An experimental investigation on enhancing water flooding performance using oil-in-water emulsions in an Iranian oil reservoir

Emulsions are extensively prevalent in the oil industry in both advantageous and disadvantageous ways. In the literature, conventional water flooding in high permeability oil reservoirs has confronted with water channeling and poor sweep efficiency. In this paper, the remedial application of O/W emulsions as an EOR method in improving water performance is discussed. To this purpose, a series of flooding experiments were carried out in one of the Iranian oil reservoirs in reservoir condition of 75 C and 2000 psi. Then, visual stability measurements were conducted to inspect the stability characterization of the emulsion. Sodium dodecyl sulfate was applied helping simple dispersion of the gasoil into the water phase, and emulsions with water percentage of 90, 80, 70 and 60 were developed to introduce into the porous media. It was found out from flooding experiments that emulsion injection after conventional water flooding can lead to additional oil recovery (up to 20%). Besides, the emulsion with 80% water cut was determined as the optimum emulsion for injection in this reservoir considering financial aspects. Moreover, results of the stability test revealed that the aqueous phase with one wt% surfactant or higher had formed emulsions which have been stable during a long period of 6 months.