Preliminary results of a seismic borehole test using downhole shaped charges at the DOE Hanford Site
- Westinghouse Hanford Co., Richland, WA (United States)
- Oyo Geospace Corp., Houston, TX (United States). Engineering Geophysics Div.
Geophysical site characterization studies can be important steps in the process of designing and monitoring remediation at hazardous waste storage facilities. Use of seismic techniques for subsurface characterization at the DOE Hanford Site has been limited. One reason is the lack of borehole velocity control, and low-velocity sediments are highly attenuative. Consequently, standard techniques to provide velocity control are not adequate. Both Vertical Seismic Profiling and reversed VSP surveys are currently being investigated to provide velocity control and for subsurface imaging capabilities. Recently a jet perforating gun was used to perforate a doubled-cased borehole in the 200 West Area. Acoustic emissions were recorded from numerous depths to obtain velocity control for a previous surface survey conducted in the same area. Both P- and S-wave data were recorded simultaneously from multiple horizons using the DAS-1 seismograph and 3-component geophones. The data were analyzed for a variety of uses besides velocity control. Signal attenuation was studied as a function of source depth and offset distance to evaluate formation absorption while vertical resolution was determined from the frequency spectrum. Preliminary results indicate that adequate P-wave velocity control can be obtained even though the near-surface sediments are very attenuative. However, we conclude that the perforating gun produces little SH energy. Preliminary velocities indicate that reflection coefficients should be great enough to use surface techniques. Results from the frequency study suggest that a swept source for both surface and borehole surveys may be necessary to obtain required resolutions. Finally, signal attenuation as a function of formation facies suggest that seismic techniques may be useful in mapping perched water zones and for long term vadose zone monitoring.
- Research Organization:
- Westinghouse Hanford Co., Richland, WA (United States)
- Sponsoring Organization:
- USDOE, Washington, DC (United States)
- DOE Contract Number:
- AC06-87RL10930
- OSTI ID:
- 10133093
- Report Number(s):
- WHC-SA--2304; CONF-940353--4; ON: DE94008077; BR: 35AF11201/35AF11202
- Country of Publication:
- United States
- Language:
- English
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Related Subjects
11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS
54 ENVIRONMENTAL SCIENCES
540250
58 GEOSCIENCES
580000
ACOUSTIC MEASUREMENTS
BOREHOLES
GEOSCIENCES
HANFORD RESERVATION
HEALTH AND SAFETY
RADIOACTIVE WASTE FACILITIES
REMEDIAL ACTION
SEISMIC P WAVES
SEISMIC S WAVES
SEISMIC SOURCES
SEISMIC SURVEYS
SHAPED CHARGES
SITE RESOURCE AND USE STUDIES
UNDERGROUND EXPLOSIONS