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Home > JOGMEC's Activities > Technology Development and Technical Support (Oil and Natural Gas) > Oil & Gas Reservoir Detection and Characterization : Prestack Depth Migration (PSDM)

Prestack Depth Migration (PSDM)

Prestack depth migration (PSDM) is a key seismic technology for improving oil discovery in global oil exploration, especially where geological heterogeneity such as salt domes and fault complexity prevent optimal seismic imaging. Since interpretative geological modeling plays an essential role in PSDM quality, JOGMEC is dedicated to developing case-dependent processing technologies and to accumulating experience and know-how for solving individual problems.

Prestack Depth Migration (PSDM) for Complex Subsurface Structures

PSDM is a model-based seismic imaging methodology that works well for complex geological structures such as subsalt layers and basement fractures. Compared to conventional time migration image processing, which assumes that seismic waves are propagated in straight rays, PSDM is more expensive and time consuming but is more likely to precisely determine the structure of oil and gas reservoirs.

JOGMEC has conducted PSDM not only for salt domes, but also for overburden velocity heterogeneity which is dispersed in offshore northwest Australia and offshore Abu Dhabi. This has allowed us to image oil reservoir structures precisely and uncover the existence of faults. We have also developed customized PSDM software for basement fault imaging in basement fracture reservoirs offshore Vietnam, which contributed to oil discovery.

Although PSDM image processing is now widely offered by many leading geophysical contractors, it has sometimes failed to deliver successful results. Obtaining highly precise results from PSDM processing requires interpretative velocity modeling, in addition to processing technologies. Expertise in integrating processing and interpreting techniques is key to constructing optimal velocity models. JOGMEC has acquired extensive expertise in PSDM processing through joint study projects with several operating companies.