Introduction of a New Hydrocarbon Based Chemical for Wettability Alteration of Reservoir Rocks to Gas Wetting Condition

Abstract

Summary Condensate and water blockage are known as the most prevalent causes of well productivity decline in gas condensate reservoirs. The methodology of wettability alteration of near wellbore region to gas wetting condition, is a novel and permanent technique to address the aforementioned problem. In this work, we report the introduction of a hydrocarbon based polymer solution to change the wettability of reservoir rocks from liquid wetting to intermediate- to gas wetting condition. Both air-n-decane and air-water contact angles changed from liquid wetting condition to intermediate and gas wetting condition, respectively, after treatment of calcite and laminated glass thin sections with chemical solution. The results of air-liquid spontaneous imbibition tests showed remarkable decrease in the amount of imbibed liquid, which confirms the decrease of rock affinity to liquid phase as a result of chemical treatment. The core flooding experimental results demonstrate significant improvement of liquid phase mobility as a result of wettability alteration. Effectiveness of the proposed chemical solution to alter the wettability of both sandstone and carbonate rocks from strongly liquid wetting to preferentially gas wetting condition, along with its economic price and environmental friendly characteristics, makes it an attractive choice for future field applications in gas condensate reservoirs.