ASSESSMENT OF ENHANCED OIL RECOVERY TECHNIQUES FOR OFFSHORE RESERVOIRS

ABSTRACT This research project presents a comprehensive evaluation of Enhanced Oil Recovery (EOR) techniques, focusing on the comparative effectiveness of water flooding, Alkaline-Surfactant-Polymer (ASP) flooding, thermal flooding using hot water injection, and a hybrid approach combining thermal and chemical methods. The study aims to determine the optimal EOR strategy for maximizing oil recovery across a range of crude oil viscosities, providing insights into their application under different reservoir conditions. Experimental investigations were conducted using a transparent core holder system packed with porous media. Five crude oil samples, ranging from low to high viscosities (5 cp to 150 cp), were used to establish the effect of oil properties on recovery efficiency. Baseline oil recovery was first established through water flooding. Subsequent experiments involved the injection of ASP slugs, hot water, and a combination of hot water and ASP slugs to evaluate the incremental oil recovery potential of each method. Key performance indicators, including Initial Oil in Place (IOIP), recovery by water, recovery by EOR methods, total oil recovery, and irreducible oil saturation, were systematically measured and analyzed. The results indicate that water flooding effectively mobilizes oil at lower viscosities but becomes inefficient as viscosity increases. ASP flooding significantly enhances oil recovery for medium-viscosity oils by reducing interfacial tension and improving sweep efficiency. Thermal flooding was most effective for high-viscosity oils, facilitating reduced oil viscosity and improved flow dynamics. The hybrid method, combining thermal and chemical mechanisms, exhibited the highest recovery efficiency across all viscosity ranges, achieving up to 30% additional recovery beyond water flooding. The study concludes that a strategic selection of EOR methods tailored to specific oil properties and reservoir conditions is crucial for optimizing oil recovery. The hybrid approach demonstrates substantial potential for complex reservoirs where conventional methods are less effective. Recommendations for future work include field-scale validation of laboratory findings and further investigation into the synergistic effects of hybrid EOR techniques to enhance overall recovery performance.