3D Simulation of Low Salinity, Polymer, Conventional, Water-flooding & Combination IOR Methods – Heterogeneous & Varying Wetting Conditions

Abstract

Abstract In this paper a five spot well patterns is used to study Low Salinity, Polymer, Conventional, Water-flooding and the combination of Polymer flooding and LSWF. The aforementioned cases are applied under different wetting conditions. Oil recovery is a function of reservoir forces. Effective IOR implementation requires the proactive identification and contribution of the dominating reservoir forces, over the course of the field development. The work in this paper uses a validated, compositional simulator in addition to validated relative permeability and capillary formulations to simulate LSWF, PF, Conventional, Water-flooding and combination of PF + LSWF in a multi-dimensional, anisotropic and aerially heterogeneous model, under various wetting conditions. Wettability modification is also simulated using start and end relative permeability, captured and validated from literature. The initial wetting state is an important criterion for LSWF. The incremental recovery in oil-wet systems, or "typical carbonate reservoirs," is more rapid and thus requires less dilution of the injected brine salinity. In addition, simulation results indicate substantial un-swept quantities of available oil saturation. Therefore, the role of polymer flooding is examined along with conventional water-flooding in wetting conditions where LSWF may not achieve significant incremental recovery. LSWF is not effective in intermediate wetting conditions and Polymer flooding yields higher recovery factors in all water wet conditions. The impact of reservoir damage has an adverse effect on the development's recovery factor and polymer flooding yields the highest incremental recovery in case of low permeability formations. In oil wet conditions the performance of PF and LSWF is similar especially in weak oil wet systems due to the equal contribution of their respective displacement efficiencies. In strong oil-wet conditions the combination of PF + LSWF yields the highest recovery factor. The wetting conditions, formation heterogeneity and permeability magnitude all impact IOR selection and suggest that each oil reservoir has a unique ionic environment that changes naturally and by human intervention, therefore it is important to study different IOR methods at different stages of the field development.