Carbon dioxide (CO2) injection in deep saline formations causes pressure increase which may be detrimental to the mechanical integrity of the storage reservoir. Injection induced pressure build‐up is a limiting factor for CO2 injection rates and storage capacity. In this study, we extend a semi‐analytical solution (based on one‐dimensional, two‐phase, two‐component radial flow) for application to estimate pressure build‐up and maximum injection rate of CO2 at a field site (South Scania, Sweden) using the method of superposition of image well solutions to account for the straight‐line boundaries imposed by three fault zones. The semi‐analytical approach for estimating pressure build‐up is validated by comparison to numerical simulations based on TOUGH2‐ECO2N. We analyze injection pressure sensitivity due to uncertainty in reservoir parameters as well as boundary conditions. Maximum injection rates and pressure limited capacity estimates are presented. This work demonstrates the use of semi‐analytical solutions to analyze pressure limitation on storage capacity for realistic reservoirs with irregular (non‐circular) boundaries. It is also shown that the semi‐analytical approach can also be used to evaluate the benefit of having multiple injection wells in terms of increasing the injection‐pressure‐limited storage capacity. The methodology presented in this study is useful for screening analysis of storage sites as well as for operation design and optimization where pressure build‐up as a limiting factor influences the objective function.

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An integrated modeling approach/workflow, in which a series of mathematical models of different levels of complexity are applied to evaluate the geological storage capacity of the Scania Site, southwest Sweden, is presented. The storage formation at the site is a layered formation limited by bounding fault zones, and injection is assumed to take place from one existing deep borehole into all layers. A semi‐analytical model for two‐phase flow is first used to evaluate the pressure response and related parameter sensitivity, as well as the first estimates of acceptable injection rates. These results are then used to guide the more detailed numerical simulations that address both pressure response and plume migration. The vertical equilibrium (VE) model is used to obtain a preliminary understanding of the plume migration with a larger number of simulations. Finally the full TOUGH2/ECO2N simulations are performed for the most detailed analyses of pressure responses and plume migration. Throughout, the results of the different modeling approaches are compared to each other. It is concluded that the key limiting factor for the storage capacity at the site in the injection scenario considered is the fast CO2 migration within the high permeability layer. Future studies can address alternative injection scenarios, including using horizontal injection wells and injection to other layers than the high permeability layer.