A Systematic Study to Assess Displacement Performance of a Naturally-Derived Surfactant in Flow Porous Systems

Abstract

For the first time, the present work assesses the feasibility of using Korean red ginseng root extract, a non-ionic surfactant, for the purposes of enhanced oil recovery (EOR). The surfactant is characterized by Fourier-transform infrared spectroscopy (FT-IR) analysis. Pendant drop and sessile drop techniques are employed to study the oil–water interfacial tension (IFT) and wettability nature of the sandstone rock, respectively. In addition, oil recovery enhancement is investigated using micromodel and core floods. In the salt-free system, IFT measurements indicate that the surfactant carries a critical micelle concentration of 5 g/L. In a saline medium (up to 50 g/L), the addition of a surfactant with different concentrations leads to an IFT reduction of 47.28–84.21%. In a constant surfactant concentration, a contact angle reduction is observed in the range of 5.61–9.30°, depending on salinity rate, revealing a wettability alteration toward more water-wet. Surfactant flooding in the glass micromodel provides a more uniform sweeping, which leads to an oil recovery enhancement of 3.02–11.19%, depending on the extent of salinity. An optimal salt concentration equal to 30 g/L can be recognized according to the results of previous tests. Surfactant flooding (10 g/L) in optimal salt concentration achieves an additional oil recovery of 7.52% after conventional water flooding.

Keywords

• non-ionic surfactant
• interfacial tension
• wettability
• micromodel and core flooding
• salinity