Today, due to the increasing need for oil resources, for use in various industries, the need to oil recovery resources is felt more than in the past, but due to the reduction in the capacity of oil resources an‎d the reduction in oil resource exploration, primary an‎d secondary oil recovery methods cannot be responsible for supplying oil forever. Therefore, there is a need to use methods to enhanced oil recovery, one of the most important of which is chemical enhanced oil recovery. The two main mechanisms in chemical enhanced oil recovery include changing wettability an‎d reducing interfacial tension. Various materials such as surfactants, alkalis an‎d nanoparticles are used to change wettability an‎d reduce interfacial tension in chemical enhanced oil recovery. One of the best of these materials is surfactants. However, various factors such as brine concentration an‎d high temperature affect the performance of surfactants an‎d other materials, so research is always underway to find a more suitable material in this field.In the present study, based on the reviewed studies, polydopamine, which has been used in many fields to hydro‎philicize various surfaces, especially the surface of hydro‎phobic membranes, was used to hydro‎philicize the surface of oil-wet carbonate slabs. To compare the effect of this material compared to conventional materials, according to the case studies, the cationic surfactant CTAB an‎d the anionic surfactant SDS were used at optimal concentrations of CTAB (50, 100, 360 ppm) an‎d the SDS surfactant at (0.2, 0.25, 0.3 w/w%) concentrations. In the first stage, the change in wettability of the oil-wet carbonate slab at ambient temperature was investigated alongside the surfactants, then the effect of polydopamine on the change in wettability of the oil-wet carbonate slab at the optimal concentration an‎d other concentrations at different times was investigated. In the next stage, the effect of polydopamine on the change in wettability of the slabs aged with surfactant was investigated. an‎d in the last stage, the effect of polydopamine an‎d polydopamine solution without buffer on the reduction of water-oil interfacial tension was investigated. The results showed It shows that cationic surfactants CTAB had a greater effect on the change in wettability of carbonate slabs than SDS surfactant. Also, polydopamine did not have a significant effect on the change in wettability of oil-wet carbonate rock. At its optimal concentration of 2 mg/ml, it reduced the contact angle of oil-wet carbonate slabs from 131.3 to 125.8 within 5 hours an‎d from 135.8 to 131.2 within 72 hours, an‎d the contact angle was unchanged at 24 an‎d 48 hours. But in the final stage, it had a good effect on the change in wettability of the surface of the oil-wet carbonate rock aged with surfactants. Polydopamine was able to reduce the contact angle of oil-wet carbonate slabs aged an‎d partially hydro‎philic with surfactants (CTAB 100, 50 ppm) an‎d SDS 0.25% from 43.5 to 29.56, from 60.5 to 32.6, an‎d from 82.9 to 42.25, respectively. an‎d polydopamine had a better effect on the slab aged with SDS surfactant than the slab aged with CTAB. But dopamine without buffer had little effect on the change in wettability of the carbonate slab aged with SDS 0.2% surfactant an‎d its contact angle only decreased from 82.9 to 76.05. The use of polydopamine also showed that polydopamine could have a favorable effect on reducing the water-oil interfacial tension from 15.76 mN/m to 5.31 mN/m for a (3 mg/ml) polydopamine-oil solution.

محسن محمدي , سهيل ضرغامي

روح اله هاشمي , صفورا كريمي