Geophysical borehole logging, dummy-sonding and optical imaging of the borehole OL-KR24 at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2006-03-01

Suomen Malmi Oy conducted geophysical borehole logging, dummy-sonding and optical imaging surveys of the borehole OL-KR24 at the Olkiluoto site in Eurajoki during 1.10.2005 - 4.10.2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The methods applied are caliper survey and optical imaging. The assignment included the field work of surveys, interpretation and processing of the data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Borehole geophysics in nuclear power plant siting

International Nuclear Information System (INIS)

Crosby, J.W.; Scott, J.D.

1979-01-01

Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative perameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape

Borehole geophysics in nuclear power plant siting

International Nuclear Information System (INIS)

Crosby, J.W.; Scott, J.D.

1979-01-01

Miniaturized borehole geophysical equipment designed for use in ground-water investigations can be adapted to investigations of nuclear power plant sites. This equipment has proved to be of value in preliminary and comprehensive studies of interior basins where thick sequences of Quaternary clastic sediment, occasionally with associated volcanic rocks, pose problems of stratigraphic correlation. The unconsolidated nature of the deposits generally requires that exploratory holes be cased, which ordinarily restricts the borehole geophysical studies to the radiation functions--natural gamma, gamma-gamma, neutron-gamma, and neutron-epithermal neutron logs. Although a single log response may be dominant in a given area, correlations derive from consideration of all log responses as a composite group. Because major correlations usually are based upon subtle differences in the physical properties of the penetrated sediment, high-resolution logging procedures are employed with some sacrifice of the quantitative parameters important to petroleum technology. All geophysical field data are recorded as hard copy and as digital information on punched paper tape. Digital data are subsequently computer processed and plotted to scales that enhance the stratigraphic data being correlated. Retention of the data in analog format permits rapid review, whereas computer plotting allows playback and detailed examination of log sections and sequences that may be attenuated on hard copy because of the logarithmic nature of the response to the physical property being examined

Additional borehole geophysical logging at Waste Area Grouping 1 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1994-07-01

This technical memorandum describes the borehole geophysical logging performed at selected coreholes at Waste Area Grouping 1 between March and November 1991 in support of the remedial investigation. The primary objectives of the borehole geophysical logging program were to (1) identify fractured bedrock zones and identify those fractured bedrock zones participating in active groundwater flow, (2) correlate the fractured intervals with the regional stratigraphy described, and (3) further characterize local bedrock geology and hydrogeology and gain insight about the bedrock aquifer flow system. A secondary objective was to provide stratigraphic correlations with existing logs for coreholes CH001 through CH005. Fractured bedrock zones and active or open fractures were identified in all coreholes logged. The fracture identification and analysis process was intended to distinguish between open or active fractures participating in active groundwater flow and closed or inactive fractures that are partially or completely filled (such as with calcite mineralization) and do not support groundwater circulation. Most of the fractures identified are bedding plane. Fracture occurrence varies with the different units of the Chickamauga Group; the greatest density of fractures and active fractures occurs in the upper 150 ft of stratum cored. Fractures actively contributing to groundwater flow were also identified, and direction of fluid movement within fractures was identified for those coreholes with flowmeter data

Geophysical borehole logging in selected areas in the Greater Accra plains and the Densu river basin

International Nuclear Information System (INIS)

Amartey, E. A.

2009-06-01

Geophysical borehole logging was complemented by Vertical Electrical Sounding (VES) method to study fractured bedrock aquifer systems on the compounds of Ghana Atomic Energy Commission (GAEC), Water Research Institute (WRI) in the Accra Plains and the Hydrometric Station of the Department of Geology, University of Ghana at Buokrom in the Densu River Basin. Single-point resistance, resistivity and natural gamma logging in a total of nine boreholes were conducted to identify and characterize the various aquifers in the study areas. Results obtained from the single-point resistance and resistivity logs showed clearly the characteristics of water-bearing fracture zones in the various rock formations. The gamma logs obtained for each area were correlated to form hydrostratigraphic units to establish potential zones of high water-bearing fractures. VES modeled curves shows hydrogeological units of the geological formation which compares well with features obtained on the logs. The investigation identified fractured zone thicknesses of <1 m to 2 m at GAEC area, <1 m to 9 m at WRI area and <1 m to 10 m thicknesses at the Buokrom area. The fractured bedrock aquifers identified have been characterized based on their thicknesses as follows. Five minor (thickness < 5 m), two medium (thickness 5 m to 14 m) and three major (thickness ⩾15 m) fractures were identified at the GAEC area. At the WRI area three minor and five medium fractures were identified. Also four minor and five medium fractures were identified for the Buokrom area boreholes. (au)

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

Science.gov (United States)

Twining, Brian V.; Bartholomay, Roy C.

2011-01-01

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

Synthesis of borehole geophysical data at the Underground Research Laboratory, Manitoba, Canada

International Nuclear Information System (INIS)

Keys, W.S.

1984-07-01

A suite of borehole-geophysical logs, supported by core data, was used to describe the rock matrix and fractures in a granitic pluton near Lac du Bonnet, Manitoba, Canada. The site is being developed by Atomic Energy of Canada Limited, as an underground research laboratory to conduct geotechnical research and to validate predictive models as part of Canada's nuclear-fuel, waste-management program. However, the site is not planned to be used for waste disposal. Geophysical well logs were used to distinguish and correlate rock types and fractures between drill holes. Two significant fracture zones that are two of the major zones of ground-water movement at the site were identified by acoustic-televiewer logs. A new heat-pulse flowmeter provided repeatable measurements of very low-velocity, vertical flow in drill holes which enabled the identification of specific fractures that were transmitting water. Borehole gamma spectra showed that some fractures are enriched in uranium, and others may be depleted. This study demonstrates some of the advantages of synthesizing available borehole-geophysical logs at a site in fractured plutonic rocks and indicates how this information can contribute to an understanding of the geophysical conditions at the site

Specific features of well logging of boreholes drilled on electrical nonconducting solutions

International Nuclear Information System (INIS)

Ruchkin, A.F.; Fomenko, V.G.

1978-01-01

Methods for identification of permeable strata and determination of their porosity and oil-gas saturation using standard combination of geophysical investigations in the boreholes drilled with nonaqueous and inert drilling fluids are considered. Geophysical combination consists of the methods indications of which are independent on electrical conductivity of drilling fluids. They are all modifications of radioactivity logging (gamma logging, neutron logging, neutron-gamma logging, gamma-gamma logging, pulsed neutron logging, nuclear-magnetic logging), acoustic logging and thermal logging

Use of borehole-geophysical logs and hydrologic tests to characterize crystalline rock for nuclear-waste storage, Whiteshell Nuclear Research Establishment, Manitoba, and Chalk River Nuclear Laboratory, Ontario, Canada

International Nuclear Information System (INIS)

Davison, C.C.

1982-12-01

A number of borehole methods were used in the investigation of crystalline rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratory in Canada. The selection of a crystalline-rock mass for the storage of nuclear waste likely will require the drilling and testing of a number of deep investigative boreholes in the rock mass. Although coring of at least one hole in each new area is essential, methods for making in-situ geophysical and hydrologic measurements can substitute for widespread coring and result in significant savings in time and money. Borehole-geophysical logging techniques permit the lateral extrapolation of data from a core hole. Log response is related to rock type, alteration, and the location and character of fractures. The geophysical logs that particularly are useful for these purposes are the acoustic televiewer and acoustic waveform, neutron and gamma, resistivity, temperature, and caliper. The acoustic-televiewer log of the borehole wall can provide high resolution data on the orientation and apparent width of fractures. In situ hydraulic tests of single fractures or fracture zones isolated by packers provide quantitative information on permeability, extent, and interconnection. The computer analysis of digitized acoustic waveforms has identified a part of the waveform that has amplitude variations related to permeabilities measured in the boreholes by packer tests. 38 refs., 37 figs., 4 tabs

Borehole logging

International Nuclear Information System (INIS)

Olsen, H.

1995-01-01

Numerous ground water investigations have been accomplished by means of borehole logging. Borehole logging can be applied to establish new water recovery wells, to control the existing water producing wells and source areas and to estimate ground water quality. (EG)

Borehole geophysical investigations of Lavia deep testhole, Finland

International Nuclear Information System (INIS)

Saksa, Pauli

1985-02-01

According to the Goverment's decision in principle in 1983 Industrial Power Company Ltd (TVO) is making preparations for all the steps of final disposal of the spent fuel produced by its power plants. Before the actual site investigation phase, TVO drilled a deep borehole in Lavia, Western Finland. The borehole is used during 1984-85 for testing investigation techniques and methods used for bedrock characterization. Borehole geophysical loggings performed in Lavia consisted of galvanic electrical, transient electromagnetic, radiometric, temperature, seismic and magnetic msurements. This composite survey provided both lithological and structural information of rock mass. The neutron-neutron, density, natural gamma radiation and susceptibility methods characterized rock type. Fracturing and its type could be interpreted most effectively with resistivity, acoustic P-wave velocity and density logs. Temperature and tube-wave measurements revealed several fractured zones related to possible water flow in rock. Lavia investigations indicated that a high quality of instrumentation and careful calibration are necessary for site investigations. The large amount of log data also requires efficient data collection and processing systems both in the field and laboratory. (author)

Determination of In-situ Rock Thermal Properties from Geophysical Log Data of SK-2 East Borehole, Continental Scientific Drilling Project of Songliao Basin, NE China

Science.gov (United States)

Zou, C.; Zhao, J.; Zhang, X.; Peng, C.; Zhang, S.

2017-12-01

Continental Scientific Drilling Project of Songliao Basin is a drilling project under the framework of ICDP. It aims at detecting Cretaceous environmental/climate changes and exploring potential resources near or beneath the base of the basin. The main hole, SK-2 East Borehole, has been drilled to penetrate through the Cretaceous formation. A variety of geophysical log data were collected from the borehole, which provide a great opportunity to analyze thermal properties of in-situ rock surrounding the borehole.The geothermal gradients were derived directly from temperature logs recorded 41 days after shut-in. The matrix and bulk thermal conductivity of rock were calculated with the geometric-mean model, in which mineral/rock contents and porosity were required as inputs (Fuchs et. al., 2014). Accurate mineral contents were available from the elemental capture spectroscopy logs and porosity data were derived from conventional logs (density, neutron and sonic). The heat production data were calculated by means of the concentrations of uranium, thorium and potassium determined from natural gamma-ray spectroscopy logs. Then, the heat flow was determined by using the values of geothermal gradients and thermal conductivity.The thermal parameters of in-situ rock over the depth interval of 0 4500m in the borehole were derived from geophysical logs. Statistically, the numerical ranges of thermal parameters are in good agreement with the measured values from both laboratory and field in this area. The results show that high geothermal gradient and heat flow exist over the whole Cretaceous formation, with anomalously high values in the Qingshankou formation (1372.0 1671.7m) and the Quantou formation (1671.7 2533.5m). It is meaningful for characterization of geothermal regime and exploration of geothermal resources in the basin. Acknowledgment: This work was supported by the "China Continental Scientific Drilling Program of Cretaceous Songliao Basin (CCSD-SK)" of China

The Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin, NE China: Organic-rich source rock evaluation with geophysical logs from Borehole SK-2

Science.gov (United States)

Zhang, X.; Zou, C.

2017-12-01

The Cretaceous strata have been recognized as an important target of oil or gas exploration in the Songliao Basin, northeast China. The second borehole (SK-2) of the Chinese Cretaceous Continental Scientific Drilling Project in the Songliao Basin (CCSD-SK) is the first one to drill through the Cretaceous continental strata in the frame of ICDP. It was designed not only to solve multiple scientific problems (including the Cretaceous paleoenvironment and paleoclimate, as well as deep resources exploration of the Songliao Basin), but also to expect to achieve new breakthroughs in oil and gas exploration. Based on the project, various geophysical log data (including gamma, sonic, resistivity, density etc.) and core samples have been collected from Borehole SK-2. We do research on organic-rich source rocks estimation using various geophysical log data. Firstly, we comprehensively analyzed organic-rich source rocks' geophysical log response characteristics. Then, source rock's identification methods were constructed to identify organic-rich source rocks with geophysical logs. The main identification methods include cross-plot, multiple overlap and Decision Tree method. Finally, the technique and the CARBOLOG method were applied to evaluate total organic carbon (TOC) content from geophysical logs which provide continuous vertical profile estimations (Passey, 1990; Carpentier et al., 1991). The results show that source rocks are widely distributed in Borehole SK-2, over a large depth strata (985 5700m), including Nenjiang, Qingshankou, Denglouku, Yingcheng, Shahezi Formations. The organic-rich source rocks with higher TOC content occur in the Qingshankou (1647 1650m), Denglouku (2534 2887m) and Shahezi (3367 5697m) Formations. The highest TOC content in these formations can reach 10.31%, 6.58%, 12.79% respectively. The bed thickness of organic-rich source rocks in the these formations are totally up to 7.88m, 74.34m, 276.60m respectively. These organic-rich rocks in the

Development of nuclear physics and its connections to borehole geophysics

International Nuclear Information System (INIS)

Loetzsch, W.

1990-01-01

Starting from the discovery of radioactivity, the development of nuclear physics and its close connections to geoscience, especially to borehole geophysics, are outlined. The discovery of a nuclear physical phenomenon is always followed by an examination for its applications in nuclear geophysics, which since about 1960 has developed into a special discipline of applied geophysics. As an example for this development in the GDR the application of neutron capture γ-ray spectroscopy for iron ore exploration is described. A table listing important present-day nuclear well logging techniques with detectable elements and their detection limits is presented. Examples of measurements with some of these logging techniques reveal their particularities and show their element-specific character and the nuclear physical mechanisms involved. Finally the state of art of nuclear well logging and prospects in this field are outlined. (author)

Computer-based system for processing geophysical data obtained from boreholes

International Nuclear Information System (INIS)

Richter, J.M.

1982-01-01

A diverse set of computer programs has been developed at the Lawrence Livermore National Laboratory (LLNL) to process geophysical data obtained from boreholes. These programs support such services as digitizing analog records, reading and processing raw data, cataloging and storing processed data, retrieving selected data for analysis, and generating data plots on several different devices. A variety of geophysical data types are accommodated, including both wireline logs and laboratory analyses of downhole samples. Many processing tasks are handled by means of a single, flexible, general-purpose data-manipulation program. Separate programs are available for processing data from density, gravity, velocity, and epithermal neutron logs

Geophysical borehole logging of the boreholes KR30, KR31, KR31b, KR32, KR33, KR33b and KR24 Upper Part, at Olkiluoto 2005

International Nuclear Information System (INIS)

Majapuro, J.

2005-12-01

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR30, KR31, KR31B, KR32, KR33, KR33B and KR24 upper part at the Olkiluoto site in Eurajoki during December 2004, January, February and September 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

Geophysical borehole logging of the boreholes KR30, KR31, KR31b, KR32, KR33, KR33b and KR24 Upper Part, at Olkiluoto 2005

Energy Technology Data Exchange (ETDEWEB)

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

2005-12-15

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes KR30, KR31, KR31B, KR32, KR33, KR33B and KR24 upper part at the Olkiluoto site in Eurajoki during December 2004, January, February and September 2005. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes the field operation, equipment as well as processing procedures and shows the obtained results and their quality in the appendices. The raw and processed data are delivered digitally in WellCAD and Excel format. (orig.)

The ICDP Snake River Geothermal Drilling Project: preliminary overview of borehole geophysics

Science.gov (United States)

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

2012-01-01

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

Geophysical data from boreholes DM1, DM2, DM3, and DM3a, New Hydraulic Fracturing Facility, Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

Haase, C.S.

1987-03-01

A comprehensive suite of geophysical logs was obtained from four deep monitoring boreholes at the New Hydrofracture Facility. The logging was an attempt to obtain stratigraphic, structural, and hydrologic information on the subsurface environment surrounding the hydrofracture facility. Logs obtained include caliper, gamma, neutron, density, single-point resistance, long- and short-normal resistivity, spontaneous potential, temperature, acoustic velocity, variable density, and borehole televiewer. Analysis and interpretation of the geophysical logs allowed the stratigraphic section at the facility to be determined and, by comparison with calibrated geophysical logs from borehole ORNL-Joy No. 2, allowed detailed inferences to be drawn about rock types and properties at the hydrofracture facility. Porosity values measured from the logs for Conasauga Group strata, as well as permeability values inferred from the logs, are low. Several intervals of apparently greater permeability, associated primarily with limestone-rich portions of the Maryville Limestone and sandstone-rich portions of the Rome Formation, were noted. Numerous fractures were identified by using several logs in combination. No one geophysical log was reliable for fracture identification although the acoustic-televiewer log appeared to have the greatest success. In addition to their characterization of subsurface conditions in the vicinity of the hydrofracture facility, the geophysical logs provided data on the extent of hydraulic fractures. Anomalies on single-point resistance logs that corresponded to prominent fractures identified on televiewer logs indicate intervals affected by hydraulic fractures associated with waste injection at the New Hydrofracture Facility. 14 refs

Application of borehole geophysics to fracture identification and characterization in low porosity limestones and dolostones

International Nuclear Information System (INIS)

Haase, C.S.; King, H.L.

1986-01-01

Geophysical logging was conducted in exploratory core holes drilled for geohydrological investigations at three sites used for waste disposal on the US Department of Energy's Oak Ridge Reservation. Geophysical log response was calibrated to borehole geology using the drill core. Subsequently, the logs were used to identify fractures and fractured zones and to characterize the hydrologic activity of such zones. Results of the study were used to identify zones of ground water movement and to select targets for subsequent piezometer and monitoring well installation. Neutron porosity, long- and short-normal resistivity, and density logs exhibit anomalies only adjacent to pervasively fractured zones and rarely exhibit anomalies adjacent to individual fractures, suggesting that such logs have insufficient resolution to detect individual fractures. Spontaneous potential, single point resistance, acoustic velocity, and acoustic variable density logs, however, typically exhibit anomalies adjacent to both individual fractures and fracture zones. Correlation is excellent between fracture density logs prepared from the examination of drill core and fractures identified by the analysis of a suite of geophysical logs that have differing spatial resolution characteristics. Results of the study demonstrate the importance of (1) calibrating geophysical log response to drill core from a site, and (2) running a comprehensive suite of geophysical logs that can evaluate both large- and small-scale rock features. Once geophysical log responses to site-specific geological features have been established, logs provide a means of identifying fracture zones and discriminating between hydrologically active and inactive fracture zones. 9 figs

Borehole logging in uranium exploration

International Nuclear Information System (INIS)

Kulkarni, N.H.

1992-01-01

The ultimate objective of exploration by drilling as far as Atomic Minerals Division is concerned is to locate the ore zone in the subsurface, draw samples and analyze them for their metal content. The presence of the ore zone is also indicated by gamma-ray logging of the borehole. A gamma-ray detector is lowered in the borehole and precise depth and grade of the ore zone is established. This helps the geologist in correlating the ore horizon with the surface outcrop or the ore zone intercepted in adjoining boreholes and in deciding about further drilling and location of boreholes. Most commonly, total gamma measurements are made although some units capable of measuring the gamma-ray spectrum are also in use. It is possible to know if the mineralization is due to uranium without waiting for the laboratory results. The present write up gives a brief account of the principles, equipment and methods of borehole gamma-ray logging including density and self-potential logging. (author). 8 refs., 5 figs

Preliminary report on geophysical and mechanical borehole measurements at Stripa

International Nuclear Information System (INIS)

Nelson, P.; Paulsson, B.; Rachiele, R.; Andersson, L.; Schrauf, T.; Hustrulid, W.; Duran, O.; Magnusson, K.A.

1979-05-01

A suite of seven logs--neutron, gamma--gamma, resistivity, gamma ray, sonic, caliper, and temperature--operated in a borehole of 380-m depth located eleven zones where the rock permeability is expected to be enhanced due to the presence of open fractures. The sonic waveform record proved especially useful in this regard. Borehole measurements were also acquired in a large number of boreholes from 5- to 14-m length located in experimental drifts some 340-m underground. Here several physical properties, including the porosity, density, sonic velocity, and borehole rugosity, are generally quite uniform, with the exception of a few local chloritic zones and a few minor fractures. However, in situ determinations of the mechanical modulus with the CSM cell indicate substantial variability, with some apparent fracture control. Uranium and thorium concentrations are quite high in the Stripa granite, with local fluctuations associated with mineralogical changes as revealed by the gamma-ray log. A differential resistance probe appears promising as a sensitive detector of fine fracturing. A cross-hole ultrasonic system indicates variations of a few percent in compressional- and shear-wave velocities, reflecting the presence of fractures and changes in fracture characteristics as the rock is heated in a simulated storage test. The geophysical and mechanical data are being compared with the results from core and television logging, with hydrological test data on static pressure and injection permeability, and with displacements induced by thermal loading

Integrating surface and borehole geophysics in ground water studies - an example using electromagnetic soundings in south Florida

Science.gov (United States)

Paillet, Frederick; Hite, Laura; Carlson, Matthew

1999-01-01

Time domain surface electromagnetic soundings, borehole induction logs, and other borehole logging techniques are used to construct a realistic model for the shallow subsurface hydraulic properties of unconsolidated sediments in south Florida. Induction logs are used to calibrate surface induction soundings in units of pore water salinity by correlating water sample specific electrical conductivity with the electrical conductivity of the formation over the sampled interval for a two‐layered aquifer model. Geophysical logs are also used to show that a constant conductivity layer model is appropriate for the south Florida study. Several physically independent log measurements are used to quantify the dependence of formation electrical conductivity on such parameters as salinity, permeability, and clay mineral fraction. The combined interpretation of electromagnetic soundings and induction logs was verified by logging three validation boreholes, confirming quantitative estimates of formation conductivity and thickness in the upper model layer, and qualitative estimates of conductivity in the lower model layer.

Face logging in Copenhagen Limestone, Denmark

DEFF Research Database (Denmark)

Jakobsen, Lisa; Foged, Niels Nielsen; Erichsen, Lars

2015-01-01

tunnel in Copenhagen more than 2.5 km face logs were made in 467 locations at underground stations, shafts, caverns and along bored tunnels. Over 160 geotechnical boreholes, many with geophysical logging were executed prior to construction works. The bedrock consists of Paleogene "Copenhagen limestone......The requirement for excavation support can be assessed from face logging. Face logs can also improve our knowledge of lithological and structural conditions within bedrock and supplement information from boreholes and geophysical logs. During the construction of 8 km metro tunnel and 4 km heating....... The induration degrees recorded in face logs and boreholes are compared and correlated. Distinct geophysical log markers are used to divide the limestone into three units. These marker horizons are correlated between face logs and geotechnical boreholes. A 3D model of the strength variations recorded within...

Geophysical and geological borehole investigations for the characterization of a site for radioactive waste disposal

International Nuclear Information System (INIS)

Olsson, O.; Ahlbom, K.

1984-02-01

In the Swedish program for site investigations detailed geological and geophysical investigations are performed at areas of 4-6 km 2 at the surface. Normally around 10 deep core bore holes are drilled. The length of the holes is normally from 600 to 1000 m. The holes are drilled to verify the location of fracture zones and to investigate the physical and hydraulic properties of the fracture zones at large depths. Investigations have been performed in a number of sites with mainly granitic and gneissic rocks. The core from these boreholes is logged with the aid of a microcomputer system. The cores are mapped with respect to rock type, structure, fractures and fracture minerals. Indications of water flow, shearing and core-discing are also studied. The boreholes are logged with a suite of geophysical logs. Several different electrical logs are used and have been found to be good indicators of fracture zones. Normally the electrical logs in combination with the fracture frequency are used to define the limits of fracture zones crossing the borehole. The temperature log and the salinity log have proved to be good indicators of permeable zones. The data from each hole is correlated with data obtained from the other holes and the surface investigations to build a fracture zone model which is used for the hydraulic modelling of the site. In order to verify the extension of the fracture zones at a distance from the borehole cross-hole techniques have been applied. At the Swedish test site Finnsjoe and in the Stripa mine the suitability of the mise a la masse technique for mapping of fracture zones was tested. At the Finnsjoe site it was possible to map a fairly complex fracture system over distances up to 150 m. In the Stripa mine the object was to follow the extent of a major fracture zone for distances up to 600 m. It was possible to obtain an indication of the orientation of the fracture zone

Identification of potential water-bearing zones by the use of borehole geophysics in the vicinity of Keystone Sanitation Superfund Site, Adams County, Pennsylvania and Carroll County, Maryland

Science.gov (United States)

Conger, Randall W.

1997-01-01

Between April 23, 1996, and June 21, 1996, the U.S. Environmental Protection Agency contracted Haliburton-NUS, Inc., to drill four clusters of three monitoring wells near the Keystone Sanitation Superfund Site. The purpose of the wells is to allow monitoring and sampling of shallow, intermediate, and deep waterbearing zones for the purpose of determining the horizontal and vertical distribution of any contaminated ground water migrating from the Keystone Site. Twelve monitoring wells, ranging in depth from 50 to 397.9 feet below land surface, were drilled in the vicinity of the Keystone Site. The U.S. Geological Survey conducted borehole-geophysical logging and determined, with geophysical logs and other available data, the ideal intervals to be screened in each well. Geophysical logs were run on four intermediate and four deep wells, and a caliper log only was run on shallow well CL-AD-173 (HN-1S). Interpretation of geophysical logs and existing data determined the placement of screens within each borehole.

Neutron borehole logging correction technique

International Nuclear Information System (INIS)

Goldman, L.H.

1978-01-01

In accordance with an illustrative embodiment of the present invention, a method and apparatus is disclosed for logging earth formations traversed by a borehole in which an earth formation is irradiated with neutrons and gamma radiation produced thereby in the formation and in the borehole is detected. A sleeve or shield for capturing neutrons from the borehole and producing gamma radiation characteristic of that capture is provided to give an indication of the contribution of borehole capture events to the total detected gamma radiation. It is then possible to correct from those borehole effects the total detected gamma radiation and any earth formation parameters determined therefrom

Use of borehole and surface geophysics to investigate ground-water quality near a road-deicing salt-storage facility, Valparaiso, Indiana

Science.gov (United States)

Risch, M.R.; Robinson, B.A.

2001-01-01

Borehole and surface geophysics were used to investigate ground-water quality affected by a road-deicing salt-storage facility located near a public water-supply well field. From 1994 through 1998, borehole geophysical logs were made in an existing network of monitoring wells completed near the bottom of a thick sand aquifer. Logs of natural gamma activity indicated a uniform and negligible contribution of clay to the electromagnetic conductivity of the aquifer so that the logs of electromagnetic conductivity primarily measured the amount of dissolved solids in the ground water near the wells. Electromagneticconductivity data indicated the presence of a saltwater plume near the bottom of the aquifer. Increases in electromagnetic conductivity, observed from sequential logging of wells, indicated the saltwater plume had moved north about 60 to 100 feet per year between 1994 and 1998. These rates were consistent with estimates of horizontal ground-water flow based on velocity calculations made with hydrologic data from the study area.

Use of improved hydrologic testing and borehole geophysical logging methods for aquifer characterization

International Nuclear Information System (INIS)

Newcomer, D.R.; Hall, S.H.; Vermeul, V.R.

1996-01-01

Depth-discrete aquifer information was obtained using recently developed adaptations and improvements to conventional characterization techniques. These improvements included running neutron porosity and bulk density geophysical logging tools through a cased hole, performing an enhanced point-dilution tracer test for monitoring tracer concentration as a function of time and depth, and using pressure derivatives for diagnostic and quantitative analysis of constant rate discharge test data. Data results from the use of these techniques were used to develop a conceptual model of a heterogeneous aquifer. Depth-discrete aquifer information was required to effectively design field-scale deployment and monitoring of an in situ bioremediation technology. The bioremediation study site is located on the US Department of Energy's Hanford site. The study is being conducted by the Pacific Northwest National Laboratory to demonstrate in situ bioremediation of carbon tetrachloride (CCl 4 ). Geophysical logging and point-dilution tracer test results provided the relative distribution of porosity and horizontal hydraulic conductivity, respectively, with depth and correlated well. Hydraulic pumping tests were conducted to estimate mean values for transmissivity and effective hydraulic conductivity. Tracer test and geophysical logging results indicated that ground water flow was predominant in the upper approximate 10 feet of the aquifer investigated. These results were used to delineate a more representative interval thickness for estimating effective hydraulic conductivity. Hydraulic conductivity, calculated using this representative interval, was estimated to be 73 ft/d, approximately three times higher than that calculated using the full length of the screened test interval

Geophysical logging and thermal imaging near the Hemphill Road TCE National Priorities List Superfund site near Gastonia, North Carolina

Science.gov (United States)

Antolino, Dominick J.; Chapman, Melinda J.

2017-03-27

Borehole geophysical logs and thermal imaging data were collected by the U.S. Geological Survey near the Hemphill Road TCE (trichloroethylene) National Priorities List Superfund site near Gastonia, North Carolina, during August 2014 through February 2015. In an effort to assist the U.S. Environmental Protection Agency in the development of a conceptual groundwater model for the assessment of current contaminant distribution and future migration of contaminants, surface geological mapping and borehole geophysical log and thermal imaging data collection, which included the delineation of more than 600 subsurface features (primarily fracture orientations), was completed in five open borehole wells and two private supply bedrock wells. In addition, areas of possible groundwater discharge within a nearby creek downgradient of the study site were determined based on temperature differences between the stream and bank seepage using thermal imagery.

Evaluation of geophysical borehole studies

International Nuclear Information System (INIS)

Brotzen, O.; Duran, O.; Magnusson, K.Aa.

Four studies concerning geophysical investigations and TV inspection in boreholes in connection with KBS studies at Finnsjoe, Karlshamn, Kraakemaala and Stripa and PRAV's studies at Studsvik have been evaluated. This has led to proposals concerning the choice of instruments and methods for future studies and a review of future work required. The evaluation has shown that the following borehole measurements are of primary interest in the continued work: Determinations of temperature and resistivity of the borehole liquid, resistance and resistivity measurements, SP, Sonic, Caliper and VLF. TV inspection, IP and gamma-gamma should also be included in the arsenal of available test methods.(author)

Method and apparatus for logging inclined earth boreholes

International Nuclear Information System (INIS)

Youmans, A.H.

1981-01-01

An improved technique is provided for comparing the velocity of an elongated well logging instrument traversing an inclined earth borehole with the playout velocity of the well logging cable at the earth's surface to control both the cable hoist drum rotation and the rate of movement of the subsurface instrument and thus insure cable playout is in equilibrium with the logging instrument movement. Method and apparatus are described for detecting any reduction in movement of the logging instrument through the borehole and for reducing the velocity of the logging cable playout in response thereto by reducing drum rotation. Further, when the velocity of cable playout slows to a preselected value, a monitoring circuit generates control signals which actuate a means of power attached to or integral with the logging instrument which, upon initiation, apply a force to move the logging instrument upward or downward within the borehole

A borehole fluid conductivity logging method for the determination of fracture inflow parameters

International Nuclear Information System (INIS)

Tsang, C.F.; Hufschmied, P.

1988-01-01

It is of much current interest to determine the flow characteristics of fractures intersecting a wellbore in order to provide data in the estimation of the hydrologic behavior of fractured rocks. In particular the fluid inflow rates from the fractures into the wellbore are important quantities to measure. However often these inflows are at very low rates. In addition very often one finds that only a few percent of the fractures identified by core inspection and geophysical logging are water-conducting fractures, the rest being closed, clogged or isolated from the water flow system. A new method has been developed to locate water-conducting fractures and obtain fracture inflow parameters by means of a time sequence of electric conductivity logs of the borehole fluid. The physical basis of the analysis method is discussed. The procedure is applied to an existing set of data, which shows initiation and growth of nine conductivity peaks in a 900-m section of a 1690-m borehole, corresponding to nine waterconducting fractures intersecting the borehole. We are able to match all nine peaks and determine the flow rates from these fractures. A discussion is given on the applicability of this technique in the context of a borehole testing program. (author) 18 refs., 30 figs., 5 tabs

Borehole logging system

International Nuclear Information System (INIS)

Allen, L.S.

1988-01-01

A radioactive borehole logging tool employs an epithermal neutron detector having a neutron counter surrounded by an inner thermal neutron filter and an outer thermal neutron filter. Located between the inner and outer filters is a neutron moderating material for extending the lifetime of epithermal neutrons to enhance the counting rate of such epithermal neutrons by the neutron counter

Observations from borehole dilution logging experiments in fractured crystalline rock under variable hydraulic conditions

Science.gov (United States)

Harte, Philip T.; Anderson, Alton; Williams, John H.

2014-01-01

Identifying hydraulically active fractures in low permeability, crystalline-bedrock aquifers requires a variety of geophysical and hydrogeophysical borehole tools and approaches. One such approach is Single Borehole Dilution Tests (SBDT), which in some low flow cases have been shown to provide greater resolution of borehole flow than other logging procedures, such as vertical differential Heat Pulse Flowmeter (HPFM) logging. Because the tools used in SBDT collect continuous profiles of water quality or dye changes, they can identify horizontal flow zones and vertical flow. We used SBDT with a food grade blue dye as a tracer and dual photometer-nephelometer measurements to identify low flow zones.SBDT were conducted at seven wells with open boreholes (exceeding 300 ft). At most of the wells HPFM logs were also collected. The seven wells are set in low-permeability, fractured granite and gneiss rocks underlying a former tetrachloroeythylene (PCE) source area at the Savage Municipal Well Superfund site in Milford, NH. Time series SBDT logs were collected at each of the seven wells under three distinct hydraulic conditions: (1) ambient conditions prior to a pump test at an adjacent well, (2) mid test, after 2-3 days of the start of the pump test, and (3) at the end of the test, after 8-9 days of the pump test. None of the SBDT were conducted under pumping conditions in the logged well. For each condition, wells were initially passively spiked with blue dye once and subsequent time series measurements were made.Measurement accuracy and precision of the photometer tool is important in SBDT when attempting to detect low rates of borehole flow. Tests indicate that under ambient conditions, none of the wells had detectable flow as measured with HPFM logging. With SBDT, 4 of the 7 showed the presence of some very low flow. None of 5 (2 of the 7 wells initially logged with HPFM under ambient conditions were not re-logged) wells logged with the HPFM during the pump test had

Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

Energy Technology Data Exchange (ETDEWEB)

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

2010-01-15

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

Aespoe Hard Rock Laboratory. BIPS logging in borehole KAS09

International Nuclear Information System (INIS)

Gustafsson, Jaana; Gustafsson, Christer

2010-01-01

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

Integrating geophysical and hydrochemical borehole-log measurements to characterize the Chalk aquifer, Berkshire, United Kingdom

Science.gov (United States)

Schürch, Marc; Buckley, David

2002-09-01

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

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

Science.gov (United States)

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

2014-01-01

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

The use of borehole geophysical logs and hydrologic tests to characterize plutonic rock for nuclear fuel waste disposal

International Nuclear Information System (INIS)

Davison, C.C.

1984-05-01

The selection of an igneous rock body for the disposal of nuclear fuel waste will likely require the drilling and testing of a number of deep investigative boreholes in the rock body. Although coring of at least one hole at each Research Area will be essential, methods for making in situ geophysical and hydrological measurements can substitute for widespread coring and result in significant savings in time and money. A number of borehole methods have been applied to the investigation of plutonic rocks at Whiteshell Nuclear Research Establishment and Chalk River Nuclear Laboratories in Canada

Handbook on nuclear data for borehole logging and mineral analysis

International Nuclear Information System (INIS)

1993-01-01

In nuclear geophysics, an extension of the nuclear data available for reactor and shielding calculations, is required. In general, the problems and the methods of attack are the same, but in nuclear geophysics the environment is earth materials, with virtually all the natural elements in the Periodic Table involved, although not at the same time. In addition, the geometrical configurations encountered in nuclear geophysics are very different from those associated with reactor and shielding design, and they can impose a different demand on the required accuracy of the nuclear data and on the dependence on the calculational approach. Borehole logging is a very good example, since an experimental investigation aimed at varying only one parameter (e.g. moisture content) whilst keeping all the others constant in a geologically complex system that effectively exhibits 'infinite geometry' for neutrons and γ rays is virtually impossible. An increasingly important are of nuclear geophysics is the on-line analysis of natural materials such as coal (e.g. C, H, O, Al, Si, Ca, Fe, Cl, S, N,) the raw materials of the cement industry (S, Na, K, Al, Si, Ca, Fe, Mn, Ti, P, Mg, F, O), and mined ores of Fe, Al, Mn, Cu, Ni, Ag and Au, amongst others. Refs, figs and tabs

Site characterization and validation - geophysical single hole logging. Stage 1

International Nuclear Information System (INIS)

Fridh, B.

1987-12-01

Five 'boundary boreholes' have been drilled for preliminary characterization of a previously unexplored site at the 360 m level in the Stripa mine. Three of these boreholes are directed towards the North in the mine coordinate system, while two are directed towards the West. Furthermore, a vertical hole has been drilled at the end of the 3D-migration drift. To adequately describe the rock mass in the vicinity of these boreholes, a comprehensive program utilizing a large number of geophysical borehole methods has been carried out. The specific geophysical character of the rock mass and the major deformed units distinguished in the boreholes are recognized, and in certain cases also correlated between the boreholes. (orig.)

Borehole Logging for Uranium by Gamma-Ray Spectrometry

DEFF Research Database (Denmark)

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

1980-01-01

The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium-iodide, and the photo......The resources in a large syngenetic deposit of low-grade uranium (U) ore with thorium at Kvanefjeld, South Greenland, were evaluated by spectrometric gamma-ray logging of 23 boreholes, 46 mm in diameter and 200 m deep. The borehole probe's detector contained 22 cm3 of sodium...... of the spectrometer system were determined by calculating the average number of U and thorium (Th) counts per meter of borehole and comparing these with the U-Th concentrations in 1-m sections of analyzed drill core. The sensitivity and the background count rate in the uranium window varied appreciably from one hole...

The assessment of the geophysical investigations of boreholes

International Nuclear Information System (INIS)

Brotzen, O.; Duran, O.; Magnusson, K.-Aa.

1980-02-01

Four geophysical investigations and a televiewer inspection of boreholes have been evaluated in connection with the examinations at Finnsjoen, Karlshamn, Kraakemaala, Stripa and Studsvik. A cooperative assessment of the systems for the measurement of boreholes by Lawrence Berkeley Laboratories and the Geological Survey of Sweden has been made at Stripa. The following methods should be selected for future measurements: determination of the resistivity and temperature of the fluid in the borehole, determination of the resistivity and temperature of the fluid in the borehole, determination of the self-potential, resistivity and resistance of the rock as well as the measurement of sonar waves, the diameter of the borehole and the very low frequency effects. (G.B.)

Borehole geophysical and flowmeter data for eight boreholes in the vicinity of Jim Woodruff Lock and Dam, Lake Seminole, Jackson County, Florida

Science.gov (United States)

Clarke, John S.; Hamrick, Michael D.; Holloway, O. Gary

2011-01-01

Borehole geophysical logs and flowmeter data were collected in April 2011 from eight boreholes to identify the depth and orientation of cavernous zones within the Miocene Tampa Limestone in the vicinity of Jim Woodruff Lock and Dam in Jackson County, Florida. These data are used to assess leakage near the dam. Each of the eight boreholes was terminated in limestone at depths ranging from 84 to 104 feet. Large cavernous zones were encountered in most of the borings, with several exceeding 20-inches in diameter. The cavernous zones generally were between 1 and 5 feet in height, but a cavern in one of the borings reached a height of about 6 feet. The resistivity of limestone layers penetrated by the boreholes generally was less than 1,000 ohm-meters. Formation resistivity near the cavernous zones did not show an appreciable contrast from surrounding bedrock, probably because the bedrock is saturated, owing to its primary permeability. Measured flow rates in the eight boreholes determined using an electromagnetic flowmeter were all less than ±0.1 liter per second. These low flow rates suggest that vertical hydraulic gradients in the boreholes are negligible and that hydraulic head in the various cavernous zones shows only minor, if any, variation.

Pulsed neutron uranium borehole logging with prompt fission neutrons

International Nuclear Information System (INIS)

Bivens, H.M.; Smith, G.W.; Jensen, D.H.

1976-01-01

The gross count natural gamma log normally used for uranium borehole logging is seriously affected by disequilibrium. Methods for the direct measurement of uranium, such as neutron logging, which are not affected by disequilibrium have been the object of considerable effort in recent years. This paper describes a logging system for uranium which uses a small accelerator to generate pulses of 14 MeV neutrons to detect and assay uranium by the measurement of prompt fission neutrons in the epithermal energy range. After an initial feasibility study, a prototype logging probe was built for field evaluation which began in January 1976. Physical and operational characteristics of the prototype probe, the neutron tube-transformer assembly, and the neutron tube are described. In logging operations, only the epithermal prompt fission neutrons detected between 250 microseconds to 2500 microseconds following the excitation neutron pulse are counted. Comparison of corrected neutron logs with the conventional gross count natural gamma logs and the chemical assays of cores from boreholes are shown. The results obtained with this neutron probe clearly demonstrate its advantages over the gross count natural gamma log, although at this time the accuracy of the neutron log assay is not satisfactory under some conditions. The necessary correction factors for various borehole and formation parameters are being determined and, when applied, should improve the assay accuracy

Borehole geophysical measurements for Hole UE25a-3, Nevada Test Site, Nuclear Waste Isolation Program

International Nuclear Information System (INIS)

Daniels, J.J.; Scott, J.H.

1980-01-01

Borehole geophysical measurements made in drill hole UE25a-3 with a US Geological Survey research well-logging truck are presented in this paper. The purpose of these logging measurements is to provide in-situ physical properties information that is not commercially available on drill hole UE25a-3. Well logs are presented in this paper for dual-detector density, normal resistivity, gamma-ray, neutron-neutron, induced polarization, and magnetic susceptibility measurements. These data are analyzed correlations with the core lithology. Hole-to-surface measurements made from drill hole UE25a-3 indicate the presence of two resistive bodies at depth. The deeper resistive anomaly may be related to a granitic intrusion

Practical borehole logging procedures for mineral exploration, with emphasis on uranium

International Nuclear Information System (INIS)

1986-01-01

Borehole logging is a basic tool in the exploration for and delineation of uranium deposits. This manual describes recommended procedures for carrying out borehole logging, concentrating on practical aspects of the operation of interest to those actually involved in day-to-day field work. The book begins with a discussion of boreholes and then deals with gamma ray logging as the main method of interest. Information is also provided on other techniques including resistance, spontaneous potential, density and neutron logging. Field procedures are described, and examples of logs and interpretations are given. The appendices provide information on calibration procedures and correction factors, a glossary of useful terms and some relevant basic data regarding drill holes and drilling

Nuclear borehole logging for oil exploration

International Nuclear Information System (INIS)

Oelgaard, P.L.

1989-01-01

Reactor physics can be applied to the logging of boreholes for the exploration of oil and gas and the results obtained can be interpreted more correctly by use of reactor physics models, e.g. one-dimensional multi-group diffusion theory adapted for gamma quanta. The standard nuclear logging tools are: natural gamma, gamma density, neutron porosity and the pulsed-neutron tool. The models and interpretation procedures are discussed. 1 fig

Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada

Science.gov (United States)

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

2001-01-01

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

Quantitative and qualitative applications of the neutron-gamma borehole logging

International Nuclear Information System (INIS)

Charbucinski, J.; Aylmer, J.A.; Eisler, P.L.; Borsaru, M.

1989-01-01

Two neutron-γ borehole logging applications are described. In a quantitative application of the prompt-gamma neutron-activation analysis (PGNAA) technique, research was carried out both in the laboratory and at a mine to establish a suitable borehole logging technology for manganese-grade predictions. As an example of the qualitative application of PGNAA, the use of this method has been demonstrated for the determination of lithology. (author)

Quantitative and qualitative applications of the neutron-gamma borehole logging

International Nuclear Information System (INIS)

Charbucinski, J.; Eisler, P.L.; Borsaru, M.; Aylmer, J.A.

1990-01-01

Two examples of neutron-gamma borehole logging application are described. In the quantitative application of the PGNAA technique, research was carried out both in the laboratory and at a mine to establish a suitable borehole logging technology for Mn-grade predictions. As an example of qualitative application of PGNAA, use of this method has been demonstrated for determination of lithology. (author). 4 refs, 10 figs, 7 tabs

Analysis of borehole-radar reflection logs from selected HC boreholes at the Project Shoal area, Churchill County, Nevada; TOPICAL

International Nuclear Information System (INIS)

Lane, J.W. Jr.; Joesten, P.K.; Pohll, Greg; Mihevic, Todd

2001-01-01

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

Digitization, correction, and standardization of geophysical logs from deep boreholes of Central New York State. Final technical report

International Nuclear Information System (INIS)

Robinson, J.E.

1981-07-01

Digitization and standardization of suitable logs are provided from wells located in the area of Central New York that had been under consideration as a possible site for the disposal of radioactive waste. Digitized logs included those with geophysical parameters that could be analyzed for formation porosity and lithology and in which the log interval was sufficient to evaluate formation parameters. Digitizing equipment was purchased, interfaced, and necessary software was written and documented. Magnetic tapes and hard copy playbacks of all digitized well logs are being forwarded to the Department of Energy repository at Battelle Memorial Institute for use in future projects

Acoustic and Optical Televiewer Borehole Logging

International Nuclear Information System (INIS)

Ahmad Hasnulhadi Che Kamaruddin; Nik Marzukee Nik Ibrahim; Zaidi Ibrahim; Nurul Wahida Ahmad Khairuddin; Azmi Ibrahim

2016-01-01

This review paper is focused on Borehole Televiewer. Borehole Televiewer or (BHTV) was used to obtain high-resolution acoustical images from the borehole wall. A probe with a high resolution downward looking camera is used. The camera has specific optics (a conical mirror with a ring of bulbs) with just one shot needed to capture the entire borehole circumference as a 360 panoramic view. Settings similar to traditional cameras (exposure, quality, light, frame rate and resolution) make it effective in almost any type of borehole fluid. After each shot, a series of horizontal pixel strings are acquired, giving a rasterized RGB picture in real-time which is transmitted to the console and finally to a monitor. The orientation device embedded in the tool, which is made of 3 inclinometers and 3 magnetometers, allows the inclination and azimuth of the probe to be computed in real-time, correctly orienting the borehole images. Besides, Acoustic and Optical Televiewer has been introduced as its advanced in technological research. Its logging has been successfully applied to geotechnical investigations and mineral exploration (Schepers et al., 2001) due to advances in beam focusing, increased dynamic range, digital recording techniques, and digital data processing (Schepers, 1991). Thus, this paper will go through to the basic principle of (BHTV) as one type of data collection today. (author)

Core-logs of the vertical borehole V2

International Nuclear Information System (INIS)

Carlsson, L.; Egerth, T.; Westlund, B.; Olsson, T.

1982-08-01

In the hydrogeological programme of the Stripa Project, borehole V2 was prolonged to a final depth of 822 m. The previous core from 0-471.4 m was relogged. The drill core was logged with regard to rock characteristics, fracture frequency, dipping and filling. The results are presented as core-logs and fracture diagrams. Borehole V2 shows similar characteristics as found in other drillings in the Stripa Mine. It penetrates Stripa granite to its full depth. recorded fractures shows a clear predominance of medium-steep fractures, while flat-lying fractures are more sparsly occuring, a fact which is even more pronounced below 400 m depth. Due to the vertical direction of the borehole, steeply dipping fractures are underestimated in the core. The mean fracture frequency, related to the total length of the core, is 2.1 fractures/m. Chlorite, calcite and epidote are the dominating coating minerals in the fractures, each making up about 25-30 percent of all coated fractures. (Authors)

Bench top and portable mineral analysers, borehole core analysers and in situ borehole logging

International Nuclear Information System (INIS)

Howarth, W.J.; Watt, J.S.

1982-01-01

Bench top and portable mineral analysers are usually based on balanced filter techniques using scintillation detectors or on low resolution proportional detectors. The application of radioisotope x-ray techniques to in situ borehole logging is increasing, and is particularly suited for logging for tin and higher atomic number elements

Cause of depth error of borehole logging and its correction

International Nuclear Information System (INIS)

Iida, Yoshimasa; Ikeda, Koki; Tsuruta, Tadahiko; Ito, Hiroaki; Goto, Junichi.

1996-01-01

Data by borehole logging can be used for detailed analysis of geological structures. Depths measured by portable borehole loggers commonly shift a few meters on the level of 400 to 500 meters deep. Therefore, the cause of depth error has to be recognized to make proper corrections for detailed structural analysis. Correlation between depths of drill core and in-rod radiometric logging has been performed in detail on exploration drill holes in the Athabasca basin, Canada. As a result, a common tendency of logging depth shift has been recognized, and an empirical formula (quadratic equation) for this has been obtained. The physical meaning of the formula and the cause of the depth error has been considered. (author)

Interpretation of wireline geophysical logs. ERDA No. 9 stratigraphic test borehole, DOE WIPP Site, Eddy County, New Mexico

International Nuclear Information System (INIS)

Griswold, G.B.; McWhirter, V.C.

1981-02-01

A stratigraphic core hole known as ERDA No. 9 was drilled at the approximate center of the Waste Isolation Pilot Plant (WIPP) site located east of Carlsbad, New Mexico. The hole was continuously cored from 1090 to 2887 feet, the total depth of the hole. A suite of 20 wireline geophysical logs were made under open hole conditions over the cored interval. Recording in the field was by analog strip charts. The records were subsequently digitized at 0.5 foot intervals with the data placed on magnetic tape. A simple computer program was devised to interpret rock type and calculate elastic properties based on the digital data. All of the data is available in convenient digital form, and additional computer-assisted analysis is now possible to describe the detailed stratigraphy of the evaporites penetrated in ERDA No. 9. The analysis performed thus far is in excellent agreement with physical examination of the core. The main advantage of correlating the wireline geophysical logs with core is to provide a better basis for using wireline logs to describe rock conditions either in future holes drilled by the simpler rotary method or where core has been lost in cored holes

Geostatistical methods for rock mass quality prediction using borehole and geophysical survey data

Science.gov (United States)

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

2015-12-01

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

Integrated core-log interpretation of Wenchuan earthquake Fault Scientific Drilling project borehole 4 (WFSD-4)

Science.gov (United States)

Konaté, Ahmed Amara; Pan, Heping; Ma, Huolin; Qin, Zhen; Traoré, Alhouseiny

2017-08-01

Understanding slip behavior of active fault is a fundamental problem in earthquake investigations. Well logs and cores data provide direct information of physical properties of the fault zones at depth. The geological exploration of the Wenchuan earthquake Scientific Fault drilling project (WFSD) targeted the Yingxiu-Beichuan fault and the Guanxian Anxian fault, respectively. Five boreholes (WFSD-1, WFSD-2, WFSD-3P WFSD-3 and WFSD-4) were drilled and logged with geophysical tools developed for the use in petroleum industry. WFSD-1, WFSD-2 and WFSD-3 in situ logging data have been reported and investigated by geoscientists. Here we present for the first time, the integrated core-log studies in the Northern segment of Yingxiu-Beichuan fault (WFSD-4) thereby characterizing the physical properties of the lithologies(original rocks), fault rocks and the presumed slip zone associated with the Wenchuan earthquake. We also present results from the comparison of WFSD-4 to those obtained from WFSD-1, WFSD-3 and other drilling hole in active faults. This study show that integrated core-log study would help in understanding the slip behavior of active fault.

Fibre optical gyroscopes in borehole logging; Einsatz faseroptischer Kreisel Technologien in der Bohrlochgeophysik

Energy Technology Data Exchange (ETDEWEB)

Stoll, J.B. [BGR, Hannover (Germany); Leven, M.; Steveling, E. [Inst. fuer Geophysik, Goettingen (Germany)

2003-07-01

A fibre optical gyroscope was installed in a borehole magnetometer in the framework of a DFG-funded pilot project carried out in co-operation with the Institute of Geophysics of Goettingen University. The measuring system was used in an ocean log in the NW Pacific for measuring the remnant section of the magnetic field of the strongly magnetic ocean crust and its direction. the system is completely independent of the magnetic field, which is not required as an orientation aid. Further applications are envisaged in online measuring of borehole or cavern geometries and subsequent orientation of borehole wall images using imaging procedures like FMS, FMI, or borehole televiewer. [German] Um die Drehwinkel eines im Raum rotierenden Messsystems zu erfassen, gibt es verschiedene Messtechniken, mit denen die Raumlage eines Messsystems gegenueber einem Inertialsystem bestimmt werden kann. Eine Gruppe von Drehratensensoren sind die sogenannten optischen Kreisel, die im folgenden naeher besprochen werden. Ein solcher faseroptischer Drehratensensor wurde im Rahmen eines von der DFG gefoerderten Pilotprojektes in Zusammenarbeit mit dem Geophysikalischen Institut der Universitaet Goettingen in ein Bohrlochmagnetometer eingebaut. Ziel des Pilotprojektes war es zu testen, mit welcher Genauigkeit die Horizontalkomponenten des Magnetometers mithilfe des faseroptischen Kreisels in Bezug auf ein erdfestes Koordinatensystem ausgerichtet werden koennen. Dieses Messsystem wurde in einer Ozeanbohrung im NW-Pazifik eingesetzt, mit dem Ziel den remanente Anteil des Magnetfeldes der stark magnetischen ozeanischen Kruste und dessen Richtung zu bestimmen. Mit diesem Sensor steht ein Messverfahren zur Verfuegung, das vom Magnetfeld als Orientierungshilfe vollstaendig unabhaengig ist. Weitere Anwendungsmoeglichkeiten dieser Messtechnik sind die online Vermessung der Geometrie von Bohrungen oder Kavernen und die nachtraegliche Orientierung von Abbildungen der Bohrlochwand mittels bildgebender

Fiber-optic data-transmission system for borehole logging. Final report. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Gould, G.

1981-01-01

The purpose of the system is to provide signal transmission media for transmission of digital data from a borehole logging probe (and associated processor-electronics) to a borehole logging truck at the surface. This fiber optic transmission system is specifically designed for use on the Bendix Field Engineering Corp. (BFEC) R and D logging truck

Characterization of reservoir fractures using conventional geophysical logging

Directory of Open Access Journals (Sweden)

Paitoon Laongsakul

2011-04-01

Full Text Available In hydrocarbon exploration fractures play an important role as possible pathways for the hydrocarbon flow and bythis enhancing the overall formation’s permeability. Advanced logging methods for fracture analysis, like the boreholeacoustic televiewer and Formation Microscanner (FMS are available, but these are additional and expensive tools. However,open and with water or hydrocarbon filled fractures are also sensitive to electrical and other conventional logging methods.For this study conventional logging data (electric, seismic, etc were available plus additional fracture information from FMS.Taking into account the borehole environment the results show that the micro-spherically focused log indicates fractures byshowing low resistivity spikes opposite open fractures, and high resistivity spikes opposite sealed ones. Compressional andshear wave velocities are reduced when passing trough the fracture zone, which are assumed to be more or less perpendicularto borehole axis. The photoelectric absorption curve exhibit a very sharp peak in front of a fracture filled with bariteloaded mud cake. The density log shows low density spikes that are not seen by the neutron log, usually where fractures,large vugs, or caverns exist. Borehole breakouts can cause a similar effect on the logging response than fractures, but fracturesare often present when this occurs. The fracture index calculation by using threshold and input weight was calculatedand there was in general a good agreement with the fracture data from FMS especially in fracture zones, which mainlycontribute to the hydraulic system of the reservoir. Finally, the overall results from this study using one well are promising,however further research in the combination of different tools for fracture identification is recommended as well as the useof core for further validation.

Quantitative geological modeling based on probabilistic integration of geological and geophysical data

DEFF Research Database (Denmark)

Gulbrandsen, Mats Lundh

In order to obtain an adequate geological model of any kind, proper integration of geophysical data, borehole logs and geological expert knowledge is important. Geophysical data provide indirect information about geology, borehole logs provide sparse point wise direct information about geology...... entitled Smart Interpretation is developed. This semi-automatic method learns the relation between a set of data attributes extracted from deterministically inverted airborne electromagnetic data and a set of interpretations of a geological layer that is manually picked by a geological expert...

Core-logs of borehole VI down to 505 m

International Nuclear Information System (INIS)

Carlsson, L.; Olsson, T.; Stejskal, V.

1981-01-01

In the hydrogeological program of the Stripa project the vertical borehole V1 has been drilled 505.5 m. The drillcore has been logged with regard to rock characteristic, fracture frequency, dipping and filling. The results presented as cumulative fracture diagram have formed the base for subdivision of the borehole according to fracture frequency. The variation in the fracture dipping was also taken into account. Chlorite is the most common of the infilling material in the fractures. For the borehole 0-466 m the average fracture frequency is 1.46 fractures/m. Below 466 m the core is highly fractured and crushed indicating that the borehole has entered a crushed zone. Because of this the drilling is temporarily stopped. (Auth.)

Development of a geophysical methodology from boreholes for the study of granitic formation storage site

International Nuclear Information System (INIS)

Le Masne, D.

1983-01-01

The aim of this work is the characterization of the fracturation of a granitic formation by the examination of borehole environment. Two types of methods are used. Methods using one borehole only: well logging (electrical and nuclear). Didier logs (electric dipole-dipole), Eric probes (electromagnetic dipole-dipole) and methods between boreholes (grounding). These methods were applied to two boreholes of 500m and 1000 meters drilled into granite at Auriat (France)

Geophysical investigations of the Romuvaara area, Finland

International Nuclear Information System (INIS)

Saksa, P.; Paananen, M.

1991-06-01

In the study area of Romuvaara, investigations have been carried out during 1987 - 90 with the aim of finding out whether the polyphasically deformed Precambrian gneiss complex is suitable for the final disposal of spent nuclear fuel. The bedrock has been studied by geological, geophysical, geohydrological and geochemical methods. Airborne, ground and borehole geophysical surveys were used in studying the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre. Airborne surveys (magnetic, radiometric and two electromagnetic methods) and ground surveys (VLF and VLF-R, magnetic and soil radar methods) were useful in distinguishing the metadiabases, amphibolites and granodiorites from the less magnetized migmatites. The electromagnetic and seismic refraction surveys were used in locating crushed and fractured zones. The rock type distribution was studied by single-hole logging of susceptibility, natural γ radiation and radiometric γ-γ -density. Electrical and acoustic logging served the mapping of fractures and the interpretation of water injection tests. The flow conditions in the boreholes were studied by fluid logging and tube-wave sounding. The rock volume surrounding the boreholes was mapped by borehole radar with a frequency of 22 MHz. The upper parts of the boreholes were also studied by vertical radar profiling (VRP). Larger volumes of rock were mapped by vertical seismic profiling (VSP) using 4 - 5 transmitter shotholes per borehole

Accuracy and borehole influences in pulsed neutron gamma density logging while drilling.

Science.gov (United States)

Yu, Huawei; Sun, Jianmeng; Wang, Jiaxin; Gardner, Robin P

2011-09-01

A new pulsed neutron gamma density (NGD) logging has been developed to replace radioactive chemical sources in oil logging tools. The present paper describes studies of near and far density measurement accuracy of NGD logging at two spacings and the borehole influences using Monte-Carlo simulation. The results show that the accuracy of near density is not as good as far density. It is difficult to correct this for borehole effects by using conventional methods because both near and far density measurement is significantly sensitive to standoffs and mud properties. Copyright © 2011 Elsevier Ltd. All rights reserved.

Comparative study of geological, hydrological, and geophysical borehole investigations

International Nuclear Information System (INIS)

Magnusson, K.A.; Duran, O.

1984-09-01

The understanding of the permeability of the bedrock can be improved by supplementing the results of the water injection tests with information from core mapping, TB-inspection and borehole geophysics. The comparison between different borehole investigations encompasses core mapping, TV-inspection and various geophysical bore hole measurements. The study includes data from two different study areas, namely Kraakemaala and Finnsjoen. In these two areas, extensive geological, hydrological and geophysical investigation have been carried out. The fractures and microfractures in crystalline rock constitute the main transport paths for both groundwater and electric currents. They will therefore govern both the permeability and the resistivity of the rock. In order to get a better understanding of the influence of fractures on permeability and resistivity, a detailed comparison has been made between the hydraulic conductivity, respectively, and the character of fractures in the core and the borehole wall. The fractures show very large variations in hydraulic conductivity. Microfractures and most of the thin fractures have no measurable hydraulic conductivity (in this case -9 m s -1 ), while test sections which contain a single isloated fracture can have no measurable, to rather high hydraulic conductivities (> 10 -7 m s -1 ). Wide fracture zones often have hydraulic conductivities which vary from very low (less than 2 x 10 -9 m s -1 ) to high values (10 -5 m s -1 ). This indicates that the hydraulic conductivity is governed by a few discrete fractures. The resistivity shows a continous variation in the range 1,000- 100,000 ohm-m and a relatively poor correlation with hydraulic conductivities. The observed difference is considered to the effect of restriction of water flow on a few channels, while electric surface condition, i.e. current transport through thin water films, makes current transport possible through fractures with very small aperatures. (Author)

Magnetotelluric data collected near geophysically logged boreholes in the Espa?ola and Middle Rio Grande basins, New Mexico

Science.gov (United States)

Williams, Jackie M.; Rodriguez, Brian D.

2006-01-01

The Santa Fe region is growing rapidly. The Santa Fe Group aquifer in the Espa?ola Basin is the main source of municipal water for the region, and water shortfalls could have serious consequences. Future growth and land management in the region depend on accurate assessment and protection of the region's ground-water resources. An important issue in managing the ground-water resources is a better understanding of the hydrogeology of the Tertiary Santa Fe Group. The Santa Fe Group includes the sedimentary deposits that fill the Rio Grande rift and contain the principal ground-water aquifers. The U.S. Geological Survey (USGS) is conducting a series of multidisciplinary studies of the Espa?ola Basin in northern New Mexico. Detailed geologic mapping, high-resolution airborne magnetic surveys, electromagnetic surveys, and hydrologic, lithologic, and hydro-geochemical data are being used to better understand the aquifer systems. Magnetotelluric (MT) surveys were completed as part of these studies. The primary purpose of the MT surveys was to map changes in electrical resistivity with depth that are related to differences in various rock types that help control the properties of aquifers in the region. Resistivity modeling of the MT data can be used to investigate buried structures related to the basic geologic framework of the study area. The purpose of this report is to release MT sounding data collected near geophysically logged boreholes in the study area, including the nearby Middle Rio Grande Basin. This MT data can be used in subsequent resistivity modeling. No interpretation of the data is included in this report.

Drilling, logging, and testing information from borehole UE-25 UZ number-sign 16, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Thamir, F.; Thordarson, W.; Kume, J.; Rousseau, J.; Cunningham, D.M. Jr.

1998-01-01

Borehole UE-25 UZ number-sign 16 is the first of two boreholes that may be used to determine the subsurface structure at Yucca Mountain by using vertical seismic profiling. This report contains information collected while this borehole was being drilled, logged, and tested from May 27, 1992, to April 22, 1994. It does not contain the vertical seismic profiling data. This report is intended to be used as: (1) a reference for drilling similar boreholes in the same area, (2) a data source on this borehole, and (3) a reference for other information that is available from this borehole. The reference information includes drilling chronology, equipment, parameters, coring methods, penetration rates, completion information, drilling problems, and corrective actions. The data sources include lithology, fracture logs, a list of available borehole logs, and depths at which water was recorded. Other information is listed in an appendix that includes studies done after April 22, 1994

About probabilistic integration of ill-posed geophysical tomography and logging data: A knowledge discovery approach versus petrophysical transfer function concepts illustrated using cross-borehole radar-, P- and S-wave traveltime tomography in combination with cone penetration and dielectric logging data

Science.gov (United States)

Paasche, Hendrik

2018-01-01

Site characterization requires detailed and ideally spatially continuous information about the subsurface. Geophysical tomographic experiments allow for spatially continuous imaging of physical parameter variations, e.g., seismic wave propagation velocities. Such physical parameters are often related to typical geotechnical or hydrological target parameters, e.g. as achieved from 1D direct push or borehole logging. Here, the probabilistic inference of 2D tip resistance, sleeve friction, and relative dielectric permittivity distributions in near-surface sediments is constrained by ill-posed cross-borehole seismic P- and S-wave and radar wave traveltime tomography. In doing so, we follow a discovery science strategy employing a fully data-driven approach capable of accounting for tomographic ambiguity and differences in spatial resolution between the geophysical tomograms and the geotechnical logging data used for calibration. We compare the outcome to results achieved employing classical hypothesis-driven approaches, i.e., deterministic transfer functions derived empirically for the inference of 2D sleeve friction from S-wave velocity tomograms and theoretically for the inference of 2D dielectric permittivity from radar wave velocity tomograms. The data-driven approach offers maximal flexibility in combination with very relaxed considerations about the character of the expected links. This makes it a versatile tool applicable to almost any combination of data sets. However, error propagation may be critical and justify thinking about a hypothesis-driven pre-selection of an optimal database going along with the risk of excluding relevant information from the analyses. Results achieved by transfer function rely on information about the nature of the link and optimal calibration settings drawn as retrospective hypothesis by other authors. Applying such transfer functions at other sites turns them into a priori valid hypothesis, which can, particularly for empirically

Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, March 1994 to June 1994

International Nuclear Information System (INIS)

Geslin, J.K.; Moyer, T.C.

1995-01-01

This report summarizes lithologic logging of core from boreholes at Yucca Mountain, Nevada, conducted from March 1994 to June 1994. Units encountered during logging include Quaternary-Tertiary alluvium and colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, and Tertiary Calico Hills Formation. Logging results are presented in a table of contact depths for core from unsaturated zone neutron (UZN) boreholes and graphic lithologic logs for core from north ramp geology (NRG) boreholes

Catalog of borehole lithologic logs from the 600 Area, Hanford Site

International Nuclear Information System (INIS)

Fecht, K.R.; Lillie, J.T.

1982-03-01

Rockwell Hanford Operations (Rockwell) geoscientists are studying the Hanford Site subsurface environment to assure safe management operations, disposal, and storage of radioactive waste. As part of this effort, geoscientists have collected geotechnical data from about 3000 boreholes drilled on the Hanford Site since the early 1900s. These boreholes have been used for subsurface geologic, hydrologic, and engineering investigation, water supply, ground-water monitoring, and natural gas production. This report is a catalog of all obtainable (about 800) lithologic logs from boreholes in a portion of the Hanford Site known as the 600 Area

Classification of lithological units based on geophysical borehole logging - data from the Stripa mine

International Nuclear Information System (INIS)

Triumf, C.A.

1992-06-01

At the Crosshole site, located at the 360 m level in the Stripa mine, six boreholes F1-F6 have been drilled in a fanlike fashion. To achieve further knowledge of the geological conditions in the rock volumes outside the major tectonized zones, a classification of the pseudo-lithology has been carried out using data from boreholes F3-F6. The analysis has been supported by determination of density and magnetic susceptibility on core samples from boreholes F1-F5. This study demonstrates that the bulk of the tectonically less disturbed rock, forming the matrix in a network of dominant tectonical features, can be considered as homogeneous according to the silicate density. Three volumes with deviating lithology have however been identified in more than one borehole. Furthermore narrow sections are encountered, showing mineralogical, and probably also, micro-structural deviations from the normal granite. These narrow sections are irregularly spread along the boreholes. Their irregular distribution and narrowness, prevents correlation between boreholes. The result of the lithology identification is displayed using a modified Briggs cube. The method used in this project is applicable in many stages of an investigation programme where different disciplines are co-operating and partly complex information must be passed between individuals. (au)

Deep Drilling Into the Chicxulub Impact Crater: Pemex Oil Exploration Boreholes Revisited

Science.gov (United States)

Fucugauchi, J. U.; Perez-Cruz, L.

2007-05-01

The Chicxulub structure was recognized in the 1940´s from gravity anomalies in oil exploration surveys by Pemex. Geophysical anomalies occur over the carbonate platform in NW Yucatan, where density and magnetic susceptibility contrasts with the carbonates suggested a buried igneous complex or basement uplift. The exploration program developed afterwards included several boreholes, starting with the Chicxulub-1 in 1952 and eventually comprising eight deep boreholes completed through the 1970s. The investigations showing Chicxulub as a large impact crater formed at the K/T boundary have relayed on the Pemex decades-long exploration program. Despite frequent reference to Pemex information, original data have not been openly available for detailed evaluation and incorporation with results from recent efforts. Logging data and core samples remain to be analyzed, reevaluated and integrated in the context of recent marine, aerial and terrestrial geophysical surveys and the drilling/coring projects of UNAM and ICDP. In this presentation we discuss the paleontological data, stratigraphic columns and geophysical logs for the Chicxulub-1 (1582m), Sacapuc-1 (1530m), Yucatan-6 (1631m) and Ticul-1 (3575m) boreholes. These boreholes remain the deepest ones drilled in Chicxulub and the only ones providing samples of the melt-rich breccias and melt sheet. Other boreholes include the Y1 (3221m), Y2 (3474m), Y4 (2398m) and Y5A (3003m), which give information on pre-impact stratigraphy and crystalline basement. We concentrate on log and microfossil data, stratigraphic columns, lateral correlation, integration with UNAM and ICDP borehole data, and analyses of sections of melt, impact breccias and basal Paleocene carbonates. Current plans for deep drilling in Chicxulub crater focus in the peak ring zone and central sector, with proposed marine and on-land boreholes to the IODP and ICDP programs. Future ICDP borehole will be located close to Chicxulub-1 and Sacapuc-1, which intersected

Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

KAUST Repository

Pardo, David

2013-02-13

We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method that delivers highly accurate solutions of linear visco-elasto-acoustic problems in the frequency domain. The analysis focuses on WL instruments equipped with monopole or dipole sources and LWD instruments with monopole excitation. Analysis of the main propagation modes obtained from frequency dispersion curves indicates that the additional high-order modes arising as a result of borehole-eccentricity interfere with the main modes (i.e., Stoneley, pseudo-Rayleigh and flexural). This often modifies (decreases) the estimation of shear and compressional formation velocities, which should be corrected (increased) to account for borehole-eccentricity effects. Undesired interferences between different modes can occur at different frequencies depending upon the properties of the formation and fluid annulus size, which may difficult the estimation of the formation velocities. © 2013 European Association of Geoscientists & Engineers.

Accuracy and borehole influences in pulsed neutron gamma density logging while drilling

Energy Technology Data Exchange (ETDEWEB)

Yu Huawei [College of Geo-Resources and Information, China University of Petroleum, Qingdao, Shandong 266555 (China); Center for Engineering Applications of Radioisotopes (CEAR), Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Sun Jianmeng [College of Geo-Resources and Information, China University of Petroleum, Qingdao, Shandong 266555 (China); Wang Jiaxin [Center for Engineering Applications of Radioisotopes (CEAR), Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States); Gardner, Robin P., E-mail: gardner@ncsu.edu [Center for Engineering Applications of Radioisotopes (CEAR), Department of Nuclear Engineering, North Carolina State University, Raleigh, NC 27695 (United States)

2011-09-15

A new pulsed neutron gamma density (NGD) logging has been developed to replace radioactive chemical sources in oil logging tools. The present paper describes studies of near and far density measurement accuracy of NGD logging at two spacings and the borehole influences using Monte-Carlo simulation. The results show that the accuracy of near density is not as good as far density. It is difficult to correct this for borehole effects by using conventional methods because both near and far density measurement is significantly sensitive to standoffs and mud properties. - Highlights: > Monte Carlo evaluation of pulsed neutron gamma-ray density tools. > Results indicate sensitivity of the tool to standoff and mudcake properties. > Accuracy of far spaced detector is better than near spaced.

Accuracy and borehole influences in pulsed neutron gamma density logging while drilling

International Nuclear Information System (INIS)

Yu Huawei; Sun Jianmeng; Wang Jiaxin; Gardner, Robin P.

2011-01-01

A new pulsed neutron gamma density (NGD) logging has been developed to replace radioactive chemical sources in oil logging tools. The present paper describes studies of near and far density measurement accuracy of NGD logging at two spacings and the borehole influences using Monte-Carlo simulation. The results show that the accuracy of near density is not as good as far density. It is difficult to correct this for borehole effects by using conventional methods because both near and far density measurement is significantly sensitive to standoffs and mud properties. - Highlights: → Monte Carlo evaluation of pulsed neutron gamma-ray density tools. → Results indicate sensitivity of the tool to standoff and mudcake properties. → Accuracy of far spaced detector is better than near spaced.

Computation of porosity and water content from geophysical logs, Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Nelson, P.H.

1996-01-01

Neutron and density logs acquired in boreholes at Yucca Mountain, Nevada are used to determine porosity and water content as a function of depth. Computation of porosity requires an estimate of grain density, which is provided by core data, mineralogical data, or is inferred from rock type where neither core nor mineralogy are available. The porosity estimate is merged with mineralogical data acquired by X-ray diffraction to compute the volumetric fractions of major mineral groups. The resulting depth-based portrayal of bulk rock composition is equivalent to a whole rock analysis of mineralogy and porosity. Water content is computed from epithermal and thermal neutron logs. In the unsaturated zone, the density log is required along with a neutron log. Water content can also be computed from dielectric logs, which were acquired in only a fraction of the boreholes, whereas neutron logs were acquired in all boreholes. Mineralogical data are used to compute a structural (or bound) water estimate, which is subtracted from the total water estimate from the neutron-density combination. Structural water can be subtracted only from intervals where mineralogical analyses are available; otherwise only total water can be reported. The algorithms and procedures are applied to logs acquired during 1979 to 1984 at Yucca Mountain. Examples illustrate the results. Comparison between computed porosity and core measurements shows systematic differences ranging from 0.005 to 0.04. These values are consistent with a sensitivity analysis using uncertainty parameters for good logging conditions. Water content from core measurements is available in only one borehole, yielding a difference between computed and core-based water content of 0.006

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

International Nuclear Information System (INIS)

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

1993-01-01

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 ( 40 K). However, 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

Interpretation of geophysical borehole measurements and petrophysical measurements from KAS02, KAS04, KAS06, KAS07 and KAS08

Energy Technology Data Exchange (ETDEWEB)

Mattsson, Haakan (GeoVista AB (Sweden))

2011-01-15

This report presents the compilation and interpretations of geophysical logging data from the cored boreholes KAS02, KAS04, KAS06, KAS07 and KAS08, and petrophysical measurements on rock samples from the boreholes KAS02, KAS06 and KAS08. The boreholes were drilled and investigated in the 1980's during the construction of the Aspo Hard Rock Laboratory (HLR). The number of logging methods is therefore fewer for these boreholes compared with the data collected during the site investigations at Oskarshamn and Forsmark. The quality control led to that many of the logs had to be length adjusted with reference to the updated rock type mapping. Noise levels are generally low or moderate and the density and magnetic susceptibility logs fit well with data from core samples. The main objective of the investigation was to use the results as supportive information during the geological core mapping and as supportive information during the geological single-hole interpretation. The interpretation shows a general dominance of silicate density in the range 2,720-2,820 kg/m3, and along these sections of the boreholes the natural gamma radiation is c. 10-20 muR/h and the magnetic susceptibility is c. 0.010-0.050 SI. This combination of physical properties most likely corresponds to occurrences of Aespoe diorite. In all five boreholes there are one (or a couple) of fairly long sections, 20-100 m, of significantly increased natural gamma radiation, decreased density and magnetic susceptibility; a combination of physical properties that is typical for fine-grained granite. Along these sections there are generally indications of possible deformation zones and also significant anomalies in the vertical fluid temperature gradient, which indicates that the fine-grained dykes are related to water bearing deformation zones. Significantly increased density in combination with decreased natural gamma radiation commonly occurs along short (< 1 m long) sections in all boreholes, and this

Geophysical log database for the Floridan aquifer system and southeastern Coastal Plain aquifer system in Florida and parts of Georgia, Alabama, and South Carolina

Science.gov (United States)

Williams, Lester J.; Raines, Jessica E.; Lanning, Amanda E.

2013-04-04

A database of borehole geophysical logs and other types of data files were compiled as part of ongoing studies of water availability and assessment of brackish- and saline-water resources. The database contains 4,883 logs from 1,248 wells in Florida, Georgia, Alabama, South Carolina, and from a limited number of offshore wells of the eastern Gulf of Mexico and the Atlantic Ocean. The logs can be accessed through a download directory organized by state and county for onshore wells and in a single directory for the offshore wells. A flat file database is provided that lists the wells, their coordinates, and the file listings.

Repeated temperature logs from Czech, Slovenian and Portuguese borehole climate observatories

Czech Academy of Sciences Publication Activity Database

Šafanda, Jan; Rajver, D.; Correia, A.; Dědeček, Petr

2007-01-01

Roč. 3, č. 3 (2007), s. 453-462 ISSN 1814-9324 R&D Projects: GA AV ČR(CZ) IAA300120603 Grant - others:NATO(US) PDD(CP)-(EST.CLG 980 152) Institutional research plan: CEZ:AV0Z30120515 Source of funding: V - iné verejné zdroje Keywords : borehole temperatures * temperature logs * borehole climate observatories Subject RIV: DC - Siesmology, Volcanology, Earth Structure Impact factor: 1.450, year: 2007

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

Energy Technology Data Exchange (ETDEWEB)

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.

An integrated geophysical and hydraulic investigation to characterize a fractured-rock aquifer, Norwalk, Connecticut

Science.gov (United States)

Lane, J.W.; Williams, J.H.; Johnson, C.D.; Savino, D.M.; Haeni, F.P.

2002-01-01

The U.S. Geological Survey conducted an integrated geophysical and hydraulic investigation at the Norden Systems, Inc. site in Norwalk, Connecticut, where chlorinated solvents have contaminated a fractured-rock aquifer. Borehole, borehole-to-borehole, surface-geophysical, and hydraulic methods were used to characterize the site bedrock lithology and structure, fractures, and transmissive zone hydraulic properties. The geophysical and hydraulic methods included conventional logs, borehole imagery, borehole radar, flowmeter under ambient and stressed hydraulic conditions, and azimuthal square-array direct-current resistivity soundings. Integrated interpretation of geophysical logs at borehole and borehole-to-borehole scales indicates that the bedrock foliation strikes northwest and dips northeast, and strikes north-northeast to northeast and dips both southeast and northwest. Although steeply dipping fractures that cross-cut foliation are observed, most fractures are parallel or sub-parallel to foliation. Steeply dipping reflectors observed in the radar reflection data from three boreholes near the main building delineate a north-northeast trending feature interpreted as a fracture zone. Results of radar tomography conducted close to a suspected contaminant source area indicate that a zone of low electromagnetic (EM) velocity and high EM attenuation is present above 50 ft in depth - the region containing the highest density of fractures. Flowmeter logging was used to estimate hydraulic properties in the boreholes. Thirty-three transmissive fracture zones were identified in 11 of the boreholes. The vertical separation between transmissive zones typically is 10 to 20 ft. Open-hole and discrete-zone transmissivity was estimated from heat-pulse flowmeter data acquired under ambient and stressed conditions. The open-hole transmissivity ranges from 2 to 86 ft2/d. The estimated transmissivity of individual transmissive zones ranges from 0.4 to 68 ft2/d. Drawdown monitoring

Borehole data package for the 100-K area ground water wells, CY 1994

International Nuclear Information System (INIS)

Williams, B.A.

1994-01-01

Borehole, hydrogeologic and geophysical logs, drilling, as-built diagrams, sampling, and well construction information and data for RCRA compliant groundwater monitoring wells installed in CY 1994 at the 100-K Basins

The use of radiometric-logging techniques to determine uranium grade in certain mineralised Karoo boreholes

International Nuclear Information System (INIS)

Corner, B.; De Beer, G.P.

1976-05-01

During the period September-October 1975, 22 mineralised boreholes in nine different Karoo uranium occurrences were logged radiometrically with the aim of determining to what accuracy the actual uranium grade could be predicted from the gamma logs. The true uranium grades of the mineralised zones logged were known from existing chemical analyses. The results showed that the uranium grades could be predicted to an accuracy of better than 10% through the use of gamma-logging equipment calibrated at Pelindaba, provided that the ore was in equilibrium and that little or no thorium was present. Disequilibrium is, however, prevalent in the Karoo, and in the holes logged it occurred by depletion of uranium relative to its gamma-emitting daughter products. Such effects were mostly confined to the zone above the water table, and it is concluded that for Karoo-type occurrences, the high radiometric background levels observed over extended distances in some boreholes were indicative of radon-gas buildup, and hence of disequilibrium. It is further concluded that radiometric borehole logging can largely replace chemical analyses in the determination of uranium grade for ore-reserve calculations, although chemical checks for disequilibrium would always be necessary [af

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

International Nuclear Information System (INIS)

Carlsten, S.; Straahle, A.; Ludvigson, Jan-Erik

2001-10-01

This study presents an attempt to correlate images from borehole-TV (BIPS) and borehole radar with interpreted flow anomalies from Difference Flow Meter logging (DIFF). The measurements were performed in the interval 200-400 m in borehole KLX02 at Laxemar. In total, 59 flow anomalies were interpreted by the DIFF-log in this borehole interval. However, 14 flow anomalies were below the rigorous measurement limit for the actual flow meter and are thus regarded as uncertain. In total, 261 features were primarily interpreted by the BIPS-characterization in the borehole interval 200-400 m but only 12 radar reflectors. The low number of interpreted radar reflectors most likely depends on the low frequency of the antenna used in this case which gave a poor depth resolution. The total number of fractures recorded by the core mapping in this interval was 374 (279 in the rock together with 95 fractures in interpreted crush zones). Prior to the correlation analysis it was necessary to adjust the length scales of the BIPS-measurements relative to the length scale of the Difference Flow logging due to non-linear stretching of logging cables etc to achieve the necessary resolution of the depth scale.This adjustment was done by comparing the distances between clearly identified single features in the BIPS-images with the corresponding distances between clearly identified flow anomalies. The BIPS-measurements consist of 5 independent logging sequences in the studied borehole interval, which resulted in 'jumps' when comparing the non-conform length scales of the different sequences. All of the 59 flow anomalies could be correlated (matched) with BIPS-features with varying degree of certainty. A majority of the correlated BIPS-features was classified as open fractures or fractures with cavities. Most of the flow anomalies below the measurement limit were correlated to veins in the rock. In the correlation between borehole radar reflectors and BIPS-features, the calculated angle and

Controlled drilling technology for HLW management. Directional drilling and mechanics/stress measurements in the borehole

International Nuclear Information System (INIS)

Kiho, Kenzo; Shin, Koichi; Okada, Tetsuji; Obuchi, Yasuyoshi; Sunaga, Takayuki; Hase, Kazunori

2013-01-01

Since 2000, Central Research Institute of Electric Power Industry (CRIEPI) has been conducting the project on controlled drilling and the logging/measurement technologies in its boreholes. Especially borehole pressure meter and bore hole stress measurement apparatus which can apply to the controlled drilling system was developed. The bore hole was drilled to the 1000 m long in order to intersect the Omagari fault located at Horonobe town in Hokkaido and its core recovery was 99.8% as of FY. 2011. Using borehole logging/measurement/survey, the geological, hydrological, geo-mechanical, geophysical and geochemical data were collected and the Omagari fault was characterized. (author)

Geophysical logging for mineral exploration and development

International Nuclear Information System (INIS)

Plouffe, R.D.

1981-01-01

It is possible to retrieve from small-diameter holes geophysical data for qualitative interpretation in exploration and quantitative interpretation in the development of orebodies. The primary objectives in the exploration stage are to identify where, within a hole, economic minerals are, and to help in lithological interpretations. Other aspects, which are more quantitative, are the interpretation of downhole logs for parameters which can be used in surface geophysical methods (i.e. density for gravity surveys, acoustic velocities for seismic surveys, and magnetic susceptibility for airborne and ground magnetic surveys). Recent advances in equipment design, portability and durability have made downhole logging in exploration more inexpensive and reliable. This new equipment is being used to generate very precise quantitative results. This is especially true on uranium development projects. The interpretation of gamma logs for eU 3 O 8 values has finally become precise enough that they have begun to replace chemical values in reserve calculations. Another part of development data is density and equilibrium information, which, with today's technology, is being derived from downhole probing. In the years to come, the trends for many metals are toward neutron activation techniques, or in-situ assaying, and the use of multiple logs for better lithological and physical rock property determinations. (auth)

Analysis of logging data from nuclear borehole tools

International Nuclear Information System (INIS)

Hovgaard, J.; Oelgaard, P.L.

1989-12-01

The processing procedure for logging data from a borehole of the Stenlille project of Dansk Naturgas A/S has been analysed. The tools considered in the analysis were an integral, natural-gamma tool, a neutron porosity tool, a gamma density tool and a caliper tool. It is believed that in most cases the processing procedure used by the logging company in the interpretation of the raw data is fully understood. An exception is the epithermal part of the neutron porosity tool where all data needed for an interpretation were not available. The analysis has shown that some parts of the interpretation procedure may not be consistent with the physical principle of the tools. (author)

Geophysical logging for groundwater investigations in Southern Thailand

Directory of Open Access Journals (Sweden)

Phongpiyah Klinmanee

2012-09-01

Full Text Available In Thailand the Department of Groundwater Resources is drilling to find vital aquifers. Sometimes groundwater formations cannot be identified clearly during drilling; therefore, geophysical logging was applied after drilling and before casing.The tool used here is measuring nine parameters in one run, natural gamma ray, spontaneous potential, single point resistance, normal resistivity (AM 8’’, 16’’, 32’’, and 64’’, mud temperature and resistivity. Cutting was used to support the geophysical interpretations. In many cases the groundwater bearing zones could be clearly identified. The combination of andthe possibility choosing from nine parameters measured provided the necessary data base to identify groundwater bearingzones in different environments. It has been demonstrated that in different wells different tools are favorable than others.Based on the conclusions of this study geophysical logging in groundwater exploration is recommended as a normalstandard technique that should be applied in every new well drilled.

Site investigation - equipment for geological, geophysical, hydrogeological and hydrochemical characterization

International Nuclear Information System (INIS)

Almen, K.E.; Fridh, B.; Johansson, B.E.; Sehlstedt, M.

1986-11-01

The investigations are performed within a site investigation program. In total about 60,000 m of cored 56 mm boreholes have been drilled and investigated at eight study sites. A summarized description of the main investigation methods is included. Instruments for geophysical investigations contains equipment for ground measurements as well as for borehole logging. The Geophysical investigations including the borehole radar measurements, are indirect methods for the geological and hydrogeological characterization of the rock formation. Great effort has been laid on the development of hydrogeological instruments for hydraulic tests and groundwater head measurements. In order to obtain hydrochemical investigations with high quality, a complete system for sampling and analysis of ground water has been developed. (orig./PW)

Radiation borehole logging method

International Nuclear Information System (INIS)

Wylie, A.; Mathew, P.J.

1977-01-01

A method of obtaining an indication of the diameter of a borehole is described. The method comprises subjecting the walls of the borehole to monoenergetic gamma radiation and making measurements of the intensity of gamma radiation backscattered from the walls. The energy of the radiation is sufficiently high for the shape to be substantially independent of the density and composition of the borehole walls

Basalt features observed in outcrops, cores, borehole video imagery and geophysical logs, and basalt hydrogeologic study at the Idaho National Engineering Laboratory, Eastern Idaho

International Nuclear Information System (INIS)

Bennecke, W.M.

1996-10-01

A study was undertaken to examine permeable zones identified in boreholes open to the underlying basalt and to describe the vertical cross flows present in the boreholes. To understand the permeable zones in the boreholes detailed descriptions and measurements of three outcrops in the Snake River Plain, three cores at the Idaho Chemical Processing Plant (ICPP) at the INEL, and over fifty borehole TV logs from the INEL were carried out. Based on the observations made on the three outcrops an idealized basalt lava flow model was generated that used a set of nomenclature that would be standard for the basalt lava flows studied. An upper vesicular zone, a sometimes absent columnar zone, central zone, and lower vesicular zone make up the basalt lava flow model. The overall distinction between the different zones are based on the vesicle shape size, vesicularity, and fractures present. The results of the studies also indicated that the basalt lava flows at the INEL are distal to medial facies pahoehoe lava flows with close fitting contacts. The most permeable zones identified in these basalts are fractured vesiculated portions of the top of the lava flow, the columnar areas, and basalt-flow contacts in order of importance. This was determined from impeller flowmeter logging at the INEL. Having this information a detailed stratigraphy of individual basalt lava flows and the corresponding permeable units were generated. From this it was concluded that groundwater flow at the ICPP prefers to travel along thin basalt lava flows or flow-units. Flow direction and velocity of intrawell flows detected by flowmeter is controlled by a nearby pumping well

Method and apparatus for logging a borehole employing dual radiation detectors

International Nuclear Information System (INIS)

Arnold, D.M.

1986-01-01

An apparatus is described for logging a characteristic of a borehole in an earth formation employing nuclear count rate data selectively compensated for non-standard borehole conditions, comprising: a sonde, movable in a borehole, having: a radiation source for emitting radiation into earth formations adjacent the wellbore; first detector, spaced longitudinally from the radiation source, for detecting radiation scattered back to the detector and generating a first signal representative of a first count rate value, C/sub SS/; and second detector spaced a different longitudinal distance from the radiation source, for detecting radiation scattered back to the detector and generating a second signal representative of a count rate value, C/sub LS/; memory means for storing a predetermined threshold value, first predetermined relationships between the borehole characteristic and count rate values C/sub LS/, C/sub SS/; and second predetermined relationships between the borehole characteristic and ratios of C/sub LS/ to C/sub SS/; electronic means for producing a signal related in value to the borehole characteristic, which electronic means compares at least one of the first and second count rate value signals with the predetermined threshold value; means for recording the signal generated by the electronic means

Focused modelling. Fracture identification in Olkiluoto borehole OL-KR04

International Nuclear Information System (INIS)

Jokinen, J.; Jakobsson, K.

2004-10-01

An extensive set of measured borehole data has been obtained from geological repository investigations in the bedrock of Olkiluoto. Our hypothesis is that geophysical data may be used more efficiently to identify and classify fracture zones. It is known that several geophysical logging methods yield useful information outside the borehole walls that cannot be reached otherwise. At present, this data is used for additional fracture characterization but not for identification purposes. The study focuses on the application of 14 different geophysical data measured in the borehole OL-KR04. The whole data set is divided into main groups using the Principal Component Analysis (PCA). Each group is composed mainly of sensitive methods detecting specific physical characteristics. The main groups from the geophysical point of view are open fractures, reduced density, increased electrical conductivity, and increased natural radiation. The Varimax optimization method is used to maximize the importance of supporting data as well as to emphasize differences between the discovered principal components. In fracture zone analysis, drilling core samples and the hydrological measurement results form an indispensable data set. For practical reasons, and in order to fulfill the requirements of the PCA analysis, S-wave velocity and electrical resistivity measurements are also performed. A combination of these methods, simultaneously applied using suitable 'trigger limits', identifies penetrated extensive fracture sections in a borehole cost-effectively and unambiguously. (orig.)

Code of practice for the use of sealed radioactive sources in borehole logging (1998)

International Nuclear Information System (INIS)

1989-12-01

The purpose of this code is to establish working practices, procedures and protective measures which will aid in keeping doses, arising from the use of borehole logging equipment containing sealed radioactive sources, to as low as reasonably achievable and to ensure that the dose-equivalent limits specified in the National Health and Medical Research Council s radiation protection standards, are not exceeded. This code applies to all situations and practices where a sealed radioactive source or sources are used through wireline logging for investigating the physical properties of the geological sequence, or any fluids contained in the geological sequence, or the properties of the borehole itself, whether casing, mudcake or borehole fluids. The radiation protection standards specify dose-equivalent limits for two categories: radiation workers and members of the public. 3 refs., tabs., ills

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

Energy Technology Data Exchange (ETDEWEB)

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

2001-10-01

This study presents an attempt to correlate images from borehole-TV (BIPS) and borehole radar with interpreted flow anomalies from Difference Flow Meter logging (DIFF). The measurements were performed in the interval 200-400 m in borehole KLX02 at Laxemar. In total, 59 flow anomalies were interpreted by the DIFF-log in this borehole interval. However, 14 flow anomalies were below the rigorous measurement limit for the actual flow meter and are thus regarded as uncertain. In total, 261 features were primarily interpreted by the BIPS-characterization in the borehole interval 200-400 m but only 12 radar reflectors. The low number of interpreted radar reflectors most likely depends on the low frequency of the antenna used in this case which gave a poor depth resolution. The total number of fractures recorded by the core mapping in this interval was 374 (279 in the rock together with 95 fractures in interpreted crush zones). Prior to the correlation analysis it was necessary to adjust the length scales of the BIPS-measurements relative to the length scale of the Difference Flow logging due to non-linear stretching of logging cables etc to achieve the necessary resolution of the depth scale.This adjustment was done by comparing the distances between clearly identified single features in the BIPS-images with the corresponding distances between clearly identified flow anomalies. The BIPS-measurements consist of 5 independent logging sequences in the studied borehole interval, which resulted in 'jumps' when comparing the non-conform length scales of the different sequences. All of the 59 flow anomalies could be correlated (matched) with BIPS-features with varying degree of certainty. A majority of the correlated BIPS-features was classified as open fractures or fractures with cavities. Most of the flow anomalies below the measurement limit were correlated to veins in the rock. In the correlation between borehole radar reflectors and BIPS-features, the calculated

FLOZ-the computer program for the primary interpretation of nuclear borehole logging

International Nuclear Information System (INIS)

Zorski, T.

1979-01-01

This work presents the FLOZ program for nuclear well logging data interpretation. Program has been written in FORTRAN 1900 language for ODRA 1300 computers. The description of the program possibilities and the ways of its application are given. Short presentation of the interpretation method used here and the description of the program work with its complete listing, together with the explanatory commentaries are also presented. The type of interpretation performed by the program depends upon the kind of nuclear logging of interest. For neutron-gamma and gamma-gamma logging the program introduces the corrections for the following disturbing factors: the ratemeter time constant, the logging speed, the apparatus dead time, the gamma-ray background. The gamma-ray logging is corrected for the following disturbing factors: ratemeter time constant, the logging speed, the apparatus dead time of tool, borehole radius, gamma-ray absorbtion in the borehole liquid and the finite thickness of the layers. The calibration constant for gamma-ray probe can be introduced for calculations of radioactivity ore grades. The log deflections being the input data for the FLOZ program, are taken from specially prepared magnetic tape. The results of interpretation are written on magnetic tape, according to the X3GY system for the ODRA 1300 computers. The method of interpretation which is applicated in program FLOZ was elaborated by Prof. J.A. Czubek from Institute of Nuclear Physics in Cracow. (author)

Comparing plume characteristics inferred from cross-borehole geophysical data

DEFF Research Database (Denmark)

Haarder, Eline Bojsen; Binley, Andrew; Zibar, Majken Caroline Looms

2012-01-01

significantly influences results of the moment analysis. We compare results of three cross-borehole geophysical approaches for imaging tracer migration arising from a point injection of water in the unsaturated zone: three-dimensional electrical resistivity tomography (ERT), two-dimensional ground......-penetrating radar (GPR) tomography and quasi-three-dimensional GPR tomography. In the studied field experiment, a tracer was injected for a period of 5 d and was monitored both during injection and for 5 d during the subsequent redistribution. The three methods show similar characteristics of the plume development...

Analysis of geophysical well logs from the Mariano Lake-Lake Valley drilling project, San Juan Basin, Northwestern New Mexico

International Nuclear Information System (INIS)

Scott, J.H.

1986-01-01

Geophysical well logs were obtained in eight deep holes drilled and cored by the U.S. Geological Survey to examine the geology of the Mariano Lake-Lake Valley area in the southern part of the San Juan basin, New Mexico. The logs were made to determine the petrophysical properties of the rocks penetrated by the holes, to aid in making stratigraphic correlations between the holes, and to estimate the grade of uranium enrichment in mineralized zones. The logs can be divided into six categories-nuclear, electric, sonic, magnetic, dipmeter, and borehole conditions. Examples of these logs are presented and related to lithological and petrophysical properties of the cores recovered. Gamma-ray and prompt fission neutron logs were used to estimate uranium grade in mineralized zones. Resistivity and spontaneous potential logs were used to make stratigraphic correlations between drill holes and to determine the variability of the sandstone:mudstone ratios of the major sedimentary units. In one drill hole a dipmeter log was used to estimate the direction of sediment transport of the fluvial host rock. Magnetic susceptibility logs provided supportive information for a laboratory study of magnetic mineral alteration in drill cores. This study was used to infer the geochemical and hydrologic environment associated with uranium deposition in the project area

Effect of radon transport in groundwater upon gamma-ray borehole logs

International Nuclear Information System (INIS)

Nelson, P.H.; Rachiele, R.; Smith, A.

1980-09-01

Granitic rock at an experimental waste storage site at Stripa, Sweden, is unusually high in natural radioelements (40 ppM uranium) with higher concentrations occurring locally in thin chloritic zones and fractures. Groundwater seeping through fractures into open boreholes is consequently highly anomalous in its radon content, with activity as high as one microcurie per liter. When total count gamma-ray logs are run in boreholes where groundwater inflow is appreciable, the result is quite unusual: the radon daughter activity in the water adds considerably to the contribution from the rock, and in fact often dominates the log response. The total gamma activity increases where radon-charged groundwater enters a borehole, and remains at a high level as the water flows along the hole in response to the hydraulic gradient. As a consequence, the gamma log serves as a flow profile, locating zones of water entry (or loss) by an increase (or decrease) in the total gamma activity. A simple model has been developed for flow through a thin crack emanating radon at a rate E showing that the radon concentration of water entering a hole is E/Λh, where Λ is the radon decay rate and h the crack aperture, assuming that the flow rate and crack source area are such that an element of water resides within the source area for several radon half-lives or more. Concentration measurements can provide a measurement of the inflow rate. Data from the 127-mm holes in the time-scale drift behave in this fashion

Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, August 1993 to February 1994

Energy Technology Data Exchange (ETDEWEB)

Geslin, J.K.; Moyer, T.C.; Buesch, D.C.

1995-05-01

Yucca Mountain, Nevada, is being investigated as a potential site for a high-level radioactive waste repository. This report summarizes the lithologic logging of new and existing boreholes at Yucca Mountain that was done from August 1993 to February 1994 by the Rock Characteristics Section, Yucca Mountain Project Branch, US Geological Survey (USGS). Units encountered during logging include Quaternary-Tertiary alluvium/colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, Tertiary Calico Hills Formation and Tertiary Prow Pass Tuff. We present criteria used for recognition of stratigraphic contacts, logging results as tables of contact depths for core from neutron (UZN) boreholes and graphical lithologic logs for core from non-UZN boreholes, and descriptions of several distinctive nonwelded tuffs recognized in the PTn hydrogeologic unit of the Paintbrush Group.

Summary of lithologic logging of new and existing boreholes at Yucca Mountain, Nevada, August 1993 to February 1994

International Nuclear Information System (INIS)

Geslin, J.K.; Moyer, T.C.; Buesch, D.C.

1995-01-01

Yucca Mountain, Nevada, is being investigated as a potential site for a high-level radioactive waste repository. This report summarizes the lithologic logging of new and existing boreholes at Yucca Mountain that was done from August 1993 to February 1994 by the Rock Characteristics Section, Yucca Mountain Project Branch, US Geological Survey (USGS). Units encountered during logging include Quaternary-Tertiary alluvium/colluvium, Tertiary Rainier Mesa Tuff, all units in the Tertiary Paintbrush Group, Tertiary Calico Hills Formation and Tertiary Prow Pass Tuff. We present criteria used for recognition of stratigraphic contacts, logging results as tables of contact depths for core from neutron (UZN) boreholes and graphical lithologic logs for core from non-UZN boreholes, and descriptions of several distinctive nonwelded tuffs recognized in the PTn hydrogeologic unit of the Paintbrush Group

A portable borehole temperature logging system using the four-wire resistance method

Science.gov (United States)

Erkan, Kamil; Akkoyunlu, Bülent; Balkan, Elif; Tayanç, Mete

2017-12-01

High-quality temperature-depth information from boreholes with a depth of 100 m or more is used in geothermal studies and in studies of climate change. Electrical wireline tools with thermistor sensors are capable of measuring borehole temperatures with millikelvin resolution. The use of a surface readout mode allows analysis of the thermally conductive state of a borehole, which is especially important for climatic and regional heat flow studies. In this study we describe the design of a portable temperature logging tool that uses the four-wire resistance measurement method. The four-wire method enables the elimination of cable resistance effects, thus allowing millikelvin resolution of temperature data at depth. A preliminary two-wire model of the system is also described. The portability of the tool enables one to collect data from boreholes down to 300 m, even in locations with limited accessibility.

Geophysical investigations in the Veitsivaara area, Finland summary report

International Nuclear Information System (INIS)

Heikkinen, E.; Saksa, P.; Hinkkanen, H.

1991-10-01

Teollisuuden Voima Oy (TVO carries out site investigations in Finland for final disposal of nuclear high level waste during 1987-2000. Investigations by geological, geophysical, geohydrological and geochemical methods were carried out in the Veitsivaara area in 1987-90 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. Airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity. Airborne surveys were performed by magnetic, radiometric and two electromagnetic methods and ground investigations by VLF magnetic and resistivity, magnetic and impulse radar methods. Electromagnetic and seismic refraction surveys were used to locate crushed and fracture zones. The properties of weak electrical conductors, e.g. their depth dimensions, were studied by direct current resistivity measurements. The rock type distribution was studied by single-hole logging of susceptibility, natural γ-radiation and radiometric γ γ-density. Electrical and acoustic logging allowed water bearing fractures to be mapped and the results of water injection tests to be interpreted. Flow conditions in the boreholes were studied by both fluid logging and tube wave sounding

Fault fracture zone evaluation using borehole geophysical logs; case study at Nojima fault, Awaji island; Kosei butsuri kenso ni yoru danso hasaitai no hyoka

Energy Technology Data Exchange (ETDEWEB)

Ikeda, R; Omura, K [National Research Institute for Disaster Prevention, Tsukuba (Japan); Yamamoto, T [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)

1997-10-22

Ikeda, et al., in their examination of log data obtained from a borehole (2000m deep) drilled at Ashio, Tochigi Prefecture, where micro-earthquakes swarm at very shallow levels, pay special attention to porosity. Using correlationship between the porosity and elastic wave velocity/resistivity, the authors endeavor to find the presence of secondary pores, dimensions of faults, composition of water in strata in faults, and difference in matrix between rocks, all these for the classification and evaluation of fault fracture zones. In the present report, log data from a borehole (1800m deep) drilled to penetrate the Nojima fault (Nojima-Hirabayashi, Awaji island) that emerged during the Great Hanshin-Himeji Earthquake are analyzed in the same way as the above-named Ashio data, and the results are compared with the Ashio results. Immediately below the Nojima-Hirabayashi fault fractured zone, stress is found remarkably reduced and the difference stress quite small in size. This is interpreted as indicating a state in which clay has already developed well in the fault fractured zone ready to allow the occurrence of shear fracture or a state in which such has already occurred for the release of stress. 4 refs., 5 figs.

Circular induction accelerator for borehole logging

International Nuclear Information System (INIS)

Chen, F.K.; Bertozzi, W.; Corris, G.W.; Diamond, W.; Doucet, J.A.; Schweitzer, J.S.

1992-01-01

This patent describes a downhole logging sonde adapted to be moved through a borehole, a source of gamma rays in the sonde for irradiating earth formations traversed by the borehole, one or more gamma ray detectors for detecting gamma rays scattered back to the sonde from the irradiated earth formations, and means for transmitting signals representative of the detected gamma rays to the earth's surface for processing. This patent describes improvement in the gamma ray source comprises a magnetic induction particle accelerator, including: a magnetic circuit having a field magnet, generally circular opposed pole pieces, and a core magnet metal ions from the group consisting of Mn, Zn and Ni; an excitation circuit including a field coil surrounding the field magnet and the core magnet and a core coil surrounding the central axially leg of the core magnet; an annular acceleration chamber interposed between the pole pieces; means for applying time-varying acceleration voltage pulses across the primary excitation circuit; means for injecting charged particles into orbit within the acceleration chamber; means for compressing the particle orbits to trap particles within generally circular orbits within the acceleration chamber; means for generating a particle accelerating magnetic flux in the magnetic circuit; and means for ejecting charged particles from the generally circular orbits and into contact with a target to produce gamma ray photons

Rapid estimation of aquifer salinity structure from oil and gas geophysical logs

Science.gov (United States)

Shimabukuro, D.; Stephens, M.; Ducart, A.; Skinner, S. M.

2016-12-01

We describe a workflow for creating aquifer salinity maps using Archie's equation for areas that have geophysical data from oil and gas wells. We apply this method in California, where geophysical logs are available in raster format from the Division of Oil, Gas, and Geothermal Resource (DOGGR) online archive. This method should be applicable to any region where geophysical logs are readily available. Much of the work is controlled by computer code, allowing salinity estimates for new areas to be rapidly generated. For a region of interest, the DOGGR online database is scraped for wells that were logged with multi-tool suites, such as the Platform Express or Triple Combination Logging Tools. Then, well construction metadata, such as measured depth, spud date, and well orientation, is attached. The resultant local database allows a weighted criteria selection of wells that are most likely to have the shallow resistivity, deep resistivity, and density porosity measurements necessary to calculate salinity over the longest depth interval. The algorithm can be adjusted for geophysical log availability for older well fields and density of sampling. Once priority wells are identified, a student researcher team uses Neuralog software to digitize the raster geophysical logs. Total dissolved solid (TDS) concentration is then calculated in clean, wet sand intervals using the resistivity-porosity method, a modified form of Archie's equation. These sand intervals are automatically selected using a combination of spontaneous potential and the difference in shallow resistivity and deep resistivity measurements. Gamma ray logs are not used because arkosic sands common in California make it difficult to distinguish sand and shale. Computer calculation allows easy adjustment of Archie's parameters. The result is a semi-continuous TDS profile for the wells of interest. These profiles are combined and contoured using standard 3-d visualization software to yield preliminary salinity

Neutron activation for logging the distribution of gold in bore-hole cores

International Nuclear Information System (INIS)

Rahmanian, H.; Watterson, J.I.W.

1992-01-01

A new method for the non-destructive determination of gold in bore-hole cores has been developed using instrumental neutron activation analysis with a 252 Cf source. The procedure obtains the distribution and concentration of gold along the longitudinal axis of the core i.e. a log of the gold concentration. The accuracy of the method is comparable to fire assay at a level of 2 ppm and has a detection limit of 1 ppm under the conditions used. The assay of the gold is carried out by employing a novel variation of the conventional comparator method using gold wires as both standard and flux monitor. A method is described for logging gold in bore-hole cores using neutron activation with a 160 μg 252 Cf neutron source. The method has a limit of detection of about 1 ppm under the described conditions. (author)

Correlation between rotary drill performance parameters and borehole geophysical logging

International Nuclear Information System (INIS)

Scoble, M.J.; Peck, J.; Hendricks, C.

1989-01-01

There is a growing interest in developing performance monitoring techniques for both surface and underground mining equipment used in excavating, loading and transport systems. Research into the techniques and applications for monitoring drilling machinery including gamma and neutron logging, is reviewed. 17 refs.; 5 figs

Simulations of a spectral gamma-ray logging tool response to a surface source distribution on the borehole wall

International Nuclear Information System (INIS)

Wilson, R.D.; Conaway, J.G.

1991-01-01

We have developed Monte Carlo and discrete ordinates simulation models for the large-detector spectral gamma-ray (SGR) logging tool in use at the Nevada Test Site. Application of the simulation models produced spectra for source layers on the borehole wall, either from potassium-bearing mudcakes or from plate-out of radon daughter products. Simulations show that the shape and magnitude of gamma-ray spectra from sources distributed on the borehole wall depend on radial position with in the air-filled borehole as well as on hole diameter. No such dependence is observed for sources uniformly distributed in the formation. In addition, sources on the borehole wall produce anisotropic angular fluxes at the higher scattered energies and at the source energy. These differences in borehole effects and in angular flux are important to the process of correcting SGR logs for the presence of potassium mudcakes; they also suggest a technique for distinguishing between spectral contributions from formation sources and sources on the borehole wall. These results imply the existence of a standoff effect not present for spectra measured in air-filled boreholes from formation sources. 5 refs., 11 figs

Detection of unexploded ordnance by PGNAA based borehole-logging

International Nuclear Information System (INIS)

John Kettler; RWTH-Aachen University, Aachen; Eric Mauerhofer; Marco Steinbusch

2013-01-01

The performance of a borehole-logging system, based on prompt-gamma-neutron-activation-analysis (PGNAA), for explosive detection was studied by Monte-Carlo simulations. The prompt gamma of nitrogen, which is a constituent of common explosive, was used to identify the unexploded ordnance (UXO). Our results show that the minimum counting time depends on the soil moisture, the cladding thickness and the explosive composition. In conjunction with the standard detection by magnetometry, the PGNAA is a promising analytical technique for definitive identification of deep buried UXOs. (author)

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

International Nuclear Information System (INIS)

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

2013-01-01

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)

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

Energy Technology Data Exchange (ETDEWEB)

McCain, R.G.; Henwood, P.D.; Pope, A.D.; Pearson, A.W. [S M Stoller Corporation, 2439 Robertson Drive, Richland, WA 99354 (United States)

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)

Study on structural plane characteristics of deep rock mass based on acoustic borehole TV

International Nuclear Information System (INIS)

Wang Xiyong; Su Rui; Chen Liang; Tian Xiao

2014-01-01

Deep rock mass structural plane characteristics are one of the basic data for evaluating the quality of rock mass. Based on acoustic borehole TV, the structural plane quantity, density, attitude, dominant set, structural plane aperture of deep rock mass in boreholes BS15 # and BS16 # located in Beishan granite rock mass of Gansu Province have been calculated and compared with the results of geological documentation of drill core. The results indicate that acoustic borehole TV has the effect in study on characteristics of structural plane. But as a kind of technique of geophysical logging, the acoustic borehole TV has certain defect, and need to combine with the analysis of the other geological materials in applications. (authors)

Exploratory borehole Leuggern. Working program

International Nuclear Information System (INIS)

1984-07-01

An extensive geophysical borehole logging programme will serve to verify the results of the core analysis and complement the core data. Numerous borehole logs are to be registered with different types of tools. These allow one to determine various parameters essential for the full description of the rock sequences penetrated. A first category of logs enables the petrographical identification of the different rock types and indicates porous zones that are either water- or hydrocarbon-bearing. A second category provides data e.g. on the degree of pore and fracture fill, rock density and rock temperature, natural gamma radiation and rock-mechanical properties. Other logs measure strike and dip of the sedimentary layers and the position of rock fractures. A fourth category provides information on the diameter and the deviation of the borehole, the quality of casing cementations and the position of casing joints. In addition, well shooting surveys will supply exact values of seismic velocities for the various rock units; data that are needed for the depth correction of the reflection profiles from Nagra's regional seismic network. With numerous hydrological tests ranging from a production tests of the Muschelkalk and Buntsandstein aquifers to labelled slug-tests in low-permeability crystalline sections, the hydraulic conditions of deep groundwater flow will be investigated. The recovered water samples will undergo full physical and geochemical analysis. Furthermore, their isotope content is to be measured in order to estimate the age of the various formation waters and their time of residence in the subsurface. To round off the scientific investigations, a series of rock-mechanical and geotechnical laboratory tests will provide characteristic values to be applied eventually in the design and construction of shafts and caverns for an underground repository

Simulation of density curve for slim borehole using the Monte Carlo code MCNPX

International Nuclear Information System (INIS)

Souza, Edmilson Monteiro de; Silva, Ademir Xavier da; Lopes, Ricardo Tadeu; Lima, Inaya C.B.; Rocha, Paula L.F.

2010-01-01

Borehole logging for formation density has been an important geophysical measurement in oil industry. For calibration of the Gamma Ray nuclear logging tool, numerous rock models of different lithology and densities are necessary. However, the full success of this calibration process is determined by a reliable benchmark, where the complete and precise chemical composition of the standards is necessary. Simulations using the Monte Carlo MCNP have been widely employed in well logging application once it serves as a low-cost substitute for experimental test pits, as well as a means for obtaining data that are difficult to obtain experimentally. Considering this, the purpose of this work is to use the code MCNP to obtain density curves for slim boreholes using Gamma Ray logging tools. For this, a Slim Density Gamma Probe, named TRISOND R , and a 100 mCi Cs-137 gamma source has been modeled with the new version of MCNP code MCNPX. (author)

Simulation of density curve for slim borehole using the Monte Carlo code MCNPX

Energy Technology Data Exchange (ETDEWEB)

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

2010-07-01

Borehole logging for formation density has been an important geophysical measurement in oil industry. For calibration of the Gamma Ray nuclear logging tool, numerous rock models of different lithology and densities are necessary. However, the full success of this calibration process is determined by a reliable benchmark, where the complete and precise chemical composition of the standards is necessary. Simulations using the Monte Carlo MCNP have been widely employed in well logging application once it serves as a low-cost substitute for experimental test pits, as well as a means for obtaining data that are difficult to obtain experimentally. Considering this, the purpose of this work is to use the code MCNP to obtain density curves for slim boreholes using Gamma Ray logging tools. For this, a Slim Density Gamma Probe, named TRISOND{sup R}, and a 100 mCi Cs-137 gamma source has been modeled with the new version of MCNP code MCNPX. (author)

Geophysical constraints on Rio Grande rift structure and stratigraphy from magnetotelluric models and borehole resistivity logs, northern New Mexico

Science.gov (United States)

Rodriguez, Brian D.; Sawyer, David A.; Hudson, Mark R.; Grauch, V.J.S.

2013-01-01

Two- and three-dimensional electrical resistivity models derived from the magnetotelluric method were interpreted to provide more accurate hydrogeologic parameters for the Albuquerque and Española Basins. Analysis and interpretation of the resistivity models are aided by regional borehole resistivity data. Examination of the magnetotelluric response of hypothetical stratigraphic cases using resistivity characterizations from the borehole data elucidates two scenarios where the magnetotelluric method provides the strongest constraints. In the first scenario, the magnetotelluric method constrains the thickness of extensive volcanic cover, the underlying thickness of coarser-grained facies of buried Santa Fe Group sediments, and the depth to Precambrian basement or overlying Pennsylvanian limestones. In the second scenario, in the absence of volcanic cover, the magnetotelluric method constrains the thickness of coarser-grained facies of buried Santa Fe Group sediments and the depth to Precambrian basement or overlying Pennsylvanian limestones. Magnetotelluric surveys provide additional constraints on the relative positions of basement rocks and the thicknesses of Paleozoic, Mesozoic, and Tertiary sedimentary rocks in the region of the Albuquerque and Española Basins. The northern extent of a basement high beneath the Cerros del Rio volcanic field is delineated. Our results also reveal that the largest offset of the Hubbell Spring fault zone is located 5 km west of the exposed scarp. By correlating our resistivity models with surface geology and the deeper stratigraphic horizons using deep well log data, we are able to identify which of the resistivity variations in the upper 2 km belong to the upper Santa Fe Group sediment

Description of geophysical data in the SKB database GEOTAB

International Nuclear Information System (INIS)

Sehlstedt, S.

1988-02-01

For the storage of different types of data collected by SKB a database called Geotab has been created. The following data are stored in the database: Background data, geological data, geophysical data, hydrogeological data, hydrochemical data. This report describes the data flow for different types of geophysical measurements. The descriptions start with measurements and end with the storage of data in Geotab. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, profile measurements; geophysical ground surface measurements, grid net measurements; geophysical borehole logging; petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in Geotab. (orig.)

INGDB-90. The International Neutron Nuclear Data Base for geophysics applications

International Nuclear Information System (INIS)

Kocherov, N.P.; McLaughline, P.K.

1991-01-01

This document describes the contents of the International Neutron Nuclear Data Base for applications in nuclear geophysics, such as borehole logging and mineral analysis. It contains neutron cross-section data from 19 elements and their isotopes of primary importance in geophysics, plus a data file with neutron spectra of three frequently used neutron sources. The INGDB-90 file is available, cost free, from the IAEA Nuclear Data Section on PC diskettes or on magnetic tape. (author). 9 refs

Optimal geophysical complex and methods for investigation of peleogene and upper cretaceous deposits in search and exploratory wells in the northern areas of Tumen region

International Nuclear Information System (INIS)

Nelepchenko, O.M.; Akhiyarov, V.Kh.

1975-01-01

A number of geophysical studies of the Paleogene and upper Cretaceous deposits in prospecting and exploration boreholes in the northern part of the Tyumen field are described. The studies include, besides the essential ones, neutron logging with thermal neutrons (NKT-50), infrared logging, and lateral logging

Current trends in nuclear borehole logging techniques for elemental analysis

International Nuclear Information System (INIS)

1988-06-01

This report is the result of a consultants' meeting organized by the IAEA and held in Ottawa, Canada, 2-6 November 1987 in order to assess the present technical status of nuclear borehole logging techniques, to find out the well established applications and the development trends. It contains a summary report giving a comprehensive overview of the techniques and applications and a collection of research papers describing work done in industrial institutes. A separate abstract was prepared for each of these 9 papers. Refs, figs and tabs

Fracture mapping in rock slope using geophysical instruments; Butsuri tansa ni yoru ganban shamennai no kiretsu bunpu hyoka

Energy Technology Data Exchange (ETDEWEB)

Kurahashi, T; Inazaki, T [Public Works Research Institute, Tsukuba (Japan); Watanabe, S [Geological Survey of Japan, Tsukuba (Japan)

1997-05-27

An attempt was made to visualize distribution of cracks in a rock slope by applying geophysical survey onto a rock slope. Geophysical logging and seismic survey using the reflection method were used as the methods for the geophysical survey. The rock slope subjected to the survey is located in a gorge along the Yoshino river in Yamashiro Town, Tokushima Prefecture. The slope has a width of 25 m and a height of 30 m. Its overhang in a nose form may has a possibility of causing collapse due to sliding. Cracks developed by horizontal schistosity were detected by performing geophysical logging on VSP, calipers, natural gamma-ray spectra, temperature and borehole in a borehole drilled vertically from the top of the slope. The seismic survey using the reflection method detected the cracks by emphasizing joints in the perpendicular direction. A possibility was shown to visualize the crack distribution with high resolution by using the above geophysical survey on the rock slope. In order to detect the crack distribution with still higher resolution, development into a three-dimensional exploration in the future is desired, not to speak of improvement in signal receivers, and discussions on geometry. 1 ref., 6 figs.

Borehole Data Package for Calendar Year 2000-2001 RCRA Wells at Single-Shell Tank Waste Management Area T

International Nuclear Information System (INIS)

Horton, Duane G; Hodges, Floyd N

2001-01-01

This document compiles information of the drilling and construction, well development, pump installation, and sediment and groundwater sampling applicable to the installation of five new RCRA wells in calendar year 2000 - 2001. Appendix A contains the Well Summary Sheets (as-built diagrams); the Well Construction Summary Reports, and the geologist's logs; Appendix B contains physical properties data; and Appendix C contains the borehole geophysical logs

Well logging. Acquisition and applications; Diagraphies. Acquisition et applications

Energy Technology Data Exchange (ETDEWEB)

Serra, O.; Serra, L.

2001-07-01

This reference book on wire-line and LWD well logging covers all geophysical methods of underground survey in a synthetic, visual and dynamical way. It treats of: the physical principle of well logging measurements, the different types of existing probes, the factors that can influence the measurements, and the applications of these measurements. The following well-logging methods are reviewed: resistivity; electromagnetic wave propagation; magnetic susceptibility and magnetic field; spontaneous potential; nuclear logging: natural gamma radioactivity, density logging, photoelectric index, neutron emission probes, hydrogen index or neutron porosity, neutron induced gamma spectroscopy, neutron relaxation time, NMR; acoustic measurements: sonic logging, seismic profiles; texture, structure and stratigraphy data acquisition; borehole diameter measurement; temperature measurement; wire sampling methods; place and role of well-logging in petroleum exploration; well-logging programs. (J.S.)

Identification of carbonate reservoirs based on well logging data for boreholes drilled using oil base muds

International Nuclear Information System (INIS)

Abdukhalikov, Ya.N; Serebrennikov, V.S.

1979-01-01

Experiment on carbonate reservoir identification according to well logging data for boreholes drilled using oil base muds is described. Pulse neutron-neutron logging (PNNL) was widely used at the territory of Pripyat' hole to solve the task. To evaluate volumetric clayiness of carbonate rocks the dependence of gamma-logging, that is data of gamma-logging against clayey rocks built for every hollow, is used. Quantitative estimation of clayiness of dense and clayey carbonate rocks-non-reservoirs is carried out on the basis of the data of neutron-gamma and acoustic logging. Porosity coefficient and lithological characteristic of rocks are also determined according to the data of acoustic and neutron gamma-logging

Porosity measurements of crystalline rocks by laboratory and geophysical methods

International Nuclear Information System (INIS)

Alexander, J.; Hall, D.H.; Storey, B.C.

1981-12-01

Porosity values of igneous and metamorphic crystalline rocks have been determined from core samples taken at specific depths from Altnabreac, by a combination of laboratory and geophysical techniques. Using resaturation and mercury injection methods in three laboratories within I.G.S., porosity values have been derived and the effect of variations in the measuring techniques and results obtained have been compared. Comparison of inter-laboratory porosity values illustrates that systematic errors are present, resulting in higher porosity values for samples subjected to re-testing. This is considered to be caused by the variable nature of the initial samples combined with the inability to completely dry or resaturate samples during a second testing. Geophysical techniques for determining in situ porosity using the neutron log have been carried out in borehole ALA. The neutron log has been calibrated with laboratory derived porosity values and an empirical formula derived enabling porosity values to be ascribed throughout the logged borehole ALA. Comparison of the porosity results from Altnabreac with crystalline samples elsewhere in America, Europe and the U.K. suggest that porosities at Altnabreac are lower than average. However, very few publications concerned with water movement in crystalline areas actually state the method used. (author)

Well logging instrumental and methodological research

International Nuclear Information System (INIS)

Andrassy, L.; Barath, I.; Dorko, R.

1983-01-01

This part of the Annual Report of the Roland Eoetvoes Geophysical Institute (ELGI) of Hungary for 1982, summarizes the well logging instrumental and methodological researches of ELGI. The theoretical neutron diffusion fluxes for black and brown coals of Hungarian mines were calculated. A coal probe was developed and tested in boreholes using computerized data processing and interpretation. An X-ray radiometric method was used for the determination of Cu and Fe contents of minerals. Researches in the field of magnetic susceptibility and induced polarization logging are also summarized. A rapid analyzer for bauxite mining and a photorecorder for petroleum industry were developed by ELGI. (D.Gy.)

The application of geophysical logging at in-situ leaching uranium mine in China

International Nuclear Information System (INIS)

Liu Zeyao; Xu Shusheng; Li Zhongqiu

1999-01-01

The status of work, instrument and method employed for geophysical logging in different stages at in-situ leaching uranium mine are discussed and the development of software, electrical current logging and gamma ray logging are presented based on the requirement of in-situ leaching of uranium. In addition, new function and method with regard to home instrument are proposed for future work

Fingerprints of zones in boreholes. An approach to identify the characteristics of structures

Energy Technology Data Exchange (ETDEWEB)

Straeng, Thomas; Waenstedt, Stefan; Tiren, Sven (GEOSIGMA AB (Sweden))

2010-11-15

The classification of geophysical borehole data in order to identify and characterize structures, which intercepts the borehole, is an important part of 3D modelling of the structural pattern of the bedrock. The objective of this study is to test a statistical approach, cluster analysis, on site data in order to see if it is possible to classify complex data set, geological and geophysical borehole data, in order to identify borehole intersects with increased brittle deformation, i.e. brittle deformation zones. The base data used in the study have been provided and delivered by SKB and consist of borehole logging data from the cored borehole KFM03A. The statistical method chosen for this study, cluster analysis using K-means method, groups data into a pre-defined number of clusters with the goal to minimize the variance of data within the group and to maximize the variance between the clusters. The idea is that data can and should be grouped into two categories, two clusters -corresponding to homogeneous bedrock (matrix) in one cluster and open fractures in the other cluster. The analysis also includes a repetition of the cluster analysis, with a stepwise refined data set to see whether strongly accentuated features could be identified. The results show that the use of K-mean Cluster analysis will present clusters that could represent the spatial distribution of bedrock matrix and the location of fractures respectively down the borehole. The results were compared with fracture frequency data (from core mapping) and also with the geological Single Hole Interpretation of KFM03A performed by SKB. The fracture zones identified in the Single Hole Interpretation process are all indicated in the cluster analysis results. The cluster analysis revealed eight additional possible zones. A majority of these are smaller than 5 metres (section width in the borehole) but they are still pronounced in the analysis. Based on the geophysical data, these sections should be taken into

Radiometric calipers for borehole logging

International Nuclear Information System (INIS)

Charbucinski, J.; Wylie, A.W.; Jarrett, R.G.

1976-01-01

Two versions of a radiometric-type caliper for measuring borehole diameter are described. One, based on the bow-spring principle, is suitable for percussion (exploration) drill holes. The other, which utilizes hemispherical wall contactors actuated by springs, is suitable for blast holes. Both utilize low-power radioactive sources and employ a scintillation detector to measure the 'inverse-square law' response of the device to changes in borehole radius. The performance of the device is examined and examples of its use are illustrated. (author)

Drilling of deep boreholes and associated geological investigations. Final disposal of spent fuel

International Nuclear Information System (INIS)

Anttila, P.

1983-12-01

Teollisuuden Voima Oy (Industrial Power Company Ltd.) will take precautions for the final disposal of spent fuel in the Finnish bedrock. The first stage of the site selection studies includes drilling of a deep borehole down to approximately 1000 metres in the winter of 1984. The choice of drilling method and equipment depends on the geological circumstances and the target of the investigation. The most common drilling methods used with the investigations of nuclear waste disposal are diamond core drilling and percussion drilling. The Precambrian bedrock outcropping in Finland exists also in Sweden and Canada, where deep boreholes have been done down to more than 1000 metres using diamond core drilling. This method can be also used in Finland and equipment for the drilling are available. One of the main targets of the investigation is to clarify the true strike and dip of fractures and other discontinuities. The methods used abroad are taking of oriented cores, borehole television survey and geophysical measurements. TV-survey and geophysical methods seem to be most favourable in deep boreholes. Also the accurate position (inclination, bearing) of the borehole is essential to know and many techniques are used for measuring of it. Investigations performed on the core samples include core logging and laboratory tests. For the core logging there is no uniform practice concerning the nuclear waste investigations. Different counries use their own classifications. All of these, however, are based on the petrography and fracture properties of the rock samples. Laboratory tests (petrographical and rock mechanical tests) are generally performed according to the recommendations of international standards. The large volumes of data obtained during investigations require computer techniques which allow more comprehensive collection, storage and processing of data. This kind of systems are already used in Sweden and Canada, for instance, and they could be utilize in Finland

IODP Expedition 340T: Borehole Logging at Atlantis Massif Oceanic Core Complex

Directory of Open Access Journals (Sweden)

Donna Blackman

2013-03-01

Full Text Available Integrated Ocean Drilling Program (IODP Expedition 340T returned to the 1.4-km-deep Hole U1309D at Atlantis Massif to carry out borehole logging including vertical seismic profiling (VSP. Seismic, resistivity, and temperature logs were obtained throughout the geologic section in the footwall of this oceanic core complex. Reliable downhole temperature measurements throughout and the first seismic coverage of the 800–1400 meters below seafloor (mbsf portionof the section were obtained. Distinct changes in velocity, resistivity, and magnetic susceptibility characterize the boundaries of altered, olivine-rich troctolite intervals within the otherwise dominantly gabbroic se-quence. Some narrow fault zones also are associated with downhole resistivity or velocity excursions. Small deviations in temperature were measured in borehole fluid adjacent to known faults at 750 mbsf and 1100 mbsf. This suggests that flow of seawater remains active along these zones of faulting and rock alteration. Vertical seismic profile station coverage at zero offsetnow extends the full length of the hole, including the uppermost 150 mbsf, where detachment processes are expected to have left their strongest imprint. Analysis of wallrock properties, together with alteration and structural characteristics of the cores from Site U1309, highlights the likely interplay between lithology, structure, lithospheric hydration, and core complex evolution.

Logging-while-drilling and wireline velocities: Site NGHP-01-10, Krishna-Godavari Basin, India

Digital Repository Service at National Institute of Oceanography (India)

Jaiswal, P.; Al-Bulushi, S.; Dewangan, P.

is through drilling and logging. Logging is like a surface geophysical survey done in a borehole, only with very limited survey aperture due to close source and receiver spacing. There are two methods of logging. The Wireline method has been in practice... is computed as φt - φs, leaving only three independent parameters. In principle it is possible to vary the four input parameters such that VP and VSwill be independentlymatched at every depth. However, this is not the goal.We aim to adjust the input...

Borehole induction logging for the Dynamic Underground Stripping Project LLNL gasoline spill site

International Nuclear Information System (INIS)

Boyd, S.; Newmark, R.; Wilt, M.

1994-01-01

Borehole induction logs were acquired for the purpose of characterizing subsurface physical properties and monitoring steam clean up activities at the Lawrence Livermore National Laboratory. This work was part of the Dynamic Underground Stripping Project's demonstrated clean up of a gasoline spin. The site is composed of unconsolidated days, sands and gravels which contain gasoline both above and below the water table. Induction logs were used to characterize lithology, to provide ''ground truth'' resistivity values for electrical resistance tomography (ERT), and to monitor the movement of an underground steam plume used to heat the soil and drive volatile organic compounds (VOCs) to the extraction wells

Description of geophysical data in the SKB database GEOTAB. Version 2

International Nuclear Information System (INIS)

Sehlstedt, S.

1991-01-01

For the storage of different types of data collected by SKB a database called GEOTAB has been created. The following data is stored in the database: Background data, geological data, geophysical data, hydrogeological and meteorological data, hydrochemical data, and tracer tests. This report describes the data flow for different types of geophysical measurement. The descriptions start with measurement and end with the storage of data in GEOTAB. Each process and the resulting data volume is presented separately. The geophysical measurements have been divided into the following subjects: Geophysical ground surface measurements, geophysical borehole logging, and petrophysical measurements. Each group of measurements is described in an individual chapter. In each chapter several measuring techniques are described and each method has a data table and a flyleaf table in GEOTAB. (author)

Logs of wells and boreholes drilled during hydrogeologic studies at Lawrence Livermore National Laboratory Site 300, January 1, 1991--September 1, 1992

International Nuclear Information System (INIS)

Crow, N.B.; McConihe, W.L.

1992-01-01

Lawrence Livermore National Laboratory (LLNL) Site 300 is located in the Altamont Hills between Livermore and Tracy, about 18 road miles southeast of Livermore, California. The site is used as a test facility to support national defense research carried out by LLNL. This Addendum 2 to the Logs of Wells and Boreholes Drilled During Hydrogeologic Studies at Lawrence Livermore National Laboratory Site 300 presents hydrogeologic logs for monitor wells and boreholes drilled primarily between January 1, 1991 and September 1, 1992. Some logs drilled earlier and not incorporated in earlier volumes of this document are also included here. A small number of logs drilled before September 1, 1992, are not available at the time of closing the report for publication of this volume (Addendum 2), but will be included in subsequent documents. By September 1, 1992, a total of 495 monitor wells and 285 exploratory boreholes had been drilled at Site 300 since the beginning of hydrogeologic studies in 1982. The primary purpose of these logs is to document lithologic and hydrogeologic conditions together with well completion information. For this reason, not all chemical analytical data are presented. These logs report concentrations of only the most commonly encountered volatile organic compounds, trace metals, and radionuclides detected in ground water and soil samples collected during drilling

Geological and geophysical investigations at Sierra del Medio massif - Argentine

International Nuclear Information System (INIS)

Perucca, J.C.; Llambias, E.; Puigdomenech, H.H.; Cebrelli, E.; Castro, C.E.; Grassi, I.; Salinas, L.I.

1987-01-01

Geological investigations were performed at Sierra del Medio (Chubut Province), a mountainous massif of about 25 km by 8 km of migmatic origin, which emerges from a depressed tectonic trench or graben called Pampa de Gastre. The most ancient rocks belong to biotitic and anphibolic schist that passed almost entirely to tonalitoid migmatites with a second process producing granitic rocks. Boreholes were drilled on the basis of conclusions from Landsat satellites imagery and aerial photographic sets, folowed by field work on geological, petrographic, geophysical and hydrogeological features at surface, structural interpretation supported by geostatistical computations. Two sets of boreholes were drilled to investigate subsurface rock behaviour al 300 m depth and 800 m depth respectively, beginning at peripheral places and ending at the central part or selected site. Basic purposes of boreholes were to define structural and petrographic features of the rock massif by a good comprehension of master joints and faulting distribution with its belts of alteration mylonitization or brecciation, mechanical properties of samples, chemical composition and varitions, petrographic facies and mineralogy. Boreholes provided data to investigate joints, faults and dikes as general discontinuities for hydraulic research like permeability or effective hydraulic conductivity, and their geostatistical modelling. Boreholes are also being prepared for geophysical logging from which logthermal ones have already been completed. (Author) [es

Nuclear well logging in hydrology

International Nuclear Information System (INIS)

1971-01-01

they are described in detail elsewhere. The tracer techniques which have been included involve the use of well-logging methods to locate isotopic tracers inserted either in an adjacent borehole or in the same borehole as that in which the logs are made. Throughout the report, sufficient references have been selected to ensure that proven methods are adequately represented, but a comprehensive bibliography is not included. The International Atomic Energy Agency, at the request of the Coordinating Council of the International Hydrological Decade, is providing the Secretariat for the Working Group on Nuclear Techniques in Hydrology of the International Hydrological Decade (IHD). The Working Group and Secretariat have contributed to and coordinated the preparation of this report as well as an earlier more general report, Guidebook on Nuclear Techniques in Hydrology, IAEA Technical Reports Series No.91. Nuclear logging, along with other borehole geophysical methods, was adopted and developed primarily by the petroleum industry for use in exploration and developmental work. The information in this report shows that nuclear logging may also be useful in hydrology. Qualitative and under proper conditions quantitative interpretations about the physical, chemical, petrographic and hydraulic properties of formations and their contained fluids can be made from nuclear logs. The IHD Working Group on Nuclear Techniques in Hydrology, during its fourth meeting (in 1969), considered in detail the present status of nuclear logging with respect to hydrological investigations. Particularly it considered: (1) whether suitable equipment is at present available; (2) whether it could fulfil the need of hydrologists today; and (3) whether it was yet economic for use in hydrological investigations. The Working Group noted that the two main deficiencies in nuclear logging for hydrological purposes are: (1) the general lack of information in a coordinated form, and (2) the scarcity of

Calibration models for density borehole logging - construction report

International Nuclear Information System (INIS)

Engelmann, R.E.; Lewis, R.E.; Stromswold, D.C.

1995-10-01

Two machined blocks of magnesium and aluminum alloys form the basis for Hanford's density models. The blocks provide known densities of 1.780 ± 0.002 g/cm 3 and 2.804 ± 0.002 g/cm 3 for calibrating borehole logging tools that measure density based on gamma-ray scattering from a source in the tool. Each block is approximately 33 x 58 x 91 cm (13 x 23 x 36 in.) with cylindrical grooves cut into the sides of the blocks to hold steel casings of inner diameter 15 cm (6 in.) and 20 cm (8 in.). Spacers that can be inserted between the blocks and casings can create air gaps of thickness 0.64, 1.3, 1.9, and 2.5 cm (0.25, 0.5, 0.75 and 1.0 in.), simulating air gaps that can occur in actual wells from hole enlargements behind the casing

Nuclear geophysical methods for exploration of wells in fields of solid mineral deposits

International Nuclear Information System (INIS)

Fel'dman, I.I.; Blyumentsev, A.M.; Karnikolo, V.F.; Zheltikov, A.N.

1974-01-01

Chromite and sulphur deposits have been used to illustrate the necessity and desirabilty of applying a combination of nuclear-geophysics logging methods and correlations between individual rock and ore components for localization and evaluation of ore bodies in borehole sections. On chromite deposits the combination includes neutron-capture spectrometric gamma-logging, epithermal neutron-neutron logging, selective gamma-gamma logging and gamma-gamma density logging. Neutron-capture spectrometric gamma-logging ensures an unambiguous localization of ores in borehole sections; epithermal neutron-neutron logging enables ores to be separated by the degree of dissemination; selective gamma-gamma logging is used to determine the content of Cr 2 O 3 and gamma-gamma density logging determines the volume weight. In addition a close correlation between Cr 2 O 3 and SiO 2 contents allows the silica content to be estimated. Application of a three-channel apparatus of the RSK-3 type ensures that all the measurements are made in two descent-ascension operations. The implementation of the combination described has ensured transition to drilling with a reduced selection of core samples. On sulphur deposits of carbonate type the combination includes epithermal neutron-neutron logging, gamma-gamma density logging and neutron-capture spectrometric gamma-logging

Geophysical drillhole logging of the drillholes OL-KR40, OL-KR41, OL-KR41B, OL-KR42, OLKR42B, OL-KR43 and OL-KR43B, at Olkiluoto 2006 and 2007

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2007-05-01

Suomen Malmi Oy conducted geophysical borehole logging of the boreholes drillholes OL-KR40, OL-KR41, OL-KR41B, OL-KR42, OL-KR42B, OL-KR43 and OL-KR43B at the Olkiluoto site in Eurajoki during August, September, December 2006 and January 2007. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and processing of the acoustic data. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

Interpretation of geophysical well-log measurements in drill hole UE25a-1, Nevada Test Site, Radioactive Waste Program

International Nuclear Information System (INIS)

Hagstrum, J.T.; Daniels, J.J.; Scott, J.H.

1980-01-01

An exploratory hole (UE25a-1) was drilled at Nevada Test Site (NTS) to determine the suitability of pyroclastic deposits as storage sites for radioactive waste. Studies have been conducted to investigate the stratigraphy, structure, mineralogy, petrology, and physical properties of the tuff units encountered in the drill hole. This report deals with the interpretation of physical properties for the tuff units from geophysical well-log measurements. The ash-flow and bedded tuff sequences at NTS comprise complex lithologies of variously welded tuffs with superimposed crystallization and altered zones. To characterize these units, resistivity, density, neutron, gamma-ray, induced polarization, and magnetic susceptibility geophysical well-log measurements were made. Although inherently subjective, a consistent interpretation of the well-log measurements was facilitated by a computer program designed to interpret well logs either individually or simultaneously. The broad features of the welded tuff units are readily distinguished by the geophysical well-log measurements. However, many details revealed by the logs indicate that more work is necessary to clarify the casual elements of well-log response in welded tuffs

Completion summary for boreholes TAN-2271 and TAN‑2272 at Test Area North, Idaho National Laboratory, Idaho

Science.gov (United States)

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

2016-06-30

255 ft BLS and the second between 272 and 282 ft BLS. Basalt texture for borehole TAN-2271 generally was described as aphanitic, phaneritic, and porphyritic. Sediment layers, starting near 122 ft BLS, generally were composed of fine-grained sand and silt with a lesser amount of clay. Basalt flows generally ranged in thickness from 2 to 78 ft and varied from highly fractured to dense with high to low vesiculation. Geophysical data and limited core material collected from TAN-2272 show similar lithologic sequences to those reported for TAN-2271.Geophysical and borehole video logs were collected during certain stages of the drilling and construction process at boreholes TAN-2271 and TAN-2272. Geophysical logs were examined synergistically with available core material to confirm geologic and hydrologic similarities and suggest possible fractured network interconnection between boreholes TAN-2271 and TAN-2272. Natural gamma log measurements were used to assess the completeness of the vapor port lines behind 10-in. diameter well casing. Electromagnetic flow meter results were used to identify downward flow conditions that exist for boreholes TAN-2271 and TAN-2272. Furthermore, gyroscopic deviation measurements were used to measure horizontal and vertical displacement at all depths in boreholes TAN-2271 and TAN-2272.After borehole construction was completed, single‑well aquifer tests were done within wells TAN-2271 and TAN‑2272 to provide estimates of transmissivity and hydraulic conductivity. The transmissivity and hydraulic conductivity were estimated for the pumping well and observation well during the aquifer tests conducted on August 25 and August 27, 2015. Estimates for transmissivity range from 4.1 . 103 feet squared per day (ft2/d) to 8.1 . 103 ft2/d; estimates for hydraulic conductivity range from 5.8 to 11.5 feet per day (ft/d). Both TAN-2271 and TAN‑2272 show sustained pumping rates of about 30 gallons per minute (gal/min) with measured drawdown in the

Automated recognition of stratigraphic marker shales from geophysical logs in iron ore deposits

Science.gov (United States)

Silversides, Katherine; Melkumyan, Arman; Wyman, Derek; Hatherly, Peter

2015-04-01

The mining of stratiform ore deposits requires a means of determining the location of stratigraphic boundaries. A variety of geophysical logs may provide the required data but, in the case of banded iron formation hosted iron ore deposits in the Hamersley Ranges of Western Australia, only one geophysical log type (natural gamma) is collected for this purpose. The information from these logs is currently processed by slow manual interpretation. In this paper we present an alternative method of automatically identifying recurring stratigraphic markers in natural gamma logs from multiple drill holes. Our approach is demonstrated using natural gamma geophysical logs that contain features corresponding to the presence of stratigraphically important marker shales. The host stratigraphic sequence is highly consistent throughout the Hamersley and the marker shales can therefore be used to identify the stratigraphic location of the banded iron formation (BIF) or BIF hosted ore. The marker shales are identified using Gaussian Processes (GP) trained by either manual or active learning methods and the results are compared to the existing geological interpretation. The manual method involves the user selecting the signatures for improving the library, whereas the active learning method uses the measure of uncertainty provided by the GP to select specific examples for the user to consider for addition. The results demonstrate that both GP methods can identify a feature, but the active learning approach has several benefits over the manual method. These benefits include greater accuracy in the identified signatures, faster library building, and an objective approach for selecting signatures that includes the full range of signatures across a deposit in the library. When using the active learning method, it was found that the current manual interpretation could be replaced in 78.4% of the holes with an accuracy of 95.7%.

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

International Nuclear Information System (INIS)

Labbas, K.

1997-01-01

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

Status report on the development of a prompt fission neutron uranium borehole logging technique

International Nuclear Information System (INIS)

Smith, G.W.

1977-05-01

The prompt fission neutron (PFN) method of direct uranium measurement was studied. The PFN uranium logging technique measures the enhanced epithermal neutron population created by the prompt thermal fission of 235 U to assay uranium mineralization around a borehole. This neutron population exists for several hundred microseconds after a pulsed neutron source produces a burst of high energy (14 MeV) neutrons. A feasibility study established the basic relationship between the uranium concentration and the enhanced epithermal neutron count, and defined the major measurement perturbing factors. Following the feasibility study, development of a PFN prototype field probe was undertaken. A laboratory type neutron generator, the Controlatron, was modified for use in the probe. Field evaluation of the prototype system began in January 1976. Comparisons of neutron logs and natural gamma logs taken during this evaluation period clearly define many disequilibrium conditions as verified by ore grade estimates from core samples. The feasibility of the PFN logging technique to detect uranium in-situ has now been demonstrated

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

Science.gov (United States)

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

2015-01-01

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

Drilling and the associated borehole measurements of the pilot hole ONK-PH2

International Nuclear Information System (INIS)

Oehberg, A.; Aaltonen, I.; Kemppainen, K.; Mattila, J.; Heikkinen, E.; Lahti, M.; Pussinen, V.; Niemonen, J.; Paaso, N.; Rouhiainen, P.

2005-11-01

The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH2 was drilled in December 2004. The length of the borehole is about 122 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity and hydraulic head in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Geophysical borehole logging and optical imaging surveys of the pilot hole PH2 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the geochemical study was to get information of composition of ONKALO's groundwater before the construction will

Drilling and the associated borehole measurements of the pilot hole ONK-PH3

International Nuclear Information System (INIS)

Oehberg, A.; Heikkinen, E.; Hirvonen, H.; Kemppainen, K.; Majapuro, J.; Niemonen, J.; Poellaenen, J.; Rouhiainen, P.

2006-03-01

The construction of the ONKALO access tunnel started in September 2004 at Olkiluoto. Most of the investigations related to the construction of the access tunnel aim to ensure successful excavations, reinforcement and sealing. Pilot holes are boreholes, which are core drilled along the tunnel profile. The length of the pilot holes typically varies from several tens of metres to a couple of hundred metres. The pilot holes will mostly aim to confirm the quality of the rock mass for tunnel construction, and in particular at identifying water conductive fractured zones and at providing information that could result in modifications of the existing construction plans. The pilot hole ONK-PH3 was drilled in September 2005. The length of the borehole is 145.04 metres. The aim during the drilling work was to orientate core samples as much as possible. The deviation of the borehole was measured during and after the drilling phase. Electric conductivity was measured from the collected returning water samples. Logging of the core samples included the following parameters: lithology, foliation, fracturing, fracture frequency, RQD, fractured zones, core loss and weathering. The rock mechanical logging was based on Q-classification. The tests to determine rock strength and deformation properties were made with a Rock Tester-equipment. Difference Flow method was used for the determination of hydraulic conductivity in fractures and fractured zones in the borehole. The overlapping i.e. the detailed flow logging mode was used. The flow logging was performed with 0.5 m section length and with 0.1 m depth increments. Water loss tests (Lugeon tests) and a pressure build-up test were used to give background information for the grouting design. Geophysical borehole logging and optical imaging surveys of the pilot hole PH3 included the field work of all the surveys, the integration of the data as well as interpretation of the acoustic and borehole radar data. One of the objectives of the

BoreholeAR: A mobile tablet application for effective borehole database visualization using an augmented reality technology

Science.gov (United States)

Lee, Sangho; Suh, Jangwon; Park, Hyeong-Dong

2015-03-01

Boring logs are widely used in geological field studies since the data describes various attributes of underground and surface environments. However, it is difficult to manage multiple boring logs in the field as the conventional management and visualization methods are not suitable for integrating and combining large data sets. We developed an iPad application to enable its user to search the boring log rapidly and visualize them using the augmented reality (AR) technique. For the development of the application, a standard borehole database appropriate for a mobile-based borehole database management system was designed. The application consists of three modules: an AR module, a map module, and a database module. The AR module superimposes borehole data on camera imagery as viewed by the user and provides intuitive visualization of borehole locations. The map module shows the locations of corresponding borehole data on a 2D map with additional map layers. The database module provides data management functions for large borehole databases for other modules. Field survey was also carried out using more than 100,000 borehole data.

Evaluation of geophysical techniques for identifying fractures in program wells in Deaf Smith County, Texas: Revision 1, Topical report

International Nuclear Information System (INIS)

Gillespie, R.P.; Siminitz, P.C.

1987-08-01

Quantitative information about the presence and orientation of fractures is essential for the understanding of the geomechanical and geohydrological behavior of rocks. This report evaluates various borehole geophysical techniques for characterizing fractures in three Civilian Radioactive Waste Management (CRWM) Program test wells in the Palo Duro Basin in Deaf Smith County, Texas. Emphasis has been placed on the Schlumberger Fracture Identification Log (FIL) which detects vertical fractures and provides data for calculation of orientation. Depths of FIL anomalies were compared to available core. It was found that the application of FIL results to characterize fracture frequency or orientation is inappropriate at this time. The uncertainties associated with the FIL information render the information unreliable. No geophysical logging tool appears to unequivocally determine the location and orientation of fractures in a borehole. Geologic mapping of the exploratory shafts will ultimately provide the best data on fracture frequency and orientation at the proposed repository site. 22 refs., 6 figs., 3 tabs

Estimated method of permeability in the granitic rocks by geophysical loggings; Butsuri kenso shuho ni yoru kakoganchu no tosuisei ni kansuru ichikosatsu

Energy Technology Data Exchange (ETDEWEB)

Matsuoka, K; Hashimoto, N. [Geophysical Surveying and Consulting Co. Ltd., Tokyo (Japan)]Ogata, N. [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

1997-10-22

Water permeability in granite is estimated by performing geophysical investigation using a 500m-deep test hole drilled in granitic rocks in the vicinity of a Tono mine. The investigation consists of flowmeter logging and geophysical logging. In flowmeter logging, a probe is moved up and down in the hole at a constant speed by use of a cable, and the cable speed and impeller revolution are used to workout the relative speed of the fluid in the hole. In the geophysical logging, a probe attached to the leading end of a logging cable is replaced with other probes so as to acquire different geophysical data. In a hole drilled in a crack-abundant rockbed such as a granitic rockbed, the inflow and outflow of ground water is governed mainly by water-permeable crack zones, and the result of the flowmeter logging show that this hole has three highly water-permeable zones. Using the results of the loggings, a correlative equation is worked out between changes in flow speed and changes in permeability index obtained by hydraulics tests. Among the various results achieved by the geophysical logging, a fine correlationship is found between an equation relative to permeability obtained using electricity and density and water-permeability indexes obtained by hydraulic tests conducted in situ. 4 refs., 8 figs., 1 tab.

ANDRILL Borehole AND-1B: Well Log Analysis of Lithofacies and Glacimarine Cycles.

Science.gov (United States)

Jackolski, C. L.; Williams, T.; Powell, R. D.; Jarrard, R.; Morin, R. H.; Talarico, F. M.; Niessen, F.; Kuhn, G.

2008-12-01

During the 2006-2007 austral summer, the Antarctic geological drilling program ANDRILL recovered cores of sedimentary rock from a 1285-m-deep borehole below the McMurdo Ice Shelf. Well logging instruments were deployed to a depth of 1017 mbsf after core recovery. This study focuses on two intervals of the AND-1B borehole: upper HQ (238-343 mbsf; Pliocene) and NQ (698-1017 mbsf; upper Miocene), which were logged with natural gamma ray, induction resistivity and magnetic susceptibility tools. To understand how the well logs fit into a more complete physical properties data set, we performed factor and cluster analyses on a suite of well logs and core logs in the upper HQ and NQ intervals. In both intervals, factor analysis groups resistivity and core P-velocity into a factor that we interpret as being inversely proportional to porosity. It also groups natural gamma and potassium (from the XRF core scanner) into a factor that we interpret as a particle-size or lithology index. An additional factor in the NQ interval, influenced by clast number and magnetic susceptibility, distinguishes subglacial diamictites from other lithofacies. The factors in each interval (2 in HQ, 3 in NQ) are used as input to cluster analysis. The results are log data objectively organized into clusters, or electrofacies. We compare these electrofacies to the lithofacies, well logs and unconformity-bounded glacimarine cycles of AND-1B. Patterns in the glacimarine cycles are observed in the well logs and electrofacies. In the NQ glacimarine sediments, an electrofacies pattern is produced between subglacial diamictites at the bottom of each sequence and the glacial retreat facies above. Subglacial diamictites have higher values for the additional NQ factor, corresponding to clast number and magnetic susceptibility, than the muds and sands that form the retreat facies. Differences in the porosity factor are not observed in any electrofacies pattern in the NQ interval, but subtle patterns in the

Borehole Logging and Slug Tests for Evaluating the Applicability of Electrical Resistivity Tomography for Groundwater Exploration in Nampula Complex, Mozambique

Directory of Open Access Journals (Sweden)

Farisse Chirindja

2017-02-01

Full Text Available In Nampula province, Mozambique, there is a high number of water wells considered as having failed for having too low a pumping yield. Two Electrical Resistivity Tomography (ERT measurement campaigns were conducted in the area for evaluating the reasons of failures. However, in some cases it was difficult to verify and interpret the ERT results by only using the inadequate lithological description presented in drilling reports. In this paper the integration of borehole logging and slug testing is presented as a solution to add more information and to enhance the interpretation of ERT models. The borehole logging tool measured resistivity, magnetic susceptibility and natural gamma. The logging results proved that the ERT models are accurate in estimating the resistivity for basement (>1400 Ωm, fractured layer (220–1400 Ωm, semi-weathered layer with clay accumulation (10–220 Ωm, and weathered and leached layer (220–2700 Ωm. The slug testing gave results of high hydraulic conductivity (K values where the ERT indicates well-developed weathered and fractured layers, and low K values where these are less developed. The borehole interpretation can be extrapolated using the ERT model to give a geometric characterization of the aquifer. Therefore, the implementation of the ERT method in groundwater exploration is encouraged.

The Nirex Sellafield site investigation: the role of geophysical interpretation

International Nuclear Information System (INIS)

Muir Wood, R.; Woo, G.; MacMillan, G.

1992-01-01

This report reviews the methods by which geophysical data are interpreted, and used to characterize the 3-D geology of a site for potential storage of radioactive waste. The report focuses on the NIREX site investigation at Sellafield, for which geophysical observations provide a significant component of the structural geological understanding. In outlining the basic technical principles of seismic data processing and interpretation, and borehole logging, an attempt has been made to identify errors, uncertainties, and the implicit use of expert judgement. To enhance the reliability of a radiological probabilistic risk assessment, recommendations are proposed for independent use of the primary NIREX geophysical site investigation data in characterizing the site geology. These recommendations include quantitative procedures for undertaking an uncertainty audit using a combination of statistical analysis and expert judgement. (author)

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

International Nuclear Information System (INIS)

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

Processing well logging data, for example for verification and calibration of well logs

International Nuclear Information System (INIS)

Suau, J.; Boutemy, Y.

1981-01-01

A method is described of machine processing well logging data derived from borehole exploring devices which investigate earth formations traversed by boreholes. The method can be used for verifying and recalibrating logs, reconstructing missing logs and combining the data to form a statistical model of the traversed earth formations. (U.K.)

Borehole Breakout Growth and In-Situ Stress Orientation in the Central Scandinavian Caledonides: Results from the Cosc-1 Borehole

Science.gov (United States)

Wenning, Q.; Zappone, A.; Berthet, T.; Ask, M. V. S.; Rosberg, J. E.; Almqvist, B. S. G.

2017-12-01

Borehole breakouts are often assumed to form near instantaneously due to stress perturbations around boreholes after the rock mass was removed. Recent observations in sediments [e.g., Moore et al., 2011] and crystalline rocks [e.g., Berard and Cornet, 2003], as well as numerical modelling results [e.g., Schoenball et al., 2014], suggest that there are cases in which borehole breakout grows radially over time, forcing us to reconsider subsurface stress estimation. These observations are rare due to drilling difficulties (i.e., cementing and casing the borehole after drilling), often only allowing a single image logging campaign. In 2014, the Collisional Orogeny in the Scandinavian Caledonides deep scientific borehole (COSC-1) was drilled to a depth of 2.5 km. To date the borehole is open and uncased, allowing two acoustic televiewer logging campaigns, with more than one year between campaigns. The borehole is still available for supplementary data collactions. These logs provide detailed images along the full length of the 2.5 km deep borehole with 1.6 km of overlapping logs for breakout and drilling induced tensile fracture analysis. The results show from the sparse occurrence of breakouts and drilling induced tensile fractures a NW-SE average maximum horizontal stress direction, consistent with the general trend in Scandinavia. The unique acquisition of image logs in two successions allows for analysis of time-dependent borehole deformation, indicating that six breakout zones have crept, both along the borehole axis and radially (up to 20° growth) around the borehole. While some breakouts have grown, the formation of new breakouts has not occurred. The occurrence of breakouts and their growth appear to be independent of lithology. The observed growth after the second logging campaign suggests that under conditions where the stress exceeded the strength of the rock, the resulting breakout causes perturbations in the stresses around the borehole in the near

Geophysical characterization of an active hydrothermal shear zone in granitic rocks

Science.gov (United States)

Zahner, Tobias; Baron, Ludovic; Holliger, Klaus; Egli, Daniel

2016-04-01

Hydrothermally active faults and shear zones in the crystalline massifs of the central Alps are currently of particular interest because of their potential similarities and analogies with planned deep petrothermal reservoirs in the Alpine foreland. In order to better understand such hydrothermal systems, a near-vertical, hydrothermally active shear zone embedded in low-permeability granitic rocks has been drilled. This borehole is located on the Grimsel Pass in the central Swiss Alps, has an inclination of 24 degrees with regard to the vertical, and crosses the targeted shear zone between about 82 and 86 meters depth. The borehole has been fully cored and a comprehensive suite of geophysical logging data has been acquired. The latter comprises multi-frequency sonic, ground-penetrating radar, resistivity, self-potential, gamma-gamma, neutron-neutron, optical televiewer, and caliper log data. In addition to this, we have also performed a surface-to-borehole vertical seismic profiling experiment. The televiewer data and the retrieved core samples show a marked increase of the fracture density in the target region, which also finds its expression in rather pronounced and distinct signatures in all other log data. Preliminary results point towards a close correspondence between the ground-penetrating radar and the neutron-neutron log data, which opens the perspective of constraining the effective fracture porosity at vastly differing scales. There is also remarkably good agreement between the sonic log and the vertical seismic profiling data, which may allow for assessing the permeability of the probed fracture network by interpreting these data in a poroelastic context.

Completion summary for boreholes USGS 140 and USGS 141 near the Advanced Test Reactor Complex, Idaho National Laboratory, Idaho

Science.gov (United States)

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

2014-01-01

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

Preliminary analysis of downhole logging data from ICDP Lake Junin drilling Project, Peru

Science.gov (United States)

Pierdominici, Simona; Kück, Jochem; Rodbell, Donald T.; Abbott, Mark B.

2016-04-01

The International Continental Drilling Programm (ICDP) has supported a scientific drilling campaign in Peru during the summer season 2015. The Lake Junin Drilling Project mainly aims at obtaining high-resolution paleoclimate records from lacustrine sediments to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is located at 4000 m a.s.l. in the tropical Andes of Peru, and is characterized by a thick (> 125 m) sediment package deposited at a high rate (0.2 to 1.0 mm yr-1). Lake Junín is one of the few lakes in the tropical Andes that predates the maximum extent of glaciation and is in a geomorphic position to record the waxing and waning of glaciers in nearby cordillera, hence making the lake a key site for the investigation of the Quaternary climate evolution in the inner-tropics of the Southern Hemisphere. Continous coring was performed at three sites in overall 11 boreholes on the lake with at least two overlapping boreholes per site to avoid core gaps. The depth of the boreholes varied between approx. 30 m and 110 m depending on the drill site. The core bit had a bit size of 122.6 mm and yielded a core diameter of 85 mm. Upon completion of coring operations downhole geophysical logging was performed in five of the 11 boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. The main objective was to record in-situ the physical properties of the lacustrine sediments of Lake Junin. Downhole logs provide a powerful tool to fill in information at intervals with core gaps and as depth reference for depth matching of the discontinous cores. Furthermore it will be used for the lithological reconstruction and interpretation. The OSG downhole logging comprised total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic P-wave velocity. Unstable and collapsing borehole walls made it neccessary to carry out logging in several sections instead of in one run. The

Geothermal regime of Tarim basin, NW China: insights from borehole temperature logging

Science.gov (United States)

Liu, S.; Lei, X.

2013-12-01

Geothermal regime of sedimentary basin is vital for understanding basin (de)formation process, hydrocarbon generation status and assessing the resource potential. Located at the Precambrian craton block, the Tarim basin is the largest intermountain basin in China, which is also the ongoing target of oil and gas exploration. Previous knowledge of thermal regime of this basin is from limited oil exploration borehole testing temperature, the inherent deficiency of data of this type makes accurate understanding of its thermal regime impossible. Here we reported our latest steady temperature logging results in this basin and analyze its thermal regime as well. In this study, 10 temperature loggings are conducted in the northern Tarim basin where the major oil and gas fields are discovered. All the boreholes for temperature logging are non-production wells and are shut in at least more than 2~3 years, ensuring the temperature equilibrium after drilling. The derived geothermal gradient varies from 20.2 to 26.1 degree/km, with a mean of 22.0 degree/km. However, some previous reported gradients in this area are obviously lower than our results; for example, the previous gradient of THN2 well is 13.2 degree/km but 23.2 degree/km in this study, and not enough equilibrium time in previous logging accounts for this discrepancy. More important, it is found that high gradients usually occur in the gas field and the gradients of the gas fields are larger than those in other oil fields, indicating higher thermal regime in gas field. The cause of this phenomenon is unclear, and the upward migration of hot fluid along fault conduit is speculated as the possible mechanism for this high geothermal anomaly in the oil and gas fields. Combined with measured thermal conductivity data, 10 new heat flow values are also achieved, and the heat flow of the Tarim basin is between 38mW/m2 and 52mW/m2, with a mean of 43 mW/m2. This relatively low heat flow is coincident with that of typical

The application of radiation logs to groundwater hydrology

Energy Technology Data Exchange (ETDEWEB)

Scott Keys, W [United States Geological Survey, Denver, CO (United States)

1967-05-15

The drilling of exploratory holes to determine the availability of groundwater and to plan the most economical methods of water development is expensive. The only technique available at present for obtaining geological and hydrological information through the casing of pre-existing water wells and other boreholes is by radiation logging. Up to now these logging techniques have been little used in groundwater hydrology. This report describes inexpensive portable radiation logging equipment that is available or has been developed for groundwater studies in connection with a general research project on the application of borehole geophysics in groundwater hydrology. It is possible to obtain data on the following: the source, velocity, and chemical quality of groundwater; the location, extent, geometry, bulk density, porosity, permeability, and specific yield of aquifers and associated strata; and the position of casings, casing collars, leaks, perforations, and cement. The radiation logs employed include natural gamma, gamma-gamma, neutron-gamma. neutron epithermal-neutron. and radioactive tracer. The following radioisotopes are utilized: cobalt-60, plutonium-239, americium-241, and iodine-131. Typical radiation logs obtained by the various techniques are described and examples are given of practical applications of radiation logging to groundwater investigations. The applications cited are studies of perched water in basaltic rocks and associated sedimentary strata; the porosity, moisture content, and position of zones into which water was injected in volcanic tuff; the position of the interface between brine and fresh water in fine-grained carbonate rocks and associated fine clastic rocks; the interpretation of porosity from a neutron log; and the location by means of a radioactive tracer of the more permeable fracture zones in a well penetrating crystalline rock. (author)

Informing groundwater model hydrostratigraphy with airborne time-domain electromagnetic data and borehole logs

DEFF Research Database (Denmark)

Marker, Pernille Aabye; Bauer-Gottwein, Peter; Mosegaard, Klaus

lithological information directly into groundwater models is proposed. The approach builds on a clay-fraction inversion which is a spatially variable translation of resistivity values from EM data into clay-fraction values using borehole lithological information. Hydrostratigraphical units are obtained through...... a k-means cluster analysis of the principal components of resistivity and clay-fraction values. Under the assumption that the units have uniform hydrological properties, the units constitute the hydrostratigraphy for a groundwater model. Only aquifer structures are obtained from geophysical...... and lithological data, while the estimation of the hydrological properties of the units is inversely derived from the groundwater model and hydrological data. A synthetic analysis was performed to investigate the principles underlying the clustering approach using three petrophysical relationships between...

hp-HGS strategy for inverse 3D DC resistivity logging measurement simulations

KAUST Repository

Gajda-Zaǵorska, Ewa; Paszý nski, Maciej; Schaefer, Robert; Pardo, David; Calo, Victor M.

2012-01-01

In this paper we present a twin adaptive strategy hp-HGS for solving inverse problems related to 3D DC borehole resistivity measurement simulations. The term “simulation of measurements” is widely used by the geophysical community. A quantity of interest, voltage, is measured at a receiver electrode located in the logging instrument. We use the self-adaptive goal-oriented hp-Finite Element Method (hp-FEM) computer simulations of the process of measurements in deviated wells (when the angle between the borehole and formation layers are < 90 deg). We also employ the hierarchical genetic search (HGS) algorithm to solve the inverse problem. Each individual in the population represents a single configuration of the formation layers. The evaluation of the individual is performed by solving the direct problem by means of the hp-FEM algorithm and by comparison with measured logging curve. We conclude the paper with some discussion on the parallelization of the algorithm.

hp-HGS strategy for inverse 3D DC resistivity logging measurement simulations

KAUST Repository

Gajda-Zaǵorska, Ewa

2012-06-02

In this paper we present a twin adaptive strategy hp-HGS for solving inverse problems related to 3D DC borehole resistivity measurement simulations. The term “simulation of measurements” is widely used by the geophysical community. A quantity of interest, voltage, is measured at a receiver electrode located in the logging instrument. We use the self-adaptive goal-oriented hp-Finite Element Method (hp-FEM) computer simulations of the process of measurements in deviated wells (when the angle between the borehole and formation layers are < 90 deg). We also employ the hierarchical genetic search (HGS) algorithm to solve the inverse problem. Each individual in the population represents a single configuration of the formation layers. The evaluation of the individual is performed by solving the direct problem by means of the hp-FEM algorithm and by comparison with measured logging curve. We conclude the paper with some discussion on the parallelization of the algorithm.

Generation and performance of a multigroup coupled neutron-gamma cross-section library for deterministic and Monte Carlo borehole logging analysis

International Nuclear Information System (INIS)

Kodeli, I.; Aldama, D. L.; De Leege, P. F. A.; Legrady, D.; Hoogenboom, J. E.; Cowan, P.

2004-01-01

As part of the IRTMBA (Improved Radiation Transport Modelling for Borehole Applications) project of the EU community's 5. framework program a special purpose multigroup cross-section library was prepared for use in deterministic and Monte Carlo oil well logging particle transport calculations. This library is expected to improve the prediction of the neutron and gamma spectra at the detector positions of the logging tool, and their use for the interpretation of the neutron logging measurements was studied. Preparation and testing of this library is described. (authors)

Well logging with natural gamma radiation

International Nuclear Information System (INIS)

Ellis, D.V.

1983-01-01

An invention is described for use in natural gamma radiation well logging in which measurements taken in a borehole are used in the search for valuable underground resources such as oil or gas. The invention comprises deriving a log of natural gamma radiation detected in selected energy windows for a selected borehole depth interval and converting it into a log of the selected subsurface materials, e.g. Th, U, K. This log is corrected for the effects of 1) either a gamma ray emitter in the borehole fluid, e.g. potassium salts and/or 2) a gamma ray attenuator in the borehole fluid, e.g. a strong attenuator such as barite and/or hematite. The Th, U, K log is particularly useful in the exploration of oil and gas resources since the Th, U, K concentrations are a good indication as to the presence, type and volume of shale and clay in the formations surrounding the borehole. (U.K.)

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

Science.gov (United States)

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

2016-04-01

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

Modeling and Evaluation of Geophysical Methods for Monitoring and Tracking CO2 Migration

Energy Technology Data Exchange (ETDEWEB)

Daniels, Jeff

2012-11-30

Geological sequestration has been proposed as a viable option for mitigating the vast amount of CO{sub 2} being released into the atmosphere daily. Test sites for CO{sub 2} injection have been appearing across the world to ascertain the feasibility of capturing and sequestering carbon dioxide. A major concern with full scale implementation is monitoring and verifying the permanence of injected CO{sub 2}. Geophysical methods, an exploration industry standard, are non-invasive imaging techniques that can be implemented to address that concern. Geophysical methods, seismic and electromagnetic, play a crucial role in monitoring the subsurface pre- and post-injection. Seismic techniques have been the most popular but electromagnetic methods are gaining interest. The primary goal of this project was to develop a new geophysical tool, a software program called GphyzCO2, to investigate the implementation of geophysical monitoring for detecting injected CO{sub 2} at test sites. The GphyzCO2 software consists of interconnected programs that encompass well logging, seismic, and electromagnetic methods. The software enables users to design and execute 3D surface-to-surface (conventional surface seismic) and borehole-to-borehole (cross-hole seismic and electromagnetic methods) numerical modeling surveys. The generalized flow of the program begins with building a complex 3D subsurface geological model, assigning properties to the models that mimic a potential CO{sub 2} injection site, numerically forward model a geophysical survey, and analyze the results. A test site located in Warren County, Ohio was selected as the test site for the full implementation of GphyzCO2. Specific interest was placed on a potential reservoir target, the Mount Simon Sandstone, and cap rock, the Eau Claire Formation. Analysis of the test site included well log data, physical property measurements (porosity), core sample resistivity measurements, calculating electrical permittivity values, seismic data

Linking downhole logging data and clay mineralogy analysis in the ICDP Lake Junín drilling Project, Peru

Science.gov (United States)

Pierdominici, S.; Schleicher, A.; Kueck, J.; Rodbell, D. T.; Abbott, M. B.

2017-12-01

The lake Junin drilling project, co-funded by the International Continental Drilling Program (ICDP), is located at 4000 m a.s.l. in the tropical Andes of Peru. Several boreholes were drilled with the goal to obtain both high-resolution paleoclimate records from lacustrine sediments and to reconstruct the history of the continental records covering the glacial-interglacial cycles. Lake Junín is characterized by a thick package of lacustrine sediments (> 125 m) deposited at a high rate (0.2 to 1.0 mm yr-1), and it is one of the few lakes in the tropical Andes that is hundreds of thousands of years old with a continuous sedimentation rate preserving a very long and continuous record of past ice age cycles. The boreholes reached a maximum depth of 110.08 m and continuous coring was performed at three sites with 11 boreholes. Additionally, an extensive geophysical downhole logging campaign was performed on five boreholes (1A, 1C, 1D, 2A and 3B) by the Operational Support Group of ICDP. Downhole logging measurements comprise total and spectrum gamma ray, magnetic susceptibility, borehole geometry, temperature, and sonic p-wave velocity. In order to fit the downhole logging depths to the composite profile depths, each borehole was depth-matched with the core data. Interpreting the downhole logging data permits to establish a complete lithological log, to characterize the in-situ physical properties of drilled lacustrine sediments, to determine sedimentary structures and to obtain evidences about palaeoclimatic conditions during up to 200 ka. Th and K values are used as a proxy for a first estimate and characterization of clay content in the sediments, which are present as montmorillonite, smectite, illite, and kaolinite in different amounts. Linking the clay minerals that occur in the core material with the downhole logging data allows assessing the geological history of the lake and the relationship to climate change processes. Additional laboratory analysis will be

Prediction of thermal conductivity of sedimentary rocks from well logs

DEFF Research Database (Denmark)

Fuchs, Sven; Förster, Andrea

2014-01-01

The calculation of heat-flow density in boreholes requires reliable values for the change of temperature and rock thermal conductivity with depth. As rock samples for laboratory measurements of thermal conductivity (TC) are usually rare geophysical well logs are used alternatively to determine TC...... parameters (i.e. thermal conductivity, density, hydrogen index, sonic interval transit time, gamma-ray response, photoelectric factor) of artificial mineral assemblages consisting 15 rock-forming minerals that are used in different combinations to typify sedimentary rocks. The predictive capacity of the new...... equations is evaluated on subsurface data from four boreholes drilled into the Mesozoic sequence of the North German Basin, including more than 1700 laboratory-measured thermal-conductivity values. Results are compared with those from other approaches published in the past. The new approach predicts TC...

Application of radiometric core data in developing correlation index for insitu gamma log and disequilibrium status across exploratory boreholes: a case study in Wahkut Block of West Khasi Hills District, Meghalaya, India

International Nuclear Information System (INIS)

Kukreti, B.M.; Kumar, Pramod

2011-01-01

With the objective to affirm apparent Uranium ore zone grade/thickness with good confidence for non-coring and coring boreholes with poor core recovery, a systematic study in the mineralised coring boreholes between insitu measured gamma ray log and laboratory measured core assay has been carried out, in the sedimentary environment of Wahkut block, West Khasi Hills district of Meghalaya. This also helps in quantifying correlation index and U disequilibrium status across the drilled boreholes and to convert apparent eU 3 O 8 grade to ore reserve (U 3 O 8 ). Study area consist of 2 sq km having 33 coring and 39 non coring boreholes with cumulative drilled depth of about 11,000 mts. On this available database, grade thickness continuity of uranium ore zone, in coring boreholes was evaluated with the criteria of minimal ore zone thickness of 1.0 mts at 100 ppm eU 3 O 8 cut-off grade. The same criteria were also extended to the core assay of drilled core. A population of 19 such simultaneous qualifying zone (borehole log and core assay) meeting the set criteria from 17 coring boreholes (average core recovery > 90%) was drawn. Study results gave grade thickness continuity index of 0.93 between radiometric core assay and borehole log with moderately strong relationship. Disequilibrium status of apparent eU 3 O 8 grade in the borehole was examined using chemically checked U 3 O 8 (β/γ) (Having high degree uranium data confidence 91%) and Ra (e) plot, after getting complete core samples radiometric and spectral gamma analysed for 14 such boreholes. Equilibrium status on this population indicates, disequilibrium in favour of parent (0.90-1.78 range) having log normal distribution and skewed to the higher side of mean 1.37 disequilibrium factor. (author)

In situ analysis of coal from single electrode resistance, self-potential and gamma-ray logs

International Nuclear Information System (INIS)

Kayal, J.R.

1981-01-01

Single electrode resistance, self-potential and gamma-ray logging have been carried out in North Karanpura, West Bokaro and Jharia coalfields of Gondwana basin in Eastern India. Correlation of these geophysical logs is found to be very useful in locating the coal beds, determining their accurate depths and thickness and approximate quality. Coal seams have been detected as very high resistive formations compared to sandstone/shale which are interbedded in the coal basin. High or low self-potential values are obtained against the coal beds depending on the borehole fluid conditions. Burnt coals (Jhama) are characterised as highly conductive beds. Gamma ray logs have been effectively used alongwith electrical logs for correlation and identification of coal seams. Further analysis of gamma-ray log data determines a linear relationship with ash content of coal. (author)

Uranium logging in earth formations

International Nuclear Information System (INIS)

Givens, W.W.

1979-01-01

A technique is provided for assaying the formations surrounding a borehole for uranium. A borehole logging tool cyclically irradiates the formations with neutrons and responds to neutron fluxes produced during the period of time that prompt neutrons are being produced by the neutron fission of uranium in the formations. A borehole calibration tool employs a steady-state (continuous output) neutron source, firstly, to produce a response to neutron fluxes in models having known concentrations of uranium and, secondly, to to produce a response to neutron fluxes in the formations surrounding the borehole. The neutron flux responses of the borehole calibration tool in both the model and the formations surrounding the borehole are utilized to correct the neutron flux response of the borehole logging tool for the effects of epithermal/thermal neutron moderation, scattering, and absorption within the borehole itself

Geostatistical analysis of the relationship between airborne electromagnetic data and borehole lithological data

DEFF Research Database (Denmark)

Barfod, Adrian; Møller, Ingelise; Christiansen, Anders Vest

2015-01-01

resistivity values, revealing different distribution functions for lithological categories. A very large and extensive dataset is available in Denmark through the national geophysical and borehole databases. These databases contain all geophysical and borehole data in Denmark and covers a large part of its......We present a large-scale study of the relationship between dense airborne SkyTEM resistivity data and sparse lithological borehole data. Airborne electromagnetic (AEM) data contains information about subsurface geology and hydrologic properties; however extracting this information is not trivial....... Today, geophysical data is used in combination with borehole data to create detailed geological models of the subsurface. The overall statistical relationship is, however, not widely known. The objective of this study is to develop a method for understanding the relationship between petrophysical...

Characterizing structures on borehole images and logging data of the Nankai trough accretionary prism: new insights

Science.gov (United States)

Jurado, Maria Jose

2016-04-01

IODP has extensively used the D/V Chikyu to drill the Kumano portion of the Nankai Trough, including two well sites within the Kumano Basin. IODP Expeditions 338 and 348 drilled deep into the inner accretionary prism south of the Kii Peninsula collecting a suite of LWD data, including natural gamma ray, electrical resistivity logs and borehole images, suitable to characterize structures (fractures and faults) inside the accretionary prism. Structural interpretation and analysis of logging-while-drilling data in the deep inner prism revealed intense deformation of a generally homogenous lithology characterized by bedding that dips steeply (60-90°) to the NW, intersected by faults and fractures. Multiple phases of deformation are characterized. IODP Expedition borehole images and LWD data acquired in the last decade in previous and results of NantroSEIZE IODP Expeditions (314, 319) were also analyzed to investigate the internal geometries and structures of the Nankai Trough accretionary prism. This study focused mainly on the characterization of the different types of structures and their specific position within the accretionary prism structures. New structural constraints and methodologies as well as a new approach to the characterization of study of active structures inside the prism will be presented.

Borehole imaging tool detects well bore fractures

International Nuclear Information System (INIS)

Ma, T.A.; Bigelow, E.L.

1993-01-01

This paper reports on borehole imaging data which can provide high quality geological and petrophysical information to improve fracture identification, dip computations, and lithology determinations in a well bore. The ability to visually quantify the area of a borehole wall occupied by fractures and vugs enhances reservoir characterization and well completion operations. The circumferential borehole imaging log (CBIL) instrument is an acoustic logging device designed to produce a map of the entire borehole wall. The visual images can confirm computed dips and the geological features related to dip. Borehole geometry, including breakout, are accurately described by complete circumferential caliper measurements, which is important information for drilling and completion engineers. In may reservoirs, the images can identify porosity type, bedding characteristics, and petrophysical parameters

Fractured-aquifer hydrogeology from geophysical logs; the passaic formation, New Jersey

Science.gov (United States)

Morin, R.H.; Carleton, G.B.; Poirier, S.

1997-01-01

The Passaic Formation consists of gradational sequences of mudstone, siltstone, and sandstone, and is a principal aquifer in central New Jersey. Ground-water flow is primarily controlled by fractures interspersed throughout these sedimentary rocks and characterizing these fractures in terms of type, orientation, spatial distribution, frequency, and transmissivity is fundamental towards understanding local fluid-transport processes. To obtain this information, a comprehensive suite of geophysical logs was collected in 10 wells roughly 46 m in depth and located within a .05 km2 area in Hopewell Township, New Jersey. A seemingly complex, heterogeneous network of fractures identified with an acoustic televiewer was statistically reduced to two principal subsets corresponding to two distinct fracture types: (1) bedding-plane partings and (2) high-angle fractures. Bedding-plane partings are the most numerous and have an average strike of N84??W and dip of 20??N. The high-angle fractures are oriented subparallel to these features, with an average strike of N79??E and dip of 71??S, making the two fracture types roughly orthogonal. Their intersections form linear features that also retain this approximately east-west strike. Inspection of fluid temperature and conductance logs in conjunction with flowmeter measurements obtained during pumping allows the transmissive fractures to be distinguished from the general fracture population. These results show that, within the resolution capabilities of the logging tools, approximately 51 (or 18 percent) of the 280 total fractures are water producing. The bedding-plane partings exhibit transmissivities that average roughly 5 m2/day and that generally diminish in magnitude and frequency with depth. The high-angle fractures have average transmissivities that are about half those of the bedding-plane partings and show no apparent dependence upon depth. The geophysical logging results allow us to infer a distinct hydrogeologic structure

Performance evaluation of groundwater model hydrostratigraphy from airborne electromagnetic data and lithological borehole logs

DEFF Research Database (Denmark)

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

2015-01-01

resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study. Benchmarking......Large-scale hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data alone. Due...... present a novel method to automatically integrate large AEM data sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models of electrical...

Development of a geophysical methodology from boreholes for the study of radioactive waste repositories in granit formations

International Nuclear Information System (INIS)

Le Masne, D.

1985-01-01

Within the frame of a 2-year contract with the C.E.C., dealing with storage and disposal of radioactive wastes in geological formations the B.R.G.M. has been involved in a research on the detection of fracturation from boreholes by geophysical methods. Various geometrical arrays (mono-hole, cross-hole, hole-to-surface) concerning mainly electrical methods, have been used in the field on granitic rocks, and interpreted according to three dimensional earth-models. Conductive or resistivite parallelepipedic inhomogeneities embedded in stratified or homogeneous half-spaces, have been taken into account in this three dimensional modelling. The influence of the various geometrical and electrical parameters of the inhomogeneities for different electrical arrays has been studied. Advantages and drawbacks of these arrays for the detection of the fracturation from boreholes, can be thus derived. An analysis of the calculation and drawing routines gives way to possible future improvements especially for modelling

Subsurface multidisciplinary research results at ICTJA-CSIC downhole lab and test site

Science.gov (United States)

Jurado, Maria Jose; Crespo, Jose; Salvany, Josep Maria; Teixidó, Teresa

2017-04-01

Two scientific boreholes, Almera-1 and Almera-2 were drilled in the Barcelona University campus area in 2011. The main purpose for this drilling was to create a new geophysical logging and downhole monitoring research facility and infrastructure. We present results obtained in the frame of multidisciplinary studies and experiments carried out since 2011 at the ICTJA "Borehole Geophysical Logging Lab - Scientific Boreholes Almera" downhole lab facilities. First results obtained from the scientific drilling, coring and logging allowed us to characterize the urban subsurface geology and hydrology adjacent to the Institute of Earth Sciences Jaume Almera (ICTJA-CSIC) in Barcelona. The subsurface geology and structural picture has been completed with recent geophysical studies and monitoring results. The upper section of Almera-1 214m deep hole was cased with PVC after drilling and after the logging operations. An open hole interval was left from 112m to TD (Paleozoic section). Almera-2 drilling reached 46m and was cased also with PVC to 44m. Since completion of the drilling in 2011, both Almera-1 and Almera-2 have been extensively used for research purposes, tests, training, hydrological and geophysical monitoring. A complete set of geophysical logging measurements and borehole oriented images were acquired in open hole mode of the entire Almera-1 section. Open hole measurements included acoustic and optical imaging, spectral natural gamma ray, full wave acoustic logging, magnetic susceptibility, hydrochemical-temperature logs and fluid sampling. Through casing (PVC casing) measurements included spectral gamma ray logging, full wave sonic and acoustic televiewer. A Quaternary to Paleozoic section was characterized based on the geophysical logging and borehole images interpretation and also on the complete set of (wireline) cores of the entire section. Sample availability was intended for geological macro and micro-facies detailed characterization, mineralogical and

A review of geophysical investigations at the site of Chalk River Nuclear Laboratories, Ontario

International Nuclear Information System (INIS)

Thomas, M.D.; Hayles, J.G.

1988-01-01

The site of the Chalk River Nuclear Laboratories was one of the first research areas located on crystalline rocks to be extensively investigated under the Canadian Nuclear Fuel Waste Management Program. A large contribution to meeting the geoscientific objectives of the program has been made using a suite of geophysical techniques. Many of them are standard, though sometimes modified in terms of instrumentation and/or experimental and/or analytical procedures, to meet the particular needs of the waste management program. Relatively new techniques have also been employed. Much of the early evaluation and development of the various techniques took place at the Chalk River site. Standard methods such as gravity, magnetics and seismic sounding have been used to investigate bedrock structure, and the seismic method has also been used to estimate overburden thickness. Standard geophysical borehole logging has been used to obtain in situ estimates of physical properties, to locate fracture zones and to make hole to hole correlations that have helped define local structure. Several standard electrical (e.g. resitivity) and electromagnetic (e.g. VLF-EM) techniques have proven successful in identifying water-filled fractures and faults. Relatively new techniques introduced into the geophysics at Chalk River were: ground probing radar; to investigate overburden; borehole TV and acoustic televiewer and VLF-EM, to locate fractures; studies of seismic tube-waves, well tides and temperature logs, to investigate fracture location and permeability. Most of these methods have been successful and are now routinely employed at other research sites

Evaluation of technology for large- and small-diameter boreholes to characterize crystalline rock

International Nuclear Information System (INIS)

1985-05-01

Testing methods that have been used in large- and small-diameter boreholes (152 and 76 mm [6 and 3 in.]) were evaluated on their ability to characterize crystalline rocks. The methods evaluated included in-hole geomechanical, geophysical, and geohydrologic techniques and associated laboratory core tests; specific emphasis was on techniques that might be used in a field characterization program involving a small number of deep (up to 1500 m [5000 ft]) boreholes. Each technique was evaluated with regard to its effectiveness and limitations, applicability to the acquisition of data for anticipated rock conditions, and adequacy for assessing the required rock/hydrologic characteristics. Many pertinent case histories that helped to assess applicability were reviewed. A principal objective of the evaluations was to assess whether the techniques would be equally useful in both large- and small-diameter boreholes. Of the techniques evaluated, most are suitable for use in both large- and small-diameter boreholes. Borehole logging, hydrologic testing, and core-testing techniques provide suitable results in both borehole diameters. Geomechanical testing techniques provide suitable data in smaller diameter boreholes and have been designed for application at primarily shallow depths. The results of this study will be of use to the Office of Crystalline Repository Development (OCRD) in determining to what degree it is appropriate to use drilling, sampling, and testing techniques in small-diameter boreholes as opposed to large-diameter methods, while at the same time collecting adequate data for characterizing crystalline rock environments for potential use as a high-level radioactive waste repository. Additionally, further developmental work and specific testing techniques are recommended

Preliminary evaluation of lithology and quality of coal and embedding rock on the basis of borehole logging data

International Nuclear Information System (INIS)

Nguyen Dinh Chau; Chrusciel, E.

1990-01-01

A simple computer method of interpretation of classic borehole logging made on coal deposits is presented. This interpretation enables fast determination of calorific value, ash content and moisture content of coal as well as shale content, porosity and sandstone matrix content of embedding rocks. A method of graphic representation of results is also shown. 5 figs., 1 tab., 13 refs. (author)

Difference flow measurements in borehole KOV01 at Oskarshamn

International Nuclear Information System (INIS)

Poellaenen, J.; Rouhiainen, P.

2001-09-01

Posiva Flow Log/Difference Flow method can be used for relatively fast determination of hydraulic conductivity and hydraulic head in fractures or fractured zones in cored boreholes. This report presents the principles of the method as well as the results of the measurements carried out in borehole KOV01 at Oskarshamn in February and March 2001. The aim of the measurements presented in this report was to determine the depth and flow rate of flowing fractures in borehole KOV01 prior to groundwater sampling. The measurements in borehole KOV01 were carried out between 100-1000 m depth using the so called detailed flow logging mode; the flow rate into a 5 m long test section was measured. Detailed flow logging was repeated at the location of the detected flow anomalies using 0.5 m section length and 0.1 m point intervals. The borehole was pumped during these measurements. The occurrence of saline water in the borehole was studied by electric conductivity measurements. The flow guide encloses also an electrode for measuring of single point resistance of the bedrock. It was measured with 0.01 m point intervals during the detailed flow logging. Depth calibration was made on the basis of the known depth marks in the borehole. The depth marks were detected by caliper measurements and by single point resistance measurements

Development of controlled drilling technology and measurement method in the borehole. Phase 2. Upgrading of drilling and measurement system and its application to the fault

International Nuclear Information System (INIS)

Kiho, Kenzo; Shin, Koichi; Ohtsu, Masashi

2009-01-01

In Japan, the soft sedimentary rock of the Neogene tertiary is being focused as a host rock for High Level Waste (HLW) disposal. Especially, the soft sedimentary rock at the coastal area is thought to be one of the best candidates, since there is little driving force of the underground water. The measurement and logging of the bore hole in order to investigate the hydro-geological and geo-mechanical conditions of the host rock is a very important way to examine the potential of the disposal candidates. Since 2000, CRIEPI (Central Research Institute of Electric Power Industry) has been conducting the project on controlled drilling and the logging/measurement technologies in its boreholes. Based on the results of phase 1(2000-2004), CRIEPI has been developing the drilling and logging/measurement technologies for fault zone during phase 2 (2005-2007). The drilling technology such as drilling for fault zone, horizontal drilling, long hole drilling, coring and locality detection was developed and these applicability was confirmed while drilling. The permeability/water-sampling/imaging tool was revised to apply wider borehole and longer measuring section. The WL-LWD was improved to be tougher in the hole. The borehole pressure meter and stress measurement tools were unified. Each tools necessary for the monitoring system is manufactured. The applicability of these tools and systems were verified in the borehole. After conducting surveys for the Omagari fault distributing at the Kami-horonobe area, the drilling site and borehole trace was decided in 2005. Considering the planned trace, the bore hole was drilled to the 683.5m long and its core recovery was 99.8%. Using borehole logging/measurement/survey, the geological, hydrological, geo-mechanical, geophysical and geochemical data were collected and the Omagari fault was characterized. (author)

Estimation of geothermal gradients from single temperature log-field cases

International Nuclear Information System (INIS)

Kutasov, I M; Eppelbaum, L V

2009-01-01

A geothermal gradient is one of the most frequently used parameters in logging geophysics. However, the drilling process greatly disturbs the temperature of the formations around the wellbore. For this reason, in order to determine with the required accuracy the formation temperatures and geothermal gradients, a certain length of shut-in time is required. It was shown earlier (Kutasov 1968 Freiberger Forshungshefte C 238 55–61, 1987 Geothermics 16 467–72) that at least two transient temperature surveys are needed to determine the geothermal gradient with adequate accuracy. However, in many cases only one temperature log is conducted in a shut-in borehole. For these cases, we propose an approximate method for the estimation of the geothermal gradient. The utilization of this method is demonstrated on four field examples

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

Science.gov (United States)

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

2008-01-01

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

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

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

2007-05-11

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

Geology of the Waste Treatment Plant Seismic Boreholes

Energy Technology Data Exchange (ETDEWEB)

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

2007-02-28

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

Joint Inversion of Geochemical Data and Geophysical Logs for Lithology Identification in CCSD Main Hole

Science.gov (United States)

Deng, Chengxiang; Pan, Heping; Luo, Miao

2017-12-01

The Chinese Continental Scientific Drilling (CCSD) main hole is located in the Sulu ultrahigh-pressure metamorphic (UHPM) belt, providing significant opportunities for studying the metamorphic strata structure, kinetics process and tectonic evolution. Lithology identification is the primary and crucial stage for above geoscientific researches. To release the burden of log analyst and improve the efficiency of lithology interpretation, many algorithms have been developed to automate the process of lithology prediction. While traditional statistical techniques, such as discriminant analysis and K-nearest neighbors classifier, are incompetent in extracting nonlinear features of metamorphic rocks from complex geophysical log data; artificial intelligence algorithms are capable of solving nonlinear problems, but most of the algorithms suffer from tuning parameters to be global optimum to establish model rather than local optimum, and also encounter challenges in making the balance between training accuracy and generalization ability. Optimization methods have been applied extensively in the inversion of reservoir parameters of sedimentary formations using well logs. However, it is difficult to obtain accurate solution from the logging response equations of optimization method because of the strong overlapping of nonstationary log signals when applied in metamorphic formations. As oxide contents of each kinds of metamorphic rocks are relatively less overlapping, this study explores an approach, set in a metamorphic formation model and using the Broyden Fletcher Goldfarb Shanno (BFGS) optimization algorithm to identify lithology from oxide data. We first incorporate 11 geophysical logs and lab-collected geochemical data of 47 core samples to construct oxide profile of CCSD main hole by using backwards stepwise multiple regression method, which eliminates irrelevant input logs step by step for higher statistical significance and accuracy. Then we establish oxide response

Summary of the Lavia borehole investications in 1984

International Nuclear Information System (INIS)

Aeikaes, T.; Oehberg, A.; Ryhaenen, V.

1985-02-01

Industrial Power Company Ltd (TVO) drilled in the spring 1984 a 1001 m deep borehole, diameter 56 mm, in Lavia. The borehole is used during the years 1984-85 for developing and testing research methods and equipment needed in site investigations of spent fuel final disposal in the future. In 1984 hydraulical and geophysical tests were made and groundwater samples were taken. The drilling site is a wide outcropped area in the northern part of the porphyritic granite formation of Lavia. Geological and fracture mapping as well as geophysical measurements on the surface were made in the area surrounding the drilling site. The bedrock consists of homonous porphyritic granite, in which quartzdiorite occurs in thin incalations. Magnetic or electric anomalies were not observed. Fracture frequency is low and the fractures appear mainly in two sets. The rock types vary in the borehole from porphyritic granite to diorite. Due to slight mineralogical variations, the diorite is either granodiorite, quartzdiorite or tonalite. Granite occurs as veins. Hydraulic conductivity was measured systematically with a packer separation of 30 m between the depths 73-973 m. Hydraulic conductivity is generally 10 -10 -10 -11 m/s. Electric, radiometric, magnetic and acoustic measurements were made in the borehole. In addition, the caliper and the temperature of the borehole were measured. The results of these geophysical measurements indicate the properties of rock types and fracturing in the borehole. On the basis of the results e.g. fracture porosity was interpreted. The results of acoustic tube wave measurement correlate well with hydraulic conductivity. Water samples were taken from four depths. The deepest level was 910 m. The samples were taken with a packer separation of 5 m. In the water analyses it was observed that at several depths remarkable amounts of flushing water from drilling were still remaining in the rock

A Proposed Borehole Scientific Laboratory in Quay County, New Mexico, USA

Science.gov (United States)

Nielson, Dennis; Eckels, Marc; Mast, Peter; Zellman, Mark; Creed, Robert

2017-04-01

Our team has received funding from the US Department of Energy to initiate a Deep Borehole Field Test that will develop a subsurface test site to evaluate the drilling and scientific aspects of deep borehole disposal of nuclear waste in crystalline rock. Phase 1 of the project will focus on Public Outreach and land acquisition whereas Phase 2 will generate a drilling and testing plan and secure regulatory approvals. Phase 3 will complete the Drilling and Testing Plan and Phase 4 will include the drilling and testing. Phase 5 will be devoted to borehole science and experiments with emplacement technology. Although we are specifically considering issues associated with the disposal of waste, this project is a proof of concept, and no waste will be emplaced at our site. In brief, the concept envisions an 8-1/2 inch open-hole completion at a depth of 5000 m in crystalline rock. There will be an extensive program of sample collection (including core) and analysis as well as geophysical logging and borehole testing. Critical issues will be low permeability in the crystalline rock as well as the ability to manage borehole quality. Our team has proposed a site in Quay County, New Mexico that has an 850 meter thick Paleozoic section overlying homogeneous Precambrian granite. A subsequent phase of the project may drill a second hole with a 17-1/2 inch completion located about 200 m from the first. Our long-term plan is that this site will be managed as a deep scientific observatory that also provides a facility for scientific experiments and testing of borehole infrastructure and drilling equipment.

Joint inversion of geophysical and hydrological data for improved subsurface characterization

International Nuclear Information System (INIS)

Kowalsky, Michael B.; Chen, Jinsong; Hubbard, Susan S.

2006-01-01

Understanding fluid distribution and movement in the subsurface is critical for a variety of subsurface applications, such as remediation of environmental contaminants, sequestration of nuclear waste and CO2, intrusion of saline water into fresh water aquifers, and the production of oil and gas. It is well recognized that characterizing the properties that control fluids in the subsurface with the accuracy and spatial coverage needed to parameterize flow and transport models is challenging using conventional borehole data alone. Integration of conventional borehole data with more spatially extensive geophysical data (obtained from the surface, between boreholes, and from surface to boreholes) shows promise for providing quantitative information about subsurface properties and processes. Typically, estimation of subsurface properties involves a two-step procedure in which geophysical data are first inverted and then integrated with direct measurements and petrophysical relationship information to estimate hydrological parameters. However, errors inherent to geophysical data acquisition and inversion approaches and errors associated with petrophysical relationships can decrease the value of geophysical data in the estimation procedure. In this paper, we illustrate using two examples how joint inversion approaches, or simultaneous inversion of geophysical and hydrological data, offer great potential for overcoming some of these limitations

NNWSI [Nevada Nuclear Waste Storage Investigations] hole history, UE-25p No. 1

International Nuclear Information System (INIS)

1986-11-01

This report is a compilation of data from one borehole drilled in Area 25 of the Nevada Test Site (NTS) under the guidance of the US Geological Survey. The borehole was drilled to obtain geologic, geophysical and hydrologic information. Data presented in this publication include location, daily activities, review of hole conditions, geophysical log listing, video tape listing, and microfiche copies of all geophysical logs run by the Fenix and Scisson subcontractors

A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

Energy Technology Data Exchange (ETDEWEB)

David Alumbaugh; Douglas LaBrecque; James Brainard; T.C. (Jim) Yeh

2004-01-22

The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation.

A Hydrologic-geophysical Method for Characterizing Flow and Transport Processes Within The Vadose Zone

International Nuclear Information System (INIS)

Alumbaugh, David; LaBrecque, Douglas; Brainard, James; Yeh, T.C.-Jim

2004-01-01

The primary purpose of this project was to employ two geophysical imaging techniques, electrical resistivity tomography and cross-borehole ground penetrating radar, to image a controlled infiltration of a saline tracer under unsaturated flow conditions. The geophysical techniques have been correlated to other more traditional hydrologic measurements including neutron moisture measurements and induction conductivity logs. Images that resulted during two successive infiltrations indicate the development of what appear to be preferential pathways through the finer grained materials, although the results could also be produced by cationic capture of free ions in clays. In addition the site as well as the developing solute plume exhibits electrical anisotropy which is likely related to flow properties. However the geologic significance of this phenomenon is still under investigation

SNG-logs at the Bagsvaerd Lake

International Nuclear Information System (INIS)

Korsbech, U.

1992-11-01

Spectral Natural Gamma-logs (SNG) were taken in old boreholes around Bagsvaerd Lake (Zealand). The purpose of this investigation was to clarify the geologic/lithologic conditions in this region and the potential risks of waste penetration into ground water. Relationship curves for thorium, uranium and potassium concentrations are given. Some special logs which can be useful for evaluating concentration variations or transition forms among various lithological layers are collected. Appendices contain technical information on the boreholes and discussion of differences between results of SNG-logging and the conventional gamma-logging. (EG)

Dependence of the neutron-gamma log on the porosity of Malmian limestones from the central part of the Nida Trough

International Nuclear Information System (INIS)

Szczerba, A.

1974-01-01

Results of correlation-regression analysis of the relationship of the prosity Kp to the relative intensity of neutron-induced gamma radiation dIng are reviewed. The geophysical results and laboratory tests of Malmian carbonate rocks from 10 boreholes from the central part of the Nida trough have been utilized to study this relationship. The regression equation dIng=∫(Kp) and the nomogram to determine the porosity Kp on the basis of neutron-gamma log or neutron-gamma and gamma logs, when the correction for the content is to be considered, have been also presented. (author)

The sonic borehole logging tool

International Nuclear Information System (INIS)

Oelgaard, P.L.

1990-09-01

This report deals with the sonic borehole tool. First a review of the various elastic wave types is given and velocity values of compressional waves in various materials listed. Next follows a discussion of 3 models for the relation between transit time and porosity, and a comparison between the 3 models is made. The design of sonic tools is described including their geometry. The path of the sonic signals is discussed. Also the effect of environmental factors on the results of the tools are considered. Finally a number of applications are described. In two appendices the mechanics of deformable bodies and formulas for the velocity of sound are reviewed. (author)

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

Science.gov (United States)

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

2016-12-01

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

Quantification of Wellbore Leakage Risk Using Non-destructive Borehole Logging Techniques

Energy Technology Data Exchange (ETDEWEB)

Duguid, Andrew; Butsch, Robert; Cary, J.; Celia, Michael; Chugunov, Nikita; Gasda, Sarah; Hovorka, Susan; Ramakrishnan, T. S.; Stamp, Vicki; Thingelstad, Rebecca; Wang, James

2014-08-29

Well integrity is important at all potential CCS locations and may play a crucial role establishing leakage risk in areas where there is a high density of existing wells that could be impacted by the storage operations including depleted petroleum fields where EOR or CCS will occur. To address a need for risk quantification methods that can be directly applied to individual wells using borehole logging tools a study was conducted using data from five wells in Wyoming. The objectives of the study were: Objective 1: Develop methods to establish the baseline flow parameters (porosity and permeability or mobility) from individual measurements of the material properties and defects in a well. Objective 2: Develop a correlation between field flow-property data and cement logs that can be used to establish the flow-properties of well materials and well features using cement mapping tools. Objective 3: Establish a method that uses the flow-property model (Objective 2) to analyze the statistical uncertainties associated with individual well leakage that can provide basis for uncertainty in risk calculations. The project objectives were met through the logging of five wells in Carbon and Natrona County Wyoming to collect data that was used to estimate individual and average well flow properties and model the results using ultrasonic data collected during the logging. Three of the five wells provided data on point and average flow properties for well annuli. Data from the other two wells were used to create models of cement permeability and test whether information collected in one well could be used to characterize another well. The results of the in-situ point measurements were confirmed by the lab measurements sidewall cores collected near the same depths Objective 1 was met using the data collected through logging, testing, and sampling. The methods were developed that can establish baseline flow parameters of wells by both point and average test methods. The methods to

Cavola experiment site: geophysical investigations and deployment of a dense seismic array on a landslide

Directory of Open Access Journals (Sweden)

L. Martelli

2007-06-01

Full Text Available Geophysical site investigations have been performed in association with deployment of a dense array of 95 3-component seismometers on the Cavola landslide in the Northern Apennines. The aim of the array is to study propagation of seismic waves in the heterogeneous medium through comparison of observation and modelling. The small-aperture array (130 m×56 m operated continuously for three months in 2004. Cavola landslide consists of a clay body sliding over mudstone-shale basement, and has a record of historical activity, including destruction of a small village in 1960. The site investigations include down-hole logging of P- and S-wave travel times at a new borehole drilled within the array, two seismic refraction lines with both P-wave profiling and surface-wave analyses, geo-electrical profiles and seismic noise measurements. From the different approaches a consistent picture of the depths and seismic velocities for the landslide has emerged. Their estimates agree with resonance frequencies of seismic noise, and also with the logged depths to basement of 25 m at a new borehole and of 44 m at a pre-existing borehole. Velocities for S waves increase with depth, from 230 m/s at the surface to 625 m/s in basement immediately below the landslide.

Site Characterization Of Borehole Disposal Facility (BOSS)

International Nuclear Information System (INIS)

Kamarudin Samuding; Mohd Abd Wahab Yusof; Mohd Muzamil; Nazran Harun; Nurul Fairuz Diyana Bahrudin; Ismail, C. Mohamad; Kalam

2014-01-01

Site characterization study is one of the major components in assessing the potential site for borehole disposal facility. The main objectives of this study are to obtain the geology, geomorphology, hydrogeology and geochemistry information in order to understand the regional geological setting, its past evolution and likely future natural evolution over the assessment time frame. This study was focused on the geological information, borehole log and hydrogeological information. Geological information involve general geology, lineament, topography, structure geology, geological terrain. Whereas Borehole log information consists of lithology, soil and rock formation, gamma logging data and physical properties of soil and rock. Hydrogeological information was emphasized on the groundwater flow, physical parameter as well as geochemical data. Geological mapping shows the study area is underlain by metamorphic rock of the Kenny Hill Formation. Lithologically, it composed of psammitic schist of sandstone origin and phyllite. Based on the borehole log profile, the study area is covered by thick layer of residual soil and estimated not less than 10 m. Those foliated rocks tend to break or split along the foliation planes. The foliation or schistosity may also serve as conduit for groundwater migration. Main structural geology features in the study area trend predominantly in North to Northeast directions. Major fault, the UKM Fault trends in NE-SW direction about 0.5 km located to the east of the proposed borehole site. The groundwater flow direction is influenced by the structure and bedding of the rock formation. Whereas the groundwater flow velocity in the borehole ranges 2.15 - 5.24 x 10 -4 m/ sec. All the data that are obtained in this study is used to support the Safety Assessment and Safety Case report. (author)

Basin Characterisation by Means of Joint Inversion of Electromagnetic Geophysical Data, Borehole Data and Multivariate Statistical Methods: The Loop Head Peninsula, Western Ireland, Case Study

Science.gov (United States)

Campanya, J. L.; Ogaya, X.; Jones, A. G.; Rath, V.; McConnell, B.; Haughton, P.; Prada, M.

2016-12-01

The Science Foundation Ireland funded project IRECCSEM project (www.ireccsem.ie) aims to evaluate Ireland's potential for onshore carbon sequestration in saline aquifers by integrating new electromagnetic geophysical data with existing geophysical and geological data. One of the objectives of this component of IRECCSEM is to characterise the subsurface beneath the Loop Head Peninsula (part of Clare Basin, Co. Clare, Ireland), and identify major electrical resistivity structures that can guide an interpretation of the carbon sequestration potential of this area. During the summer of 2014, a magnetotelluric (MT) survey was carried out on the Loop Head Peninsula, and data from a total of 140 sites were acquired, including audio-magnetotelluric (AMT), and broadband magnetotelluric (BBMT). The dataset was used to generate shallow three-dimensional (3-D) electrical resistivity models constraining the subsurface to depths of up to 3.5 km. The three-dimensional (3-D) joint inversions were performed using three different types of electromagnetic data: MT impedance tensor (Z), geomagnetic transfer functions (T), and inter-station horizontal magnetic transfer-functions (H). The interpretation of the results was complemented with second-derivative models of the resulting electrical resistivity models, and a quantitative comparison with borehole data using multivariate statistical methods. Second-derivative models were used to define the main interfaces between the geoelectrical structures, facilitating superior comparison with geological and seismic results, and also reducing the influence of the colour scale when interpreting the results. Specific analysis was performed to compare the extant borehole data with the electrical resistivity model, identifying those structures that are better characterised by the resistivity model. Finally, the electrical resistivity model was also used to propagate some of the physical properties measured in the borehole, when a good relation was

Cement thickness measurements in cased boreholes

International Nuclear Information System (INIS)

Wahl, J.S.; Schuster, N.A.

1978-01-01

Methods and apparatus are provided for logging a borehole having solid matter along at least a portion of the wall thereof. Gamma radiation is emitted from the borehole into the surrounding media, and the amount of radiation which returns to the borehole is measured by three detectors located at different distances from the source of radiation, so as to be primarily sensitive to radiation which has respectively penetrated to three different depths in the surrounding media. The thickness of the solid matter on the borehole wall is then determined from the three gamma radiation measurements

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

DEFF Research Database (Denmark)

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

2015-01-01

of electrical resistivity and clay fraction are classified into hydrostratigraphic zones using k-means clustering. Hydraulic conductivity values of the zones are estimated by hydrological calibration using hydraulic head and stream discharge observations. The method is applied to a Danish case study......Large-scale integrated hydrological models are important decision support tools in water resources management. The largest source of uncertainty in such models is the hydrostratigraphic model. Geometry and configuration of hydrogeological units are often poorly determined from hydrogeological data......-scale groundwater models. We present a novel method to automatically integrate large AEM data-sets and lithological information into large-scale hydrological models. Clay-fraction maps are produced by translating geophysical resistivity into clay-fraction values using lithological borehole information. Voxel models...

Protecting coastal abstraction boreholes from seawater intrusion using self-potential data

Science.gov (United States)

Graham, Malcolm; Butler, Adrian; MacAllister, Donald John; Vinogradov, Jan; Ijioma, Amadi; Jackson, Matthew

2016-04-01

We investigate whether the presence and transport of seawater can influence self-potentials (SPs) measured within coastal groundwater boreholes, with a view to using SP monitoring as part of an early warning system for saline intrusion. SP data were collected over a period of 18 months from a coastal groundwater borehole in the fractured Chalk of England. Spectral analysis of the results shows semi-diurnal fluctuations that are several orders of magnitude higher than those observed from monitoring of the Chalk more than 60 km inland, indicating a strong influence from oceanic tides. Hydrodynamic and geoelectric modelling of the coastal aquifer suggests that observed pressure changes (giving rise to the streaming potential) are not sufficient to explain the magnitude of the observed SP fluctuations. Simulation of the exclusion-diffusion potential, produced by changes in concentration across the saline front, is required to match the SP data from the borehole, despite the front being located some distance away. In late summer of 2013 and 2014, seawater intrusion occurred in the coastal monitoring borehole. When referenced to the shallowest borehole electrode, there was a characteristic increase in SP within the array, several days before any measurable increase in salinity. The size of this precursor increased steadily with depth, typically reaching values close to 0.3 mV in the deepest electrode. Numerical modelling suggests that the exclusion-diffusion potential can explain the magnitude of the precursor, but that the polarity of the change in SP cannot be replicated assuming a homogeneous aquifer. Small-scale models of idealised Chalk blocks were used to simulate the effects of discrete fractures on the distribution of SP. Initial results suggest that comparatively large reductions in voltage can develop in the matrix ahead of the front, in conjunction with a reduced or absent precursor in the vicinity of a fracture. Geophysical logging indicates the presence of a

Determination of barometric efficiency and effective porosity, boreholes UE-25 cNo.1, UE-25 cNo.2, UE-25 cNo.3, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Geldon, A.L.; Earle, J.D.; Umari, A.M.A.

1997-01-01

Simultaneous records of water-level altitudes in boreholes UE-25 cNo.1, UE-25 cNo.2, and UE-25 cNo.3 (the C-holes) and atmospheric pressure at and near the C-holes were obtained from July 15 to September 8, 1993, to determine the barometric efficiency of the entire uncased section of each of the C-holes, for the purpose of analyzing pumping tests. Each of the C-holes is 3,000 feet deep. About 1,600 feet of each borehole is open in Miocene tuffaceous rocks. Water-level altitudes in the C-holes fluctuate in response to Earth tides and changes in atmospheric pressure, which are characteristics of wells completed in an elastic, confined aquifer. The barometric efficiency of the C-holes in this study was analyzed by filtering simultaneously collected water-level-altitude and atmospheric-pressure data to remove the influences of Earth tides and semi-diurnal heating and cooling and then regressing filtered water-level-altitude changes as a function of filtered changes in atmospheric pressure. The average barometric efficiency of the uncased sections of boreholes UE-25 cNo.1 and UE-25 cNo.3 was determined to be 0.94. Malfunctioning equipment prevented determining the barometric efficiency of bore-hole UE-25 cNo.2. An average effective porosity of 0.36 was calculated from barometric efficiency values determined in this study and a specific storage value of 0.497 x 10 -6 per foot that was determined previously from geophysical logs of the C-holes. A porosity of 0.36 is consistent with values determined from geophysical logs and core analyses for the Calico Hills Formation

Study on the Geological Structure around KURT Using a Deep Borehole Investigation

International Nuclear Information System (INIS)

Park, Kyung Woo; Kim, Kyung Su; Koh, Yong Kwon; Choi, Jong Won

2010-01-01

To characterize geological features in study area for high-level radioactive waste disposal research, KAERI (Korea Atomic Energy Research Institute) has been performing the several geological investigations such as geophysical surveys and borehole drilling since 1997. Especially, the KURT (KAERI Underground Research Tunnel) constructed to understand the deep geological environments in 2006. Recently, the deep borehole of 500 m depths was drilled to confirm and validate the geological model at the left research module of the KURT. The objective of this research was to identify the geological structures around KURT using the data obtained from the deep borehole investigation. To achieve the purpose, several geological investigations such as geophysical and borehole fracture surveys were carried out simultaneously. As a result, 7 fracture zones were identified in deep borehole located in the KURT. As one of important parts of site characterization on KURT area, the results will be used to revise the geological model of the study area

Flow measurements in boreholes PHO1 and PHO2 in ONKALO

International Nuclear Information System (INIS)

Rouhiainen, P.; Pollanen, J.

2005-10-01

Posiva Flow Log/Difference Flow method can be used for relatively fast determination of hydraulic properties of fractures or fractured zones in boreholes. The flow sensor for flow along a borehole and a special flow guide are used for this measurement. This report presents the principles of the method as well as the results of the measurements carried out in the underground facilities of the ONKALO. Pilot boreholes PH01 and PH02 were measured. Borehole PH01 was measured on February 2004 and borehole PH02 on December 2004. Borehole PH01 was measured using 2 m section when it was in natural sate (without pumping it) and when water was pumped out from it. The upper part of the borehole was also measured when water was injected into the borehole. In addition to this, a detailed flow log was performed with 0.1 m point intervals using 0.5 m section length when water was pumped out from the borehole. Borehole PH02 was measured only with 0.5 m section length. The borehole was open during measurements and there was a natural outflow from the borehole during measurements. The flow guide encloses an electrode for single point resistance measurement, which was also carried out with 0.01 m point intervals during the flow measurements. Flow measurement and single point resistance measurement were used to locate flowing fractures and to evaluate their transmissivity. Electric conductivity (EC) and temperature of water was registered during flow logging. The conductivity values are temperature corrected to 25 deg C. (orig.)

Monitoring plan for borehole logging at 216-Z-1A Tile Field, 216-Z-9 Trench, and 216-Z-12 Crib

International Nuclear Information System (INIS)

Horton, D.G.

1998-04-01

This plan describes the fiscal year 1998 vadose monitoring of three inactive, liquid waste disposal facilities associated with the Plutonium Finishing Plant (Z-Plant): the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib. Monitoring will consist of spectral gamma ray logging of 21 boreholes. This plan describes the physical characteristics of the facilities, their operational histories, the subsurface geology and known contamination distribution at each facility. The plan then describes the specific monitoring to be done including the boreholes to be logged, the methods of data acquisition, data reduction, and data evaluation, and finally, the quality control, data management and data reporting for this effort. The three liquid waste disposal facilities at the Z Plant were chosen to be monitored because they were identified as containing some of the most significant sources of radioactive contamination in the Hanford vadose zone. Johnson's analysis was based on the relative hazard obtained by combining curie quantities disposed to the facilities with appropriate health risk standards. The basic question to be addressed by this logging activity addresses the configuration of subsurface contamination since it was last measured. Historical data from the 216-Z-1A Tile Field, the 216-Z-9 Trench, and the 216-Z-12 Crib form the baseline for comparisons to answer this question

Generating porosity spectrum of carbonate reservoirs using ultrasonic imaging log

Science.gov (United States)

Zhang, Jie; Nie, Xin; Xiao, Suyun; Zhang, Chong; Zhang, Chaomo; Zhang, Zhansong

2018-03-01

Imaging logging tools can provide us the borehole wall image. The micro-resistivity imaging logging has been used to obtain borehole porosity spectrum. However, the resistivity imaging logging cannot cover the whole borehole wall. In this paper, we propose a method to calculate the porosity spectrum using ultrasonic imaging logging data. Based on the amplitude attenuation equation, we analyze the factors affecting the propagation of wave in drilling fluid and formation and based on the bulk-volume rock model, Wyllie equation and Raymer equation, we establish various conversion models between the reflection coefficient β and porosity ϕ. Then we use the ultrasonic imaging logging and conventional wireline logging data to calculate the near-borehole formation porosity distribution spectrum. The porosity spectrum result obtained from ultrasonic imaging data is compared with the one from the micro-resistivity imaging data, and they turn out to be similar, but with discrepancy, which is caused by the borehole coverage and data input difference. We separate the porosity types by performing threshold value segmentation and generate porosity-depth distribution curves by counting with equal depth spacing on the porosity image. The practice result is good and reveals the efficiency of our method.

Subsurface Rock Physical Properties by Downhole Loggings - Case Studies of Continental Deep Drilling in Kanto Distinct, Japan

Science.gov (United States)

Omura, K.

2014-12-01

In recent years, many examples of physical logging have been carried out in deep boreholes. The loggings are direct in-situ measurements of rock physical properties under the ground. They provide significant basic data for the geological, geophysical and geotechnical investigations, e.g., tectonic history, seismic wave propagation, and ground motion prediction. Since about 1980's, Natl. Res. Inst. for Earth Sci. and Disast. Prev. (NIED) dug deep boreholes (from 200m to 3000m depth) in sedimentary basin of Kanto distinct, Japan, for purposes of installing seismographs and hydrological instruments, and in-situ stress and pore pressure measurements. At that time, downhole physical loggings were conducted in the boreholes: spontaneous potential, electrical resistance, elastic wave velocity, formation density, neutron porosity, total gamma ray, caliper, temperature loggings. In many cases, digital data values were provided every 2m or 1m or 0.1m. In other cases, we read printed graphs of logging plots and got digital data values. Data from about 30 boreholes are compiled. Especially, particular change of logging data at the depth of an interface between a shallow part (soft sedimentary rock) and a base rock (equivalent to hard pre-Neogene rock) is examined. In this presentation, the correlations among physical properties of rock (especially, formation density, elastic wave velocity and electrical resistance) are introduced and the relation to the lithology is discussed. Formation density, elastic wave velocity and electric resistance data indicate the data are divide in two groups that are higher or lower than 2.5g/cm3: the one correspond to a shallow part and the other correspond to a base rock part. In each group, the elastic wave velocity and electric resistance increase with increase of formation density. However the rates of increases in the shallow part are smaller than in the base rock part. The shallow part has lower degree of solidification and higher porosity

Multi-year monitoring of radon in boreholes at the Modra geophysical observatory, Slovakia

International Nuclear Information System (INIS)

Smetanova, I.; Steinitz, G.; Holy, K.

2017-01-01

Long-term radon monitoring was performed in two boreholes, at a depth of 13 m in the 40 m deep V-2 borehole (August 2003 September 2005), and at 3 m depth in the 10 m deep V-3 borehole (August 2003 April 2008). Diurnal, multi-day and annual variations in radon time-series were observed. Daily average of radon activity in V-2 borehole was significantly higher and ranged from 6.5 to 383.7 kBq/m 3 , while in V-3 borehole only between 1.2 and 139.4 kBq/m 3 . The seasonal pattern was more pronounced in V-3 time series, with the maximum occurring from October to March. Multi-day variations (2-10 days) were registered in V-2 and V-3 mostly simultaneously, with higher discrepancy in spring and summer periods, when radon activity in V-3 borehole was low. Diurnal radon variations with two maxima and two minima per day were registered in both boreholes. The influence of meteorological parameters on radon concentrations was investigated. The overall impression is that seasonal variation in radon in V-3 borehole seems to be connected with the temperature variation. Multi-day variations of radon in both boreholes coincided with the atmospheric pressure changes. An increase in radon activity was observed in V-3 borehole after the rainfall in spring and summer seasons. (authors)

Artificial Water Reservoir Triggered Earthquakes at Koyna, India: Completion of the 3 km deep Pilot Borehole

Science.gov (United States)

Gupta, H. K.; Tiwari, V. M.; Satyanarayana, H.; Roy, S.; Arora, K.; Patro, P. K.; Shashidhar, D.; Mallika, K.; Akkiraju, V.; Misra, S.; Goswami, D.; Podugu, N.; Mishra, S.

2017-12-01

Koyna, near the west coast of India is the most prominent site of artificial water reservoir triggered seismicity (RTS). Soon after the impoundment of the Koyna Dam in 1962, RTS was observed. It has continued till now. It includes the largest RTS earthquake M 6.3 on December 10, 1967; 22 M≥5.0, and thousands of smaller earthquakes. The entire earthquake activity is limited to an area of about 30 km x 20 km, with most focal depths being within 6 km. There is no other earthquake source within 50 km of the Koyna Dam. An ICDP Workshop held in March 2011 found Koyna to be the most suitable site to investigate reservoir- triggered seismicity (RTS) through deep drilling. Studies carried out in the preparatory phase since 2011 include airborne magnetic and gravity-gradient surveys, MT surveys, drilling of 9 boreholes going to depths of 1500 m and logging, heat flow measurements, seismological investigations including the deployment of six borehole seismometers, and LiDAR. The Second ICDP Workshop held during 16- 18 May 2014, reviewed the progress made and detailed planning of putting the borehole observatory was discussed. The site of a 3 km deep pilot borehole was debated and among the 5 possible location. Based on the seismic activity and logistics the location of the first Pilot Borehole has been finalized and the drilling started on the 21st December 2016. The 3000 m deep borehole was completed on 11th June 2017. The basement was touched at 1247 m depth and there were no sediments below basalt. Several zones with immense fluid losses were encountered. Geophysical Logging has been completed. Cores were recovered from 1269, 1892 and 2091 depths. The cores are 9 m long and with 4 inches diameter. The core recovery is almost 100%. In-situ stress measurements have been conducted at depths of 1600 m onwards.

Borehole logging for uranium exploration

International Nuclear Information System (INIS)

1982-01-01

The present text has been prepared taking into account the requirements of both developing countries, which might be at an incipient stage of uranium exploration, and industrialized countries, where more advanced exploration and resource evaluation techniques are commonly in use. While it was felt necessary to include some discussion of exploration concepts and fundamental physical principles underlying various logging methods, it was not the intention of the consultants to provide a thorough, detailed explanation of the various techniques, or even to give a comprehensive listing thereof. However, a list of references has been included, and it is strongly recommended that the serious student of mineral logging consult this list for further guidance

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

Science.gov (United States)

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).

Neutron--neutron logging

International Nuclear Information System (INIS)

Allen, L.S.

1977-01-01

A borehole logging tool includes a steady-state source of fast neutrons, two epithermal neutron detectors, and two thermal neutron detectors. A count rate meter is connected to each neutron detector. A first ratio detector provides an indication of the porosity of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two epithermal neutron detectors. A second ratio detector provides an indication of both porosity and macroscopic absorption cross section of the formation surrounding the borehole by determining the ratio of the outputs of the two count rate meters connected to the two thermal neutron detectors. By comparing the signals of the two ratio detectors, oil bearing zones and salt water bearing zones within the formation being logged can be distinguished and the amount of oil saturation can be determined. 6 claims, 2 figures

subsurface sequence delineation and saline water mapping of lagos

African Journals Online (AJOL)

A subsurface sequence delineation and saline water mapping of Lagos State was carried out. Ten (10) deep boreholes with average depth of 300 m were drilled within the sedimentary basin. The boreholes were lithologically and geophysically logged. The driller's lithological logs aided by gamma and resistivity logs, ...

Coal quality estimation using the geophysical logging of natural gamma and resistivity; Estimativa de qualidade de carvao por meio de perfilagem geofisica de gama natural e resistividade

Energy Technology Data Exchange (ETDEWEB)

Souza, Vladia de; Salvadoretti, Paulo; Costa, Joao Felipe Coimbra Leite; Beretta, Filipe; Koppe, Jair Carlos, E-mail: vladiasouza@gmail.co, E-mail: psalvadoretti@ufrgs.b, E-mail: jfelipe@ufrgs.b, E-mail: fberetta@ymail.co, E-mail: jkoppe@ufrgs.b [Universidade Federal do Rio Grande do Sul (UFRGS/LPM/DEMIN), Porto Alegre, RS (Brazil). Dept. de Engenharia de Minas. Lab. de Pesquisa Mineral e Planejamento Mineiro; Bastiani, Gustavo Antonio; Carvalho Junior, Jose Adolfo; Grigorieff, Alexandre, E-mail: gustavo.bastiani@terra.com.b, E-mail: adolfo@copelmi.com.b, E-mail: alex@copelmi.com.b [COPELMI Mineracao, Porto Alegre, RS (Brazil)

2010-10-15

This study investigates geophysical logging as a tool to predict coal quality. Some of the coal's chemical parameters were determined by laboratory analysis and were compared against values derived from geophysical logging correlation (natural gamma radiation and resistivity versus ash content, specifically). The results showed a strong correlation between the coal's natural gamma emissions and their ash content. From this correlation, a simple linear model was obtained and used to estimate ash grades, directly from geophysical logging records. The error of these predictions is less than {+-} 5%. Additionally, results showed no correlation between the sulphur grade, or volatile matter, and the geophysical records. Ash grades derived from natural gamma ray values can be used as secondary information to evaluate coal quality during resource estimation, when combined with lab analysis and appropriate geostatistical methods. The methodology is illustrated by means of a case study at a coal deposit located in Southern Brazil. (author)

Geophysical well-log measurements in three drill holes at Salt Valley, Utah

International Nuclear Information System (INIS)

Daniels, J.J.; Hite, R.J.; Scott, J.H.

1980-01-01

Three exploratory drill holes were drilled at Salt Valley, Utah, to study the geologic, physical, geochemical, and hydrologic properties of the evaporite sequence in the Permian Paradox Member of the Hermosa Formation. The results of these studies will be used to help to determine the suitability of salt deposits in the Paradox basin as a storage medium for radioactive waste material. The following geophysical well-log measurements were made in each of the three drill holes: (1) density, (2) neutron, (3) acoustic velocity, (4) normal resistivity, and (5) gamma ray. Widely spaced resistivity and conductivity well-log measurements were made in the deep drill hole. Each of these well-log measurements shows the division of the evaporite sequence into halite and interbed sections. At the present time the most useful well-logging measurements for determining the individual lithologies in an evaporite sequence are gamma ray, neutron, density, and acoustic velocity. The high resistivity contrast between the drilling fluid (0.5 ohm-m) and salt (10,000 ohm-m) makes it difficult to obtain quantitative measurements of electrical properties in an evaporite sequence. Tests of widely spaced electrode configurations show that the effects of the brine on the resistivity measurements can be reduced, and the depth of investigation increased, by increasing the source-receiver electrode spacing. Tests of a single-coil induction probe show good resolution of the contrasting electrical properties of the various interbed lithologies

Review of the Czubek--Jonas gamma-log program

International Nuclear Information System (INIS)

Matthews, M.

1978-11-01

Several gamma-ray logs were computer processed using the Czubek--Jones and DOE's MDDAT gamma-log programs. Both of these programs convert counts per second from the gamma-ray logs to percent eU 3 O 8 . The results of these programs were compared to each other and to the core analysis (percent U 3 O 8 ) of the logged boreholes. The two gamma-log programs produced similar results. The core analysis did not compare favorably with the results of either gamma-log program. This unfavorable comparison is probably due to an incorrect assumption of secular equilibrium for the ore surrounding the boreholes. The Czubek--Jonas program requires a knowledge of the linear attenuation coefficient of the rocks surrounding a borehole. This limits the usefulness of the program because this coefficient is generally not known and varies for different gamma-ray energies. It is recommended that the MDDAT program continue to be used for estimating the grade (percent eU 3 O 8 ) from gamma-log data and not be replaced by the Czubek--Jonas program

Detection of concrete dam leakage using an integrated geophysical technique based on flow-field fitting method

Science.gov (United States)

Dai, Qianwei; Lin, Fangpeng; Wang, Xiaoping; Feng, Deshan; Bayless, Richard C.

2017-05-01

An integrated geophysical investigation was performed at S dam located at Dadu basin in China to assess the condition of the dam curtain. The key methodology of the integrated technique used was flow-field fitting method, which allowed identification of the hydraulic connections between the dam foundation and surface water sources (upstream and downstream), and location of the anomalous leakage outlets in the dam foundation. Limitations of the flow-field fitting method were complemented with resistivity logging to identify the internal erosion which had not yet developed into seepage pathways. The results of the flow-field fitting method and resistivity logging were consistent when compared with data provided by seismic tomography, borehole television, water injection test, and rock quality designation.

Nuclear borehole probes - theory and experiments

International Nuclear Information System (INIS)

Joergensen, J.L.; Korsbech, U.; Gynther Nielsen, K.; Oelgaard, P.L.

1985-06-01

The report gives a summary of the theoretical and expeimental work on borehole probes that has been performed since 1971 at The Department of Electrophysics, The Technical University of Denmark. The first part of the report concerns the use of a spectral natural gamma-ray probe (SNG-probe), which is used for measurements of the spectral distribution of the gamma-rays of the geological strata around a borehole. In general the spectrum is divided into three parts - the gamma-rays from potassium-40, from thorium-232 and daughters, and from uranium-238 and daughters. A set of curves showing the intensities of the gamm-radiation from K, Th, and U versus depth is called a SNG-log. If proper calibrated, the SNG-log gives the concentration of Th, U, and K in the formation surrounding the borehole. Initially the basis for an interpretation of SNG-logs is discussed. Then follows a description og some SNG-problems designed and built by The Department of Electrophysics, and a discussion of the calibration of SNG-probes. Some examples of SNG-logs are presented, and some general comments on the use of SNG-logs are given. The second part of the report concerns mainly the development of theoretical models for neutron-neutron probes, gamma-gamma probes, and pulsed-neutron probes. The purpose of this work has been to examine how well the models correlate with measured results and - where reasonable agreement is found - to use the models in studies of the factors that affect the probe responses in interpretation of experimental results and in probe design. (author)

Application of an efficient materials perturbation technique to Monte Carlo photon transport calculations in borehole logging

International Nuclear Information System (INIS)

Picton, D.J.; Harris, R.G.; Randle, K.; Weaver, D.R.

1995-01-01

This paper describes a simple, accurate and efficient technique for the calculation of materials perturbation effects in Monte Carlo photon transport calculations. It is particularly suited to the application for which it was developed, namely the modelling of a dual detector density tool as used in borehole logging. However, the method would be appropriate to any photon transport calculation in the energy range 0.1 to 2 MeV, in which the predominant processes are Compton scattering and photoelectric absorption. The method enables a single set of particle histories to provide results for an array of configurations in which material densities or compositions vary. It can calculate the effects of small perturbations very accurately, but is by no means restricted to such cases. For the borehole logging application described here the method has been found to be efficient for a moderate range of variation in the bulk density (of the order of ±30% from a reference value) or even larger changes to a limited portion of the system (e.g. a low density mudcake of the order of a few tens of mm in thickness). The effective speed enhancement over an equivalent set of individual calculations is in the region of an order of magnitude or more. Examples of calculations on a dual detector density tool are given. It is demonstrated that the method predicts, to a high degree of accuracy, the variation of detector count rates with formation density, and that good results are also obtained for the effects of mudcake layers. An interesting feature of the results is that relative count rates (the ratios of count rates obtained with different configurations) can usually be determined more accurately than the absolute values of the count rates. (orig.)

Geological interpretation of borehole image and sonic logs. A case study from the North Sea

Energy Technology Data Exchange (ETDEWEB)

Vahle, C. [Eriksfiord GmbH, Walldorf (Germany)

2013-08-01

and a powerful, high-resolution data set spanning the scale from core to seismic. Resistivity variations of borehole images are on a considerably higher resolution compared to standard open-hole logs and connected to lithology and pore fluids. Hence high-resolution statistical evaluation of the image data enables thin-bed analysis or vuggy porosity calculations, which provide detailed N/G estimates. (orig.)

National logging program for the National Uranium Resource Evaluation. Final report

International Nuclear Information System (INIS)

The Mineral Engineering Division (MED) of High Life Helicopters, Inc., operated from May, 1979, through August, 1981, as a subcontractor to the Department of Energy (DOE) to acquire downhole geophysical log information in support of the National Uranium Resource Evaluation program (NURE). MED acquired downhole geophysical log information in 26 1 0 x 2 0 NTMS quadrangles in Colorado, Montana, Nebraska, North Dakota, South Dakota, and Wyoming. MED obtained the log information by gaining permission to log oil and gas wells, water wells, and coal exploration holes. Actual geophysical logging was subcontracted to Century Geophysical Corporation. After logging of each well and completed, MED submitted the log information and other pertinent data to Bendix Field Engineering Corporation (BFEC) for evaluation. MED collected over 700,000 feet of geophysical logs. Additionally, MED conducted a search of log libraries for existing log data for twelve of the quadrangles included in the program. It should be noted that ERTEC, Inc. conducted geophysical logging and a log library search to five quadrangles in Wyoming. These areas were later assigned to MED. The location of all wells logged by MED and ERTEC and the location of other log data is shown on the enclosed maps. Detailed information that pertains to each well is provided following each map

Uranium borehole logging using delayed or prompt fission neutrons

International Nuclear Information System (INIS)

Schulze, G.; Wuerz, H.

1977-04-01

The measurement of induced fission neutrons using Cf 252 and 14 MeV neutrons is a sensitive method for an in situ determination of Uranium. Applying this methods requires a unique relation between concentration of Uranium and intensity of induced fission neutrons. A discussion of parameters influencing the determination of concentration is given. A simple method is developed allowing an elemination of the geochemistry of the deposit and of the borehole configuration. Borehole probes using the methods described are of considerable help during the phase of detailed exploration of uranium ore deposits. These on-line tools allow an immediate determination of concentration. Thus avoiding the expensive and time consuming step of core drilling and subsequent chemical analysis. (orig./HP) [de

Simulation of wireline sonic logging measurements acquired with Borehole-Eccentered tools using a high-order adaptive finite-element method

KAUST Repository

Pardo, David

2011-07-01

The paper introduces a high-order, adaptive finite-element method for simulation of sonic measurements acquired with borehole-eccentered logging instruments. The resulting frequency-domain based algorithm combines a Fourier series expansion in one spatial dimension with a two-dimensional high-order adaptive finite-element method (FEM), and incorporates a perfectly matched layer (PML) for truncation of the computational domain. The simulation method was verified for various model problems, including a comparison to a semi-analytical solution developed specifically for this purpose. Numerical results indicate that for a wireline sonic tool operating in a fast formation, the main propagation modes are insensitive to the distance from the center of the tool to the center of the borehole (eccentricity distance). However, new flexural modes arise with an increase in eccentricity distance. In soft formations, we identify a new dipole tool mode which arises as a result of tool eccentricity. © 2011 Elsevier Inc.

Simulation of wireline sonic logging measurements acquired with Borehole-Eccentered tools using a high-order adaptive finite-element method

KAUST Repository

Pardo, David; Matuszyk, Paweł Jerzy; Muga, Ignacio; Torres-Verdí n, Carlos; Mora Cordova, Angel; Calo, Victor M.

2011-01-01

The paper introduces a high-order, adaptive finite-element method for simulation of sonic measurements acquired with borehole-eccentered logging instruments. The resulting frequency-domain based algorithm combines a Fourier series expansion in one spatial dimension with a two-dimensional high-order adaptive finite-element method (FEM), and incorporates a perfectly matched layer (PML) for truncation of the computational domain. The simulation method was verified for various model problems, including a comparison to a semi-analytical solution developed specifically for this purpose. Numerical results indicate that for a wireline sonic tool operating in a fast formation, the main propagation modes are insensitive to the distance from the center of the tool to the center of the borehole (eccentricity distance). However, new flexural modes arise with an increase in eccentricity distance. In soft formations, we identify a new dipole tool mode which arises as a result of tool eccentricity. © 2011 Elsevier Inc.

Multivariate and spatial statistical analysis of Callovo-Oxfordian physical properties from lab and borehole logs data: towards a characterization of lateral and vertical spatial trends in the Meuse/Haute-Marne transposition zone

International Nuclear Information System (INIS)

Garcia, M.H.; Rabaute, A.; Yven, B.; Guillemot, D.

2010-01-01

Document available in extended abstract form only. The geological exploration of the Meuse/Haute-Marne area began in 1994. Several boreholes were drilled, and the Callovo-Oxfordian argillite, thought to become a potential storage formation, were cored and logged. 2D and 3D seismic surveys were completed, as well as geological field observations, and an underground research laboratory was created. A 250 km 2 -wide Transposition Zone was delimited, which was subject to further investigations in 2007 and 2008, including another series of coring and logging in four additional boreholes, and a tighter 2D seismic survey. The main objective of this study was to improve the knowledge of the spatial variability of geological and physical properties of the Callovo-Oxfordian formation. The paper focuses on the three following aspects of the study to present and discuss the methods that have been used and the results that have been obtained: - Use of well-log data to identify equivalent homogeneous log-units on the boreholes. - Relating log attributes to physical properties of argillites measured on cores in laboratory. - Study of lateral and vertical spatial trends of selected physical properties across the Transposition Zone (TZ). To identify equivalent homogeneous log-units, a combination of Principal Component Analysis (PCA) and Fuzzy Cluster Analysis (FCA) was used. PCA was classically performed to reduce the number of variables to retain principal components gathering most of the original dataset variance. PCA was also used to identify isolated groups of correlated variables that could be associated to different properties of the formation. Then, FCA was applied to identify homogeneous log-units on the eight boreholes across the TZ. Well-logs data being much more numerous and better distributed along boreholes than lab data measured on rock samples, relations and correlations were sought between the two types of data to identify log attributes that were likely to provide

Deep Borehole Field Test Research Activities at LBNL

Energy Technology Data Exchange (ETDEWEB)

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

2016-08-19

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

Deep Borehole Field Test Research Activities at LBNL

International Nuclear Information System (INIS)

Dobson, Patrick; Tsang, Chin-Fu; Kneafsey, Timothy; Borglin, Sharon; Piceno, Yvette; Andersen, Gary; Nakagawa, Seiji; Nihei, Kurt; Rutqvist, Jonny; Doughty, Christine; Reagan, Matthew

2016-01-01

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

Lithology identification of aquifers from geophysical well logs and fuzzy logic analysis: Shui-Lin Area, Taiwan

Science.gov (United States)

Hsieh, Bieng-Zih; Lewis, Charles; Lin, Zsay-Shing

2005-04-01

The purpose of this study is to construct a fuzzy lithology system from well logs to identify formation lithology of a groundwater aquifer system in order to better apply conventional well logging interpretation in hydro-geologic studies because well log responses of aquifers are sometimes different from those of conventional oil and gas reservoirs. The input variables for this system are the gamma-ray log reading, the separation between the spherically focused resistivity and the deep very-enhanced resistivity curves, and the borehole compensated sonic log reading. The output variable is groundwater formation lithology. All linguistic variables are based on five linguistic terms with a trapezoidal membership function. In this study, 50 data sets are clustered into 40 training sets and 10 testing sets for constructing the fuzzy lithology system and validating the ability of system prediction, respectively. The rule-based database containing 12 fuzzy lithology rules is developed from the training data sets, and the rule strength is weighted. A Madani inference system and the bisector of area defuzzification method are used for fuzzy inference and defuzzification. The success of training performance and the prediction ability were both 90%, with the calculated correlation of training and testing equal to 0.925 and 0.928, respectively. Well logs and core data from a clastic aquifer (depths 100-198 m) in the Shui-Lin area of west-central Taiwan are used for testing the system's construction. Comparison of results from core analysis, well logging and the fuzzy lithology system indicates that even though the well logging method can easily define a permeable sand formation, distinguishing between silts and sands and determining grain size variation in sands is more subjective. These shortcomings can be improved by a fuzzy lithology system that is able to yield more objective decisions than some conventional methods of log interpretation.

Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Geldon, A.L.

1993-01-01

The purpose of this report is to characterize the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c No. 1, UE-25c No.2, and UE-25c No. 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys, aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes

Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Geldon, A.L.

1993-01-01

The purpose of this report is to characterize-the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c number-sign 1, UE-25c number-sign 2, and UE-25c number-sign 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes

Evaluation of permeable fractures in rock aquifers

Science.gov (United States)

Bok Lee, Hang

2015-04-01

In this study, the practical usefulness and fundamental applicability of a self-potential (SP) method for identifying the permeable fractures were evaluated by a comparison of SP methods with other geophysical logging methods and hydraulic tests. At a 10 m-shallow borehole in the study site, the candidates of permeable fractures crossing the borehole were first determined by conventional geophysical methods such as an acoustic borehole televiwer, temperature, electrical conductivity and gamma-gamma loggings, which was compared to the analysis by the SP method. Constant pressure injection and recovery tests were conducted for verification of the hydraulic properties of the fractures identified by various logging methods. The acoustic borehole televiwer and gamma-gamma loggings detected the open space or weathering zone within the borehole, but they cannot prove the possibility of a groundwater flow through the detected fractures. The temperature and electrical conductivity loggings had limitations to detect the fractured zones where groundwater in the borehole flows out to the surrounding rock aquifers. Comparison of results from different methods showed that there is a best correlation between the distribution of hydraulic conductivity and the variation of the SP signals, and the SP logging can estimate accurately the hydraulic activity as well as the location of permeable fractures. Based on the results, the SP method is recommended for determining the hydraulically-active fractures rather than other conventional geophysical loggings. This self-potential method can be effectively applied in the initial stage of a site investigation which selects the optimal location and evaluates the hydrogeological property of fractures in target sites for the underground structure including the geothermal reservoir and radioactive waste disposal.

Working program for deep borehole investigations. HDB-6,7,8, borehole

International Nuclear Information System (INIS)

Hama, Katsuhiro; Takahashi, Kazuharu; Ishii, Eiichi; Takeuchi, Ryuji; Sasaki, Manabu; Kunimaru, Takanori; Eki, Nobuhiro; Matsui, Hiroya

2003-08-01

In the Horonobe Underground Research Laboratory project, a wide range of geoscientific research and development activities are planned to be performed in three phases, Surface-based Investigations (Phase I), Construction (Phase II) and Operations (Phase III), over period of 20 years. Surface-based investigations have been conducted since 2000. Main goals of the Horonobe project are; To establish comprehensive techniques for investigating the geological environment, and To develop a range of engineering techniques for deep underground applications. The specific goals of the surface-based investigations are, To construct geological models of the geological environment based on the surface-based investigations and develop an understanding of the deep geological environment (undisturbed, initial conditions) before excavation of the shaft and experimental drifts To formulate detailed design and plans for the construction of the shaft and experimental drifts, and To plan scientific investigations during the construction phase. Field investigations during the surface-based investigations phase are planned for completion by the end of 2005, with excavation of the main shaft, Phase 2 construction, planned to start in 2005. The diameter of the main shafts has provisionally been set at 6.5 meters and the proposed depth is 500 meters. Details of the geometry and depth of specific underground facilities, including the main shaft, the ventilation shaft and the drifts, will be defined using data on the geological environment obtained during the surface-based investigation phase. As part of the surface-based investigations, geological, geophysical, hydrogeological, hydrochemical and rock mechanical investigations were carried out. Deep borehole investigations started in 2000 in order to characterize the sedimentary rocks. Taking into account the status of the investigations as of April 2003 and the remaining time (i.e., three year) for the surface-based investigations, an

Inferring the lithology of borehole rocks by applying neural network classifiers to downhole logs: an example from the Ocean Drilling Program

Science.gov (United States)

Benaouda, D.; Wadge, G.; Whitmarsh, R. B.; Rothwell, R. G.; MacLeod, C.

1999-02-01

In boreholes with partial or no core recovery, interpretations of lithology in the remainder of the hole are routinely attempted using data from downhole geophysical sensors. We present a practical neural net-based technique that greatly enhances lithological interpretation in holes with partial core recovery by using downhole data to train classifiers to give a global classification scheme for those parts of the borehole for which no core was retrieved. We describe the system and its underlying methods of data exploration, selection and classification, and present a typical example of the system in use. Although the technique is equally applicable to oil industry boreholes, we apply it here to an Ocean Drilling Program (ODP) borehole (Hole 792E, Izu-Bonin forearc, a mixture of volcaniclastic sandstones, conglomerates and claystones). The quantitative benefits of quality-control measures and different subsampling strategies are shown. Direct comparisons between a number of discriminant analysis methods and the use of neural networks with back-propagation of error are presented. The neural networks perform better than the discriminant analysis techniques both in terms of performance rates with test data sets (2-3 per cent better) and in qualitative correlation with non-depth-matched core. We illustrate with the Hole 792E data how vital it is to have a system that permits the number and membership of training classes to be changed as analysis proceeds. The initial classification for Hole 792E evolved from a five-class to a three-class and then to a four-class scheme with resultant classification performance rates for the back-propagation neural network method of 83, 84 and 93 per cent respectively.

The boreholes and geology of the Down Ampney fault research site

International Nuclear Information System (INIS)

Brightman, M.A.; Hallam, J.R.; Ambrose, K.; Horton, A.

1991-01-01

An exploratory programme of core drilling confirmed the location of a major fault with a 50-m throw and 70 0 dip and provided geological reference sections. These data enabled a measurement array of boreholes to be planned and constructed for the geophysical and hydrogeological characterization of the fault. Full details are given of the design, drilling, coring, completion and surveying of the 22 boreholes. The geological sequence is described, together with the structure of the fault zone, which was penetrated by eight boreholes

What's down below? Current and potential future applications of geophysical techniques to identify subsurface permafrost conditions (Invited)

Science.gov (United States)

Douglas, T. A.; Bjella, K.; Campbell, S. W.

2013-12-01

For infrastructure design, operations, and maintenance requirements in the North the ability to accurately and efficiently detect the presence (or absence) of ground ice in permafrost terrains is a serious challenge. Ground ice features including ice wedges, thermokarst cave-ice, and segregation ice are present in a variety of spatial scales and patterns. Currently, most engineering applications use borehole logging and sampling to extrapolate conditions at the point scale. However, there is high risk of over or under estimating the presence of frozen or unfrozen features when relying on borehole information alone. In addition, boreholes are costly, especially for planning linear structures like roads or runways. Predicted climate warming will provide further challenges for infrastructure development and transportation operations where permafrost degradation occurs. Accurately identifying the subsurface character in permafrost terrains will allow engineers and planners to cost effectively create novel infrastructure designs to withstand the changing environment. There is thus a great need for a low cost rapidly deployable, spatially extensive means of 'measuring' subsurface conditions. Geophysical measurements, both terrestrial and airborne, have strong potential to revolutionize our way of mapping subsurface conditions. Many studies in continuous and discontinuous permafrost have used geophysical measurements to identify discrete features and repeatable patterns in the subsurface. The most common measurements include galvanic and capacitive coupled resistivity, ground penetrating radar, and multi frequency electromagnetic induction techniques. Each of these measurements has strengths, weaknesses, and limitations. By combining horizontal geophysical measurements, downhole geophysics, multispectral remote sensing images, LiDAR measurements, and soil and vegetation mapping we can start to assemble a holistic view of how surface conditions and standoff measurements

High-Resolution Wellbore Temperature Logging Combined with a Borehole-Scale Heat Budget: Conceptual and Analytical Approaches to Characterize Hydraulically Active Fractures and Groundwater Origin

Directory of Open Access Journals (Sweden)

Guillaume Meyzonnat

2018-01-01

Full Text Available This work aims to provide an overview of the thermal processes that shape wellbore temperature profiles under static and dynamic conditions. Understanding of the respective influences of advection and conduction heat fluxes is improved through the use of a new heat budget at the borehole scale. Keeping in mind the thermal processes involved, a qualitative interpretation of the temperature profiles allows the occurrence, the position, and the origin of groundwater flowing into wellbores from hydraulically active fractures to be constrained. With the use of a heat budget developed at the borehole scale, temperature logging efficiency has been quantitatively enhanced and allows inflow temperatures to be calculated through the simultaneous use of a flowmeter. Under certain hydraulic or pumping conditions, both inflow intensities and associated temperatures can also be directly modelled from temperature data and the use of the heat budget. Theoretical and applied examples of the heat budget application are provided. Applied examples are shown using high-resolution temperature logging, spinner flow metering, and televiewing for three wells installed in fractured bedrock aquifers in the St-Lawrence Lowlands, Quebec, Canada. Through relatively rapid manipulations, thermal measurements in such cases can be used to detect the intervals or discrete positions of hydraulically active fractures in wellbores, as well as the existence of ambient flows with a high degree of sensitivity, even at very low flows. Heat budget calculations at the borehole scale during pumping indicate that heat advection fluxes rapidly dominate over heat conduction fluxes with the borehole wall. The full characterization of inflow intensities provides information about the distribution of hydraulic properties with depth. The full knowledge of inflow temperatures indicates horizons that are drained from within the aquifer, providing advantageous information on the depth from which

Optimisation of borehole logs in highly inclined natural gas boreholes in the new red sandstone strata of northern Germany - examples of the use of modern LWD technology; Optimierung von Bohrlochmessungen in hochgeneigten Erdgasbohrungen des norddeutschen Rotliegend - Beispiele zum Einsatz moderner LWD Technologie

Energy Technology Data Exchange (ETDEWEB)

Tappe, G.; Riepe, L. [BEB Erdgas und Erdoel GmbH, Hannover (Germany)

2001-07-01

Data acquisition and interpretation of LWD logs (''logging while drilling'') in highly inclined boreholes in new red sandstone have proved this to be a reliable alternative to conventional wireline measurements in assessing porosity and saturation. The contribution presents the results of the first measurements made in Germany using this method, which are compared with conventional wireline logs and drill core data. The LWD technology is superior in difficult boreholes and less costly if no conventional logs are made. Another advantage is the fact that the deposit is analyzed in the ''virgin'' state, i.e. before deep invasion by drilling, flushing and other invasive operations. [German] Die Datenakquisition und Interpretation von LWD (''logging while drilling'')-Messungen in hochgeneigten Rotliegend-Bohrungen haben gezeigt, dass es sich hierbei um eine zuverlaessige Alternative zu konventionellen Wireline-Messungen hinsichtlich der Porositaets- und Saettigungsbestimmung handelt. In diesem Beitrag werden insbesondere die Ergebnisse der ersten in Deutschland erfolgreich durchgefuehrten Messungen mit dem Sonic-LWD in tiefen 5 7/8{sup ''} Bohrloechern dargestellt und mit konventionellen Wireline-Logs und Kerndaten verglichen. Die operationellen Vorteile des LWD gerade in bohrtechnisch schwierigen Bohrungen wurden in der Praxis bestaetigt; Kostenvorteile sind vor allem dann gegeben, wenn auf konventionelles Loggen verzichtet wird. Ein weiterer Vorteil der echten ''Real Time''-LWD-Messungen ist zudem die Erfassung der petrophysikalischen Messungen im nahezu ''jungfraeulichen'' Zustand der Lagerstaette, d.h. bevor durch tiefe Invasion von Bohrspuelung und andere Traegerschaedigungen die Ergebnisse verfaelscht werden koennen. (orig.)

Preliminary analysis of geophysical logs from drill hole UE-25p No. 1, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

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

1984-01-01

Geophysical logs from drill hole UE-25p No. 1 correlate well with logs through the same geologic units from other drill holes at Yucca Mountain, Nevada. The in-situ physical properties of the rocks as determined from well logs are consistent with laboratory-measured physical properties of core from other drill holes. The density, neutron and caliper logs are very spiky through most of the Topopah Spring Member. This spikiness occurs on the same logs in cored holes where the Topopah Spring Member is highly fractured and lithophysal. The uranium channel of the spectral gamma-ray log through the Topopah Spring Member correlates with uranium logs from cored holes where most of the fractures have not been healed or filled with materials that concentrate uranium. Therefore, fracture porosity and permeability of the Topopah Spring Member are expected to be high and consistent with fracture analysis from other drill holes on Yucca Mountain, and hydrologic tests from well J-13. The Paleozoic dolomites which underlie the Tertiary tuffs are intensely brecciated, and the uranium count rate is much higher than normal for dolomites because uranium has been concentrated in the recementing material. 19 references, 1 figure, 2 tables

Background subtraction system for pulsed neutron logging of earth boreholes

International Nuclear Information System (INIS)

Hertzog, R.C.

1983-01-01

The invention provides a method for determining the characteristics of earth formations surrounding a well borehole comprising the steps of: repetitively irradiating the earth formations surrounding the well bore with relatively short duration pulses of high energy neutrons; detecting during each pulse of high energy neutrons, gamma radiation due to the inelastic scattering of neutrons by materials comprising the earth formations surrounding the borehole and providing information representative thereof; detecting immediately following each such pulse of high energy neutrons, background gamma radiation due to thermal neutron capture and providing information representative thereof; and correcting the inelastic gamma representative information to compensate for said background representative information

Mapping deep aquifer salinity trends in the southern San Joaquin Valley using borehole geophysical data constrained by chemical analyses

Science.gov (United States)

Gillespie, J.; Shimabukuro, D.; Stephens, M.; Chang, W. H.; Ball, L. B.; Everett, R.; Metzger, L.; Landon, M. K.

2016-12-01

The California State Water Resources Control Board and the California Division of Oil, Gas and Geothermal Resources are collaborating with the U.S. Geological Survey to map groundwater resources near oil fields and to assess potential interactions between oil and gas development and groundwater resources. Groundwater resources having salinity less than 10,000 mg/L total dissolved solids may be classified as Underground Sources of Drinking Water (USDW) and subject to protection under the federal Safe Drinking Water Act. In this study, we use information from oil well borehole geophysical logs, oilfield produced water and groundwater chemistry data, and three-dimensional geologic surfaces to map the spatial distribution of salinity in aquifers near oil fields. Salinity in the southern San Joaquin Valley is controlled primarily by depth and location. The base of protected waters occurs at very shallow depths, often 1,500 meters, in the eastern part of the San Joaquin Valley where higher runoff from the western slopes of the Sierra Nevada provide relatively abundant aquifer recharge. Stratigraphy acts as a secondary control on salinity within these broader areas. Formations deposited in non-marine environments are generally fresher than marine deposits. Layers isolated vertically between confining beds and cut off from recharge sources may be more saline than underlying aquifers that outcrop in upland areas on the edge of the valley with more direct connection to regional recharge areas. The role of faulting is more ambiguous. In some areas, abrupt changes in salinity may be fault controlled but, more commonly, the faults serve as traps separating oil-bearing strata that are exempt from USDW regulations, from water-bearing strata that are not exempt.

Alligator Rivers Analogue project. Geophysics, petrophysics and structure

International Nuclear Information System (INIS)

Emerson, D.W.; Mills, K.J.; Hallett, M.S.; Cao, L.Q.; Miyakawa, K.

1992-01-01

The geophysical and geological field work at Koongarra (including borehole core logging) showed that the site itself is a folded, faulted, variably fractured Precambrian psammitic and pelitic schist sequence with a quasi-horizontal weathered zone superimposed on the steeply dipping rock fabric. The site is flanked by a high resistivity younger sandstone unit to the northwest and by a magnetic amphibolite/ferricrete sequence to the far southeast. The data interpretations elicited the essential structural and broad lithological elements. Gravity, magnetic and electrical laboratory and field studies confirmed a broad folded fractured sequence of dipping layered host rocks weathered in their upper parts and trending in a southwest-northeast direction. Qualitatively interpreted anomalies indicated the trend of the main groundwater movement to the south where dolomites are thought to act as a sink. These drainage features have SP, resistivity and radiometric expression. The roles of the Kombolgie Sandstone as a source of water and the Koongarra Fault as a barrier or otherwise were not established owing to the lack of sufficient samples for testing and also on account of the difficulty of geophysical access over the site's rugged escarpment. 40 refs., 13 tabs., 69 figs

Joint Inversion Modelling of Geophysical Data From Lough Neagh Basin

Science.gov (United States)

Vozar, J.; Moorkamp, M.; Jones, A. G.; Rath, V.; Muller, M. R.

2015-12-01

Multi-dimensional modelling of geophysical data collected in the Lough Neagh Basin is presented in the frame of the IRETHERM project. The Permo-Triassic Lough Neagh Basin, situated in the southeastern part of Northern Ireland, exhibits elevated geothermal gradient (~30 °C/km) in the exploratory drilled boreholes. This is taken to indicate good geothermal exploitation potential in the Sherwood Sandstone aquifer for heating, and possibly even electricity production, purposes. We have used a 3-D joint inversion framework for modelling the magnetotelluric (MT) and gravity data collected to the north of the Lough Neagh to derive robust subsurface geological models. Comprehensive supporting geophysical and geological data (e.g. borehole logs and reflection seismic images) have been used in order to analyze and model the MT and gravity data. The geophysical data sets were provided by the Geological Survey of Northern Ireland (GSNI). Considering correct objective function weighting in favor of noise-free MT response functions is particularly important in joint inversion. There is no simple way how to correct distortion effects the 3-D responses as can be done in 1-D or 2-D case. We have used the Tellus Project airborne EM data to constrain magnetotelluric data and correct them for near surface effects. The shallow models from airborne data are used to constrain the uppermost part of 3-D inversion model. Preliminary 3-D joint inversion modeling reveals that the Sherwood Sandstone Group and the Permian Sandstone Formation are imaged as a conductive zone at the depth range of 500 m to 2000 m with laterally varying thickness, depth, and conductance. The conductive target sediments become shallower and thinner to the north and they are laterally continuous. To obtain better characterization of thermal transport properties of investigated area we used porosity and resistivity data from the Annaghmore and Ballymacilroy boreholes to estimate the relations between porosity

Bhtv looks right down the borehole

Energy Technology Data Exchange (ETDEWEB)

1969-04-01

A borehole televiewer uses acoustic pulses to produce a camera-like picture of downhole conditions. A block diagram shows the borehole televiewer logging system. The diameter of the tool is 3-3/8 in., but slimmer tools can be built. The nominal logging speed is 15 ft per min. Vertical fractures will show on the log as double vertical lines, horizontal fractures as single horizontal lines, and dipping fractures as curves that are roughly symmetrical. The orientation of the minimum of the curve is the dip direction of the fracture. The original idea was to find a tool to give guidance in fracturing jobs, and so far the tool has been primarily used for that purpose. It will also be a tremendous help for geologists and engineers on wildcate wells who have to make the agonizing decision to complete or abandon. It will show fracture porosity that no other currently available tool will show. It also will be a very useful supplement for the dipmeter. It can accurately locate vugs and washouts, and show changes in porosity and lithology. Mobil Oil is now using the tool as a standard log on all its wildcat wells.

Digital mineral logging system

International Nuclear Information System (INIS)

West, J.B.

1980-01-01

A digital mineral logging system acquires data from a mineral logging tool passing through a borehole and transmits the data uphole to an electronic digital signal processor. A predetermined combination of sensors, including a deviometer, is located in a logging tool for the acquisition of the desired data as the logging tool is raised from the borehole. Sensor data in analog format is converted in the logging tool to a digital format and periodically batch transmitted to the surface at a predetermined sampling rate. An identification code is provided for each mineral logging tool, and the code is transmitted to the surface along with the sensor data. The self-identifying tool code is transmitted to the digital signal processor to identify the code against a stored list of the range of numbers assigned to that type of tool. The data is transmitted up the d-c power lines of the tool by a frequency shift key transmission technique. At the surface, a frequency shift key demodulation unit transmits the decoupled data to an asynchronous receiver interfaced to the electronic digital signal processor. During a recording phase, the signals from the logging tool are read by the electronic digital signal processor and stored for later processing. During a calculating phase, the stored data is processed by the digital signal processor and the results are outputted to a printer or plotter, or both

Fracture Modes and Identification of Fault Zones in Wenchuan Earthquake Fault Scientific Drilling Boreholes

Science.gov (United States)

Deng, C.; Pan, H.; Zhao, P.; Qin, R.; Peng, L.

2017-12-01

After suffering from the disaster of Wenchuan earthquake on May 12th, 2008, scientists are eager to figure out the structure of formation, the geodynamic processes of faults and the mechanism of earthquake in Wenchuan by drilling five holes into the Yingxiu-Beichuan fault zone and Anxian-Guanxian fault zone. Fractures identification and in-situ stress determination can provide abundant information for formation evaluation and earthquake study. This study describe all the fracture modes in the five boreholes on the basis of cores and image logs, and summarize the response characteristics of fractures in conventional logs. The results indicate that the WFSD boreholes encounter enormous fractures, including natural fractures and induced fractures, and high dip-angle conductive fractures are the most common fractures. The maximum horizontal stress trends along the borehole are deduced as NWW-SEE according to orientations of borehole breakouts and drilling-induced fractures, which is nearly parallel to the strikes of the younger natural fracture sets. Minor positive deviations of AC (acoustic log) and negative deviation of DEN (density log) demonstrate their responses to fracture, followed by CNL (neutron log), resistivity logs and GR (gamma ray log) at different extent of intensity. Besides, considering the fact that the reliable methods for identifying fracture zone, like seismic, core recovery and image logs, can often be hampered by their high cost and limited application, this study propose a method by using conventional logs, which are low-cost and available in even old wells. We employ wavelet decomposition to extract the high frequency information of conventional logs and reconstruction a new log in special format of enhance fracture responses and eliminate nonfracture influence. Results reveal that the new log shows obvious deviations in fault zones, which confirm the potential of conventional logs in fracture zone identification.

Encyclopedia of well logging

International Nuclear Information System (INIS)

Desbrandes, R.

1985-01-01

The 16 chapters of this book aim to provide students, trainees and engineers with a manual covering all well-logging measurements ranging from drilling to productions, from oil to minerals going by way of geothermal energy. Each chapter is a summary but a bibliography is given at the end of each chapter. Well-logging during drilling, wireline logging equipment and techniques, petroleum logging, data processing of borehole data, interpretation of well-logging, sampling tools, completion and production logging, logging in relief wells to kill off uncontrolled blowouts, techniques for high temperature geothermal energy, small-scale mining and hydrology, logging with oil-base mud and finally recommended logging programs are all topics covered. There is one chapter on nuclear well-logging which is indexed separately. (UK)

Geophysical investigations in the Syyry area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Kurimo, M.

1992-12-01

Investigations were carried out at the Syyry site at Sievi using geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Geophysical investigations in the Olkiluoto area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Paananen, M.

1992-12-01

Investigations were carried out at the Olkiluoto site at Eurajoki using geological, geophysical, geohydrological and geochemical methods in 1987-1992 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. In this survey airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Geophysical investigations in the Kivetty area, Finland

International Nuclear Information System (INIS)

Heikkinen, E.; Paananen, M.; Oehberg, A.; Front, K.; Okko, O.; Pitkaenen, P.

1992-09-01

Investigations were carried out at Kivetty site in Konginkangas, in central Finland, by geological, geophysical, geohydrological and geochemical methods in 1987-1991 to determine the suitability of the bedrock for the final disposal of spent nuclear fuel. Airborne, ground and borehole geophysical methods were used to study the rock type distribution, fracturing and hydraulic conductivity of the bedrock to a depth of one kilometre

Neutron capture in borehole logging

International Nuclear Information System (INIS)

Randall, R.R.

1981-01-01

The use is described of a pulsed source of fast neutrons and a radiation detector to measure the thermal neutron population decay rate in a well logging instrument. The macroscopic neutron absorption cross-section is calculated by taking the natural logarithm of the ratio of the detected radiation counts occurring within two measurement intervals of fixed duration and starting at a fixed time after a neutron burst. (U.K.)

Nuclear log interpretation by first principle

International Nuclear Information System (INIS)

Oelgaard, P.L.

1988-07-01

A weakness connected to the present interpretation of nuclear borehole logs is that the interdependence of the various logs and physical effects of importance for the tools are not always taken into account in a correct way. Therefore a new approach to the interpretation of nuclear borehole logs is considered. It is based on the logs obtained with the natural gamma, the neutron porosity, the gamma density, and the pulsed neutron tools. For each of these tools a model, taking into account the important physical effects, is established. These models are incorporated into a computer programme which from the tool signals calculates, by use of iteration, a consistent set of the corresponding formation properties. In the paper the models developed for the four tools and the interpretation programme are briefly described. An example of the use of the interpretation programme is given and compared with a conventional interpretation. (author)

Preoperational baseline and site characterization report for the Environmental Restoration Disposal Facility

International Nuclear Information System (INIS)

Weekes, D.C.; Ford, B.H.; Jaeger, G.K.

1996-09-01

This document Volume 2 in a two-volume series that comprise the site characterization report for the Environmental Restoration Disposal Facility. Volume 1 contains data interpretation and information supporting the conclusions in the main text. This document presents original data in support of Volume 1 of the report. The following types of data are presented: well construction reports; borehole logs; borehole geophysical data; well development and pump installation; survey reports; and preoperational baseline chemical data and aquifer test data. This does not represent the entire body of data available. Other types of information are archived at BHI Document Control. Five ground water monitoring wells were drilled at the Environmental Restoration Disposal Facility site to directly investigate site- specific hydrogeologic conditions. Well and borehole activity summaries are presented in Volume 1. Field borehole logs and geophysical data from the drilling are presented in this document. Well development and pump installation sheets are presented for the groundwater monitoring wells. Other data presented in this document include borehole geophysical logs from existing wells; chemical data from the sampling of soil, vegetation, and mammals from the ERDF to support the preoperational baseline; ERDF surface radiation surveys;a nd aquifer testing data for well 699-32-72B

Determination of subsurface geological structure with borehole gravimetry

International Nuclear Information System (INIS)

Clark, S.R.; Hearst, J.R.

1983-07-01

Conventional gamma-gamma and gravimetric density measurements are routinely gathered for most holes used for underground nuclear tests. The logs serve to determine the subsurface structural geology near the borehole. The gamma-gamma density log measures density of the rock within about 15 cm of the borehole wall. The difference in gravity measured at two depths in a borehole can be interpreted in terms of the density of an infinite, homogeneous, horizontal bed between those depths. When the gravimetric density matches the gamma-gamma density over a given interval it is assumed that the bed actualy exists, and that rocks far from the hole must be the same as those encountered adjacent to the borehole. Conversely, when the gravimetric density differs from the gamma-gamma density it is apparent that the gravimeter is being influenced by a rock mass of different density than that at the hole wall. This mismatch can be a powerful tool to deduce the local structural geology. The geology deduced from gravity mesurements in emplacement hole, U4al, and the associated exploratory hole, UE4al, is an excellent example of the power of the method

Site investigation SFR. Boremap mapping of percussion drilled borehole HFR106

Energy Technology Data Exchange (ETDEWEB)

Winell, Sofia (Geosigma AB (Sweden))

2010-06-15

This report presents the result from the Boremap mapping of the percussion drilled borehole HFR106, which is drilled from an islet located ca 220 m southeast of the pier above SFR. The purpose of the location and orientation of the borehole is to investigate the possible occurrence of gently dipping, water-bearing structures in the area. HFR106 has a length of 190.4 m and oriented 269.4 deg/-60.9 deg. The mapping is based on the borehole image (BIPS), investigation of drill cuttings and generalized, as well as more detailed geophysical logs. The dominating rock type, which occupies 68% of HFR106, is fine- to medium-grained, pinkish grey metagranite-granodiorite (rock code 101057) mapped as foliated with a medium to strong intensity. Pegmatite to pegmatitic granite (rock code 101061) occupies 29% of the borehole. Subordinate rock types are felsic to intermediate meta volcanic rock (rock code 103076) and fine- to medium-grained granite (rock code 111058). Rock occurrences (rock types < 1 m in length) occupy about 16% of the mapped interval, of which half is veins, dykes and unspecified occurrences of pegmatite and pegmatitic granite. Only 5.5% of HFR106 is inferred to be altered, mainly oxidation in two intervals with an increased fracture frequency. A total number of 845 fractures are registered in HFR106. Of these are 64 interpreted as open with a certain aperture, 230 open with a possible aperture, and 551 sealed. This result in the following fracture frequencies: 1.6 open fractures/m and 3.0 sealed fractures/m. Three fracture sets of open and sealed fractures with the orientations 290 deg/70 deg, 150 deg/85 deg and 200 deg/85 deg can be distinguished in HFR106. The fracture frequency is generally higher in the second half of the borehole, and particularly in the interval 176-187.4 m.

Site investigation SFR. Boremap mapping of percussion drilled borehole HFR106

International Nuclear Information System (INIS)

Winell, Sofia

2010-06-01

This report presents the result from the Boremap mapping of the percussion drilled borehole HFR106, which is drilled from an islet located ca 220 m southeast of the pier above SFR. The purpose of the location and orientation of the borehole is to investigate the possible occurrence of gently dipping, water-bearing structures in the area. HFR106 has a length of 190.4 m and oriented 269.4 deg/-60.9 deg. The mapping is based on the borehole image (BIPS), investigation of drill cuttings and generalized, as well as more detailed geophysical logs. The dominating rock type, which occupies 68% of HFR106, is fine- to medium-grained, pinkish grey metagranite-granodiorite (rock code 101057) mapped as foliated with a medium to strong intensity. Pegmatite to pegmatitic granite (rock code 101061) occupies 29% of the borehole. Subordinate rock types are felsic to intermediate meta volcanic rock (rock code 103076) and fine- to medium-grained granite (rock code 111058). Rock occurrences (rock types < 1 m in length) occupy about 16% of the mapped interval, of which half is veins, dykes and unspecified occurrences of pegmatite and pegmatitic granite. Only 5.5% of HFR106 is inferred to be altered, mainly oxidation in two intervals with an increased fracture frequency. A total number of 845 fractures are registered in HFR106. Of these are 64 interpreted as open with a certain aperture, 230 open with a possible aperture, and 551 sealed. This result in the following fracture frequencies: 1.6 open fractures/m and 3.0 sealed fractures/m. Three fracture sets of open and sealed fractures with the orientations 290 deg/70 deg, 150 deg/85 deg and 200 deg/85 deg can be distinguished in HFR106. The fracture frequency is generally higher in the second half of the borehole, and particularly in the interval 176-187.4 m

Subsurface fracture surveys using a borehole television camera and an acoustic televiewer

International Nuclear Information System (INIS)

Lau, J.S.O.; Auger, L.F.

1987-01-01

Borehole television survey and acoustic televiewer logging provide rapid, cost-effective, and accurate methods of surveying fractures and their characteristics within boreholes varying in diameter from 7.6 to 15.3 cm. In the television survey, a camera probe is used to inspect the borehole walls. Measurements of location, orientation, infilling width, and aperture of fractures are made on the television screen and recorded on computer data record sheets. All observations are recorded on video cassette tapes. With the acoustic televiewer, oriented images of fractures in the borehole walls are recorded on a strip-chart log and also on video cassette tapes. The images are displayed as if the walls were split vertically along magnetic north and spread out horizontally. Measurements of fracture characteristics are made on the strip-chart log, using a digitizing table and a microcomputer, and the data recorded on floppy diskettes. In both surveys, an inclined fracture is displayed as a sinusoidal curve, from which the apparent orientation of the fracture can be measured. Once the borehole orientation is known, the true orientation of the fracture can be computed from its apparent orientation. Computer analysis of the fracture data, provides a rapid assessment of fracture occurrence, fracture aperture, and statisically significant concentrations of fracture orientations

Permeability Estimation Directly From Logging-While-Drilling Induced Polarization Data

DEFF Research Database (Denmark)

Fiandaca, G.; Maurya, P.K.; Balbarini, Nicola

2018-01-01

In this study we present the prediction of permeability from time‐domain spectral induced polarization (IP) data, measured in boreholes on undisturbed formations using the El‐log logging‐while‐drilling technique. We collected El‐log data and hydraulic properties on unconsolidated Quaternary...... and Miocene deposits in boreholes at three locations at a field site in Denmark, characterized by different electrical water conductivity and chemistry. The high vertical resolution of the El‐log technique matches the lithological variability at the site, minimizing ambiguity in the interpretation originating...

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

Energy Technology Data Exchange (ETDEWEB)

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

2006-04-15

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

Computer modeling and laboratory experiments of a specific borehole to surface electrical monitoring technique (BSEMT)

NARCIS (Netherlands)

Meekes, J.A.C.; Zhang, X.; Abdul Fattah, R.

2011-01-01

Geophysical monitoring of the dynamical behavior of subsurface reservoirs (oil, gas, CO2) remains an important issue in geophysical research. A new idea for reservoir monitoring based on electrical resistivity tomography was developed at TNO. The essential element of the so-called BSEMT (Borehole to

VTT test borehole for bedrock investigations

International Nuclear Information System (INIS)

Okko, O.; Hassinen, P.; Front, K.

1994-02-01

A borehole of depth 150 m and diameter 56 mm has been drilled in the area adjacent to the premises of the Technical Research Centre of Finland (VTT) at Otaniemi, Espoo, for the purposes of calibrating geophysical measurements devices. This report presents the test results obtained so far and illustrates the processing of these, in which the various measurements are plotted as curves and combinations of curves. The interpretations provided so far consists of analyses of lithological variations, bedrock fracturing, the nature and occurrence of fracture zones and groundwater flow patterns. Samples were taken from those parts of the core shown by the borehole measurements to be homogenous and thin sections made from these for mineralogical determinations. The rock mechanical and petrophysical properties of the same points were examined. The core is in the possession of VTT, and the hole itself is available to outsiders for the calibration and testing of borehole measurement equipment. (orig.). (21 refs., 13 figs., 5 tabs.)

NNWSI [Nevada Nuclear Waste Storage Investigations] hole histories

International Nuclear Information System (INIS)

1986-11-01

This report is a compilation of data from sixteen boreholes drilled under the guidance of the US Geological Survey to help identify the area's water table. The sixteen boreholes were drilled between April 1983 and November 1983 in Area 25, Nevada Test Site land and in Bureau of Land Management land adjacent to the Nevada Test Site. Data presented in the hole histories include all locations, daily activities, review of hole conditions, geophysical log lists, video tape lists, and microfiche copies of the geophysical logs run by the Fenix and Scisson, Inc. subcontractor

Preliminary hydrogeologic assessment of boreholes UE-25c No. 1, UE-25c No. 2, and UE-25c No. 3, Yucca Mountain, Nye County, Nevada; Water-resources investigations report 92-4016

Energy Technology Data Exchange (ETDEWEB)

Geldon, A.L.

1993-12-31

The purpose of this report is to characterize the hydrogeology of saturated tuffaceous rocks penetrated by boreholes UE-25c No. 1, UE-25c No.2, and UE-25c No. 3. These boreholes are referred to collectively in this report as the C-holes. The C-holes were drilled to perform multiwell aquifer tests and tracer tests; they comprise the only complex of closely spaced boreholes completed in the saturated zone at Yucca Mountain. Results of lithologic and geophysical logging, fracture analyses, water-level monitoring, temperature and tracejector surveys, aquifer tests, and hydrochemical sampling completed at the C-hole complex as of 1986 are assessed with respect to the regional geologic and hydrologic setting. A conceptual hydrogeological model of the Yucca Mountain area is presented to provide a context for quantitatively evaluating hydrologic tests performed at the C-hole complex as of 1985, for planning and interpreting additional hydrologic tests at the C-hole complex, and for possibly re-evaluating hydrologic tests in boreholes other than the C-holes.

Development of interpretation models for PFN uranium log analysis

International Nuclear Information System (INIS)

Barnard, R.W.

1980-11-01

This report presents the models for interpretation of borehole logs for the PFN (Prompt Fission Neutron) uranium logging system. Two models have been developed, the counts-ratio model and the counts/dieaway model. Both are empirically developed, but can be related to the theoretical bases for PFN analysis. The models try to correct for the effects of external factors (such as probe or formation parameters) in the calculation of uranium grade. The theoretical bases and calculational techniques for estimating uranium concentration from raw PFN data and other parameters are discussed. Examples and discussions of borehole logs are included

RCRA Facility investigation report for Waste Area Grouping 6 at Oak Ridge National Laboratory, Oak Ridge, Tennessee

International Nuclear Information System (INIS)

1991-09-01

This report describes the borehole geophysical logging performed at selected monitoring wells at waste area grouping (WAG) 6 of Oak Ridge National Laboratory in support of the WAG 6 Resource Conservation and Recovery Act Facility Investigation (RFI). It identifies the locations and describes the methods, equipment used in the effort, and the results of the activity. The actual logs for each well logged are presented in Attachment 1 through 4 of the TM. Attachment 5 provide logging contractor service literature and Attachment 6 is the Oak Ridge National Laboratory (ORNL) Procedure for Control of a Nuclear Source Utilized in Geophysical logging. The primary objectives of the borehole geophysical logging program were to (1) identify water-bearing fractured bedrock zones to determine the placement of the screen and sealed intervals for subsequent installation, and (2) further characterize local bedrock geology and hydrogeology and gain insight about the deeper component of the shallow bedrock aquifer flow system. A secondary objective was to provide stratigraphic and structural correlations with existing logs for Hydraulic Head Monitoring Station (HHMS) wells, which display evidence of faulting

Double-transmitting and Sextuple-receiving Borehole Transient Electromagnetic Method and Experimental Study

Directory of Open Access Journals (Sweden)

Bo Wang

2017-04-01

Full Text Available With the continuous improvement of precision requirements for borehole geophysical exploration, the application of transient electromagnetic method (from now on referred to as TEM in a borehole has become a hot spot. The conventional borehole TEM can only determine the longitudinal depth of the geological anomaly, the radial azimuth and depth cannot be resolved. A double-transmitting and sextuple-receiving borehole TEM is proposed, through which the radial anomaly is excited by the electromagnetic field generated by the double-emitting loops, and the azimuth and depth of the anomaly will be identified by the difference characteristics of the six receiving loops signals. In this paper, the response equations of the transmitting-receiving mode of double-transmitting and sextuple-receiving borehole TEM are deduced, and the response characteristics of the induction segment and the attenuation segment of the receiving loops are obtained based on the response equations under ramp function turn-off condition, providing the basis for theoretical analysis. Due to the negative value of the double-transmitting and sextuple-receiving transient electromagnetic response signals, a negative transformation algorithm under the double logarithmic coordinate system is proposed to provide the essential method for the analysis of two kinds of physical simulation experimental data of the radial azimuth and radial depth detection of the anomaly. The results show that the double-transmitting and sextuple-receiving borehole TEM has decent resolution ability in detecting the radial azimuth of the anomaly, and the effective resolution is 30°. The geometric difference among induced voltages of different measuring points can be used to evaluate the radial depth of the anomaly qualitatively. It is expected that the double-transmitting and sextuple-receiving borehole TEM can provide technical guidance for little borehole geophysical exploration in the fields of oil, natural

Geophysical survey for proposed borehole 199-K-107A, 100-K Area

International Nuclear Information System (INIS)

Mitchell, T.H.

1994-01-01

The objective of the survey was to locate subsurface obstructions that may affect the drilling of proposed borehole, 199-K-107A, located about 100 ft northwest of the 105 KW Building, 100-K Area. Based upon the results of the survey, possible drill sites within the zone, with the least likelihood of encountering identified obstructions, were identified. The ground-penetrating radar (GPR) system used for this work utilized a 300-megahertz antenna to transmit the electromagnetic (EM) energy into the ground. The transmitted energy is reflected back to a receiving antenna where variations in the return signal are recorded. Common reflectors include natural geologic conditions such as bedding, cementation, moisture, and clay, or man-made objects such as pipes, barrels, foundations, and buried wires. Several isolated anomalies, at various depths, are observed in the data. Additionally, two areas that appear disturbed, with perplexing character, are plotted. Because of the uncertain nature of these two areas, they were avoided when recommending a borehole location. Initially, the proposed borehole was staked at N130/E122. The new proposed borehole location is N139/E176. This location appears free of anomalies and is over 10 ft from interpreted linear anomalies/pipe-like features

Analysis of the magnetic susceptibility well log in drill hole UE25a-5, Yucca Mountain, Nevada Test Site

International Nuclear Information System (INIS)

Hagstrum, J.T.; Daniels, J.J.; Scott, J.H.

1980-01-01

Magnetic susceptibility measurements have been shown to be dependent upon the magnetite content of rocks with variations in rock susceptibility arising from changes in the shape, size, composition, and quantity of the contained magnetite grains. The present study was undertaken to determine the factor(s) responsible for the variation in magnetic susceptibility measurements from borehole UE25a-5 on the Nevada Test Site (NTS). The well logs and sample analyses presented in this paper form part of a larger geophysical well-logging project studying the physical properties of welded tuffs at NTS. The ash-flow sheets at NTS appear to be the products of single compositionally zoned magmas that tend, within a cooling unit, to erupt hotter, more mafic, and more crystal-rich with time. These factors, however, have little effect on the degree to which the tuffs become welded. Furthermore, zones of crystallization and alteration are superimposed upon the welded units. X-ray data show poor correspondence between the relative abundance of magnetite in a sample and the borehole magnetic susceptibility measurement associated with it. Curie balance experiments demonstrate no change in the magnetic mineralogy that could account for the susceptibility variation. Thin-section observations corroborate the x-ray data, but indicate a proportional relationship between the borehole susceptibility measurements and the grain-size distribution of magnetite. The association of magnetic susceptibility anomalies with the crystal-rich zones of the welded tuffs will aid in the identification and correlation of the eruptive sequences at NTS

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

Science.gov (United States)

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

2014-01-01

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

Site characterization and validation - drift and borehole fracture data. Stage 1

International Nuclear Information System (INIS)

Gale, J.; Straahle, A.

1988-09-01

This report describes the procedures used in mapping fractures intersecting seven scanlines along the southern and eastern boundaries of the Site Characterization and Validation (SCV) site and the procedures used in logging and orienting the fractures intersecting the core from six 'boundary boreholes' that were drilled as part of the site characterization program for the SCV site at the 360 m level in the Stripa mine. Scanline mapping along the mine drifts provided a detailed description of the fracture geomentry on the boundaries of the SCV site. The cores from the boundary boreholes have been logged, reconstructed and oriented using a borehole Televiewer and a borehole TV camera and the true fracture orientations calcilated. This has provide additional data on the fracture geometry within the SCV site. The fractire data from both the scanlines and the core logging are presented in the appendices. In addition, an initial analysis has been completed of the fracture orientations, trace lengths and spacings. Based on the variation in fracture orientations over the SCV site, there are two strong subvertical fracture sets or or clusters and a poorly represented sub-horizontal fracture set. An empirical approach, based on the 'blind zone' concept has been used to correct for orientation bias and to predict the orientations of the fracture system that will be intersected by the C and D boreholes in stage III. (33 figs., 6 tabl., 19 refs.)

Review of geophysical characterization methods used at the Hanford Site

International Nuclear Information System (INIS)

GV Last; DG Horton

2000-01-01

This paper presents a review of geophysical methods used at Hanford in two parts: (1) shallow surface-based geophysical methods and (2) borehole geophysical methods. This review was not intended to be ''all encompassing'' but should represent the vast majority (>90% complete) of geophysical work conducted onsite and aimed at hazardous waste investigations in the vadose zone and/or uppermost groundwater aquifers. This review did not cover geophysical methods aimed at large-scale geologic structures or seismicity and, in particular, did not include those efforts conducted in support of the Basalt Waste Isolation Program. This review focused primarily on the more recent efforts

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

Indian Academy of Sciences (India)

In the oil industry, acoustic borehole logging is commonly practiced. A borehole is drilled in a potential hydro-carbon reservoir and then probed with an acoustic ...... The non-dimensional phase velocity c/Vmin, Vmin = min(V1,V2,V3,V4) is computed at different values of non-dimensional wavenumber ka varying from 0 to 85.

Observations of joint persistence and connectivity across boreholes

Energy Technology Data Exchange (ETDEWEB)

Thapa, B.B.; Karasaki, K.

1996-01-01

Observations of joint persistence and connectivity are made by comparison of digital borehole wall images of fractures, fluid conductivity logs and hydraulic injections test results. The fractures were found to be generally impersistent across vertical boreholes about 8 m apart. Many hydraulic connections were found in the same volume of rock. Direct connections through single fractures seem to be rare and connectivity appears to be controlled by fracture networks, even over small volumes.

Utilization of test boreholes in prospecting and mining operations

International Nuclear Information System (INIS)

Sierak, J.P.

1987-01-01

Test boreholes are of fundamental importance for mining and prospecting operations. The drilling techniques are suited to the geological conditions and to the nature of the information desired. At Cogema, non-coring test boreholes, mainly drilled by a rotary percussive method, represent over 90% of the footage drilled; they achieve impressive performances at a cost which is by far less than that of coring test boreholes. The geological exploitation of these test boreholes is effected by a combined investigation of well logging and of cuttings. These investigations lead to an assessment for certain substances like uranium or coal or they mark the limits for favourable zones which alone will form the object of coring boreholes. In mining operations, boreholes indicate the definition for workable panels; they ensure at less cost the distribution of fluids, the forwarding of stowing material and the mine ventilation [fr

Simultaneous thermal neutron decay time and porosity logging system

International Nuclear Information System (INIS)

Schultz, W.E.; Smith, H.D.; Smith, M.P.

1980-01-01

An improved method and apparatus are described for simultaneously measuring the porosity and thermal neutron capture cross section of earth formations in situ in the vicinity of a well borehole using pulsed neutron well logging techniques. The logging tool which is moved through the borehole consists of a 14 MeV pulsed neutron source, an epithermal neutron detector and a combination gamma ray and fast neutron detector. The associated gating systems, counters and combined digital computer are sited above ground. (U.K.)

The potentialities of nuclear geophysical methods in ore testing of ferrous metals

International Nuclear Information System (INIS)

Ochkur, A.P.; Voznesenskij, L.I.; Fedorov, S.V.

1976-01-01

To study iron ores of simple composition, the gamma-gamma method is used successfully, determining iron contents in boreholes, in the walls of mine workings and in sampling hacked off rocks. The X-ray diffraction method is used effectively in analysing iron ores of complex composition ensuring that the contents of Fe, Mn and Ca are determined in them. Neutron-capture spectrometric gamma-logging is a promising method for determining the total iron content in the mined ore. Manganese ores are singled out in the boreholes by data from thermal neutron and neutron-activation logging. The X-ray diffraction method is used to analyse powder samples in mine workings. To single out and estimate chromites in boreholes, a combination of neutron-capture spectrometric gamma-logging, gamma-gamma logging and epithermal neutron-neutron logging is used. The X-ray diffraction method determines the contents of Cr, Ca and Fe in powder and coarse-ground samples of chromites

Joint inversion of geophysical data for site characterization and restoration monitoring. FY97 annual progress report for EMSP

International Nuclear Information System (INIS)

Berge, P.A.; Berryman, J.G.; Bonner, B.P.; Roberts, J.J.; Wildenschild

1997-01-01

'The purpose of this project is to develop a computer code for joint in-version of seismic and electrical data, to improve underground imaging for site characterization and remediation monitoring. The computer code developed in this project will invert geophysical data to obtain direct estimates of porosity and saturation underground, rather than inverting for seismic velocity and electrical resistivity or other geophysical properties. This is intended to be a significant improvement in the state-of-the-art of under-ground imaging, since interpretation of data collected at a contaminated site would become much less subjective. The schedule of this project is as follows: In the first year, investigators perform laboratory measurements of elastic and electrical properties of sand-clay mixtures containing various fluids. Investigators also develop methods of relating measurable geophysical properties to porosity and saturation by using rock physics theories, geostatistical, and empirical techniques together with available laboratory measurements. In the second year, investigators finish any necessary laboratory measurements and apply the methods developed in the first year to invert available borehole log data to predict measured properties of cores and sediments from a borehole. Investigators refine the inversion code in the third year and carry out a field experiment to collect seismic and electrical data. Investigators then use the inversion code to invert the field data to produce estimates of porosity and saturation in the field area where the data were collected. This report describes progress made in the first year of this three-year project.'

Hydrogeological characterisation using cross-borehole ground penetration radar and electrical resistivity tomography

DEFF Research Database (Denmark)

Zibar, Majken Caroline Looms

2007-01-01

was characterized by ~30 m thick unsaturated zone consisting mainly of sands of varying coarseness. Following an instrumentation of 16 boreholes two geophysical methods (cross-borehole ground penetrating radar and electrical resistivity tomography) were applied during natural precipitation and forced infiltration...... properties of the subsurface. On the other hand, volumetric moisture content variations of up to 5% were observed during a 20-day long forced infiltration experiment. The cross-borehole electrical resistance tomography and ground penetrating radar data collected during this experiment were subsequently....... The methods provided estimates of soil moisture content and electrical resistivity variations among 12 m deep boreholes located 5 – 7 m apart. The moisture content change following natural precipitation was observed to be practically negligible, providing minimal information to constrain the dynamic...

Critical Zone structure inferred from multiscale near surface geophysical and hydrological data across hillslopes at the Eel River CZO

Science.gov (United States)

Lee, S. S.; Rempe, D. M.; Holbrook, W. S.; Schmidt, L.; Hahm, W. J.; Dietrich, W. E.

2017-12-01

Except for boreholes and road cut, landslide, and quarry exposures, the subsurface structure of the critical zone (CZ) of weathered bedrock is relatively invisible and unmapped, yet this structure controls the short and long term fluxes of water and solutes. Non-invasive geophysical methods such as seismic refraction are widely applied to image the structure of the CZ at the hillslope scale. However, interpretations of such data are often limited due to heterogeneity and anisotropy contributed from fracturing, moisture content, and mineralogy on the seismic signal. We develop a quantitative framework for using seismic refraction tomography from intersecting geophysical surveys and hydrologic data obtained at the Eel River Critical Zone Observatory (ERCZO) in Northern California to help quantify the nature of subsurface structure across multiple hillslopes of varying topography in the area. To enhance our understanding of modeled velocity gradients and boundaries in relation to lithological properties, we compare refraction tomography results with borehole logs of nuclear magnetic resonance (NMR), gamma and neutron density, standard penetration testing, and observation drilling logs. We also incorporate laboratory scale rock characterization including mineralogical and elemental analyses as well as porosity and density measurements made via pycnometry, helium and mercury porosimetry, and laboratory scale NMR. We evaluate the sensitivity of seismically inferred saprolite-weathered bedrock and weathered-unweathered bedrock boundaries to various velocity and inversion parameters in relation with other macro scale processes such as gravitational and tectonic forces in influencing weathered bedrock velocities. Together, our sensitivity analyses and multi-method data comparison provide insight into the interpretation of seismic refraction tomography for the quantification of CZ structure and hydrologic dynamics.

Computer model for calculating gamma-ray pulse-height spectra for logging applications

International Nuclear Information System (INIS)

Evans, M.L.

1981-01-01

A generalized computer model has been devised to simulate the emission, transport, and detection of natural gamma radiation from various logging environments. The model yields high-resolution gamma-ray pulse-height spectra that can be used to correct both gross gamma and spectral gamma-ray logs. The technique can help provide corrections to airborne and surface radiometric survey logs for the effects of varying altitude, formation composition, and overburden. Applied to borehole logging, the model can yield estimates of the effects of varying borehole fluid and casing attenuations, as well as varying formation porosity and saturation

Influence of borehole-eccentred tools on wireline and logging-while-drilling sonic logging measurements

KAUST Repository

Pardo, David; Matuszyk, Paweł Jerzy; Torres-Verdí n, Carlos; Mora Cordova, Angel; Muga, Ignacio; Calo, Victor M.

2013-01-01

We describe a numerical study to quantify the influence of tool-eccentricity on wireline (WL) and logging-while-drilling (LWD) sonic logging measurements. Simulations are performed with a height-polynomial-adaptive (hp) Fourier finite-element method

Review of geophysical characterization methods used at the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

GV Last; DG Horton

2000-03-23

This paper presents a review of geophysical methods used at Hanford in two parts: (1) shallow surface-based geophysical methods and (2) borehole geophysical methods. This review was not intended to be ``all encompassing'' but should represent the vast majority (>90% complete) of geophysical work conducted onsite and aimed at hazardous waste investigations in the vadose zone and/or uppermost groundwater aquifers. This review did not cover geophysical methods aimed at large-scale geologic structures or seismicity and, in particular, did not include those efforts conducted in support of the Basalt Waste Isolation Program. This review focused primarily on the more recent efforts.

Results of 1999 Spectral Gamma-Ray and Neutron Moisture Monitoring of Boreholes at Specific Retention Facilities in the 200 East Area, Hanford Site

Energy Technology Data Exchange (ETDEWEB)

DG Horton; RR Randall

2000-01-18

Twenty-eight wells and boreholes in the 200 East Are% Hanford Site, Washington were monitored in 1999. The monitored facilities were past-practice liquid waste disposal facilities and consisted of six cribs and nineteen ''specific retention'' cribs and trenches. Monitoring consisted of spectral gamma-ray and neutron moisture logging. All data are included in Appendix B. The isotopes {sup 137}Cs, {sup 60}Co, {sup 235}U, {sup 238}U, and {sup 154}Eu were identified on spectral gamma logs from boreholes monitoring the PUREX specific retention facilities; the isotopes {sup 137}Cs, {sup 60}Co, {sup 125}Sb, and {sup 154}Eu were identified on the logs from boreholes at the BC Controlled Area cribs and trenches; and {sup 137}Cs, {sup 60}Co, and {sup 125}Sb were, identified on the logs from boreholes at the BX specific retention trenches. Three boreholes in the BC Controlled Area and one at the BX trenches had previous spectral gamma logs available for comparison with 1999 logs. Two of those logs showed that changes in the subsurface distribution of {sup 137}CS and/or {sup 60}Co had occurred since 1992. Although the changes are not great, they do point to continued movement of contaminants in the vadose zone. The logs obtained in 1999 create a larger baseline for comparison with future logs. Numerous historical gross gamma logs exist from most of the boreholes logged. Qualitative comparison of those logs with the 1999 logs show many substantial changes, most of which reflect the decay of deeper short-lived isotopes, such as {sup 106}Ru and {sup 125}Sb, and the much slower decay of shallower and longer-lived isotopes such as {sup 137}Cs. The radionuclides {sup 137}Cs and {sup 60}Co have moved in two boreholes since 1992. Given the amount of movement and the half-lives of the isotopes, it is expected that they will decay to insignificant amounts before reaching groundwater. However, gamma ray logging cannot detect many of the contaminants of interest such

Compiling geophysical and geological information into a 3-D model of the glacially-affected island of Föhr

Directory of Open Access Journals (Sweden)

T. Burschil

2012-10-01

Full Text Available Within the scope of climatic change and associated sea level rise, coastal aquifers are endangered and are becoming more a focus of research to ensure the future water supply in coastal areas. For groundwater modelling a good understanding of the geological/hydrogeological situation and the aquifer behavior is necessary. In preparation of groundwater modelling and assessment of climate change impacts on coastal water resources, we setup a geological/hydrogeological model for the North Sea Island of Föhr.

Data from different geophysical methods applied from the air, the surface and in boreholes contribute to the 3-D model, e.g. airborne electromagnetics (SkyTEM for spatial mapping the resistivity of the entire island, seismic reflections for detailed cross-sections in the groundwater catchment area, and geophysical borehole logging for calibration of these measurements. An iterative and integrated evaluation of the results from the different geophysical methods contributes to reliable data as input for the 3-D model covering the whole island and not just the well fields.

The complex subsurface structure of the island is revealed. The local waterworks use a freshwater body embedded in saline groundwater. Several glaciations reordered the youngest Tertiary and Quaternary sediments by glaciotectonic thrust faulting, as well as incision and refill of glacial valleys. Both subsurface structures have a strong impact on the distribution of freshwater-bearing aquifers. A digital geological 3-D model reproduces the hydrogeological structure of the island as a base for a groundwater model. In the course of the data interpretation, we deliver a basis for rock identification.

We demonstrate that geophysical investigation provide petrophysical parameters and improve the understanding of the subsurface and the groundwater system. The main benefit of our work is that the successful combination of electromagnetic, seismic and borehole

Characterization of fractures and flow zones in a contaminated crystalline-rock aquifer in the Tylerville section of Haddam, Connecticut

Science.gov (United States)

Johnson, Carole D.; Kiel, Kristal F.; Joesten, Peter K.; Pappas, Katherine L.

2016-10-04

The U.S. Geological Survey, in cooperation with the Connecticut Department of Energy and Environmental Protection, investigated the characteristics of the bedrock aquifer in the Tylerville section of Haddam, Connecticut, from June to August 2014. As part of this investigation, geophysical logs were collected from six water-supply wells and were analyzed to (1) identify well construction, (2) determine the rock type and orientation of the foliation and layering of the rock, (3) characterize the depth and orientation of fractures, (4) evaluate fluid properties of the water in the well, and (5) determine the relative transmissivity and head of discrete fractures or fracture zones. The logs included the following: caliper, electromagnetic induction, gamma, acoustic and (or) optical televiewer, heat-pulse flowmeter under ambient and pumped conditions, hydraulic head data, fluid electrical conductivity and temperature under postpumping conditions, and borehole-radar reflection collected in single-hole mode. In a seventh borehole, a former water-supply well, only caliper, fluid electrical conductivty, and temperature logs were collected, because of a constriction in the borehole.This report includes a description of the methods used to collect and process the borehole geophysical data, the description of the data collected in each of the wells, and a comparison of the results collected in all of the wells. The data are presented in plots of the borehole geophysical logs, tables, and figures. Collectively these data provide valuable characterizations that can be used to improve or inform site conceptual models of groundwater flow in the study area.

Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods

Energy Technology Data Exchange (ETDEWEB)

Keating, Kristina [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Slater, Lee [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Ntarlagiannis, Dimitris [Rutgers Univ., Newark, NJ (United States). Dept. of Earth and Environmental Sciences; Williams, Kenneth H. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Earth Sciences Division

2015-02-24

This documents contains the final report for the project "Integrated Geophysical Measurements for Bioremediation Monitoring: Combining Spectral Induced Polarization, Nuclear Magnetic Resonance and Magnetic Methods" (DE-SC0007049) Executive Summary: Our research aimed to develop borehole measurement techniques capable of monitoring subsurface processes, such as changes in pore geometry and iron/sulfur geochemistry, associated with remediation of heavy metals and radionuclides. Previous work has demonstrated that geophysical method spectral induced polarization (SIP) can be used to assess subsurface contaminant remediation; however, SIP signals can be generated from multiple sources limiting their interpretation value. Integrating multiple geophysical methods, such as nuclear magnetic resonance (NMR) and magnetic susceptibility (MS), with SIP, could reduce the ambiguity of interpretation that might result from a single method. Our research efforts entails combining measurements from these methods, each sensitive to different mineral forms and/or mineral-fluid interfaces, providing better constraints on changes in subsurface biogeochemical processes and pore geometries significantly improving our understanding of processes impacting contaminant remediation. The Rifle Integrated Field Research Challenge (IFRC) site was used as a test location for our measurements. The Rifle IFRC site is located at a former uranium ore-processing facility in Rifle, Colorado. Leachate from spent mill tailings has resulted in residual uranium contamination of both groundwater and sediments within the local aquifer. Studies at the site include an ongoing acetate amendment strategy, native microbial populations are stimulated by introduction of carbon intended to alter redox conditions and immobilize uranium. To test the geophysical methods in the field, NMR and MS logging measurements were collected before, during, and after acetate amendment. Next, laboratory NMR, MS, and SIP measurements

Aim and points of this workshop: The 2. Workshop on Seismic Observation in Deep Borehole (SODB) and its Applications

International Nuclear Information System (INIS)

Sugiyama, Yuichi

2014-01-01

The achievements of the first WS and the aim of the Second WS were explained. The purposes of this Second WS were: to re-recognize the significance of seismic ground motion evaluation based on newly added deep borehole seismic observation in addition to existing borehole investigation, geological surveys, and geophysical exploration; to acknowledge deep borehole seismic observation and geophysical exploration (hardware) as well as the site characteristic evaluation method (software) required for seismic ground motion evaluation; and to consolidate opinions on multi-purpose application of observation technology and data as well as acknowledge issues to be addressed and technological problems. The final goals of this WS were to clarify items and issues that present challenges for the future based on the discussions in this WS. (author)

System for gamma-gamma formation density logging while drilling

International Nuclear Information System (INIS)

Paske, W.C.

1991-01-01

The patent relates to a system for logging subterranean formations for the determination of formation density by using gamma radiation. Gamma ray source and detection means are disposed within a housing adapted for positioning within a borehole for the emission and detection of gamma rays propagating through earth formations and borehole drilling fluid. The gamma ray detection means comprises first and second gamma radiation sensors geometrically disposed within the housing, the same longitudinal distance from the gamma ray source and diametrically opposed in a common plane. A formation matrix density output signal is produced in proportion to the output signal from each of the gamma ray sensors and in conjunction with certain constants established by the geometrical configuration of the sensors relative to the gamma ray source and the borehole diameter. Formation density is determined without regard to the radial position of the logging probe within the borehole in a measuring while drilling mode. 6 figs

Characterization of earthquake fault by borehole experiments; Koseinai sokutei ni yoru jishin danso no kenshutsu

Energy Technology Data Exchange (ETDEWEB)

Ito, H; Miyazaki, T; Nishizawa, O; Kuwahara, Y; Kiguchi, T [Geological Survey of Japan, Tsukuba (Japan)

1996-05-01

A borehole was excavated to penetrate the Nojima fault at the Hirabayashi area, to investigate the underground structures of the fault by observation of the cores and well logging. The borehole was excavated from 74.6m east of the fault surface. Soil is of granodiorite from the surface, and fault clay at a depth in a range from 624.1 to 625.1m. Observation of the cores, collected almost continuously, indicates that the fault fracture zone expands in a depth range from 557 to 713.05m. The well logging experiments are natural potential, resistivity, density, gamma ray, neutron, borehole diameter, microresistivity and temperature. They are also for DSI- and FMI-observation, after expansion of the borehole. The well logging results indicate that resistivity, density and elastic wave velocity decrease as distance from fault clay increases, which well corresponds to the soil conditions. The BHTV and FMI analyses clearly detect the fault clay demarcations, and show that elastic wave velocity and BHTV results differ at above and below the fault. 3 refs., 3 figs.

The value of DCIP geophysical surveys for contaminated site investigations

DEFF Research Database (Denmark)

Balbarini, Nicola; Rønde, Vinni Kampman; Maurya, Pradip Kumar

an old factory site by combining traditional geological, hydrological, and contaminant concentration data with DCIP surveys. The plume consisted of xenobiotic organic compounds and inorganics. The study assesses benefits and limitations of DCIP geophysics for contaminated site investigations. A 3D......Geophysical methods are increasingly being used in contaminant hydrogeology to map lithology, hydraulic properties, and contaminant plumes with a high ionic strength. Advances in the Direct Current resistivity and Induced Polarization (DCIP) method allow the collection of high resolution three...... water and below the streambed. Surface DCIP surveys supported the characterization of the spatial variability in geology, hydraulic conductivity and contaminant concentration. Though DCIP data interpretation required additional borehole data, the DCIP survey reduced the number of boreholes required...

A compendium of P- and S-wave velocities from surface-to-borehole logging; summary and reanalysis of previously published data and analysis of unpublished data

Science.gov (United States)

Boore, David M.

2003-01-01

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

Empirical Mode Decomposition of Geophysical Well-log Data of Bombay Offshore Basin, Mumbai, India

Science.gov (United States)

Siddharth Gairola, Gaurav; Chandrasekhar, Enamundram

2016-04-01

Geophysical well-log data manifest the nonlinear behaviour of their respective physical properties of the heterogeneous subsurface layers as a function of depth. Therefore, nonlinear data analysis techniques must be implemented, to quantify the degree of heterogeneity in the subsurface lithologies. One such nonlinear data adaptive technique is empirical mode decomposition (EMD) technique, which facilitates to decompose the data into oscillatory signals of different wavelengths called intrinsic mode functions (IMF). In the present study EMD has been applied to gamma-ray log and neutron porosity log of two different wells: Well B and Well C located in the western offshore basin of India to perform heterogeneity analysis and compare the results with those obtained by multifractal studies of the same data sets. By establishing a relationship between the IMF number (m) and the mean wavelength associated with each IMF (Im), a heterogeneity index (ρ) associated with subsurface layers can be determined using the relation, Im=kρm, where 'k' is a constant. The ρ values bear an inverse relation with the heterogeneity of the subsurface: smaller ρ values designate higher heterogeneity and vice-versa. The ρ values estimated for different limestone payzones identified in the wells clearly show that Well C has higher degree of heterogeneity than Well B. This correlates well with the estimated Vshale values for the limestone reservoir zone showing higher shale content in Well C than Well B. The ρ values determined for different payzones of both wells will be used to quantify the degree of heterogeneity in different wells. The multifractal behaviour of each IMF of both the logs of both the wells will be compared with one another and discussed on the lines of their heterogeneity indices.

Design of a borehole data-acquisition/transmission system. Final report, Volume I

International Nuclear Information System (INIS)

Hancock, R.L.; Bowden, J.C.

1981-06-01

Objective of the BDATS program was to design, construct, and demonstrate a borehole probe and associated uphole modules that would allow downhole collection of data from any of several borehole probes and would allow digital transmission of that data uphole to a computer. Specifically, the system was electrically and mechanically configured to interface to six separate borehole probes and a computer in a R and D logging vehicle. However, the system can be used with other types of probes

Soil and groundwater VOCs contamination: How can electrical geophysical measurements help assess post-bioremediation state?

Science.gov (United States)

Kessouri, P.; Johnson, T. C.; Day-Lewis, F. D.; Slater, L. D.; Ntarlagiannis, D.; Johnson, C. D.

2016-12-01

The former Brandywine MD (Maryland, USA) Defense Reutilization and Marketing Office (DRMO) was designated a hazardous waste Superfund site in 1999. The site was used as a storage area for waste and excess government equipment generated by several U.S. Navy and U.S. Air Force installations, leading to soil and groundwater contamination by volatile organic compounds (VOCs). Active bioremediation through anaerobic reductive dehalogenation was used to treat the groundwater and the aquifer unconsolidated materials in 2008, with electrical geophysical measurements employed to track amendment injections. Eight years later, we used spectral induced polarization (SIP) and time domain induced polarization (TDIP) on 2D surface lines and borehole electrical arrays to assess the long term impact of active remediation on physicochemical properties of the subsurface. Within the aquifer, the treated zone is more electrically conductive, and the phase shift describing the polarization effects is higher than in the untreated zone. Bulk conductivity and phase shift are also locally elevated close to the treatment injection well, possibly due to biogeochemical transformations associated with prolonged bacterial activity. Observed SIP variations could be explained by the presence of biofilms coating the pore space and/or by-products of the chemical reactions catalyzed by the bacterial activity (e.g. iron sulfide precipitation). To investigate these possibilities, we conducted complementary well logging measurements (magnetic susceptibility [MS], nuclear magnetic resonance [NMR], gamma-ray) using 5 boreholes installed at both treated and untreated locations of the site. We also collected water and soil samples on which we conducted microbiological and chemical analyses, along with geophysical observations (SIP, MS and NMR), in the laboratory. These measurements provide further insights into the physicochemical transformations in the subsurface resulting from the treatment and highlight

Engineering aspects of radiometric logging

International Nuclear Information System (INIS)

Huppert, P.

1982-01-01

Engineering problems encountered in the development of nuclear borehole logging techniques are discussed. Spectrometric techniques require electronic stability of the equipment. In addition the electronics must be capable of handling high count rates of randomly distributed pulses of fast rise time from the detector and the systems must be designed so that precise calibration is possible under field operating conditions. Components of a logging system are discussed in detail. They include the logging probe (electronics, detector, high voltage supply, preamplifier), electronic instrumentation for data collection and processing and auxiliary equipment

Borehole instrument for scintillation gamma spectrometer

International Nuclear Information System (INIS)

Sinitsyn, A.Ya.; Gabitov, R.M.

1979-01-01

Described are a schematic diagram and main specifications of a borehole instrument with autostabilization of energy scale measure by gamma bench-mark of 137 Cs, intended for the application in a logging gamma spectrometer to determine separately the concentrations of nature radioactive elements. The instrument may be connected to the KOBDFM-2 cable of 600 m length. It contains a scintillation counter for gamma quanta consisting of 30x70 mm NaI(Tl) crystal and a FEU-85 photoamplifier, an input conforming stage, a diagram of threshold pulse formation and regulating high-voltage generator. The borehole instrument has been proved under laboratory and field conditions at 10-40 deg C

Using geophysical techniques to control in situ thermal remediation

International Nuclear Information System (INIS)

Boyd, S.; Daily, W.; Ramirez, A.; Wilt, M.; Goldman, R.; Kayes, D.; Kenneally, K.; Udell, K.; Hunter, R.

1994-01-01

Monitoring the thermal and hydrologic processes that occur during thermal environmental remediation programs in near real-time provides essential information for controlling the process. Geophysical techniques played a crucial role in process control as well as for characterization during the recent Dynamic Underground Stripping Project demonstration in which several thousand gallons of gasoline were removed from heterogeneous soils both above and below the water table. Dynamic Underground Stripping combines steam injection and electrical heating for thermal enhancement with ground water pumping and vacuum extraction for contaminant removal. These processes produce rapid changes in the subsurface properties including changes in temperature fluid saturation, pressure and chemistry. Subsurface imaging methods are used to map the heated zones and control the thermal process. Temperature measurements made in wells throughout the field reveal details of the complex heating phenomena. Electrical resistance tomography (ERT) provides near real-time detailed images of the heated zones between boreholes both during electrical heating and steam injection. Borehole induction logs show close correlation with lithostratigraphy and, by identifying the more permeable gravel zones, can be used to predict steam movement. They are also useful in understanding the physical changes in the field and in interpreting the ERT images. Tiltmeters provide additional information regarding the shape of the steamed zones in plan view. They were used to track the growth of the steam front from individual injectors

Definition of a critical confining zone using surface geophysical methods

International Nuclear Information System (INIS)

Eddy-Dilek, C.A.; Looney, B.B.; Hoekstra, P.; Harthill, N.; Blohm, M.; Phillips, D.R.

1997-01-01

Definition of the hydrologic framework in layered sediments of fluvial and deltaic origin is a difficult challenge for environmental characterization and remediation programs due to the lithologic and stratigraphic heterogeneities inherent in these settings. The authors set out to use complementary geophysical surveys to determine the nature and extent of a deep confining unit at the Savannah River Site, South Carolina. Time Domain Electromagnetic (TDEM) soundings were used to define the electrical conductance of the clayey confining unit (aquitard), and shear-wave reflection seismic was used to define the stratigraphic framework. Based on correlations with borehole geophysical logs and sieve data, the shear-wave seismic proved capable of defining relatively fine layering in the coastal plain sediments, the upper and lower surfaces of a critical confining unit, and erosional features on the surface of the confining unit. The TDEM surveys defined the presence or absence of the clay facies of the confining unit. Moreover, by constraining the interpretation of the TDEM data with the thickness of the confining unit derived from the seismic data, the authors mapped the extent of the unit, showing where the clay is thicker, where it probably was never deposited, and where it was eroded by downcutting channels. These results have significant implications on the design and optimization of remedial systems

Application of log interpretation methods to evaluate heterogeneity in diatomaceous mudstone at Horonobe area

International Nuclear Information System (INIS)

Hara, Akio; Tsuji, Takashi; Nishimura, Mizue

2005-01-01

Borehole log interpretation methods, which are usually used by petroleum exploration companies, are applied for evaluating heterogeneity of deep underground diatomaceous mudstones in the Horonobe area. Natural gamma ray log and electrical micro image (EMI) log data were used for the log interpretation. Five sedimentary facies, A to E, were established from the EMI log interpretation. Significant correlations between the sedimentary facies, the chemical contents, the natural gamma ray level, and the electric conductivity in the diatomaceous mudstone were seen. Spatial distribution of the diatomaceous mudstone, in lithology and thickness, was recognized through borehole correlation, which seems to reflect the sedimentary environment change. (author)

Borehole geophysics for delineating the geological structure in the Sakonishi prospect, the Hida area, Japan; Hida chiiki Sako nishi chiku ni okeru boring ko riyo butsuri tansa ni yoru chishitsu kozo kaiseki

Energy Technology Data Exchange (ETDEWEB)

Katayama, H.; Hishida, H.; Yoshioka, K. [Metal Mining Agency of Japan, Tokyo (Japan)

1997-05-27

In order to discuss effectiveness of physical exploration in the Sakonishi prospect in the Hida area, physical exploration was carried out by utilizing bored wells. This area contains the Kamioka mine, one of the major base metal mines in Japan, where electrical exploration has been attempted several times in the past. No effective results have been obtained, however, because specific resistance contrast between mine beds and base rocks is too small, and the topography is too steep making site workability inferior. As part of the investigations on geological structures over wide areas, electrical logging (specific resistance and natural potential) was performed in fiscal 1995 and 1996 by utilizing the boreholes. Induced polarization logging was also conducted on the same boreholes. A traverse line on the ground with a length of 600 m and boreholes were used to execute specific resistance tomography. Clear extraction was possible on a fault structure which is thought related with limestone distribution and mine bed creation. However, it was not possible to identify upward continuity of zinc ores expected in the exploration. Because of not large a specific resistance contrast between zinc ores and base rocks, it is difficult to find mine bed locations only from the information on the specific resistance. 5 refs., 5 figs., 1 tab.

Time-lapse electrical geophysical monitoring of amendment-based biostimulation

Science.gov (United States)

Johnson, Timothy C.; Versteeg, Roelof J.; Day-Lewis, Frederick D.; Major, William; Lane, John W.

2015-01-01

Biostimulation is increasingly used to accelerate microbial remediation of recalcitrant groundwater contaminants. Effective application of biostimulation requires successful emplacement of amendment in the contaminant target zone. Verification of remediation performance requires postemplacement assessment and contaminant monitoring. Sampling-based approaches are expensive and provide low-density spatial and temporal information. Time-lapse electrical resistivity tomography (ERT) is an effective geophysical method for determining temporal changes in subsurface electrical conductivity. Because remedial amendments and biostimulation-related biogeochemical processes often change subsurface electrical conductivity, ERT can complement and enhance sampling-based approaches for assessing emplacement and monitoring biostimulation-based remediation.Field studies demonstrating the ability of time-lapse ERT to monitor amendment emplacement and behavior were performed during a biostimulation remediation effort conducted at the Department of Defense Reutilization and Marketing Office (DRMO) Yard, in Brandywine, Maryland, United States. Geochemical fluid sampling was used to calibrate a petrophysical relation in order to predict groundwater indicators of amendment distribution. The petrophysical relations were field validated by comparing predictions to sequestered fluid sample results, thus demonstrating the potential of electrical geophysics for quantitative assessment of amendment-related geochemical properties. Crosshole radar zero-offset profile and borehole geophysical logging were also performed to augment the data set and validate interpretation.In addition to delineating amendment transport in the first 10 months after emplacement, the time-lapse ERT results show later changes in bulk electrical properties interpreted as mineral precipitation. Results support the use of more cost-effective surface-based ERT in conjunction with limited field sampling to improve spatial

Geophysical Signitures From Hydrocarbon Contaminated Aquifers

Science.gov (United States)

Abbas, M.; Jardani, A.

2015-12-01

The task of delineating the contamination plumes as well as studying their impact on the soil and groundwater biogeochemical properties is needed to support the remediation efforts and plans. Geophysical methods including electrical resistivity tomography (ERT), induced polarization (IP), ground penetrating radar (GPR), and self-potential (SP) have been previously used to characterize contaminant plumes and investigate their impact on soil and groundwater properties (Atekwana et al., 2002, 2004; Benson et al., 1997; Campbell et al., 1996; Cassidy et al., 2001; Revil et al., 2003; Werkema et al., 2000). Our objective was to: estimate the hydrocarbon contamination extent in a contaminated site in northern France, and to adverse the effects of the oil spill on the groundwater properties. We aim to find a good combination of non-intrusive and low cost methods which we can use to follow the bio-remediation process, which is planned to proceed next year. We used four geophysical methods including electrical resistivity tomography, IP, GPR, and SP. The geophysical data was compared to geochemical ones obtained from 30 boreholes installed in the site during the geophysical surveys. Our results have shown: low electrical resistivity values; high chargeability values; negative SP anomalies; and attenuated GPR reflections coincident with groundwater contamination. Laboratory and field geochemical measurements have demonstrated increased groundwater electrical conductivity and increased microbial activity associated with hydrocarbon contamination of groundwater. Our study results support the conductive model suggested by studies such as Sauck (2000) and Atekwana et al., (2004), who suggest that biological alterations of hydrocarbon contamination can substantially modify the chemical and physical properties of the subsurface, producing a dramatic shift in the geo-electrical signature from resistive to conductive. The next stage of the research will include time lapse borehole

Borehole tool outrigger arm displacement control mechanism

International Nuclear Information System (INIS)

Lee, A.G.

1985-01-01

As the outrigger arms of a borehole logging tool are flexed inwardly and outwardly according to the diameter of the borehole opening through which they pass, the corresponding axial displacements of the ends of the arms are controlled to determine the axial positions of the arms relative to the tool. Specifically, as the arm ends move, they are caused to rotate by a cam mechanism. The stiffness of the arms causes the arm ends to rotate in unison, and the exact positions of the arms on the tool are then controlled by the differential movements of the arm ends in the cams

Geophysical methods for evaluation of plutonic rocks

International Nuclear Information System (INIS)

Gibb, R.A.; Scott, J.S.

1986-04-01

Geophysical methods are systematically described according to the physical principle and operational mode of each method, the type of information produced, limitations of a technical and/or economic nature, and the applicability of the method to rock-mass evaluation at Research Areas of the Nuclear Fuel Waste Management Program. The geophysical methods fall into three categories: (1) airborne and other reconnaissance surveys, (2) detailed or surface (ground) surveys, and (3) borehole or subsurface surveys. The possible roles of each method in the site-screening and site-evaluation processes of disposal vault site selection are summarized

Geophysical experiments at Mariano Lake uranium orebody

International Nuclear Information System (INIS)

Thompson, D.T.

1980-01-01

Several geophysical experiments were performed over the Mariano Lake orebody before mining. Surface self-potential methods, surface-to-hole induced-polarization methods, and reflection-seismic methods were used. These geophysical techniques provided data which relate to the conceptual model of this orebody. Currents generated in the productive formation by oxidation-reduction reactions do not generate measurable potential anomalies at the surface. Surface-to-hole induced-polarization measurements apparently can detect an oxidation-reduction front in the vicinity of an exploration borehole. Reflection-seismic techniques can provide information concening the paleostructure of the area

Hydrogeologic testing of the E.J. Kubat borehole, San Juan County, Utah: utilization of a high pressure instrumented flow control system

International Nuclear Information System (INIS)

Hoexter, D.F.

1982-01-01

The E.J. Kubat borehole, located in San Juan County, Utah, in the SW 1/4, Section 23, T37S, R19E, was drilled in 1958 as a petroleum exploration (wildcat) well. Drilling records and geophysical logs were examined as a part of the Paradox Basin Project, a feasibility and siting study for a high-level nuclear waste repository to be located in bedded salt deposits in the Utah portion of the Paradox Basin. This project is part of the Department of Energy National Waste Terminal Storage Program, and is being conducted by Woodward-Clyde Consultants under subcontract to Battelle Memorial Institute, Office of Nuclear Waste Isolation. The geophysical logs of the Kubat and nearby wells showed that salt cycles potentially suitable as a possible repository horizon existed within the Pennsylvanian-age Paradox Formation in the area. Thus, it was decided to re-enter the well and extend it deeper into the Mississippian Leadville Limestone, the major water-bearing formation underlying the repository horizon. A series of hydrogeologic tests was conducted to evaluate hydrogeologic properties of the Leadville Limestone. These tests provided data on potentiometric level, transmissivity and permeability of the test interval. Although testing of relatively highly permeable formations is common, obtaining reliable data from formations of low permeability is more difficult, and is a special aspect of the paradox Basin Project

Synchronization of Well Log Data and Geophysical Data with Remote Sensing Technique to Develop the Hydrocarbon System of Bengal Basin

Science.gov (United States)

Kesh, S.; Samadder, P. K.

2012-12-01

Remote sensing along with more conventional exploration techniques such as geophysics and reconnaissance field mapping can help to establish regional geologic relationships, to extract major structural features and to pinpoint anomalous patterns. Many well have been drilled in Bengal basin still no commercially viable reserves have been discovered. Geophysical well logging is used in virtually every oil well. It is the primary means by which we characterize the subsurface in search of hydrocarbons. Oil and gas exploration activities for large areas require ground gravity surveys to facilitate detailed geological interpretations for subsurface features integrating geological cross-sections with the sub-surface structural trends leads to the identification of prospect areas. Remote sensing, geological and geophysical data integration provide accurate geometric shapes of the basins. Bengal basin has a sedimentary fill of 10-15 km, is the northernmost of the east coast basins of India In the first phase Remote sensing satellite sensors help in identifying surface anomaly which indicates the presence of hydrocarbon reservoirs providing regional geological settings of petroleferous basins. It provides accurate and visual data for directly determining geometric shapes of basin. It assists in the selection of exploration regions by defining the existence of sedimentary basin. Remote sensing methods can generate a wealth of information useful in determining the value of exploratory prospecting. In the second phase Well Log data provide relative subsurface information for oil and gas exploration. Remote sensing data are merged with other available information such as Aeromagnetic, gravity, geochemical surveys and 2D seismic surveys. The result of this phase is to estimate the outcome of oil discovery probabilities for locating oil prospects

Improved estimation of hydraulic conductivity by combining stochastically simulated hydrofacies with geophysical data.

Science.gov (United States)

Zhu, Lin; Gong, Huili; Chen, Yun; Li, Xiaojuan; Chang, Xiang; Cui, Yijiao

2016-03-01

Hydraulic conductivity is a major parameter affecting the output accuracy of groundwater flow and transport models. The most commonly used semi-empirical formula for estimating conductivity is Kozeny-Carman equation. However, this method alone does not work well with heterogeneous strata. Two important parameters, grain size and porosity, often show spatial variations at different scales. This study proposes a method for estimating conductivity distributions by combining a stochastic hydrofacies model with geophysical methods. The Markov chain model with transition probability matrix was adopted to re-construct structures of hydrofacies for deriving spatial deposit information. The geophysical and hydro-chemical data were used to estimate the porosity distribution through the Archie's law. Results show that the stochastic simulated hydrofacies model reflects the sedimentary features with an average model accuracy of 78% in comparison with borehole log data in the Chaobai alluvial fan. The estimated conductivity is reasonable and of the same order of magnitude of the outcomes of the pumping tests. The conductivity distribution is consistent with the sedimentary distributions. This study provides more reliable spatial distributions of the hydraulic parameters for further numerical modeling.

New roles of LWD and wireline logging in scientific ocean drilling

Science.gov (United States)

Sanada, Y.; Kido, Y. N.; Moe, K.; Aoike, K.

2014-12-01

D/V Chikyu implemented by CDEX/JAMSTEC joined IODP from 2007. Various LWD (Logging While Drilling) and wireline logging have been carried out in many expeditions and for various purposes. Significant features of logging in Chikyu expeditions are many use of LWD than wireline logging, and riser dirlling. riser selected specific tools for each scientific target, and 3) carried out various borehole experiments. LWD has been more popular than wireline logging in Chikyu expeditions, because its advantages match theirs science targets. The advantages are followings. 1) LWD has more opportunities for measurement in unstable borehole, such as in the series of Nankai trough drilling expeditions. 2) LWD realtime data allows us to make realtime interpretation and operational decision. Realtime interpretation was required to set obsevartory at the properposition. 3) LWD before coring allows us to make a strategy of spot coring.We can design coring intervals for our interest and core length to improve core recovery.Riser drilling brings us merits for logging. One is hole stability (good hole condition) and the other is the use of large diameter tools. Controled drilling mud in riser drilling system prevent mud invasion to formation and mitigates collapse of borehole wall. They reduce the risk of tool stack and improve data quality. Large diameter of riser pipe enhances variation of tool seizes. A couple of new tools were used for new measurement and improvement of the data quality. For example, SonicScanner (trademark of Schulumberger) successfully measured compressional and share velocity in very low velocities at the soft sediment, where it has been difficult to measure them with conventional DSI tool (Exp319). The stress and pore pressure in the borehole were measured with the wireline logging tool, (Schlumberger MDT). The single probe tool enable to measure temporal formation fluid pressure. The double packer tool enable to fracture test by sealing and pumping in the

Investigated conductive fracture in the granitic rocks by flow-meter logging

International Nuclear Information System (INIS)

Ogata, Nobuhisa; Koide, Kaoru; Takeichi, Atsushi

1997-01-01

Test of the use of a measurement technique for the hydraulic conductivity of geological structures which act as flow paths or are impermeable to groundwater flow. In order to prove the value of flow-meter logging as an in-situ technique for detecting conductive fractures in granitic rocks, the method has been applied to a borehole near the Tono uranium mine, Gifu, Japan. This study in involved with detecting a conductive fracture and calculating the hydraulic conductivities. The results were as follows: (1) In a zone of groundwater inflow into the borehole, the hydraulic conductivity was calculated to be of the order of the 10 -3 - 10 -4 (cm/sec) from flow-meter logging. This value agreed with the results of a in-situ borehole permeability test carried out with a similar depth interval. (2) The study showed that flow-meter logging is effective for detecting the distribution of high conductivity fractures and calculating the hydraulic conductivity. (author)

Summary of geoscience work at the AECL research site near Atikokan, Ontario

International Nuclear Information System (INIS)

Stone, D.

1984-03-01

Since 1979 June, geolgical, geophysical and hydro-geological investigations have been conducted at Research Area 4 north of Atikokan, Ontario as part of the Canadian Nuclear Fuel Waste Management Program. Composition, shape and internal structure of the Eye-Dashwa pluton were the subjects of regional field studies. Detailed research concentrated on the detection and characterization of surface and subsurface fractures within a 400-m x 800-m grid area, where five boreholes were drilled to depths of between 200 m and 1100 m. Fracture zones in the area were readily detected by surface mapping, ground very low frequency electromagnetic (VLF-EM) surveys and borehole logging. Borehole logs, downhole tube-wave seismic surveys, and thermal and television logging were successful in detecting open fractures in boreholes

Pulsed neutron generator for logging

International Nuclear Information System (INIS)

Thibideau, F.D.

1977-01-01

A pulsed neutron generator for uranium logging is described. This generator is one component of a prototype uranium logging probe which is being developed by SLA to detect, and assay, uranium by borehole logging. The logging method is based on the measurement of epithermal neutrons resulting from the prompt fissioning of uranium from a pulsed source of 17.6 MeV neutrons. An objective of the prototype probe was that its diameter not exceed 2.75 inches, which would allow its use in conventional rotary drill holes of 4.75-inch diameter. This restriction limited the generator to a maximum 2.375-inch diameter. The performance requirements for the neutron generator specified that it operate with a nominal output of 5 x 10 6 neutrons/pulse at up to 100 pulses/second for a one-hour period. The development of a neutron generator meeting the preliminary design goals was completed and two prototype models were delivered to SLA. These two generators have been used by SLA to log a number of boreholes in field evaluation of the probe. The results of the field evaluations have led to the recommendation of several changes to improve the probe's operation. Some of these changes will require additional development effort on the neutron generator. It is expected that this work will be performed during 1977. The design and operation of the first prototype neutron generators is described

Geophysical logging and hydrologic testing of deep basalt flows in the Rattlesnake Hills Well Number One

International Nuclear Information System (INIS)

Gephart, R.E.; Eddy, P.A.; Deju, R.A.

1979-01-01

Geophysical logging and hydrologic testing were conducted in the Rattlesnake Hills Well Number One located along the western boundary of the Hanford Site in south-central Washington. Three-dimensional velocity, Seisviewer and caliper logging were completed across 2,000 feet of basalt rock within the Wanapum and Grande Ronde formations. Drillstem testing focused along a 250-foot interval of the Grande Ronde Formation. Individual high- (approx. 2.7-2.9 grams per cubic centimeter) and low-density (approx. 2.3-2.6 grams per cubic centimeter) basalt zones within the Wanapum Formation are generally less than 50 feet thick. Within the estimated thickness of the Grande Ronde Formation, 85 percent of the low-density zones are less than 50 feet thick, compared to 55 percent of those of higher density. The Grande Ronde Formation has 13 high-density zones varying in thickness from 51 to 230 feet. Logging data suggest the thicknesses of low-density are independent of the thicknesses of the associated and underlying higher density columnar basalts. Eleven drillstem tests were conducted across selected intervals within the Grande Ronde Formation. Hydraulic conductivity values calculated for the low-density basalt zones ranged between 1.7 x 10 -7 and 3.8 x 10 -9 centimeters per second; those for high-density zones were between 1.1 x 10 -8 and 4.7 x 10 -9 centimeters per second

Log response of ultrasonic imaging and its significance for deep mineral prospecting of scientific drilling borehole-2 in Nanling district, China

International Nuclear Information System (INIS)

Xiao, Kun; Zou, Changchun; Xiang, Biao; Yue, Xuyuan; Zhou, Xinpeng; Li, Jianguo; Zhao, Bin

2014-01-01

The hole NLSD-2, one of the deepest scientific drilling projects in the metallic ore districts of China, is the second scientific drilling deep hole in the Nanling district. Its ultimate depth is 2012.12 m. This hole was created through the implementation of continuous coring, and the measuring of a variety of geophysical well logging methods was performed over the course of the drilling process. This paper analyzes the characteristic responses of the fracture and fractured zone by ultrasonic imaging log data, and characterizes various rules of fracture parameters which change according to drilling depth. It then discusses the denotative meaning of the log results of polymetallic mineralization layers. The formation fractures develop most readily in a depth of 100∼200 m, 600∼850 m and 1450∼1550 m of the hole NLSD-2, and high angle fractures develop most prominently. The strike direction of the fractures is mainly NW-SE, reflecting the orientation of maximum horizontal principal stress. For the polymetallic mineralization layer that occurred in the fractured zone, the characteristic response of ultrasonic imaging log is a wide dark zone, and the characteristic responses of conventional logs displayed high polarizability, high density, high acoustic velocity and low resistivity. All the main polymetallic mineralization layers are developed in fractures or fractured zones, and the fractures and fractured zones can be identified by an ultrasonic imaging log, thus the log results indirectly indicate the occurrence of polymetallic mineralization layers. Additionally, the relationship between the dip direction of fractures and the well deviation provides guidance for straightening of the drilling hole. (paper)

Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

Energy Technology Data Exchange (ETDEWEB)

Oliver, H.W. [Geological Survey, Menlo Park, CA (USA); Hardin, E.L. [Science Applications International Corp., Las Vegas, NV (USA); Nelson, P.H. [Geological Survey, Denver, CO (USA)] [eds.

1990-07-01

This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs.

Status of data, major results, and plans for geophysical activities, Yucca Mountain Project

International Nuclear Information System (INIS)

Oliver, H.W.; Hardin, E.L.; Nelson, P.H.

1990-07-01

This report describes past and planned geophysical activities associated with the Yucca Mountain Project and is intended to serve as a starting point for integration of geophysical activities. This report relates past results to site characterization plans, as presented in the Yucca Mountain Site Characterization Plan (SCP). This report discusses seismic exploration, potential field methods, geoelectrical methods, teleseismic data collection and velocity structural modeling, and remote sensing. This report discusses surface-based, airborne, borehole, surface-to-borehole, crosshole, and Exploratory Shaft Facility-related activities. The data described in this paper, and the publications discussed, have been selected based on several considerations; location with respect to Yucca Mountain, whether the success or failure of geophysical data is important to future activities, elucidation of features of interest, and judgment as to the likelihood that the method will produce information that is important for site characterization. 65 refs., 19 figs., 12 tabs

Geophysical methods for determining the geotechnical engineering properties of earth materials.

Science.gov (United States)

2010-03-01

Surface and borehole geophysical methods exist to measure in-situ properties and structural : characteristics of earth materials. Application of such methods has demonstrated cost savings through : reduced design uncertainty and lower investigation c...

Borehole temperature variability at Hoher Sonnblick, Austria

Science.gov (United States)

Heinrich, Georg; Schöner, Wolfgang; Prinz, Rainer; Pfeiler, Stefan; Reisenhofer, Stefan; Riedl, Claudia

2016-04-01

The overarching aim of the project 'Atmosphere - permafrost relationship in the Austrian Alps - atmospheric extreme events and their relevance for the mean state of the active layer (ATMOperm)' is to improve the understanding of the impacts of atmospheric extreme events on the thermal state of the active layer using a combined measurement and modeling approach as the basis for a long-term monitoring strategy. For this purpose, the Sonnblick Observatory at the summit of Hoher Sonnblick (3106 m.a.s.l) is particularly well-suited due to its comprehensive long-term atmospheric and permafrost monitoring network (i.a. three 20 m deep boreholes since 2007). In ATMOperm, a robust and accurate permanent monitoring of active layer thickness at Hoher Sonnblick will be set up using innovative monitoring approaches by automated electrical resistivity tomography (ERT). The ERT monitoring is further supplemented by additional geophysical measurements such as ground penetrating radar, refraction seismic, electromagnetic induction and transient electromagnetics in order to optimally complement the gained ERT information. On the other hand, atmospheric energy fluxes over permafrost ground and their impact on the thermal state of permafrost and active layer thickness with a particular focus on atmospheric extreme events will be investigated based on physically-based permafrost modeling. For model evaluation, the borehole temperature records will play a key role and, therefore, an in-depth quality control of the borehole temperatures is an important prerequisite. In this study we will show preliminary results regarding the borehole temperature variability at Hoher Sonnblick with focus on the active layer. The borehole temperatures will be related to specific atmospheric conditions using the rich data set of atmospheric measurements of the site in order to detect potential errors in the borehole temperature measurements. Furthermore, we will evaluate the potential of filling gaps in

Geomicrobial Optical Logging Detectors (GOLD)

Science.gov (United States)

Bramall, N. E.; Stoker, C. R.; Price, P. B.; Coates, J. D.; Allamandola, L. J.; Mattioda, A. L.

2008-12-01

We will present concepts for downhole instrumentation that could be used in the Deep Underground Science and Engineering Laboratory (DUSEL). We envision optical borehole-logging instruments that could monitor bacterial concentration, mineralogy, aromatic organics, temperature and oxygen concentration, allowing for the in situ monitoring of time-dependent microbial and short-scale geologic processes and provide valuable in situ data on stratigraphy to supplement core analyses, especially where instances of missing or damaged core sections make such studies difficult. Incorporated into these instruments will be a sampling/inoculation tool to allow for the recovery and/or manipulation of particularly interesting sections of the borehole wall for further study, enabling a series of microbiological studies. The borehole tools we will develop revolve around key emerging technologies and methods, some of which are briefly described below: 1) Autofluorescence Spectroscopy: Building on past instruments, we will develop a new borehole logger that searches for microbial life and organics using fluorescence spectroscopy. Many important organic compounds (e.g. PAHs) and biomolecules (e.g. aromatic amino acids, proteins, methanogenic coenzymes) fluoresce when excited with ultraviolet and visible light. Through the careful selection of excitation wavelength(s) and temporal gating parameters, a borehole logging instrument can detect and differentiate between these different compounds and the mineral matrix in which they exist. 2) Raman Spectroscopy: Though less sensitive than fluorescence spectroscopy, Raman spectroscopy is more definitive: it can provide important mineral phase distribution/proportions and other chemical data enabling studies of mineralogy and microbe-mineral interactions (when combined with fluorescence). 3) Borehole Camera: Imaging of the borehole wall with extended information in the UV, visible, and NIR for a more informative view can provide a lot of insight

Determination of the rock clayiness from statistically standardized gamma-logging diagrams

International Nuclear Information System (INIS)

Kholodilov, V.V.

1975-01-01

Statistical standardization (using mathematical expectancy and dispersion) was done on gamma-logging diagrams made from 43 boreholes in producing strata of mid Jurassic and lower Cretaceous deposits in the Dagestan Plain. The material of the deposits is chiefly sands and aleurites containing 5 to 45% clay. The dependence of the standard deviation of the gamma-log curves on the clayiness of the rocks was determined at intervals of 400 and 300 meters. The intervals were selected by considering the borehole depth. The coefficients of correlation were 0.87 and 0.86, respectively

Methods and apparatus for environmental correction of thermal neutron logs

International Nuclear Information System (INIS)

Preeg, W.E.; Scott, H.D.

1983-01-01

An on-line environmentally-corrected measurement of the thermal neutron decay time (tau) of an earth formation traversed by a borehole is provided in a two-detector, pulsed neutron logging tool, by measuring tau at each detector and combining the two tau measurements in accordance with a previously established empirical relationship of the general form: tau = tausub(F) +A(tausub(F) + tausub(N)B) + C, where tausub(F) and tausub(N) are the tau measurements at the far-spaced and near-spaced detectors, respectively, A is a correction coefficient for borehole capture cross section effects, B is a correction coefficient for neutron diffusion effects, and C is a constant related to parameters of the logging tool. Preferred numerical values of A, B and C are disclosed, and a relationship for more accurately approximating the A term to specific borehole conditions. (author)

Exploration and grade control neutron logging

International Nuclear Information System (INIS)

Eisler, P.L.

1982-01-01

Techniques used in neutron logging in boreholes are discussed. They include the application of neutron probes to porosity measurements, to lithological determinations based on macroscopic cross-section measurements and measurements of the concentration of chemical constituents in rocks and ores

Geophysical logging and imaging of shallow drillholes ONK-PP262 and ONK-274 at Olkiluoto in 2010

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2011-11-01

Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of shallow drillholes ONK-PP262 and ONK-PP274 at ONKALO in the investigation niche ONK-TKU-4 (Hydco) in May and in December 2010. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

Geophysical logging and imaging of characterisation drillholes ONK-KR13, ONK-KR14 and ONK-KR15

International Nuclear Information System (INIS)

Tarvainen, A.-M.

2011-08-01

Suomen Malmi Oy conducted geophysical drillhole logging as well as optical and acoustic imaging of drillholes ONK-KR13, ONK-KR14 and ONK-KR15 at ONKALO in June-July 2010 and in March 2011. The survey is a part of Posiva Oy's detailed investigation program for the final disposal of spent nuclear fuel. The assignment included the field work and data processing. The report describes field operation, equipment as well as processing procedures and shows the obtained results and an analysis of their quality in the appendices. The raw and processed data are delivered digitally in WellCAD, PDF and Excel format. (orig.)

Analysis of groundwater from deep boreholes in Gideaa

International Nuclear Information System (INIS)

Laurent, S.

1983-03-01

Groundwaters from two boreholes in granitic rock at an ivestigation site in Gideaa has been sampled and analysed. This is part of a larger program of geological, geophysical and hydrogeological investigations aimed at finding a suitable site for a high level radioactive waste respository. Five water-bearing levels in each borehole down to the deepest at about 500 m in the first and about 600 m in the second borehole were selected. Prior to sampling, the waterbearing level is isolated between packer sleeves. The water is then pumped to the surface where sensitive parameters such as redox potential, pH, sulphide and oxygen content are measured electrochemically on the flowing water in a system isolated from the air. Water, filter and gas samples are sent to several laboratories for further analysis. The present report is a presentation of the groundwater analysis. The reliability of the results is discussed but there is no evaluation relation to geology and hydrogeology. This report presents the basic results from the groundwater analyses to be further evaluated by experts in different fields. (Forf)

Mapping possible flowpaths of contaminants through surface and cross-borehole spectral time-domain induced polarization

DEFF Research Database (Denmark)

Bording, Thue Sylvester; Fiandaca, Gianluca; Maurya, Pradip Kumar

Traditional methods for mapping possible flowpaths of contaminants in sedimentary environments by boreholes may often be insufficient. Additional information may be acquired by geophysical methods. In the present study, cross-borehole and surface measurements were performed using time-domain indu......-domain induced polarization (TDIP). After measurements the entire test site was dug out, and the geology was described. A 2D spectral inversion of the combined dataset is presented, which is in great correspondence with the observed geology....

The Device for Communication in the Tool for Measurement in Boreholes

Directory of Open Access Journals (Sweden)

Miloš Slankamenac

2005-10-01

Full Text Available In this paper an implementation and test of the device for communication between Telemetry system and Surface unit with the tool for measurement of pipe diameter, fluid velocity and direction of flow in the borehole (Calliper-Fullbore Flowmeter - CFF are presented. This communication is done according to SIPLOS (Simultaneous Production Logging String protocol and it is used by Hotwell company [1] as a part of a larger system for borehole investigations.

Comparative study of gamma-ray logging and radiometric core assay of boreholes in block-I of Tummalapalle area, Cuddapah District, Andhra Pradesh using statistical methods

International Nuclear Information System (INIS)

Sreenivasa Reddy, M.; Mandal, G.; Bhaumik, B.K.

2012-01-01

A comparative study has been carried out between gamma-ray logging and radiometric core assay data of boreholes in Block-I of Tummalapalle area, South Cuddapah Basin, Andhra Pradesh using statistical methods. The product of average grade (in %eU 3 O 8 ) and thickness (in m) of uranium mineralization has been used for this purpose. The outcome of statistical analysis revealed a strong relation between gamma-ray logging and radiometric core assay data. Slope of the line is close to 1.0 and intercept is not different from 0.0. It ensures homogeneity of uranium ore distribution in the host rock. The calculated value from t-test is well within the limit and ensures the negligibility in the difference of means. This indicates that either of the data can be used for ore reserve calculation. (author)

Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA

Science.gov (United States)

Yang, Qiang; Culbertson, Charles W.; Nielsen, Martha G.; Schalk, Charles W.; Johnson, Carole D.; Marvinney, Robert G.; Stute, Martin; Zheng, Yan

2014-01-01

To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 g/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ18O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater.

Programs and procedures for assessing quality of spectral gamma-ray borehole data for the UGTA

International Nuclear Information System (INIS)

Conaway, J.G.

1998-01-01

This report describes the procedures and computer programs used to process spectral gamma-ray borehole logging data in the UGTA (UnderGround Test Area) program at the NTS (Nevada Test Site) to assess data quality. These programs and procedures were used to analyze data from five boreholes in the UGTA program. Development of these computer programs and procedures required considerable effort and the primary purpose of this report is to provide continuity with future activities related to spectral gamma-ray borehole logging in the UGTA program. This is especially important because of the long time interval between cessation of logging in April, 1996 and the next round of activity, which has not yet occurred. This report should also be useful if any quality control issues arise regarding past or forthcoming spectral gamma-ray log analyses. In the characterization work underway at the Nevada Test Site Underground Test Area, the logging contractor, Western Atlas, agreed to identify five artificial nuclides based on their gamma-ray signatures. Those nuclides are 60 Co, 106 Ru, 125 Sb, 134 Cs, and 137 Cs. In the case of 106 Ru, which is not a gamma emitter, any detected gamma rays come from the daughter nuclide 106 Rh which has a half-life of 30 s. With such a short half-life, 106 Rh can be considered to be in equilibrium with 106 Ru under most conditions so the result is the same as if the gamma rays were emitted by the 106 Ru. The Western Atlas spectral gamma-ray curve plots from a given borehole present detailed qualitative information on the apparent distribution of natural and artificial nuclides with depth in the borehole. The computer programs and procedures described in this report were used to provide a quality analysis of the contractor's processed data and to work with the contractor to validate and/or refine their existing automatic processing. This was done using a procedure that was developed and tested successfully in earlier work at the NTS; the revised

Vadose zone monitoring plan using geophysical nuclear logging for radionuclides discharged to Hanford liquid waste disposal facilities

International Nuclear Information System (INIS)

Price, R.K.

1995-11-01

During plutonium production at Hanford, large quantities of hazardous and radioactive liquid effluent waste have been discharged to the subsurface (vadose zone). These discharges at over 330 liquid effluent disposal facilities (ie. cribs, ditches, and ponds) account for over 3,000,000 curies of radioactive waste released into the subsurface. It is estimated that 10% of the contaminants have reached the groundwater in many places. Continuing migration may further impact groundwater quality in the future. Through the RCRA Operational Monitoring Program, a Radionuclide Logging System (RLS) has been obtained by Hanford Technical Services (HTS) and enhanced to measure the distribution of contaminants and monitor radionuclide movement in existing groundwater and vadose zone boreholes. Approximately 100 wells are logged by HTS each year in this program. In some cases, movement has been observed years after discharges were terminated. A similar program is in place to monitor the vadose zone at the Tank Farms. This monitoring plan describes Hanford Programs for monitoring the movement of radioactive contamination in the vadose zone. Program background, drivers, and strategy are presented. The objective of this program is to ensure that DOE-RL is aware of any migration of contaminants in the vadose zone, such that groundwater can be protected and early actions can be taken as needed

Geophysical investigations on the Vaalputs radioactive waste disposal site in the Republic of South Africa

International Nuclear Information System (INIS)

Andersen, N.J.B.; Faurie, J.N.; Fernandez, L.M.

1986-01-01

As the rocks of the Namaqualand Metamorphic Complex are sand-covered in the area of interest, extensive airborne and ground geophysical surveys were undertaken to assist with the evaluation of the regional and local geology, as well as to locate and avoid possible mineralization. A medium sensitivity aeromagnetic survey and an airborne INPUT survey were used to locate potentially mineralized kimberlite and noritoid intrusions. After airborne detection, these targets were followed up on the ground using electromagnetic and resistivity techniques. Subsequent drilling proved them to be unmineralized. A thermal infrared line-scan survey was used in conjunction with the aeromagnetics to evaluate the structural geology and assist with the location of groundwater. Continuous seismics refraction profiling was used to locate an area of rippable overburden (i.e. having a seismic velocity of less than 1 500 m/s) and depth greater than 10 m for the excavation of the low-level waste trenches. All boreholes were radiometrically logged. Since the Vaalputs area is entirely sand-covered it was essential to use geophysical techniques to evaluate the subsurface geology, and to avoid placing the facility in an area of economic mineralization

NNWSI [Nevada Nuclear Waste Storage Investigations] hole histories, USW UZ-1, UE-25 UZ No. 4, UE-25 UZ No. 5, USW UZ-6, USW UZ-6s, USW UZ-7, USW UZ-8, USW UZ-13

International Nuclear Information System (INIS)

1987-04-01

This report is a compilation of data from eight exploratory boreholes drilled to help characterize the geology and hydrology of the unsaturated zone. The eight holes were drilled in Area 25 of the Nevada Test Site and in Bureau of Land Management land adjacent to the Nevada Test Site. Data presented in the hole histories include all locations, daily activities, review of hole conditions, geophysical log lists and microfiche copies of the geophysical logs

Geophysical and topographic expression of early Mesozoic grand cycles of the Milankovitch band

Science.gov (United States)

Olsen, P. E.; Reynolds, D. J.; Goldberg, D.; Kent, D. V.; Whiteside, J. H.

2012-12-01

Grand cycles are orbitally controlled insolation cycles that have frequencies significantly lower than the precession-related ~1/100ky "eccentricity" cycles (1). We have previously shown that variations in sedimentary facies and δ13C interpreted in terms of lake level changes in Triassic-Jurassic cores of the Newark Basin Coring Project (NBCP) of eastern North America track predicted orbital cycles related to precession (2,3). In addition to the usual ~1/20ky and "spilt" ~1/100ky cycles, Grand Cycles with frequencies of 1/405ky (g2-g5) are very prominent and cycles with much lower frequency of ~1/1.8m.y. representing the g4-g3 frequency are present. The latter differs from the present frequency of ~1/2.4m.y. because of the chaotic diffusion of planetary orbits (4). Wavelet analysis of borehole geophysical logs from the NBCP show the same basic frequencies as do sedimentary facies. The high-frequency precession-related cycles as seen in natural gamma and sonic velocity logs are strikingly complimentary to visually identified sedimentary facies patterns because the former tend to show the most striking cyclicity where the sedimentary facies pattern are the most muted. The 1/405ky cycles are also very prominent; but other grand cycles, while detectable, are distorted by the necessary detrending of each of the seven borehole records that comprise the NBCP composite (cf. 5,6). Simple detrending procedures leave a low-frequency residue and more complex models prejudge the low frequencies we are trying to detect. This emphasizes the importance of the facies interpretations that requires no detrending, and clear understanding of the meaning of the geophysical environmental proxies. As might be expected from the seismic velocity logs, synthetic seismic traces generated from the borehole data of the NBCP show the grand cycles. When tied to very long industry exploratory borehole records from the Newark basin, themselves tied to seismic lies, both the 1/405ky (g2-g5) and ~1

A comparison between elemental logs and core data

International Nuclear Information System (INIS)

Kerr, S.A.; Grau, J.A.; Schweitzer, J.S.

1992-01-01

Neutron-induced gamma-ray spectroscopy, of prompt capture and delayed activation, together with natural gamma-ray measurements, provides a borehole elemental analysis to characterize rock matrix composition. This study involved extensive core and log data in two wells. One well was drilled with a barite-weighted oil-based mud through a shallow marine sand. The other was drilled with fresh water-based mud through a channel sand, mudstone sequence overlying limestone. The results illustrate the importance of a suitable core sampling strategy and the problems associated with matching core to log data. Possible inaccuracies from the modelling of Ca-, Fe- and S-bearing minerals have been determined. A method for correcting the total measured aluminium concentration for that due to the borehole mud has been successfully tested against aluminium concentrations measured in the cleaned core samples. Estimates of the overall accuracy and precision of the elemental logging concentrations are obtained by comparing the log results with those obtained from the laboratory core analysis. A comprehensive core elemental analysis can also provide useful insight into the way other logs, such as the photoelectric factor or formation thermal neutron macroscopic absorption cross section, are influenced by minor and trace elements. Differences between calculated values from elemental logs and measured macroscopic parameters provide additional data for a more detailed understanding of the rock properties. (Author)

High resolution gamma spectroscopy well logging system

International Nuclear Information System (INIS)

Giles, J.R.; Dooley, K.J.

1997-01-01

A Gamma Spectroscopy Logging System (GSLS) has been developed to study sub-surface radionuclide contamination. The absolute counting efficiencies of the GSLS detectors were determined using cylindrical reference sources. More complex borehole geometries were modeled using commercially available shielding software and correction factors were developed based on relative gamma-ray fluence rates. Examination of varying porosity and moisture content showed that as porosity increases, and as the formation saturation ratio decreases, relative gamma-ray fluence rates increase linearly for all energies. Correction factors for iron and water cylindrical shields were found to agree well with correction factors determined during previous studies allowing for the development of correction factors for type-304 stainless steel and low-carbon steel casings. Regression analyses of correction factor data produced equations for determining correction factors applicable to spectral gamma-ray well logs acquired under non-standard borehole conditions

Electrical and gamma-ray logging in Gondwana and Tertiary coal fields of India

International Nuclear Information System (INIS)

Kayal, J.R.

1979-01-01

Electrical and gamma-ray logging have been very useful for identification and accurate determination of depth and thickness of coal seams in Gondwana and Tertiary coal fields of India. The characteristic resistance/resistivity peaks of coal seams in a particular area have been correlated, thus providing a picture of the subsurface structure. Physico-chemical properties of layers or sections of coal seams are responsive to electrical logs. Gamma-ray logs are found to be very useful for correlation and have sometimes been the only logs used in cased and dry boreholes for detection of coal seams. Under favourable conditions a single-point resistance log reveals a detailed picture of the formations and picks up thin coal seams as well as thin shale bands within the coal seam. But in some cases it fails to differentiate between coal and sandstone beds in spite of high contrast in true resistivities. Multi-electrode long-normal and lateral logs are found to be more useful in differentiating such formations because of higher penetration in this system. Long-normal and lateral curves can also be used to determine true resisvity of the formation. But long normal logs cannot pick up thin coal bands and/or thin shale partings within the coal seam because of the 'adjacent bed effect'. Gamma-ray logging can be done in both cased and uncased bore-holes or even in a dry borehole but its resolution for shaly coal or thin coal is not sufficient. Combined study has been found to yield the best results. (Auth.)

Proceedings of a workshop on geophysical and related geoscientific research at Chalk River, Ontario

International Nuclear Information System (INIS)

Thomas, M.D.; Dixon, D.F.

1989-10-01

A large part of the Canadian Nuclear Fuel Waste Management Program is geoscience research and development aimed at obtaining information to quantify the transport of radionuclides through the geosphere and at determining the geotechnical properties required for disposal vault design. The geosphere at potential disposal sites is characterized in part by the use of remote sensing (geophysical) methods. In 1977 public concern about the disposal of radioactive waste resulted in field work being restricted to the site of Chalk River Nuclear Laboratories, which was used to develop, evaluate and compare various techniques in order to optimize the methods for obtaining geoscience information. Methods tested at Chalk River are to be applied at other research sites. Most investigations have been carried out around Maskinonge Lake, using about thirty boreholes sink into bedrock. The boreholes provide subsurface geological information that can be used as a reference to compare the responses of various geophysical methods and equipment. Regional studies, including airborne geophysical surveys, have also been conducted. The 25 papers presented at this workshop provide comprehensive documentation of the most significant results of geophysical studies. The workshop also provided an evaluation of geophysical techniques and their utility to the Nuclear Fuel Waste Management Program

Pulsed neutron porosity logging system

International Nuclear Information System (INIS)

Smith, H.D. Jr.; Smith, M.P.; Schultz, W.E.

1978-01-01

An improved pulsed neutron porosity logging system is provided in the present invention. A logging tool provided with a 14 MeV pulsed neutron source, an epithermal neutron detector, and a fast neutron detector is moved through a borehole. Repetitive bursts of neutrons irradiate the earth formations and, during the bursts, the fast neutron population is sampled. During the interval between bursts the epithermal neutron population is sampled along with background gamma radiation due to lingering thermal neutrons. The fast and epithermal neutron population measurements are combined to provide a measurement of formation porosity

Response transforms from comparative study of commercial pulsed-neutron-capture logging systems

International Nuclear Information System (INIS)

Salaita, G.N.

1992-01-01

This paper reports that three generations of Schlumberger's Thermal Decay Time (TDT SM ) logging devices - viz., TDT-K, TDT-M, and TDT-P - along with an Atlas Wireline PDK-100 SM system were run in a Saudi Aramco well. The wellbore (8 1/2 in. with 7-in. casing) penetrated a sequence of clean sand, shaly sand, and shale streaks as exhibited by the openhole natural gamma ray log. The initial wellbore fluid was diesel. The fluid was then changed to brines of 42,000 and 176,000 ppm NaCl, respectively. Three repeat passes at a logging speed of 900 ft/hr were obtained by each device for each borehole liquid. As a result of this extensive comparative study, a set of departure curves and mathematical transforms was developed primarily for standardizing the various Schlumberger tools to a common reference logging system and/or borehole environment. The transforms were used beneficially to determine residual oil saturation (ROS) from time-lapse logs in a Saudi Aramco reservoir

Towards a geophysical decision-support system for monitoring and managing unstable slopes

Science.gov (United States)

Chambers, J. E.; Meldrum, P.; Wilkinson, P. B.; Uhlemann, S.; Swift, R. T.; Inauen, C.; Gunn, D.; Kuras, O.; Whiteley, J.; Kendall, J. M.

2017-12-01

Conventional approaches for condition monitoring, such as walk over surveys, remote sensing or intrusive sampling, are often inadequate for predicting instabilities in natural and engineered slopes. Surface observations cannot detect the subsurface precursors to failure events; instead they can only identify failure once it has begun. On the other hand, intrusive investigations using boreholes only sample a very small volume of ground and hence small scale deterioration process in heterogeneous ground conditions can easily be missed. It is increasingly being recognised that geophysical techniques can complement conventional approaches by providing spatial subsurface information. Here we describe the development and testing of a new geophysical slope monitoring system. It is built around low-cost electrical resistivity tomography instrumentation, combined with integrated geotechnical logging capability, and coupled with data telemetry. An automated data processing and analysis workflow is being developed to streamline information delivery. The development of this approach has provided the basis of a decision-support tool for monitoring and managing unstable slopes. The hardware component of the system has been operational at a number of field sites associated with a range of natural and engineered slopes for up to two years. We report on the monitoring results from these sites, discuss the practicalities of installing and maintaining long-term geophysical monitoring infrastructure, and consider the requirements of a fully automated data processing and analysis workflow. We propose that the result of this development work is a practical decision-support tool that can provide near-real-time information relating to the internal condition of problematic slopes.

Experimental Measurement of In Situ Stress

Science.gov (United States)

Tibbo, Maria; Milkereit, Bernd; Nasseri, Farzine; Schmitt, Douglas; Young, Paul

2016-04-01

The World Stress Map data is determined by stress indicators including earthquake focal mechanisms, in situ measurement in mining, oil and gas boreholes as well as the borehole cores, and geologic data. Unfortunately, these measurements are not only infrequent but sometimes infeasible, and do not provide nearly enough data points with high accuracy to correctly infer stress fields in deep mines around the world. Improvements in stress measurements of Earth's crust is fundamental to several industries such as oil and gas, mining, nuclear waste management, and enhanced geothermal systems. Quantifying the state of stress and the geophysical properties of different rock types is a major complication in geophysical monitoring of deep mines. Most stress measurement techniques involve either the boreholes or their cores, however these measurements usually only give stress along one axis, not the complete stress tensor. The goal of this project is to investigate a new method of acquiring a complete stress tensor of the in situ stress in the Earth's crust. This project is part of a comprehensive, exploration geophysical study in a deep, highly stressed mine located in Sudbury, Ontario, Canada, and focuses on two boreholes located in this mine. These boreholes are approximately 400 m long with NQ diameters and are located at depths of about 1300 - 1600 m and 1700 - 2000 m. Two borehole logging surveys were performed on both boreholes, October 2013 and July 2015, in order to perform a time-lapse analysis of the geophysical changes in the mine. These multi-parameter surveys include caliper, full waveform sonic, televiewer, chargeability (IP), and resistivity. Laboratory experiments have been performed on borehole core samples of varying geologies from each borehole. These experiments have measured the geophysical properties including elastic modulus, bulk modulus, P- and S-wave velocities, and density. The apparatus' used for this project are geophysical imaging cells capable

Computer method to detect and correct cycle skipping on sonic logs

International Nuclear Information System (INIS)

Muller, D.C.

1985-01-01

A simple but effective computer method has been developed to detect cycle skipping on sonic logs and to replace cycle skips with estimates of correct traveltimes. The method can be used to correct observed traveltime pairs from the transmitter to both receivers. The basis of the method is the linearity of a plot of theoretical traveltime from the transmitter to the first receiver versus theoretical traveltime from the transmitter to the second receiver. Theoretical traveltime pairs are calculated assuming that the sonic logging tool is centered in the borehole, that the borehole diameter is constant, that the borehole fluid velocity is constant, and that the formation is homogeneous. The plot is linear for the full range of possible formation-rock velocity. Plots of observed traveltime pairs from a sonic logging tool are also linear but have a large degree of scatter due to borehole rugosity, sharp boundaries exhibiting large velocity contrasts, and system measurement uncertainties. However, this scatter can be reduced to a level that is less than scatter due to cycle skipping, so that cycle skips may be detected and discarded or replaced with estimated values of traveltime. Advantages of the method are that it can be applied in real time, that it can be used with data collected by existing tools, that it only affects data that exhibit cycle skipping and leaves other data unchanged, and that a correction trace can be generated which shows where cycle skipping occurs and the amount of correction applied. The method has been successfully tested on sonic log data taken in two holes drilled at the Nevada Test Site, Nye County, Nevada

A Computer Program for Flow-Log Analysis of Single Holes (FLASH)

Science.gov (United States)

Day-Lewis, F. D.; Johnson, C.D.; Paillet, Frederick L.; Halford, K.J.

2011-01-01

A new computer program, FLASH (Flow-Log Analysis of Single Holes), is presented for the analysis of borehole vertical flow logs. The code is based on an analytical solution for steady-state multilayer radial flow to a borehole. The code includes options for (1) discrete fractures and (2) multilayer aquifers. Given vertical flow profiles collected under both ambient and stressed (pumping or injection) conditions, the user can estimate fracture (or layer) transmissivities and far-field hydraulic heads. FLASH is coded in Microsoft Excel with Visual Basic for Applications routines. The code supports manual and automated model calibration. ?? 2011, The Author(s). Ground Water ?? 2011, National Ground Water Association.

Time-Lapse Electrical Geophysical Monitoring of Amendment-Based Biostimulation.

Science.gov (United States)

Johnson, Timothy C; Versteeg, Roelof J; Day-Lewis, Frederick D; Major, William; Lane, John W

2015-01-01

Biostimulation is increasingly used to accelerate microbial remediation of recalcitrant groundwater contaminants. Effective application of biostimulation requires successful emplacement of amendment in the contaminant target zone. Verification of remediation performance requires postemplacement assessment and contaminant monitoring. Sampling-based approaches are expensive and provide low-density spatial and temporal information. Time-lapse electrical resistivity tomography (ERT) is an effective geophysical method for determining temporal changes in subsurface electrical conductivity. Because remedial amendments and biostimulation-related biogeochemical processes often change subsurface electrical conductivity, ERT can complement and enhance sampling-based approaches for assessing emplacement and monitoring biostimulation-based remediation. Field studies demonstrating the ability of time-lapse ERT to monitor amendment emplacement and behavior were performed during a biostimulation remediation effort conducted at the Department of Defense Reutilization and Marketing Office (DRMO) Yard, in Brandywine, Maryland, United States. Geochemical fluid sampling was used to calibrate a petrophysical relation in order to predict groundwater indicators of amendment distribution. The petrophysical relations were field validated by comparing predictions to sequestered fluid sample results, thus demonstrating the potential of electrical geophysics for quantitative assessment of amendment-related geochemical properties. Crosshole radar zero-offset profile and borehole geophysical logging were also performed to augment the data set and validate interpretation. In addition to delineating amendment transport in the first 10 months after emplacement, the time-lapse ERT results show later changes in bulk electrical properties interpreted as mineral precipitation. Results support the use of more cost-effective surface-based ERT in conjunction with limited field sampling to improve spatial

Large scale mapping of groundwater resources using a highly integrated set of tools

DEFF Research Database (Denmark)

Søndergaard, Verner; Auken, Esben; Christiansen, Anders Vest

large areas with information from an optimum number of new investigation boreholes, existing boreholes, logs and water samples to get an integrated and detailed description of the groundwater resources and their vulnerability.Development of more time efficient and airborne geophysical data acquisition...... platforms (e.g. SkyTEM) have made large-scale mapping attractive and affordable in the planning and administration of groundwater resources. The handling and optimized use of huge amounts of geophysical data covering large areas has also required a comprehensive database, where data can easily be stored...

Acoustic reflection log in transversely isotropic formations

Science.gov (United States)

Ronquillo Jarillo, G.; Markova, I.; Markov, M.

2018-01-01

We have calculated the waveforms of sonic reflection logging for a fluid-filled borehole located in a transversely isotropic rock. Calculations have been performed for an acoustic impulse source with the characteristic frequency of tens of kilohertz that is considerably less than the frequencies of acoustic borehole imaging tools. It is assumed that the borehole axis coincides with the axis of symmetry of the transversely isotropic rock. It was shown that the reflected wave was excited most efficiently at resonant frequencies. These frequencies are close to the frequencies of oscillations of a fluid column located in an absolutely rigid hollow cylinder. We have shown that the acoustic reverberation is controlled by the acoustic impedance of the rock Z = Vphρs for fixed parameters of the borehole fluid, where Vph is the velocity of horizontally propagating P-wave; ρs is the rock density. The methods of waveform processing to determine the parameters characterizing the reflected wave have been discussed.

Method and apparatus for nuclear logging making use of lithium detectors and equipment for gamma ray stripping; Fremgangsmaate og apparat til nuklear logging med bruk av litiummontasjer og anordning for gammastraalestripping

Energy Technology Data Exchange (ETDEWEB)

Perry, C.A.; Daigle, G.A.; Bruck, W.D. [and others

1998-05-11

The patent deals with a borehole logging tool where a pair of spaced-apart lithium detectors is lowered into a borehole traversing a sursurface formation. The formation is irradiated with bursts of neutrons, and the neutrons returning to the borehole are detected by thermal neutron detectors. The dieaway gamma ray spectra provide information on the formation porosity. A MWD system includes a programmable gain amplifier and gamma ray stripping means. 30 figs.

Spurious Additional Warming Reconstructed From Borehole Temperatures Corrected for the Effect of the Last Glacial Cycle

Science.gov (United States)

Šafanda, Jan

2018-03-01

Reconstructions of past ground surface temperature changes from temperature logs conducted in several hundred meter deep boreholes have proved to be a valuable independent source of information on climate variations over the last millennium. The reconstruction techniques have been evolving for more than two decades to extract optimally the climate signal of the last millennium contained in the temperature logs of different length performed in sites with different histories of the Last Glacial Cycle. This paper analyzes the method of the Last Glacial Cycle thermal effect removal from such borehole temperature profiles used by Beltrami et al. (2017, https://doi.org/10.1002/2016GL071317) in reconstructing the last 500 year history. I show that the reported results of additional warming in this period reconstructed from the corrected borehole data for North America are an artifact generated by the correction.

Delineation of areas having elevated electrical conductivity, orientation and characterization of bedrock fractures, and occurrence of groundwater discharge to surface water at the U.S. Environmental Protection Agency Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina

Science.gov (United States)

Chapman, Melinda J.; Huffman, Brad A.; McSwain, Kristen Bukowski

2015-07-16

During October 2012 through March 2013, the U.S. Geological Survey (USGS), in cooperation with the U.S. Environmental Protection Agency (EPA) Region 4, Superfund Section, conducted borehole geophysical logging, surface geophysical surveys, and water-quality profiling in selected wells and areas to characterize or delineate the extent of elevated subsurface electrical conductivity at the EPA Barite Hill/Nevada Goldfields Superfund site near McCormick, South Carolina. Elevated electrical conductivity measured at the site may be related to native rock materials, waste rock disposal areas used in past operations, and (or) groundwater having elevated dissolved solids (primarily metals and major ions) related to waste migration. Five shallow screened wells and four open-borehole bedrock wells were logged by using a suite of borehole tools, and downhole water-quality profiles were recorded in two additional wells. Well depths ranged from about 26 to 300 feet below land surface. Surface geophysical surveys based on frequency-domain electromagnetic and distributed temperature sensing (DTS) techniques were used to identify areas of elevated electrical conductivity (Earth materials and groundwater) and potential high dissolved solids in groundwater and surface water on land and in areas along the northern unnamed tributary at the site.

Connections between borehole geophysical parameters of the quality of cement raw materials

International Nuclear Information System (INIS)

Szabo, L.; Illes, A.

1978-01-01

The raw materials for the cement industry are prospected - according to the recommendations of national authorities - by geophysical methods, too. These include not the determination of the deposit boundary, but also an estimation of the quality of limestone and clay from the point of cement manufacture. No forerunners of such tests exist, so new methods were elaborated. After 12 years of site tests it was found that the correlation between laboratory quality tests and certain geophysical parameters of clay deposits is fair but less close in case of limestone deposits. (author)

Improving our understanding of the evolution of mountain belts via the Collisional Orogeny in the Scandinavian Caledonides (COSC) project: Results from seismic investigations and plans for the 2.5 km deep COSC-2 borehole

Science.gov (United States)

Juhlin, C.; Almqvist, B. S. G.; Buske, S.; Giese, R.; Hedin, P.; Lorenz, H.

2017-12-01

Mountain belts (orogens) have influenced, and do influence, geological processes and climatic conditions considerably, perhaps more than any other natural phenomenon. The Alpine-Himalayan mountain belt is the prime example of a collisional orogen today. However, research in an active orogen is mostly constrained to observe and interpret the expression of processes at the surface, while the driving processes act at depth, often at mid-crustal levels (20 km) and deeper. About 440 million years ago, an orogen comparable in dimension and tectonic setting to today's Alpine-Himalayan orogen was developing in what is western Scandinavia today. Since then, erosion has removed much of the overburden and exposed the deep interior of the orogen, facilitating direct observation of rocks that are deep in the crust in modern orogens. In the COSC project we study how large rock volumes (allochthons) were transported during the collision of two continents and the associated deformation. The emplacement of high-grade metamorphic allochthons during orogeny has been the focus of COSC-1 research, centered on a 2.5 km deep fully cored borehole drilled in the summer of 2014 through the lower part of the high-grade Seve Nappe Complex near the town of Åre in western Sweden. The planned COSC-2 borehole (also fully cored to 2.5 km) will complement the COSC-1 borehole and allow a 5 km deep tectonostratigraphic column of the Caledonides to be constructed. The rock volume in the proximity of the COSC-2 borehole will be imaged with a combination of very-high and high-resolution geophysical experiments, such as a combination of high frequency seismics; zero offset and walk-away vertical seismic profiling (VSP); and a sparse 3D coverage around the drill site combined with 2D seismic profiles of several kilometers length in different directions. Downhole geophysical logging will provide additional information on the in-situ rock physical properties. Data from surface surveys will be calibrated

Rock stress orientation measurements using induced thermal spalling in slim boreholes

International Nuclear Information System (INIS)

Hakami, Eva

2011-05-01

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

Rock stress orientation measurements using induced thermal spalling in slim boreholes

Energy Technology Data Exchange (ETDEWEB)

Hakami, Eva [Geosigma AB, Uppsala (Sweden)

2011-05-15

In the planning and design of a future underground storage for nuclear waste based on the KBS-3 method, one of the aims is to optimize the layout of deposition tunnels such that the rock stresses on the boundaries of deposition holes are minimized. Previous experiences from heating of larger scale boreholes at the Aespoe Hard Rock Laboratory (AHRL) gave rise to the idea that induced borehole breakouts using thermal loading in smaller diameter boreholes, could be a possible way of determining the stress orientation. Two pilot experiments were performed, one at the Aespoe Hard Rock Laboratory and one at ONKALO research site in Finland. An acoustic televiewer logger was used to measure the detailed geometrical condition of the borehole before and after heating periods. The acoustic televiewer gives a value for each 0.7 mm large pixel size around the borehole periphery. The results from the loggers are presented as images of the borehole wall, and as curves for the maximum, mean and minimum values at each depth. Any changes in the borehole wall geometry may thus be easily detected by comparisons of the logging result images. In addition, using an optical borehole televiewer a good and detailed realistic colour picture of the borehole wall is obtained. From these images the character of the spalls identified may be evaluated further. The heating was performed in a 4 m long section, using a heating cable centred in an 8 m deep vertical borehole, drilled from the floor of the tunnels. For the borehole in the Q-tunnel of AHRL the results from the loggings of the borehole before the heating revealed that breakouts existed even before this pilot test due to previous heating experiments at the site (CAPS). Quite consistent orientation and the typical shape of small breakouts were observed. After the heating the spalling increased slightly at the same locations and a new spalling location also developed at a deeper location in the borehole. At ONKALO three very small changes

In-situ fracture mapping using geotomography and brine tracers

International Nuclear Information System (INIS)

Deadrick, F.J.; Ramirez, A.L.; Lytle, R.J.

1981-01-01

The Lawrence Livermore National Laboratory is currently assessing the capabilities of high resolution geophysical methods to characterize geologic sites for the disposal of high level nuclear waste. A successful experiment has recently been performed in which salt water tracers and high frequency electromagnetic waves were utilized to map rock mass fracture zones in-situ. Multiple cross-borehole EM transmissions were used to generate a tomographic image of the fractured rock region between two boreholes. The tomographs obtained correlate well with conventional wireline geophysical logs which can be used to infer the location of fractured zones in the rock mass. This indirect data suggests that the geotomography and brine tracer technique may have merit in mapping fractured zones between boreholes

Definition of a critical confining zone using surface geophysical methods

International Nuclear Information System (INIS)

Eddy-Dilek, C.A.; Hoekstra, P.; Harthill, N.; Blohm, M.; Phillips, D.R.

1996-01-01

Definition of the hydrogeologic framework in layered sediments of fluvial and deltaic origin is a difficult challenge for environmental characterization and remediation programs due to the lithologic and stratigraphic heterogeneities inherent in these settings. These heterogeneties often control contaminant transport and the effectiveness of remediation alternatives, Surface geophysical surveys can be cost-effective methods for characterization, but individual methods have inherent limitations in resolution and sensitivity. A synergistic approach, utilizing two geophysical survey methods was applied, to define and examine the nature and extent of a deep confining zone of regulatory importance, the Crouch Branch Confining Unit, in Coastal Plain sediments at the Savannah River Site. TDEM accurately maps the overall conductance (product of thickness and electrical conductivity) of a confining zone clay facies; from variation in conductance, changes in lithology of the conforming zone can be inferred. Shear wave seismic reflection surveys map the depth to the clay layers, and the clay layer thickness, but provides little information on the lithologic nature of the confining zone. Integrated interpretation of the combined data set (including all available borehole logs) allows for delineation of the lateral and vertical extent of clay-dominated zones, sand-dominated zones, key stratigraphic horizons, and erosional features associated with unconformities. This approach has resulted in the collection of critical information that will be used to optimize remedial system design, representing a significant cost savings to environmental restoration programs at the Savannah River Site

The snake geothermal drilling project. Innovative approaches to geothermal exploration

Energy Technology Data Exchange (ETDEWEB)

Shervais, John W. [Utah State Univ., Logan, UT (United States); Evans, James P. [Utah State Univ., Logan, UT (United States); Liberty, Lee M. [Boise State Univ., ID (United States); Schmitt, Douglas R. [University of Alberta, Canada; Blackwell, David D. [Southern Methodist Univ., Dallas, TX (United States)

2014-02-21

The goal of our project was to test innovative technologies using existing and new data, and to ground-truth these technologies using slim-hole core technology. The slim-hole core allowed us to understand subsurface stratigraphy and alteration in detail, and to correlate lithologies observed in core with surface based geophysical studies. Compiled data included geologic maps, volcanic vent distribution, structural maps, existing well logs and temperature gradient logs, groundwater temperatures, and geophysical surveys (resistivity, magnetics, gravity). New data included high-resolution gravity and magnetic surveys, high-resolution seismic surveys, three slimhole test wells, borehole wireline logs, lithology logs, water chemistry, alteration mineralogy, fracture distribution, and new thermal gradient measurements.

Anomalous self potential (sp) log signatures observed in a water ...

African Journals Online (AJOL)

Geophysical logging was done after drilling had been completed in a water well at Okwudor, South Eastern Nigeria. Three electric logs were run viz: Self Potential (SP), Resistivity N16″ and N64″ logs. An anomaly was observed in the SP log. The SP results from this well show some deviation from the standard norm.

Subsea ice-bearing permafrost on the U.S. Beaufort Margin: 2. Borehole constraints

Science.gov (United States)

Ruppel, Carolyn D.; Herman, Bruce M.; Brothers, Laura L.; Hart, Patrick E.

2016-01-01

Borehole logging data from legacy wells directly constrain the contemporary distribution of subsea permafrost in the sedimentary section at discrete locations on the U.S. Beaufort Margin and complement recent regional analyses of exploration seismic data to delineate the permafrost's offshore extent. Most usable borehole data were acquired on a ∼500 km stretch of the margin and within 30 km of the contemporary coastline from north of Lake Teshekpuk to nearly the U.S.-Canada border. Relying primarily on deep resistivity logs that should be largely unaffected by drilling fluids and hole conditions, the analysis reveals the persistence of several hundred vertical meters of ice-bonded permafrost in nearshore wells near Prudhoe Bay and Foggy Island Bay, with less permafrost detected to the east and west. Permafrost is inferred beneath many barrier islands and in some nearshore and lagoonal (back-barrier) wells. The analysis of borehole logs confirms the offshore pattern of ice-bearing subsea permafrost distribution determined based on regional seismic analyses and reveals that ice content generally diminishes with distance from the coastline. Lacking better well distribution, it is not possible to determine the absolute seaward extent of ice-bearing permafrost, nor the distribution of permafrost beneath the present-day continental shelf at the end of the Pleistocene. However, the recovery of gas hydrate from an outer shelf well (Belcher) and previous delineation of a log signature possibly indicating gas hydrate in an inner shelf well (Hammerhead 2) imply that permafrost may once have extended across much of the shelf offshore Camden Bay.

Estimation of the non records logs from existing logs using artificial neural networks

Directory of Open Access Journals (Sweden)

Mehdi Mohammad Salehi

2017-12-01

Full Text Available Finding the information of the hydrocarbon reservoirs from well logs is one of the main objectives of the engineers. But, missing the log records (due to many reasons such as broken instruments, unsuitable borehole and etc. is a major challenge to achieve it. Prediction of the density and resistivity logs (Rt, DT and LLS from the conventional wire-line logs in one of the Iranian southwest oil fields is the main purpose of this study. Multilayer neural network was applied to develop an intelligent predictive model for prediction of the logs. A total of 3000 data sets from 3 wells (A, B and C of the studied field were used. Among them, the data of A, B and C wells were used to constructing and testing the model, respectively. To evaluate the performance of the model, the mean square error (MSE and correlation coefficient (R2 in the test data were calculated. A comparison between the MSE of the proposed model and recently intelligent models shows that the proposed model is more accurate than others. Acceptable accuracy and using conventional well logging data are the highlight advantages of the proposed intelligent model.

Formation factor logging in-situ by electrical methods. Background and methodology

International Nuclear Information System (INIS)

Loefgren, Martin; Neretnieks, Ivars

2002-10-01

Matrix diffusion has been identified as one of the most important mechanisms governing the retardation of radionuclides escaping from a deep geological repository for nuclear waste. Radionuclides dissolved in groundwater flowing in water-bearing fractures will diffuse into water filled micropores in the rock. Important parameters governing the matrix diffusion are the formation factor, the surface diffusion and sorption. This report focuses on the formation factor in undisturbed intrusive igneous rock and the possibility of measuring this parameter in-situ. The background to and the methodology of formation factor logging in-situ by electrical methods are given. The formation factor is here defined as a parameter only depending on the geometry of the porous system and not on the diffusing specie. Traditionally the formation factor has been measured by through diffusion experiments on core samples, which are costly and time consuming. It has been shown that the formation factor could also be measured by electrical methods that are faster and less expensive. Previously this has only been done quantitatively in the laboratory on a centimetre or decimetre scale. When measuring the formation factor in-situ in regions with saline groundwater only the rock resistivity and the pore water resistivity are needed. The rock resistivity could be obtained by a variety of geophysical downhole tools. Water-bearing fractures disturb the measurements and data possibly affected by free water has to be sorted out. This could be done without loosing too much data if the vertical resolution of the tool is high enough. It was found that the rock resistivity tool presently used by SKB are neither quantitative or have enough vertical resolution. Therefore the slimhole Dual-Laterolog from Antares was tested with good results. This tool has a high vertical resolution and gives quantitative rock resistivities that need no correction. At present there is no method of directly obtaining the

Formation factor logging in-situ by electrical methods. Background and methodology

Energy Technology Data Exchange (ETDEWEB)

Loefgren, Martin; Neretnieks, Ivars [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Chemical Engineering and Technology

2002-10-01

Matrix diffusion has been identified as one of the most important mechanisms governing the retardation of radionuclides escaping from a deep geological repository for nuclear waste. Radionuclides dissolved in groundwater flowing in water-bearing fractures will diffuse into water filled micropores in the rock. Important parameters governing the matrix diffusion are the formation factor, the surface diffusion and sorption. This report focuses on the formation factor in undisturbed intrusive igneous rock and the possibility of measuring this parameter in-situ. The background to and the methodology of formation factor logging in-situ by electrical methods are given. The formation factor is here defined as a parameter only depending on the geometry of the porous system and not on the diffusing specie. Traditionally the formation factor has been measured by through diffusion experiments on core samples, which are costly and time consuming. It has been shown that the formation factor could also be measured by electrical methods that are faster and less expensive. Previously this has only been done quantitatively in the laboratory on a centimetre or decimetre scale. When measuring the formation factor in-situ in regions with saline groundwater only the rock resistivity and the pore water resistivity are needed. The rock resistivity could be obtained by a variety of geophysical downhole tools. Water-bearing fractures disturb the measurements and data possibly affected by free water has to be sorted out. This could be done without loosing too much data if the vertical resolution of the tool is high enough. It was found that the rock resistivity tool presently used by SKB are neither quantitative or have enough vertical resolution. Therefore the slimhole Dual-Laterolog from Antares was tested with good results. This tool has a high vertical resolution and gives quantitative rock resistivities that need no correction. At present there is no method of directly obtaining the

Basalt stratigraphy - Pasco Basin

International Nuclear Information System (INIS)

Waters, A.C.; Myers, C.W.; Brown, D.J.; Ledgerwood, R.K.

1979-10-01

The geologic history of the Pasco Basin is sketched. Study of the stratigraphy of the area involved a number of techniques including major-element chemistry, paleomagnetic investigations, borehole logging, and other geophysical survey methods. Grande Ronde basalt accumulation in the Pasco Basin is described. An illustrative log response is shown. 1 figure

A positioning and data logging system for surface geophysical surveys

International Nuclear Information System (INIS)

Nyquist, J.E.; Blair, M.S.

1988-01-01

The Ultrasonic Ranging and Data System (USRADS) developed at ORNL is being adapted to work with two commercially available geophysical instruments: a magnetometer and an EM31 terrain conductivity meter. Geophysical surveys have proven an important preliminary step in investigating hazardous waste sites. Magnetometers and terrain conductivity meters are used to locate buried drums, trenches, conductive contaminant plumes and map regional changes in geology. About half the field time of a typical geophysical investigation is spent surveying the position of the grid points at which the measurements will be made. Additional time is lost and errors may be made recording instrument values in field notebooks and transcribing the data to a computer. Developed for gamma radiation surveys, the USRAD system keeps track of the surveyor's position automatically by triangulating on an ultrasonic transmitter carried in a backpack. The backpack also contains a radio transmitter that sends the instrument's reading coincident with the ultrasonic pulse. The surveyor's position and the instrument's reading are recorded by a portable computer which can plot the data to check the survey's progress. Electronic files are stored in a form compatible with AutoCAD to speed report writing. 7 refs., 3 figs

Geophysical mapping of complex glaciogenic large-scale structures

DEFF Research Database (Denmark)

Høyer, Anne-Sophie

2013-01-01

This thesis presents the main results of a four year PhD study concerning the use of geophysical data in geological mapping. The study is related to the Geocenter project, “KOMPLEKS”, which focuses on the mapping of complex, large-scale geological structures. The study area is approximately 100 km2...... data types and co-interpret them in order to improve our geological understanding. However, in order to perform this successfully, methodological considerations are necessary. For instance, a structure indicated by a reflection in the seismic data is not always apparent in the resistivity data...... information) can be collected. The geophysical data are used together with geological analyses from boreholes and pits to interpret the geological history of the hill-island. The geophysical data reveal that the glaciotectonic structures truncate at the surface. The directions of the structures were mapped...

Utilisation of prompt fission neutron technology in Greenfields uranium exploration

International Nuclear Information System (INIS)

Mutz, P.R.

2007-01-01

Conventionally, gamma detection technology has been used in uranium exploration programs for the initial detection of uranium as well as for a determination of uranium concentration. Geophysical logging companies use wireline gamma probes to measure uranium within boreholes, and field technicians utilise hand held gamma meters to detect uranium in rock samples, drill cuttings and cores. Borehole geophysical logging equipment typically records the uranium concentration as %eU 3 O8, where e represents an equivalent determination of uranium concentration as opposed to a laboratory assay. This method of uranium determination is an indirect method, as it measures gamma radiation from uranium-238 (U-238) isotope decay chain progeny; principally the bismuth-214 (Bi-214) isotope. Consequently, the uranium determination can be inaccurate due to natural disequilibrium between the U-238 parent and the decay chain progeny. This is especially true in sedimentary hosted uranium deposits, where the uranium and daughter progeny may have been geochemically separated. The gamma detection method for uranium can also be rendered inaccurate by detecting the gamma signature from potassium in clays as well as from thorium; both of which can provide a false (enhanced) eU 3 O8 determination. Prompt Fission Neutron (PFN) technology is a geophysical wireline logging technology used in the same manner as conventional gamma logging. The difference is that PFN provides a direct determination of uranium within a borehole, irrespective of natural disequilibrium or the presence of other radioactive elements. This paper provides a brief description of natural uranium and radioactivity as a basis for explaining the conventional use of gamma radiation detectors for the detection and determination of uranium concentration in exploration boreholes, including the potential pitfalls of this technology. A detailed description of prompt fission neutron technology is also presented, along with a discussion

Scientific results from the deepened Lopra-1 borehole, Faroe Islands: Thermal structure of the deep Lopra-1/1A borehole in the Faroe Islands

Directory of Open Access Journals (Sweden)

Breiner, Niels

2006-07-01

Full Text Available nformation on temperature, temperature gradients, thermal conductivity and heat flow from the c. 3.5 km deep Lopra-1/1A borehole in the Faroe Islands is presented and analysed. The upper 2450 m of the drilled sequence consists of thick tholeiitic basalt flows and the deeper parts of hyaloclastites and thin beds of basalt. Temperature data originate from high precision temperature logging a long time after drilling to a depth of 2175 m (the original Lopra-1 borehole and from commercial temperature logs measured a short time after drilling to a depth of 3430 m (Lopra-1/1A. The high-precision temperature log determines accurately levels of inflow of groundwater to the borehole and significantthermal disturbances to a depth of c. 1250 m. Below 1300 m, no significant disturbances are seen and interval temperature gradients for large depth intervals show only small variations between 28 and 33°C/km. The mean least-squares gradient for the depth interval of 1400–3430 m is 31.4°C/ km. In clear contrast to these overall very homogeneous, large-interval, mean temperature gradients, great local variability, between gradients of 20–25°C/km and 45°C/km, was observed between about 1300 and 2175 m (maximum depth of the high-resolution temperature log. These gradient variations are interpreted to be due to thermal conductivity variations and to reflect varying secondary mineralisation and mineral alterations.A preliminary analysis of the Lopra-1/1A temperature–depth function in terms of long-term palaeoclimatic signals indicates subsurface temperatures below about 1300 m to be in equilibrium with mean surface temperatures significantly below zero during the last glacial period. A subsequent temperature increase of 12–16°C occurred at around the termination of the last glaciation. The measured temperatures (some after correction and the thermal regime below 1300 m seem to represent conductive equilibrium conditions without significant disturbances

Borehole data package for well 299-W15-41 at single-shell tank waste management Area TX-TY

International Nuclear Information System (INIS)

Horton, D.G.; Hodges, F.N.

2000-01-01

One new Resource Conservation and Recovery Act (RCRA) groundwater monitoring well was installed at the single-shell tank farm Waste Management Area (WMA) TX-TY during December 1999 and January 2000 in fulfillment of Tri-Party Agreement (Ecology 1996) milestone M-24-43. The well is 299-W15-41 and is located south of the 241-TX tank farm and south of 20th Street in the 200 West Area. A figure shows the locations of all wells in the WMA TX-TY monitoring network. The new well was constructed to the specifications and requirements described in Washington Administrative Code (WAC) 173-160 and WAC 173-303, the groundwater monitoring plan for WMA TX-TY (Caggiano and Goodwin 1991), the assessment plan for WMA TX-TY (Caggiano and Chou 1993), and the description of work for well drilling and installation. This document compiles information on the drilling and construction, well development, pump installation, and sediment testing applicable to well 299-W1 5-41. Appendix A contains the geologist's log, the Well Construction Summary Report, and Well Summary Sheet (as-built diagram) and Appendix B contains borehole geophysical logs. Additional documentation concerning well construction is on file with Bechtel Hanford, Inc., Richland, Washington

California-Nevada uranium logging. Final report

International Nuclear Information System (INIS)

1981-04-01

The purpose of this project was to obtain geophysical logs of industry drill holes to assess the uranium resource potential of geologic formations of interest. The work was part of the US Department of Energy's National Uranium Resource Evaluation (NURE) Program. The principal objective of the logging program was to determine radioelement grade of formations through natural gamma ray detectors. Supplementary information was obtained from resistivity (R), self-potential (SP), point resistance (RE), and neutron density (NN) logs for formation interpretation. Additional data for log interpretation was obtained from caliper logs, casing schedules, and downhole temperature. This data was obtained from well operators when available, with new logs obtained where not formerly available. This report contains a summary of the project and data obtained to date

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

International Nuclear Information System (INIS)

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

Investigating lithological and geophysical relationships with applications to geological uncertainty analysis using Multiple-Point Statistical methods

DEFF Research Database (Denmark)

Barfod, Adrian

The PhD thesis presents a new method for analyzing the relationship between resistivity and lithology, as well as a method for quantifying the hydrostratigraphic modeling uncertainty related to Multiple-Point Statistical (MPS) methods. Three-dimensional (3D) geological models are im...... is to improve analysis and research of the resistivity-lithology relationship and ensemble geological/hydrostratigraphic modeling. The groundwater mapping campaign in Denmark, beginning in the 1990’s, has resulted in the collection of large amounts of borehole and geophysical data. The data has been compiled...... in two publicly available databases, the JUPITER and GERDA databases, which contain borehole and geophysical data, respectively. The large amounts of available data provided a unique opportunity for studying the resistivity-lithology relationship. The method for analyzing the resistivity...

High-resolution, short-range, in-mine geophysical techniques for the delineation of South African orebodies

CSIR Research Space (South Africa)

Van Schoor, Abraham M

2006-02-28

Full Text Available ) • Geophysical techniques Ground penetrating radar (GPR) Borehole radar Electrical resistance tomography (ERT) • Case studies Waterval Mine (GPR) Mponeng Gold Mine (Borehole Radar) Western Platinum Mine (ERT) • Conclusion • Future research... equivalent – e.g. electrical resistance tomography (ERT) is based on medical impedance tomography Gold and platinum mining in South Africa An overview Slide 9 © CSIR 2006 www.csir.co.za Gold and platinum mining in South Africa...

Laboratory ultrasonic pulse velocity logging for determination of elastic properties from rock core

Science.gov (United States)

Blacklock, Natalie Erin

During the development of deep underground excavations spalling and rockbursting have been recognized as significant mechanisms of violent brittle failure. In order to predict whether violent brittle failure will occur, it is important to identify the location of stiffness transitions that are associated with geologic structure. One approach to identify the effect of geologic structures is to apply borehole geophysical tools ahead of the tunnel advance. Stiffness transitions can be identified using mechanical property analysis surveys that combine acoustic velocity and density data to calculate acoustic estimates of elastic moduli. However, logistical concerns arise since the approach must be conducted at the advancing tunnel face. As a result, borehole mechanical property analyses are rarely used. Within this context, laboratory ultrasonic pulse velocity testing has been proposed as a potential alternative to borehole mechanical property analysis since moving the analysis to the laboratory would remove logistical constraints and improve safety for the evaluators. In addition to the traditional method of conducting velocity testing along the core axis, two new methodologies for point-focused testing were developed across the core diameter, and indirectly along intact lengths of drill core. The indirect test procedure was implemented in a continuous ultrasonic velocity test program along 573m of drill core to identify key geologic structures that generated transitions in ultrasonic elastic moduli. The test program was successful at identifying the location of geologic contacts, igneous intrusions, faults and shear structures. Ultrasonic values of Young's modulus and bulk modulus were determined at locations of significant velocity transitions to examine the potential for energy storage and energy release. Comparison of results from different ultrasonic velocity test configurations determined that the indirect test configuration provided underestimates for values of

Determination of Groundwater Velocity and Dispersion Parameters by Borehole Wall Multielectrode Geoelectrics

Science.gov (United States)

Kessels, W.; Wuttke, M. W.

2007-05-01

A single well technique to determine groundwater flow values and transport parameters is presented. Multielectrode arrays are placed at the filtered casing depth by an inflatable packer or are installed on the borehole wall behind the casing.Tracer water with a higher or lower specific electrical conductivity (salinity) which is injected between the electrodes. This tracer plume then moves into the natural groundwater flow field. The observation of this movement by geoelectric logging enables the determination of the groundwater velocity and salinity. The transport parameters "effective porosity" and "dispersion length" can also be derived. The geoelectric logging uses n borehole electrodes and two grounding electrodes. Thus, either n independent two point measurements or n*(n-1)/2 pole-to-pole measurements can be conducted to obtain a full set of geoelectric measurements. This set is used to derive all electrode combinations by applying the law of superposition and reciprocity. The tracer distribution around the borehole during and after injection depends on the hydraulic and transport parameters of the aquifer and the filter sand. The transport parameter "porosity" plus the total injected tracer volume determines the tracer distribution around the borehole. The transport parameter "dispersivity" determines the abruptness of the tracer front. The method was tested by undertaking measurements in a lab aquifer filled with sand. The results are discussed and the limitations of the method are shown. Multielectrode installations behind casing were tested in situ in the two scientific boreholes CAT-LUD-1 and CAT- LUD-1A drilled in the northern part of Germany. A multielectrode packer system was designed, built and tested in these boreholes. The results are compared with colloid observations in the borehole and hydraulic triangulation in surrounded observation wells. Here, the interpretation of these in situ measurements is mainly restricted to two point geoelectric

Calibration of a neutron log in partially saturated media. Part II. Error analysis

International Nuclear Information System (INIS)

Hearst, J.R.; Kasameyer, P.W.; Dreiling, L.A.

1981-01-01

Four sources or error (uncertainty) are studied in water content obtained from neutron logs calibrated in partially saturated media for holes up to 3 m. For this calibration a special facility was built and an algorithm for a commercial epithermal neutron log was developed that obtains water content from count rate, bulk density, and gap between the neutron sonde and the borehole wall. The algorithm contained errors due to the calibration and lack of fit, while the field measurements included uncertainties in the count rate (caused by statistics and a short time constant), gap, and density. There can be inhomogeneity in the material surrounding the borehole. Under normal field conditions the hole-size-corrected water content obtained from such neutron logs can have an uncertainty as large as 15% of its value

Flow and sorption controls of groundwater arsenic in individual boreholes from bedrock aquifers in central Maine, USA.

Science.gov (United States)

Yang, Qiang; Culbertson, Charles W; Nielsen, Martha G; Schalk, Charles W; Johnson, Carole D; Marvinney, Robert G; Stute, Martin; Zheng, Yan

2015-02-01

To understand the hydrogeochemical processes regulating well water arsenic (As) evolution in fractured bedrock aquifers, three domestic wells with [As] up to 478 μg/L are investigated in central Maine. Geophysical logging reveals that fractures near the borehole bottom contribute 70-100% of flow. Borehole and fracture water samples from various depths show significant proportions of As (up to 69%) and Fe (93-99%) in particulates (>0.45 μm). These particulates and those settled after a 16-day batch experiment contain 560-13,000 mg/kg of As and 14-35% weight/weight of Fe. As/Fe ratios (2.5-20 mmol/mol) and As partitioning ratios (adsorbed/dissolved [As], 20,000-100,000 L/kg) suggest that As is sorbed onto amorphous hydrous ferric oxides. Newly drilled cores also show enrichment of As (up to 1300 mg/kg) sorbed onto secondary iron minerals on the fracture surfaces. Pumping at high flow rates induces large decreases in particulate As and Fe, a moderate increase in dissolved [As] and As(III)/As ratio, while little change in major ion chemistry. The δD and δ(18)O are similar for the borehole and fracture waters, suggesting a same source of recharge from atmospheric precipitation. Results support a conceptual model invoking flow and sorption controls on groundwater [As] in fractured bedrock aquifers whereby oxygen infiltration promotes the oxidation of As-bearing sulfides at shallower depths in the oxic portion of the flow path releasing As and Fe; followed by Fe oxidation to form Fe oxyhydroxide particulates, which are transported in fractures and sorb As along the flow path until intercepted by boreholes. In the anoxic portions of the flow path, reductive dissolution of As-sorbed iron particulates could re-mobilize As. For exposure assessment, we recommend sampling of groundwater without filtration to obtain total As concentration in groundwater. Copyright © 2014 Elsevier B.V. All rights reserved.

Mud Gas Logging In A Deep Borehole: IODP Site C0002, Nankai Trough Accretionary Prism

Science.gov (United States)

Toczko, S.; Hammerschmidt, S.; Maeda, L.