Coupled Numerical Simulation of CO2 - EOR Flooding: Integrating Multiphysics Interactions.

Area of Science:

• Petroleum Engineering
• Chemical Engineering
• Geoscience

Background:

• Carbon dioxide-enhanced oil recovery (CO2-EOR) is crucial for hydrocarbon field development.
• Understanding multiphase saturation dynamics during CO2 displacement is key.
• Accurate modeling is needed to optimize EOR processes and carbon sequestration.

Purpose of the Study:

• To develop a novel computational framework for simulating CO2-EOR.
• To quantify the spatiotemporal evolution of multiphase saturations.
• To analyze the impact of various physical and chemical factors on CO2 displacement.

Main Methods:

• Developed a 1D triple-phase mathematical model using Darcy's law and mass conservation.
• Employed an implicit pressure-explicit saturation (IMPES) finite-difference scheme.
• Incorporated chemical reaction kinetics, viscosity-pressure coupling, and dynamic relative permeability.

Main Results:

• Simulations revealed pore-throat dilation due to CO2-rock interactions, increasing flooding radii.
• Wellbore-formation pressure differentials were found to control CO2 plume propagation and annulus thickness.
• Increased reservoir porosity reduced confinement and displacement efficiency, despite higher throughput.

Conclusions:

• CO2-EOR injectivity parameters can be optimized based on simulation findings.
• Long-term carbon sequestration integrity in heterogeneous formations can be improved.
• The study bridges theoretical modeling with practical field-scale implementation strategies.