Modelling the Transport of Particulate Suspensions and Formation Damage during the Deep Injection of Supercritical Carbon Dioxide in Sandstone Formations
Résumé
Prediction of CO2 injection performance in deep subsurface aquifers and reservoirs rely on the well ability to maintain high flow rates of carbon dioxide during several decades without significantly impairing the host formation. Dynamics of solid particulate suspensions in permeable media are recognized as one major factor leading to injection well plugging in sandstones. The invading supercritical liquid-like fluid can contain variable concentrations of exogenous fine suspensions or endogenous particles generated in-situ by colloidal of hydrodynamic release mechanisms. Suspended solids can plug the pores leading to possible formation damage and permeability reduction in the vicinity of the injector. As such, models which can predict well injectivity decline are useful in the operations of planning, design, and maintenance, related to carbon dioxide injection. In this study we developed a finite element based simulator to predict the injectivity decline nearby CO2 injection wells and also for production wells in the context of EOR. The numerical model solves a system of two coupled sets of finite element equations corresponding to the pressure-saturation two-phase flow, then a system of solute and particles convection-diffusion equations. Particle equations are subject to mechanistic rate laws of colloidal, hydrodynamic release from pore bodies, blocking in pore bodies and pore throats, and interphase particles transfer. The model was validated against available laboratory experiments at the core scale. At the field scale, challenges still exist for an accurate assessment of the permeability change due to limited current knowledge of supercritical CO2 and water phase micro-interactions at pore surfaces, but also to the multiscale nature of the numerical problem. Numerical demonstration examples in a saline sandstone aquifer reveal that formation damage during CO2 injection will primarily depend on the injected particles wettability, the injection flow rate, and the medium tortuosity. Other simulation examples are provided for a CO2 injection in a five spots pattern EOR oil field for performance assessment of the production with occurrence of in-situ sanding in a poorly consolidated sandstone reservoir.