Evaluation of performance spectra of mono and divalent low saline brine injection in sandy-carbonates for mobilization of crude oil

Enhanced oil recovery mechanism with nanofluid injection

“…Как видно из вышеописанного единого мнения относительно того, какие механизмы являются доминирующими в повышении нефтеотдачи при закачке воды низкой солености, не существует [13].…”

Effects of brine valency and concentration on oil displacement by spontaneous imbibition: An interplay between wettability alteration and reduction in the oil-brine interfacial tension

“…Brine solutions of various formulae have been increasingly implemented in oilfields as displacing fluids for incremental oil displacement process [1]- [3], namely low-salinity enhanced oil recovery (EOR). Since 1990s, either brines diluted from connate water (salinity focused) or engineered brines with selective compositions added or deducted (brine-type concerned) were widely researched owing to their greener and cheaper than other conventional chemical EOR [4]- [7]. Although great efforts have been dedicated to understanding the mechanism and performance of low-salinity EOR from microscopic scale to field trials, dominant mechanisms and their contributions to oil displacement are barely conclusive due to variations in reservoir rock types and brine fluids compared [8]- [10].…”

“…Although great efforts have been dedicated to understanding the mechanism and performance of low-salinity EOR from microscopic scale to field trials, dominant mechanisms and their contributions to oil displacement are barely conclusive due to variations in reservoir rock types and brine fluids compared [8]- [10]. To date, a few microscopic low-salinity EOR mechanisms have been suggested, including reduction in the oil-water interfacial tension (𝜎), wettability alteration, mineral dissolution, fines migration, emulsification, and electrical double-layer expansion [7], [11]- [15], while their synergistic contribution or governing mechanism on the oil displacement has yet to be explicitly identified.…”

“…divalent CaCl2) at equivalent concentration. Such performance was mainly associated with changes in 𝜎 and wettability [7], [15], [16]. However, when considers these microscopic mechanisms contributed from two types of brine, their contributions are inconsistent or even conflict and hence designing brine fluids for EOR are such a dilemmatic challenge [17]- [19].…”

“…However, some studies suggested that the electrical double-layer expansion or increased repulsive electrostatic forces between oil-brine and brine-rock interfaces was attributed to improved oil displacement in waterflooding experiment, though monovalent NaCl brine was endorsed as highly effective displacing fluid rather than other divalent brines [6], [7]. Previous research that focused on effects of brine valency and concentration on oil displacement are summarized in Table 1.…”