Experimental Study of the Interaction Between Oil and Reservoir Rock on the Relative Permeability and Wettability

Abstract

Summary One of the fundamental parameters in the fluid flow in porous media is the rock-fluid interaction that affects the wettability and fluid flow pattern. In this study, three crude oil samples from an oilfield of southwest Iran were selected to investigate the bonds and interaction between oil and calcite reservoir rock. The results of relative permeability and contact angle measured for each sample demonstrate that residual oil saturation and oil spread over the rock surface are different for each oil sample. According to the results of Fourier transform infrared (FTIR), the oil sample with higher intensity of O-H stretch band on the rock surface raises the interaction and bonding and shifts the rock towards oil-wetting. In addition, the presence of aromatics with high concentration in oil samples and the existing bonds on rock indicates the high importance of these compounds in oil adsorption on reservoir rock surface. Moreover, the relatively polar S-H stretch bonds have a slight impact on oil adsorption and create a weak bond with the rock surface. Based on the results of this study, the potential of bonding and rockfluid interaction in porous media to be estimated in terms of wettability alteration and fluid flow regime.