OICC Press International Journal of Energy and Environmental Engineering 2251-6832 14 4 (December 2023) 2023 01 05 Technical and economic feasibility assessment of low and high salinity water flooding: a simulation-based approach 10.1007/s40095-022-00556-8 EN Furqan Alvi Mari Petroleum Company Limited, Islamabad, PK Haris Ahmed Qureshi Mari Petroleum Company Limited, Islamabad, PK Journal Article 2023 01 05 Abstract Waterflooding is renowned improved oil recovery method worldwide to recover medium to light crude oil. LSWF is an emergent IOR method which reduces the quantity of residual oil saturation by implementing waterfloods of low salt concentration. LSWF can increment the oil recovery up to 10–20% compared to simple waterflooding. A synthetic 3D simulation model is generated in this study using commercial black oil simulator (Eclipse 100). Two base cases of low and high salinity water flooding are simulated, and impact of low salinity water flooding on FOE, FOPR, FOPT, FPR, FSPR, FSPT is analyzed. Sensitivity analyses of injection water salinity, relative permeability curves, grid refinement, Low salinity slug size and end point saturation effects are also conducted (LASLTFNC). LSWF enhances the oil recovery efficiency by 17% compared to HSWF. Sensitivity of wettability (relative permeability curves) exhibits maximum recovery of 75.96% in presence of strongly water wet system. Similarly, sensitivity of grid refinement exhibits variation in ultimate recovery of 5.24% between LSWF base case and refined grid case. Sensitivity of injection water salinity from 1000 to 35,000 PPM (sea water) results in ultimate recovery between 60.88 and 75.96%, respectively. The continuous injection of LS water is not economical for whole production life therefore the injection of slug can help in the withdrawal of almost similar volume of oil with better cost. Economic analysis of five different LSWF cases and one HSWF case is carried out to evaluate the most economically viable injection scenario. From case-1 to case-6, injection of low salinity water for 450 days followed by high saline water turns out to be the most optimum case with NPV of 20.422 million dollars.