Identifying New Petroleum Systems Using Regional PSDM Data in Deep Water East India

Steven G. Henry¹, Al Danforth², and Sujata Venkatraman^3
1Innovative Exploration Services, Las Cruces, NM
²Consultant, Houston, TX
³ION, Houston, TX

Deep (25 km), large source, long offset (10 km) pre-stacked depth migrated (PSDM) seismic data is proving to be a very useful emerging exploration technology for identifying potential new petroleum systems in complex deep water settings. Exploration in these frontier areas typically lacks well control, and estimating lithologies associated with source rocks, reservoirs and seals and the other components needed to define an active petroleum system is risky. PSDM data can reduce this risk by improving the imaging of reflectors in areas with laterally varying velocities (salt, water bottom), revealing faults, stratal relationships and possible direct hydrocarbon indicators in their more correct geometric configurations.

Long (400 km dip, 2000 km strike) regional PSDM seismic data was acquired in the deep water along the East Indian continental margin. This data imaged to over twice the depth of existing data and has significantly higher resolution that has been used for identifying new petroleum systems. Two examples will be presented that have greatly increased India’s exploration potential. The first is the 85E Ridge, previously thought to be a hot spot track, and now interpreted to be a continental fragment supporting a very large (50 x 100 km) carbonate platform, underlain by potential Jurassic through Cretaceous source rocks. The second example is a large deep (15-20 km) coastal graben that likely contains Albo-Aptian source rocks in the active oil generation window. As illustrated here and continuing into the future, regional PSDM seismic data will be critical for developing new plays in frontier deep water areas.

AAPG Search and Discovery Article #90078©2008 AAPG Annual Convention, San Antonio, Texas