Application of Fatty Acid Methyl Ester from Biomass for CO2-Crude Oil MMP Reduction

Carbon dioxide (CO₂) flooding is a widely adopted enhanced oil recovery (EOR) technique known for its ability to displace crude oil effectively by altering its properties. However, in high-temperature Malaysian reservoirs, achieving the minimum miscibility pressure (MMP) for successful miscible flooding can be challenging. This study investigates the potential of using fatty acid methyl esters (FAMEs) derived from biomass sources to lower the MMP in CO₂-crude oil systems, thereby enhancing CO₂-EOR performance. FAME, renewable and sustainable, presents an innovative alternative to conventional petroleum-based chemicals in EOR. The study involved two types of biomass-derived FAME, sourced from Rubber Seed Oil and Palm Kernel Oil, and two types of crude oil, Tapis and Dulang, tested using the slim tube method at 90 °C and pressures up to 4500 psi. Our findings indicate the presence of Methyl Oleate in Rubber Seed Oil and Methyl Laurate in Palm Kernel Oil, both likely derivatives formed during biodiesel production through transesterification. The MMP for Tapis crude oil was 3620 psi, and for Dulang crude oil, it was 3860 psi, exceeding both the reservoir and fracture pressures of the formation. This can lead to inefficient CO₂ injection, reservoir fracturing, and increased costs. However, the addition of 5% vol. FAME to Tapis crude oil demonstrated promise, with Methyl Laurate reducing the MMP by 17.12% and Methyl Oleate by 3.34%. Increasing the concentration of Methyl Laurate to 10% vol. resulted in a substantial 21% MMP reduction. Notably, the presence of waxes and asphaltenes further lowered the MMP compared to pure Tapis crude oil, with Methyl Laurate achieving a 6.42% reduction compared to 17% for Methyl Oleate. In conclusion, this study explores the use of biomass-derived FAME to improve CO₂ flooding performance by lowering MMP. The findings suggest that FAME, particularly Methyl Laurate, offers a sustainable solution to address MMP challenges in CO₂-based EOR operations, contributing to the advancement of the oil industry in the region.