Gas-condensate production improvement using wettability alteration: A giant gas condensate field case study

Productivity loss due to condensate blockage is the main and common problem in gas condensate reservoirs around the world. Several methods such as gas recycling, hydraulic fracturing and solvent injection have been proposed to overcome this problem. But these methods usually are effective just for short periods of time. A novel approach in gas condensate reservoirs is altering the wettability of the reservoir rocks from strongly liquid wetness to preferential gas wetness or intermediate-wetting by treating them with chemicals. Most of experimental studies have focused on finding chemicals to perform a permanent wettability alteration in lab scale, but the effect of wettability alteration on production improvement in field scale has not been studied well enough, yet. s paper, the effect of wettability alteration on gas-condensate production improvement in field application was studied. First a radial single compositional well model was constructed using fluid and reservoir data from a giant gas condensate field in the Middle East located in the south of Iran. Three different relative permeability curves have been used in the model which represent three different wettability states. sults showed that field gas-condensate cumulative production was improved greatly after the wettability of porous media was altered from liquid-wetting to intermediate- or gas-wetting by changing relative permeabilities for a treatment radius of 5 m around the wellbore. Production improvement in the intermediate-wetting state was maximized. Also, wettability alteration results in decreasing condensate saturation around the well and increasing the well bottomhole flowing pressure and productivity index.