AMPLITUDE COMPENSATION OF SEISMIC DATA - APPLICATION TO MASKING BY SHALLOW BRIGHT SPOTS

True amplitude seismic data are desired for seismic interpretation bec ause they contain direct hydrocarbon indicators. Amplitudes of reflect ions from deeper target zones are often differentially weakened and di storted by the spatially variable transmission and intrinsic attenuati on (Q) losses in the overlying layers. A compensation function for tra nsmission loss is directly estimated from the reflections recorded in surface seismic traces. To obtain the compensation function for attenu ation loss, Q needs to be estimated a priori. This method is first tes ted on synthetic zero-offset data, then applied to a real 3-D stacked volume in which the target zone is masked by a group of shallow bright spots. This is a very efficient, physically-based algorithm that give s visually balanced amplitudes that are close to true relative amplitu des along the deeper target reflections.