| 摘要 |
FIELD: oil and gas production. ^ SUBSTANCE: probe systems of k probes of various depth of lateral logging simultaneously fed with k sources of alternate current with frequencies f1Çfk excite alternate electric fields in borehole and in surrounding rock. Summary signals of current and of potential of a central electrode of probe systems are divided into frequency constituents by means of band filters included into measuring channels of current and potential of the central electrode. Specific electric resistance measured with k various depth probes of lateral logging are determined by frequency constituents of current and potential of the central electrode. To eliminate interference of probes there are used k rejecter filters included into output circuits of each source of alternate current. Frequencies f1,Çfk are chosen with consideration of meeting conditions for maintaining quasi-stationarity of excited electric fields and, in particular ratio f1>f2>Ç>fk, where bigger radial depth of survey of lateral logging probing corresponds to a bigger index k. ^ EFFECT: expanded functionality of lateral logging of various depth. ^ 2 cl, 1 dwg |
