Parameters on Reconstructions of Geohistory, Thermal History, and Hydrocarbon Generation History in a Sedimentary Basin

S. Cao, Ian Lerche

Geological processes related to petroleum generation, migration, and accumulation are very complicated in terms of time and variables involved, and are very difficult to simulate by laboratory experiments. For this reason, many mathematic/computer models have been developed to simulate these geological processes based on geological, geophysical, and geochemical principles. Unfortunately, none of these models can exactly simulate these processes because of the assumptions and simplifications made in these models and the errors in the input data for the models.

The sensitivity analysis is a comprehensive examination on how geological, geophysical, and geochemical parameters affect the reconstructions of geohistory, thermal history, and hydrocarbon generation history. In this study, a one-dimensional fluid flow/compaction model has been used to run the sensitivity analysis. We will show the effects of some commonly used parameters such as depth, age, lithology, porosity, permeability, unconformity (time and eroded thickness), temperature at sediment surface, bottom hole temperature, present day heat flow, thermal gradient, thermal conductivity and kerogen type, and content on the evolutions of formation thickness, porosity, permeability, pressure with time and depth, heat flow with time, temperature with time and depth, vitrinite reflectance (R_o) and TTI with time and depth, oil window in terms of time and depth, and amount of hydrocarbon generated with time and depth.

AAPG Search and Discovery Article #91030©1988 AAPG Annual Convention, Houston, Texas, 20-23 March 1988.