Surfactant mixture in partially hydrolyzed polyacrylamide polymer for enhanced oil recovery

Abstract

Chemical EOR has won significant interest in the oil and gas industry over decades. The use of nanoparticles, alkaline, foam and most importantly polymers and surfactants, have been widely explored. Surfactants have achieved great interest because it can reduce IFT and subsequently improve oil recovery. Polymers on the other hand have gained significant importance due to their ability to increase the viscosity of the injected fluid by rendering oil at the oil-water interface less viscous than water and increasing its mobility, yielding a higher oil recovery. In this work, the surface tensions of AOS and SDS were investigated using a ring experiment method at different salinities, followed by their respective IFTs until the critical micelle concentrations were observed. The SDS and AOS were then mixed at a ratio of 1:1 and the IFT measured accordingly. A blend of AOS, SDS and HPAM was made and the IFT measurement was repeated. The viscosity of the HPAM was made, followed by the displacement test in a sand pack flooding setup and the results recorded. The IFT values of 6.6 mN/m for SDS at 0.1% wt, 7.7 mN/m for AOS at 0.1 %vol. were achieved. Nonetheless, a blend of AOS, SDS and HPAM, gave an IFT at CMC of 8.5 mN/m at 1000ppm of polymer while viscosity proved contrary that the solution with 2000 ppm was the most stable. Finally, 73% of oil was recovered using water flooding, 78% was further obtained using HPAM and finally 83% using SDS, AOS and HPAM in a hybrid system. This therefore concludes that the combination of HPAM and a blend of SDS and AOS, can impact meaningfully to EOR applications.