| 摘要 |
<p>A method and apparatus for acquiring acoustical data from a borehole (10) and is especially useful in carrying out tomography surveys. The borehole digital geophone (BDG) tool (14) of the present invention is capable of operating from a standard, 7-conductor logging cable (16) with no special cables being required since the individual digital geophone modules (DGM) (15a-e) which form the BDG tool (14) are connected together by short, separate lengths of the same 7-conductor cable (16). Each DGM acquires, digitizes, stacks, and stores data generated by its own three-component geophone (37) assembly prior to transmitting these signals to the surface over a dedicated conductor (7) in the cable thereby substantially increasing the sample rate of the tool which, in turn, substantially reduces the field time to run a tomography survey.</p> |
