Hybrid Carbonated Engineered Water as EOR Solution for Oil-Wet Carbonate Formation

Carbonated water has proven advantages over conventional CO2 injection in terms of arresting free mobility, low-pressure injection, lower volume requirement, and higher efficiency. The term “engineered water” is designated to selective ion-spiked with the advantage ion-exchange reactions rock minerals releasing trapped oil. This article investigated synergic effect dissolved engineered for oil recovery understanding inner mechanisms. Recovery efficiencies were evaluated through coreflood studies, which revealed that hybrid could recover 6–10% more than about 3% carbonated water. HP-HT pendant-drop studies show insignificance IFT reduction. Wettability change from wet near-water attributed as a significant factor. dissolution Ca2+ Mg2+ deposition SO42− observed coreflooding may have contribution recovery. Pore enlargement evidenced NMR-PSD NMR-ICP results support this claim. study confirmed EWI-CWI technique be promising EOR method, eliminating requirement high-pressure problems gravity segregation, early breakthrough CO2. It can also an effective solution, providing cost addition environmental benefits sequestration.