WATS it take to image an oil field subsalt offshore Angola?

Abstract

Abstract BP's exploration success in deepwater Block 31, offshore Angola, has been driven by conventional narrow-azimuth 3D seismic data coupled with the latest available imaging algorithms. However limitations in these data are now apparent and the data is deemed insufficient for the appraisal and development of the subsalt discoveries in the western part of the block. 3D acoustic finite-difference modelling was applied to Block 31 to evaluate the potential data quality uplift from a wide-azimuth towed streamer (WATS) survey. Results showed that a significant improvement in data quality is possible. The modelling also investigated key acquisition variables (acquisition direction, sail line separation, number of tiles, cable length) to arrive at a solution that optimized both data quality and cost. Acquisition of this survey began in December 2008 and it is expected to complete in August 2009. This is the first WATS seismic survey outside the Gulf of Mexico and the first in Angola.