Abstract: Modeling Fluid Migration in the Offshore Louisiana South Eugene Island Block 330 Area

Lawrence M. Cathles, Roger N. Anderson, Jeffrey A. Nunn

The Global Basins Research Network is characterizing a volume of the Gulf Coast basin that is process-representative in terms of hydrocarbon generation and migration. This research has been made possible by the contribution of large amounts of industry data. At the same time we have developed data input and finite element modeling techniques. These techniques can realistically simulate processes such as sedimentation, erosion, diapirism, faulting, hydrocarbon maturation, fluid flow, temperature, chemical change, and interactions such as the dependence of permeability on pore fluid overpressure and fault movement. This modeling capability, called Akcess.Basin^TM, has been used to simulate: (1) the sediment loading, salt migration, faulting and fluid flow that occurred in offs ore Louisiana over the last 16 million years on a 300 km scale as the Mississippi delta prograded south, (2) the movement of salt from a sill into ridges and domes that occurred over the last 5 million years along a 120 km north-south section centered on South Eugene Island Block 330, and (3) the movement of fluids that has occurred in the last 2 million years within the sands, faults, and seals of the South Eugene Island Block 330 mini-basin. These nested models are capable of predicting present and past temperature distributions, the history of hydrocarbon generation and fluid flow, the history of overpressuring and compaction, and various kinds of chemical alteration. The main unconstrained variable is fault permeability. The fault permeability can ultimately be constrained by combini g the complete geologic data with realistic models of the coupled geologic phenomena.

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