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Three-axis accelerometer package for slimhole and microhole seismic monitoring and surveys

Description: The development of microdrilling technology, nominally defined as drilling technology for 1-in.-diameter boreholes, shows potential for reducing the cost of drilling monitoring wells. A major question that arises in drilling microholes is if downhole logging and monitoring in general--and downhole seismic surveying in particular--can be conducted in such small holes since the inner working diameter of such a seismic tool could be as small as 0.31 in. A downhole three-component accelerometer package that fits within a 031-in. inner diameter tube has been designed, built, and tested. The package consists of three orthogonally mounted Entran EGA-125-5g piezoresistive silicon micromachined accelerometers with temperature compensation circuitry, downhole amplification, and line drivers mounted in a thin-walled aluminum tube. Accelerometers are commercially available in much smaller package sizes than conventional geophones, but the noise floor is significantly higher than that for the geophones. Cross-well tests using small explosives showed good signal-to-noise ratio in the recorded waveform at various receiver depths with a 1,50-ft source-receiver well separation. For some active downhole surveys, the accelerometer unit would clearly be adequate. It can be reasonably assumed, however, that for less energetic sources and for greater well separations, the high accelerometer noise floor is not acceptable. By expanding the inner working diameter of a microhole seismic tool to 0.5 in., other commercial accelerometers can be used with substantially lower noise floors.
Date: January 7, 1997
Creator: Hunter, S.L. & Harben, P.E.
Partner: UNT Libraries Government Documents Department

Real-time earthquake alert system for the greater San Francisco Bay Area: a prototype design to address operational issues

Description: The purpose of the earthquake alert system (EAS) is to outrun the seismic energy released in a large earthquake using a geographically distributed network of strong motion sensors that telemeter data to a rapid CPU-processing station, which then issues an area-wide warning to a region before strong motion will occur. The warning times involved are short, from 0 to 30 seconds or so; consequently, most responses must be automated. The San Francisco Bay Area is particularly well suited for an EAS because (1) large earthquakes have relatively shallow hypocenters (10- to 20-kilometer depth), giving favorable ray-path geometries for larger warning times than deeper from earthquakes, and (2) the active faults are few in number and well characterized, which means far fewer geographically distributed strong motion sensors are (about 50 in this region). An EAS prototype is being implemented in the San Francisco Bay Area. The system consists of four distinct subsystems: (1) a distributed strong motion seismic network, (2) a central processing station, (3) a warning communications system and (4) user receiver and response systems. We have designed a simple, reliable, and inexpensive strong motion monitoring station that consists of a three-component Analog Devices ADXLO5 accelerometer sensing unit, a vertical component weak motion sensor for system testing, a 16-bit digitizer with multiplexing, and communication output ports for RS232 modem or radio telemetry. The unit is battery-powered and will be sited in fire stations. The prototype central computer analysis system consists of a PC dam-acquisition platform that pipes the incoming strong motion data via Ethernet to Unix-based workstations for dam processing. Simple real-time algorithms, particularly for magnitude estimation, are implemented to give estimates of the time since the earthquake`s onset its hypocenter location, its magnitude, and the reliability of the estimate. These parameters are calculated and transmitted with frequent updates as ...
Date: December 10, 1996
Creator: Harben, P.E.; Jarpe, S. & Hunter, S.
Partner: UNT Libraries Government Documents Department

Borehole seismic monitoring of seismic stimulation at OccidentalPermian Ltd's -- South Wason Clear Fork Unit

Description: Seismic stimulation is a proposed enhanced oil recovery(EOR) technique which uses seismic energy to increase oil production. Aspart of an integrated research effort (theory, lab and field studies),LBNL has been measuring the seismic amplitude of various stimulationsources in various oil fields (Majer, et al., 2006, Roberts,et al.,2001, Daley et al., 1999). The amplitude of the seismic waves generatedby a stimulation source is an important parameter for increased oilmobility in both theoretical models and laboratory core studies. Theseismic amplitude, typically in units of seismic strain, can be measuredin-situ by use of a borehole seismometer (geophone). Measuring thedistribution of amplitudes within a reservoir could allow improved designof stimulation source deployment. In March, 2007, we provided in-fieldmonitoring of two stimulation sources operating in Occidental (Oxy)Permian Ltd's South Wasson Clear Fork (SWCU) unit, located near DenverCity, Tx. The stimulation source is a downhole fluid pulsation devicedeveloped by Applied Seismic Research Corp. (ASR). Our monitoring used aborehole wall-locking 3-component geophone operating in two nearbywells.
Date: April 30, 2007
Creator: Daley, Tom & Majer, Ernie
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume I P-Wave Measurements in Borehole C4993 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.

Description: In this volume (I), all P-wave measurements are presented that were performed in Borehole C4993 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 370 to 1400 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1200 ft, depth intervals of 20 ft were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4993, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4993, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.
Date: July 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume II P-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.

Description: In this volume (II), all P-wave measurements are presented that were performed in Borehole C4996 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 360 to 1400 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1180 ft, depth intervals of 20 ft were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4996, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4996, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.
Date: July 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume III P-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted P-Wave Velocity Profile.

Description: In this volume (III), all P-wave measurements are presented that were performed in Borehole C4997 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. P-wave measurements were performed over the depth range of 390 to 1220 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used. Compression (P) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 40 ft (later relocated to 27.5 ft due to visibility in borehole after rain) in Borehole C4997, and a 3-D geophone from the University of Texas was embedded near the borehole at about 1.5 ft below the ground surface. This volume is organized into 12 sections as follows: Section 1: Introduction, Section 2: Explanation of Terminology, Section 3: Vp Profile at Borehole C4997, Sections 4 to 6: Unfiltered P-wave records of lower vertical receiver, reaction mass, and reference receiver, Sections 7 to 9: Filtered P-wave signals of lower vertical receiver, reaction mass and reference receiver, Section 10: Expanded and filtered P-wave signals of lower vertical receiver, and Sections 11 and 12: Waterfall plots of unfiltered and filtered lower vertical receiver signals.
Date: June 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume IV S-Wave Measurements in Borehole C4993 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.

Description: In this volume (IV), all S-wave measurements are presented that were performed in Borehole C4993 at the Waste Treatment Plant (WTP) with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver. S-wave measurements were performed over the depth range of 370 to 1300 ft, typically in 10-ft intervals. However, in some interbeds, 5-ft depth intervals were used, while below about 1200 ft, depth intervals of 20 ft were used. Shear (S) waves were generated by moving the base plate of T-Rex for a given number of cycles at a fixed frequency as discussed in Section 2. This process was repeated so that signal averaging in the time domain was performed using 3 to about 15 averages, with 5 averages typically used. In addition, a second average shear wave record was recorded by reversing the polarity of the motion of the T-Rex base plate. In this sense, all the signals recorded in the field were averaged signals. In all cases, the base plate was moving perpendicular to a radial line between the base plate and the borehole which is in and out of the plane of the figure shown in Figure 1.1. The definition of “in-line”, “cross-line”, “forward”, and “reversed” directions in items 2 and 3 of Section 2 was based on the moving direction of the base plate. In addition to the LBNL 3-D geophone, called the lower receiver herein, a 3-D geophone from Redpath Geophysics was fixed at a depth of 22 ft in Borehole C4993, and a 3-D geophone from the University of Texas (UT) was embedded near the borehole at about 1.5 ft below the ground surface. The Redpath geophone and the UT geophone were properly aligned so that one of the horizontal components in each ...
Date: June 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume V S-Wave Measurements in Borehole C4996 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.

Description: Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (V), all S-wave measurements are presented that were performed in Borehole C4996 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.
Date: June 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Deep Downhole Seismic Testing at the Waste Treatment Plant Site, Hanford, WA. Volume VI S-Wave Measurements in Borehole C4997 Seismic Records, Wave-Arrival Identifications and Interpreted S-Wave Velocity Profile.

Description: Velocity measurements in shallow sediments from ground surface to approximately 370 to 400 feet bgs were collected by Redpath Geophysics using impulsive S- and P-wave seismic sources (Redpath 2007). Measurements below this depth within basalt and sedimentary interbeds were made by UTA between October and December 2006 using the T-Rex vibratory seismic source in each of the three boreholes. Results of these measurements including seismic records, wave-arrival identifications and interpreted velocity profiles are presented in the following six volumes: I. P-Wave Measurements in Borehole C4993 II. P-Wave Measurements in Borehole C4996 III. P-Wave Measurements in Borehole C4997 IV. S-Wave Measurements in Borehole C4993 V. S-Wave Measurements in Borehole C4996 VI. S-Wave Measurements in Borehole C4997 In this volume (VI), all S-wave measurements are presented that were performed in Borehole C4997 at the WTP with T-Rex as the seismic source and the Lawrence Berkeley National Laboratory (LBNL) 3-D wireline geophone as the at-depth borehole receiver.
Date: June 6, 2007
Creator: Stokoe, Kenneth H.; Li, Song Cheng; Cox, Brady R. & Menq, Farn-Yuh
Partner: UNT Libraries Government Documents Department

Elastic modeling and steep dips: unraveling the reflected wavefield

Description: As part of a larger elastic numerical modeling project, we have been investigating how energy reflected from steeply dipping interfaces is recorded using typical multicomponent acquisition geometries. Specifically, we have been interpreting how rcflection events from the flanks of salt dome structures are distributed on 3C and 4C phones for vertical seismic profiles (VSPs) and ocean bottom seismic (OBS) or land surface surveys. The ultimate goal of this investigation is to improve the structural imaging of steeply dipping interfaces and eventually to evaluate the usc of the recorded elastic wavefield for fluid description near these interfaces. In the current work, we focus on a common assumption used when processing converted wave reflection seismic data that most PP energy is recorded on the vertical geophone and/or the hydrophone and that most PS energy is recorded on the horizontal geophones. This is a useful assumption when it is valid, because it eliminates the need for separation of the recorded wavefield into P and S wavetypes. Using two elastic models and different acquisition geometries, we examine the validity of this assumption in the presence of steeply dipping interfaces and discuss the implications for converted-wave and vector imaging of salt flanks.
Date: January 1, 2003
Creator: Hoelting, C. J. (Cory J.); Gherasim, M. (Mariana); House, L. S. (Leigh S.) & Marfurt, K. J.
Partner: UNT Libraries Government Documents Department

VIBRATION MEASUREMENTS IN A RHIC QUADRUPOLE AT CRYOGENIC TEMPERATURES.

Description: One of the concerns in using compact superconducting magnets in the final focus region of the ILC is the influence of the cryogen flow on the vibration characteristics. As a first step towards characterizing such motion at nanometer levels, a project was undertaken at BNL to measure the vibrations in a spare RHIC quadrupole under cryogenic conditions. Given the constraints of cryogenic operation, and limited space available, it was decided to use a dual head laser Doppler vibrometer for this work. The performance of the laser vibrometer was tested in a series of room temperature tests and compared with results from Mark L4 geophones. The laser system was then used to measure the vibration of the cold mass of the quadrupole with respect to the outside warm enclosure. These measurements were carried out both with and without the flow of cold helium through the magnet. The results indicate only a minor increase in motion in the horizontal direction (where the cold mass is relatively free to move).
Date: October 17, 2005
Creator: JAIN, A.; AYDIN, S.; HE, P.; ANERELLA, M.; GANETIS, G.; HARRISON, M. et al.
Partner: UNT Libraries Government Documents Department

Borehole Seismic Monitoring at Otway Using the Naylor-1 Instrument String

Description: The Naylor-1 monitoring completion, a unique and innovative instrumentation package, was designed and fabricated in FY 2007 at Berkeley Laboratory. Tom Daley, Barry Freifeld and Duo Wang (all from Berkeley Lab) were on site at the Otway Project between September 26 and October 14, 2007, working with CO2CRC and their subcontractors, AGR Asia Pacific and Eastern Well Services to complete Naylor-1 and initiate baseline data collection. Figure 1 shows a schematic of Naylor-1's sensor layout. There are three U-tube geochemical samplers, with one located near the top of the residual CH{sub 4} gas cap and two located beneath the gas-water contact. The 21 geophones are used for performing three distinct seismic measurements, high resolution travel time (HRTT), walkaway vertical seismic profiling (WVSP), and microseismic monitoring. These activities are separated in to active source seismic and microseismic monitoring, and will be described separately.
Date: June 1, 2009
Creator: Daley, T.M.; Sharma, Sandeep; Dzunic, Aleksander; Urosevic, Milovan; Kepic, Anton & Sherlock, Don
Partner: UNT Libraries Government Documents Department

Acquisition of time-lapse, 6-component, P- and S-wave, crosswell seismic survey with orbital vibrator and of time-lapse VSP for CO2 injection monitoring

Description: Using an orbital vibrator source (2-components), and a 40 level 3-component geophone string, a 6-component crosswell survey was acquired before and after a CO2 injection in a saline aquifer. Decomposition of the two source components and component rotation of both source and sensors created good separation of P- and S-wave energy allowing independent analysis of travel time and reflectivity. A time-lapse VSP was also acquired.
Date: July 15, 2004
Creator: Daley, Tom; Daley, T. M.; Myer, L.R. & Majer, E.L.
Partner: UNT Libraries Government Documents Department

Acoustic and Seismic Modalities for Unattended Ground Sensors

Description: In this paper, we have presented the relative advantages and complementary aspects of acoustic and seismic ground sensors. A detailed description of both acoustic and seismic ground sensing methods has been provided. Acoustic and seismic phenomenology including source mechanisms, propagation paths, attenuation, and sensing have been discussed in detail. The effects of seismo-acoustic and acousto-seismic interactions as well as recommendations for minimizing seismic/acoustic cross talk have been highlighted. We have shown representative acoustic and seismic ground sensor data to illustrate the advantages and complementary aspects of the two modalities. The data illustrate that seismic transducers often respond to acoustic excitation through acousto-seismic coupling. Based on these results, we discussed the implications of this phenomenology on the detection, identification, and localization objectives of unattended ground sensors. We have concluded with a methodology for selecting the preferred modality (acoustic and/or seismic) for a particular application.
Date: March 31, 1999
Creator: Elbring, G.J.; Ladd, M.D.; McDonald, T.S. & Sleefe, G.E.
Partner: UNT Libraries Government Documents Department

Downhole Seismic Monitoring at the Geysers

Description: A 500-ft length, 6-level, 3-component, vertical geophone array was permanently deployed within the upper 800 ft of Unocal's well GDCF 63-29 during a plug and abandonment operation on April 7, 1998. The downhole array remains operational after a period of 1 year, at a temperature of about 150 C. Continuous monitoring and analysis of shallow seismicity (<4000 ft deep) has been conducted over that same 1-year period. The downhole array was supplemented with 4 surface stations in late-1998 and early-1999 to help constrain locations of shallow seismicity. Locations occurring within about 1 km ({approximately}3000 ft) of the array have been determined for a subset of high-frequency events detected on the downhole and surface stations for the 10-week period January 6 to March 16, 1999. These events are distinct from surface-monitored seismicity at The Geysers in that they occur predominantly above the producing reservoir, at depths ranging from about 1200 to 4000 ft depth (1450 to -1350 ft elevation). The shallow seismicity shows a northeast striking trend, similar to seismicity trends mapped deeper within the reservoir and the strike of the predominant surface lineament observed over the productive field.
Date: October 17, 1999
Creator: Rutledge, J.T.; Anderson, T.D.; Fairbanks, T.D. & Albright, J.N.
Partner: UNT Libraries Government Documents Department

Advanced array techniques for unattended ground sensor applications

Description: Sensor arrays offer opportunities to beam form, and time-frequency analyses offer additional insights to the wavefield data. Data collected while monitoring three different sources with unattended ground sensors in a 16-element, small-aperture (approximately 5 meters) geophone array are used as examples of model-based seismic signal processing on actual geophone array data. The three sources monitored were: (Source 01). A frequency-modulated chirp of an electromechanical shaker mounted on the floor of an underground bunker. Three 60-second time-windows corresponding to (a) 50 Hz to 55 Hz sweep, (b) 60 Hz to 70 Hz sweep, and (c) 80 Hz to 90 Hz sweep. (Source 02). A single transient impact of a hammer striking the floor of the bunker. Twenty seconds of data (with the transient event approximately mid-point in the time window.(Source 11)). The transient event of a diesel generator turning on, including a few seconds before the turn-on time and a few seconds after the generator reaches steady-state conditions. The high-frequency seismic array was positioned at the surface of the ground at a distance of 150 meters (North) of the underground bunker. Four Y-shaped subarrays (each with 2-meter apertures) in a Y-shaped pattern (with a 6-meter aperture) using a total of 16 3-component, high-frequency geophones were deployed. These 48 channels of seismic data were recorded at 6000 and 12000 samples per second on 16-bit data loggers. Representative examples of the data and analyses illustrate the results of this experiment.
Date: May 6, 1997
Creator: Followill, F.E.; Wolford, J.K. & Candy, J.V.
Partner: UNT Libraries Government Documents Department

Event location in the Middle East and North Africa

Description: The Lawrence Livermore National Laboratory (LLNL) CTBT R{ampersand}D program has made significant progress towards improving the ability of the IMS seismic network to locate small-magnitude events in the Middle East and North Africa (MIYNA). Given that high-grade ground truth (such as known explosions) has been difficult to obtain in these regions, we have placed a significant effort towards the development of a teleseismically constrained seismic database that provides event locations good to within 20m km. This data set is used to make an initial evaluation of the effectiveness of calibration on the proposed seismic IMS network in the MWNA. Utilizing a surrogate IMS regional network in the Middle East we find that when a seismic event lies within the footprint of the recording network the uncalibrated event locations are good to within about 25 km of the teleseismically constrained (TC) location. Using region-specific static station corrections further reduces this difference to about 20 km. To obtain further improvement in location accuracy we have used the modified kriging technique developed by SNL to interpolate new travel-time corrections. We compare this technique withe other robust linear interpolation techniques with the goal of enhancing the estimation of travel-time corrections. This is important to TC events which we find can have large uncorrelated uncertainties. Finally, we are making a large effort to incorporate LLNL analyst picks on primary and secondary phases and develop azimuth and slownsess estimates horn current IMS arrays to improve/supplement the NEIC picks.
Date: July 1, 1997
Creator: Schultz, C. A.; Myers, S. C. & Ruppert, S. D.
Partner: UNT Libraries Government Documents Department

Seismic Response of a Deep Underground Geologic Repository for Nuclear Waste at the Waste Isolation Pilot Plant in New Mexico

Description: The Waste Isolation Pilot Plant (WIPP) is a deep underground nuclear waste repository certified by the U.S. Environmental Protection Agency ,(EPA) to store transuranic defense-related waste contaminated by small amounts of radioactive materials. Located at a depth of about 655 meters below the surface, the facility is sited in southeastern New Mexico, about 40 Department of Energy underground facilities, waste disposal. kilometers east of the city of Carlsbad, New Mexico. The U.S. (DOE) managed the design and construction of the surface and and remains responsible for operation and closure following The managing and operating contractor for the DOE at the WIPP, Westinghouse Electric Corporation, maintains two rechmiant seismic monitoring systems located at the surface and in the underground. This report discusses two earthquakes detected by the seismic monitoring system, one a duratior magnitude 5.0 (Md) event located approximately 60 km east-southeast of the facility, and another a body-wave magnitude 5.6 (rob) event that occurred approximately 260 kilometers to the south-southeast.
Date: November 2, 1998
Creator: Sanchez, P.E.
Partner: UNT Libraries Government Documents Department

EXPLORING FOR SUBTLE MISSION CANYON STRATIGRAPHIC TRAPS WITH ELASTIC WAVEFIELD SEISMIC TECHNOLOGY

Description: A source-receiver geometry was designed for a 9C3D seismic survey in Montrail County, North Dakota, that will involve the largest number of active 3-component stations (1,800 to 2,100) ever attempted in an onshore U.S. multicomponent seismic survey. To achieve the data-acquisition objectives, 3-component geophone strings will be provided by the Bureau of Economic Geology, Dawson Geophysical, and Vecta Technology. Data acquisition will commence in late October 2003. The general objective of this study is to demonstrate the value of multicomponent seismic technology for exploring for subtle oolitic-bank reservoirs in the Mission Canyon Formation of the Williston Basin. The work tasks done during this report period concentrated on developing an optimal design for the seismic survey. This first semiannual report defines the geographical location and geometrical shape of the survey and documents the key acquisition parameters that will be implemented to yield high-fold, high-resolution 9-component seismic data.
Date: October 1, 2003
Creator: Beecherl, John
Partner: UNT Libraries Government Documents Department

24-CHANNEL GEOPHONE ARRAY FOR HORIZONTAL OR VERTICAL BOREHOLES

Description: This report describes the technical progress on a project to design and construct a multichannel geophone array that improves tomographic imaging capabilities in both surface and underground mines. Especially important in the design of the array is sensor placement. One issue related to sensor placement is addressed in this report: the method for clamping the sensor once it is emplaced in the borehole. If the sensors (geophones) are not adequately coupled to the surrounding rock mass, the resulting data will be of very poor quality. Improved imaging capabilities will produce energy, environmental, and economic benefits by increasing exploration accuracy and reducing operating costs.
Date: January 1, 2003
Creator: Westman, Erik C.
Partner: UNT Libraries Government Documents Department

AUTOMATING SHALLOW SEISMIC IMAGING

Description: Our current EMSP project continues an effort begun in 1997 to develop ultrashallow seismic imaging as a cost-effective method applicable to DOE facilities. The objective of the present research is to refine and demonstrate the use of an automated method of conducting shallow seismic surveys--an approach that represents a significant departure from conventional seismic-survey field procedures. Recent tests involving a second-generation mechanical geophone-planting device have shown that large numbers of geophones can be placed quickly and automatically and can acquire good data. In some easy-access environments, this device is expected to make shallow seismic surveying considerably more efficient and less expensive. Another element of our research plan involves monitoring the cone of depression of a pumping well that serves as a proxy location for fluid-flow at a contaminated site. In May 2001, we collected data from a well site at which drawdown equilibrium had been reached. That information is being interpreted and evaluated. The development of noninvasive, in-situ methods such as placing geophones automatically and using near-surface seismic methods alone or in concert with ground-penetrating radar to identify and characterize the hydrologic flow regimes at contaminated sites supports the prospect of developing effective, cost-conscious cleanup strategies for DOE and others.
Date: June 1, 2002
Creator: Steeples, Don W.
Partner: UNT Libraries Government Documents Department

Modified Noise Power Ratio testing of high resolution digitizers

Description: A broadband, full signal range, side-by-side (tandem) test method for estimating the internal noise performance of high resolution digitizers is described and illustrated. The technique involves a re-definition of the traditional Noise Power Ratio (NPR) test, a change that not only makes this test applicable to higher resolution systems than was previously practical, but also enhances its value and flexibility. Since coherence analysis is the basis of this new definition, and since the application of coherence procedures to high resolution data poses several problems, this report discusses these problems and their resolution.
Date: May 1, 1994
Creator: McDonald, T. S.
Partner: UNT Libraries Government Documents Department

Test definitions for the evaluation of seismic sensors.

Description: Most test methodologies referenced in this Test Definition and Test Procedures were designed by Sandia specifically for geophysical instrumentation evaluation. When appropriate, test instrumentation calibration is traceable to the National Institute for Standards Technology (NIST).
Date: July 1, 2007
Creator: Kromer, Richard Paul (R.P. Kromer Consulting, Albuquerque, NM); Hart, Darren M. & Harris, James Mark
Partner: UNT Libraries Government Documents Department