Mechanistic Modeling of Gel Microsphere Surfactant Displacement for Enhanced Oil Recovery after Polymer Flooding

The gel microsphere is an effective profile control agent to mitigate water-channeling problems in mature oil reservoirs. Recently the gel microsphere combined with high effective surfactant is proposed to enhance oil recovery after polymer flooding. Although some experimental and field studies have demonstrated the synergistic effect of polymer/gel microsphere/surfactant, there are no relevant models that can handle the combined effects. Hence, mechanistic modeling is needed for EOR after polymer flooding. In this work, the transport properties of gel microspheres are combined with polymer and surfactant model. In the coupled model, the migration mechanisms and retention controlling factors of gel micro-spheres are analyzed according to lab tests, which resulted in the development of the filtration migration equation and dynamic permeability model. The interaction mechanisms between gel microsphere and polymer/surfactant are mathematically described according to experiments, in which the surfactant model is implemented based on a model implemented in a commercial simulator. The coupled model is numerically solved by an implicit-pressure, explicit-compositions (IMPEC) method. The surfactant module is verified with a commercial simulator. The robustness of the coupled model is also validated with a core flooding case to reproduce injection pressure. Furthermore, the coupled model provides an efficient method for predicting gel microsphere-surfactant flooding performance, which helps to determine the technical feasibility of the project. The interaction between gel microsphere and surfactant is modeled for EOR performance prediction in this work. The newly presented model will help to improve our understanding of the gel microsphere/surfactant flooding