Condensate blockage phenomenon in near-wellbore region decreases gas production rate remarkably. Wettability alteration using fluorinated chemicals is an efficacious way to mitigate this problem. In this study, we investigate the effect of fluorinated surfactants and ZnO zinc oxide nanoparticles separately and simultaneously on the change of wettability of carbonate rocks and sandstone rocks of gas condensate reservoirs from liquid-wetting (oil-wet or water wet) to liquid-repellent in such a way that after treating the reservoir rock with the fluorinated chemicals, it causes an increase in the extraction of condensate from the condensate gas reservoirs. In this study, the effect of chemical treatment and roughness factors on the change of wettability from liquid-wetting to liquid-repellent has been investigated. For this purpose, firstly, the carbonate and sandstone samples obtained from the southern reservoirs of the country were cut to appropriate dimensions and (AFM XRD (tests were performed to determine the type of rock. Then it has been polished with polish paper to numbers 400, 800, 1200. In order to better and more accurately examine the effect of the roughness of the samples in the range of 5 micrometers and 50 nm, they were also polished with alumina oxide and nano alumina oxide. Then, AFM tests were performed to check the surface roughness before and after polishing the sample. In order to chemically treat stone, there is a need for a cheap and environmentally friendly surfactant, water-based suspensions have been prepared with different concentrations of surfactant (1, 3 and 5%) and also the effect of different concentrations of salt (5000, 10000 and 20000 PPM) has been investigated for chemical treatment. In order to check the effect of the treatment done in the optimal concentration of surfactant (5%), the contact angle and spontaneous imbibition tests have been done before and after the chemical treatment. The results show that the effect of the used surfactant is quite evident and the contact angle of water and normal decan fluids has increased from about 26 and 20 degrees to 141 and 130 degrees in the best case. Also, in order to investigate the effect of roughness on the wettability of ZnO nanoparticles in 2 different morphologies (spherical and flower-shaped), it has been synthesized by sol-gel method. In order to check the morphology of nanoparticles(FE-SEM( tests were performed on the samples. Then, 0.1% by weight was added to the fluid and its effect on wettability was eva‎luated by contact angle and spontaneous absorption tests. The results show that by adding nanoparticles due to roughness, the amount of contact angle and spontaneous imbibition has improved by about 9%. And the results of investigating the effect of the morphology of nanoparticles show that nanoparticles with a flower-shaped morphology have a better performance in changing wettability due to having a higher surface-to-volume ratio compared to spherical nanoparticles, and the results of the contact angle and spontaneous absorption tests are 3%. has improved.

روح اله هاشمي

روح اله هاشمي , علي اكبر دادخواه