Improvements to the seismic exploration Technique for installation of vertical Seismic Profile

摘要

Seismic exploration method 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 . . . sk detected at respective levels xl . . . xk, 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 combining sl and the signals sk thus shifted and advanced to obtain a signal zl, where the downgoing wave component is accentuated, in calculating from sl and the signals sk delayed by the time tk in relation to sl, a signal yl, where the upgoing wave component is accentuated, in generating a signal ul*, defined as an optimum estimation of the upgoing wave component, from the signals yl and zl, and in repeating these operations until the signal uN*-n+1 is obtained. Figure 3.