Print this pageAAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Great White “WM12” Reservoir: A New Development in the Ultra-Deepwater, Perdido Fold Belt, Gulf of Mexico
(1) Shell E&P Americas, Houston, TX.
The Great White Field (Alaminos Canyon Block 857) is located in the Perdido Fold Belt of the southwestern Gulf of Mexico. The ultra-deepwater development is a joint venture between Shell, BP, and Chevron. Eight exploration and appraisal wells and six development wells have been drilled, with initial field development efforts focused on the Upper Wilcox (Eocene) “WM12” sand. In March 2010, the first Paleogene production in the GOM was initiated from the WM12 at the Shell-operated Perdido Spar in 7800 feet of water.
The WM12 sand is a proximal turbidite lobe sequence, comprised predominantly of high quality, amalgamated sheet sands with minor thin shales and calcite-cemented zones. Availability of high-quality 3D seismic has been instrumental in the interpretation of reservoir extent, fluid-fill, and faulting at the WM12 objective. Great White is structurally very complex, with over 200 faults interpreted at the WM12 level. Consequently, compartmentalization is considered to be the primary risk to reservoir and well performance. Uncertainty related to the number and transmissibility of faults, downdip limit of hydrocarbons in untested fault blocks, and prediction of reservoir quality away from well control have presented significant challenges for reservoir modeling and field development planning.
Results from a suite of WM12 reservoir models were used for input into an “Experimental Design” to capture the range of in-place and recoverable volumes and form the basis for a staged field development plan. The initial stage includes 13 producers and a targeted waterflood with 4 injectors in the large WM12 “Main” fault block. Contingent on drilling results and production performance, subsequent development in the WM12 will include wells in more complex areas of the field and expansion of the waterflood in up to three additional reservoirs. Given success, the Great White WM12 development program will ultimately include a total of 21 producers and 9 water injectors.
The high quality 3D seismic and extensive petrophysical and reservoir dataset gathered during exploration and appraisal drilling has enhanced the predictions of sand quality, thickness, and hydrocarbon distribution. Reservoir thickness and quality in the initial six WM12 development wells has met or exceeded expectations. A comparison of pre-drill estimates and early well results, as well as an update of well performance will be shown.