Application of Molecular Kinetic Theory (MKT) in Wettability Alteration of Reservoir Rock to Gas Wetting Using Nanofluid

Abstract

Summary During production from gas condensate reservoirs, significant productivity loss occurs due to condensate blockage after the pressure, near the production wells, drops below the dew point of the hydrocarbon fluid. Several remediation options exist for decreasing the impact of condensate blockage on the well deliverability including re-perforation, dry gas injection, hydraulic fracturing and etc. Recently, wettability alteration of reservoir rocks to gas wetting conditions is suggested to be more efficient in condensate blockage removal than other methods. In this study, a nanostructured emulsion of silicon-based molecules and fluoropolymer was used as a nanofluid to change the wettability of sandstone and carbonate rocks from liquid wetting to gas wetting. Molecular kinetic theory (MKT) was used to characterize the rock surface properties before and after treatment. The results show the sufficient efficiency of the nanofluid in changing the wettability of both carbonate and sandstone samples from liquid wetting to gas wetting. The distance between adsorption sites of the surface for treated and untreated surface rock was calculated using MKT method and dynamic contact angle. Results show that the distance between adsorption sites in the non-wetting condition is larger than that of the wetting case indicating wettability alteration.