A numerical simulator developed for modeling permeability control for enhanced oil recovery

Water fingering phenomenon in an oil layer or water preferential injection into highly permeable layers in a multilayer reservoir often leads to a low sweep efficiency in a strong heterogeneous oil reservoir depending on water flooding for enhanced oil recovery (EOR). EOR by means of permeability control during water flooding periods in heterogeneous oil formations has been corroborated by previous experiments in the laboratory and field trial in mature oil fields. However, the quantitative relationships between EOR and permeability control in oil reservoirs are not clearly understood currently. In this paper, the mechanisms of permeability control in oil reservoirs were analyzed by theoretical approaches. Then, a three dimensional multi-phase flow mathematical model considering migration of solid permeability control agents (PCA) was presented. A numerical simulator for predicting multi-phase flow of permeability control in oil reservoirs was developed in Fortran codes. In addition, the permeability reduction and water-cut change induced by PCA calculated by the simulator are validated by experiments. Furthermore, a two and a three dimensional geological models with different types of permeability control agents injected into the highly permeable layer for EOR were studied by using the new simulator developed in this work. The simulation results demonstrate the permeability control processes with elapsed time as well as oil production performance influenced by permeability control. It also reveals a mechanism of permeability control for EOR, and suggests oil recovery improved by 4.9-8.8% in the 2D simulation and 6.1% in the 3D simulation example. It validates the feasibility of numerical simulation and importance of permeability control technology for EOR.