Liquid Repellency in Gas Condensate Reservoirs Using Different Chemical Treating Agents

Liquid blockage decreases gas condensate productivity when the reservoir pressure near the wellbore falls below the dew point. Wettability alteration is the most promising method among various techniques to overcome the liquid blockage. In this study, the ability of different chemical solutions to change the wettability of rock types; carbonate and synthetic rocks from liquid-wet to a gas-wetting state was investigated. Contact angle measurement was conducted to evaluate the effect of the treating process. It was found that some of the best solutions containing COUPSYL®WRS nanofluid, PTFE, hydrophobic SiO2 nanoparticles + PDMS, could change the water contact angle from 0° to 130.5°, 142.7°, and 155°, respectively. They could also produce water repellency conditions. In contrast, they were not effective on the synthetic rock surface. Moreover, the contact angle of condensate did not change by using these chemicals and remained at 0°. It was also shown that by increasing SiO2 nanoparticle concentration from 0 to 2 wt%, the water contact angle increased from 117° to 155°, which was the most effective chemical solution in the wettability alteration process.