Full text loading...
-
Benefit of Ultra-long Offset Data for Subsalt Imaging in Deep Water Gulf of Mexico
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 76th EAGE Conference and Exhibition 2014, Jun 2014, Volume 2014, p.1 - 5
Abstract
Summary
In the deep water Gulf of Mexico, wide azimuth (WAZ) data and the evolution of advanced imaging tools, such as TTI reverse time migration (RTM), have significantly improved the quality of subsalt imaging. By combining WAZ data with existing narrow azimuth data, imaging resolution is further improved.
However, subsalt imaging still remains difficult in areas with complex salt geometries, such as steeply dipping salt flanks and subsalt three-way closures. Full azimuth and long-offset acquisition is the latest acquisition technology to address subsalt imaging challenges. We analyze the impact of ultra-long offsets (up to 18 km) with 2D elastic modelling. Ultra-long offsets provide the ability to image steeply dipping subsalt events and undershoot complex salt geometry. With ultra-long offset field data extracted from a full azimuth survey, we also demonstrate that ultra-long offsets provide extra illumination power, helping image dipping subsalt events and improve the continuity of subsalt events in areas with complex salt geometry. Moreover, ultra-long offsets provide greater incident angle coverage in RTM 3D angle gathers, potentially aiding subsalt velocity updates.
© EAGE Publications BV