Abstract

The use of 2D hydrocarbon generation and fluid flow modeling, drainage polygon analysis on key migration surfaces, coupled with geochemical information, can be a powerful integration process for understanding a petroleum system. Integrated, these tools can be used postmortem to explain dry holes and in a forward model mode to risk and rank new prospects and plays in an area. 2D hydrocarbon generation and fluid flow modeling provides the detail to test the geologic model that will control migration style (eg. bed lateral vs. vertical) and the hydrocarbon phase distribution. Most 2D generation and fluid flow models do not allow for accurate migration modeling in structurally complex areas through time. However, modeling structurally paleotectonic restored sections at key hydrocarbon expulsion time steps during basin evolution can circumvent this problem. 2D models are commonly performed on seismic lines, which are often not on the main fluid migration pathways and 2D models do not take into account "out of the plane" migration effects. Drainage polygon analysis allows volumetrics to be more easily determined for prospect charge and account for "out of the plane" migration effects. However, integration of geochemical and well data (ie. oil stains and oil families) and 2D model results is often necessary to determine the correct migration surface for drainage polygon analysis of a given prospect, especially in structurally complex inverted basins. A couple of examples from a regional study of integration of 2D modeling, using IES Petromod and the Conoco "Drainage Polygon" programs, applied to postmortem, prospecting and risk assessment are given for the Bawal graben and Bintang Laut areas in West Block B PSC.