Imaging Complex Geology from Seismic Data

Alvin K. Benson

Imaging reflections at their proper positions when the subsurface structure is complex requires two equally important factors: (1) a high quality estimate of the interval velocity and (2) a sophisticated algorithm that can properly apply detailed velocity information to unimaged data. One approach to obtaining the velocity distribution is self-consistent iterative modeling. Using any existing data or information, synthetic models can be progressively generated until a close match is made with the original data. The final velocity distribution in this scheme then supplies the velocities for a depth imaging algorithm.

A variety of explicit and implicit imaging schemes can be devised and implemented. These algorithms provide a variety of options for imaging complex geology by handling steeper dips and abrupt lateral velocity changes. In particular, by viewing the collected data from a rotated coordinate system, rotational depth imaging can image dips up to 90°. Immediate applications can be made to thrust belt problems, delineating the edge of a salt dome and additional reservoirs around the salt dome edge, etc.

AAPG Search and Discovery Article #91040©1987 AAPG Rocky Mountain Section Meeting, Boise, Idaho, September 13-16, 1987.