APPROACH TO MATHEMATICAL MODELING OF RESERVOIR SALT DISSOLUTION USED IN THE HYDRODYNAMIC SIMULATOR TECSCHEME

Abstract

The relevance of the research is caused by the need to modeling the process of dissolution reservoir salt during flooding of hydrocarbon deposits, taking into account changes in the filtration-capacitance properties of the reservoir rock on the amount of undissolved salt and the physical properties of the aqueous phase on the amount of salt dissolved in it. The main aim of the research is to develop a mathematical model of fluid filtration in reservoirs, taking into account the reservoir salt dissolution in the aqueous phase and providing for the possibility of finding a salt solution in the aqueous phase in saturated and unsaturated states. The object of the research is the solution of the equation of three-phase three-dimensional fluid filtration in reservoirs containing undissolved salt, accompanied by the change in the density and viscosity of the aqueous phase depending on the amount of salt dissolved in it and the change in the porosity and permeability of the reservoir rock when the reservoir salt is dissolved. Methods: numerical solution of differential equations systems of the Masket–Meres non-volatile oil model using the implicit pressure explicit saturation method. Results. Using the developed mathematical model of salt dissolution, a test problem was calculated, during which the geological reserves of undissolved salt, the mineralization of reservoir water, amount of dissolved salt and average concentration of dissolved salt in the aqueous phase were determined when changing input parameters such as the salt dissolution rate constant and the maximum allowable salinity and concentration of salt solution. It is shown that the results of numerical modeling correctly describe the processes occurring during the dissolution of the reservoir salt and do not contradict the physical concepts of this process.

Keywords

• mathematical model
• hydrodynamics
• numerical methods
• deformable porous media
• filtration
• salt dissolution