The Effect of AOS Surfactant Injection on Increasing Oil in Laboratory Study

The decline in oil production is currently a big challenge. To overcome this problem, the Enhanced Oil Recovery (EOR) method was used. The EOR method used is surfactants, such as AOS Surfactant (alpha-olefin sulfonate). This laboratory research used five AOS concentrations (0.3; 0.5; 0.75; 0.9; 1%), with a salinity of 7,000 ppm. AOS was chosen because of its ability to reduce interfacial tension. The research carried out was a phase behavior test to assess the stability of the emulsion for 14 days at a temperature of 80C. The process of making a surfactant solution involves mixing AOS powder with brine with an acidity of 7,000 ppm. The experimental phase includes testing density, water stability, phase behavior, interfacial tension, and core flooding. First, the density test was carried out with a DMA-4100 densitometer at temperatures of 30 and 80 °C. Second, Aqueous Stability was evaluated to determine the stability of the surfactant solution. The third stage involved a phase behavior test, where the mixture of surfactant and oil solutions was heated at 80°C for 14 days to ensure a stable emulsion was achieved. Interfacial tension analysis was carried out to assess the ability of AOS surfactant to reduce interfacial tension, showing good results with a value of 0.821309 dyne/cm between oil and formation water in the reservoir. Finally, a core flooding test was carried out to determine the oil recovery factor from sandstone, with the results of a recovery factor of 7.2727% for AOS surfactant with a concentration of 1% at a salinity of 7,000 ppm.