Influence of whey protein isolate on CO2 foams stability in three different types of crude oil

Abstract

The foam performance in the presence of oil plays an essential role in foam application in enhancing oil recovery. This study systematically investigated whey protein isolate (WPI), the effectiveness of foam generation, the effect of three types of crude oil, surfactant concentration on foam performance and oil-water interfacial tension (IFT). The extraction of WPI was compared to sodium dodecyl sulfate (SDS) at the microscopic foam images to have a better understand of foaming in terms of performance. The results showed that the WPI lowers the surface tension, which also tends to disclose and stabilize the interface by forming a viscoelastic network. SDS reduced the surface tension compared to the WPI but did not produce a high modulus interface. WPI generated a more stable foam in oil than SDS foam. The WPI improved foam stability by increasing the gas-water interface dilatational viscoelasticity layers. WPI solution decreases bubble sizes and prevents oil from spreading at the foam lamellae. The WPI foam exhibits higher stability in Libya crude oil when the oil saturation is between 0–20%. WPI foam reduces fluid loss and hinders the movement of oil droplets within the lamella, the significant viscosity contrast between oil and WPI-CO2. Waxy oil is detrimental to both SDS and WPI foam, while waxy oil can harm WPI foam in some specific cases. The oil-water IFT was reduced to extremely low levels by WPI. As a result, WPI's interfacial tension values with Sharara oil were (21 mN/m) and SDS's were (44.5 mN/m).