Reduced Physics Modeling of CO2 Injectivity
Abstract
Understanding pressure and plume propagation in the reservoir is an essential component of feasibility and risk assessment of geologic carbon sequestration operations. Detailed numerical simulations of supercritical CO2 injection in deep saline aquifers generally involve extensive reservoir characterization and high computational effort. Validated simplified models that are based on the most critical physical processes, on the other hand, can be efficient alternatives for rapid screening of CO2 sequestration projects. Sensitivity analysis using a set of well-designed full-physics compositional simulations provides useful insight regarding parameter influences on pressure propagation in our domain of interest. We developed a robust 2D simplified physics model to characterize CO2 injectivity in semi-confined layered saline aquifer systems as a function of dimensionless variables characterizing rock and fluid properties based on sensitivity analysis results. Our simplified model for injectivity can thus be used to determine the CO2 injection rate for a given target pressure differential or alternatively, the pressure differential resulting from injecting CO2 at a target rate.
Keywords: Screening; Sensitivity analysis; Simplified physics model; CO2 injectivity
