Investigation of surfactant-polymer flooding simulation using two-phase and three-phase microemulsion phase behavior models

The vast global demand for energy coupled with the decreasing oil production capabilities of maturing fields raises the need for Enhanced Oil Recovery (EOR) technologies. Much of the oil in these maturing fields are yet to be extracted and remains in the reservoir as residual oil. Chemical EOR (CEOR) is a widely known and effective method in extracting the remaining oil in the reservoir post-secondary flooding. Surfactant-polymer flooding is a type of CEOR that enhances oil recovery by applying mobility control, forming micelles, and reducing interfacial tension. Simulation of CEOR floods before field application is essential to avoid deployment obstacles and to ensure the good design of the chemical formulations. In this thesis, reservoir simulators that utilize two-phase microemulsion model (CMG-STARS) and three-phase microemulsion model (UTCHEMRS & INTERSECT) are used to simulate surfactant-polymer flooding to determine and compare their results. Different models are used in the simulators to describe the physical behavior of injected chemicals inside the reservoir. Therefore, these models were examined and matched when possible. An extensive study was performed on the relative permeability models of INTERSECT and UTCHEMRS. For simulations, the physical behavior models of polymer and surfactant were constructed and validated on a 1D scale reservoir model. Then, the reservoir model was extended to a 3D model, where the physical models and results were further validated. Finally, simulations were conducted in a field-scale reservoir containing 680,400 grids, where results were compared and analyzed. The results for the relative permeability study demonstrated that the INTERSECT relative permeability model is complex, and more information is required to follow the sequence of equations and their dependencies. For the simulation, the 1D and 3D model results suggest an excellent match between the different simulators in modeling surfactant-polymer floods. In the case of the field-scale model, the simulators matched in terms of oil recovery and produced and injected total fluids while having similar average reservoir pressures.