CLEMENCEAU, GEORGE, and JASON COLBERT, Amoco Production Co., New Orleans, LA, USA

Abstract: Levee-overbank Turbidite Production from Ram/Powell Field, Deepwater Gulf of Mexico

Recent development drilling and production data from the "L" reservoir in the Ram/Powell Field has provided a better understanding of how levee-overbank reservoirs can perform. Reservoir connectivity is thought to be a significant risk in the more complicated architecture of submarine fan channel-levee and levee-overbank facies sands. However, production results from a single horizontal well in this sand suggests connectivity over the entire 4000 acre reservoir is possible.

The "L" sand contains ~18% of the ~300 MMBOE total Ram/Powell Field reserves contained in three main reservoirs,"J","L", and "N" sands. The "L" reservoir is thought to be trapped entirely within levee-overbank facies. Some major differences between proximal and distal levee are noted; the proximal levee averages ~60% net sand, whereas the distal levee averages ~27%. Core and dipmeter data indicate a complex architecture that changes away from the channel margin, from sets of increasing and decreasing dip patterns in the proximal levee, to more constant low angle dips in the distal levee. A similar complicated architecture can be seen in some thin-bedded levee outcrops. Though rock quality is good, flow unit barriers due to interbedded silts and mudstones, were expected to reduce well performance.

Gas production has outperformed rate predictions of 70-80 MMCFD. One possible explanation for the better than expected connectivity is the suspected presence of sand-on-sand cut and fill architecture as suggested by cores and dipmeter logs.

AAPG Search and Discovery Article #90923@1999 International Conference and Exhibition, Birmingham, England