Perpustakaan Digital ITB

Mature oil fields typically recover less than 50% of the original oil in place (OOIP) after primary and secondary recovery. To overcome this limitation, Low Tension Polymer Flooding (LTPF) has been proposed as one of the enhanced oil recovery (EOR) methods. LTPF integrates the mobility control effect of polymer with the interfacial tension (IFT) reduction capability of surfactant. This study evaluates the potential application of LTPF in the “B” Structure on the onshore “S” Field. Reservoir simulations were conducted using tNavigator!" on a model comprising four production wells (B-1 to B-4) and seven injection wells (INJ-1 to INJ-7) arranged in a regular five-spot pattern. Various injection scenarios were tested, including polymer concentrations of 0.175 to 0.7 lb/stb, as well as surfactant concentrations of 0.175 lb/stb to 0.35 lb/stb. The effects of surfactant flooding were represented by modifying relative permeability curves to reflect reductions in IFT, which in turn decrease residual oil saturation (????#$). The simulation results revealed that polymer flooding implemented independently was the most effective EOR method for the “B” Structure. At a polymer concentration of 0.7 lb/stb and an injection rate of 250 stb/d per injector, the recovery factor increased from 59.9% under baseline conditions to 64.02%, demonstrating that polymer flooding had a more significant impact on oil recovery compared to the other tested scenarios. In contrast, the LTPF cases combining polymer with low surfactant concentrations did not provide meaningful incremental oil recovery within the tested range. These findings suggest that, under the given reservoir conditions, polymer concentration plays a more dominant role than surfactant addition, and that implementing polymer flooding independently may represent a more practical EOR strategy.