting and Russian roulette for particle population control. By adopting a spatial mesh system, which is independent of physical geometrical configuration, the method allows superior user-friendliness. This new method is incorporated into the general purpose Monte Carlo code MCNP4A through a patch file. Two nuclear well logging problems, a neutron porosity tool and a gamma-ray lithology density tool are used to test the performance of this new method. The calculations are sped up over analog simulation by 120 and 2600 times, for the neutron porosity tool and for the gamma-ray lithology density log, respectively. The new method enjoys better performance by a factor of 4~6 times than that of MCNP's cell-based weight window, as per the converged figure-of-merits. An indirect comparison indicates that the new method also outperforms the AVATAR process for gamma-ray density tool problems. Even though it takes quite some time to generate a reasonable importance map from an analog run, a good initial map can create significant CPU time savings. This makes the method especially suitable for nuclear well logging problems, since one or several reference importance maps are usually available for a given tool. Study shows that the spatial mesh sizes should be chosen according to the mean-free-path. The overhead of the importance map generator is 6% and 14% for neutron and gamma-ray cases. The learning ability towards a correct importance map is also demonstrated. Although false-learning may happen, physical judgement can help diagnose with contributon maps. Calibration and analysis are performed for the neutron tool and the gamma-ray tool. Due to the fact that a very

  20. Calibration facilities at Hanford for gamma-ray and fission-neutron well logging

    SciTech Connect

    Stromswold, D.C.

    1994-07-01

    Well-logging tools that detect gamma rays emitted from earth formations need to be calibrated in appropriate facilities to provide quantitative assessments of concentrations o radionuclides based on detected gamma rays. These facilities are typically special models having a hole to insert tools and having sufficient physical size to simulate actual earth formations containing known amounts of radionuclides. The size, generally 3 to 5 feet in diameter and 4 to 6 feet tall, is such that the source of radiation appears infinite in extent to a tool detecting the radiation inside the model. Such models exist at Hanford as concrete cylinders having a central borehole and containing known, enhanced amounts of K, U, and Th. Data collected in these models allow calibration of the logging system to measure radionuclide concentrations in formations around boreholes in the field. The accuracy of the calculated field concentrations depends on the correctness of the original calibration, the statistical precision of the data, and the similarity of the logging conditions to the calibration conditions. Possible methods for analyzing the data collected in the calibration facilities are presented for both spectral and total-count gamma-ray systems. Corrections are typically needed for the effects of steel casing in boreholes and the presence of water rather than air in the holes. Data collected in the calibration models with various steel casings and borehole fluids allow such correction factors to be determined.

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

    NASA Astrophysics Data System (ADS)

    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

  2. High-voltage supply for neutron tubes in well-logging applications

    DOEpatents

    Humphreys, D.R.

    1982-09-15

    A high voltage supply is provided for a neutron tube used in well logging. The biased pulse supply of the invention combines DC and full pulse techniques and produces a target voltage comprising a substantial negative DC bias component on which is superimposed a pulse whose negative peak provides the desired negative voltage level for the neutron tube. The target voltage is preferably generated using voltage doubling techniques and employing a voltage source which generates bipolar pulse pairs having an amplitude corresponding to the DC bias level.

  3. Seismic and well log characterization of fractures for geothermal exploration in hard rocks

    NASA Astrophysics Data System (ADS)

    Aleardi, Mattia; Mazzotti, Alfredo; Tognarelli, Andrea; Ciuffi, Simonetta; Casini, Michele

    2015-10-01

    We study the well log and seismic responses of intensively fractured portions of deep intrusive/metamorphic rocks in southern Tuscany (Italy), which constitute the main drilling targets of the geothermal exploration in the Larderello-Travale area. In particular, the target we consider is located near the contact between a deep Pliocene granitic intrusion and the overlying Palaeozoic metamorphic basement. Sonic, density and borehole image logs are analysed together with post-stack reflection attributes and reflection amplitude versus source to receiver azimuth (AVAZ) responses. It turns out that the intense fracturing in the contact zone causes significant decreases in the density and P-wave velocity, and that fracture planes exhibit very high dips and a common preferential direction. The fractured zone found by the well coincides with peculiar alignments of high-amplitude signals in the 3-D seismic stack volume, which are particularly visible on the reflection strength and instantaneous phase time slices. The normal incidence synthetic seismogram based on the log data matches the observed stack trace nearest to the well and confirms that the high-amplitude reflection occurs at the fractured zone. We then consider the pre-stack domain to study the same reflections on bin gathers that are close to the well and coincident with the anomalies in the 3-D volume. In particular, we perform AVAZ analysis to detect possible anisotropic features in the reflected amplitudes due to the preferential orientation of the fractures, and we study the effect of crack density on the seismic responses and on velocity and density values. To this end, we build simplified models where a level with vertical fractures is encased in tight isotropic rocks. Notwithstanding the suboptimal quality of the seismic data, we estimate the overall matching between the borehole information and the seismic response as fair. In particular, the azimuthal amplitude variation of the reflections from the

  4. Electrical resistivity well-logging system with solid-state electronic circuitry

    USGS Publications Warehouse

    Scott, James Henry; Farstad, Arnold J.

    1977-01-01

    An improved 4-channel electrical resistivity well-logging system for use with a passive probe with electrodes arranged in the 'normal' configuration has been designed and fabricated by Westinghouse Electric Corporation to meet technical specifications developed by the U.S. Geological Survey. Salient features of the system include solid-state switching and current regulation in the transmitter circuit to produce a constant-current source square wave, and synchronous solid-state switching and sampling of the potential waveform in the receiver circuit to provide an analog dc voltage proportions to the measured resistivity. Technical specifications and design details are included in this report.

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

    PubMed

    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.

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

    PubMed

    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. PMID:26275816

  7. Thin walled liner hanger equipment enables well deepening project

    SciTech Connect

    Sutherland, J.; Weaver, C.; Aiello, P.

    1996-12-31

    Shell Canada estimates that a thin-walled, slimhole design for liner equipment can save up to $3--4 million (US) per well in deep re-entry applications by allowing existing wells to be deepened (or sidetracked) rather than drilling new wells from surface. The design makes it possible to reenter existing wells, successfully isolate depleted zones, and deepen the well into virgin-pressured reservoirs. The design includes thin-walled, close-tolerance liner hangers, liner top packers, tie-back seal assemblies, and liner setting sleeves that provide reasonable burst and collapse resistance while maintaining an inside diameter to facilitate drilling deep, deviated 4-3/4 in. hole with a tapered 2-7/8 in. x 3-1/2 in. drill string. The authors will explain the design and the rationale behind it, and illustrate its value, using case studies from Shell Canada`s Waterton field as examples. In this field, gas-producing wells originally drilled in the 1950s, `60s and `70s to depths of up to 14,760 ft (4,500 m) were completed with perforations in 7 in. casing and open hole. These wells are now being reentered in an attempt to tap new reserves. The reentries encounter particularly challenging sour-gas/low-temperature/diverse-formation-pressure conditions. The objective of the reentry program is to seal off the depleted bottom zones of the wells and tap into the same fault-repeated formations at virgin pressure, at a deeper level.

  8. Unzen Volcano Scientific Drilling: Well Logging Data of the USDP-4

    NASA Astrophysics Data System (ADS)

    Kajiwara, T.; Ikeda, R.; Nakada, S.; Uto, K.; Nishi, M.

    2004-12-01

    The Unzen Volcano Scientific Drilling Project (USDP) has been conducted to target the magma conduit shortly after the 1990-1995 eruption. After two drillings of 752 m and 1463 m deep at the flank site, the conduit surveying well (USDP-4) was drilled to the depth of 1995.75 m in the mountainside to clarify the ascending and degassing mechanisms of magma. We have conducted physical logging in the USDP-4 well to elucidate the structure and material properties in and around the conduit. The logging items are as follows: Gamma Ray (167 to 1780 m), Resistivity (167 to 1795 m), Self-Potential (167 to 1775 m), Density (392 to 1782 m), Neutron Porosity (770 to 1777 m), Sonic velocity (392 to 1787 m), Full-bore Formation Micro Imager (FMI : 167 to 1540 m), Formation Micro Scanner (FMS : 1550 to 1791.5 m) and VSP (237 to 737m). Because of the high inclination of this well (Sakuma et al., this meeting), we used the Tough Logging Condition System (TLCS) below the depth of 800 m where the well inclination is up to 70 degrees. We had some concern because of a possible well collapse and high temperatures at the conduit zone before drilling. However, a good well condition and low temperature enabled us to obtain good logging data from this well. Comparing the logging data and lithology, determined mainly from drilled cores and cuttings (Nakada et al., this meeting), we can make clear the features of its formation and material properties found within the well. Gamma Ray varies between 40 API to 100 API, with the high (90 to 100 API) value coinciding with a lava dike. Resistivity structure can be classified into 5 layers. The value of resistivity above 240 m, 240 to 550 m, 550 to 1100 m, 1100 to 1760 m and below 1760 m are a few hundred ohm-m, 500 to 1000 ohm-m, about 100 ohm-m, about 10 ohm-m, about 100 ohm-m, respectively. The lava dike indicates a characteristic feature of about 100 ohm-m even though it is distributed in the 10 ohm-m layer. P-wave velocity varies 3 to 5 km

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

    NASA Astrophysics Data System (ADS)

    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.

  10. Induction conductivity and natural gamma logs collected in 15 wells at Camp Stanley Storage Activity, Bexar County, Texas

    USGS Publications Warehouse

    Stanton, Gregory P.

    2005-01-01

    The U.S. Geological Survey, in cooperation with the Camp Stanley Storage Activity conducted electromagnetic induction conductivity and natural gamma logging of 15 selected wells on the Camp Stanley Storage Activity, located in northern Bexar County, Texas, during March 28-30, 2005. In late 2004, a helicopter electromagnetic survey was flown of the Camp Stanley Storage Activity as part of a U.S. Geological Survey project to better define subsurface geologic units, the structure, and the catchment area of the Trinity aquifer. The electromagnetic induction conductivity and natural gamma log data in this report were collected to constrain the calculation of resistivity depth sections and to provide subsurface controls for interpretation of the helicopter electromagnetic data collected for the Camp Stanley Storage Activity. Logs were recorded digitally while moving the probe in an upward direction to maintain proper depth control. Logging speed was no greater than 30 feet per minute. During logging, a repeat section of at least 100 feet was recorded to check repeatability of log responses. Several of the wells logged were completed with polyvinyl chloride casing that can be penetrated by electromagnetic induction fields and allows conductivity measurement. However, some wells were constructed with steel centralizers and stainless steel screen that caused spikes on both conductivity and resulting resistivity log curves. These responses are easily recognizable and appear at regular intervals on several logs.

  11. Calibration of NMR well logs from carbonate reservoirs with laboratory NMR measurements and μXRCT

    DOE PAGES

    Mason, Harris E.; Smith, Megan M.; Hao, Yue; Carroll, Susan A.

    2014-12-31

    The use of nuclear magnetic resonance (NMR) well log data has the potential to provide in-situ porosity, pore size distributions, and permeability of target carbonate CO₂ storage reservoirs. However, these methods which have been successfully applied to sandstones have yet to be completely validated for carbonate reservoirs. Here, we have taken an approach to validate NMR measurements of carbonate rock cores with independent measurements of permeability and pore surface area to volume (S/V) distributions using differential pressure measurements and micro X-ray computed tomography (μXRCT) imaging methods, respectively. We observe that using standard methods for determining permeability from NMR data incorrectlymore » predicts these values by orders of magnitude. However, we do observe promise that NMR measurements provide reasonable estimates of pore S/V distributions, and with further independent measurements of the carbonate rock properties that universally applicable relationships between NMR measured properties may be developed for in-situ well logging applications of carbonate reservoirs.« less

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

    SciTech Connect

    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.

  13. Logs and completion data for water and mass balance wells in Mortandad and Ten Site Canyons

    SciTech Connect

    McLin, S.G.; Purtymun, W.D.; Swanton, A.S.; Koch, R.J.

    1997-10-01

    Twenty-four monitoring wells were drilled and completed in December 1994 as part of a water and mass balance study for the shallow perched aquifer in the Mortandad Canyon alluvium and in the lower part of Ten-Site Canyon. The wells penetrated the alluvium containing the aquifer and were completed into the top of the weathered tuff. Twelve of these wells encountered the Tshirege Member (Cooing Unit 1 g) of the Bandelier Tuff below the canyon alluvium, while ten wells made contact with the Cerro Toledo interval, which lies between the Tshirege and Otowi Members of the Bandelier Tuff. The remaining two wells were completed into the alluvium above the weathered tuff contact. These wells provide access for continuous water level measurement and water sampling. Data from these new wells will be used to determine changes in alluvial aquifer water storage, water quality sampling, and estimation of seepage into the unsaturated Bandelier Tuff below the alluvium. This report documents drilling activities and well completion logs for the water and mass balance study. These wells also provide critical new data for fourteen north-south vertical cross-sections constructed for the canyon alluvium.

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

    NASA Astrophysics Data System (ADS)

    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.

  15. 40 CFR 146.87 - Logging, sampling, and testing prior to injection well operation.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... installed; and (ii) A cement bond and variable density log to evaluate cement quality radially, and a... cement bond and variable density log, and a temperature log after the casing is set and cemented. (4) A... confining zone(s): (1) Fracture pressure; (2) Other physical and chemical characteristics of the...

  16. 40 CFR 146.87 - Logging, sampling, and testing prior to injection well operation.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... installed; and (ii) A cement bond and variable density log to evaluate cement quality radially, and a... cement bond and variable density log, and a temperature log after the casing is set and cemented. (4) A... confining zone(s): (1) Fracture pressure; (2) Other physical and chemical characteristics of the...

  17. 40 CFR 146.87 - Logging, sampling, and testing prior to injection well operation.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... installed; and (ii) A cement bond and variable density log to evaluate cement quality radially, and a... cement bond and variable density log, and a temperature log after the casing is set and cemented. (4) A... confining zone(s): (1) Fracture pressure; (2) Other physical and chemical characteristics of the...

  18. 40 CFR 146.87 - Logging, sampling, and testing prior to injection well operation.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... installed; and (ii) A cement bond and variable density log to evaluate cement quality radially, and a... cement bond and variable density log, and a temperature log after the casing is set and cemented. (4) A... confining zone(s): (1) Fracture pressure; (2) Other physical and chemical characteristics of the...

  19. Determining geophysical properties from well log data using artificial neural networks and fuzzy inference systems

    NASA Astrophysics Data System (ADS)

    Chang, Hsien-Cheng

    Two novel synergistic systems consisting of artificial neural networks and fuzzy inference systems are developed to determine geophysical properties by using well log data. These systems are employed to improve the determination accuracy in carbonate rocks, which are generally more complex than siliciclastic rocks. One system, consisting of a single adaptive resonance theory (ART) neural network and three fuzzy inference systems (FISs), is used to determine the permeability category. The other system, which is composed of three ART neural networks and a single FIS, is employed to determine the lithofacies. The geophysical properties studied in this research, permeability category and lithofacies, are treated as categorical data. The permeability values are transformed into a "permeability category" to account for the effects of scale differences between core analyses and well logs, and heterogeneity in the carbonate rocks. The ART neural networks dynamically cluster the input data sets into different groups. The FIS is used to incorporate geologic experts' knowledge, which is usually in linguistic forms, into systems. These synergistic systems thus provide viable alternative solutions to overcome the effects of heterogeneity, the uncertainties of carbonate rock depositional environments, and the scarcity of well log data. The results obtained in this research show promising improvements over backpropagation neural networks. For the permeability category, the prediction accuracies are 68.4% and 62.8% for the multiple-single ART neural network-FIS and a single backpropagation neural network, respectively. For lithofacies, the prediction accuracies are 87.6%, 79%, and 62.8% for the single-multiple ART neural network-FIS, a single ART neural network, and a single backpropagation neural network, respectively. The sensitivity analysis results show that the multiple-single ART neural networks-FIS and a single ART neural network possess the same matching trends in

  20. MCNP (Monte Carlo Neutron Photon) capabilities for nuclear well logging calculations

    SciTech Connect

    Forster, R.A.; Little, R.C.; Briesmeister, J.F.

    1989-01-01

    The Los Alamos Radiation Transport Code System (LARTCS) consists of state-of-the-art Monte Carlo and discrete ordinates transport codes and data libraries. The general-purpose continuous-energy Monte Carlo code MCNP (Monte Carlo Neutron Photon), part of the LARTCS, provides a computational predictive capability for many applications of interest to the nuclear well logging community. The generalized three-dimensional geometry of MCNP is well suited for borehole-tool models. SABRINA, another component of the LARTCS, is a graphics code that can be used to interactively create a complex MCNP geometry. Users can define many source and tally characteristics with standard MCNP features. The time-dependent capability of the code is essential when modeling pulsed sources. Problems with neutrons, photons, and electrons as either single particle or coupled particles can be calculated with MCNP. The physics of neutron and photon transport and interactions is modeled in detail using the latest available cross-section data. A rich collections of variance reduction features can greatly increase the efficiency of a calculation. MCNP is written in FORTRAN 77 and has been run on variety of computer systems from scientific workstations to supercomputers. The next production version of MCNP will include features such as continuous-energy electron transport and a multitasking option. Areas of ongoing research of interest to the well logging community include angle biasing, adaptive Monte Carlo, improved discrete ordinates capabilities, and discrete ordinates/Monte Carlo hybrid development. Los Alamos has requested approval by the Department of Energy to create a Radiation Transport Computational Facility under their User Facility Program to increase external interactions with industry, universities, and other government organizations. 21 refs.

  1. Detailed evaluation of gas hydrate reservoir properties using JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well downhole well-log displays

    USGS Publications Warehouse

    Collett, T.S.

    1999-01-01

    The JAPEX/JNOC/GSC Mallik 2L-38 gas hydrate research well project was designed to investigate the occurrence of in situ natural gas hydrate in the Mallik area of the Mackenzie Delta of Canada. Because gas hydrate is unstable at surface pressure and temperature conditions, a major emphasis was placed on the downhole logging program to determine the in situ physical properties of the gas-hydrate-bearing sediments. Downhole logging tool strings deployed in the Mallik 2L-38 well included the Schlumberger Platform Express with a high resolution laterolog, Array Induction Imager Tool, Dipole Shear Sonic Imager, and a Fullbore Formation Microlmager. The downhole log data obtained from the log- and core-inferred gas-hydrate-bearing sedimentary interval (897.25-1109.5 m log depth) in the Mallik 2L-38 well is depicted in a series of well displays. Also shown are numerous reservoir parameters, including gas hydrate saturation and sediment porosity log traces, calculated from available downhole well-log and core data. The gas hydrate accumulation delineated by the Mallik 2L-38 well has been determined to contain as much as 4.15109 m3 of gas in the 1 km2 area surrounding the drill site.

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

    PubMed

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

    2014-01-01

    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°. PMID:24859028

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

    PubMed Central

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

    2014-01-01

    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°. PMID:24859028

  4. The feasibility of well-logging measurements of arsenic levels using neutron-activation analysis

    USGS Publications Warehouse

    Oden, C.P.; Schweitzer, J.S.; McDowell, G.M.

    2006-01-01

    Arsenic is an extremely toxic metal, which poses a significant problem in many mining environments. Arsenic contamination is also a major problem in ground and surface waters. A feasibility study was conducted to determine if neutron-activation analysis is a practical method of measuring in situ arsenic levels. The response of hypothetical well-logging tools to arsenic was simulated using a readily available Monte Carlo simulation code (MCNP). Simulations were made for probes with both hyperpure germanium (HPGe) and bismuth germanate (BGO) detectors using accelerator and isotopic neutron sources. Both sources produce similar results; however, the BGO detector is much more susceptible to spectral interference than the HPGe detector. Spectral interference from copper can preclude low-level arsenic measurements when using the BGO detector. Results show that a borehole probe could be built that would measure arsenic concentrations of 100 ppm by weight to an uncertainty of 50 ppm in about 15 min. ?? 2006 Elsevier Ltd. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

    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

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

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

    2014-01-01

    Collection and integrated analysis of drilling and geophysical logs provided an efficient and effective means for characterizing the geohydrologic framework and conditions penetrated by the tophole at the selected oil-and-gas well site. The logging methods and lessons learned at this well site could be applied at other oil-and-gas drilling sites to better characterize the shallow subsurface with the overall goal of protecting freshwater aquifers during hydrocarbon development.

  8. Prediction of gas production using well logs, Cretaceous of north-central Montana

    USGS Publications Warehouse

    Hester, T.C.

    1999-01-01

    Cretaceous gas sands underlie much of east-central Alberta and southern Saskatchewan, eastern Montana, western North Dakota, and parts of South Dakota and Wyoming. Estimates of recoverable biogenic methane from these rocks in the United States are as high as 91 TCF. In northern Montana, current production is localized around a few major structural features, while vast areas in between these structures are not being exploited. Although the potential for production exists, the lack of commercial development is due to three major factors: 1) the lack of pipeline infrastructure; 2) the lack of predictable and reliable rates of production; and 3) the difficulty in recognizing and selecting potentially productive gas-charged intervals. Unconventional (tight), continuous-type reservoirs, such as those in the Cretaceous of the northern Great Plains, are not well suited for conventional methods of formation evaluation. Pay zones frequently consist only of thinly laminated intervals of sandstone, silt, shale stringers, and disseminated clay. Potential producing intervals are commonly unrecognizable on well logs, and thus are overlooked. To aid in the identification and selection of potential producing intervals, a calibration system is developed here that empirically links the 'gas effect' to gas production. The calibration system combines the effects of porosity, water saturation, and clay content into a single 'gas-production index' (GPI) that relates the in-situ rock with production potential. The fundamental method for isolating the gas effect for calibration is a crossplot of neutron porosity minus density porosity vs gamma-ray intensity. Well-log and gas-production data used for this study consist of 242 perforated intervals from 53 gas-producing wells. Interval depths range from about 250 to 2400 ft. Gas volumes in the peak calendar year of production range from about 4 to 136 MMCF. Nine producing formations are represented. Producing-interval data show that porosity

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

    USGS Publications Warehouse

    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.

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

    NASA Astrophysics Data System (ADS)

    Singh, Amrita; Maiti, Saumen; Tiwari, R. K.

    2016-06-01

    Identification of sharp and discontinuous lithological boundaries from well log signal stemming from heterogeneous subsurface structures assumes a special significance in geo-exploration studies. Well log data acquired from various geological settings generally display nonstationary/nonlinear characteristics with varying wavelengths and frequencies. Modelling of such complex well-log signals using the conventional signal processing techniques either fails to catch-up abrupt boundaries or at the best, do not provide precise information on insidious lithological discontinuities. In this paper, we have proposed a new wavelet transform-based algorithm to model the abrupt discontinuous changes from well log data by taking care of nonstationary characteristics of the signal. Prior to applying the algorithm on the geophysical well data, we analyzed the distribution of wavelet coefficients using synthetic signal generated by the first order nonstationary auto-regressive model and then applied the method on actual well log dataset obtained from the KTB bore hole, Germany. Besides identifying the formation of layered boundaries, the underlying method also maps some additional formation boundaries, which were hitherto undetected at the KTB site. The results match well with known geological lithostratigraphy and will be useful for constraining the future model of KTB bore hole data.

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Analysis of geophysical well logs obtained in the State 2-14 borehole, Salton Sea geothermal area, California

    USGS Publications Warehouse

    Paillet, Frederick L.; Morin, R.H.

    1988-01-01

    A complete suite of conventional geophysical well logs was obtained in the upper part of a 3220-m-deep borehole drilled into geothermally altered alluvial sediments on the southeastern edge of the Salton Sea. Geophysical logs obtained in the State 2-14 borehole indicate that neutron porosity, gamma-gamma, and deep-induction logs provide useful information on lithologic trends with depth. The natural gamma log contains almost continuous, high-frequency fluctuations that obscure lithologic trends and that may be related to recent radioisotope redistribution and departure from radiometric equilibrium. Acoustic transit time logs give unrealistically low in situ compressional velocities ranging from 1.8 to 3.0 km/s, whereas acoustic waveform logs indicate that sediment compressional velocities range from less than 3.0 km/s shallower than 1000 m in depth to almost 5.0 km/s at depths greater than 2000 m. Analyses indicate that most log values lie between two lithologic end points: an electrically conductive claystone with moderate neutron porosity, but no effective porosity, and an electrically nonconductive, fully cemented siltstone that has small but finite porosity. -from Authors

  13. Geophysical well-log analysis of fractured crystalline rocks at East Bull Lake, Ontario, Canada

    USGS Publications Warehouse

    Paillet, Frederick L.; Hess, A.E.

    1986-01-01

    Various conventional geophysical borehole measurements were made in conjunction with measurements using a recently designed, low-frequency, acoustic-waveform probe and slow velocity flowmeter for characterization of a fractured mafic intrusion in southern Ontario, Canada. Conventional geophysical measurements included temperature, caliper, gamma, acoustic, single-point resistance, and acoustic televiewer logs. Hole stability problems prevented the use of neutron and gamma-gamma logs, because these logs require that a radioactive source be lowered into the borehole. Measurements were made in three boreholes as much as 850 m deep and penetrating a few tens of meters into granitic basement. All rocks within the mafic intrusion were characterized by minimal gamma radiation and acoustic velocities of about 6.9 km/sec. The uniformity of the acoustic velocities and the character of acoustic-waveform logs made with a conventional high-frequency logging source correlated with the density of fractures evident on televiewer logs. Sample intervals of high-frequency waveform logs were transformed into interpretations of effective fracture opening using a recent model for acoustic attenuation in fractured rocks. The new low-frequency sparker source did not perform as expected at depths below 250 m because of previously unsuspected problems with source firing under large hydrostatic heads. A new heat-pulse, slow velocity flowmeter was used to delineate in detail the flow regime indicated in a general way by temperature logs. The flowmeter measurements indicated that water was entering 2 of the boreholes at numerous fractures above a depth of 200 m, with flow in at least 2 of the boreholes exiting through large isolated fractures below a depth of 400 m. (Author 's abstract)

  14. Results of well-bore flow logging for six water-production wells completed in the Santa Fe Group aquifer system, Albuquerque, New Mexico, 1996-98

    USGS Publications Warehouse

    Thorn, Conde R.

    2000-01-01

    Over the last several years, an improved conceptual understanding of the aquifer system in the Albuquerque area, New Mexico, has lead to better knowledge about the location and extent of the aquifer system. This information will aid with the refinement of ground-water simulation and with the location of sites for future water-production wells. With an impeller-type flowmeter, well-bore flow was logged under pumping conditions along the screened interval of the well bore in six City of Albuquerque water-production wells: the Ponderosa 3, Love 6, Volcano Cliffs 1, Gonzales 2, Zamora 2, and Gonzales 3 wells. From each of these six wells, a well-bore flow log was collected that represents the cumulative upward well-bore flow. Evaluation of the well-bore flow log for each well allowed delineation of the more productive zones supplying water to the well along the logged interval. Yields from the more productive zones in the six wells ranged from about 70 to 880 gallons per minute. The lithology of these zones is predominantly gravel and sand with varying amounts of sandy clay.

  15. Geophysical logging studies in the Snake River Plain Aquifer at the Idaho National Engineering Laboratory: Wells 44, 45, and 46

    SciTech Connect

    Morin, R.H.; Paillet, F.L.; Taylor, T.A.; Barrash, W.

    1993-05-01

    A geophysical logging program was undertaken to vertically profile changes in the hydrology and hydrochemistry of the Snake River Plain aquifer underlies the Idaho National Engineering Laboratory (INEL). Field investigations were concentrated within an area west of the Idaho Chemical Processing Plant (ICPP) in three wells that penetrated the upper 190 feet of the aquifer. The logs obtained in these wells consisted of temperature, caliper, nuclear (neutron porosity and gamma-gama density), natural gamma, borehole televiewer, gamma spectral, and thermal flowmeter (with and without pumping). The nuclear, caliper, and televiewer logs are used to delineate individual basalt flows or flow units and to recognize breaks between flows or flow units at interflow contact zones and sedimentary interbeds. The temperature logs and flowmeter measurements obtained under ambient hydraulic head conditions identified upward fluid-circulation patterns in the three wells. Gamma-spectral analyses performed at several depths in each well showed that the predominant source of gamma radiation in the formation at this site originates mainly from potassium ({sup 40}K). However, {sup 137}Cesium was detected at 32 feet below land surface in well 45. An empirical investigation of the effect of source-receiver spacing on the response of the neutron-porosity logging tool was attempted in an effort to understand the conditions under which this tool might be applied to large-diameter boreholes in-unsaturated formations.

  16. Geothermal-well completions: a survey and technical evaluation of existing equipment and needs

    SciTech Connect

    Nicholson, J.E.; Snyder, R.E.

    1982-07-01

    The geothermal environment and associated well completion problems are reviewed. Existing well completion equipment is surveyed and limitations are identified. A technical evaluation of selected completion equipment is presented. The technical evaluation concentrates on well cementing equipment and identifies potential failure mechanisms which limit the effectiveness of these tools. Equipment employed in sand control, perforating, and corrosion control are identified as potential subjects for future technical evaluation.

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

    NASA Astrophysics Data System (ADS)

    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).

  18. Possible New Well-Logging Tool Using Positron Annihilation Spectroscopy to Detect TOC in Source Rocks

    NASA Astrophysics Data System (ADS)

    Patterson, Casey; Quarles, C. A.; Breyer, J. A.

    2001-10-01

    Possible New Well-Logging Tool Using Positron Annihilation Spectroscopy to Detect Total Organic Carbon (TOC) in Source Rocks PATTERSON, C., Department of Geology, Department of Physics, Texas Christian University, QUARLES, C.A., Department of Physics, Texas Christian University, Fort Worth, Texas, BREYER, J.A., Department of Geology, Texas Christian University, Fort, Worth, Texas. The positron produces two gamma rays upon annihilation with an electron. Depending on the momentum of the electron, the two resulting photons are shifted from the initial electron rest mass energy by the Doppler effect. We measure the distribution of gamma ray energies produced by annihilation on a petroleum source rock core. Core from the Mitchell Energy well T.P. Sims 2 of the Barnett Shale located in Wise County, Texas, is under study. Apparatus for the experiment consists of an Ortec Ge detector. The source used for the experiment is Ge68, which undergoes beta decay and produces the positrons that penetrate the core. It is placed on the middle of the core and covered with a small, annealed NiCu plate to prevent unnecessary background from the positrons annihilating with electrons other than in the core. Distance between the source and the detector is fixed at 6.75 inches. Measurements were made in specific locations at 2 inch increments for approximately an hour and a half where the predetermined Total Organic Carbon (TOC) values were made. Future studies involve an overall correlation of the core between experimental readings and TOC, including corrections for changes in grain size and lithology. Additional research has shown no distinct correlation between grain size and distribution of energies across the targeted spectrum. Additional corrections should be made for the decay in activity of the source. Future research also includes the determination for optimum time and distance for the source from the core. A long-term goal for the experiment is to develop an effective down

  19. Calculation of Monte Carlo importance functions for use in nuclear-well logging calculations

    SciTech Connect

    Soran, P.D.; McKeon, D.C.; Booth, T.E.; Schlumberger Well Services, Houston, TX; Los Alamos National Lab., NM )

    1989-07-01

    Importance sampling is essential to the timely solution of Monte Carlo nuclear-logging computer simulations. Achieving minimum variance (maximum precision) of a response in minimum computation time is one criteria for the choice of an importance function. Various methods for calculating importance functions will be presented, new methods investigated, and comparisons with porosity and density tools will be shown. 5 refs., 1 tab.

  20. Automated robotic equipment for ultrasonic inspection of pressurizer heater wells

    SciTech Connect

    Nachbar, H.D.; DeRossi, R.S.; Mullins, L.E.

    1991-12-31

    A robotic device for remotely inspecting pressurizer heater wells is provided which has the advantages of quickly, precisely, and reliably acquiring data at reasonable cost while also reducing radiation exposure of an operator. The device comprises a probe assembly including a probe which enters a heater well, gathers data regarding the condition of the heater well and transmits a signal carrying that data; a mounting device for mounting the probe assembly at the opening of the heater well so that the probe can enter the heater well; a first motor mounted on the mounting device for providing movement of the probe assembly in an axial direction; and a second motor mounted on the mounting device for providing rotation of the probe assembly. This arrangement enables full inspection of the heater well to be carried out.

  1. Automated robotic equipment for ultrasonic inspection of pressurizer heater wells

    SciTech Connect

    Nachbar, Henry D.; DeRossi, Raymond S.; Mullins, Lawrence E.

    1993-01-01

    A robotic device for remotely inspecting pressurizer heater wells is provided which has the advantages of quickly, precisely, and reliably acquiring data at reasonable cost while also reducing radiation exposure of an operator. The device comprises a prober assembly including a probe which enters a heater well, gathers data regarding the condition of the heater well and transmits a signal carrying that data; a mounting device for mounting the probe assembly at the opening of the heater well so that the probe can enter the heater well; a first motor mounted on the mounting device for providing movement of the probe assembly in an axial direction; and a second motor mounted on the mounting device for providing rotation of the probe assembly. This arrangement enables full inspection of the heater well to be carried out.

  2. Drilling, construction, caliper-log, and specific-conductance data for well 3-3406-12, Twin Bridge Road deep monitor well, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The Twin Bridge Road deep monitor well (State well number 3-3406-12) was drilled about 2,000 feet northeast of Weed Circle in the town of Haleiwa. The well is on agricultural land. The well penetrates through the freshwater lens and into the freshwater-saltwater transition zone of the Waialua ground-water area to an elevation of -596 feet below mean sea level. Well-construction data, logs of drilling notes, geologic descriptions for the samples, caliper-log, and specific-conductance data are presented for the well. The well is one of 12 exploratory wells drilled in the north- central Oahu area between July 1993 and May 1994 in cooperation with the Honolulu Board of Water Supply.

  3. Drilling, construction, caliper-log, and specific-conductance data for well 3-3604-01, Kawailoa deep monitor well, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The Kawailoa deep monitor well (State well number 3-3604-01) was drilled about 1.9 miles east- northeast of the town of Haleiwa. The well is on agricultural land in the Kawailoa ground-water area. The well penetrates through the freshwater lens and into the freshwater-saltwater transition zone to an elevation of -392 feet below mean sea level. Well-construction data, logs of drilling notes, geologic descriptions for the samples, specific-conductance and caliper-log data are presented for the well. The well is one of 12 exploratory wells drilled in the north-central Oahu area between July 1993 and May 1994 in cooperation with the Honolulu Board of Water Supply.

  4. Brookian sequence well log correlation sections and occurrence of gas hydrates, north-central North Slope, Alaska

    USGS Publications Warehouse

    Lewis, Kristen A.; Collett, Timothy S.

    2013-01-01

    Gas hydrates are naturally occurring crystalline, ice-like substances that consist of natural gas molecules trapped in a solid-water lattice. Because of the compact nature of their structure, hydrates can effectively store large volumes of gas and, consequently, have been identified as a potential unconventional energy source. First recognized to exist geologically in the 1960s, significant accumulations of gas hydrate have been found throughout the world. Gas hydrate occurrence is limited to environments such as permafrost regions and subsea sediments because of the pressure and temperature conditions required for their formation and stability. Permafrost-associated gas hydrate accumulations have been discovered in many regions of the Arctic, including Russia, Canada, and the North Slope of Alaska. Gas hydrate research has a long history in northern Alaska. This research includes the drilling, coring, and well log evaluation of two gas hydrate stratigraphic test wells and two resource assessments of gas hydrates on the Alaska North Slope. Building upon these previous investigations, this report provides a summary of the pertinent well log, gas hydrate, and stratigraphic data for key wells related to gas hydrate occurrence in the north-central North Slope. The data are presented in nine well log correlation sections with 122 selected wells to provide a regional context for gas hydrate accumulations and the relation of the accumulations to key stratigraphic horizons and to the base of the ice-bearing permafrost. Also included is a well log database that lists the location, available well logs, depths, and other pertinent information for each of the wells on the correlation section.

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

    NASA Astrophysics Data System (ADS)

    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.

  6. A computer program for borehole compensation of dual-detector density well logs

    USGS Publications Warehouse

    Scott, James Henry

    1978-01-01

    The computer program described in this report was developed for applying a borehole-rugosity and mudcake compensation algorithm to dual-density logs using the following information: the water level in the drill hole, hole diameter (from a caliper log if available, or the nominal drill diameter if not), and the two gamma-ray count rate logs from the near and far detectors of the density probe. The equations that represent the compensation algorithm and the calibration of the two detectors (for converting countrate or density) were derived specifically for a probe manufactured by Comprobe Inc. (5.4 cm O.D. dual-density-caliper); they are not applicable to other probes. However, equivalent calibration and compensation equations can be empirically determined for any other similar two-detector density probes and substituted in the computer program listed in this report. * Use of brand names in this report does not necessarily constitute endorsement by the U.S. Geological Survey.

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

    USGS Publications Warehouse

    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.

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

    USGS Publications Warehouse

    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

  9. Geophysical Log Analysis of Selected Test Holes and Wells in the High Plains Aquifer, Central Platte River Basin, Nebraska

    USGS Publications Warehouse

    Anderson, J. Alton; Morin, Roger H.; Cannia, James C.; Williams, John H.

    2009-01-01

    The U.S. Geological Survey in cooperation with the Central Platte Natural Resources District is investigating the hydrostratigraphic framework of the High Plains aquifer in the Central Platte River basin. As part of this investigation, a comprehensive set of geophysical logs was collected from six test holes at three sites and analyzed to delineate the penetrated stratigraphic units and characterize their lithology and physical properties. Flow and fluid-property logs were collected from two wells at one of the sites and analyzed along with the other geophysical logs to determine the relative transmissivity of the High Plains aquifer units. The integrated log analysis indicated that the coarse-grained deposits of the alluvium and the upper part of the Ogallala Formation contributed more than 70 percent of the total transmissivity at this site. The lower part of the Ogallala with its moderately permeable sands and silts contributed some measureable transmissivity, as did the fine-grained sandstone of the underlying Arikaree Group, likely as a result of fractures and bedding-plane partings. Neither the lower nor the upper part of the siltstone- and claystone-dominated White River Group exhibited measurable transmissivity. The integrated analysis of the geophysical logs illustrated the utility of these methods in the detailed characterization of the hydrostratigraphy of the High Plains aquifer.

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

    USGS Publications Warehouse

    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.

  11. Drilling, construction, and caliper-log data for wells 3-3406-14 and -15, Helemano exploratory wells I and II, Oahu, Hawaii

    USGS Publications Warehouse

    Presley, T.K.; Oki, D.S.

    1996-01-01

    The Helemano exploratory wells I and II (State well numbers 3-3406-14 and -15) were drilled near Weed Circle, about 3,000 feet south of the town of Haleiwa. The wells are located on agricultural land in the Waialua ground-water area. The wells penetrate through sedimentary deposits (caprock) and into a basalt aquifer. Both wells have short open intervals cased with well screen at the bottom of the hole, and are cased and sealed through the caprock and basalt to the well screen. The shallow well, Helemano exploratory well I, penetrates about 10 feet into the basalt aquifer below the contact of the caprock and basalt. The deep well, Helemano exploratory well II, penetrates about 210 feet into the basalt aquifer. The deep well has a 20-foot open interval at the bottom. Well construction data, logs of drilling notes, geologic descriptions for drill samples, and caliper-log data are presented for the wells. The wells are two of twelve exploratory wells drilled in the north-central Oahu area between July 1993 and May 1994 in cooperation with the Honolulu Board of Water Supply.

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

    NASA Astrophysics Data System (ADS)

    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 <3 °C. The thermal-conductivity calculation allowed an evaluation of the depth range in which the palaeoclimatic 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.

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

    USGS Publications Warehouse

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

    2015-01-01

    The geophysical logs and their analyses are available for display and download from the U.S. Geological Survey, New York Water Science Center, online geophysical log archive (http://ny.water.usgs.gov/maps/geologs/) in LAS (Log ASCII Standard), PDF, and WellCad formats.

  14. Correlation of lithologic and sonic logs from the COST No. B-2 well with seismic reflection data

    USGS Publications Warehouse

    King, K.C.

    1979-01-01

    The purpose of this study was to correlate events recorded on seismic records with changes in lithology recorded from sample descriptions from the Continental Offshore Stratigraphic Test (COST) No. B-2 well.  The well is located on the U.S. mid-Atlantic Outer Continental Shelf about 146 km east of Atlantic City, N.J. (see location map).  Lithologic data are summarized from the sample descriptions of Smith and others (1976).  Sonic travel times were read at 0.15 m intervals in the well using a long-space sonic logging tool.  Interval velocities, reflection coefficients and a synthetic seismogram were calculated from the sonic log.

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

    USGS Publications Warehouse

    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. Well log and seismic character of tertiary terumbu carbonate, South China Sea, Indonesia

    SciTech Connect

    May, J.A.

    1985-09-01

    The Esso Exploration and Production Inc. Natuna DAlpha block lies approximately 125 mi (200 km) northeast of Natuna Island in the Indonesian portion of the South China Sea. The block contains a large Miocene platform carbonate complex called the L-structure. The Terumbu Formation L-structure, situated in front of and isolated from a much larger carbonate shelf, is similar to the carbonate atolls developed in front of the barrier-reef complex offshore of Belize. The lower platform and upper platform have a similar log character. The detrital facies is composed of fore-reef talus, pelagic, and hemipelagic carbonates. By mapping the Terumbu carbonate facies, the growth history of the L-structure is revealed.

  17. Sequence stratigraphy of the Jurassic: New data from the Paris-London basin compiled on well logs

    SciTech Connect

    Ponsot, C.M.; Vail, P.R. )

    1991-03-01

    A sequence stratigraphic analysis of the Jurassic sedimentary succession in Paris basin is derived from an integration of subsurface log correlations, field observations, and reinterpretations of field descriptions. The analysis is presented on two log sections, one crossing the basin from northeast to southwest and the other from northwest to southeast (approximately 80 logs). A vast quantity of field data, collected all around the Parsi basin (English Dorset, French Normandy, Manche, Ardennes, Lorraine, Bourgogne) allowed the sequences and system tracts boundaries to be traced and dated at the same time or prior to being recognized on well log data. In comparison with the Haq et al. 1987 cycle chart, 16 new sequences have been added: three for the Lias, seven for the Dogger, and six for the Malm. Occasionally, ages of some of the already recognized sequences boundaries have been slightly modified to fit new biostratal data. These biostratal data were usually at the scale of the ammonite sub-zone and the actual give ages all tie with the 1987 Haq et al. chart time scale.

  18. Geophysical logs and hydrologic data for eight wells in the Coyote Spring Valley area, Clark and Lincoln counties, Nevada

    USGS Publications Warehouse

    Berger, D.L.; Kilroy, K.C.; Schaefer, D.H.

    1988-01-01

    Geophysical logs, drilling operations, pump-test data, and water quality determinations are presented for eight wells in the Coyote Spring Valley area of southeastern Nevada. The wells are in an area where thick units of Paleozoic carbonate rock are overlain by Tertiary semiconsolidated basin-fill deposits and Quaternary alluvial deposits. Data collected by the U.S. Geological Survey were augmented with data from previous investigations; however, complete sets of logs and other data are not available for all eight wells. Geophysical data presented included natural-gamma, neutron, gamma-gamma density, caliper, temperature, acoustic, single-point resistance, long- and short-natural resistivity, and spontaneous-potential logs. Drilling penetration rates, lithologic columns, and well construction are also summarized and presented. Measurements of drawdown and recovery during and after constant-discharge pumping periods are also included. Also presented are results of chemical and physical analyses for major-ion chemistry, trace constituents, stable and radioactive isotopes, temperature, pH, specific conductance, and dissolved oxygen. (USGS)

  19. Paleosols: Their use in well log correlation and seismic stratigraphy in Cenozoic basin-fill, southwestern Montana

    SciTech Connect

    Hanneman, D.L. ); Wideman, C.J. . Dept. of Geophysical Engineering); Halvorson, J. )

    1992-01-01

    The use of paleosols as sequence boundary markers has recently been shown to be one of the most important tools for the interpretation of seismic data in regions of continental Cenozoic basin-fill material. Calcic paleosols and their defined sequence boundaries have been previously mapped on the surface and tied to seismic reflection data, and now can be delineated on well logs. Analyses of sonic and density logs from wells in the Deerlodge Valley, southwestern Montana, has resulted in the identification of several relatively thin, high velocity/high density zones which exist within the Cenozoic basin-fill. Zone thickness varies from 1 to 1.5 meters, and the zones are stacked up to as much as 40 meters. Density changes within the zones up to 0.6 g/cm[sup 3]. Velocity changes up to 1,660 meters/second. Well cutting chips from the high velocity/high density zones exhibit pedogenic features associated with calcic paleosols, such as clastic grains floating in micrite, grains corroded by calcite, and calcified root filaments. The authors generate synthetic seismograms from the sonic and density well logs which they analyze, and tie the seismograms to seismic reflection data using bright reflectors. The bright reflectors are interpreted as sequence boundaries on the seismic data and can be projected to the surface where they are associated with stacked zones of calcic paleosols which mark surface sequence boundaries.

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

    NASA Astrophysics Data System (ADS)

    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

  1. Methods and apparatus for measuring a length of cable suspending a well logging tool in a borehole

    SciTech Connect

    Broding, R.A.

    1986-07-01

    A system is described for measuring depth from the mouth of a borehole to a well logging tool connected to one end of an electrically conductive cable suspended in the borehole comprising: means for applying an initial electrical time pulse signal to one end of the cable, whereby the initial electrical time pulse signal propagates the length of the cable to one end of the cable to the well logging tool connected to the other end of the cable; means for detecting at the mouth of the borehole, which is intermediate both ends of the cable, the passage of the initial electrical time pulse signal along the length of the cable; means for detecting at the mouth of the borehole a subsequent electrical time pulse propagating along the length of the cable reflected from the other end of the cable; means for determining a time interval between the detection of the initial electrical time pulse signal at the mouth of the borehole and the detection of the subsequent electrical time pulse signal at the mouth of the borehole; and means for correlating the time interval with the depth to which the well logging tool is suspended in the borehole as measured from the mouth of the borehole.

  2. The Synthetic Convection Log - geophysical detection and identification of density-driven convection in monitoring wells and boreholes

    NASA Astrophysics Data System (ADS)

    Berthold, S.

    2009-12-01

    Detection and quantification of flow and transport is an important part of groundwater geophysics. A distinctive flow and transport problem occurs in boreholes and groundwater monitoring wells. They locally distort the natural flow field and open up an additional possibility of vertical heat and mass transfer between rock formations (e.g. aquifers), surrounding, and atmosphere. A variety of processes can cause a mass input or exchange through the fluid column. Density-driven convection (also called free convection or natural convection) plays an important role among them. Density-driven convective flows have adulterating effects on groundwater samples and in-situ measurements in monitoring wells and boreholes. Gases and other (dissolved) substances are possibly transported into new depths where varying chemical processes may arise. Consequently, knowing about the existence of vertical density-driven flows in fluid columns is crucial for hydrological investigations and for borehole geophysics. Moreover, temperatures in fluid columns and in the proximate formation may depart significantly from the ones in the surrounding rock when affected by vertical convection. Thus, understanding convective flow within the borehole is also important for subsurface water movement investigations and geothermics. The existence of significant vertical free convection was proven using pilot scale experiments and numerical modeling. However, so far, no particular logging device or interpretation algorithm was available that could detect free convection. Here an interpretation algorithm will be presented that approaches the problem. The so-called Synthetic Convection Log (SYNCO-Log) enables in-situ detection and even identification of free convective, including double-diffusive, flows using state-of-the-art geophysical borehole measurements like temperature and water conductivity/mud resistivity logs. In the sense of a "quick look" interpretation, the SYNCO-Log visually divides the fluid

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

    NASA Astrophysics Data System (ADS)

    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 <15% for thermal conductivity and thermal diffusivity, and of <10% for specific heat capacity. Comparison of predicted and benchmark laboratory thermal conductivity from deep boreholes of the Norwegian-Danish Basin, the North German Basin, and the Molasse Basin results in 3 to 5% larger uncertainties with regard to the test data set. With regard to temperature models, the use of calculated TC borehole profiles approximate measured temperature logs with an

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

    USGS Publications Warehouse

    Enomoto, Catherine B.

    2014-01-01

    The Wilcox Group is productive in updip areas of Texas and Louisiana from fluvial, deltaic, and near-shore marine shelf sandstones. The reported presence of porous sandstones at 29,000 feet within the Wilcox Group containing about 200 feet of gas in the Davy Jones 1 discovery well in the offshore Louisiana South Marsh Island area illustrates a sand-rich system developed during the Paleocene and early Eocene. This study describes some of the well log and reflection seismic data characteristics of the slope and basin-floor reservoirs with gas-discovery potential that may be in the area between the producing trend onshore Louisiana and the offshore discovery.

  5. Artificial neural networks to support petrographic classification of carbonate-siliciclastic rocks using well logs and textural information

    NASA Astrophysics Data System (ADS)

    Silva, Adrielle A.; Lima Neto, Irineu A.; Misságia, Roseane M.; Ceia, Marco A.; Carrasquilla, Abel G.; Archilha, Nathaly L.

    2015-06-01

    Petrographic class identification is of great importance to petroleum reservoir characterization and wellbore economic viability analysis, and is usually performed using core or geophysical log analysis. The coring process is costly, and well log analysis requires highly specific knowledge. Thus, great interest has arisen in new methods for predicting the lithological and textural properties of a wide area from a small number of samples. The artificial neural network (ANN) is a computational method based on human brain function and is efficient in recognizing previously trained patterns. This paper demonstrates petrographic classification of carbonate-siliciclastic rocks using a back-propagation neural network algorithm supported by elastic, mineralogical, and textural information from a well data set located in the South Provence Basin, in the southwest of France. The accuracy of the testing suggests that an ANN application offers an auxiliary tool for petrographic classification based on well data, specifically for prediction intervals in wells that have not been sampled or wells adjacent to sampled wells.

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

    SciTech Connect

    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.

  7. Comprehensive glacial sediment characterization and correlation with natural gamma log response to identify hydrostratigraphic units in a rotosonic well core

    NASA Astrophysics Data System (ADS)

    Frahm, A. L.; Lemke, L. D.

    2010-12-01

    Common borehole geophysical methods use electrical, acoustic, and nuclear measurements to determine physical and chemical characteristics of soils and rocks encountered while drilling. In texturally and mineralogically mature detrital sediments, natural gamma logs are frequently used to differentiate coarse and fine textures that exert primary control on fluid flow in reservoir and aquifer units. Interpretation of natural gamma log response in immature sediments can be complicated by the presence of clays in the fine fraction of poorly sorted units and further confounded in heterogeneous glacial sediments which characteristically display a high degree of vertical and lateral lithologic variability. This study examined natural gamma log response to textural and mineralogical variability in a continuous 70m (230ft) rotosonic borehole drilled through Pleistocene glacial sediments west of Ann Arbor, Michigan, USA. The objective of the investigation is to establish a statistical linkage between natural gamma radiation and glacial sediment texture that can be extrapolated to a set of more than 120 monitoring wells and used as soft conditioning information for stochastic simulations of aquifer characteristics across a 10 km2 area impacted by groundwater contamination. The core was sampled at 0.3m (1ft) intervals and sieved to quantify sediment texture at 225 points. 150 grain mount thin sections from samples selected to correspond to a distribution of low, moderate, and high natural gamma log readings.were point counted to quantify mineralogy of the sand size fraction. 30 samples of clay-sized particles taken from the decanted fine fraction of the sieved material were analyzed by X-ray diffraction for clay component analysis. Weak correlations of gamma response to measured characteristics were observed over the entire dataset. As expected, positive relationships with gamma response were observed in samples with higher K-feldspar content and greater proportions of fine

  8. Realtime logging

    SciTech Connect

    Whittaker, A.; Kashuba, M.J.

    1987-01-01

    This article reports that measurement-while-drilling (MWD) logging services have become an important new source of drilling and geological information on wildcats and some development wells. Sensors located within the bottomhole assembly, barely a few feet above the bit, make measurements on the formation, the borehole and the drill string itself. The MWD measurements are electronically processed and stored in the logging tool downhole. Simple MWD logging systems must wait until after tripping out of the hole for the MWD data to be downloaded from the logging tool to a surface computer in order for logs to be produced. This method is acceptable for some formation evaluation problems. But when well control, directional or completion decisions must be made, the benefit of MWD logging data is obtained only if the downhole measurements are available to the engineer in realtime.

  9. Closed-loop flow test Miravalles Geothermal Field well log results

    SciTech Connect

    Dennis, B.; Eden, G.; Lawton, R.

    1992-10-01

    The Instituto Costarricense de Electricidad (ICE) conducted a closed-loop flow test in the Miravalles Geothermal Field. The closed-loop test was started in May and ran through August of 1990. The effluent from the production well PG-11 was carried by a pipeline through a monitor station to the injection well PG-2. Before starting the long-term flow test in May, cold-water injection experiments were performed in each well to determine the pressure and temperature response. A series of downhole measurements were made in each well to obtain background information. The downhole measurements were repeated in August just before terminating the flow test to evaluate the results.

  10. Closed-loop flow test Miravalles Geothermal Field well log results

    SciTech Connect

    Dennis, B.; Eden, G.; Lawton, R.

    1992-01-01

    The Instituto Costarricense de Electricidad (ICE) conducted a closed-loop flow test in the Miravalles Geothermal Field. The closed-loop test was started in May and ran through August of 1990. The effluent from the production well PG-11 was carried by a pipeline through a monitor station to the injection well PG-2. Before starting the long-term flow test in May, cold-water injection experiments were performed in each well to determine the pressure and temperature response. A series of downhole measurements were made in each well to obtain background information. The downhole measurements were repeated in August just before terminating the flow test to evaluate the results.

  11. Analysis of sonic well logs applied to erosion estimates in the Bighorn Basin, Wyoming

    SciTech Connect

    Heasler, H.P.; Kharitonova, N.A.

    1996-05-01

    An improved exponential model of sonic transit time data as a function of depth takes into account the physical range of rock sonic velocities. In this way, the model is more geologically realistic for predicting compaction trends when compared to linear or simple exponential functions that fail at large depth intervals. The improved model is applied to the Bighorn basin of northwestern Wyoming for calculation of erosion amounts. This basin was chosen because of extensive geomorphic research that constrains erosion models and because of the importance of quantifying erosion amounts for basin analysis and hydrocarbon maturation prediction. Thirty-six wells were analyzed using the improved exponential model. Seven of these wells, due to limited data from the Tertiary section, were excluded from the basin erosion analysis. Erosion amounts from the remaining 29 wells ranged from 0 to 5600 ft (1700 m), with an average of 2500 ft (800 m).

  12. Alternative electronic logging technique locates fractures in Austin chalk horizontal well

    SciTech Connect

    Stang, C.W. )

    1989-11-01

    This article describes the search for a technique to locate fractures in a horizontal well. The author focuses on the utilization of a formation microscanner (FMS). The FMS is described and the results and problems associated with its utilization are presented.

  13. Movement of geothermal fluid in the Cerro Prieto field as determined from well log and reservoir engineering data

    SciTech Connect

    Halfman, S.E.; Lippmann, M.J.; Zelwer, R.

    1982-01-01

    A hydrogeologic model of the Cerro Prieto geothermal field in its undisturbed state, developed on the basis of well log and reservoir engineering data, is discussed. According to this model, geothermal fluid enters the field from the east through a deep (>10,000 ft) sandstone aquifer which is overlain by a thick shale unit which locally prevents the upward migration of the fluid. As it flows westward, the fluid gradually rises through faults and sandy gaps in the shale unit. Eventually, some of the fluid leaks to the surface in the western part of the field, while the rest mixes with surrounding colder waters.

  14. Well logging apparatus having a cylindrical housing with antennas formed in recesses and covered with a waterproof rubber layer

    SciTech Connect

    Clark, B.; Jundt, J.; Luling, M.; Ross, M.O.

    1990-08-14

    This paper discusses a well logging device for investigating formations surrounding a borehole. It comprises an elongated generally cylindrical housing moveable through the borehole; a transmitting antenna and first and second receiving antennas carried by the housing, the receiving antennas being successively spaced longitudinally from the transmitting antenna; first and second compartments in the housing; means for applying electromagnetic energy to the transmitting antenna; and means coupled to the signal conditioning means for receiving signals from the receiving antennas and for measuring the signals.

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

    NASA Astrophysics Data System (ADS)

    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.

  16. Assessment of seal quality for potential storage sites in the Norwegian North Sea from well log data

    NASA Astrophysics Data System (ADS)

    Angeli, M.; Gabrielsen, R. H.; Faleide, J. I.

    2012-04-01

    Fluid migration through caprocks is a crucial process when it comes to evaluate their sealing capacity for underground CO2 storage. Migration mechanisms such as flow through fault systems or along wells are quite easily identified by their relatively large size and because these features can be monitored by the use of reflection seismic data or well logs. However, microcracks in rocks, which can allegedly cause fluid migration through tight rocks, are difficult to detect from large scale observations and can only be deduced from thorough investigation. The objective of this work is to evaluate the likelihood of microfracture networks in potential seals (shales) through the analysis of well log data. This study focuses on the Upper Jurassic and Lower Cretaceous shale succession in the Norwegian North Sea. The main target of the study is the Draupne Formation (upper Jurassic) found in the Horda Platform / Viking Graben area. It has been deposited syn-rift during the second episode of the Viking graben formation in the Upper Jurassic, and thus has a burial depth ranging from 914 to 4573 m. This formation is identified in well logs by its sharp decrease in ultrasonic velocity and density, and specifically high resistivity and gamma ray readings. Other studied shale formations include the rest of the Viking Group (Heather Formation), the Tyne Group in the Central Graben (Farsund, Haugesund and Mandal) and the Boknfjord Group in the Norwegian-Danish Basin (Egersund, Flekkefjord, Sauda and Tau). Public well log data from 104 boreholes in the Norwegian sector of the North Sea have been analyzed and among them, 87 had a complete set of logs that are necessary for our analysis: ultrasonic velocities, gamma ray, density and resistivity. This study illustrates that the first-order variation of the ultrasonic velocity for the Draupne Formation in the Norwegian North Sea is of course due to depth. Diagenesis, whether mechanical or chemical, stiffens the rock by strengthening the

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

    NASA Astrophysics Data System (ADS)

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

    2014-05-01

    Background In order to increase access to drinking water in Africa there is more and more interest in the promotion of manual drilling techniques, without need of expensive drilling equipment, but they can be applied only in those areas with suitable hydrogeological conditions: thick layers of unconsolidated sediments and shallow groundwater level. Mapping of suitable zones for manual drilling at national level in Africa is a crucial activity and local institutions and UNICEF are implementing specific programs for its promotion, but the limitation in available data concerning shallow hydrogeological aquifers are limited. The research has been developed in the project "Use of remote sensing and terrain modeling to identify suitable zones for manual drilling in Africa and support low cost water supply", within the scientific cooperation between the University of Milano-Bicocca, Universite' Cheick Anta Diop (Dakar Senegal) , SNAPE - Service Nationale de Points d'Eau (Conakry Guinea), UNICEF Senegal and UNICEF Guinea. The project is funded by NERC (National Environmental Research Council, UK). Objective of the research: The presented work is only the starting point of the project aiming to elaborate an automatic procedures to manage and improve the existing database of borehole logs in Senegal and Guinea for the interpretation of shallow hydrogeological conditions and identification of suitable zones for manual drilling, in two pilot areas: Louga (Northwestern Senegal) and Faranah/Kankan (Eastern Guinea). Within the objective of the project is also considered the integration of Remote Sensing to support hydrogeological interpretation, especially where borehole logs are not present. Methodology Focus is to create a hydrogeological database, TANGAFRIC, to organize, codify and elaborate hydrogeological data. The metodology derives from the software TANGRAM (www.tangram.samit.unimib.it) produced by the University of Milano Bicocca, with innovative aspect of stratigraphic

  18. Analysis of Cretaceous (Aptian) strata in central Tunisia, using 2D seismic data and well logs

    NASA Astrophysics Data System (ADS)

    Zouaghi, Taher; Ferhi, Issam; Bédir, Mourad; Youssef, Mohamed Ben; Gasmi, Mohamed; Inoubli, Mohamed Hédi

    2011-08-01

    This paper presents a structural and depositional model of lower Cretaceous (Aptian) strata in central Tunisia, using detailed facies relations in outcrops, seismic reflection data, and wells. The study interval (called the "Aptian supersequence") is subdivided into four seismic sequences containing third-order sequences. Sequence architecture was strongly affected by syndepositional tectonic movements, which controlled sequence position and distribution. Specifically, the seismic sections show irregular distribution of different zones of subsidence and uplift. The observed structures identified through the detailed mapping suggest that lower Cretaceous rifting created depressions and grabens that filled with strata characterized by divergent reflectors striking against dipping growth faults. The Aptian-Albian unconformity ("crisis") marked a change of the extensional stress field from NNW-SSE to NE-SW induced rotation of blocks and an evolution of sedimentary basin filling related to the regional tectonic deformation. Local salt tectonic movement accentuated the formation of asymmetric depocenters. The salt ascended at the junction of master faults, resulting in cross-cutting of the strata and local reworking of Triassic evaporites in Aptian strata. Basinward to landward variations of the thickness and facies associated with strata pinch-outs and unconformities are related to the main synsedimentary tectonic events that were synchronous with salt tectonic movements. Triassic salt domes and salt intrusions along faults accentuated the border elevations between basin depocenters and uplifts. These sedimentary phenomena in central Tunisia are interpreted as causally related aspects of a local and global tectonic event during the Aptian.

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

    SciTech Connect

    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.

  20. Physical rock properties in and around a conduit zone by well-logging in the Unzen Scientific Drilling Project, Japan

    USGS Publications Warehouse

    Ikeda, R.; Kajiwara, T.; Omura, K.; Hickman, S.

    2008-01-01

    The objective of the Unzen Scientific Drilling Project (USDP) is not only to reveal the structure and eruption history of the Unzen volcano but also to clarify the ascent and degassing mechanisms of the magma conduit. Conduit drilling (USDP-4) was conducted in 2004, which targeted the magma conduit for the 1990-95 eruption. The total drilled length of USDP-4 was 1995.75??m. Geophysical well logging, including resistivity, gamma-ray, spontaneous potential, sonic-wave velocity, density, neutron porosity, and Fullbore Formation MicroImager (FMI), was conducted at each drilling stage. Variations in the physical properties of the rocks were revealed by the well-log data, which correlated with not only large-scale formation boundaries but also small-scale changes in lithology. Such variations were evident in the lava dike, pyroclastic rocks, and breccias over depth intervals ranging from 1 to 40??m. These data support previous models for structure of the lava conduit, in that they indicate the existence of alternating layers of high-resistivity and high P-wave velocity rocks corresponding to the lava dikes, in proximity to narrower zones exhibiting high porosity, low resistivity, and low P-wave velocity. These narrow, low-porosity zones are presumably higher in permeability than the adjacent rocks and may form preferential conduits for degassing during magma ascent. ?? 2008 Elsevier B.V.

  1. Locations and monitoring well completion logs of wells surveyed by U.S. Geological Survey at Air Force Plant 4 and Naval Air Station, Joint Reserve Base, Carswell Field, Fort Worth area, Texas

    USGS Publications Warehouse

    Williams, M.D.; Kuniansky, E.L.

    1996-01-01

    Completion logs are presented for 16 monitoring wells installed by the U.S. Geological Survey at Air Force Plant 4 and Naval Air Station, Joint Reserve Base, Carswell Field, in the Fort Worth area, Texas. Natural gamma-ray logs are presented for selected monitoring wells. Also included are survey data for eight wells installed by Geo-Marine, Inc.

  2. Reviews Equipment: Data logger Book: Imagined Worlds Equipment: Mini data loggers Equipment: PICAXE-18M2 data logger Books: Engineering: A Very Short Introduction and To Engineer Is Human Book: Soap, Science, & Flat-Screen TVs Equipment: uLog and SensorLab Web Watch

    NASA Astrophysics Data System (ADS)

    2012-07-01

    WE RECOMMEND Data logger Fourier NOVA LINK: data logging and analysis To Engineer is Human Engineering: essays and insights Soap, Science, & Flat-Screen TVs People, politics, business and science overlap uLog sensors and sensor adapter A new addition to the LogIT range offers simplicity and ease of use WORTH A LOOK Imagined Worlds Socio-scientific predictions for the future Mini light data logger and mini temperature data logger Small-scale equipment for schools SensorLab Plus LogIT's supporting software, with extra features HANDLE WITH CARE CAXE110P PICAXE-18M2 data logger Data logger 'on view' but disappoints Engineering: A Very Short Introduction A broad-brush treatment fails to satisfy WEB WATCH Two very different websites for students: advanced physics questions answered and a more general BBC science resource

  3. Geophysical, stratigraphic, and flow-zone logs of selected test, monitor, and water-supply wells in Cayuga County, New York

    USGS Publications Warehouse

    Anderson, J. Alton; Williams, John H.; Eckhardt, David A.V.; Miller, Todd S.

    2003-01-01

    Volatile-organic compounds have been detected in water sampled from more than 50 supply wells between the City of Auburn and Village of Union Springs in Cayuga County, New York, and the area was declared a Superfund site in 2002. In 2001-04, geophysical logs were collected from 37 test, monitor, and water-supply wells as a preliminary part of the investigation of volatile-organic compound contamination in the carbonate-bedrock aquifer system. The geophysical logs included gamma, induction, caliper, wellbore image, deviation, fluid resistivity and temperature, and flowmeter. The geophysical logs were analyzed along with core samples and outcrops of the bedrock to define the stratigraphic units and flow zones penetrated by the wells. This report describes the logging methods used in the study and presents the geophysical, stratigraphic, and flow-zone logs.

  4. Assessing spatial uncertainty in reservoir characterization for carbon sequestration planning using public well-log data: A case study

    USGS Publications Warehouse

    Venteris, E.R.; Carter, K.M.

    2009-01-01

    Mapping and characterization of potential geologic reservoirs are key components in planning carbon dioxide (CO2) injection projects. The geometry of target and confining layers is vital to ensure that the injected CO2 remains in a supercritical state and is confined to the target layer. Also, maps of injection volume (porosity) are necessary to estimate sequestration capacity at undrilled locations. Our study uses publicly filed geophysical logs and geostatistical modeling methods to investigate the reliability of spatial prediction for oil and gas plays in the Medina Group (sandstone and shale facies) in northwestern Pennsylvania. Specifically, the modeling focused on two targets: the Grimsby Formation and Whirlpool Sandstone. For each layer, thousands of data points were available to model structure and thickness but only hundreds were available to support volumetric modeling because of the rarity of density-porosity logs in the public records. Geostatistical analysis based on this data resulted in accurate structure models, less accurate isopach models, and inconsistent models of pore volume. Of the two layers studied, only the Whirlpool Sandstone data provided for a useful spatial model of pore volume. Where reliable models for spatial prediction are absent, the best predictor available for unsampled locations is the mean value of the data, and potential sequestration sites should be planned as close as possible to existing wells with volumetric data. ?? 2009. The American Association of Petroleum Geologists/Division of Environmental Geosciences. All rights reserved.

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

    NASA Astrophysics Data System (ADS)

    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

  6. MS-BWME: A Wireless Real-Time Monitoring System for Brine Well Mining Equipment

    PubMed Central

    Xiao, Xinqing; Zhu, Tianyu; Qi, Lin; Moga, Liliana Mihaela; Zhang, Xiaoshuan

    2014-01-01

    This paper describes a wireless real-time monitoring system (MS-BWME) to monitor the running state of pumps equipment in brine well mining and prevent potential failures that may produce unexpected interruptions with severe consequences. MS-BWME consists of two units: the ZigBee Wireless Sensors Network (WSN) unit and the real-time remote monitoring unit. MS-BWME was implemented and tested in sampled brine wells mining in Qinghai Province and four kinds of indicators were selected to evaluate the performance of the MS-BWME, i.e., sensor calibration, the system's real-time data reception, Received Signal Strength Indicator (RSSI) and sensor node lifetime. The results show that MS-BWME can accurately judge the running state of the pump equipment by acquiring and transmitting the real-time voltage and electric current data of the equipment from the spot and provide real-time decision support aid to help workers overhaul the equipment in a timely manner and resolve failures that might produce unexpected production down-time. The MS-BWME can also be extended to a wide range of equipment monitoring applications. PMID:25340455

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

    NASA Astrophysics Data System (ADS)

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

    NASA Astrophysics Data System (ADS)

    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.

  9. Review of surface-equipment requirements for geothermal-well stimulation. Geothermal-reservoir well-stimulation program

    SciTech Connect

    Not Available

    1982-02-01

    A summary of stimulation equipment available to geothermal industry is presented and some modifications from which it could benefit are discussed. Equipment requirements for hydraulic fracturing, acid fracturing, acidizing, and other chemical treatments are included. Designs for the following are reviewed: equipment for premixing and storing treatment fluids, proppant handling equipment, pump trucks, special equipment for foam fracturing, intensifier pumps, manifolding, and monitoring and control devices.

  10. Completion reports, core logs, and hydrogeologic data from wells and piezometers in Prospect Gulch, San Juan County, Colorado

    USGS Publications Warehouse

    Johnson, Raymond H.; Yager, Douglas B.

    2006-01-01

    In the late nineteenth century, San Juan County, Colorado, was the center of a metal mining boom in the San Juan Mountains. Although most mining activity ceased by the 1990s, the effects of historical mining continue to contribute metals to ground water and surface water. Previous research by the U.S. Geological Survey identified ground-water discharge as a significant pathway for the loading of metals to surface water from both acid-mine drainage and acid-rock drainage. In an effort to understand the ground-water flow system in the upper Animas River watershed, Prospect Gulch was selected for further study because of the amount of previous data provided in and around that particular watershed. In support of this ground-water research effort, wells and piezometers were installed to allow for coring during installation, subsurface hydrologic testing, and the monitoring of ground-water hydraulic heads and geochemistry. This report summarizes the data that were collected during and after the installation of these wells and piezometers and includes (1) subsurface completion details, (2) locations and elevations, (3) geologic logs and elemental data, (4) slug test data for the estimation of subsurface hydraulic conductives, and (5) hydraulic head data.

  11. An integrated petrophysical approach to the sub-basalt imaging problem using well logging data to link measurements from cores and seismic experiments

    NASA Astrophysics Data System (ADS)

    Waagstein, R.; Boldreel, L. O.; Andersen, C.

    2003-04-01

    Flood basalt covered basins exist world wide along continental margins and are increasingly coming into the focus of the hydrocarbon industry as more accessible fields are being depleted. However, it has proved difficult in many places to look through the basalt cover by conventional seismic reflection methods. This stresses the need for a better understanding of the acoustic properties of basalt. The Seismic Faroes Basalt Project (SeiFaBa) was established in 2002 as an integrated study of the sub-basalt image problem. It involves 9 scientific institutions and individuals and is funded collectively by all oil companies operating in the Faroes sector (the Sindri group). The planned fieldwork includes core drilling, wire-line logging, multi-azimuth VSP and surface seismic experiments at land and sea. It is mainly centred around Glyvursnes, a relatively flat promontory near Tórshavn that allows optimal layout of seismic lines and integration of core, log and seismic data. We present the initial task of drilling and logging, which was performed in Oct.-Nov. 2002. A 700 m slim borehole was drilled on the shore of Glyvursnes with wire-line coring technique and an old 660 m borehole (Vestmanna-1) 30 km farther northwest partly blocked by calcite fillings was reopened using the same equipment. An extensive wire-line logging program was subsequently run in both holes. These two holes, together with the existing 3.65-km Lopra-1/1A hole in the southernmost island Suduroy, cover all three Faroes basalt formations and a range of lava compositions and morphologies. We show examples of the correlation of lava flow sequences and wire-logging measurements. Detailed analysis of the new logs is being planned together with laboratory studies of the petrography, rock chemistry and petrophysical properties of core samples with the aim of establishing a log stratigraphy and scale core data to seismic scales.

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

    USGS Publications Warehouse

    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. Artificial Neural Networks applied to estimate permeability, porosity and intrinsic attenuation using seismic attributes and well-log data

    NASA Astrophysics Data System (ADS)

    Iturrarán-Viveros, Ursula; Parra, Jorge O.

    2014-08-01

    Permeability and porosity are two fundamental reservoir properties which relate to the amount of fluid contained in a reservoir and its ability to flow. The intrinsic attenuation is another important parameter since it is related to porosity, permeability, oil and gas saturation and these parameters significantly affect the seismic signature of a reservoir. We apply Artificial Neural Network (ANN) models to predict permeability (k) and porosity (ϕ) for a carbonate aquifer in southeastern Florida and to predict intrinsic attenuation (1/Q) for a sand-shale oil reservoir in northeast Texas. In this study, the Gamma test (a revolutionary estimator of the noise in a data set) has been used as a mathematically non-parametric nonlinear smooth modeling tool to choose the best input combination of seismic attributes to estimate k and ϕ, and the best combination of well-logs to estimate 1/Q. This saves time during the construction and training of ANN models and also sets a lower bound for the mean squared error to prevent over-training. The Neural Network method successfully delineates a highly permeable zone that corresponds to a high water production in the aquifer. The Gamma test found nonlinear relations that were not visible to linear regression allowing us to generalize the ANN estimations of k, ϕ and 1/Q for their respective sets of patterns that were not used during the learning phase.

  14. Predicting injection related changes in seismic properties at Kevin Dome, north central Montana, using well logs and laboratory measurements

    NASA Astrophysics Data System (ADS)

    Saltiel, S.; Bonner, B. P.; Ajo Franklin, J. B.

    2014-12-01

    Time-lapse seismic monitoring (4D) is currently the primary technique available for tracking sequestered CO2 in a geologic storage reservoir away from monitoring wells. The main seismic responses to injection are those due to direct fluid substitution, changes in differential pressure, and chemical interactions with reservoir rocks; the importance of each depends on reservoir/injection properties and temporal/spatial scales of interest. As part of the Big Sky Carbon Sequestration Partnership, we are monitoring the upcoming large scale (1 million ton+) CO2 injection in Kevin Dome, north central Montana. As part of this research, we predict the relative significance of these three effects, as an aid in design of field surveys. Analysis is undertaken using existing open-hole well log data and cores from wells drilled at producer and injector pads as well as core experiments. For this demonstration site, CO2 will be produced from a natural reservoir and re-injected down dip, where the formation is saturated with brine. Effective medium models based on borehole seismic velocity measurements predict relatively small effects (less than 40 m/s change in V¬p) due to the injection of more compressible supercritical CO2. This is due to the stiff dolomite reservoir rock, with high seismic velocities (Vp~6000 m/s, Vs~3000 m/s) and fairly low porosity (<10%). Assuming pure dolomite mineralogy, these models predict a slight increase in Vp during CO2 injection. This velocity increase is due to the lower density of CO2 relative to brine; which outweighs the small change in modulus compared to the stiff reservoir rock. We present both room pressure and in-situ P/T ultrasonic experiments using core samples obtained from the reservoir; such measurements are undertaken to access the expected seismic velocities under pressurized injection. The reservoir appears to have fairly low permeability. Large-volume injection is expected to produce large local pore pressure increases, which may

  15. Using Oil and Gas Well Log Records to Understand Possible Connections Between Wastewater Injection Zones and Usable Groundwater Aquifers in California

    NASA Astrophysics Data System (ADS)

    Shimabukuro, D.; Haugen, E. A.; Battistella, C.; Treguboff, E. W.; Kale, J. M.

    2015-12-01

    Although the disposal of produced water in wastewater injection wells has been occurring in California for decades, it is not clear whether injected fluids may be migrating into usable groundwater aquifers. One problem is the poor characterization of federally-protected (<10,000 ppm TDS) water in the state. Another is the lack of publically-accessible information about the hydrological properties of confining strata adjacent to injection zones. In effort to better understand these two problems, we have begun studying the archived oil and gas well records collected by the California Division of Oil, Gas, and Geothermal Resources (DOGGR). These scanned records contain two useful sources of information. First, geophysical well logs, such those measuring resistivity and porosity, can be used to determine aquifer salinity. This allows a three-dimensional understanding of the distribution of protected groundwater. Second, driller's logs contain lithological descriptions at depth. These lithologies can be used to construct a three-dimensional texture model, which can then be used in a groundwater flow model. A large number of undergraduate researchers at CSU Sacramento and CSU Long Beach have been collecting information on well records in the Ventura Basin and the Southern San Joaquin Valley. Each well record is examined with basic metadata entered into an online database in an effort to identify appropriate geophysical well logs and driller's logs. High-quality driller's logs are coded and used to create three-dimensional framework models for each well field. The geophysical logs are digitized and will be used to determine aquifer salinity. In addition, we are using information from the DOGGR well records to investigate wellbore integrity, waste disposal and waterflood injection volumes, and the possibility of induced seismicity. This project is part of the broader effort of the California State Water Resources Control Board to implement Senate Bill 4.

  16. Geophysical logging to determine construction, contributing zones, and appropriate use of water levels measured in confined-aquifer network wells, San Luis Valley, Colorado, 1998-2000

    USGS Publications Warehouse

    Brendle, D.L.

    2002-01-01

    Geophysical logs were recorded in 32 wells in the confined-aquifer monitoring well network maintained by the Rio Grande Water Conservation District. Logging results were used to determine well construction, zones contributing water to the wells, and the purposes for which the ground-water levels measured in the wells can be used. The confined-aquifer well network consists of 42 flowing and nonflowing wells. This network consists of wells used to supply water for irrigation, household use, wildlife refuge supply, and stock use, and wells for water-level monitoring. Geophysical logs recorded in the wells included video, caliper, water specific conductance, water temperature, and water flow. Most wells in the confined-aquifer well network yield a composite water level representing water levels in multiple permeable zones in the confined-aquifer system of the San Luis Valley. A potentiometric-surface map constructed using November 2000 water levels indicates that water levels from most wells in the network are correlated with water levels from nearby network wells. Potentiometric-surface maps that are constructed from water levels measured in most of the wells in the network can be used to understand long-term local and regional changes in water levels in the confined-aquifer system. Water levels measured in 8 of the 42 wells in the confined-aquifer network are not representative of water levels in the confined-aquifer system.

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

    NASA Astrophysics Data System (ADS)

    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

    NASA Astrophysics Data System (ADS)

    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. Miravalles Geothermal Project: Portable Well Flow Test Equipment and Procedures Manual

    SciTech Connect

    1980-05-01

    The well flow test program has been designed to facilitate the gathering of information, with portable test equipment, from various wells with regard to their capability of flow, the quality of steam produced at various back pressures, the composition and quantity of noncondensable gases flashed from the wells and the composition and quantity of solids in the well's liquid streams (brine). The test program includes procedures for obtaining the following basic flow data pertinent to the plant power cycle design: (1) Effluent steam and brine flows, pressures and temperatures; (2) Noncondensable and dissolved gas contents in steam and brine; (3) H{sub s}S content in gases formed; and (4) Solids content and chemical analysis of steam and brine.

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

    NASA Astrophysics Data System (ADS)

    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

  1. Records of wells, drillers' logs, water-level measurements, and chemical analyses of ground water in Brazoria, Fort Bend, and Waller counties, Texas, 1985-89

    USGS Publications Warehouse

    Locke, Glenn L.

    1991-01-01

    Data for water wells and ground water in Brazoria, Fort Bend, and Waller Counties were collected during 1985-89 by the U.S. Geological Survey. This report presents a compilation of records for 32 wells in Brazoria County, 19 wells in Fort Bend County, and 16 wells in Waller County. Drillers' logs for 65 wells, water levels for 85 wells, chemical analyses of water for 9 wells, and water levels and chemical analyses of water from previously inventoried wells also are presented in this report.

  2. Records of wells, drillers' logs, water-level measurements, and chemical analyses of ground water in Chambers, Liberty, and Montgomery counties, Texas, 1985-89

    USGS Publications Warehouse

    Locke, Glenn L.

    1991-01-01

    Data for water wells and ground water in Chambers, Liberty, and Montgomery Counties were collected during 1985-89 by the U.S. Geological Survey. This report presents a compilation of records for 4 wells in Chambers County, 8 wells in Liberty County, and 64 wells in Montgomery County. Drillers' logs of 60 wells, water levels for 84 wells, chemical analyses of water for 11 wells, and water levels and chemical analyses of water from previously inventoried wells also are presented in this report.

  3. Thin-walled liner equipment cuts costs on well deepening project

    SciTech Connect

    Sutherland, J.; Weaver, C.; Aiello, P.

    1996-08-26

    Thin-walled, slim hole liner equipment can save $3--4 million per well in deep reentry applications by allowing existing wells to be deepened or sidetracked rather than drilling new wells from surface. The design makes it possible to reenter existing wells, successfully isolate depleted zones, and deepen the well into virgin-pressured reservoirs. The design includes thin-walled, close-tolerance liner hangers, liner top packers, tieback seal assemblies, and liner setting sleeves that provide reasonable burst and collapse resistance while maintaining an inside diameter to facilitate drilling a deep, deviated 4 3/4 in. hole with a tapered 2 7/8 in. x 3 1/2 in. drillstring. In Shell Canada`s Waterton field, gas-producing wells originally drilled in the 1950s, 1960s, and 1970s to depths of 14,760 ft were completed with perforations in 7 in. casing and open hole. These wells are now being reentered to tap new reserves. The reentries encounter particularly challenging sour gas, low temperature, diverse formation pressure conditions. The objective of the reentry program is to seal off the depleted bottom zones of the wells and tap into the same fault-repeated formations ar virgin pressure, at a deeper level.

  4. 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

    USGS Publications Warehouse

    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.

  5. Well-log signatures of alluvial-lacustrine reservoirs and source rocks, Lagoa-Feia Formations, Lower Cretaceous, Campos Basin, offshore Brazil

    SciTech Connect

    Abrahao, D.; Warme, J.E.

    1988-01-01

    The Campos basin is situated in offshore southeastern Brazil. The Lagoa Feia is the basal formation in the stratigraphic sequence of the basin, and was deposited during rifting in an evolving complex of lakes of different sizes and chemical characteristics, overlying and closely associated with rift volcanism. The stratigraphic sequence is dominated by lacustrine limestones and shales (some of them organic-rich), and volcaniclastic conglomerates deposited on alluvial fans. The sequence is capped by marine evaporites. In the Lagoa Feia Formation, complex lithologies make reservoirs and source rocks unsuitable for conventional well-log interpretation. To solve this problem, cores were studied and the observed characteristics related to log responses. The results have been extended through the entire basin for other wells where those facies were not cored. The reservoir facies in the Lagoa Feia Formation are restricted to levels of pure pelecypod shells (''coquinas''). Resistivity, sonic, neutron, density, and gamma-ray logs were used in this work to show how petrophysical properties are derived for the unconventional reservoirs existing in this formation. The same suite of logs was used to develop methods to define geochemical characteristics where source rock data are sparse in the organic-rich lacustrine shales of the Lagoa Feia Formation. These shales are the main source rocks for all the oil discovered to date in the Campos basin.

  6. Records of wells, drillers' logs, water-level measurements, and chemical analyses of ground water in Harris and Galveston counties, Texas, 1980-84

    USGS Publications Warehouse

    Williams, James F.; Coplin, L.S.; Ranzau, C.E.; Lind, W.B.; Bonnet, C.W.; Locke, Glenn L.

    1987-01-01

    Information on major new water wells in Harris and Galveston Counties was compiled by the U.S. Geological Survey from 1980 to 1984. This report presents the results of the hydro!ogic data collection on new large-capacity and other selected wells, including well location and completion data, drillers 1 logs of the strata penetrated, water levels, and chemical quality of the produced water. These water-well data are supplementary to similar data on older wells in these counties and to descriptive evaluations of the ground-water resources which have been published previously.

  7. Lithologic properties of carbonate-rock aquifers at five test wells in the Coyote Spring Valley Area, southern Nevada, as determined from geophysical logs. Water resources investigation report

    SciTech Connect

    Berger, D.L.

    1992-01-01

    Regional ground-water flow systems in the carbonate-rock aquifers in southern Nevada were evaluated as potential sources for water supply as part of the Nevada Carbonate Aquifers Program. Geophysical log analyses indicated that the test wells penetrate carbonate rocks, which vary in composition from limestone to dolomite and include mixtures of both. Calcite was found to be the predominant matrix mineral and shales made up of only a small percentage of the overall rock. Bulk-density measurements averaged 2.65 grams per cubic centimeter and the matrix density estimates averaged 2.76 grams per cubic centimeter. Increased amounts of silica in the matrix mineralogy were associated with greater total porosity values. The log analyses indicated an average of 4.7 percent porosity for 43 zones in the test wells.

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

    NASA Astrophysics Data System (ADS)

    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

  9. Equipment

    NASA Astrophysics Data System (ADS)

    Szumski, Michał

    This chapter describes the most important features of capillary electrophoretic equipment. A presentation of the important developments in high voltage power supplies for chip CE is followed by preparation of fused silica capillaries for use in CE. Detection systems that are used in capillary electrophoresis are widely described. Here, UV-Vis absorbance measurements are discussed including different types of detection cells—also those less popular (u-shaped, Z-shaped, mirror-coated). Fluorescence detection and laser-induced fluorescence detection are the most sensitive detection systems. Several LIF setups, such as collinear, orthogonal, confocal, and sheath-flow cuvette, are presented from the point of view of the sensitivity they can provide. Several electrochemical detectors for CE, such as conductivity, amperometric, and potentiometric, are also shown and their constructions discussed. CE-MS and much less known CE (CEC)-NMR systems are also described. The examples of automation and robotized CE systems together with their potential fields of application are also presented.

  10. Power-law scaling of spatially correlated porosity and log(permeability) sequences from north-central North Sea Brae oilfield well core

    NASA Astrophysics Data System (ADS)

    Leary, P. C.; Al-Kindy, F.

    2002-03-01

    The spatial cross-correlation and power spectra of porosity and log(permeability) sequences are analysed for a total of 750 m of reservoir rock drill-core from four vertical wells in the Brae Formation, an important coarse-grained clastic North Sea hydrocarbon reservoir rock. The well core sequences are 80+/-4 per cent cross-correlated at zero lag and have power-law-scaling spatial power spectra S (k )~1/k β , β ~ 1+/-0.4, for spatial frequencies 5km-1 log(permeability) and the systematic power-law scaling of log(permeability) spatial fluctuation spectra fit into a broad physical context of (1) the 1/k spectral scaling observed in several hundred well logs of sedimentary and crystalline rock recorded world-wide; (2) the 1/f spectral scaling of temporal sequences in a wide range of physical systems; and (3) analogy with power-law-scaling spatial fluctuation spectra in a wide range of critical-state thermodynamic systems. In this physical context, the spatial fluctuations of log(permeability) of clastic reservoir rock are interpreted as due to long-range correlated random fracture-permeability networks in a fluid-saturated granular medium where the range ξ of spatial correlation is effectively infinite. Fracture-permeability spatial fluctuations with long-range correlations and 1/k -scaling spectra have practical implications for geofluid reservoir management. Inadequate models of reservoir flow structure are widely attributed to uncertainty in fault and fracture location and connectivity. As a general phenomenon, spatial configurations of large-amplitude, long-range spatially correlated random fluctuations are unpredictable from the statistics of small-scale samples. The observed 1/k spectral scaling of porosity and log(permeability) distributions thus implies that large-scale, large-amplitude fracture-related flow heterogeneity (1) can determine the drainage pattern of crustal reservoirs but (2

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

    SciTech Connect

    Prettyman, T.H.; Gardner, R.P.; Verghese, K. . 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. Results of borehole geophysical logging and hydraulic tests conducted in Area D supply wells, former US Naval Air Warfare Center, Warminster, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.; Grazul, Kevin E.

    1998-01-01

    Borehole geophysical logging, aquifer tests, and aquifer-isolation (packer) tests were conducted in four supply wells at the former U.S. Naval Air Warfare Center (NAWC) in Warminster, PA to identify the depth and yield of water-bearing zones, occurrence of borehole flow, and effect of pumping on nearby wells. The study was conducted as part of an ongoing evaluation of ground-water contamination at the NAWC. Caliper, natural-gamma, single-point resistance, fluid resistivity, and fluid temperature logs and borehole television surveys were run in the supply wells, which range in depth from 242 to 560 ft (feet). Acoustic borehole televiewer and borehole deviation logs were run in two of the wells. The direction and rate of borehole-fluid movement under non-pumping conditions were measured with a high-resolution heatpulse flowmeter. The logs were used to locate water-bearing fractures, determine probable zones of vertical borehole-fluid movement, and determine the depth to set packers. An aquifer test was conducted in each well to determine open-hole specific capacity and the effect of pumping the open borehole on water levels in nearby wells. Specific capacities ranged from 0.21 to 1.7 (gal/min)/ft (gallons per minute per foot) of drawdown. Aquifer-isolation tests were conducted in each well to determine depth-discrete specific capacities and to determine the effect of pumping an individual fracture or fracture zone on water levels in nearby wells. Specific capacities of individual fractures and fracture zones ranged from 0 to 2.3 (gal/min)/ft. Most fractures identified as water-producing or water-receiving zones by borehole geophysical methods produced water when isolated and pumped. All hydrologically active fractures below 250 ft below land surface were identified as water-receiving zones and produced little water when isolated and pumped. In the two wells greater then 540 ft deep, downward borehole flow to the deep water-receiving fractures is caused by a large

  13. 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

    USGS Publications Warehouse

    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.

  14. Study effects of geopressured-geothermal subsurface environment on elastic properties of Texas Gulf Coast sandstones and shales using well logs, core data, and velocity surveys. Final report

    SciTech Connect

    Gregory, A.R.

    1980-05-01

    Relations between porosity and permeability for the Pleasant Bayou wells were determined from conventional core data. Porosities from the time average equations required compaction correction factors of 1.9 in hydropressured sandstones and 1.0 in geopressured sandstones. Best average prmeabilities in the geopressured zone were found in the primary production interval 14,687 to 14,716 ft (4477 to 4485 m). Average density gradients were 2.106 x 10/sup -3/ and 2.688 x 10/sup -3/ (gm/cm/sup 3/)/100 ft in sandstones and shales respectively. Compressional (P-wave) and shear (S-wave) velocities from the long-spaced sonic log and bulk densities from the formation density log were used to compute in-situ elastic moduli, Poisson's ratio, V/sub p//V/sub s/, and bulk compressibility in two intervals of deep geopressured sandstone and shale in No. 2 Pleasant Bayou. Most computed values of these parameters seem reasonable. Improved accuracy of travel times from the long-spaced sonic log should permit more accurate depth-to-time correlation with seismic data.

  15. Map showing the depth to the base of the deepest ice-bearing permafrost as determined from well logs, North Slope, Alaska

    USGS Publications Warehouse

    Collett, T.S.; Bird, K.J.; Kvenvolden, K.A.; Magoon, L.B.

    1989-01-01

    Because gas hydrates from within a limited temperature range, subsurface equilibrium temperature data are necessary to calculate the depth and thickness of the gas-hydrate stability field.  Acquiring these data is difficult because drilling activity often disrupts equilibrium temperatures in the subsurface, and a well mush lie undisturbed until thermal equilibrium is reestablished (Lachenbruch and Brewer, 1959).  On the North Slope if Akaska, a series of 46 oil and gas exploratory wells, which were considered to be near thermal equilibrium (Lachenbruch and others, 1982; 1987), were surveyed with high-resolution temperature devices (see table 1).  However, several thousand other exploratory and production wells have been drilled on the North Slope, and although they do not include temperature profiles, their geophysical logs often allow descrimination between ice-bearing and non-ice-bearing strata.  At the outset of this study, the coincidence of the base of ice-bearing strata being near the same depth as the 0°C isotherm at Prudhoe Bay (Lachenbruch and others, 1982) appeared to offer an opportunity to quickly and inexpensively expand the size of our subsurface temperature data base merely by using well logs to identify the base of the ice-bearing strata.

  16. 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

    SciTech Connect

    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.

  17. 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

    USGS Publications Warehouse

    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

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

    USGS Publications Warehouse

    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

  19. Estimation of biogenic silica contents in marine sediments using seismic and well log data: Sediment Drift 7, Antarctica

    NASA Astrophysics Data System (ADS)

    Neagu, R. C.; Tinivella, U.; Volpi, V.; Rebesco, M.; Camerlenghi, A.

    2009-06-01

    Petrophysical properties (wet bulk density, porosity, P-wave velocity) are used to predict biogenic silica contents along a seismic reflection profile that ties two well sites, 1095 and 1096, drilled by Ocean Drilling Program (ODP) Leg 178 on sediment drifts on the Pacific continental margin of the Antarctic Peninsula. The biogenic silica contents along the seismic reflection profile were estimated on the basis of three hypotheses about petrophysical properties distributions in the two boreholes and statistical relationships between biogenic silica and other petrophysical properties, which were established on various sediment layers within the boreholes. Our study demonstrates the possibility to reliably predict the distribution of biogenic silica in the sub-seabed sediments if seismic data processed with amplitude preservation are used and statistical relations are considered. We conclude that the statistical extrapolation of biogenic silica content along seismic reflection profiles tied to borehole data is an efficient tool to quantify the amounts of silica undergoing crystalline transformation, which may have strong implications for submarine slope destabilisation.

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

    USGS Publications Warehouse

    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 <50??C/km at their bottom. The maximum 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

  1. 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.

    NASA Astrophysics Data System (ADS)

    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

  2. Method for interpreting well log records to yield indications of gas/oil in an earth formation such as a sandstone, limestone, or dolostone

    SciTech Connect

    Thompson, D.D.; Brown, R.J.S.; Runge, R.J.

    1983-08-16

    The present invention indicates that acoustic characteristics associated with a first well penetration a gas/oil-containing strata such as a sandstone, limestone or dolostone, can be normalized (and favorably compared) with similar characteristics of a second, contiguous well of known hydrocarbon potential, such characteristics being calculated and displayed by means of a machine-implemented data processing method in which well logging and geologic data are fed thereto to calculate such characteristics without the need for shear-wave velocities. In more detail, in accordance with the invention brine-saturated bulk and shear moduli, (i.e., Kw and Gw) of a sandstone, limestone or dolostone penetrated by the second well can be predicted as a funtions of, say, brine-saturated P-wave modulus (PW *) alone (independent of shear-wave velocity). In that way, resulting acoustic values including distinct velocity and amplitude values as a function of a saturation operator can ultimately be provided. Such values, when compared to actual, in-well, field-generated characteristics of the first well, are surprisingly accurate predictors of the amount of gas/oil maturation in and around the first well. The method has particular accuracy in designating gas zones within formations of interest due to use of the complete Benedict-Webb-Rubin non-ideal gas law in pseudo-reduced form.

  3. Water-level, borehole geophysical log, and water-quality data from wells transecting the freshwater/saline-water interface of the San Antonio segment of the Edwards Aquifer, South-Central Texas, 1999-2007

    USGS Publications Warehouse

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

    2009-01-01

    As a part of a 9-year (1999-2007) study done by the U.S. Geological Survey in cooperation with the San Antonio Water System to improve understanding of the San Antonio segment of the Edwards aquifer, south-central Texas, in and near the freshwater/saline-water transition zone of the aquifer, the U.S. Geological Survey collected water-level, borehole geophysical, and water-quality data during 1999-2007 from 37 wells arranged in nine transects (except for two wells) across the freshwater/saline-water interface of the aquifer. This report presents the data collected and also describes the data-collection, analytical, and quality-assurance methods used. The wells, constructed with casing from land surface into the upper part of the aquifer and completed as open hole in the aquifer, are in Uvalde County (East Uvalde transect), in Medina County (South Medina and Devine wells), in Bexar County (Pitluk, Mission, and San Antonio transects), in Comal and Guadalupe Counties (Tri-County transect), in Comal County (New Braunfels transect), and in Hays County (Fish Hatchery, San Marcos, and Kyle transects). Data collected included continuous water level at 18 wells; fluid electrical conductivity and temperature with depth (fluid profiles) obtained by borehole geophysical logging of 15 wells; discrete (periodic) samples for major ions and trace elements at 36 wells; stable isotopes or stable isotopes and tritium at 27 wells; dissolved gases obtained by pumping (or collecting flow) of 19 wells; and continuous specific conductance and temperature at three of the wells equipped with continuous water-level sensors.

  4. Depositional Model for the Middle Eocene Oberlin Sand in Northwest Oberlin Field and Adjacent Areas, Allen Parish, Louisiana: A Well-log and Seismic Analysis

    NASA Astrophysics Data System (ADS)

    McVey, Timothy Keith

    The depositional environment of the middle to late Eocene Oberlin sand of Northwest Oberlin Field and Pilgrim Church Field in central Allen Parish, Louisiana, was investigated. The depositional environment of the Oberlin sand has been interpreted from observations of spontaneous potential log signatures, conventional core reports, paleontological reports, shape of isochore maps, coherency extraction attribute, amplitude extraction attribute, and multiple seismic and subsurface cross sections. Focus is centered on the juxtaposition of component sand bodies and their proximity to the interdistributary and prodelta environments. Sand bodies include distributary channels, distributary mouth bars, crevasse subdeltas and shelfal bars and are interpreted to be the products of lower deltaic and shelf processes. The results of this study are based on seismic analysis, display techniques and subsurface maps calibrated to well logs, models, and recognition criteria of modern and ancient depositional environments previously described in the regional literature. The integration of all available data provides an objective and systematic approach detailing the origin, lateral extent, geometry and architecture of the Oberlin sand in the lower deltaic plain and shelf environments. The results of this study may be applicable to similar age sands on trend with the study area. Understanding of sand component types of the lower deltaic and shelf environments is vital to exploration success and development optimization of hydrocarbon bearing reservoirs.

  5. Preliminary Fracture Description from Core, Lithological Logs, and Borehole Geophysical Data in Slimhole Wells Drilled for Project Hotspot: the Snake River Geothermal Drilling Project

    NASA Astrophysics Data System (ADS)

    Kessler, J. A.; Evans, J. P.; Shervais, J. W.; Schmitt, D.

    2011-12-01

    The Snake River Geothermal Drilling Project (Project Hotspot) seeks to assess the potential for geothermal energy development in the Snake River Plain (SRP), Idaho. Three deep slimhole wells are drilled at the Kimama, Kimberly, and Mountain Home sites in the central SRP. The Kimama and Kimberly wells are complete and the Mountain Home well is in progress. Total depth at Kimama is 1,912 m while total depth at Kimberly is 1,958 m. Mountain Home is expected to reach around 1,900 m. Full core is recovered and complete suites of wireline borehole geophysical data have been collected at both Kimama and Kimberly sites along with vertical seismic profiles. Part of the geothermal assessment includes evaluating the changes in the nature of fractures with depth through the study of physical core samples and analysis of the wireline geophysical data to better understand how fractures affect permeability in the zones that have the potential for geothermal fluid migration. The fracture inventory is complete for the Kimama borehole and preliminary analyses indicate that fracture zones are related to basaltic flow boundaries. The average fracture density is 17 fractures/3 m. The maximum fracture density is 110 fractures/3 m. Fracture density varies with depth and increases considerably in the bottom 200 m of the well. Initial indications are that the majority of fractures are oriented subhorizontally but a considerable number are oriented subvertically as well. We expect to statistically evaluate the distribution of fracture length and orientation as well as analyze local alteration and secondary mineralization that might indicate fluid pathways that we can use to better understand permeability at depth in the borehole. Near real-time temperature data from the Kimama borehole indicate a temperature gradient of 82°C/km below the base of the Snake River Plain aquifer at a depth of 960 m bgs. The measured temperature at around 1,400 m depth is 55°C and the projected temperature at

  6. Method for interpreting well log records to yield indications of gas/oil in an earth formation such as a sandstone, limestone, or dolostone

    SciTech Connect

    Thompson, D.D.; Brown, R.J.S.; Runge, R.J.

    1983-07-12

    The present invention indicates that acoustic characteristics associated with a first well penetrating a gas/oilcontaining strata such as a sandstone, limestone or dolostone, can be normalized (and favorably compared) with similar characteristics of a second, contiguous well of known hydrocarbon potential, such characteristics being calculated and displayed by means of a machineimplemented data processing method in which well logging and geologic data are fed thereto to calculate such characteristics without the need for shear-wave velocities. In more detail, in accordance with the invention brinesaturated bulk and shear moduli, (i.e., Kw and Gw) of a sandstone, limestone or dolostone penetrated by the second well can be predicted as a function of, say, brinesaturated P-wave modulus (Pw) alone (independent of shear-wave velocity). In that way, resulting acoustic values including distinct velocity and amplitude values as a function of a saturation operator can ultimately be provided. Such values, when compared to actual, inwell, field-generated characteristics of the first well, are surprisingly accurate predictors of the amount of gas/oil saturation in and around the first well. The method has particular accuracy in designating gas zones within formations of interest due to use of the complete Benedict-Webb-Rubin non-ideal gas law in psuedo-reduced form.

  7. IMPROVED WELL PLUGGING EQUIPMENT AND WASTE MANGEMENT TECHNIQUES EXCEED ALARA GOALS AT THE OAK RIDGE NATIONAL LABORATORY

    SciTech Connect

    Whiteside, R.; Pawlowicz, R.; Whitehead, L.; Arnseth, R.

    2002-02-25

    In 2000, Bechtel Jacobs Company LLC (BJC) contracted Tetra Tech NUS, Inc. (TtNUS) and their sub-contractor, Texas World Operations, Inc. (TWO), to plug and abandon (P&A) 111 wells located in the Melton Valley area of Oak Ridge National Laboratory (ORNL). One hundred and seven of those wells were used to monitor fluid movement and subsurface containment of the low level radioactive liquid waste/grout slurry that was injected into the Pumpkin Valley Shale Formation, underlying ORNL. Four wells were used as hydrofracture injection wells to emplace the waste in the shale formation. Although the practice of hydrofracturing was and is considered by many to pose no threat to human health or the environment, the practice was halted in 1982 after the Federal Underground Injection Control regulations were enacted by United States Environmental Protection Agency (USEPA) making it necessary to properly close the wells. The work is being performed for the United States Department of Energy Oak Ridge Operations (DOE ORO). The project team is using the philosophy of minimum waste generation and the principles of ALARA (As Low As Reasonably Achievable) as key project goals to minimize personnel and equipment exposure, waste generation, and project costs. Achievement of these goals was demonstrated by the introduction of several new pieces of custom designed well plugging and abandonment equipment that were tested and used effectively during field operations. Highlights of the work performed and the equipment used are presented.

  8. Results of borehole geophysical logging and aquifer-isolation tests conducted in the John Wagner and Sons, Inc former production well, Ivyland, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.

    1997-01-01

    A suite of borehole geophysical logs and heat-pulse-flowmeter measurements run in the former production well at the John Wagner and Sons, Inc. plant indicate two zones of borehole flow. In the upper part of the well, water enters the borehole through a fracture at 90 ft (feet) below floor level, moves upward, and exits the borehole through a fracture at 72 ft below floor level. Water also enters the borehole through fractures at 205-213, 235, and 357 ft below floor level; moves downward; and exits the borehole through fractures at 450-459, 468-470, and 483-490 ft below floor level. Five zones were selected for aquifer-isolation (packer) tests on the basis of borehole geophysical logs. The zones were isolated using a straddle-packer assembly. The lowermost three zones (below 248, 223 to 248, and 198 to 223 ft below floor level) were hydraulically isolated from zones above and below. Specific capacities were 0.12, 0.034, and 0.15 gallons per minute per foot, respectively. The hydrograph from zone 2 (223 to 248 ft below floor level) showed interference from a nearby pumping well. For the upper two zones (81 to 106 and 57 to 81 ft below floor level), similar drawdowns in the isolated zone and the zones above and below the isolated zone indicate that these fractures are hydraulically connected outside the borehole in the unconfined part of the Stockton Formation. The specific capacity of zones 4 and 5 are similar--0.82 and 0.61, respectively.

  9. Attenuation measurements from sonic waveform logs in methane hydrate-bearing sediments at the Nankai Trough exploratory well off Tokai, central Japan

    NASA Astrophysics Data System (ADS)

    Matsushima, Jun

    2005-02-01

    I have used full waveform logs from the Nankai Trough exploratory well off central Japan to estimate both compressional and shear attenuation in sediments containing methane hydrate (MH). The attenuation estimates are based on a median frequency shift to the amplitude spectrum of the recorded waveforms. This paper is concerned with attenuation at sonic frequencies of 10-20 kHz for compressional waves and 500-1000 Hz for shear waves. I observed that the presence of MH increases the host sediments' seismic attenuation, and shear attenuation may be more helpful than compressional attenuation in detecting or characterizing MH-bearing sediments as compressional attenuation is affected by the presence of gas. Moreover, the ratio of compressional to shear attenuation is found to be a more sensitive indicator of the presence of low-saturation gas than the corresponding velocity ratio.

  10. Transaction Logging.

    ERIC Educational Resources Information Center

    Jones, S.; And Others

    1997-01-01

    Discusses the use of transaction logging in Okapi-related projects to allow search algorithms and user interfaces to be investigated, evaluated, and compared. A series of examples is presented, illustrating logging software for character-based and graphical user interface systems, and demonstrating the usefulness of relational database management…

  11. 30 CFR 250.514 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., volumetric, or electronic device for measuring the amount of well-control fluid required to fill the hole... utilized: (1) A fill-up line above the uppermost BOP; (2) A well-control, fluid-volume measuring device for... device. (c) When coming out of the hole with drill pipe, the annulus shall be filled with...

  12. 30 CFR 250.514 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., or electronic device for measuring the amount of well-control fluid required to fill the hole shall... uppermost BOP; (2) A well-control, fluid-volume measuring device for determining fluid volumes when filling... losses. This indicator shall include both a visual and an audible warning device. (c) When coming out...

  13. Remedial Action Plan and Site Design for Stabilization of the Inactive Uranium Mill Tailings Sites at Slick Rock, Colorado: Appendix B to Attachment 3, Lithologic logs and monitor well construction information. Final report

    SciTech Connect

    1995-09-01

    This volume contains lithology logs and monitor well construction information for: NC processing site; UC processing site; and Burro Canyon disposal site. This information pertains to the ground water hydrology investigations which is attachment 3 of this series of reports.

  14. Sandstone and shale compaction curves derived from sonic and gamma ray logs in offshore wells, North Slope, Alaska; parameters for basin modeling

    USGS Publications Warehouse

    Rowan, Elisabeth L.; Hayba, Daniel O.; Nelson, Philip H.; Burns, W. Matthew; Houseknecht, David W.

    2003-01-01

    Representative compaction curves for the principle lithologies are essential input for reliable models of basin history. Compaction curves influence estimates of maximum burial and erosion. Different compaction curves may produce significantly different thermal histories. Default compaction curves provided by basin modeling packages may or may not be a good proxy for the compaction properties in a given area. Compaction curves in the published literature span a wide range, even within one lithology, e.g., sandstone (see Panel 3). An abundance of geophysical well data for the North Slope, from both government and private sources, provides us with an unusually good opportunity to develop compaction curves for the Cretaceous-Tertiary Brookian sandstones, siltstones, and shales. We examined the sonic and gamma ray logs from 19 offshore wells (see map), where significant erosion is least likely to have occurred. Our data are primarily from the Cretaceous-Tertiary Brookian sequence and are less complete for older sequences. For each well, the fraction of shale (Vsh) at a given depth was estimated from the gamma ray log, and porosity was computed from sonic travel time. By compositing porosities for the near-pure sand (Vsh99%)from many individual wells we obtained data over sufficient depth intervals to define sandstone and shale 'master' compaction curves. A siltstone curve was defined using the sonic-derived porosities for Vsh values of 50%. These compaction curves generally match most of the sonic porosities with an error of 5% or less. Onshore, the curves are used to estimate the depth of maximum burial at the end of Brookian sedimentation. The depth of sonic-derived porosity profiles is adjusted to give the best match with the 'master' compaction curves. The amount of the depth adjustment is the erosion estimate. Using our compaction curves, erosion estimates on the North Slope range from zero in much of the offshore, to as much as 1500 ft along the coast, and to

  15. Recovery of Missing Persons in Cyprus: Heavy Equipment Methods and Techniques for Complex Well Excavations.

    PubMed

    Ceker, Deren; Stevens, William D

    2015-11-01

    This technical note presents the methods and techniques developed by the Bi-communal Forensic Team (BCFT) of the Committee on Missing Persons in Cyprus (CMP) used to excavate and exhume the remains of missing persons, many of whom were buried in deep wells at sites across the island of Cyprus during the conflict period of the 1960s and 1970s. A total of 493 Turkish Cypriots and 1508 Greek Cypriots were officially reported missing by the two communities as a result of the conflict. Since the team's formation, in 2005, the BCFT has excavated 114 wells, resulting in the recovery of 195 missing individuals from 35 of these well excavations. The standard excavation approach used by the BCFT, especially for deep well recovery, consists of "ramp," "pocket," and "pool" components. These excavation features enable CMP archaeologists to excavate deep wells safely and efficiently while simultaneously permitting time for thorough documentation and unimpeded recovery of human remains. The team uses three variants of this approach to cope with the variety of geological, physical, and hydrological contexts faced in Cyprus' wells, including hard and soft landforms, the presence or absence of water, and limitations imposed by surrounding infrastructure. The "terracing", "double-ramp", and "single-ramp" variations are detailed with respect to the environmental contexts which prescribe their use. The BCFT's general procedures for human remains recovery and standard well safety protocols conclude the article.

  16. Recovery of Missing Persons in Cyprus: Heavy Equipment Methods and Techniques for Complex Well Excavations.

    PubMed

    Ceker, Deren; Stevens, William D

    2015-11-01

    This technical note presents the methods and techniques developed by the Bi-communal Forensic Team (BCFT) of the Committee on Missing Persons in Cyprus (CMP) used to excavate and exhume the remains of missing persons, many of whom were buried in deep wells at sites across the island of Cyprus during the conflict period of the 1960s and 1970s. A total of 493 Turkish Cypriots and 1508 Greek Cypriots were officially reported missing by the two communities as a result of the conflict. Since the team's formation, in 2005, the BCFT has excavated 114 wells, resulting in the recovery of 195 missing individuals from 35 of these well excavations. The standard excavation approach used by the BCFT, especially for deep well recovery, consists of "ramp," "pocket," and "pool" components. These excavation features enable CMP archaeologists to excavate deep wells safely and efficiently while simultaneously permitting time for thorough documentation and unimpeded recovery of human remains. The team uses three variants of this approach to cope with the variety of geological, physical, and hydrological contexts faced in Cyprus' wells, including hard and soft landforms, the presence or absence of water, and limitations imposed by surrounding infrastructure. The "terracing", "double-ramp", and "single-ramp" variations are detailed with respect to the environmental contexts which prescribe their use. The BCFT's general procedures for human remains recovery and standard well safety protocols conclude the article. PMID:26250595

  17. 3. Log bunkhouse (far left), log chicken house (left of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. Log bunkhouse (far left), log chicken house (left of center), equipment shed (center), and workshop (far right). View to northwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  18. Well construction information, lithologic logs, water level data, and overview of research in Handcart Gulch, Colorado: an alpine watershed affected by metalliferous hydrothermal alteration

    USGS Publications Warehouse

    Caine, Jonathan Saul; Manning, Andrew H.; Verplanck, Philip L.; Bove, Dana J.; Kahn, Katherine Gurley; Ge, Shemin

    2006-01-01

    Integrated, multidisciplinary studies of the Handcart Gulch alpine watershed provide a unique opportunity to study and characterize the geology and hydrology of an alpine watershed along the Continental Divide. The study area arose out of the donation of four abandoned, deep mineral exploration boreholes to the U.S. Geological Survey for research purposes by Mineral Systems Inc. These holes were supplemented with nine additional shallow holes drilled by the U.S. Geological Survey along the Handcart Gulch trunk stream. All of the holes were converted into observation wells, and a variety of data and samples were measured and collected from each. This open-file report contains: (1) An overview of the research conducted to date in Handcart Gulch; (2) well location, construction, lithologic log, and water level data from the research boreholes; and (3) a brief synopsis of preliminary results. The primary purpose of this report is to provide a research overview as well as raw data from the boreholes. Interpretation of the data will be reported in future publications. The drill hole data were tabulated into a spreadsheet included with this digital open-file report.

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

    SciTech Connect

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

    USGS Publications Warehouse

    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

  1. 30 CFR 250.614 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... well is shut in and secured. (b) When coming out of the hole with drill pipe or a workover string, the... hydrostatic pressure 75 pounds per square inch (psi) or every five stands of drill pipe or workover string... string and drill collars that may be pulled prior to filling the hole and the equivalent...

  2. 30 CFR 250.1623 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... hole with drill pipe or a workover string, the annulus shall be filled with well-control fluid before... or workover string, whichever gives a lower decrease in hydrostatic pressure. The number of stands of drill pipe or workover string and drill collars that may be pulled prior to filling the hole and...

  3. 30 CFR 250.614 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... well is shut in and secured. (b) When coming out of the hole with drill pipe or a workover string, the... hydrostatic pressure 75 pounds per square inch (psi) or every five stands of drill pipe or workover string... string and drill collars that may be pulled prior to filling the hole and the equivalent...

  4. 30 CFR 250.614 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... workover string, the annulus shall be filled with well-control fluid before the change in such fluid level... workover string, whichever gives a lower decrease in hydrostatic pressure. The number of stands of drill pipe or workover string and drill collars that may be pulled prior to filling the hole and...

  5. 30 CFR 250.614 - Well-control fluids, equipment, and operations.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... well is shut in and secured. (b) When coming out of the hole with drill pipe or a workover string, the... hydrostatic pressure 75 pounds per square inch (psi) or every five stands of drill pipe or workover string... string and drill collars that may be pulled prior to filling the hole and the equivalent...

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

    USGS Publications Warehouse

    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

  7. Preliminary design of a special casing joint for a well equipped twin horizontal drainholes in the Oxnard field

    SciTech Connect

    Not Available

    1993-12-31

    The Oxnard field is presently under production,with a typical average monthly oil production of about 70,000 B, of which the Vaca Tar sand represents more than half.It is Unitized and operated under cyclic steam injection.The hot Tar and produced water are lifted to the surface with rod pumps equipped for injection of a diluent. The produced WOR is about 2.5 and the GOR is about 150 scf/B. The Vaca Tar sand originally contained about 400 million STB. The estimated recoverable reserve under full-scale cyclic steam injection is 100 to 120 Million STB. Under steamflood, it might reach 240 million STB. The objectives of this field test are: (1) increase well productivity by using a vertical well equipped with twin horizontal drainholes, each of about 1,000 ft. reach; (2) maximize the well draw-down by locating the horizontal wells near the base of the sand layer; (3) reduce capital cost by using twin drainholes connected to the same vertical cased well; (4) reduce operating expenses by eliminating the need for a service rig to pull-out the rods and pump before each steam injection cycle; and (5) be adaptable to other operating modes.

  8. Modeling and analysis of stick-slip and bit bounce in oil well drillstrings equipped with drag bits

    NASA Astrophysics Data System (ADS)

    Kamel, Jasem M.; Yigit, Ahmet S.

    2014-12-01

    Rotary drilling systems equipped with drag bits or fixed cutter bits (also called PDC), used for drilling deep boreholes for the production and the exploration of oil and natural gas, often suffer from severe vibrations. These vibrations are detrimental to the bit and the drillstring causing different failures of equipment (e.g., twist-off, abrasive wear of tubulars, bit damage), and inefficiencies in the drilling operation (reduction of the rate of penetration (ROP)). Despite extensive research conducted in the last several decades, there is still a need to develop a consistent model that adequately captures all phenomena related to drillstring vibrations such as nonlinear cutting and friction forces at the bit/rock formation interface, drive system characteristics and coupling between various motions. In this work, a physically consistent nonlinear model for the axial and torsional motions of a rotating drillstring equipped with a drag bit is proposed. A more realistic cutting and contact model is used to represent bit/rock formation interaction at the bit. The dynamics of both drive systems for rotary and translational motions of the drillstring, including the hoisting system are also considered. In this model, the rotational and translational motions of the bit are obtained as a result of the overall dynamic behavior rather than prescribed functions or constants. The dynamic behavior predicted by the proposed model qualitatively agree well with field observations and published theoretical results. The effects of various operational parameters on the dynamic behavior are investigated with the objective of achieving a smooth and efficient drilling. The results show that with proper choice of operational parameters, it may be possible to minimize the effects of stick-slip and bit-bounce and increase the ROP. Therefore, it is expected that the results will help reduce the time spent in drilling process and costs incurred due to severe vibrations and consequent

  9. 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

    SciTech Connect

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

    1981-11-01

    This report describes part of the work done to fulfill a contract awarded to Gruy Federal, Inc., by the Department of Energy (DOE) on Feburary 12, 1979. The work includes pressure-coring and associated logging and testing programs to provide data on in-situ oil saturation, porosity and permeability distribution, and other data needed for resource characterization of fields and reservoirs in which CO/sub 2/ injection might have a high probability of success. This report details the second such project. 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 incorporating the a, m, and n values obtained from Core Laboratories analysis 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 and production data confirmed the validity of oil saturation determinations. Residual oil saturation, for the perforated and tested intervals were 259 STB/acre-ft for the interval from 4035 to 4055 feet, and 150 STB/acre-ft for the interval from 3692 to 3718 feet. Nine BOPD was produced from the interval 4035 to 4055 feet and no oil was produced from interval 3692 to 3718 feet, qualitatively confirming the relative oil saturations as calculated. 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. This project demonstrates the usefulness of integrating pressure core, log, and production data to realistically evaluate a reservoir for carbon dioxide flood.

  10. Compressional wave character in gassy, near-surface sediments in southern Louisiana determined from variable frequency cross-well, borehole logging, and surface seismic measurements

    SciTech Connect

    Thompson, M.D.; McGinnis, L.D.; Wilkey, P.L.; Fasnacht, T.

    1995-06-01

    Velocity and attenuation data were used to test theoretical equations describing the frequency dependence of compressional wave velocity and attenuation through gas-rich sediments in coastal Louisiana. The cross-well data were augmented with velocities derived from a nearby seismic refraction station using a low-frequency source. Energy at 1 and 3 kHz was successfully transmitted over distances from 3.69 to 30 m; the 5 and 7-kHz data were obtained only at distances up to 20 m. Velocity tomograms were constructed for one borehole pair and covered a depth interval of 10--50 m. Results from the tomographic modeling indicate that gas-induced low velocities are present to depths of greater than 40 m. Analysis of the velocity dispersion suggests that gas-bubble resonance must be greater than 7 kHz, which is above the range of frequencies used in the experiment. Washout of the boreholes at depths above 15 m resulted in a degassed zone containing velocities higher than those indicated in both nearby refraction and reflection surveys. Velocity and attenuation information were obtained for a low-velocity zone centered at a depth of approximately 18 m. Measured attenuations of 1.57, 2.95, and 3.24 dB/m for the 3-, 5-, and 7-kHz signals, respectively, were modeled along with the velocity data using a silt-clay sediment type. Density and porosity data for the model were obtained from the geophysical logs; the bulk and shear moduli were estimated from published relationships. Modeling results indicate that gas bubbles measuring 1 mm in diameter occupy at least 25% to 35% of the pore space.

  11. How Well Does Brazil's Environmental Law Work in Practice? Environmental Impact Assessment and the Case of the Itapiranga Private Sustainable Logging Plan.

    PubMed

    Eve; Arguelles; Fearnside

    2000-09-01

    / The Itapiranga Sustainable Logging Plan provides an example of how Brazil's licensing system functions for logging companies in the state of Amazonas. Two questions need to be dealt with: "How sustainable can logging in the Amazon be?" and "What and how effective are existing legal mechanisms to deal with logging projects?" The environmental impact assessment (EIA) and environmental impact statement (EIS, known as the RIMA in Brazil), present relatively detailed accounts of biodiversity and the need to adopt conservation strategies to protect it. However, social and health impacts are only superficially addressed. The economic sustainability of the operation over multiple cycles is not demonstrated. The multidisciplinary teams responsible for the EIA and EIS (RIMA) reports are hired by the project proponent, an arrangement inherently carrying the risk of biasing the result. Logging reduces biodiversity, releases greenhouse gases and inflicts social and health costs. These impacts reduce the ability of Amazonian forests to provide environmental services and to supply food and livelihood security to local populations. The reports inflate positive effects such as employment: the estimated number of jobs was cut by more than half in a revision made after the EIA and EIS (RIMA) had been approved. Not only do the reports need to be more realistic in assessing both positive and negative consequences of proposed projects, but better means are needed to ensure that promised mitigatory measures are enforced in practice. Many of the lessons that can be drawn from the Itapiranga Plan are not unique to logging projects and apply to licensing of development activites generally in Brazil and elsewhere.

  12. How Well Does Brazil's Environmental Law Work in Practice? Environmental Impact Assessment and the Case of the Itapiranga Private Sustainable Logging Plan.

    PubMed

    Eve; Arguelles; Fearnside

    2000-09-01

    / The Itapiranga Sustainable Logging Plan provides an example of how Brazil's licensing system functions for logging companies in the state of Amazonas. Two questions need to be dealt with: "How sustainable can logging in the Amazon be?" and "What and how effective are existing legal mechanisms to deal with logging projects?" The environmental impact assessment (EIA) and environmental impact statement (EIS, known as the RIMA in Brazil), present relatively detailed accounts of biodiversity and the need to adopt conservation strategies to protect it. However, social and health impacts are only superficially addressed. The economic sustainability of the operation over multiple cycles is not demonstrated. The multidisciplinary teams responsible for the EIA and EIS (RIMA) reports are hired by the project proponent, an arrangement inherently carrying the risk of biasing the result. Logging reduces biodiversity, releases greenhouse gases and inflicts social and health costs. These impacts reduce the ability of Amazonian forests to provide environmental services and to supply food and livelihood security to local populations. The reports inflate positive effects such as employment: the estimated number of jobs was cut by more than half in a revision made after the EIA and EIS (RIMA) had been approved. Not only do the reports need to be more realistic in assessing both positive and negative consequences of proposed projects, but better means are needed to ensure that promised mitigatory measures are enforced in practice. Many of the lessons that can be drawn from the Itapiranga Plan are not unique to logging projects and apply to licensing of development activites generally in Brazil and elsewhere. PMID:10977880

  13. 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

    NASA Astrophysics Data System (ADS)

    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.

  14. 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

    NASA Astrophysics Data System (ADS)

    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

  15. 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

    USGS Publications Warehouse

    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

  16. Microcomputer log analysis system

    SciTech Connect

    Ostrander, C.

    1984-04-01

    A comprehensive friendly log analysis system for use on a microcomputer requires only average log analysis skills. Most systems require both log analysis and computer professional for operation. This one has many capabilities: (1) data entry is handled by office personnel after minimal training; (2) entered data is filed and cataloged for future retrieval and analysis; (3) the system can handle more than 9,000,000 ft (2700 km) of log data in over 60,000 files; (4) all data can be edited; (5) searches and listings can be made using factors such as formation names; (6) facsimile reproductions can be made of any log on file; (7) a screening program turns the system into a sophisticated hand calculator to quickly determine zones of interest; and (8) up to 1100 ft (335 m) of contiguous data from a well can be analyzed in one run. Innovative features include: (1) a discriminating factor to separate reservoirs for individual attention concerning rock type, fluid content and potential reserves; and (2) a written report of each reservoir using artificial intelligence. The report discusses, among other things, the rock type and its consistency, comparing the system finding with the geologist's opinion. Differences between the two will elicit alternative analyses.

  17. Reviews Book: Enjoyable Physics Equipment: SEP Colorimeter Box Book: Pursuing Power and Light Equipment: SEP Bottle Rocket Launcher Equipment: Sciencescope GLE Datalogger Equipment: EDU Logger Book: Physics of Sailing Book: The Lightness of Being Software: Logotron Insight iLog Studio iPhone Apps Lecture: 2010 IOP Schools and Colleges Lecture Web Watch

    NASA Astrophysics Data System (ADS)

    2010-09-01

    WE RECOMMEND Enjoyable Physics Mechanics book makes learning more fun SEP Colorimeter Box A useful and inexpensive colorimeter for the classroom Pursuing Power and Light Account of the development of science in the 19th centuary SEP Bottle Rocket Launcher An excellent resource for teaching about projectiles GLE Datalogger GPS software is combined with a datalogger EDU Logger Remote datalogger has greater sensing abilities Logotron Insight iLog Studio Software enables datlogging, data analysis and modelling iPhone Apps Mobile phone games aid study of gravity WORTH A LOOK Physics of Sailing Book journeys through the importance of physics in sailing The Lightness of Being Study of what the world is made from LECTURE The 2010 IOP Schools and Colleges Lecture presents the physics of fusion WEB WATCH Planet Scicast pushes boundaries of pupil creativity

  18. 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

    SciTech Connect

    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.

  19. Porosity Log Prediction Using Artificial Neural Network

    NASA Astrophysics Data System (ADS)

    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.

  20. New materials for fireplace logs

    NASA Technical Reports Server (NTRS)

    Kieselback, D. J.; Smock, A. W.

    1971-01-01

    Fibrous insulation and refractory concrete are used for logs as well as fireproof walls, incinerator bricks, planters, and roof shingles. Insulation is lighter and more shock resistant than fireclay. Lightweight slag bonded with refractory concrete serves as aggregrate.

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

    SciTech Connect

    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.

  2. Interpretation of 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, 2000-02

    USGS Publications Warehouse

    Senior, Lisa A.; Cinotto, Peter J.; Conger, Randall W.; Bird, Philip H.; Pracht, Karl A.

    2005-01-01

    Ground water in the vicinity of various industrial facilities in Upper Gwynedd Township and Lansdale Borough, Montgomery County, Pa., is contaminated with various 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 beginning autumn 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 a fractured-sedimentary-rock aquifer that acts as a set of confined to partially 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, and this stream flows southwest to bisect 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 16 wells that ranged in depth from 50 to 623 feet. Aquifer-interval-isolation testing was done in 9 of the 16 wells, for a total of 30 zones tested. A multiple-well aquifer test was conducted by monitoring the response of 14 wells to pumping a 600-ft deep production well in February and March 2002. In addition, water levels were monitored continuously in three wells in the area and streamflow was measured quarterly at two sites on Wissahickon Creek from December 2000 through September 2002. Geophysical logging identified water-bearing zones associated with

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

    USGS Publications Warehouse

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

    2015-01-01

    BP-3-USGS was sited to test hypotheses developed from geophysical studies and to answer questions about the history and evolution of Pliocene and Pleistocene Lake Alamosa, which is represented by lacustrine deposits sampled by the well. The findings reported here represent a basis from which future studies can answer these questions and address other important scientific questions in the San Luis Valley regarding geologic history and climate change, groundwater hydrology, and geophysical interpretation.

  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

    USGS Publications Warehouse

    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. 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

    USGS Publications Warehouse

    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.

  6. Log Truck-Weighing System

    NASA Technical Reports Server (NTRS)

    1977-01-01

    ELDEC Corp., Lynwood, Wash., built a weight-recording system for logging trucks based on electronic technology the company acquired as a subcontractor on space programs such as Apollo and the Saturn launch vehicle. ELDEC employed its space-derived expertise to develop a computerized weight-and-balance system for Lockheed's TriStar jetliner. ELDEC then adapted the airliner system to a similar product for logging trucks. Electronic equipment computes tractor weight, trailer weight and overall gross weight, and this information is presented to the driver by an instrument in the cab. The system costs $2,000 but it pays for itself in a single year. It allows operators to use a truck's hauling capacity more efficiently since the load can be maximized without exceeding legal weight limits for highway travel. Approximately 2,000 logging trucks now use the system.

  7. Examining the Role of Topological Factors in Controlling the Hydraulic Conductivity of Granular Deposits Through the Analysis of Geophysical Well Logs: Results From the USGS Toxic Substances Hydrology Site

    NASA Astrophysics Data System (ADS)

    Morin, R. H.; Leblanc, D. R.

    2008-12-01

    Long-term spatial and temporal monitoring of a treated-wastewater plume moving through a sand-and-gravel aquifer has been ongoing at the USGS Toxic Substances Hydrology research site on Cape Cod, Massachusetts, for three decades. The site offers access to numerous wells that penetrate the glacial outwash-plain deposits, and a variety of field experiments has been designed and implemented to investigate aquifer heterogeneity and transport processes. As part of this effort, geophysical logging programs have delineated the spatial variability of hydraulic conductivity, K, by means of a comprehensive series of flowmeter/pumping tests, and correlations among K and other log-derived properties such as porosity, electrical conductivity, and natural gamma activity have been examined statistically to extract information regarding the nature of fluid flow through these materials. Results revealed only a weak or inconclusive dependence of K on porosity from which was inferred that hydraulic conductivity may be influenced more by the topology, or geometric configuration, of the granular mixtures than by the volume of the fluid phase. To investigate the role of pore geometry further, a field experiment was recently conducted in which a sequence of electromagnetic induction logs was recorded in a well to monitor changes in the electrical properties of the surrounding sediments during injection of a saline tracer. The changes resulted from marked contrasts in the specific conductance between the ambient and injected fluids. Analytical mixing models, as well as empirical relations such as Archie's law, have been developed to characterize the electrical properties of saturated rocks and sediments. By applying these relations to the electrical conductivity data combined with the porosity log, topological measures of phase connectivity and surface area along grain boundaries can be derived from downhole measurements. Petrophysical parameters such as formation factor, F, and

  8. Preliminary geological interpretation and lithologic log of the exploratory geothermal test well (INEL-1), Idaho National Engineering Laboratory, eastern Snake River Plain, Idaho

    USGS Publications Warehouse

    Doherty, David J.; McBroome, Lisa Ann; Kuntz, Mel A.

    1979-01-01

    A 10,365 ft (3,159 m) geothermal test well was drilled in the spring of 1979 at the Idaho National Engineering Laboratory, eastern Snake River Plain, Idaho: The majority of rock types encountered in the borehole are of volcanic origin. An upper section above 2,445 ft (745 m) consists of basaltic lava flows and interbedded .sediments of alluvial, lacustrine, and volcanic origin. A lower section below 2,445 ft (745 m) consists exclusively of rhyolitic welded ash-flow tuffs, air-fall ash deposits, nonwelded ash-flow ruffs, and volcaniclastic sediments. The lithology and thickness of the rhyolitic rocks suggest that they are part of an intracaldera fill.

  9. Enhanced carbon-oxygen log interpretations using supplemental log curves

    SciTech Connect

    Wyatt, D.F. Jr.; Jacobson, L.A.; Fox, P.

    1994-12-31

    Supplemental measurements from induced nuclear spectrometry tools are examined to demonstrate what additional information they provide about the well and reservoir conditions. Logs in shut-in wells from Indonesia provide examples of oxygen activation measurements showing cross-flow from one reservoir to another via open perforations. Leaking squeezed perforations were also observed. An example from Alaska shows radioactive scale build-up in the casing which spectral analysis identifies as a mixture of uranium and thorium salts. Another log, where the casing fluid was replaced with crude oil, demonstrates a technique for identifying cement channels. Logs from Nigeria comparing oil saturation estimates before and after a squeeze operation illustrate the effect of casing fluid flushing of the formation through open perforations. Understanding the diagnostic character of these curves leads to higher confidence in the overall log interpretation process.

  10. Interpretation of borehole geophysical logs, aquifer-isolation tests, and water quality, supply wells 1 and 2, Willow Grove Naval Air Station/Joint Reserve Base, Horsham Township, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    Sloto, Ronald A.; Goode, Daniel J.; Frasch, Steven M.

    2002-01-01

    Ground water pumped from supply wells 1 and 2 on the Willow Grove Naval Air Station/Joint Reserve Base (NAS/JRB) provides water for use at the base, including potable water for drinking. The supply wells have been contaminated by volatile organic compounds (VOC?s), particularly trichloroethylene (TCE) and tetrachloroethylene (PCE), and the water is treated to remove the VOC?s. The Willow Grove NAS/JRB and surrounding area are underlain by sedimentary rocks of the Triassic-age Stockton Formation, which form a complex, heterogeneous aquifer. The ground-water-flow system for the supply wells was characterized by use of borehole geophysical logs and heatpulse-flowmeter measurements. The heatpulse-flowmeter measurements showed upward and downward borehole flow under nonpumping conditions in both wells. The hydraulic and chemical properties of discrete water-bearing fractures in the supply wells were characterized by isolating each water-bearing fracture with straddle packers. Eight fractures in supply well 1 and five fractures in supply well 2 were selected for testing on the basis of the borehole geophysical logs and borehole television surveys. Water samples were collected from each isolated fracture and analyzed for VOC?s and inorganic constituents. Fractures at 50?59, 79?80, 196, 124?152, 182, 241, 256, and 350?354 ft btoc (feet below top of casing) were isolated in supply well 1. Specific capacities ranged from 0.26 to 5.7 (gal/min)/ft (gallons per minute per foot) of drawdown. The highest specific capacity was for the fracture isolated at 179.8?188 ft btoc. Specific capacity and depth of fracture were not related in either supply well. The highest concentrations of PCE were in water samples collected from fractures isolated at 236.8?245 and 249.8?258 ft btoc, which are hydraulically connected. The concentration of PCE generally increased with depth to a maximum of 39 mg/L (micrograms per liter) at a depth of 249.8? 258 ft btoc and then decreased to 21 mg/L at a

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

    NASA Astrophysics Data System (ADS)

    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.

  12. Integrated Analysis of Flow, Temperature, and Specific-Conductance Logs and Depth-Dependent Water-Quality Samples from Three Deep Wells in a Fractured-Sandstone Aquifer, Ventura County, California

    USGS Publications Warehouse

    Williams, John H.; Knutson, Kevin D.

    2009-01-01

    Analysis of flow, temperature, and specific-conductance logs and depth-dependent water-quality samples collected under ambient and pumped conditions provided a preliminary delineation of flow zones and water quality in three deep abandoned water-supply wells. The integrated analysis was completed as part of the characterization of a fractured-sandstone aquifer in the mountainous setting of the Santa Susana Field Laboratory in southern Ventura County, California. In the deepest well, which was 1,768 feet deep and had the highest specific capacity (120 gallons per minute per foot), flow zones were detected at 380 feet (base of casing) and at 440, 595, and 770 feet in the open hole. Under ambient conditions, measured flow was downward from the 380- and 440-foot zones to the 595- and 770-foot zones. Under pumped conditions, most of flow was contributed by the 595-foot zone. Flow from the 380- and 440-foot zones appeared to have lower specific conductance and higher trichloroethylene concentrations than that from the 595-foot zone. In the shallowest well, which was reportedly 940 feet deep but only logged to 915 feet due to blockage, flow zones were detected behind the perforated casing and at 867 feet in the open hole. Under ambient conditions, downward and upward flows appeared to exit at a zone behind the perforated casing at 708 feet. Most of the pumped flow was contributed from zones behind the perforated casing between 565 and 708 feet. Pumped flow also was contributed by zones at 867 feet and below the logged depth. Volatile organic compounds were not detected in the ambient and pumped flows. In the third well, which was 1,272 feet deep and had the lowest specific capacity (3.6 gallons per minute per foot), flow zones were detected in the open hole above and just below the water level near 337 feet and at 615, 785, 995, and 1,070 feet. Under ambient conditions, measured flow in well was downward from the shallowmost zones to the 995-foot zone. Fracture zones at

  13. A risk index for multicriterial selection of a logging system with low environmental impact

    SciTech Connect

    Horodnic, Sergiu Andrei

    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.

  14. Impeller flow-meter logging of vertical cross flow between basalt aquifers through wells at the Idaho National Engineering Laboratory, Eastern Snake River Plain, Idaho. Progress report, June 22, 1992

    SciTech Connect

    Bennecke, W.M.; Wood, S.H.

    1992-12-31

    An impeller flowmeter was used with a COLOG digital acquisition system to determine existing borehole flows, to compare with previous logging results, and to acquire flow measurements of vertical cross-flow of water in the wells between permeable zones in the open-hole intervals. The direction of flow found was predominantly downward with velocities ranging from 0-30 ft/min. Some flow reversals were noted and attributed to nearby pumping wells. USGS wells 44 and 46 were studied in September, 1991 near the Idaho Chemical Processing Plant (ICPP). The results showed a usual overall flow direction downward with flow entering the wells at around 510 to 600 ft. below the land surface. Water exited these wells at lower levels around 550 to 580 ft. Flow velocities ranged up to 24 ft/min. Using published aquifer parameters, the rate of propagation of a pressure change in an aquifer was calculated for the well CPP-2 turning on and off, at 3100 gpm.

  15. Estimation of Performance of an Active Well Coincidence Counter Equipped with Boron-Coated Straw Neutron Detectors - 13401

    SciTech Connect

    Young, B.M.; Lacy, J.L.; Athanasiades, A.

    2013-07-01

    He-3, a very rare isotope of natural helium gas, has ideal properties for the detection of thermal neutrons. As such it has become the standard material for neutron detectors and sees ubiquitous use within many radiometric applications that require neutron sensitivity. Until recently, there has been a fairly abundant supply of He-3. However, with the reduction in nuclear weapons, production of tritium ceased decades ago and the stockpile has largely decayed away, reducing the available He-3 supply to a small fraction of that needed for neutron detection. A suitable and rapidly-deployable replacement technology for neutron detectors must be found. Many potential replacement technologies are under active investigation and development. One broad class of technologies utilizes B-10 as a neutron capture medium in coatings on the internal surfaces of proportional detectors. A particular implementation of this sort of technology is the boron-coated 'straw' (BCS) detectors under development by Proportional Technologies, Inc. (PTi). This technology employs a coating of B-10 enriched boron carbide (B{sub 4}C) on the inside of narrow tubes, roughly 4 mm in diameter. A neutron counter (e.g. a slab, a well counter, or a large assay counter designed to accommodate 200 liter drums) could be constructed by distributing these narrow tubes throughout the polyethylene body of the counter. One type of neutron counter that is of particular importance to safeguards applications is the Active Well Coincidence Counter (AWCC), which is a Los Alamos design that traditionally employs 42 He-3 detectors. This is a very flexible design which can accurately assay small samples of uranium- and plutonium-bearing materials. Utilizing the MCNPX code and benchmarking against measurements where possible, the standard AWCC has been redesigned to utilize the BCS technology. Particular aspects of the counter performance include the single-neutron ('singles') detection efficiency and the time constant for

  16. Log-burning stove

    SciTech Connect

    Choate, J.R.

    1982-11-23

    A log-burning stove having a stove door with an angled plate element secured thereto, the top portion of the plate element deflecting combustion gases inwardly to the combustion chamber, and the lower portion deflecting draft air inwardly and downwardly into the combustion chamber, the plate element also forming a log-support and log-sliding surface.

  17. Log N-log S in inconclusive

    NASA Technical Reports Server (NTRS)

    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.

  18. Log N-log S is inconclusive

    SciTech Connect

    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.

  19. LogScope

    NASA Technical Reports Server (NTRS)

    Havelund, Klaus; Smith, Margaret H.; Barringer, Howard; Groce, Alex

    2012-01-01

    LogScope is a software package for analyzing log files. The intended use is for offline post-processing of such logs, after the execution of the system under test. LogScope can, however, in principle, also be used to monitor systems online during their execution. Logs are checked against requirements formulated as monitors expressed in a rule-based specification language. This language has similarities to a state machine language, but is more expressive, for example, in its handling of data parameters. The specification language is user friendly, simple, and yet expressive enough for many practical scenarios. The LogScope software was initially developed to specifically assist in testing JPL s Mars Science Laboratory (MSL) flight software, but it is very generic in nature and can be applied to any application that produces some form of logging information (which almost any software does).

  20. Depth dependent multiple logging system

    SciTech Connect

    Howells, A. P. S.; Angehrn, J. A.; Dienglewicz, A. M.; Viswanathan, R.

    1985-12-03

    An improved well logging technique is provided for more accurately deriving and correlating a plurality of measurements made during a single traversal of a logging instrument through subsurface formations. In one exemplary embodiment, methods and apparatus are provided for deriving a more accurate and precise measurement of depth at which real-time logging measurements are made, and in particular for correcting anomalies occurring in the depth indication from cable stretch, yo-yo of the sonde in the borehole and the like. The more accurate and precise depth measurement is then utilized for generating well logging measurements on a depth-dependent basis, deriving at least some of such measurements in digital form and alternately transmitting to the surface digital and analog representations of such measurements. Furthermore, methods and apparatus are provided for deriving measurements of subsurface earth formation from a plurality of logging instruments combined in a single tool, wherein such measurements are made during a single pass through a borehole with the resultant measurement data correlatively merged, recorded and displayed.

  1. Ulysses log 1992

    NASA Technical Reports Server (NTRS)

    Perez, Raul Garcia

    1993-01-01

    The Ulysses Log tells the story of some intriguing problems that we (=The Spacecraft Team) have encountered. Ulysses was launched on 6 Oct. 1990, and it made the fastest trip to Jupiter (8 Feb. 1992). It is presently going out of the ecliptic. This paper presents log entries from the following areas: (1) ingenious maneuvers; (2) telecommunication problems; and (3) surprises.

  2. Log-Tool

    2012-05-21

    Log files are typically semi- or un-structured. To be useable for visualization and machine learning, they need to be parsed into a standard, structured format. Log-tool is a tool for facilitating the parsing, structuring, and routing of log files (e.g. intrusion detection long, web server logs, system logs). It consists of three main components: (1) Input – it will input data from files, standard input, and syslog, (2) Parser – it will parse the logmore » file based on regular expressions into structured data (JSNO format), (3) Output – it will output structured data into commonly used formats, including Redis (a database), standard output, and syslog.« less

  3. Acoustic paramagnetic logging tool

    DOEpatents

    Vail, III, William B.

    1988-01-01

    New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth3 s magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation . The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores.

  4. 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

    SciTech Connect

    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

  5. 6. Log calving barn. Interior view showing log postandbeam support ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. Log calving barn. Interior view showing log post-and-beam support system and animal stalls. - William & Lucina Bowe Ranch, Log Calving Barn, 230 feet south-southwest of House, Melrose, Silver Bow County, MT

  6. EE-3A Logging Report

    SciTech Connect

    Anderson, David W.

    1993-12-15

    Two logs of EE-3A were performed during the last couple of weeks. The first of which, was a Temperature/Casing-Collar Locator (CCL) log, which took place on Friday, December 10th., 1993. The second log was a Caliper log which was done in cooperation with the Dia-Log Company, of Odessa, TX. on Monday, December, 13th., 1993.

  7. Lithologic logs and geophysical logs from test drilling in Palm Beach County, Florida, since 1974

    USGS Publications Warehouse

    Swayze, Leo J.; McGovern, Michael C.; Fischer, John N.

    1980-01-01

    Test-hole data that may be used to determine the hydrogeology of the zone of high permeability in Palm Beach County, Fla., are presented. Lithologic logs from 46 test wells and geophysical logs from 40 test wells are contained in this report. (USGS)

  8. NMR logging apparatus

    DOEpatents

    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.

  9. Outcrop gamma-ray logging applied to subsurface petroleum geology

    SciTech Connect

    Slatt, R.M.; Borer, J.M.; Horn, B.W.

    1995-10-01

    Developing a gamma-ray log profile of an outcrop with a hand-held scintillometer has many applications to subsurface petroleum geology. The outcrop gamma-ray log provides a readily understandable bridge between what is observed in outcrop and what is to be interpreted on well logs and seismic records. Several examples are presented in this paper that demonstrate major applications. An outcrop from the Cretaceous Mesaverde Group in Colorado provides an excellent example of the use of outcrop gamma-ray logs to better visualize spatial variability of depositional settings for improved well log correlations. Out crops from the Cretaceous Almond Formation, Niobrara Formation, and Graneros Shale in Colorado serve as examples of outcrop gamma-ray logging used to correlate outcrops with their subsurface equivalents for improved lithologic and stratigraphic interpretation of well logs. Outcrops of the Cretaceous Sharon Springs Member of the Pierre Shale in Colorado and the Eocene Green River Formation in Wyoming provide examples of the application of outcrop-gamma ray logging to identify and characterize organic-rich shales in outcrops and on well logs. Outcrops of the Pennsylvanian Jackfork Formation in Arkansas demonstrate the use of outcrop logging to yield improved interpretation of reservoir quality on well logs and for one- and two-dimensional seismic modeling. An outcrop of Precambrian and Cambro-Ordovician rocks from Algeria provides an example of outcrop logging to recognize unconformities and other major surfaces on well logs. An outcrop of the Niobrara Formation in Colorado is used as an example for improved understanding of horizontal gamma-ray log response. The example logs presented are all drived with a hand-held scintillometer. This technique is simple, quick, and relatively inexpensive, so is recommended for any outcrop work that is intended to be applied t;o subsurface well logs or seismic interpretation.

  10. 4. Log chicken house (far left foreground), log bunkhouse (far ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. Log chicken house (far left foreground), log bunkhouse (far left background), one-room log cabin (left of center background), log root cellar (center), post-and-beam center in foreground, and blacksmith shop (far right foreground). View to southeast. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  11. Interactive Reflective Logs

    ERIC Educational Resources Information Center

    Deaton, Cynthia Minchew; Deaton, Benjamin E.; Leland, Katina

    2010-01-01

    The authors created an interactive reflective log (IRL) to provide teachers with an opportunity to use a journal approach to record, evaluate, and communicate student understanding of science concepts. Unlike a traditional journal, the IRL incorporates prompts to encourage students to discuss their understanding of science content and science…

  12. Logs Perl Module

    2007-04-04

    A perl module designed to read and parse the voluminous set of event or accounting log files produced by a Portable Batch System (PBS) server. This module can filter on date-time and/or record type. The data can be returned in a variety of formats.

  13. Logging on to Learn

    ERIC Educational Resources Information Center

    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,…

  14. Log of Apollo 11.

    ERIC Educational Resources Information Center

    National Aeronautics and Space Administration, Washington, DC.

    The major events of the first manned moon landing mission, Apollo 11, are presented in chronological order from launch time until arrival of the astronauts aboard the U.S.S. Hornet. The log is descriptive, non-technical, and includes numerous color photographs of the astronauts on the moon. (PR)

  15. 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

    USGS Publications Warehouse

    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

  16. 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

    NASA Astrophysics Data System (ADS)

    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

  17. Energy saving and endurance log for a log building

    SciTech Connect

    Dolata, G.

    1987-03-17

    A log is described for construction of a log building which comprises: an elongated peeled log of substantially uniform diameter along its length with parallel end faces, a bottom surface of the log having a concave surface configuration centered on a diametrical line of the log, a rounded top surface directly opposite from the concave bottom surface which mates with a concave surface of another log when placed upon the rounded top surface, a vertically extending longitudinal slot in the top surface of the log that extends the length of the log, a vertically extending longitudinal slot along at least one side of the log with the slot extending vertically substantially parallel with the diametrical line with the slot being formed outwardly of the concave surface, the log including at least one butt end, the butt end including an end slot along the diametrical line which extends from a top of the log down through the butt end to the concave surface; and the butt includes at least one short, longitudinally extending arcuate groove near an outer surface of the log which extends from a line juxtaposed the end slot down to at least one longitudinal slot in the log.

  18. 2. Onroom log cabin (right), log root cellar (center), tworoom ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. On-room log cabin (right), log root cellar (center), two-room log cabin (left), and post-and-beam garage (background). View to southwest. - William & Lucina Bowe Ranch, County Road 44, 0.1 mile northeast of Big Hole River Bridge, Melrose, Silver Bow County, MT

  19. My Journey with Learning Logs

    ERIC Educational Resources Information Center

    Hurst, Beth

    2005-01-01

    Learning logs, or reading response logs, have long been established as an effective reading strategy that helps students learn from text (Atwell, 1987; Blough & Berman, 1991; Calkins, 1986; Commander & Smith, 1996; Kuhrt & Farris, 1990; Reed, 1988; Sanders, 1985). In this paper, the author describes her experiences using learning logs as a…

  20. Grid Logging: Best Practices Guide

    SciTech Connect

    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.

  1. 10 CFR 39.51 - Use of a sealed source in a well without a surface casing.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Use of a sealed source in a well without a surface casing. 39.51 Section 39.51 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.51 Use of a sealed source in a well without a surface casing....

  2. 10 CFR 39.51 - Use of a sealed source in a well without a surface casing.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Use of a sealed source in a well without a surface casing. 39.51 Section 39.51 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.51 Use of a sealed source in a well without a surface casing....

  3. Selective Logging, Fire, and Biomass in Amazonia

    NASA Technical Reports Server (NTRS)

    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.

  4. Salvage logging, ecosystem processes, and biodiversity conservation.

    PubMed

    Lindenmayer, D B; Noss, R F

    2006-08-01

    We summarize the documented and potential impacts of salvage logging--a form of logging that removes trees and other biological material from sites after natural disturbance. Such operations may reduce or eliminate biological legacies, modify rare postdisturbance habitats, influence populations, alter community composition, impair natural vegetation recovery, facilitate the colonization of invasive species, alter soil properties and nutrient levels, increase erosion, modify hydrological regimes and aquatic ecosystems, and alter patterns of landscape heterogeneity These impacts can be assigned to three broad and interrelated effects: (1) altered stand structural complexity; (2) altered ecosystem processes and functions; and (3) altered populations of species and community composition. Some impacts may be different from or additional to the effects of traditional logging that is not preceded by a large natural disturbance because the conditions before, during, and after salvage logging may differ from those that characterize traditional timber harvesting. The potential impacts of salvage logging often have been overlooked, partly because the processes of ecosystem recovery after natural disturbance are still poorly understood and partly because potential cumulative effects of natural and human disturbance have not been well documented. Ecologically informed policies regarding salvage logging are needed prior to major natural disturbances so that when they occur ad hoc and crisis-mode decision making can be avoided. These policies should lead to salvage-exemption zones and limits on the amounts of disturbance-derived biological legacies (e.g., burned trees, logs) that are removed where salvage logging takes place. Finally, we believe new terminology is needed. The word salvage implies that something is being saved or recovered, whereas from an ecological perspective this is rarely the case.

  5. Logjam: A scalable unified log file archiver

    SciTech Connect

    Cardo, Nicholas P.

    2001-08-01

    Log files are a necessary record of events on any system. However, as systems scale, so does the volume of data captured. To complicate matters, this data can be distributed across all nodes within the system. This creates challenges in ways to obtain these files as well as archiving them in a consistent manner. It has become commonplace to develop a custom written utility for each system that is tailored specifically to that system. For computer centers that contain multiple systems, each system would have their own respective utility for gathering and archiving log files. Each time a new log file is produced, a modification to the utility is necessary. With each modification, risks of errors could be introduced as well as spending time to introduce that change. This is precisely the purpose of logjam. Once installed, the code only requires modification when new features are required. A configuration file is used to identify each log file as well as where to harvest it and how to archive it. Adding a new log file is as simple as defining it in a configuration file and testing can be performed in the production environment.

  6. Logjam: A scalable unified log file archiver

    2001-08-01

    Log files are a necessary record of events on any system. However, as systems scale, so does the volume of data captured. To complicate matters, this data can be distributed across all nodes within the system. This creates challenges in ways to obtain these files as well as archiving them in a consistent manner. It has become commonplace to develop a custom written utility for each system that is tailored specifically to that system. Formore » computer centers that contain multiple systems, each system would have their own respective utility for gathering and archiving log files. Each time a new log file is produced, a modification to the utility is necessary. With each modification, risks of errors could be introduced as well as spending time to introduce that change. This is precisely the purpose of logjam. Once installed, the code only requires modification when new features are required. A configuration file is used to identify each log file as well as where to harvest it and how to archive it. Adding a new log file is as simple as defining it in a configuration file and testing can be performed in the production environment.« less

  7. North Sea HPHT wells require changes in drilling procedures

    SciTech Connect

    Baller, H.

    1991-03-11

    Such equipment as casing, drillstrings, mud, logging, and rigs that were adequate to drill most of the North Sea wells to date will require modifications to drill the high-pressure, high-temperature (HPHT) formations in the Central Graben of the North Sea. HPHT exploration wells are slowly becoming part of the drilling scenario in the North Sea Central Graben. Predominantly drilled in the U.K., an increasing number are now planned for the Norwegian sector during 1991.

  8. Memory logging tools

    SciTech Connect

    Lysne, P. )

    1993-01-01

    A suite of memory logging tools is being developed for slim-hole, high-temperature applications. The first tool will measure pressure and temperature, and it is especially designed to be a low-cost, but very precise, device. This tool will be smart in the sense that it can make [open quotes]decisions[close quotes] downhole. A second tool will measure the gamma-ray emissions from formation material, and it will be an indicator of lithology. A fluid sampling tool will complement the spectral gamma tool in that is will further constrain the lithology by identifying dissolved formation materials. Plans are being made to integrate the tool responses into formation parameters of interest through cooperative efforts between geothermal operators and scientific drilling programs.

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

    NASA Technical Reports Server (NTRS)

    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.

  10. 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

    NASA Astrophysics Data System (ADS)

    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

  11. Hanford wells

    SciTech Connect

    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.

  12. Oracle Log Buffer Queueing

    SciTech Connect

    Rivenes, A S

    2004-12-08

    The purpose of this document is to investigate Oracle database log buffer queuing and its affect on the ability to load data using a specialized data loading system. Experiments were carried out on a Linux system using an Oracle 9.2 database. Previous experiments on a Sun 4800 running Solaris had shown that 100,000 entities per minute was an achievable rate. The question was then asked, can we do this on Linux, and where are the bottlenecks? A secondary question was also lurking, how can the loading be further scaled to handle even higher throughput requirements? Testing was conducted using a Dell PowerEdge 6650 server with four CPUs and a Dell PowerVault 220s RAID array with 14 36GB drives and 128 MB of cache. Oracle Enterprise Edition 9.2.0.4 was used for the database and Red Hat Linux Advanced Server 2.1 was used for the operating system. This document will detail the maximum observed throughputs using the same test suite that was used for the Sun tests. A detailed description of the testing performed along with an analysis of bottlenecks encountered will be made. Issues related to Oracle and Linux will also be detailed and some recommendations based on the findings.

  13. Development of pulsed neutron uranium logging instrument

    SciTech Connect

    Wang, Xin-guang; Liu, Dan; Zhang, Feng

    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.

  14. Terminology Extraction from Log Files

    NASA Astrophysics Data System (ADS)

    Saneifar, Hassan; Bonniol, Stéphane; Laurent, Anne; Poncelet, Pascal; Roche, Mathieu

    The log files generated by digital systems can be used in management information systems as the source of important information on the condition of systems. However, log files are not exhaustively exploited in order to extract information. The classical methods of information extraction such as terminology extraction methods are irrelevant to this context because of the specific characteristics of log files like their heterogeneous structure, the special vocabulary and the fact that they do not respect a natural language grammar. In this paper, we introduce our approach Exterlog to extract the terminology from log files. We detail how it deals with the particularity of such textual data.

  15. Log evaluation of oil-bearing igneous rocks

    SciTech Connect

    Khatchikian, A.

    1983-12-01

    The evaluation of porosity, water saturation and clay content of oilbearing igneous rocks with well logs is difficult due to the mineralogical complexity of this type of rocks. The log responses to rhyolite and rhyolite tuff; andesite, dacite and zeolite tuff; diabase and basalt have been studied from examples in western Argentina and compared with values observed in other countries. Several field examples show how these log responses can be used in a complex lithology program to make a complete evaluation.

  16. Logging Concessions Enable Illegal Logging Crisis in the Peruvian Amazon

    NASA Astrophysics Data System (ADS)

    Finer, Matt; Jenkins, Clinton N.; Sky, Melissa A. Blue; Pine, Justin

    2014-04-01

    The Peruvian Amazon is an important arena in global efforts to promote sustainable logging in the tropics. Despite recent efforts to achieve sustainability, such as provisions in the US-Peru Trade Promotion Agreement, illegal logging continues to plague the region. We present evidence that Peru's legal logging concession system is enabling the widespread illegal logging via the regulatory documents designed to ensure sustainable logging. Analyzing official government data, we found that 68.3% of all concessions supervised by authorities were suspected of major violations. Of the 609 total concessions, nearly 30% have been cancelled for violations and we expect this percentage to increase as investigations continue. Moreover, the nature of the violations indicate that the permits associated with legal concessions are used to harvest trees in unauthorized areas, thus threatening all forested areas. Many of the violations pertain to the illegal extraction of CITES-listed timber species outside authorized areas. These findings highlight the need for additional reforms.

  17. Borehole Calibration Facilities to Support Gamma Logging for Hanford Subsurface Investigation and Contaminant Monitoring - 13516

    SciTech Connect

    McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W.

    2013-07-01

    Repeated gamma logging in cased holes represents a cost-effective means to monitor gamma-emitting contamination in the deep vadose zone over time. Careful calibration and standardization of gamma log results are required to track changes and to compare results over time from different detectors and logging systems. This paper provides a summary description of Hanford facilities currently available for calibration of logging equipment. Ideally, all logging organizations conducting borehole gamma measurements at the Hanford Site will take advantage of these facilities to produce standardized and comparable results. (authors)

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

    NASA Technical Reports Server (NTRS)

    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.

  19. Hanford wells

    SciTech Connect

    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.

  20. Expandable slotted tubes offer well design benefits

    SciTech Connect

    Metcalfe, P.

    1996-10-01

    Multilateral wells can reduce well count by accessing multiple targets from one main overburden penetration. However, isolated laterals capable of handling increased production require a larger casing scheme than normal, along with whipstocks, plugs, gauges and downhole control valves. All this equipment is difficult to include in a slimhole or monobore multilateral well design. In many instances slimhole technology and multilateral designs are not compatible. Expanded slotted tubing (EST) technology was designed to complement multilateral and slimhole monobore applications as well as conventional wells. The paper describes the concept, alternative borehole liner, downhole forces, a case history from a southwestern Texas field, objectives, formation pressure testing, EST running and cementing, EST expansion, drill-out, log and pressure test, and EST as a completion liner for multilateral wells.

  1. Hydraulic control of subsea well equipment

    SciTech Connect

    Hurta, G. L.; Milberger, L. J.; Williams, A. M.

    1985-02-05

    A control system employable for purposes of effecting the operation of a plurality of actuable devices, which are located at a subsea site, from a position that is remote therefrom. More specifically, the subject control system is particularly suited for employment for purposes of hydraulically effecting the operation of the valves of a subsea christmas tree. To this end, the subject control system, on the one hand, is connected in fluid flow relation with a surface control center from whence hydraulic fluid is supplied under pressure, and, on the other hand, is connected to a subsea sequence valving means which receives the hydraulic fluid under pressure from the surface control center and in turn transmits hydraulic power to the operators of the christmas tree valves to cause the latter to move in accordance with a predetermined operating program. The subject control system is characterized by the flexibility that is possesses in terms of the diversity of operating programs than can be employed therewith, by the fact that the sequence valving means embodies constant force spring means which enables the elimination of one hydraulic line between the surface control center and the subsea site of the christmas tree, and by the embodiment in the subsea sequence valving means of new and improved duplex shear seal means operative for preventing interflow.

  2. 47 CFR 80.409 - Station logs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 5 2010-10-01 2010-10-01 false Station logs. 80.409 Section 80.409... MARITIME SERVICES Station Documents § 80.409 Station logs. (a) General requirements. Logs must be established and properly maintained as follows: (1) The log must be kept in an orderly manner. The log may...

  3. 10 CFR 39.13 - Specific licenses for well logging.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... shall submit a description of its overall organizational structure as it applies to the radiation safety... this chapter for byproduct material, in § 40.32 of this chapter for source material, and in § 70.33 of this chapter for special nuclear material, as appropriate, and any special requirements contained...

  4. APS logDaemon and client library

    SciTech Connect

    Saunders, C.; Kowalkowski, J.

    1995-12-13

    This document serves as a User`s Manual and Reference for the logDaemon and client library. This package provides a general distributed message logging system. A logDaemon may be started anywhere on a subnet. A client which has linked in the client library is provided functions to open a connection to the logDaemon, log messages, and close the connection. The logDaemon maintains one or more log files (in simple ASCII or SDDS format) and an e-mail list based on specifications in a configuration file. Incoming messages are logged to the appropriate file and/or result in e-mail being sent.

  5. Instruments and methods acoustic televiewer logging in glacier boreholes

    USGS Publications Warehouse

    Morin, R.H.; Descamps, G.E.; Cecil, L.D.

    2000-01-01

    The acoustic televiewer is a geophysical logging instrument that is deployed in a water-filled borehole and operated while trolling. It generates a digital, magnetically oriented image of the borehole wall that is developed from the amplitudes and transit times of acoustic waves emitted from the tool and reflected at the water-wall interface. The transit-time data are also converted to radial distances, from which cross-sectional views of the borehole shape can be constructed. Because the televiewer is equipped with both a three-component magnetometer and a two-component inclinometer, the borehole's trajectory in space is continuously recorded as well. This instrument is routinely used in mining and hydrogeologic applications, but in this investigation it was deployed in two boreholes drilled into Upper Fremont Glacier, Wyoming, U.S.A. The acoustic images recorded in this glacial setting are not as clear as those typically obtained in rocks, due to a lower reflection coefficient for water and ice than for water and rock. Results indicate that the depth and orientation of features intersecting the boreholes can be determined, but that interpreting their physical nature is problematic and requires corroborating information from inspection of cores. Nevertheless, these data can provide some insight into englacial structural characteristics. Additional information derived from the cross-sectional geometry of the borehole, as well as from its trajectory, may also be useful in studies concerned with stress patterns and deformation processes.

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

    PubMed

    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. PMID:25092495

  7. Heimdal monitoring. 1: Establishing feasibility from cores and logs

    SciTech Connect

    Jizba, D.L.; Marion, D.P.

    1994-12-31

    This paper presents a method that uses core and log measurements to quantify the influence of saturation changes on elastic properties at core, log, and seismic scales in order to investigate the feasibility of using seismic measurements to monitor gas production on the Heimdal North Sea field. In the first part, laboratory measurements of P- and S-wave velocities, porosity, density, and mineralogy are used to determined the influence of partial saturation on elastic parameters. These measurement are compared with theoretical predictions using Gassmann`s model. Second, the authors invert from logs, the rock parameters that are necessary to simulate the impact of water rise on elastic properties at log scale. Third, the well logs are modelled at seismic scales of resolution and are used to identify the effect of fluid movement on the seismic response. Finally, the results are compared to repetitive seismic measurements.

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

    PubMed

    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.

  9. [Medical Equipment Maintenance Methods].

    PubMed

    Liu, Hongbin

    2015-09-01

    Due to the high technology and the complexity of medical equipment, as well as to the safety and effectiveness, it determines the high requirements of the medical equipment maintenance work. This paper introduces some basic methods of medical instrument maintenance, including fault tree analysis, node method and exclusive method which are the three important methods in the medical equipment maintenance, through using these three methods for the instruments that have circuit drawings, hardware breakdown maintenance can be done easily. And this paper introduces the processing methods of some special fault conditions, in order to reduce little detours in meeting the same problems. Learning is very important for stuff just engaged in this area.

  10. INSPIRE and SPIRES Log File Analysis

    SciTech Connect

    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.

  11. Mail LOG: Program operating instructions

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    The operating instructions for the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS, are provided. The program is written in FORTRAN for the PRIME 300 computer system. The MAIL LOG program has the following four modes of operation: (1) INPUT - putting new records into the data base (2) REVISE - changing or modifying existing records in the data base (3) SEARCH - finding special records existing in the data base (4) ARCHIVE - store or put away existing records in the data base. The output includes special printouts of records in the data base and results from the INPUT and SEARCH modes. The MAIL LOG data base consists of three main subfiles: Incoming and outgoing mail correspondence; Design Information Releases and Releases and Reports; and Drawings and Engineering orders.

  12. Postfire logging in riparian areas.

    PubMed

    Reeves, Gordon H; Bisson, Peter A; Rieman, Bruce E; Benda, Lee E

    2006-08-01

    We reviewed the behavior of wildfire in riparian zones, primarily in the western United States, and the potential ecological consequences of postfire logging. Fire behavior in riparian zones is complex, but many aquatic and riparian organisms exhibit a suite of adaptations that allow relatively rapid recovery after fire. Unless constrained by other factors, fish tend to rebound relatively quickly, usually within a decade after a wildfire. Additionally, fire and subsequent erosion events contribute wood and coarse sediment that can create and maintain productive aquatic habitats over time. The potential effects of postfire logging in riparian areas depend on the landscape context and disturbance history of a site; however available evidence suggests two key management implications: (1) fire in riparian areas creates conditions that may not require intervention to sustain the long-term productivity of the aquatic network and (2) protection of burned riparian areas gives priority to what is left rather than what is removed. Research is needed to determine how postfire logging in riparian areas has affected the spread of invasive species and the vulnerability of upland forests to insect and disease outbreaks and how postfire logging will affect the frequency and behavior of future fires. The effectiveness of using postfire logging to restore desired riparian structure and function is therefore unproven, but such projects are gaining interest with the departure of forest conditions from those that existed prior to timber harvest, fire suppression, and climate change. In the absence of reliable information about the potential consequence of postfire timber harvest, we conclude that providing postfire riparian zones with the same environmental protections they received before they burned isjustified ecologically Without a commitment to monitor management experiments, the effects of postfire riparian logging will remain unknown and highly contentious.

  13. Method for induced polarization logging

    SciTech Connect

    Vinegar, H.J.; Waxman, M.H.

    1987-04-14

    A method is described for generating a log of the formation phase shift, resistivity and spontaneous potential of an earth formation from data obtained from the earth formation with a multi-electrode induced polarization logging tool. The method comprises obtaining data samples from the formation at measurement points equally spaced in time of the magnitude and phase of the induced voltage and the magnitude and phase of the current supplied by a circuit through a reference resistance R/sub 0/ to a survey current electrode associated with the tool.

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

    PubMed

    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.

  15. A proven record in changing attitudes about MWD logs

    SciTech Connect

    Cantrell, L.; Paxson, K.B.; Keyser, W.L.; Ball, S.

    1993-07-01

    Measurement while drilling (MWD) logs for quantitative reservoir characterization were evaluated during drilling of Gulf of Mexico flexure trend projects, Kilauea (Green Canyon Blocks 6 and 50) and Tick (Garden Banks Block 189). Comparisons confirmed that MWD can be used as an accurate replacement for wireline logging when borehole size is not a limiting factor. Texaco MWD experience evolved from last resort' to primary formation evaluation logging, which resulted in rigtime and associated cost savings. Difficult wells are now drilled and evaluated with confidence, geopressure is safely monitored, conventional core interval tops are selected, and geologic interpretations and operational decisions are made before wells TD. This paper reviews the performance, accuracy, and limitations of the MWD systems and compares the results to standard geophysical well logging techniques. Four case histories are presented.

  16. Solar Equipment

    NASA Technical Reports Server (NTRS)

    1983-01-01

    A medical refrigeration and a water pump both powered by solar cells that convert sunlight directly into electricity are among the line of solar powered equipment manufactured by IUS (Independent Utility Systems) for use in areas where conventional power is not available. IUS benefited from NASA technology incorporated in the solar panel design and from assistance provided by Kerr Industrial Applications Center.

  17. Telescope Equipment

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Renaissance Telescope for high resolution and visual astronomy has five 82-degree Field Tele-Vue Nagler Eyepieces, some of the accessories that contribute to high image quality. Telescopes and eyepieces are representative of a family of optical equipment manufactured by Tele-Vue Optics, Inc.

  18. A New Approach to Logging.

    ERIC Educational Resources Information Center

    Miles, Donna

    2001-01-01

    In response to high numbers of preventable fatal accidents in the logging industry, the Occupational Safety and Health Administration (OSHA) developed a week-long logger safety training program that includes hands-on learning of safety techniques in the woods. Reaching small operators has been challenging; outreach initiatives in Maine, North…

  19. CRYPTOSPORIDIUM LOG INACTIVATION CALCULATION METHODS

    EPA Science Inventory

    Appendix O of the Surface Water Treatment Rule (SWTR) Guidance Manual introduces the CeffT10 (i.e., reaction zone outlet C value and T10 time) method for calculating ozone CT value and Giardia and virus log inactivation. The LT2ESWTR Pre-proposal Draft Regulatory Language for St...

  20. Statistical log analysis made practical

    SciTech Connect

    Mitchell, W.K.; Nelson, R.J. )

    1991-06-01

    This paper discusses the advantages of a statistical approach to log analysis. Statistical techniques use inverse methods to calculate formation parameters. The use of statistical techniques has been limited, however, by the complexity of the mathematics and lengthy computer time required to minimize traditionally used nonlinear equations.

  1. 47 CFR 73.781 - Logs.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 4 2010-10-01 2010-10-01 false Logs. 73.781 Section 73.781 Telecommunication... International Broadcast Stations § 73.781 Logs. The licensee or permittee of each international broadcast station must maintain the station log in the following manner: (a) In the program log: (1) An entry of...

  2. 29 CFR 1918.88 - Log operations.

    Code of Federal Regulations, 2010 CFR

    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...

  3. A composite lithology log while drilling

    SciTech Connect

    Tannenbaum, E.; Sutcliffe, B.; Franks, A.

    1988-02-01

    A new method for producing a computerized composite lithology log (CLL) while drilling by integrating MWD (measurement while drilling) and surface data is described. The CLL integrates three types of data (MWD mechanical, MWD geophysical, and surface cuttings) acquired during drilling, in three time stages: (1) Real Time. MWD drilling mechanical data including the rate of penetration and the downhole torque. This stage would provide bed boundaries and some inferred lithology. This would assist the driller with immediate drilling decisions and determine formation tops for coring, casing point, and correlation. (2) MWD Time. Recomputation of the above by adding MWD geophysical data (gamma-ray, resistivity, neutron-density). This stage would upgrade the lithology inference, and give higher resolution of bed boundaries. (3) Lag Time. Detailed analysis of surface cuttings to confirm the inferred lithologies. This last input will result in a high-quality CLL with accurate lithologies and bed boundaries. The log will serve the geologist as well as the driller, petrophysicist, and reservoir engineer. It will form the basis for more comprehensive formation evaluation while drilling by adding hydrocarbon and MWD log data.

  4. Project to transcribe old ship logs provides important weather data

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-11-01

    Kathy Wendolkowski is a citizen scientist. It's a term that Wendolkowski considers far too lofty for what she claims is simply a happy addiction that she and others have for transcribing old logs from naval ship and other vessels. They perform this task to glean the regularly recorded weather data from those logs for the benefit of science. For Wendolkowski, though, greater satisfaction comes from reading what the logs also reveal about the daily lives of the sailors as well as any accompanying historical drama.

  5. Utilizing magnetic resonance imaging logs, openhole logs, and sidewall core analyses to evaluate shaly sands for water-free production

    SciTech Connect

    Taylor, D.A.; Morganti, J.K.; White, H.J. ); Noblett, B.R. )

    1996-01-01

    Nuclear magnetic resonance (NMR) logging using the new C Series Magnetic Resonance Imaging Log (MRIL) system is rapidly enhancing formation evaluation throughout the industry. By measuring irreducible water saturations, permeabilities, and effective porosities, MRIL data can help petrophysicists evaluate low-resistivity pays. In these environments, conventional openhole logs may not define all of the pay intervals. The MRIL system can also reduce the number of unnecessary completions in zones of potentially high water cut. MRIL tool theory and log presentations used with conventional logs and sidewall cores are presented along with field examples. Scanning electron microscope (SEM) analysis shows good correlation of varying grain size in sandstones with the T2 distribution and bulk volume irreducible water determined from the MRIL measurements. Analysis of each new well drilled in the study area shows how water-free production zones were defined. Because the MRIL data were not recorded on one of the wells, predictions from the conventional logs and the MRIL data collected on the other two wells were used to estimate productive zones in the first well. Discussion of additional formation characteristics, completion procedures, actual production, and predicted producibility of the shaly sands is presented. Integrated methodologies resulted in the perforation of 3 new wells for a gross initial potential of 690 BOPD and 0 BWPD.

  6. Utilizing magnetic resonance imaging logs, openhole logs, and sidewall core analyses to evaluate shaly sands for water-free production

    SciTech Connect

    Taylor, D.A.; Morganti, J.K.; White, H.J.; Noblett, B.R.

    1996-12-31

    Nuclear magnetic resonance (NMR) logging using the new C Series Magnetic Resonance Imaging Log (MRIL) system is rapidly enhancing formation evaluation throughout the industry. By measuring irreducible water saturations, permeabilities, and effective porosities, MRIL data can help petrophysicists evaluate low-resistivity pays. In these environments, conventional openhole logs may not define all of the pay intervals. The MRIL system can also reduce the number of unnecessary completions in zones of potentially high water cut. MRIL tool theory and log presentations used with conventional logs and sidewall cores are presented along with field examples. Scanning electron microscope (SEM) analysis shows good correlation of varying grain size in sandstones with the T2 distribution and bulk volume irreducible water determined from the MRIL measurements. Analysis of each new well drilled in the study area shows how water-free production zones were defined. Because the MRIL data were not recorded on one of the wells, predictions from the conventional logs and the MRIL data collected on the other two wells were used to estimate productive zones in the first well. Discussion of additional formation characteristics, completion procedures, actual production, and predicted producibility of the shaly sands is presented. Integrated methodologies resulted in the perforation of 3 new wells for a gross initial potential of 690 BOPD and 0 BWPD.

  7. Logging while fishing technique results in substantial savings

    SciTech Connect

    Tollefsen, E.; Everett, M.

    1996-12-01

    During wireline logging operations, tools occasionally become stuck in the borehole and require fishing. A typical fishing job can take anywhere from 1{1/2}--4 days. In the Gulf of Mexico, a fishing job can easily cost between $100,000 and $500,000. These costs result from nonproductive time during the fishing trip, associated wiper trip and relogging the well. Logging while fishing (LWF) technology is a patented system capable of retrieving a stuck fish and completing the logging run during the same pipe descent. Completing logging operations using LWF method saves time and money. The technique also provides well information where data may not otherwise have been obtained. Other benefits include reduced fishing time and an increased level of safety.

  8. Druzhba feasibility study: Barsukov and Tarasov fields, 1995. Barsukov and Tarasov production histories western equipment. Export trade information

    SciTech Connect

    1996-01-03

    The study, conducted by NEFT, was funded by the U.S. Trade and Development Agency. The report shows the results of a feasibility study conducted for the rehabilitation of oil wells in Baruskov and Tarasov fields. The objectives of the study include a plan for improving well and waterflood performance, and to determine materials and equipment needed. The report also covers capital and operating costs, as well as an evaluation of project economics based on Russian law. This is Volume 2 of the study containing Production Histories-Western Equipment. It is divided into the following sections: (1) Job Descriptions; (2) Barsukov Histories/Logs; (3) Tarasov Histories/Logs; (4) Taxes Paid by PNG; (5) Vendors Literature; (6) Rigs; (7) Liners; (8) Directional Drilling; (9) Mechanical Perforating; (10) Camps; (11) Pumps; (12) Fishing; (13) Downhole Oil/Water Separator; (14) Plastic.

  9. Linking radiology equipment service and medical physics survey databases.

    PubMed

    David, George; Burnett, Lou Ann; Schenkel, Robert

    2004-01-01

    During the performance of medical physics surveys on diagnostic imaging equipment, it is not unusual to find problems requiring service. In the work described in this article, two existing and separate databases, one for radiology equipment maintenance and the other for medical physics surveys were linked. By linking the two databases we have closed the loop in our documentation. The two databases are integrated so that when logging a survey, a single mouse click will allow the user to initiate a service call and link it to the survey. In addition, any survey linked to a service call permits the user to view the service record with a single mouse click. This allows us within the medical physics database to document the resolution of problems as well as to keep track of the status of service calls initiated as a result of medical physics surveys.

  10. Fishing tool retrieves MWD nuclear source from deep well

    SciTech Connect

    Not Available

    1994-01-17

    A new wire line tool has successfully retrieved the nuclear sources and formation data from a measurement-while-drilling (MWD) tool stuck in a deep, highly deviated well in the Gulf of Mexico. On Nov. 8, 1993, Schlumberger Wireline and Testing and Anadrill ran a logging-while-drilling inductive coupling (LINC) tool on conventional wire line to fish the gamma ray and neutron sources from a compensated density neutron (CDN) tool stuck in a well at 19,855 ft with an inclination greater than 80[degree]. The paper briefly describes the operation and equipment.

  11. VAFLE: visual analytics of firewall log events

    NASA Astrophysics Data System (ADS)

    Ghoniem, Mohammad; Shurkhovetskyy, Georgiy; Bahey, Ahmed; Otjacques, Benoît.

    2013-12-01

    In this work, we present VAFLE, an interactive network security visualization prototype for the analysis of firewall log events. Keeping it simple yet effective for analysts, we provide multiple coordinated interactive visualizations augmented with clustering capabilities customized to support anomaly detection and cyber situation awareness. We evaluate the usefulness of the prototype in a use case with network traffic datasets from previous VAST Challenges, illustrating its effectiveness at promoting fast and well-informed decisions. We explain how a security analyst may spot suspicious traffic using VAFLE. We further assess its usefulness through a qualitative evaluation involving network security experts, whose feedback is reported and discussed.

  12. Nonlinear filters with log-homotopy

    NASA Astrophysics Data System (ADS)

    Daum, Fred; Huang, Jim

    2007-09-01

    We derive and test a new nonlinear filter that implements Bayes' rule using an ODE rather than with a pointwise multiplication of two functions. This avoids one of the fundamental and well known problems in particle filters, namely "particle collapse" as a result of Bayes' rule. We use a log-homotopy to construct this ODE. Our new algorithm is vastly superior to the classic particle filter, and we do not use any proposal density supplied by an EKF or UKF or other outside source. This paper was written for normal engineers, who do not have homotopy for breakfast.

  13. Wellhead equipment support

    SciTech Connect

    Nichols, R.P.

    1987-03-24

    A wellhead assembly is described for supporting equipment in a well, comprising: a suspension nut having a threaded outer surface; a wellhead member having an inner threaded surface adapted to mesh with the threaded outer surface of the suspension nut; the suspension nut having a projection extending axially from its threaded outer surface and having an inner surface adapted to support equipment in the well; at least a portion of the inner surface for supporting the equipment facing both inwardly and upwardly such that force exerted by the weight of the equipment against the inner surface is transformed at least in part to a radially outwardly directed force; the projecting having an outer surface sized such that the outer surface is spaced from an inner surface of the wellhead member in the absence of force exerted against the inner surface of the projection such that the projection is deflected outwardly by the force exerted by the weight of the equipment against the inner surface.

  14. 40 CFR 63.1022 - Equipment identification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... may be identified on a plant site plan, in log entries, by designation of process unit or affected... paragraph does not apply to an owner or operator of a batch product process who elects to pressure test the batch product process equipment train pursuant to § 63.1036. (1) Connectors. Except for...

  15. 40 CFR 63.1003 - Equipment identification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... identified on a plant site plan, in log entries, by designation of process unit or affected facility... a group, and the number of connectors subject is indicated. (2) Routed to a process or fuel gas... operator elects to route to a process or fuel gas system or equip with a closed vent system and...

  16. Avian responses to selective logging shaped by species traits and logging practices.

    PubMed

    Burivalova, Zuzana; Lee, Tien Ming; Giam, Xingli; Şekercioğlu, Çağan Hakkı; Wilcove, David S; Koh, Lian Pin

    2015-06-01

    Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as lengthening the rotation cycle and implementing reduced impact logging. PMID:25994673

  17. Avian responses to selective logging shaped by species traits and logging practices.

    PubMed

    Burivalova, Zuzana; Lee, Tien Ming; Giam, Xingli; Şekercioğlu, Çağan Hakkı; Wilcove, David S; Koh, Lian Pin

    2015-06-01

    Selective logging is one of the most common forms of forest use in the tropics. Although the effects of selective logging on biodiversity have been widely studied, there is little agreement on the relationship between life-history traits and tolerance to logging. In this study, we assessed how species traits and logging practices combine to determine species responses to selective logging, based on over 4000 observations of the responses of nearly 1000 bird species to selective logging across the tropics. Our analysis shows that species traits, such as feeding group and body mass, and logging practices, such as time since logging and logging intensity, interact to influence a species' response to logging. Frugivores and insectivores were most adversely affected by logging and declined further with increasing logging intensity. Nectarivores and granivores responded positively to selective logging for the first two decades, after which their abundances decrease below pre-logging levels. Larger species of omnivores and granivores responded more positively to selective logging than smaller species from either feeding group, whereas this effect of body size was reversed for carnivores, herbivores, frugivores and insectivores. Most importantly, species most negatively impacted by selective logging had not recovered approximately 40 years after logging cessation. We conclude that selective timber harvest has the potential to cause large and long-lasting changes in avian biodiversity. However, our results suggest that the impacts can be mitigated to a certain extent through specific forest management strategies such as lengthening the rotation cycle and implementing reduced impact logging.

  18. Data Mining of Network Logs

    NASA Technical Reports Server (NTRS)

    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.

  19. Electromagnetic-induction logging to monitor changing chloride concentrations.

    PubMed

    Metzger, Loren F; Izbicki, John A

    2013-01-01

    Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality-possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

  20. Electromagnetic-induction logging to monitor changing chloride concentrations

    USGS Publications Warehouse

    Metzger, Loren F.; Izbicki, John A.

    2013-01-01

    Water from the San Joaquin Delta, having chloride concentrations up to 3590 mg/L, has intruded fresh water aquifers underlying Stockton, California. Changes in chloride concentrations at depth within these aquifers were evaluated using sequential electromagnetic (EM) induction logs collected during 2004 through 2007 at seven multiple-well sites as deep as 268 m. Sequential EM logging is useful for identifying changes in groundwater quality through polyvinyl chloride-cased wells in intervals not screened by wells. These unscreened intervals represent more than 90% of the aquifer at the sites studied. Sequential EM logging suggested degrading groundwater quality in numerous thin intervals, typically between 1 and 7 m in thickness, especially in the northern part of the study area. Some of these intervals were unscreened by wells, and would not have been identified by traditional groundwater sample collection. Sequential logging also identified intervals with improving water quality—possibly due to groundwater management practices that have limited pumping and promoted artificial recharge. EM resistivity was correlated with chloride concentrations in sampled wells and in water from core material. Natural gamma log data were used to account for the effect of aquifer lithology on EM resistivity. Results of this study show that a sequential EM logging is useful for identifying and monitoring the movement of high-chloride water, having lower salinities and chloride concentrations than sea water, in aquifer intervals not screened by wells, and that increases in chloride in water from wells in the area are consistent with high-chloride water originating from the San Joaquin Delta rather than from the underlying saline aquifer.

  1. 29 CFR 1917.18 - Log handling.

    Code of Federal Regulations, 2010 CFR

    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...

  2. 10 CFR 34.71 - Utilization logs.

    Code of Federal Regulations, 2010 CFR

    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...

  3. 47 CFR 73.1820 - Station log.

    Code of Federal Regulations, 2010 CFR

    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...

  4. 47 CFR 87.109 - Station logs.

    Code of Federal Regulations, 2010 CFR

    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...

  5. Balloon logging with the inverted skyline

    NASA Technical Reports Server (NTRS)

    Mosher, C. F.

    1975-01-01

    There is a gap in aerial logging techniques that has to be filled. The need for a simple, safe, sizeable system has to be developed before aerial logging will become effective and accepted in the logging industry. This paper presents such a system designed on simple principles with realistic cost and ecological benefits.

  6. [Medical Equipment Maintenance Methods].

    PubMed

    Liu, Hongbin

    2015-09-01

    Due to the high technology and the complexity of medical equipment, as well as to the safety and effectiveness, it determines the high requirements of the medical equipment maintenance work. This paper introduces some basic methods of medical instrument maintenance, including fault tree analysis, node method and exclusive method which are the three important methods in the medical equipment maintenance, through using these three methods for the instruments that have circuit drawings, hardware breakdown maintenance can be done easily. And this paper introduces the processing methods of some special fault conditions, in order to reduce little detours in meeting the same problems. Learning is very important for stuff just engaged in this area. PMID:26904890

  7. German mining equipment

    SciTech Connect

    Not Available

    1993-10-01

    The German mining equipment industry developed to supply machines and services to the local mining industry, i.e., coal, lignite, salt, potash, ore mining, industrial minerals, and quarrying. The sophistication and reliability of its technology also won it worldwide export markets -- which is just as well since former major domestic mining sectors such as coal and potash have declined precipitously, and others such as ore mining have all but disappeared. Today, German mining equipment suppliers focus strongly on export sales, and formerly unique German mining technologies such as continuous mining with bucket wheel excavators and conveyors for open pits, or plowing of underground coal longwalls are widely used abroad. The status of the German mining equipment industry is reviewed.

  8. Latent log-linear models for handwritten digit classification.

    PubMed

    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.

  9. High-Resolution Flow Logging for Hydraulic Characterization of Boreholes and Aquifer Flow Zones at Contaminated Bedrock Sites

    NASA Astrophysics Data System (ADS)

    Williams, J. H.; Johnson, C. D.; Paillet, F. L.

    2004-05-01

    In the past, flow logging was largely restricted to the application of spinner flowmeters to determine flow-zone contributions in large-diameter production wells screened in highly transmissive aquifers. Development and refinement of tool-measurement technology, field methods, and analysis techniques has greatly extended and enhanced flow logging to include the hydraulic characterization of boreholes and aquifer flow zones at contaminated bedrock sites. State-of-the-art in flow logging will be reviewed, and its application to bedrock-contamination investigations will be presented. In open bedrock boreholes, vertical flows are measured with high-resolution flowmeters equipped with flexible rubber-disk diverters fitted to the nominal borehole diameters to concentrate flow through the measurement throat of the tools. Heat-pulse flowmeters measure flows in the range of 0.05 to 5 liters per minute, and electromagnetic flowmeters measure flows in the range of 0.3 to 30 liters per minute. Under ambient and low-rate stressed (either extraction or injection) conditions, stationary flowmeter measurements are collected in competent sections of the borehole between fracture zones identified on borehole-wall images. Continuous flow, fluid-resistivity, and temperature logs are collected under both sets of conditions while trolling with a combination electromagnetic flowmeter and fluid tool. Electromagnetic flowmeters are used with underfit diverters to measure flow rates greater than 30 liters per minute and suppress effects of diameter variations while trolling. A series of corrections are applied to the flow-log data to account for the zero-flow response, bypass, trolling, and borehole-diameter biases and effects. The flow logs are quantitatively analyzed by matching simulated flows computed with a numerical model to measured flows by varying the hydraulic properties (transmissivity and hydraulic head) of the flow zones. Several case studies will be presented that demonstrate

  10. Detection, diagnosis, and prognosis in geothermal well technology

    SciTech Connect

    Veneruso, A.F.; Chang, H.T.

    1980-01-01

    For successful and safe operation of a geothermal well, the condition of the casing and cement must be accurately determined. Measurements on casing wall thickness, corrosion damage, holes, cracks, splits, etc., are needed to assess casing integrity. Cement bond logs are needed to detect channels or water pockets in cement behind pipe and to determine the state of the cement bond to the pipe and formation. Instrumentation for making such measurements is limited by the temperature capabilities (<175/sup 0/C) of existing logging equipment developed for the oil and gas industry. The instruments that are needed for geothermal casing and cementing inspection are reviewed; the principle deficiencies in their high temperature use are identified; and Sandia's upgrade research program on multi-arm caliper and acoustic cement bond logging tool is described. The key electronic section in a multi-arm caliper will consist of 275/sup 0/C circuits. In an acoustic cement bond logging tool, a simple circuit with possibilities of using commercially available components for high temperature operation is being developed. These new tools will be field tested for operation at a minimum temperature of 275/sup 0/C and pressure of 7000 psi for up to 1000 hours.

  11. Dual excitation acoustic paramagnetic logging tool

    DOEpatents

    Vail, III, William B.

    1989-01-01

    New methods and apparatus are disclosed which allow measurement of the presence of oil and water in gelogical formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleous present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be preformed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described.

  12. Dewarless Logging Tool - 1st Generation

    SciTech Connect

    HENFLING,JOSEPH A.; NORMANN,RANDY A.

    2000-08-01

    This report focuses on Sandia National Laboratories' effort to create high-temperature logging tools for geothermal applications without the need for heat shielding. One of the mechanisms for failure in conventional downhole tools is temperature. They can only survive a limited number of hours in high temperature environments. For the first time since the evolution of integrated circuits, components are now commercially available that are qualified to 225 C with many continuing to work up to 300 C. These components are primarily based on Silicon-On-Insulator (SOI) technology. Sandia has developed and tested a simple data logger based on this technology that operates up to 300 C with a few limiting components operating to only 250 C without thermal protection. An actual well log to 240 C without shielding is discussed. The first prototype high-temperature tool measures pressure and temperature using a wire-line for power and communication. The tool is based around the HT83C51 microcontroller. A brief discussion of the background and status of the High Temperature Instrumentation program at Sandia, objectives, data logger development, and future project plans are given.

  13. Dual excitation acoustic paramagnetic logging tool

    DOEpatents

    Vail, W.B. III.

    1989-02-14

    New methods and apparatus are disclosed which allow measurement of the presence of oil and water in geological formations using a new physical effect called the Acoustic Paramagnetic Logging Effect (APLE). The presence of petroleum in formation causes a slight increase in the earth's magnetic field in the vicinity of the reservoir. This is the phenomena of paramagnetism. Application of an acoustic source to a geological formation at the Larmor frequency of the nucleons present causes the paramagnetism of the formation to disappear. This results in a decrease in the earth's magnetic field in the vicinity of the oil bearing formation. Repetitively frequency sweeping the acoustic source through the Larmor frequency of the nucleons present (approx. 2 kHz) causes an amplitude modulation of the earth's magnetic field which is a consequence of the APLE. The amplitude modulation of the earth's magnetic field is measured with an induction coil gradiometer and provides a direct measure of the amount of oil and water in the excitation zone of the formation. The phase of the signal is used to infer the longitudinal relaxation times of the fluids present, which results in the ability in general to separate oil and water and to measure the viscosity of the oil present. Such measurements may be performed in open boreholes and in cased well bores. The Dual Excitation Acoustic Paramagnetic Logging Tool employing two acoustic sources is also described. 6 figs.

  14. Ice logging with light and sound

    NASA Astrophysics Data System (ADS)

    Bay, Ryan C.; Bramall, Nathan; Price, P. Buford

    Polar ice may well be the purest solid substance on Earth, and yet the impurities it contains—gases, dust, and micro-organisms—provide a rich record of Earth's past climate, volcanism, and one-celled life going back ˜400,000 years. Until recently detailed records had been deciphered mostly in chemical and biological laboratories from meter-long ice cores removed by drills capable of coring to bedrock thousands of meters down. Now, borehole instruments are adding a new dimension to the study of ice sheets. They can rapidly log records of past climate, volcanism, c-axis ice fabric, and soon, even microbial life and grain size. Gary Clow, a pioneer in borehole logging, has been measuring temperature profiles that provide information on climate and ice flow [Dahl-Jensen et al., 1998]. From sonic velocity profiles, Kendrick Taylor and Gregg Lamorey are able to infer c-axis fabrics, which record the history of ice flow Robert Hawley and Ed Waddington have developed a video logger that detects annual layers in firn ice.

  15. New Mexico Play Fairway Analysis: Gamma Ray Logs and Heat Generation Calculations for SW New Mexico

    SciTech Connect

    Shari Kelley

    2015-10-23

    For the New Mexico Play fairway Analysis project, gamma ray geophysical well logs from oil wells penetrating the Proterozoic basement in southwestern New Mexico were digitized. Only the portion of the log in the basement was digitized. The gamma ray logs are converted to heat production using the equation (Bucker and Rybach, 1996) : A[µW/m3] = 0.0158 (Gamma Ray [API] – 0.8).

  16. Logs Wanted - Dead or Alive

    NASA Astrophysics Data System (ADS)

    Schuchardt, A.; Morche, D.

    2015-12-01

    Rivers cover only a small part of the Earth`s surface, yet they transfer sediment in globally significant quantities. In mountainous regions, the majority of the total channel length occurs in headwater streams. Those mountain channels are influenced in terms of sediment connectivity by processes on the slopes. For example in such a sediment routing system, sediment originating from debris flows on the slopes is delivered along sediment pathways to the channel system and can be transported further downstream as solid load. Interruption of instream coarse sediment connectivity is closely related to the existence of channel blocking barriers which also can be formed by biota. By storing sediment large wood (LW) log jams disrupt in-channel sediment connectivity. We present a study design in order to decipher the short to long term effects (c. 10-2-102 years) of sediment (dis)connectivity effects of large wood. The study areas are two basins in mountain ranges in Germany and Austria. In Austria the drainage area of the river Fugnitz was chosen which is located in the National Park Thayatal. The other drainage area of the river Sieber in Saxony-Anhalt, Germany, is located in the Harz National Park. Since studies on LW and its geomorphological effects in Central European rivers are still rare the main goals of the project are: •to identify important triggers for LW transport from slopes into the channels •to examine the spatial distribution and characterization of LW in main and slope channels by mapping and dGPS measurements •to determine the effects of LW on channel hydraulic parameters (e.g. slope, width, grains size composition, roughness) by field measurements of channel long profiles and cross section with dGPS and Wolman particle counts •to quantify the direct effects of LW on discharge and bed load transport by measuring flow velocity with an Ott-Nautilus current meter and to measure bed load up- and downstream of log jams using a portable Helley

  17. Determining Partition Coefficient (Log P), Distribution Coefficient (Log D) and Ionization Constant (pKa) in Early Drug Discovery.

    PubMed

    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.

  18. Determining Partition Coefficient (Log P), Distribution Coefficient (Log D) and Ionization Constant (pKa) in Early Drug Discovery.

    PubMed

    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. PMID:27137915

  19. Tracking log displacement during floods in the Tagliamento River using RFID and GPS tracker devices

    NASA Astrophysics Data System (ADS)

    Ravazzolo, D.; Mao, L.; Picco, L.; Lenzi, M. A.

    2015-01-01

    Large pieces of in-channel wood can exert an important role on the ecological and morphological properties of gravel-bed rivers. On the other side, when transported during flood events, large wood can become a source of risk for sensitive structures such as bridges. However, wood displacement and velocity in river systems are still poorly understood, especially in large gravel-bed rivers. This study focuses on log transport in a valley reach of Tagliamento River (Italy). Log displacement during flood events of different magnitudes recorded from June 2010 to October 2011 has been analysed thanks to the installation of 113 radio frequency identification (RFID) tags and 42 GPS tracker devices in logs of different dimensions. Recovery rates of logs equipped with RFID and GPS trackers were about 43% and 42%, respectively. The GPS devices allowed us to analyse in details the log displacement and transport overtime, indicating a higher log entrainment during rising limb of hydrographs. The threshold for the entrainment of logs from low bars is around 40% of bankfull water stage. No clear relationship was found between the peak of flood and log displacement length and velocity. However, log displacement length and velocity appear significantly correlated to the ratio between the peak of flow and the water stage exceeding the flow duration curve for 25% of time (i.e. the ratio hmax/h25 ratio). Log deposition was observed to occur at the peak flow, and logs transported during ordinary events are preferably deposited on low bars. This study reveals the potentials of GPS tracker devices to monitor the entrainment and movements of logs in large gravel-bed rivers during floods. These observations could be useful for better planning of river management practices and strategies involving the use of large wood pieces and could help for calibrating wood budgets at the reach scale.

  20. Leak checker data logging system

    SciTech Connect

    Payne, J.J.; Gannon, J.C.

    1994-12-31

    A portable, high speed, computer-based data logging system for field testing systems or components located some distance apart employs a plurality of spaced mass spectrometers and is particularly adapted for monitoring the vacuum integrity of a long string of a superconducting magnets such as used in high energy particle accelerators. The system provides precise tracking of a gas such as helium through the magnet string when the helium is released into the vacuum by monitoring the spaced mass spectrometers allowing for control, display and storage of various parameters involved with leak detection and localization. A system user can observe the flow of helium through the magnet string on a real-time basis hour the exact moment of opening of the helium input valve. Graph reading can be normalized to compensate for magnet sections that deplete vacuum faster than other sections between testing to permit repetitive testing of vacuum integrity in reduced time.

  1. Leak checker data logging system

    DOEpatents

    Gannon, J.C.; Payne, J.J.

    1996-09-03

    A portable, high speed, computer-based data logging system for field testing systems or components located some distance apart employs a plurality of spaced mass spectrometers and is particularly adapted for monitoring the vacuum integrity of a long string of a superconducting magnets such as used in high energy particle accelerators. The system provides precise tracking of a gas such as helium through the magnet string when the helium is released into the vacuum by monitoring the spaced mass spectrometers allowing for control, display and storage of various parameters involved with leak detection and localization. A system user can observe the flow of helium through the magnet string on a real-time basis hour the exact moment of opening of the helium input valve. Graph reading can be normalized to compensate for magnet sections that deplete vacuum faster than other sections between testing to permit repetitive testing of vacuum integrity in reduced time. 18 figs.

  2. Leak checker data logging system

    DOEpatents

    Gannon, Jeffrey C.; Payne, John J.

    1996-01-01

    A portable, high speed, computer-based data logging system for field testing systems or components located some distance apart employs a plurality of spaced mass spectrometers and is particularly adapted for monitoring the vacuum integrity of a long string of a superconducting magnets such as used in high energy particle accelerators. The system provides precise tracking of a gas such as helium through the magnet string when the helium is released into the vacuum by monitoring the spaced mass spectrometers allowing for control, display and storage of various parameters involved with leak detection and localization. A system user can observe the flow of helium through the magnet string on a real-time basis hour the exact moment of opening of the helium input valve. Graph reading can be normalized to compensate for magnet sections that deplete vacuum faster than other sections between testing to permit repetitive testing of vacuum integrity in reduced time.

  3. Aquatic Equipment Information.

    ERIC Educational Resources Information Center

    Sova, Ruth

    Equipment usually used in water exercise programs is designed for variety, intensity, and program necessity. This guide discusses aquatic equipment under the following headings: (1) equipment design; (2) equipment principles; (3) precautions and contraindications; (4) population contraindications; and (5) choosing equipment. Equipment is used…

  4. Correlating Log Messages for System Diagnostics

    SciTech Connect

    Gunasekaran, Raghul; Dillow, David A; Shipman, Galen M; Maxwell, Don E; Hill, Jason J; Park, Byung H; Geist, Al

    2010-01-01

    In large-scale computing systems, the sheer volume of log data generated presents daunting challenges for debugging and monitoring of these systems. The Oak Ridge Leadership Computing Facility s premier simulation platform, the Cray XT5 known as Jaguar, can generate a few hundred thousand log entries in less than a minute for many system level events. Determining the root cause of such system events requires analyzing and interpretation of a large number of log messages. Most often, the log messages are best understood when they are interpreted collectively rather than individually. In this paper, we present our approach to interpreting log messages by identifying their commonalities and grouping them into clusters. Given a set of log messages within a time interval, we group the messages based on source, target, and/or error type, and correlate the messages with hardware and application information. We monitor the Lustre log messages in the XT5 console log and show that such grouping of log messages assists in detecting the source of system events. By intelligent grouping and correlation of events in the log, we are able to provide system administrators with meaningful information in a concise format for root cause analysis.

  5. Tolerance bounds for log gamma regression models

    NASA Technical Reports Server (NTRS)

    Jones, R. A.; Scholz, F. W.; Ossiander, M.; Shorack, G. R.

    1985-01-01

    The present procedure for finding lower confidence bounds for the quantiles of Weibull populations, on the basis of the solution of a quadratic equation, is more accurate than current Monte Carlo tables and extends to any location-scale family. It is shown that this method is accurate for all members of the log gamma(K) family, where K = 1/2 to infinity, and works well for censored data, while also extending to regression data. An even more accurate procedure involving an approximation to the Lawless (1982) conditional procedure, with numerical integrations whose tables are independent of the data, is also presented. These methods are applied to the case of failure strengths of ceramic specimens from each of three billets of Si3N4, which have undergone flexural strength testing.

  6. Flow rate logging seepage meter

    NASA Technical Reports Server (NTRS)

    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.

  7. NADIR: Monitoring, Error Handling, and Logging with Tango

    NASA Astrophysics Data System (ADS)

    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.

  8. Optimal message log reclamation for independent checkpointing

    NASA Technical Reports Server (NTRS)

    Wang, Yi-Min; Fuchs, W. Kent

    1993-01-01

    Independent (uncoordinated) check pointing for parallel and distributed systems allows maximum process autonomy but suffers from possible domino effects and the associated storage space overhead for maintaining multiple checkpoints and message logs. In most research on check pointing and recovery, it was assumed that only the checkpoints and message logs older than the global recovery line can be discarded. It is shown how recovery line transformation and decomposition can be applied to the problem of efficiently identifying all discardable message logs, thereby achieving optimal garbage collection. Communication trace-driven simulation for several parallel programs is used to show the benefits of the proposed algorithm for message log reclamation.

  9. Robust Audio Watermarking Based on Log-Polar Frequency Index

    NASA Astrophysics Data System (ADS)

    Yang, Rui; Kang, Xiangui; Huang, Jiwu

    In this paper, we analyze the audio signal distortions introduced by pitch-scaling, random cropping and DA/AD conversion, and find a robust feature, average Fourier magnitude over the log-polar frequency index(AFM), which can resist these attacks. Theoretical analysis and extensive experiments demonstrate that AFM is an appropriate embedding region for robust audio watermarking. This is the first work on applying log-polar mapping to audio watermark. The usage of log-polar mapping in our work is basically different from the existing works in image watermarking. The log-polar mapping is only applied to the frequency index, not to the transform coefficients, which avoids the reconstruction distortion of inverse log-polar transform and reduces the computation cost. Comparison with the existing methods, the proposed AFM-based watermarking scheme has the outstanding performance on resisting pitch-scaling and random cropping, as well as very approving robustness to DA/AD conversion and TSM (Time-Scale Modification). The watermarked audio achieves high auditory quality. Experimental results show that the scheme is very robust to common audio signal processing and distortions introduced in Stirmark for Audio.

  10. Log-Derived evaluation of shaly sandstone reservoirs

    SciTech Connect

    Fertl, W.H.

    1984-04-01

    Significant natural gas resources are known to exist in the United States in tight, low-permeability sandstones that cover a prospective area of 1,000,000 mi/sup 2/ (2,590,000 km/sup 2/). Characterization and reliable estimation of their production potential based on well logs are important although difficult task. Proper evaluation of low permeability sands based on conventional log-interpretation techniques is frequently inadequate. Furthermore, while empirical rules of thumb assist in the evaluation of localized conditions, they only provide guidelines. Recent developments in quantitative log-analysis techniques incorporate natural-gamma-ray spectral data and application of the Waxman-Smits model for detailed reservoir description. Quantitative correlations of cation exchange capacity (CEC), water salinity, porosity, and conductivity of water- and hydrocarbon-bearing shaly sand reservoirs are based on resistivity, density, neutron and natural-gamma-ray spectral data. These correlations provide important information about clay volume, reservoir porosities (total, effective) and fluid-saturation distribution (total, effective), type of clay minerals (smectite, illite, chlorite/kaolinite), their distribution in the reservoir (dispersed, laminated, structural), and log-derived indicators of potential formation damage. Field experiences are reviewed for logging and evaluating tight formations in south Texas; the Jurassic Cotton Valley trend in east Texas, Louisiana, and Arkansas; and the Tertiary Fort Union and Cretaceous Mesaverde Formations of the Piceance basin in Colorado.

  11. CosmicEmuLog: Cosmological Power Spectra Emulator

    NASA Astrophysics Data System (ADS)

    Neyrinck, Mark

    2013-04-01

    CosmicEmuLog is a simple Python emulator for cosmological power spectra. In addition to the power spectrum of the conventional overdensity field, it emulates the power spectra of the log-density as well as the Gaussianized density. It models fluctuations in the power spectrum at each k as a linear combination of contributions from fluctuations in each cosmological parameter. The data it uses for emulation consist of ASCII files of the mean power spectrum, together with derivatives of the power spectrum with respect to the five cosmological parameters in the space spanned by the Coyote Universe suite. This data can also be used for Fisher matrix analysis. At present, CosmicEmuLog is restricted to redshift 0.

  12. Learning Logs in Introductory Literature Courses

    ERIC Educational Resources Information Center

    Babcock, Matthew James

    2007-01-01

    This article explores the beneficial and sometimes unpredictable implications of a daily reflective writing exercise for introductory literature courses: the learning log. Pseudonymous samples of student writing, coupled with instructor commentary, gesture toward ways in which the learning log's continual implementation and modification foster a…

  13. Chernoff's density is log-concave.

    PubMed

    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.

  14. Measuring Reading Instruction with Teacher Logs

    ERIC Educational Resources Information Center

    Rowan, Brian; Correnti, Richard

    2009-01-01

    The authors argue that the criticisms of their earlier article on teacher logs ("Educational Researcher," March 2009) by Smagorinsky and Willis do not address, much less undermine, the evidence they presented as part of their validation argument about the teacher logs. Moreover, they argue that their method for studying classrooms is not nearly as…

  15. 10 CFR 34.71 - Utilization logs.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Utilization logs. 34.71 Section 34.71 Energy NUCLEAR REGULATORY COMMISSION LICENSES FOR INDUSTRIAL RADIOGRAPHY AND RADIATION SAFETY REQUIREMENTS FOR INDUSTRIAL RADIOGRAPHIC OPERATIONS Recordkeeping Requirements § 34.71 Utilization logs. (a) Each licensee shall...

  16. Discover Presidential Log Cabins. Teacher's Discussion Guide.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC.

    Discover Presidential Log Cabins is a set of materials designed to help educate 6-8 grade students about the significance of three log cabin sites occupied by George Washington, Ulysses Grant, Abraham Lincoln, and Theodore Roosevelt. This teacher's discussion guide is intended for use as part of a larger, comprehensive social studies program, and…

  17. 40 CFR 90.412 - Data logging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Data logging. 90.412 Section 90.412....412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data...

  18. 40 CFR 90.412 - Data logging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Data logging. 90.412 Section 90.412....412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data...

  19. 40 CFR 89.409 - Data logging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Data logging. 89.409 Section 89.409... Data logging. (a) A computer or any other automatic data processing device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data collection records...

  20. 40 CFR 91.412 - Data logging.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Data logging. 91.412 Section 91.412... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets...

  1. 40 CFR 91.412 - Data logging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Data logging. 91.412 Section 91.412... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets...

  2. 40 CFR 90.412 - Data logging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 90.412 Section 90.412....412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data...

  3. 40 CFR 89.409 - Data logging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 89.409 Section 89.409... Data logging. (a) A computer or any other automatic data processing device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data collection records...

  4. 40 CFR 89.409 - Data logging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Data logging. 89.409 Section 89.409... Data logging. (a) A computer or any other automatic data processing device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data collection records...

  5. 40 CFR 89.409 - Data logging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Data logging. 89.409 Section 89.409... Data logging. (a) A computer or any other automatic data processing device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data collection records...

  6. 40 CFR 90.412 - Data logging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Data logging. 90.412 Section 90.412....412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data...

  7. 40 CFR 90.412 - Data logging.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Data logging. 90.412 Section 90.412....412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data...

  8. 40 CFR 91.412 - Data logging.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Data logging. 91.412 Section 91.412... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets...

  9. 40 CFR 89.409 - Data logging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Data logging. 89.409 Section 89.409... Data logging. (a) A computer or any other automatic data processing device(s) may be used as long as the system meets the requirements of this subpart. (b) Determine from the data collection records...

  10. 40 CFR 91.412 - Data logging.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Data logging. 91.412 Section 91.412... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets...

  11. 40 CFR 91.412 - Data logging.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 20 2014-07-01 2013-07-01 true Data logging. 91.412 Section 91.412... EMISSIONS FROM MARINE SPARK-IGNITION ENGINES Gaseous Exhaust Test Procedures § 91.412 Data logging. (a) A computer or any other automatic data collection (ADC) device(s) may be used as long as the system meets...

  12. Logging technology for high-temperature geothermal boreholes

    SciTech Connect

    Dennis, B.R.

    1984-05-01

    Research in materials, equipment, and instrument development was required in the Hot Dry Rock Energy Extraction Demonstration at Fenton Hill located in northern New Mexico. Results of this extensive development advanced the logging technology in geothermal boreholes to present state-of-the art. The new Phase II Energy Extraction System at the Fenton Hill Test Site will consist of two wellbores drilled to a depth of about 4570 m (15,000 ft) and then connected by a series of hydraulic-induced fractures. The first borehole (EE-2) was completed in May of 1980 at a depth of 4633 m (15,200 ft) of which approximately 3960 m (13,000 ft) is in Precambrian granitic rock. Starting at a depth of approximately 2930 m (9600 ft), the borehole was inclined up to 35/sup 0/ from vertical. Bottom-hole temperature in EE-2 is 320/sup 0/C. The EE-3 borehole was then drilled to a depth of 4236 m (13,900 ft). Its inclined part is positioned directly over the EE-2 wellbore with a vertical separation of about 450 m (1500 ft) between them. Many of the geophysical measurements needed to develop the hot dry rock concept are unique. Most of the routine instruments used in petroleum drilling fail in the hot and abrasive environment. New equipment developed includes not only the downhole sonde that houses the transducer and associated line driving electronics, but modifications also were needed on the entire data retrieval systems and associated data analysis technology. Successful performance of wellbore surveys in the EE-2 and EE-3 boreholes depended upon the capacity of the sensors, instrument sonde, cablehead, and armored logging cable to work in this severe environment. The major areas of materials development for surveying the boreholes in the high-temperature environment were on elastomeric seals, electrical insulation for logging cables, downhole sensors, and associated downhole electronic and electro-mechanical components.

  13. Coal-log pipeline system development

    SciTech Connect

    Liu, H.

    1991-12-01

    Project tasks include: (1) Perform the necessary testing and development to demonstrate that the amount of binder in coal logs can be reduced to 8% or lower to produce logs with adequate strength to eliminate breakage during pipeline transportation, under conditions experienced in long distance pipeline systems. Prior to conducting any testing and demonstration, grantee shall perform an information search and make full determination of all previous attempts to extrude or briquette coal, upon which the testing and demonstration shall be based. (2) Perform the necessary development to demonstrate a small model of the most promising injection system for coal-logs, and tests the logs produced. (3) Conduct economic analysis of coal-log pipeline, based upon the work to date. Refine and complete the economic model. (VC)

  14. Designing and Piloting a Leadership Daily Practice Log: Using Logs to Study the Practice of Leadership

    ERIC Educational Resources Information Center

    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…

  15. Breaking the vicious circle of illegal logging in Indonesia.

    PubMed

    Linkie, Matthew; Sloan, Sean; Kasia, Rahmad; Kiswayadi, Dedy; Azmi, Wahdi

    2014-08-01

    The government of Indonesia, which presides over 10% of the world's tropical forests, has set ambitious targets to cut its high deforestation rates through an REDD+ scheme (Reducing Emissions from Deforestation and forest Degradation). This will require strong law enforcement to succeed. Yet, strategies that have accomplished this are rare and, along with past failures, tend not to be documented. We evaluated a multistakeholder approach that seeks to tackle illegal logging in the carbon-rich province of Aceh, Sumatra. From 2008 to 2009, Fauna & Flora International established and supported a community-based informant network for the 738,000 ha Ulu Masen ecosystem. The network reported 190 forest offenses to local law enforcement agencies, which responded with 86 field operations that confiscated illicit vehicles, equipment, and timber, and arrested 138 illegal logging suspects. From 45 cases subsequently monitored, 64.4% proceeded to court, from which 90.0% of defendants received a prison sentence or a verbal warning for a first offense. Spatial analyses of illegal logging and timber storage incidents predicted that illegal activities would be more effectively deterred by law enforcement operations that targeted the storage sites. Although numerous clusters of incidents were identified, they were still widespread reflecting the ubiquity of illegal activities. The multistakeholder results were promising, but illegal logging still persisted at apparently similar levels at the project's end, indicating that efforts need to be further strengthened. Nevertheless, several actions contributed to the law enforcement achievements: strong political will; strong stakeholder support; and funding that could be promptly accessed. These factors are highlighted as prerequisites for achieving Indonesia's ambitious REDD+ goals.

  16. Breaking the vicious circle of illegal logging in Indonesia.

    PubMed

    Linkie, Matthew; Sloan, Sean; Kasia, Rahmad; Kiswayadi, Dedy; Azmi, Wahdi

    2014-08-01

    The government of Indonesia, which presides over 10% of the world's tropical forests, has set ambitious targets to cut its high deforestation rates through an REDD+ scheme (Reducing Emissions from Deforestation and forest Degradation). This will require strong law enforcement to succeed. Yet, strategies that have accomplished this are rare and, along with past failures, tend not to be documented. We evaluated a multistakeholder approach that seeks to tackle illegal logging in the carbon-rich province of Aceh, Sumatra. From 2008 to 2009, Fauna & Flora International established and supported a community-based informant network for the 738,000 ha Ulu Masen ecosystem. The network reported 190 forest offenses to local law enforcement agencies, which responded with 86 field operations that confiscated illicit vehicles, equipment, and timber, and arrested 138 illegal logging suspects. From 45 cases subsequently monitored, 64.4% proceeded to court, from which 90.0% of defendants received a prison sentence or a verbal warning for a first offense. Spatial analyses of illegal logging and timber storage incidents predicted that illegal activities would be more effectively deterred by law enforcement operations that targeted the storage sites. Although numerous clusters of incidents were identified, they were still widespread reflecting the ubiquity of illegal activities. The multistakeholder results were promising, but illegal logging still persisted at apparently similar levels at the project's end, indicating that efforts need to be further strengthened. Nevertheless, several actions contributed to the law enforcement achievements: strong political will; strong stakeholder support; and funding that could be promptly accessed. These factors are highlighted as prerequisites for achieving Indonesia's ambitious REDD+ goals. PMID:24628366

  17. Experimental drill hole logging in potash deposits of the Carlsbad district, New Mexico

    USGS Publications Warehouse

    Jones, C.L.; Bowles, C. Gilbert; Bell, Kenneth Granville

    1960-01-01

    Experimental logging of holes drilled through potash deposits in the Carlsbad district, southeastern New Mexico, demonstrate the considerable utility of gamma-ray, neutron, and electrical resistivity logging in the search for and identification of mineable deposits of sylvite and langbeinite. Such deposits are strongly radioactive with both gamma-ray and neutron well logging. Their radlioactivity serves to distinguish them from claystone, sandstone, and polyhalite beds and from potash deposits containing carnallite, leonite, and kainite. These latter strata and deposits are radioactive with gamma-ray logging but yield no radiation with neutron logging. Porous beds, such as sandstone strata, and solution cavities, such as those commonly formed in potash deposits by rotary drilling of evaporites, are less resistive than other materials. Low resistivity provides a means for differentiating between potash deposits and polyhalite beds on electrical resistivity logs of holes drilled with fresh-water and salt-base muds.

  18. Satellite technology applied at the well site

    SciTech Connect

    Linger, D.B.; Dill, P.H.

    1988-01-01

    The full potential of satellite technology is making itself known in the oil field. Well site data can be sent directly to the operator giving fast, cost-saving answers. Direct linkage from the field to the operator and to computing resources represents a radical change in existing methods of handling well site data. One system, developed by Schlumberger, employs satellite technology to handle well site log data. The service, called Lognet, uses a small transportable earth station at the well site to provide a high speed data and voice link from the well site, via satellite, to the operator, his partners, or to any of the well logging company's offices. The system can deliver both well log graphics and digital taped data to an appropriate receiving terminal, allowing up to 10 delivery points to receive the information simultaneously. Delivery to standard office or portable facsimile machines permits direct reception of logs at the office or any other location. This capability allows the operator and his partners to view the log information within 1 hour after logging and to discuss the log results. Voice communication also is possible with telephone calls being made both to and from the logging unit to any point in the public telephone network. These capabilities result in a more efficient use of staff, information, time, and ultimately, cost savings.

  19. Computer-aided lithostratigraphic correlation using E-logs

    SciTech Connect

    Fang, J.H.; Chen, H.C.; Shultz, A.W.; Mahmoud, W. )

    1991-03-01

    Various attempts have been made in recent years toward computer-assisted well-log correlation in hopes of removing subjectivity which is inherent in manual correlation. However, this application of computer technology has achieved only limited success and popularity among geologists, due partly to the use of nongeologic jargon describing machine correlation and partly due to the publication of these papers in journals seldom read by geologists. The authors have coded a computer program which performs machine correlation, allowing human intervention at several stages. First, the interval to be correlated is segmented (by machine or manually) into zones, then the four attributes (depth, thickness, log amplitude, and log shape) of each zone are used to perform matching. In essence, this is a pattern recognition approach, but not by comparing just one feature at a time, but by considering all attributes jointly and simultaneously in a 'gestalt' manner. The program starts by digitizing logs, smoothing log signatures, and carrying out zonation between marker beds. Preliminary marker beds are either predetermined by the geologist, or are the result of iterative matching. For each pair of zones in two different wells, a difference is computed by comparing strings of attributes. In this manner, each pair of wells produces a difference matrix with one cell for each combination of zones. Dynamic programming is then used to trace the path of minimum total difference, designated by a P-matrix. These P-matrices may reveal certain geologic structures which are helpful not just in correlation but also in structural interpretation.

  20. Magnetic logging: Detection of the earth's magnetic field reversals and application to borehole magnetostratigraphy

    SciTech Connect

    Bouisset, P.; Lalanne, B.; Augustin, A. ); Pages, G. )

    1991-03-01

    TOTAL CFP and CEA (the French Atomic Energy Commission) designed and developed two magnetic logging tools for precise and reliable in-situ magnetic measurements in the low magnetized sedimentary formations encountered when drilling for oil. The tools, measuring respectively the magnetic field and the magnetic susceptibility of the rocks, are operated as standard logging tools, and logs are recorded during standard logging operations. A proper combination of these magnetic respectively the magnetic field and the magnetic susceptibility of the rocks, are operated as standard logging tools, and logs are recorded during standard logging operations. A proper combination of these magnetic measurements leads to the determination, every meter, of natural remanent magnetization polarity, from which the direction of the Earth's magnetic field at the time of sedimentation is derived. A magnetostratigraphic sequence is obtained for each well and appears to be similar to the magnetostratigraphic reference scale. Application of this method to wells in the North Sea gives good results for correlations and absolute age determination, as well as facies diachronism. Further comparison of results obtained from magnetic measurements and from sequence stratigraphy applied to conventional logs shows that third-order sequence boundaries can be diachronous in wells 80 km apart. Although the potential of magnetic measurements is still under investigation, the first encouraging results clearly show that the new dating method presented in this paper can be very helpful in petroleum geology.

  1. Multiple populations on the horizontal branch. I - Observations in the (log g, log T/eff/)-diagram

    NASA Technical Reports Server (NTRS)

    Crocker, Deborah A.; Rood, Robert T.; O'Connell, Robert W.

    1988-01-01

    Log T(eff) and log g have been determined for blue horizontal branch (HB) stars in the globular clusters M15, M3, M5, M92, and NGC 288 as a first step in determining the physical origin of gaps or bimodal distributions in the blue horizontal branches of a number of globular clusters. The (log g, log T/eff/) diagram for the 'normal' HB cluster M5 matches the standard theory quite well. The stars blueward of the gap in NGC 288 and the blue extension of the M3 HB have significantly lower gravity than predicted by the standard theory. The cooler stars in M3 agree well with the standard theory while those of NGC 2988 lie at slightly lower gravity. In M92, the sequence of stars is broadened toward the low gravity side more than expected either from standard evolution or from observational error. The data for M15 are too scattered to support firm conclusions but seem consistent with NGC 288.

  2. Recognizing Patterns In Log-Polar Coordinates

    NASA Technical Reports Server (NTRS)

    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.

  3. Nonblocking and orphan free message logging protocols

    NASA Technical Reports Server (NTRS)

    Alvisi, Lorenzo; Hoppe, Bruce; Marzullo, Keith

    1992-01-01

    Currently existing message logging protocols demonstrate a classic pessimistic vs. optimistic tradeoff. We show that the optimistic-pessimistic tradeoff is not inherent to the problem of message logging. We construct a message-logging protocol that has the positive features of both optimistic and pessimistic protocol: our protocol prevents orphans and allows simple failure recovery; however, it requires no blocking in failure-free runs. Furthermore, this protocol does not introduce any additional message overhead as compared to one implemented for a system in which messages may be lost but processes do not crash.

  4. Efficient Preprocessing technique using Web log mining

    NASA Astrophysics Data System (ADS)

    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.

  5. A small-diameter NMR logging tool for groundwater investigations.

    PubMed

    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. PMID:23425428

  6. Logging-while-coring method and apparatus

    DOEpatents

    Goldberg, David S.; Myers, Gregory J.

    2007-01-30

    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.

  7. Logging-while-coring method and apparatus

    DOEpatents

    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.

  8. Optimal message log reclamation for uncoordinated checkpointing

    NASA Technical Reports Server (NTRS)

    Wang, Yi-Min; Fuchs, W. K.

    1994-01-01

    Uncoordinated checkpointing for message-passing systems allows maximum process autonomy and general nondeterministic execution, but suffers from potential domino effect and the large space overhead for maintaining checkpoints and message logs. Traditionally, it has been assumed that only obsolete checkpoints and message logs before the global recovery line can be garbage-collected. Recently, an approach to identifying all garbage checkpoints based on recovery line transformation and decomposition has been developed. We show in this paper that the same approach can be applied to the problem of identifying all garbage message logs for systems requiring message logging to record in-transit messages. Communication trace-driven simulation for several parallel programs is used to evaluate the proposed algorithm.

  9. Sisyphus - An Event Log Analysis Toolset

    2004-09-01

    Event logs are a ubiquitous source of system feedback from computer systems, but have widely ranging format and can be extremely numerous, particularly from systems with many logging components. Inspection of these logs is fundamental to system debugging; increased capability to quickly extract meaningful information will impact MTTR (mean time to repair) and may impact MTBF (mean time between failure). Sisyphus is a machine-leanring analysis system whose goal is to enable content-novice analysts to efficieniiymore » understand evolving trends, identify anomalies, and investigate cause-effect hypotheses in large multiple-souce log sets. The toolkit is comprised a framework for utilizing third-party frequentitemset data mining tools Teiresias and SLCT. and software to cluster messages according to time statistics, and an interactive results viewer.« less

  10. RIAPROG: logit-log radioimmunoassay data processing

    SciTech Connect

    Faden, V.B.; Huston, J.C. Jr.; Munson, P.J.; Rodbard, D.

    1980-03-01

    This document provides the users guide and program listings for the 1980 version of RIAPROG. RIAPROG is a program for weighted least squares linear regression using the logit-log model for analysis of RIA results.

  11. Expansion of industrial logging in Central Africa.

    PubMed

    Laporte, Nadine T; Stabach, Jared A; Grosch, Robert; Lin, Tiffany S; Goetz, Scott J

    2007-06-01

    Industrial logging has become the most extensive land use in Central Africa, with more than 600,000 square kilometers (30%) of forest currently under concession. With use of a time series of satellite imagery for the period from 1976 to 2003, we measured 51,916 kilometers of new logging roads. The density of roads across the forested region was 0.03 kilometer per square kilometer, but areas of Gabon and Equatorial Guinea had values over 0.09 kilometer per square kilometer. A new frontier of logging expansion was identified within the Democratic Republic of Congo, which contains 63% of the remaining forest of the region. Tree felling and skid trails increased disturbance in selectively logged areas. PMID:17556578

  12. Applying time series analysis to performance logs

    NASA Astrophysics Data System (ADS)

    Kubacki, Marcin; Sosnowski, Janusz

    2015-09-01

    Contemporary computer systems provide mechanisms for monitoring various performance parameters (e.g. processor or memory usage, disc or network transfers), which are collected and stored in performance logs. An important issue is to derive characteristic features describing normal and abnormal behavior of the systems. For this purpose we use various schemes of analyzing time series. They have been adapted to the specificity of performance logs and verified using data collected from real systems. The presented approach is useful in evaluating system dependability.

  13. DOE/Simplec magnetic susceptibility logging system

    SciTech Connect

    Emilia, D.A.; Allen, J.W.; Chessmore, R.B.; Wilson, R.B.

    1981-03-01

    A magnetic susceptibility logging system has been developed which is relatively stable under normal field logging conditions and which produces logs that accurately represent in situ variations in magnetic susceptibility. However, both field and laboratory tests indicate the need for further improvement of temperature stabilization and bridge compensation; a new generation system designed by Simplec may fill that need. A cubic granite block with a magnetic susceptibility of 385 ..mu..CGS is designated as the primary calibration standard and is available for public use at the DOE facility in Grand Junction, Colorado. Models are also available for characterization of magnetic susceptibility systems. These include models to provide borehole size correction factors, thin layer interpretation parameters, reproducibility limits, longitudinal resolution, and radius of investigation. The DOE/Simplec system has a 99-percent radius of investigation, approximately equal to the coil length (15 inches), and a 99-percent thickness of investigation, approximately equal to two coil lengths. The true magnetic susceptibility and thickness of isolated layers less than two coil lengths in thickness can be obtained through use of parameters measured from their log responses. Field tests show that the system has a reproducibility of at least 5 ..mu..CGS and that logging at 25 ft/min is a good compromise between speed of operation and keeping the probe on the sidewall. Comparison of log and core magnetic susceptibility measurements confirms the fact that the logging system samples a rather large volume and that interpretive aids are necessary to unfold the true variation of magnetic susceptibility with depth. Finally, logs from known uranium-favorable environments show that magnetic susceptibility measurements can give an indication of the degree of geochemical alteration, which is one of the uranium-favorable haloes sought by exploration geologists.

  14. 32 CFR 700.845 - Maintenance of logs.

    Code of Federal Regulations, 2010 CFR

    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...

  15. 29 CFR 42.7 - Complaint/directed action logs.

    Code of Federal Regulations, 2010 CFR

    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...

  16. Web Logs in the English Classroom: More Than Just Chat.

    ERIC Educational Resources Information Center

    Richardson, Will

    2003-01-01

    Details the use and appeal of Web logs to enhance classroom discussion and allow for outside involvement in the classroom. Defines a Web log, addresses discussing literature in a Web log, and describes the author's first attempts at using Web-log technology. Presents considerations for using Web logs as part of classroom instruction. (SG)

  17. 29 CFR 42.7 - Complaint/directed action logs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 29 Labor 1 2013-07-01 2013-07-01 false 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...

  18. 29 CFR 42.7 - Complaint/directed action logs.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 29 Labor 1 2012-07-01 2012-07-01 false 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...

  19. 29 CFR 42.7 - Complaint/directed action logs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 29 Labor 1 2014-07-01 2013-07-01 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...

  20. 29 CFR 42.7 - Complaint/directed action logs.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false 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...

  1. Trip Information Log Tracking System

    SciTech Connect

    Jones, Jeffrey F.

    1992-06-23

    The system is focused on the Employee Business Travel Event. The system must be able to CRUD (Create, Retrieve, Update, Delete) instances of the Travel Event as well as the ability to CRUD frequent flyer milage associated with airline travel. Additionally the system must provide for a compliance reporting system to monitor reductions in travel costs and lost opportunity costs (i.e., not taking advantage of business class or 7 day advance tickets).

  2. CLARET user's manual: Mainframe Logs. Revision 1

    SciTech Connect

    Frobose, R.H.

    1984-11-12

    CLARET (Computer Logging and RETrieval) is a stand-alone PDP 11/23 system that can support 16 terminals. It provides a forms-oriented front end by which operators enter online activity logs for the Lawrence Livermore National Laboratory's OCTOPUS computer network. The logs are stored on the PDP 11/23 disks for later retrieval, and hardcopy reports are generated both automatically and upon request. Online viewing of the current logs is provided to management. As each day's logs are completed, the information is automatically sent to a CRAY and included in an online database system. The terminal used for the CLARET system is a dual-port Hewlett Packard 2626 terminal that can be used as either the CLARET logging station or as an independent OCTOPUS terminal. Because this is a stand-alone system, it does not depend on the availability of the OCTOPUS network to run and, in the event of a power failure, can be brought up independently.

  3. Evaluation of geophysical logs, Phase I, at Willow Grove Naval Air Station, Montgomery County, Pennsylvania

    USGS Publications Warehouse

    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.

  4. Application of fullbore formation microimager logging in the evaluation of anisotropic resistivity in a thin interbed reservoir

    NASA Astrophysics Data System (ADS)

    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.

  5. Principles of well diagnosis

    SciTech Connect

    McLeod, H.O.

    1994-12-31

    Well performance analysis provides an effective engineering resource for the analysis of well problems and the benefit possible from well workovers or well stimulation to improve well performance. Transient pressure testing and analysis has long been used to identify formation potential and to disclose wellbore restrictions; however, this methodology does not identify the source of restricted flow or a realistic potential of a well completion change. Well diagnosis not only involves pressure transient testing and analysis, but also well completion procedure analysis, well log analysis, special petrographic analysis, and flowing well system analysis (often called Nodal Analysis). Although reservoir flow and tubular flow are important in this systems analysis, well completion modeling is often the key to improvements through workover or stimulation. Several completion or wellbore models have been developed and presented in the last 20 years. Those models dealing with perforated wells and gravel packed wells will be reviewed and illustrated with case histories that demonstrate how well systems analysis leads to improved well performance. The geology of the formation is often critical in the analysis of formation damage and interpretation of well production problems, especially when flow is not sufficient to allow pressure transient testing. Well completion operation analysis is a developing art which incorporates an understanding of the latest research and a familiarity with field practice, and a strategy for this analysis will be provided.

  6. Cancer log-kill revisited.

    PubMed

    Norton, Larry

    2014-01-01

    At the root of science lie basic rules, if we can discover or deduce them. This is not an abstract project but practical; if we can understand the why then perhaps we can rationally intervene. One of the unifying unsolved problems in physics is the hypothetical "Theory of Everything." In a similar vein, we can ask whether our own field contains such hidden fundamental truths and, if so, how we can use them to develop better therapies and outcomes for our patients. Modern oncology has developed as drugs and translational science have matured over the 50 years since ASCO's founding, but almost from that beginning tumor modeling has been a key tool. Through this general approach Norton and Simon changed our understanding of cancer biology and response to therapy when they described the fit of Gompertzian curves to both clinical and animal observations of tumor growth. The practical relevance of these insights has only grown with the development of DNA sequencing promising a raft of new targets (and drugs). In that regard, Larry Norton's contribution to this year's Educational Book reminds us to always think creatively about the fundamental problems of tumor growth and metastases as well as therapeutic response. Demonstrating the creativity and thoughtfulness that have marked his remarkable career, he now incorporates a newer concept of self-seeding to further explain why Gompertzian growth occurs and, in the process, provides a novel potential therapeutic target. As you read his elegantly presented discussion, consider how this understanding, wisely applied to the modern era of targeted therapies, might speed the availability of better treatments. But even more instructive is his personal model-not only the Norton-Simon Hypothesis-of how to live and approach science, biology, patients and their families, as well as the broader community. He shows that with energy, enthusiasm, optimism, intellect, and hard work we can make the world better. Clifford A. Hudis, MD, FACP

  7. Personal protective equipment

    MedlinePlus

    ... protective equipment. Available at: www.cdc.gov/niosh/ppe . Accessed October 27, 2015. Holland MG, Cawthon D. Personal protective equipment and decontamination of adults and children. Emerg Med Clin N ...

  8. Medical Issues: Equipment

    MedlinePlus

    ... Pool Living With SMA Medical Issues Palliative Breathing Orthopedics Nutrition Equipment Daily Life At School At Home ... Diagnosed Living With SMA Medical Issues Palliative Breathing Orthopedics Nutrition Equipment Daily Life Grief & Loss Community & Local ...

  9. Rock Mechanical Properties from Logs Petrophysics : Concepts and Results

    NASA Astrophysics Data System (ADS)

    Gaillot, Philippe; Crawford, Brian; Alramahi, Bashar; Karner, Steve

    2010-05-01

    The objective of the "geomechanics from logs" (GML) research project is to develop model-driven predictive software for determining rock mechanical properties (specifically rock strength, compressibility and fracability) from other, more easily measured, rock properties (e.g. lithology, porosity, clay volume, velocity) routinely derived from nuclear, resistivity and acoustic logging tools. To this end, geomechanics from logs seeks to increase fundamental understanding of the primary geologic controls on rock mechanical properties and to translate this new insight into novel predictive tools. In detail, GML predictors rely on (i) the generation of relational rock mechanical properties databases incorporating QC'd core-based laboratory measurements (both in-house and high-precision published data); (ii) the use of established rock physics models (e.g. friable sand, contact cement models) to investigate theoretical relationships between geologic processes, reservoir environment, rock microstructure and elastic, bulk and transport petrophysical attributes/properties; (iii) the subdivision of database rocks into generic lithotypes (e.g. sand, shaly sand, sandy shale, shale) with common petrophysical attributes/properties; (iv) the use of multivariate statistics to generate lithotype-dependent empirical predictive relationships between mechanical properties and log-derived petrophysical attributes/properties; (v) the estimation of uncertainties associated with predictive function parameters; (vi) the application and validation of mechanical properties predictive tools to well-documented case studies (e.g. sand strength for perforation stability, rock compressibility for reservoir simulation) to test overall performance and quantify uncertainty in predictions. This paper presents the results of various rock strength, rock compressibility and rock fracability case studies conducted in wells of different stratigraphic age and depositional environment. Overall, GML (i

  10. First Riser Logging in Scientific Ocean Drilling: Operational Planning and results/reality

    NASA Astrophysics Data System (ADS)

    Sanada, Yoshinori; Kyaw Thu, Moe; Kido, Yukari; Kawamura, Yoshihisa; Hino, Ryota; Eguchi, Nabuhisa; Toczko, Sean; Takahashi, Kyoma; 319 Science Party, Iodp

    2010-05-01

    distribution. The 16 sets of the no planned 3-C geophone are clumped with 15m spacing at ~1300-1600mbsf in the cased C0009 hole by Chikyu. Eight OBS (Ocean Bottom Seismometer)s deployed at the seafloor. JAMSTEC R/V Kairei shot along 53km line (maximum offset from the hole is ~30km) and round 3.5km circle with 16-array tuned air-gun. Zero-offset VSP was conducted to measure velocity and create seismogram along the well as well. Using high resolution data obtained from the equipment, detailed structural interpretation, anisotropy analysis, and shear velocity analysis are being carried out. Riser drilling takes not only operational advantages such as deeper and safety hole, but also scientific advantage such as increasing measurement items which has never done in riserless drilling and improving data quality. It enlarge the options to approach new discovery and Science.

  11. Use of internet search logs to evaluate potential drug adverse events.

    PubMed

    Sarntivijai, S; Abernethy, D R

    2014-08-01

    Internet search logs provide an abundant source of data that can be explored for purposes such as identifying drug exposure-adverse event relationships. The methodology to rigorously conduct such evaluations is not well characterized, and the utility of such analyses is not well defined. In this issue, White and colleagues propose an approach using Internet search logs for this purpose and compare it to parallel analyses conducted using the US Food and Drug Administration's spontaneous reporting database.

  12. Exercise Equipment: Neutral Buoyancy

    NASA Technical Reports Server (NTRS)

    Shackelford, Linda; Valle, Paul

    2016-01-01

    Load Bearing Equipment for Neutral Buoyancy (LBE-NB) is an exercise frame that holds two exercising subjects in position as they apply counter forces to each other for lower extremity and spine loading resistance exercises. Resistance exercise prevents bone loss on ISS, but the ISS equipment is too massive for use in exploration craft. Integrating the human into the load directing, load generating, and motion control functions of the exercise equipment generates safe exercise loads with less equipment mass and volume.

  13. Thermal Properties of Bazhen fm. Sediments from Thermal Core Logging

    NASA Astrophysics Data System (ADS)

    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).

  14. Mobile Equipment Expands Inventory.

    ERIC Educational Resources Information Center

    McGough, Robert L.; And Others

    1978-01-01

    Describes the Mobile Equipment Modules (MEM) system in Duluth, Minnesota. MEM is a way to hold down costs and increase learning opportunities by consolidating purchases of expensive shop equipment within the school district, grouping the equipment in modules, and scheduling and moving it from school to school as needed. (MF)

  15. Predicting hospital visits from geo-tagged Internet search logs.

    PubMed

    Agarwal, Vibhu; Han, Lichy; Madan, Isaac; Saluja, Shaurya; Shidham, Aaditya; Shah, Nigam H

    2016-01-01

    The steady rise in healthcare costs has deprived over 45 million Americans of healthcare services (1, 2) and has encouraged healthcare providers to look for opportunities to improve their operational efficiency. Prior studies have shown that evidence of healthcare seeking intent in Internet searches correlates well with healthcare resource utilization. Given the ubiquitous nature of mobile Internet search, we hypothesized that analyzing geo-tagged mobile search logs could enable us to machine-learn predictors of future patient visits. Using a de-identified dataset of geo-tagged mobile Internet search logs, we mined text and location patterns that are predictors of healthcare resource utilization and built statistical models that predict the probability of a user's future visit to a medical facility. Our efforts will enable the development of innovative methods for modeling and optimizing the use of healthcare resources-a crucial prerequisite for securing healthcare access for everyone in the days to come. PMID:27570641

  16. Slimhole Drilling, Logging, and Completion Technology - An Update

    SciTech Connect

    FINGER,JOHN T.; JACOBSON,RONALD D.

    1999-10-07

    Using slim holes (diameter < 15 cm) for geothermal exploration and small-scale power production can produce significant cost savings compared to conventional rotary-drilling methods. In addition, data obtained from slim holes can be used to lower the risks and costs associated with the drilling and completion of large-diameter geothermal wells. As a prime contractor to the U.S. Department of Energy (DOE), Sandia National Laboratories has worked with industry since 1992 to develop and promote drilling, testing, and logging technology for slim holes. This paper describes the current status of work done both in-house and contracted to industry. It focuses on drilling technology, case histories of slimhole drilling projects, data collection and rig instrumentation, and high-temperature logging tools.

  17. Predicting hospital visits from geo-tagged Internet search logs.

    PubMed

    Agarwal, Vibhu; Han, Lichy; Madan, Isaac; Saluja, Shaurya; Shidham, Aaditya; Shah, Nigam H

    2016-01-01

    The steady rise in healthcare costs has deprived over 45 million Americans of healthcare services (1, 2) and has encouraged healthcare providers to look for opportunities to improve their operational efficiency. Prior studies have shown that evidence of healthcare seeking intent in Internet searches correlates well with healthcare resource utilization. Given the ubiquitous nature of mobile Internet search, we hypothesized that analyzing geo-tagged mobile search logs could enable us to machine-learn predictors of future patient visits. Using a de-identified dataset of geo-tagged mobile Internet search logs, we mined text and location patterns that are predictors of healthcare resource utilization and built statistical models that predict the probability of a user's future visit to a medical facility. Our efforts will enable the development of innovative methods for modeling and optimizing the use of healthcare resources-a crucial prerequisite for securing healthcare access for everyone in the days to come.

  18. Predicting hospital visits from geo-tagged Internet search logs

    PubMed Central

    Agarwal, Vibhu; Han, Lichy; Madan, Isaac; Saluja, Shaurya; Shidham, Aaditya; Shah, Nigam H.

    2016-01-01

    The steady rise in healthcare costs has deprived over 45 million Americans of healthcare services (1, 2) and has encouraged healthcare providers to look for opportunities to improve their operational efficiency. Prior studies have shown that evidence of healthcare seeking intent in Internet searches correlates well with healthcare resource utilization. Given the ubiquitous nature of mobile Internet search, we hypothesized that analyzing geo-tagged mobile search logs could enable us to machine-learn predictors of future patient visits. Using a de-identified dataset of geo-tagged mobile Internet search logs, we mined text and location patterns that are predictors of healthcare resource utilization and built statistical models that predict the probability of a user’s future visit to a medical facility. Our efforts will enable the development of innovative methods for modeling and optimizing the use of healthcare resources—a crucial prerequisite for securing healthcare access for everyone in the days to come. PMID:27570641

  19. Spreadsheet log analysis in subsurface geology

    USGS Publications Warehouse

    Doveton, J.H.

    2000-01-01

    Most of the direct knowledge of the geology of the subsurface is gained from the examination of core and drill-cuttings recovered from boreholes drilled by the petroleum and water industries. Wireline logs run in these same boreholes generally have been restricted to tasks of lithostratigraphic correlation and thee location of hydrocarbon pay zones. However, the range of petrophysical measurements has expanded markedly in recent years, so that log traces now can be transformed to estimates of rock composition. Increasingly, logs are available in a digital format that can be read easily by a desktop computer and processed by simple spreadsheet software methods. Taken together, these developments offer accessible tools for new insights into subsurface geology that complement the traditional, but limited, sources of core and cutting observations.

  20. Log-rolling block copolymers cylinders

    NASA Astrophysics Data System (ADS)

    Kim, So Youn; Kim, Ye Chan; Kim, Dong Hyup; Kwon, Na Kyung; Register, Richard A.

    Shear has been the most effective method to create long range order of micro- or nano- structures in soft materials. When shear is applied, soft particles or polymers tend to align along the shear direction to minimize the viscous dissipation, thus transverse (so-called ``log-rolling'') alignment is unfavored. In this study, for the first time we report the transverse alignment of cylinder-forming block copolymers. Poly(styrene-b-methyl methacrylate), PS-PMMA, can form a metastable hemicylinder structure when confined in a thin film, and this hemicylinder structure can align either along the shear direction, or transverse to the shear direction (``log-rolling''), depending on the shearing temperature. This unusual ``log-rolling'' behavior is explained by the different chain mobility of the two blocks in PS-PMMA; the rigidity of core cylinder is the critical parameter determining the direction of shear alignment.

  1. Use of geophysical logs to estimate water-quality trends in carbonate aquifers

    USGS Publications Warehouse

    MacCary, Lawrence Mead

    1980-01-01

    The water quality in carbonate aquifers can be determined by analysis of resistivity and porosity logs. When supporting data from water analyses are available, the value of the cementation exponent m can be determined more precisely. Data for this study were taken from logs of oil-test wells, Amstrat sample studies, drill-stem tests and water test wells in parts of Montana, North and South Dakota, and Wyoming. The preferred resistivity curves for apparent water resistivity (Rwa) analyses are the deeply focused laterolog and the induction log. The standard electric log can be used if the drilling mud is not saturated with salt. The preferred porosity logs are the sonic, sidewall neutron, compensated neutron, and the density logs. Older, uncalibrated neutron curves can be empirically calibrated in some instances, however, resulting porosities are frequently anomalous when compared to those determined from core or modern logs. When apparent water resistivity is determined for many wells, the data can be plotted and contoured to outline areas of recharge, direction of probable ground-water movement, and location and salinity of brine areas. (USGS)

  2. Logging while fishing: An alternate method to cut and thread fishing

    SciTech Connect

    Tollefsen, E.; Crary, S.; Flores, B.

    1996-12-31

    New technology has been introduced to allow completion of the wireline logging program after the tool string has become lodged in the wellbore. Charges associated with extracting a stuck tool are substantial. These charges result from the nonproductive time during the fishing trip, an associated wiper trip, and re-logging the well. The ability to continue the logging program while retrieving the logging string from the wellbore is needed. Logging While Fishing (LWF) is a hybrid of existing technologies combined with a new sub capable of severing a cable remotely. This new method is comprised of cut and thread fishing, drillpipe conveyed logging, and bridled tool techniques. Utilizing these techniques it is possible to complete wireline logging operations while removing a stuck tool from the wellbore. Completing logging operations using this hybrid method will save operating companies time and money. Other benefits, depending on the situation, include reduced fishing time and an increased level of safety. This application has been demonstrated on jobs in the Gulf of Mexico, North Sea, Venezuela, and Southeast Asia.

  3. Relationships between log N-log S and celestial distribution of gamma-ray bursts

    NASA Technical Reports Server (NTRS)

    Nishimura, J.; Yamagami, T.

    1985-01-01

    The apparent conflict between log N-log S curve and isotropic celestial distribution of the gamma ray bursts is discussed. A possible selection effect due to the time profile of each burst is examined. It is shown that the contradiction is due to this selection effect of the gamma ray bursts.

  4. LogSafe and Smart: Minnesota OSHA's LogSafe Program Takes Root.

    ERIC Educational Resources Information Center

    Honerman, James

    1999-01-01

    Logging is now the most dangerous U.S. occupation. The Occupational Safety and Health Administration (OSHA) developed specialized safety training for the logging industry but has been challenged to reach small operators. An OSHA-approved state program in Minnesota provides annual safety seminars to about two-thirds of the state's full-time…

  5. Arabidopsis lonely guy (LOG) multiple mutants reveal a central role of the LOG-dependent pathway in cytokinin activation.

    PubMed

    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.

  6. Field Demonstration of Slim-hole Borehole Nuclear Magnetic Resonance (NMR) Logging Tool for Groundwater Investigations

    NASA Astrophysics Data System (ADS)

    Walsh, D.; Turner, P.; Frid, I.; Shelby, R.; Grunewald, E. D.; Magnuson, E.; Butler, J. J.; Johnson, C. D.; Cannia, J. C.; Woodward, D. A.; Williams, K. H.; Lane, J. W.

    2010-12-01

    Nuclear magnetic resonance (NMR) methods provide estimates of free and bound water content and hydraulic conductivity, which are critically important for groundwater investigations. Borehole NMR tools have been available and widely used in the oil industry for decades, but only recently have been designed for small diameter boreholes typical of groundwater investigations. Field tests of an 89-mm-diameter borehole NMR logging tool are presented. This borehole NMR logging tool was developed for economical NMR logging of 100- to 200-mm-diameter boreholes, and specifically for characterizing hydraulic properties in the top 200 m of the subsurface. The tool has a vertical resolution of 0.5 m, a minimum echo spacing of 2.0 ms, and a radial depth of investigation of 178 to 203 mm, which typically is beyond the annulus of observation wells. It takes about 15 minutes to collect a data sample for each 0.5-m interval. The borehole NMR logging tool was field tested during spring 2010, in PVC-cased wells at sites in East Haddam and Storrs, Connecticut; Cape Cod, Massachusetts; Lexington, Nebraska; Lawrence, Kansas; and Rifle, Colorado. NMR logging yielded estimates of bound water, free water, and total-water content, as well as continuous distributions of water content versus transverse relaxation time (T2) at all depth levels. The derived water-content data were compared to the available ground-truth hydrogeologic data from each well, including drilling logs, neutron and other geophysical logs, and direct measurements of hydraulic conductivity. The results indicate that the borehole NMR logging tool provides information on porosity, pore-size distribution, and estimated hydraulic conductivity that cannot be duplicated by any other single geophysical logging tool.

  7. MAIL LOG, program summary and specifications

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    The summary and specifications to obtain the software package, MAIL LOG, developed for the Scout Project Automatic Data System, SPADS are provided. The MAIL LOG program has four modes of operation: (1) input - putting new records into the data base; (2) revise - changing or modifying existing records in the data base; (3) search - finding special records existing in the data base; and (4) archive - store or put away existing records in the data base. The output includes special printouts of records in the data base and results from the input and search modes.

  8. Permeability extraction: A sonic log inversion

    SciTech Connect

    Akbar, N.; Kim, J.J.

    1994-12-31

    In this paper the authors provide the missing important link between permeability and acoustic velocities by generating a permeability-dependent synthetic sonic log in a carbonate reservoir. The computations are based on Akbar`s theory that relates wave velocity to frequency, rock properties (e.g., lithology, permeability, and porosity), and fluid saturation and properties (viscosity, density, and compressibility). An inverted analytical expression of the theory is used to extract permeability from sonic velocity. The synthetic sonic and the computed permeability are compared with the observed sonic log and with plug permeability, respectively. The results demonstrate, as predicted by theory, that permeability can be related directly to acoustic velocities.

  9. Compacting a Kentucky coal for quality logs

    SciTech Connect

    Lin, Y.; Li, Z.; Mao, S.

    1999-07-01

    A Kentucky coal was found more difficult to be compacted into large size strong logs. Study showed that compaction parameters affecting the strength of compacted coal logs could be categorized into three groups. The first group is coal inherent properties such as elasticity and coefficient of friction, the second group is machine properties such as mold geometry, and the third group is the coal mixture preparation parameters such as particle size distribution. Theoretical analysis showed that an appropriate backpressure can reduce surface cracks occurring during ejection. This has been confirmed by the experiments conducted.

  10. Strategy Guideline. HVAC Equipment Sizing

    SciTech Connect

    Burdick, Arlan

    2012-02-01

    This guide describes the equipment selection of a split system air conditioner and furnace for an example house in Chicago, IL as well as a heat pump system for an example house in Orlando, FL. The required heating and cooling load information for the two example houses was developed in the Department of Energy Building America Strategy Guideline: Accurate Heating and Cooling Load Calculations.

  11. Renewal of radiological equipment.

    PubMed

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  12. Renewal of radiological equipment.

    PubMed

    2014-10-01

    In this century, medical imaging is at the heart of medical practice. Besides providing fast and accurate diagnosis, advances in radiology equipment offer new and previously non-existing options for treatment guidance with quite low morbidity, resulting in the improvement of health outcomes and quality of life for the patients. Although rapid technological development created new medical imaging modalities and methods, the same progress speed resulted in accelerated technical and functional obsolescence of the same medical imaging equipment, consequently creating a need for renewal. Older equipment has a high risk of failures and breakdowns, which might cause delays in diagnosis and treatment of the patient, and safety problems both for the patient and the medical staff. The European Society of Radiology is promoting the use of up-to-date equipment, especially in the context of the EuroSafe Imaging Campaign, as the use of up-to-date equipment will improve quality and safety in medical imaging. Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or renewal. This plan should look forward a minimum of 5 years, with annual updates. Teaching points • Radiological equipment has a definite life cycle span, resulting in unavoidable breakdown and decrease or loss of image quality which renders equipment useless after a certain time period.• Equipment older than 10 years is no longer state-of-the art equipment and replacement is essential. Operating costs of older equipment will be high when compared with new equipment, and sometimes maintenance will be impossible if no spare parts are available.• Older equipment has a high risk of failure and breakdown, causing delays in diagnosis and treatment of the patient and safety problems both for the patient and the medical staff.• Every healthcare institution or authority should have a plan for medical imaging equipment upgrade or replacement. This plan should look forward a

  13. MAIL LOG, program theory, volume 2

    NASA Technical Reports Server (NTRS)

    Harris, D. K.

    1979-01-01

    Information relevant to the MAIL LOG program theory is documented. The L-files for mail correspondence, design information release/report, and the drawing/engineering order are given. In addition, sources for miscellaneous external routines and special support routines are documented along with a glossary of terms.

  14. Discovering the Local Landscape: Pioneer Log Buildings.

    ERIC Educational Resources Information Center

    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…

  15. [Human development and log-periodic law].

    PubMed

    Cash, Roland; Chaline, Jean; Nottale, Laurent; Grou, Pierre

    2002-05-01

    We suggest applying the log-periodic law formerly used to describe various crisis phenomena, in biology (evolutionary leaps), inorganic systems (earthquakes), societies and economy (economic crisis, market crashes) to the various steps of human ontogeny. We find a statistically significant agreement between this model and the data.

  16. Modelling tropical forests response to logging

    NASA Astrophysics Data System (ADS)

    Cazzolla Gatti, Roberto; Di Paola, Arianna; Valentini, Riccardo; Paparella, Francesco

    2013-04-01

    Tropical rainforests are among the most threatened ecosystems by large-scale fragmentation due to human activity such as heavy logging and agricultural clearance. Although, they provide crucial ecosystem goods and services, such as sequestering carbon from the atmosphere, protecting watersheds and conserving biodiversity. In several countries forest resource extraction has experienced a shift from clearcutting to selective logging to maintain a significant forest cover and understock of living biomass. However the knowledge on the short and long-term effects of removing selected species in tropical rainforest are scarce and need to be further investigated. One of the main effects of selective logging on forest dynamics seems to be the local disturbance which involve the invasion of open space by weed, vines and climbers at the expense of the late-successional state cenosis. We present a simple deterministic model that describes the dynamics of tropical rainforest subject to selective logging to understand how and why weeds displace native species. We argue that the selective removal of tallest tropical trees carries out gaps of light that allow weeds, vines and climbers to prevail on native species, inhibiting the possibility of recovery of the original vegetation. Our results show that different regime shifts may occur depending on the type of forest management adopted. This hypothesis is supported by a dataset of trees height and weed/vines cover that we collected from 9 plots located in Central and West Africa both in untouched and managed areas.

  17. There's Life in Those Dead Logs!

    ERIC Educational Resources Information Center

    Biggs, Devin; Miller, Todd; Hall, Dee

    2006-01-01

    Although it is unspectacular in appearance, dead wood is one of the most ecologically important resources in forests. Fallen logs, dead standing trees, stumps, and even cavities in live trees fulfill a wide range of roles. Prominent among these is that they provide habitat for many organisms, especially insects. Fourth-grade students at Fox…

  18. 47 CFR 80.409 - Station logs.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... statement of any corrective action taken. (5) Entries must be made giving details of all work performed... written log signed by the operator who supervised or performed the work and, unless the operator is... made comparing the radio station clock with standard time, including errors observed and...

  19. 47 CFR 80.409 - Station logs.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... statement of any corrective action taken. (5) Entries must be made giving details of all work performed... written log signed by the operator who supervised or performed the work and, unless the operator is... made comparing the radio station clock with standard time, including errors observed and...

  20. 47 CFR 73.1840 - Retention of logs.

    Code of Federal Regulations, 2010 CFR

    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...