Abstract: Temperature and Pressure Anomalies Near the Red Fault, South Eugene Island Block 330, Gulf of Mexico

Francois-Dominique Cipriani, Dimas Coehlo, Lawrence Cathles, Sheila Roberts, Jeffrey Nunn

The South Eugene Island Block 330 reservoirs were filled with a billion bbls of oil and gas equivalent in less than 1.5 ma (age of the host sediments). Chemical differences between oils in individual reservoirs indicates that the oil was emplaced at different times. Recent pulses of hydrocarbon refilling may be reflected by temperature and pressure anomalies near the Red Fault and by apparent excess production of Pennzoil's reservoirs.

Finite element fluid flow models have been constructed that account for the strong permeability anisotropy of interlayered sands and shales, the influence of specific sands on fluid flow, the thermal anomalies produced by lithologic variations (especially salt), and the heat advection caused by changes in the sedimentation rate across faults. The calculations show that rapid flow of (approx.) 0.1 cu km of brine up the fault could produce temperature anomalies similar to those observed. This flow volume could also deliver about 1/4 of the "excess" oil and gas produced from Pennzoil reservoirs over the last 30 years if the brines were saturated in methane and transported oil in the same proportion to gas as is found today in the Block 330 reservoirs.

AAPG Search and Discovery Article #90986©1994 AAPG Annual Convention, Denver, Colorado, June 12-15, 1994