Semnan University Press Applied Chemistry Today 2981-2437 12 43 2017 06 22 -Experimental Investigation of the Impact of Smart Water and Surfactant Solution on Enhanced Oil Recovery in Carbonate Reservoirs -Experimental Investigation of the Impact of Smart Water and Surfactant Solution on Enhanced Oil Recovery in Carbonate Reservoirs 9 22 2358 10.22075/chem.2017.2358 FA Saeb Ahmadi Amir Hossein Saeedi Dehaghani Mohammad Mahdi Shadman Journal Article 2016 02 27     A considerable quantity of the world’s oil reserve is located in naturally fractured carbonate reservoirs, with very low oil recovery efficiency, due to their wettability abd tightness of matrix. Recovery efficiency can be improved considerably, if the reservoir rock wettability is changed from mostly oil-wet to water-wet, thus enhancing water imbibition into the oil saturated rock. Smart water is able to alter the carbonate rock wetability from oil-wet to intermediate to water-wet, and therefor, water imbibition into the rock matrix is facilitated. In this study, the effect of ions and different surfactants concentration in the smart water on  the wettability state of carbonate rocks was investigated by contact angle measurements and spontaneous imbibition experiments. Imbibition experiments were performed at three temperature level(50, 70 and 90 C). The effect of ions, temperature, and surfactant concentration on the wettability alteration of carbonate rocks during spontaneous imbibition process were invistegated. The results showed that the presence of SO42- ions, the strongly affects the wetting state of carbonate rocks, and  increasing SO42- concentration from 0.033 mol/l to 0.1 mol/l increased the oil recovery from 19% to 58%. Moreover, by increasing Mg2+ concentration the oil recovery increases (from 19% to 23%). Also  the presense of cationic surfactant C12TAB, strongly changed the wetting state of carbonate rocks, and also increased  the oil recovery from 19% to 78%.     A considerable quantity of the world’s oil reserve is located in naturally fractured carbonate reservoirs, with very low oil recovery efficiency, due to their wettability abd tightness of matrix. Recovery efficiency can be improved considerably, if the reservoir rock wettability is changed from mostly oil-wet to water-wet, thus enhancing water imbibition into the oil saturated rock. Smart water is able to alter the carbonate rock wetability from oil-wet to intermediate to water-wet, and therefor, water imbibition into the rock matrix is facilitated. In this study, the effect of ions and different surfactants concentration in the smart water on  the wettability state of carbonate rocks was investigated by contact angle measurements and spontaneous imbibition experiments. Imbibition experiments were performed at three temperature level(50, 70 and 90 C). The effect of ions, temperature, and surfactant concentration on the wettability alteration of carbonate rocks during spontaneous imbibition process were invistegated. The results showed that the presence of SO42- ions, the strongly affects the wetting state of carbonate rocks, and  increasing SO42- concentration from 0.033 mol/l to 0.1 mol/l increased the oil recovery from 19% to 58%. Moreover, by increasing Mg2+ concentration the oil recovery increases (from 19% to 23%). Also  the presense of cationic surfactant C12TAB, strongly changed the wetting state of carbonate rocks, and also increased  the oil recovery from 19% to 78%. https://chemistry.semnan.ac.ir/article_2358_850df71ecb321335764b36c94d481a7e.pdf