Asphaltene Stability and Wettability Alteration During Smart Water Flooding

Invasion of external fluids into the reservoir during different operations could cause formationdamage in the form of asphaltene deposition, which consequently, reduces the oil recovery of therecoverable reserve. Removing and preventing the asphaltene deposition is a very challenging task. Theobjective of the present study is to experimentally investigate the wettability alteration duringsurfactant-smart water flooding and its potential to mitigate asphaltene deposition damage in originaloil-wet reservoirs. In this regard, contact angle experiments on carbonate surface treated with differentsolutions showed contact angles lower than ۹۰°. Thus, wettability alteration from oil wetting to morefavorable water wet states was achieved. The highest wettability alteration index of ۰.۹ was obtainedwhen surfactant in a brine solution containing ۹.۶۱ g/l sulfate ion has been used, which revealed thatlarge amounts of carboxylate acid adsorbed on the carbonate surface, were removed. The modifiedsurface reduced the hydrophobicity of the surface and promoted the oil production from the reservoir.