Compressing the Processing Time-Line An Example from Block 14, Angola

Peter Mitchell¹ and Helmut Hsiao^2
1CABGOC, Luanda, Angola, Luanda, Angola
²Chevron Angola Block 14, Sugarland, TX

Exploration in Block 14 has undertaken an ambitious project to evaluate the remaining open acreage. In less then 20 months acquisition, processing, interpretation and analysis of 3-D seismic data will be completed, wells spud and tested. To meet the project goals, the processing timeline had to be significantly reduced while at the same time remaining adaptable to the needs of the interpreters. Several important issues further complicate this effort: 1. Survey size of 2700 Km² 2. The Congo River Canyon 3. Salt Bodies 4. Anisotropy 5. AVO 6. Legacy surveys totaling 2650 Km² The salt bodies and the Congo River Canyon necessitate the application of Pre-Stack Depth Migration, the AVO requires True Amplitude Processing while anisotropy and legacy surveys impact both amplitude and imaging. To compress the processing timeline several techniques were utilized; 1. A focus on noise suppression 2. Application of Exploration PSDM 3. Tomographic updates for velocity and anisotropy. 4. Post Migration processing for amplitude analysis 5. Interpretation driving the processing Applications of these techniques resulted in a 3-D seismic volume fit for exploration. Blue Books for four prospects were generated within 13 months of the start of acquisition. The process, however, did not result in a volume that would be sufficient for detailed development. This will require Full PSDM processing focused on at a discovery.

AAPG Search and Discovery Article #90072 © 2007 AAPG and AAPG European Region Conference, Athens, Greece