Investigation of the Effect of Sulfate Sediment Particles on Water-Oil Emulsion Formation when Mixing Smart Water-Formation Water

Precipitate migration during smart water injection plays a significant role in improving the oil recovery. This study showed that the process of mixing two incompatible water causes sulfate precipitate production while introducing oil to the combination results in an emulsion formation. The main objective of this study is to investigate the fine solids present in the water and their roles in emulsion formation and how they affect the oil recovery. Three types of formation water were used in this study. These 3 water types contained high concentrations of barium, calcium and strontium ions respectively. The smart water contains high concentration of sulfates. Moreover, crude oil and model oils (containing Stearic acid) were used in order to study the emulsion formation conditions. The composition of both primary oil and floating oil were studied using UV analyzing method. Finally, the effect of emulsion formation in porous media on oil recovery was studied. Experiments showed that mixing smart and formation water results in Barium, calcium and Strontium Sulfate precipitation. By introducing oil to the combination of the two water types, a reduction in the amount of precipitate was observed. Finally, the results, which were obtained by implementing UV, showed that amount of stearic acid and also the precipitates were decreased in the oil phase. Therefore, this must be due to the interaction among polar components of the oil phase and the precipitate fines, which it causes an emulsion formation. Water flooding using a smart water containing sulfate ion, and the one that does not contain sulfate, have shown that precipitates which have caused an emulsion formation increases the recovery factor from 14 to 47 percent.