Unsteady State Relative Permeability and Capillary Pressure Estimation of Porous Media

To take capillary effect into account, a series of primary drainage experiments of water by a sample oil fluid have been studied. The experiments performed under different low flow rates on a horizontal glass type micromodel as a model of porous media. Based on conventional macroscopic flow equations, the relative permeabilities and capillary pressure are determined by parameter estimation technique from history matching of saturation and pressure data of unsteady state immiscible displacements. The Coery type of relative permeability and capillary pressure functions are used. The results show that the end point relative permeability of oil phase and the dynamic term and the exponent of capillary pressure function increase with flow rate, but the saturation exponent of relative permeability functions are decreasing with flow rate. Also the results show that the capillary pressure and relative permeability curves are rate dependent and the relative permeability curves are increasing with flow rate.