Numerical Analysis Of Immiscible/Near-Miscible CO2-WAG Displacement, Incorporating Compositional And Interfacial Tension Effects

Abstract

Summary The central objective of this paper is to study the balance and interactions of the different mechanistic contributions to the physics occurring during oil displacement by CO2 (both continuous and WAG). Mechanism 1 (M1) is the conventional oil stripping/compositional effect and Mechanism 2 (M2) is the near-miscible IFT effect on oil relative permeability through enhanced layer flow. Using sufficiently fine-scale models, we explain how these mechanisms interact with each other and affect the sweep and local displacement efficiency in a heterogeneous permeability field. We believe that studying the key processes separately leads to a greater insight into the physics of CO2 displacement, and this will help us to simulate the transition from immiscible to miscible displacement consistently at larger scales.