Geophone ground coupling effect on reservoir mapping

Abstract

Geophone ground coupling is one of the most important problems which holds the key to success of onland seismic exploration and puts restriction on all the constituent members of seismic data acquisition chain. In order to visualize the impact of this problem on finally processed 3-D seismic data and to provide the better feedback to practising geophysicists, an effort has been made to illustrate the consequences of coupling problem in interpretation if the geophone plantation is not monitored strictly during data acquisition. The 3-D data volume was acquired covering about 90 square kilometres area in Ramnad sub-basin of Cauvery basin, India and is processed using powerful 3-D processing sequence with adequate processing parameters. The pseudo interval velocity transform (PIVT) sections have been extracted from the vertical sections of 3-D data volume which pass through the drilled well. These PIVT sections for both good and poor geophone ground coupling conditions are interpreted in terms of encountered well lithology . Time slices at different levels have also been extracted from 3-D data volume and are analysed for good and poor coupling conditions. Finally, the implications of geophone ground coupling problem on 3-D seismic data applications for reservoir characterizations have been discussed in detail.