This work demonstrates enhanced oil recovery in fractured reservoirs using CO2-responsive gel and foam, indicating improved efficiency of CO2 flooding.
Key Points
The study aims to improve oil recovery in fractured reservoirs by employing a staged injection strategy with CO2-responsive materials.
Synthesized two types of CO2-responsive gels via free-radical polymerization.
Evaluated swelling ratios, rheological properties, and structural morphology of the gels.
Conducted core-scale enhanced oil recovery tests using artificial fractured cores.
The CR-DDN gel exhibited greater structural integrity and higher elastic modulus than CR-DAN.
Incremental recoveries of 14.5%–25.5% were achieved during gel injection, based on matrix permeability.
Using surfactant-alternating-gas cycles increased ultimate recovery to 76.91% compared to standard coinjection.