Role of Monovalent and Divalent Ions in Low-Salinity Water Flood in Carbonate Reservoirs: An Integrated Analysis through Zeta Potentiometric and Simulation Studies

The presence of principal ions in the water injected is essential for enhanced oil recovery by formation water-wet state carbonates. This study reaffirms this and presents an evaluation positive influence both divalent as wells monovalent on wettability alteration mechanisms during low salinity waterflooding using brines varying ionic composition, referred to “smart brines”. Zeta potentiometric analysis reservoir simulation studies were conducted with diluted smart that prepared composition ions. Surface charge oil-saturated whole core samples rock various was estimated zeta potential measurements. A comprehensive done establish investigate linkage between mechanism incremental achieved. It noted increases increasing level dilution it can be attributed electric double-layer mechanism. On contrary, implied a different where increase effluent’s pH Ca2+ mole fraction along decrease moles minerals saturation index dissolution dominant Moreover, effect mineral beyond injection block highly doubtful. demonstrates integrated approach from used provide insights into underlying science interactions at pore scale waterflood brines. With aid adequately designed upscaling procedure protocol, laboratory results further towards developing field-scale models obtain realistic factors optimized brine salinity.