Carbonate Wettability Alteration: Core Flooding Test Under Reservoir Conditions with Carbonate Rock and Oil Samples from the Brazilian Pre-Salt

HIGHLIGHTS Evaluation of carbonates wettability modifier under Pre-Salt reservoir conditions. Rock and oil originating from the Brazilian Pre-Salt. Core flooding test under pre-salt reservoir conditions Carbonates wettability modifier. Surface agents can be used in different forms in upstream oil and gas production. One application is to enhance oil recovery by reducing interfacial tension (IFT) or changing the wettability of rocks from oil-wet (OW) to water-wet (WW). They can also be used for flow assurance purposes, preventing the deposition of inorganic scales. However, reducing IFT through surfactant application may lead to the formation of stable emulsions, complicating the separation of water from oil during primary processing. This study aims to evaluate the efficiency of a hydrotrope, specifically the phosphoric ester of glycerol (PEG-H), in increasing the hydrophilicity of carbonate petroleum reservoirs without significantly reducing IFT. The evaluation was conducted through a core flooding test to simulate pre-salt reservoir conditions, with a reservoir pressure of 6200 psi and a temperature of 84°C. The rocks and crude oil used in the test originated from the Brazilian pre-salt. The results demonstrate that the hydrotrope successfully enhances the hydrophilicity of carbonate rocks, resulting in an increased oil recovery factor, while maintaining a high IFT level.