Wave separation procedure for borehole seismics with walk away acquisitions

摘要

Method for separating waves propagating in a medium comprises comparing the first collections of signals (C) to estimated signals. A slope (p) is then applied to each point on a pivot trace at depth (z) and the amplitudes of the trace at each point are added. A synthetic seismograph is generated from the slopes and compared to the real one until, by iteration, an acceptable model is produced Method for separating waves propagating in a medium comprises generating waves in the medium successively from several positions from at least one emitter on the surface of the medium, and receiving the waves on at least one receiver which can occupy at least two positions successively in a shaft drilled in the medium. Each receiver contains three data capture units oriented along three axes (V, H1, H2). One of these axes (V) is along a set direction, each unit produces a signal which is recorded as a function of time in the form of a trace which is identified by the positions of the emitter/receiver pairing producing that trace; making collections of traces from a common emitter from at least one set of traces V, H1, H2. An angular polarization SIMILAR z, angular azimuth SIMILAR g, angle of deviation SIMILAR u and azimuth SIMILAR h are calculated for each emitter/receiver pair in the time/slope domain.