Application of Palm Oil Mill Effluent and Palm Bunch as Emulsion Chemicals in Oil Reservoir Flooding Operation

Abstract Oil reservoir flooding is a widely employed method to enhance oil recovery from depleted fields. However, conventional flooding techniques often encounter challenges related to environmental concerns and cost-effectiveness. In recent years, there has been growing interest in utilizing sustainable and eco-friendly materials for enhanced oil recovery processes This research focused on the potential utilization of two abundant agro-waste by-products from the palm oil mill industry, namely palm oil mill effluent (POME) and ash derived from burnt empty palm fruit bunches (EPFB). Oil/grease/water was extracted from palm oil mill effluent using a centrifuge; surfactant solution was prepared with ash from burnt empty fruit bunch and distilled water. Oil/surfactant emulsions were formulated using different ratios of oil/surfactant ratio (10/90, 20/80, 30/70, 40/60, 50/50, 60/40, 70/30, 80/20 and 90/10). The formulated emulsion was analyzed to evaluate its stability and compatibility with reservoir formation water. Nine Core samples of 10cm x 8cm x 6cm dimensions were initialized at reservoir conditions by flooding them with brine of salinity of 15000ppm until the differential pressure became stabilized. The brine was produced till pressure stabilized, and the original oil in place was determined by flooding the brine-saturated core samples with crude oil (32.9 API). Then the crude oil-saturated core samples were firstly flooded with water till oil production ceased, and oil production volume was observed. Secondly, to produce the residual oil in the previously water-flooded core samples, the core samples were respectively flooded with the formulated emulsions of different oil/surfactant solution ratios. The results revealed that water flooding yielded 32.5% of the oil in the respective core samples while different ratios of formulated emulsion (10/90, 20/80, 30/70, 40/60, 50/50, 60/40, 70/30, 80/20 and 90/10) yielded incremental oil recovery of 31.3%, 30.5%, 30.9%, 29.3%, 29.1%, 30.6%, 30.7%, 31.0%, 31.2% respectively. These brought the total oil recovery for both water flooding and formulated emulsions operation from the core nine core samples to 70.5%, 69.4%, 68.8%, 68.7%, 69.1%, 69.5%, 69.9%, and 70.2%, respectively. The experiments suggest that certain emulsion compositions enhance the mobilization and displacement of oil, leading to better reservoir sweep efficiency. It was found that certain ratios of oil-in-surfactant solution, and surfactant solution-in-oil emulsions yield higher recoveries.