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The AAPG/Datapages Combined Publications Database

AAPG Bulletin

Abstract


Volume: 64 (1980)

Issue: 5. (May)

First Page: 806

Last Page: 806

Title: Three-Dimensional Simulation of Geologic, Hydrodynamic, and Thermodynamic Development of a Sedimentary Basin--New Approach: ABSTRACT

Author(s): A. M. Yukler, D. H. Welte

Article Type: Meeting abstract

Abstract:

An understanding of paleopressures and paleotemperatures can guide and limit the application of geologic, geochemical, hydrodynamic, and thermodynamic principles in our study of the evolution of a sedimentary basin. Although we have qualitative understanding of the influence of paleopressure and paleotemperature on the interaction of sedimentation, compaction, and subsidence, a quantitative evaluation of the system is needed to understand basin history.

Accordingly, a three-dimensional, deterministic dynamic model was constructed to quantify mass and energy transport in sedimentary sequences of a basin. A new water flow equation was derived for a compacting porous medium under moving boundary conditions, and was coupled with the heat flow equation for the transfer of heat by conduction and forced convection (due to water movement). By varying heat flux, initial physical and thermal properties of sediments, paleobathymetric estimates and sedimentation rate, this model can compute pressure, temperature, and physical and thermal properties as a function of space and time.

Studies with this model show that pressure and temperature are closely interrelated with the geologic developent of a basin. Changes in heat flux alter relations between pressure and physical and thermal properties, and depth. For example, all the dependent and independent variables being equal, a change in heat flux affects the thickness of sediments in such a way that a 1,300-m thick clay layer subjected to a geothermal gradient of 40°C/km will compact to 1,236 m for an increase of 5°C/km, but will expand to 1,400 m with a decrease of 5°C/km to 35°C/km. Consequently, plots of pressure and physical and thermal data against depth are altered.

This dynamic model was successfully used to study a real basin. Pressures and physical and thermal data were computed with an error of less than 8%, and temperatures with an error of approximately 2°C, with respect to all other data.

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Copyright 1997 American Association of Petroleum Geologists