REGIONAL RESERVOIR CHARACTERIZATION IN THE APPRAISAL OF THE ALASKAN HEAVY OIL RESOURCE

Alaskan Heavy Oil is a significant resource to BP covering a large area: 14 Bbbl BP net over 1,600 sq. km.. Unfortunately, viscosities ranging between 200 – 20,000 cp mean this oil is immobile and inaccessible using conventional recovery techniques. Non-conventional recovery technologies (primarily thermal techniques) have been successfully developed and applied to Canadian heavy oil. BP-Alaska will appraise the appropriate recovery technologies and locations to demonstrate commercial development viability by executing a number of pilots. Successful selection of pilot locations and appraisal of pilot results require an understanding of compartmentalization and heterogeneities defined in a high quality reservoir characterization. A regional and local sequence stratigraphic framework has been established in this heterogeneous fluvial to shallow marine reservoir. Integration of well and merged seismic data produced depositional environment maps that predict reservoir quality and potential stratigraphic heterogeneity. Stratigraphic heterogeneity is an important constraint of pilot selection. Complex faulting patterns establish trap geometries and contribute to predicting additional compartmentalization. Maps of fluid type, viscosity, and areal distribution provide additional constraints for pilot selection. Geo-mechanical study results predict the behavior of the reservoir flow characteristics under changing thermal conditions. Acoustic rock properties and modeling studies predict 4D seismic attribute changes associated with pilot execution. The pilot selection process will utilize the reservoir characterization through a CRS mapping-based selection methodology.