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Title: Seismic sources

Abstract

Apparatus is described for placement in a borehole in the earth, which enables the generation of closely controlled seismic waves from the borehole. Pure torsional shear waves are generated by an apparatus which includes a stator element fixed to the borehole walls and a rotor element which is electrically driven to rapidly oscillate on the stator element to cause reaction forces transmitted through the borehole walls to the surrounding earth. Longitudinal shear waves are generated by an armature that is driven to rapidly oscillate along the axis of the borehole, to cause reaction forces transmitted to the surrounding earth. Pressure waves are generated by electrically driving pistons that press against opposite ends of a hydraulic reservoir that fills the borehole. High power is generated by energizing the elements for more than about one minute. 9 figs.

Inventors:
; ; ; ;
Issue Date:
Research Org.:
Lawrence Berkeley Lab., CA (USA)
OSTI Identifier:
7098834
Patent Number(s):
-US-A6039887
Assignee:
LBNL; ERA-14-001601; EDB-88-186314
DOE Contract Number:  
AC03-76SF00098
Resource Type:
Patent
Resource Relation:
Other Information: Portions of this document are illegible in microfiche products
Country of Publication:
United States
Language:
English
Subject:
47 OTHER INSTRUMENTATION; 58 GEOSCIENCES; SEISMIC SOURCES; DESIGN; BOREHOLES; INVENTIONS; P WAVES; S WAVES; SEISMIC SURVEYS; SEISMIC WAVES; CAVITIES; GEOPHYSICAL SURVEYS; PARTIAL WAVES; SURVEYS; 440400* - Well Logging Instrumentation; 580203 - Geophysics- Geophysical Survey Methods- (1980-1989)

Citation Formats

Green, M.A., Cook, N.G.W., McEvilly, T.V., Majer, E.L., and Witherspoon, P.A. Seismic sources. United States: N. p., 1987. Web.
Green, M.A., Cook, N.G.W., McEvilly, T.V., Majer, E.L., & Witherspoon, P.A. Seismic sources. United States.
Green, M.A., Cook, N.G.W., McEvilly, T.V., Majer, E.L., and Witherspoon, P.A. Mon . "Seismic sources". United States.
@article{osti_7098834,
title = {Seismic sources},
author = {Green, M.A. and Cook, N.G.W. and McEvilly, T.V. and Majer, E.L. and Witherspoon, P.A.},
abstractNote = {Apparatus is described for placement in a borehole in the earth, which enables the generation of closely controlled seismic waves from the borehole. Pure torsional shear waves are generated by an apparatus which includes a stator element fixed to the borehole walls and a rotor element which is electrically driven to rapidly oscillate on the stator element to cause reaction forces transmitted through the borehole walls to the surrounding earth. Longitudinal shear waves are generated by an armature that is driven to rapidly oscillate along the axis of the borehole, to cause reaction forces transmitted to the surrounding earth. Pressure waves are generated by electrically driving pistons that press against opposite ends of a hydraulic reservoir that fills the borehole. High power is generated by energizing the elements for more than about one minute. 9 figs.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1987},
month = {4}
}