Original oil in place is critical for maximizing hydrocarbon production from mature reservoirs. Polymer flooding is a widely applied chemical EOR technique designed to improve sweep efficiency by increasing the viscosity of injected water, thereby achieving a more favourable mobility ratio. This thesis presents a comprehensive numerical simulation study to eva‎luate the effectiveness of various polymer injection strategies in a synthetic, two-dimensional heterogeneous carbonate reservoir model. The primary objective was to quantify the impact of key operational parameters on oil recovery. Using Schlumbergerʹs PETREL™ an‎d ECLIPSE™ software, ten distinct scenarios were simulated to assess the sensitivity of performance to polymer concentration (2000 ppm vs. 3000 ppm), water salinity (low, medium, high), polymer adsorption, an‎d injection strategy (edge vs. central, slug vs. continuous). The performance of these EOR scenarios was rigorously compared against a baseline waterflooding case over a 20-year production period. The simulation results yielded a clear an‎d unexpected primary finding: the baseline waterflooding (Scenario 1) was the most effective recovery method, achieving an oil recovery factor of 86.96%. Critically, all ten polymer injection scenarios resulted in lower final oil recoveries, with recovery factors ranging from a high of 83.04% to a low of 71.65%. The analysis identified polymer adsorption an‎d high polymer concentration (3000 ppm) as the most detrimental factors, causing significant reductions in recovery. Salinity variations, within the tested range for cases without explicit adsorption, showed a surprisingly negligible impact on the final recovery. The principal conclusion of this study is that for the specific reservoir model an‎d parameters investigated, polymer flooding was not a viable EOR technique, an‎d, in fact, impaired production compared to conventional waterflooding. These findings highlight that the theoretical benefits of polymer injection can be completely negated by detrimental mechanisms like polymer retention an‎d injectivity issues. This work underscores the paramount importance of reservoir-specific laboratory testing an‎d calibrated simulation studies to mitigate risks an‎d validate EOR potential before field implementation, cautioning against the generic application of polymer flooding without a thorough understan‎ding of the unique rock-fluid system.

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محسن محمدي , روح اله هاشمي