From Euphoria to Reality: One Operator's Experience with Reservoir Performance in the Deepwater Gulf of Mexico
Bret D. Hampton, Thomas V. Wilson, and Robert Crookbain
Shell International E&P, New Orleans, LA
In the early stages of the GOM deepwater play (early to mid 1990's), Shell's development efforts were focused on large, amplitude-supported, high quality reservoirs such as Bullwinkle, Auger and Mars. These developments, which yielded wells with high rates (>10,000 BOPD) and large per-well ultimates (>10MMBO), spurred a euphoric frenzy of E&P industry deepwater activity with less than appropriate concern for differentiating deepwater reservoirs according to their performance characteristics. As the play matured into the late 1990's, Shell and others began developing smaller reservoirs in more stratigraphically and structurally complex settings. The production performance from these reservoirs spanned the full range from high rate, high ultimate wells (e.g. Ursa) to wells that died within days of being brought online (e.g. Oregano). The mixed production performance introduced a healthy dose of reality and re-emphasized the need for a more thorough understanding of intra-reservoir architecture. Current efforts are directed at improving our performance predictions by understanding which aspects of the detailed reservoir architecture have a significant impact on production performance. The reality is that more accurate performance predictions require an improved understanding of the subtle geologic details. As we proceed to develop complex, poorly imaged fields and new plays, we must continue to gather the basic data to improve our performance predictions and to appropriately represent the uncertainty.