A New Seismic Probe for Coal Seam Hazard Detection.
Peters-WR; Owen-TE; Thill-RE
Soc Min Eng AIME Preprint 85-312 1986 :7 pages
An experimental hole-to-hole seismic probe system has been developed for use in coal measure geology as a means of determining the structural conditions of coal seams. The source probe produces a 500-joule electric arc discharge whose seismic wavelet has a spectrum in the 200 to 2,000 hz frequency range. Low compliance hydrophones contained in the source probe as well as in a separate seismic detector probe are matched to the frequency range of the source. Both probes are constructed with 5.72-Cm-diameter housings. The transducers in the probes are equipped with fluid-inflatable boots to permit operation in either wet or dry boreholes. Preliminary tests in vertical boreholes drilled 213 m apart in sedimentary rock formations show reliable operation and useful seismic propagation measurements along horizontal and oblique paths up to 232 m in length. Because the seismic wavelet has an accurately repeatable waveshape, multiple shots and signal averaging techniques can be used to enhance the signal-to-noise ratio and extend the transmission distances.
Soc. Min. Eng. AIME Preprint 85-312, 1986, 7 Pp