Correcting Oil-Water Relative Permeability Data For Capillary End Effect In Displacement Experiments

Abstract

By neglecting the effect of capillary forces, the relative permeabilities calculated by the method of Johnson, Bossler, and Neumann or Jones and Roszelle from low rate displacement experiments are in error.<p> In this study, steady state and displacement experiments were carried out. A history matching package along with a fully implicit numerical simulator and a Welge type model were developed and the displacement data were analyzed by history matching to quantify these errors. A modified centrifuge drainage bucket was used to obtain drainage and imbibition capillary pressure data.<p> The results show that in the case of drainage the non-wetting phase end point relative permeabilities and saturation exponents increase with an increase in rate. However the saturation exponent for the wetting phase decreases with rate. The wetting phase end point relative permeability stayed more or less constant with rate. In the case of imbibition these parameters did not indicate any meaningful rate dependent trend. <p>