| 摘要 |
A seismic exploration method is disclosed for filtering the signals produced by a detector placed at different depths in a well in response to an emission of acoustic waves from a source on the surface: the signals comprising downgoing wave components and upgoing wave components. The filtering consists in sampling from among the N signals to be processed a group of n signals sl . . . sn detected at respective levels xl . . . xn, in determining the propagation time tk of the acoustic waves from the level xl to each level xk, in advancing the signals sk by the time tk in relation to sl and in adding sl and the signals sk thus shifted to obtain a sum zl, in calculating a sum yl of sl and of the signals sk delayed by the time tk in relation to sl, in generating a signal ul*, defined as an optimum estimation of the upgoing wave component, from the sums yl and zl, and in repeating these operations until the signal UN*-n+1 is obtained.
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