Abstract
Crude oil with a high wax content and high pour point can be very challenging when enhanced oil recovery by surfactant flooding is to be applied. High wax content in crude oil will lead to high intermolecular interaction because of the increasing cohesion forces. It causes interfacial (IFT) tension between oil and brine to be high. Hence, oil recovery is relatively low. This paper presents formulation of an amphoteric sulfonate alkyl ester (SAE) surfactant with a nonionic surfactant (ester group) to reduce oil–brine IFT in waxy oil of T-KS field, in Indonesia. The ion–dipole forces may occur between SAE surfactant and nonionic cosurfactant molecules. The forces cause sulfonate chain to be attracted to oil phase. The formulated surfactant produces low interfacial tension between brine and waxy oil of T-KS oil field. Its ability to displace remaining oil in the pore space was also tested using coreflood tests. These tests demonstrate considerably good incremental recovery.
Highlights
The research of surfactant for enhanced oil recovery has been continuously developing
From the LCMS measurement, the sulfonate alkyl ester (SAE) surfactant appears in chromatogram at retention time 3.6 min and the mass spectrum showed that the SAE surfactant has molecular weight (MW) higher than 500 g/mol
Griffin (1949, 1954) classified surfactants based on hydrophilic–lipophilic balance (HLB) and proposed a formula to compute HLB of ionic and nonionic surfactants
Summary
The research of surfactant for enhanced oil recovery has been continuously developing. It has been long known surfactant ability to lower interfacial tension of oil–brine. It reduces capillary forces of oil–brine in the pores which results in increasing displacement efficiency and lowering residual oil saturation. A theoretical model was introduced by Huh (1979) to predict oil–water interfacial tension as a function of corresponding solubilization ratio of oil and water in the microemulsion-phase (middle-phase). As solubilization ratio of oil and water for specific surfactant is affected by water salinity, Salager et al (1979) showed that optimum salinity can be established as a function of surfactant structure, alkane carbon number (ACN), and alcohol type, concentration, and temperature. In 2017, Torrealba and Johns presented a model that predicts interfacial tension and phase behavior for all Winsor types and overall compositions
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
