Full-azimuth imaging using circular geometry acquisition
Full-azimuth imaging using circular geometry acquisition (in Seismic acquisition, Tim Brice (prefacer) and Jeff Deere (prefacer))
Leading Edge (Tulsa, OK) (July 2008) 27 (7): 908-913
- anisotropy
- Atlantic Ocean
- Cenozoic
- data acquisition
- data processing
- deep-water environment
- geometry
- geophysical methods
- geophysical surveys
- Gulf of Mexico
- imagery
- instruments
- marine methods
- North Atlantic
- ocean floors
- seismic methods
- streamers
- surveys
- Tertiary
- wide-azimuth tower streamers
- circular acquisition geometry
Wide-azimuth (WAZ) towed-streamer acquisition has improved the quality and reliability of subsalt imaging in the Gulf of Mexico, where WAZ surveys have typically been acquired using 3-4 seismic vessels, each shooting in straight parallel lines. However, acquisition of WAZ data using a single vessel and a circular geometry offers several potential advantages, both for operational efficiency and geophysical analysis of subsurface rock properties. Modeling exercises indicate that circular acquisition geometry can deliver a better range of azimuths and offsets than parallel WAZ geometry. A feasibility test in the Gulf of Mexico shows that it is possible to sail along circles while maintaining constant streamer separation and achieving very accurate receiver positioning. Single-sensor recording enables effective attenuation of the additional coherent noise introduced by shooting in a curve. Prestack depth-migrated data from the circular geometry test compare favorably with a parallel geometry WAZ data set acquired previously.
