Preparation of Cationic Fluoropolymer Emulsions and Their Applications as Novel Wettability‐Reversing Agents for Enhanced Oil Recovery

ABSTRACT During oil exploitation, severe water lock damage hinders the efficiency of resource extraction. Therefore, developing wettability‐reversing agents to improve reservoir wettability is important. In this study, new cationic fluoroacrylate emulsions (FED emulsions) were synthesized by incorporating a short‐chain fluoro‐monomer and a cationic monomer. Findings revealed that one of the FED emulsions exhibited excellent water solubility and adsorption properties. After treatment with 2.0 wt% FED emulsion, the water contact angle on the core surface increased from 84.3° to 130.2°, the kerosene contact angle increased from 1° to 70.3°, the surface free energy was reduced by 87.54%, and the discharge rate increased by 44.02%. The capillary self‐priming height was reduced by 30.56%. Core displacement experiments revealed that the FED emulsion reduced injection pressure while enhancing oil recovery, achieving a 14.91% improvement in recovery efficiency. The compatibility of the FED emulsion with polymer fracturing fluid was evaluated, and the results confirmed good compatibility between the two. Our findings establish the FED emulsion as an effective wettability‐reversing agent, capable of transforming reservoirs from hydrophilic and oleophilic to hydrophobic and oleophobic.