Fast Evaluation of Fluid-rock Coupling in CO2 Storage

Modelling plays an important role in providing capacity estimates and analysing injectivity, long-term safety and risk factors for future storage sites. Hundreds and thousands of potential sites will have to be screened for suitability before more detailed studies are done. In this context, fast yet reliable methods will have to be developed involving simplified models but without losing too much of the accuracy. One key parameter for choosing a storage site is the injectivity; how fast can the CO2 be injected. The basics of hydro-mechanical modelling is explained and a conceptual model for single-phase fluid flow is defined. Various levels of complexity of the governing equations are derived, by considering standard methods and using constant and non-linear hydro-mechanical properties these models are compared. Results show that well defined input data makes the coupling to the geomechanical processes redundant, resulting in considerable savings in computational effort to get reliable and accurate estimates of injection pressure.