Perpustakaan Digital ITB

Chemical Enhanced Oil Recovery (CEOR), particularly polymer and surfactant-polymer (SP) flooding, offers potential for improving oil recovery from mature Indonesian fields. This study numerically evaluated laboratory polymer and SP coreflood experiments from Field “M” using CMG STARS to assess their recovery performance and underlying displacement mechanisms. The waterflood stages were historymatched using Corey-type relative permeability curves, while the chemical-injection responses were evaluated against laboratory data through capillary-desaturation, viscoelastic, and parameter-sensitivity analyses. Both waterflood stages were reproduced with deviations of approximately 1%. For the polymer coreflood, the simulation using measured polymer properties produced a recovery factor of 71.56%, compared with the laboratory result of 80.94%. A closer result of 78.73%, with a relative deviation of 2.73%, was obtained after adjusting the trapping anchor, although its mechanistic interpretation remains uncertain. The laboratory-reported reduction in residual oil saturation (Sor) from 0.1213 to 0.0762 has therefore not yet been fully reconciled with the applied physical frameworks. The polymer operating capillary number of 3.4–7.4 × 10?? remained below the critical desaturation threshold, while the literaturebased assessment indicated that an Sor of approximately 0.10 would be more consistent with the investigated conditions. In contrast, the SP simulation reproduced the laboratory recovery factor of 52.53% with a simulated value of 51.70%, corresponding to a relative deviation of 1.58%. Its operating capillary number of 4.4–6.3 × 10?³ exceeded the critical threshold, supporting residual-oil mobilization through interfacial-tension reduction. Overall, polymer flooding primarily provided mobility control and may also contribute to residual oil saturation reduction. However, additional parameter testing is required to evaluate its performance more comprehensively. In contrast, SP flooding provided an additional residual-oilmobilization mechanism. Repeated coreflood experiments and further upscaling are recommended before field-scale implementation