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CGG broadband acquisition system a success in Gulf of Mexico

23rd September 2013

CGG’s full-azimuth, long-offset towed-streamer marine broadband acquisition solution is delivering successful subsalt images in the Gulf of Mexico

CGG broadband acquisition system a success in Gulf of Mexico
StagSeis imaging from CGG’s multi-client IBALT survey in the Keathley Canyon area of the Gulf of Mexico. Courtesy of CGG Data Library

A year after its launch, CGG’s subsalt imaging solution, StagSeis, is delivering improved imaging and illumination in the Gulf of Mexico. The technology combines several advances in marine acquisition to provide full-azimuth, long-offset and broad-bandwidth data.

 

Early results from the multi-client IBALT survey merited a second survey, IBALT Deux, being commenced on its completion in January.

 

The configuration used for IBALT acquired offsets up to 18 km and full azimuths to 9 km. This survey was acquired over 221 full fold license blocks of Keathley Canyon in the Gulf of Mexico. About 10 per cent of this survey still remains to be shot, as a drilling rig is currently in the area, and will be acquired when the rig has vacated.

 

The second StagSeis acquisition, IBALT Deux, is currently underway, covering 357 adjacent blocks and is scheduled for completion in October.

 

StagSeis is a multi-vessel acquisition technique which combines several tried and tested marine acquisition solutions, such as BroadSeis variable-depth streamers for broad bandwidths, continuous overlapping recording for longer records and Dovetail fanned acquisition for reduced infill.

 

By combining full azimuths and long offsets with broadband technology, it is also possible to obtain ultra-low frequencies for subsalt imaging.

 

Stagseis employs two multi-streamer vessels and three additional source vessels in a proprietary staggered configuration. Sail lines are acquired in an anti-parallel fashion in two orthogonal passes, allowing data to be acquired with four axes of ultra-long offsets up to 20 km and full azimuths up to 10 km.