Abstract: Simulation and Modeling of the Hydrocarbon Generation-Migration-Mixing Processes in Louisiana's Sedimentary Basins

Ronald K. Zimmerman, Ying Shi

Mixed-age Mesozoic and Cenozoic hydrocarbons are present in many Louisiana oil and gas reservoirs. This phenomenon has added fuel to the controversy over whether the hydrocarbon source rocks underwent "shallow" or "deep" burial. Source rock generating capacities and timing of maturation, expulsion, and migration are important factors in providing a potential solution to the problem. The purpose of this paper is to reconstruct the dynamic processes of oil and gas generation-migration-mixing in Louisiana basins by using numerical simulation.

Problem solution employed a finite difference model which simulates numerically five processes on 2D vertical grids: (1) reconstruction of geological evolution as a result of sedimentation, erosion, and compaction; (2) computation of paleotemperatures based on constant crustal heat flow; (3) computation of source rock maturity based on a first-order kinetic model; (4) computation of geopressure based upon the result of compaction disequilibrium; and (5) computation of hydrocarbon expulsion and migration rates based on calculated results of maturity and geopressure reconstruction. This simulation/model yields plausible results for estimating potential regional reservoir volumetric distributions.

The integrated approach used in this study provides a means for analyzing the dynamic processes of oil and gas generation-migration-mixing in Louisiana's hydrocarbon systems. It also provides a basis for designing objective oil and gas trend analysis.

AAPG Search and Discovery Article #90950©1996 AAPG GCAGS 46th Annual Meeting, San Antonio, Texas