Sophorolipids-based Biosurfactant Application for the Flow Assurance Problems in the Petroleum Industries: An Experimental Approach

Abstract Flow assurance is a significant issue for the transport of heavy crude oils as these oils tend to have high viscosity, wax crystallization and related changes that can result in higher pressure and flow resistance. Biosurfactants present a promising alternative for enhancing the flowability of crude-oil in a sustainable manner. The present study experimentally aims to characterize the application of the biosurfactant Sophorolipids produced by the Candida bombicola for the improvement of flow properties for two heavy crude oils (LANWA and JOTANA). Sophorolipids was evaluated at concentrations of 0, 1000, 3000, 5000, and 7000 ppm. Pour point tests were conducted as per ASTM D97, and subsequent tests were conducted on rheological behavior using a shear rate of 1-100 s-1 and temperature range of 70 to 30°C in Anton Paar MCR 302e rheometer. The hydraulic resistance was also studied after the treatment in a 5 m experimental flow loop at 5 mL/min. The flowability of both crude oils increased as a function of the concentration of Sophorolipid treatment. The pour point of LANWA and JOTANA decreased by 28.4 and 26.3, respectively, from 28.4 °C to 20.2 °C and 26.3 °C to 19.8 °C, respectively at 7000 ppm. The two crude oils exhibited shear-thinning characteristics, as determined by the rheological measurements; significant viscosity reductions were observed at higher concentrations of sophorolipids. The maximum reduction in viscosity reported was about 75% for LANWA and 92-90% for JOTANA. These flow-loop measurements also showed a decrease in differential pressure of ΔP = 13.3% for LANWA and 32.9% for JOTANA at 7000 ppm. Sophorolipids improved heavy crude-oil flowability while reducing viscosity and pressure losses at low temperatures. Their effectiveness varied between LANWA and JOTANA oils, indicating a strong dependence on crude-oil composition. Overall, sophorolipids show potential as biodegradable flow-assurance additives, pending further large-scale field validation.