Predicting time-dependent scale-induced permeability reduction in water flooding: Kinetic modeling and inhibitor effectiveness under reservoir conditions

Water flooding is a key enhanced oil recovery technique for boosting oil production from depleted reservoirs. However, mixing incompatible fluids leads to mineral scale formation. Scales such as calcium carbonate and strontium sulfate pose risks to reservoir integrity and productivity. Selecting suitable water compositions and inhibitors is essential to prevent scale-induced permeability reduction. This study innovates by integrating long-term experiments up to 21 days with PHREEQC-MATLAB modeling to evaluate time-dependent scale formation kinetics under reservoir conditions in carbonate reservoirs, addressing a gap in prior equilibrium-focused research that overlooks progressive deposition. Time dependence plays a pivotal role by revealing kinetic progression, with scale buildup stabilizing after 7 days and yielding 15–20% more deposition than short-term analyses, enabling accurate long-term risk predictions; this is influenced by time with driving nucleation and growth rates, temperature on enhancing carbonate solubility changes, pressure with affecting sulfate supersaturation, and water composition on altering ion interactions and mixing ratios, which collectively amplify the innovation through cross-validated insights into dynamic scale behavior not captured in static studies. Scale inhibitors evaluation optimizes concentrations for maximum efficacy while identifying alternatives to mitigate secondary operational risks. Among tested inhibitors, H+PA proved most effective, achieving 98% inhibition in static tests and limiting permeability loss to 37% in corefloods. ICP analysis confirmed reduced calcium/strontium ions, underscoring the inhibitor’s efficacy. SEM revealed calcite and strontium sulfate crystals, with EDAX verifying compositions, illustrating time-dependent nucleation/growth driving permeability decline. These findings optimize water injection, improve scale understanding, and support cost-effective, safer practices in oilfield operations. • Integrated PHREEQC-MATLAB for time-resolved scale kinetics over time • 15-20% more deposition in long-term tests compared to short-term equilibrium • H+PA inhibitor achieves 98% efficiency, limits permeability loss to 37% • Seawater fraction study optimizes injection, cutting pollutant loads in effluents • SEM/EDAX confirms calcite/strontium sulfate, aiding contaminant risk assessment