Reservoir pressure and seafloor venting: Predicting trap integrity in a Gulf of Mexico deepwater turbidite minibasin

摘要

Pore pressures in two sands equal the least principal stresses in the overlying shale seals in the Popeye-Genesis deepwater Gulf of Mexico minibasin, located in lease Blocks GC72 and GC205. We interpret that sand pressures are dilating fractures in the cap rock and inducing fluid migration from the crest. These leak points limit the sand pressure to the least principal stress at its crest and ultimately ensure the integrity of the hydrocarbon traps at the offset Genesis and Popeye fields. Mud volcanoes, gas hydrates, and biological vent communities overlie the leak points. In overpressured basins with significant structural relief, pore pressures may converge on the least principal stress at the structural crests. When this occurs, fluid pressures can be predicted throughout a hydraulically connected reservoir volume, and this can be used to estimate trap integrity and potential column heights and to design safe and economic drilling programs.