DEVICE AND METHOD FOR TRANSMITTING ACOUSTIC WAVE INTO UNDERGROUND, FOR RECEIVING THE ACOUSTIC WAVE, AND UNDERGROUND EXPLORATION METHOD USING ABOVE MENTIONED DEVICE

摘要

On the transmitting side, a piezoelectric device (34) is so provided that the transmission direction is vertical to the wall of an exploration well (12). An anvil (42) provided on the exploration hole wall side of the piezoelectric device is pressed against the wall of the investigation well by a clamping mechanism (64). On the receiving side, the upper and lower parts of an exploration well (112) are closed with a packer (182) and a shut-off valve (180) to block the flow of fluid, and a cable (150) above a receiver is fixed to the wall of the exploration well by a clamping mechanism (164) to reduce noise propagated through the cable. The measured depth and the distance between the exploration wells in oil exploration and soil survey using acoustic tomography can be increased and the applicable range can be widened.