A Review on Relative Permeability Improvement in Gas Condensate Reservoirs Using Wettability Modifiers

Gas condensate reservoirs having bottomhole pressure below the dew point pressure show significant reduction in productivity over time. The loss in productivity is mainly due to the accumulation of condensates near wellbore. This phenomenon is recognized as condensate blockage or condensate banking. As pressure falls below the bubble point pressure, condensates come out of solution, causing a large reduction in both gas and condensate relative permeability. This paper introduces different methods to mitigate condensate blockage while focusing on a comprehensive review on wettability alteration as a common solution to the problem. Wettability alteration is performed using chemical treatment methods by wettability modifiers. Selecting the proper chemicals through screening process is a matter of considerable importance. Several authors have performed great experimental, simulation and modeling researches on this issue. This paper reviews the recent published papers published on the subject and provides some recommendations on application of nanofluids prepared with functionalized nanoparticles.