A new rigorous mathematical model to describe immiscible CO₂-oil flow in porous media

The immiscible carbon dioxide flooding process has received considerable interest in the literature. Numerous laboratory experiments were conducted to determine the improved oil recovery through this process. However, little attention has been paid to modeling the process appropriately and mimicking actual physical phenomena of CO₂-oil immiscible flow in porous media. Development of accurate models for immiscible CO₂-oil flow will enhance the understanding of the process, assist in the design and interpretation of sophisticated laboratory experiments, and provide better guidelines for field implementation. Therefore, a new mathematical model is developed to represent immiscible CO₂-oil flow in porous media within a secondary recovery mechanism. During the development of the model equation, a one-dimensional, twophase immiscible fluid flow is considered. The model equation is then discretized using the IMPES concept and solved numerically utilizing MATLAB programming. The performance of the model equation was confirmed by analyzing the behaviors of relative permeability, fractional flow, and pressure curves. It is also established that longer exposure time of CO ₂ enhances oil recovery. The numerical results demonstrate that the new mathematical model is capable of predicting oil displacement and sweeping efficiency more realistically.