Effect of Alcohol Addition on Phase Behavior and Interfacial Tension of MES Surfactants
Rambun Pamenan Khaifi (a*), Rini Setiati (b), Listiana Satiawati (a), Asri Nugrahanti (a), Muhammad Taufiq Fathaddin (b), Dwi Atty Mardiana (c)

a) Departement of Petroleum Engineering, Universitas Trisakti, Jakarta, Indonesia
b) Master Program of Petroleum Engineering, Universitas Trisakti, Jakarta, Indonesia
c) Environment, Development, and Sustainability - Faculty of Graduate School, Chulalongkorn University, Thailand

Abstract

Oil wells in Indonesia are facing a steady decline in production due to their advanced age. To restore optimal oil production rates, Enhanced Oil Recovery (EOR) methods using surfactant injection have been chosen. This study investigates the effectiveness of using Methyl Ester Sulfonate (MES) derived from palm oil as a surfactant, with the addition of 96% ethanol as an additive. The goal of surfactant injection is to reduce the Interfacial Tension (IFT) between water and oil, thereby lowering capillary pressure in the reservoir rock^s narrow pores. Laboratory experiments were conducted using different concentrations of MES surfactant (0.5%, 0.75%, 1%, 1.25%, 1.5%, 1.75%, and 2%) with 96% ethanol as an additive in brine with a salinity of 7,500 ppm at 60C. Initial tests revealed the surfactant solution was unstable, prompting the addition of a co-surfactant. Each concentration of surfactant and co-surfactant was then mixed with light oil (33API) in pipette tubes. Stability tests showed that the surfactant and co-surfactant solution was stable. The best middle phase emulsion was achieved at a concentration of 1.25% with a salinity of 7,500 ppm, forming 0.06 ml or 1.5% of emulsion. At this concentration, the surfactant also exhibited the lowest IFT value of 0.457 dyne/cm.

Keywords: EOR- Surfactant- MES- Cosurfactant- IFT

Topic: Reservoir engineering