Modelling heat and fluid flow in sedimentary basins by the finite element method

Abstract

Abstract In this article we solve the equations for a 2D model of compaction of sedimentary basins saturated with water by the finite‐element method. This compaction model considers the rock described by the porosity as a function of effective stress, and both the anisotropic permeability and the anisotropic heat conductivity as functions of porosity. The water density is approximated linearly in the water pressure and temperature, and the water viscosity is a function of temperature. The main variables in the model are the water excess pressure and the temperature, and we account for an implicit solution scheme where we solve for both main variables simultaneously. The non‐linearities in the model are either dealt with by the Newton method or by fixed‐point iterations. We compare the coupled solution of temperature and pressure with the same decoupled equations. Then we study the contribution to the temperature by convection, the effect of the non‐constant water density, and some anisotropic case examples.