Effect of water softening on polymer adsorption on carbonates through single-phase and two-phase studies

摘要: Polymer retention is considered as a major challenge in polymer flooding application, especially in carbonates, due to the prevailing harsh conditions of low permeability (< 100 mD), high temperature (> 85 °C), and high salinity (>100,000 ppm). One of the many advantages of smart water technology is maintaining the viscosity of polymers for water-based Enhanced Oil Recovery (EOR) techniques. This research focuses on the effect of water softening on the performance and adsorption of an ATBS-based polymer in carbonate reservoirs. Four different brine recipes were investigated with the salinity of 8,000 ppm TDS and varying ionic composition designed mainly by eliminating the hardness-causing ions, including Ca2+ and Mg2+. A geochemical study was performed using the PHREEQC software to analyze the interaction between these injected brines and the rock. Further, comprehensive rheological and …