Abstract
In this study, the main investigated injection parameters include the relationship between the salinity of the injected fluid, surfactant concentration, and the quality of the injected foam, as well as their influence on oil mobility in the porous medium and displacement efficiency. Qualitative evaluation of the results was performed based on the analysis of the oil recovery factor, the oil fraction in the produced stream, the time of oil bank breakthrough, as well as the salinity of the produced fluid and pressure drop characteristics. The efficiency of a low-interfacial-tension gas injection method was investigated in low-permeability (<10 mD) carbonate reservoirs under conditions of high formation water salinity and elevated concentrations of divalent ions (Ca²+, Mg²+). Pressure drop data demonstrated uniform oil displacement along the core and confirmed lower pressure losses compared with water injection. In addition, the effect of dissolved oil on foam stability was analyzed, showing that an increase in salinity leads to micelle swelling and a reduction in foam stability. The obtained results confirm that the SorLTG method is a promising enhanced oil recovery technology for complex geological conditions and highly saline formation waters.