METHOD AND APPARATUS FOR DYNAMICALLY INVESTIGATING A BOREHOLE

摘要

AbstractAn apparatus and method for investigating a borehole withenergy transmissions whose directivity is varied in real timeduring the investigation is described. A plurality of transmittersare employed on a well logging tool with at least one receiverlocated ahead of the transmitters. The transmitters arerepetatively activated to transmit a wave of energy to thereceiver which produces a received wave. A parameter of thereceived wave is derived and used to vary the relative delayof activation of the transmitters to direct the beam of energyin a manner whereby the parameter is effectively enhanced fora subsequent investigation. A real time control is providedover the directivity of the energy transmissions to preferentiallyemphasize a particular segment of a received wave. An acousticborehole investigation is described with which the detection ofthe travel time of a compressional wave or the peak value ofa predetermined half cycle are optimized by controlling thedirectivity of the acoustic transmissions in real time.-1-