Integrated simulations of CO₂ spreading and pressure response in the multilayer saline aquifer of South Scania Site, Sweden

Abstract

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.

Assessment of Trapping Mechanisms of CO2 Sequestration and Optimization of Key Process Parameters in a Deep Saline Aquifer Using Reservoir Simulation and Response Surface Methodology

“…Figure 6b shows the areal sweep with combined CO 2 (at the bottom) and water injection (at the top) due to which upward migration of the buoyant CO 2 was hindered along with reduction in CO 2 channeling resulting in enhanced dissolution of CO 2 in brine. The result can be correlated with the findings of Joodaki et al [34], which showed that CO 2 trapping is enhanced with CO 2 -brine co-injection. So, the mobile CO 2 concentration was the least.…”

Gaussian process emulators for quantifying uncertainty inCO2spreading predictions in heterogeneous media

“…Carefully conducted numerical simulations are critical for the understanding of the associated coupled physical and chemical processes (Pruess and García, 2002;Juanes et al, 2006;Doughty, 2007;Dai et al, 2016;Bacon et al, 2016;Xiao et al, 2016). An important additional complication arises from the geological heterogeneity of the target formation, such as stratigraphic architecture and facies distribution, which is difficult to estimate from the limited number of observations available (i.e., from the sparse networks of primarily vertical investigation wells) in a deterministic manner (Ambrose et al, 2007;Tsang et al, 2008;Gershenzon et al, 2015;Ritzi et al, 2016;Tian et al, 2016b;Ampomah et al, 2016). Therefore, robust and computationally effective methods for dealing with the uncertainty arising from the geological heterogeneity are in great need.…”