Enhanced Oil Recovery (EOR) Techniques in Mature Reservoirs

Abstract

As global energy demands rise, the need for efficient hydrocarbon extraction from mature reservoirs has become increasingly critical. Enhanced Oil Recovery (EOR) techniques offer viable solutions to extend the productive life of depleted reservoirs by improving oil displacement and sweep efficiency. This study evaluates the efficiency, economic feasibility, and environmental impact of advanced EOR methods, including chemical flooding, gas injection (particularly CO₂-EOR), thermal recovery, and microbial EOR. A comprehensive analysis of case studies, numerical simulations, and laboratory experiments was conducted to assess these techniques in three mature reservoirs with varying geological conditions.

The findings highlight that thermal EOR (steam injection) demonstrated the highest recovery rates, particularly in high-temperature reservoirs, while CO₂ injection was effective in maintaining reservoir pressure and improving oil displacement. Chemical flooding showed moderate success, whereas microbial EOR had limited applicability. The study underscores the importance of tailoring EOR strategies to reservoir-specific characteristics and balancing economic and environmental considerations. Future research should focus on hybrid EOR approaches, digital reservoir modelling, and sustainable energy-driven recovery systems to optimise oil recovery while minimising environmental impact.