Synthesis and Application of a New Polymeric Surfactant for Improving Oil Recovery: Interfacial Tension, Wettability and Viscosity Studies in Different Salinities

Abstract

Abstract With the decline of conventional hydrocarbon reserves, polymers are widely used in various enhanced oil recovery (EOR) methods like surfactant-polymer (SP) flooding and alkaline-surfactant-polymer (ASP) flooding. The SP flooding method has a very complex formulation and design, and due to improper mixing, there may be undesirable phase separation. Recently, interesting work has been reported on synthesizing polymeric surfactants for use in EOR. Polymeric surfactants, as new compounds, are an attractive alternative to SP flooding because polymeric surfactants in which hydrophobic groups are attached to hydrophilic polymers play a dual role in improving the mobility ratio and reducing interfacial tension (IFT). The present paper deals with the rheological and synthesis properties of a new polymeric surfactant produced by bond co-polymerization reaction using different ratios of hydrolyzed polyacrylamide (HPAM) and a zwitterion hydrophobic group. Synthesized Hydrophobically Modified Zwitterionic Polyacrylamide (HMZPAM) was characterized by FTIR and HMNR analysis. The performance of polyacrylamide and HMZPAM were compared and the results show that HMZPAM was more and more suitable for EOR. HMZPAM was much better in IFT, Viscosity, Wettability, Oil recovery, and resistance to the different one and two valence cations. Our results show that while HPAM reduced the IFT to 13.65, HMZPAM reduced the IFT to 0.441 mN/m. The contact angle of the oil-wet rock sample changed to 62.76 (water-wet) and 21.23 degrees (strongly water-wet) using HPAM and HMZPAM, respectively. In salinity of 10,000 mg/l, the viscosity of HPAM and HMZPAM were measured as 62 cp and 174 cp, and at the shear rate of 400 S− 1, the viscosity of HPAM and HMZPAM was equal to 0.14 cp and 1.06 cp, respectively. HMZPAM also showed better properties in elevated salt concentrations. Core flooding tests showed that HMZPAM yields have better additional recovery due to the microscopic displacement than HPAM, with a total oil recovery of 84% compared to 48%.