Integrated Modeling of Basin Fill, Paleohydrology, and Hydrocarbon Migration: Exploration Application in the Gulf of Mexico

Abstract

In an ongoing effort to improve understanding of hydrocarbon accumulations in the Gulf of Mexico, the authors are evaluating the extent to which computer models of basin fill, thermal history, and paleohydrology can be used to develop exploration models for hydrocarbon generation, migration, and entrapment through time. As a part of the evaluation, they have developed paleoreconstructions for three regional cross-sections from south Texas, east Texas, and central Louisiana showing the dynamic evolution of the structural trap/timing, paleopressure history, hydrocarbon maturation, and fluid migration pathways from Jurassic to present day. The basin scale of the cross-sections is typified by the central Louisiana line that extends 746 mi from southern Arkansas to the Sigsbee abyssal plain. To help constrain the models, they collected pressure, temperature, and fluid chemistry data and assessed the geochemistry and thermal maturity of potential source rocks and oils. An important exploration implication of the basin models is the suggesting that timing of peak paleopressure development and peak hydrocarbon generation and migration vary across the gulf. Such variations in timing of overpressure and migration have significant implications for different trap fill histories and exploration models for major Oligocene reservoirs in these areas. Once the regional scale models are more » constructed, any area or interval of exploration interest, such as the Oligocene or Miocene of Louisiana, can be evaluated. Boundary conditions for parameters such as heat flow or fluid flow are extracted from the regional model and then applied to a play or prospect scale model. « less