COUPLED GEOCHEMICAL-BLACK OIL CARBONATE RESERVOIR NUMERICAL MODELING AND SIMULATION OF LOW SALINITY WATER INJECTION

In an increased World demand for more oil, enhanced oil recovery method is gaining more and more attention as a determinant factor for increasing the oil recovery. Low salinity of injected water can increase oil recovery and can change the wettability of carbonate reservoirs from oil wet to water wet or in the worst case in mixed oil-water wet. The mechanism is not understood very well because of complex physical and chemical phenomena. Some studies link the mechanism of change of wettability for less oil wetting phase during low salinity with the potential data of carbonates. The interface of oil-brine and rock-brine, at lower salinities for carbonates-brine charges of the interface becomes more negative because of weaker electrostatic adhesion forces. In this work a numerical model was developed coupling between MRST Software and PhreeqcRM-a software of American Geological Survey. PhreeqcRM operates in 2D and 3D and is an advance module of Phreeqc, which is available only for 1D cases. In this work the PhreeqcRM module will be coupled with the stochastic Lagrangian random walk method that is a synonym of the classical advection dispersion equation. The main objective is to develop a model for understanding the impact of geochemical interactions between the injected low salinity water and the dissolution of calcite rock mineral, which is the most representative of carbonate reservoirs.