David Bartel2, Casey Simms3, Peter Mitchell3,
Henry Megan2 (1) ChevronTexaco
Overseas Petroleum Co, Houston, TX (2) ChevronTexaco Energy Technology Company
Traditional interpretation of seismic gathers is based on
arbitrary traverses that display stationary information over features such as
fluid changes. In Block 14, deepwater
The technique uses vertical planes that correspond to constant offset seismic panes, which are panned in a crossline direction allowing for dynamic near to far offset comparison of the data. The use of traditional in-line gather displays, including arbitrary traverses, is also possible. Furthermore, stacked-data seismic interpretation such as faults, horizons and oil/water contacts, can also be loaded and compared with the dynamic response of the seismic data as near to far offsets are panned.
We illustrate examples of how these techniques have been applied by the operator (CABGOC, a ChevronTexaco affiliate) in association with other members of the Block 14 Contractor Group (Sonangol P&P, ENI, Total and GALP) to the deepwater Negage and Lobito fields in Block 14 Angola.
Applications of this method include (1) validation of seismic processing flows including moveout corrections, (2) detection of multiple interference, (3) comparison of velocity models over the predicted oil/water contact surfaces, (4) validation of the high- or low-imped-ance nature of reservoirs, (5) identification of phase changes resulting from Earth interaction as opposed to poor moveout, (6) selection of features that should be mapped on a given stack (7) identification of exploitation opportunities by extension of known hydrocarbon responses.