A review of geochemical–mechanical impacts in geological carbon storage reservoirs

Abstract

Geological carbon storage (GCS) refers to the technology of capturing man‐made carbon dioxide (CO2) emissions, typically from stationary power sources, and storing such emissions in deep underground reservoirs. GCS is an approach being explored globally as a defense mechanism against climate change projections, although it is not without its critics. An important focus has been recently placed on understanding the coupling between rock–fluid geochemical alterations and mechanical changes for CO2 storage schemes in saline aquifers. This article presents a review of the current state of knowledge regarding CO2‐induced geochemical reactions in subsurface reservoirs, and their potential impact on mechanical properties and microseismic events at CO2 storage sites. This review focuses, in particular, on the current state of the art in fluid–rock interactions within the GCS context. Key issues to be addressed include geochemical reactions and the alteration of transport and mechanical properties. Specific review topics include the swelling of clays, the prediction of dissolution and precipitation reaction rates, CO2‐induced changes in porosity and permeability, constitutive models of chemo–mechanical interactions in rock, and correlations between geochemical reactions and induced seismicity. The open questions in the field are emphasized, and new research needs are highlighted. © 2019 Society of Chemical Industry and John Wiley & Sons, Ltd.

Statistical based hydromechanical models to estimate poroelastic effects of CO2 injection into a closed reservoir

“…For example, to predict the I-stress increase using reduced-order model, it is not necessary to have an estimate of caprock Poisson's ratio. The plots of actual versus predicted values, the residual plots, and the tables for the coefficients of quadratic polynomials and reduced-order polynomials for surface uplift, I-stress (horizontal stress), and K-stress (vertical stress) are presented in Supporting Information Appendices B and C. Equations (3)- (5) show the regression with only significant parameters for the surface uplift (Resp-SU), reservoir horizontal stress increase (Resp-IS), and the vertical stress increase (Resp-KS): Figure 7(a) shows the response surface plot for surface uplift as a function of reservoir wellbore block pressure and reservoir Young's modulus. Figure 7(b) shows the response surface plot with wellbore block pressure and reservoir depth as inputs.…”

“…Equations (2)- (5) show that the interaction of input parameters to make each response model is complex (by including several terms) and nonlinear. As a result, it is not straightforward to understand the importance of each input parameter on the responses by simply analyzing the derived regression-based equations.…”

“…Understanding the geomechanical outcomes of CO 2 sequestration into geological formations is necessary since it affects CO 2 injectivity, reservoir mechanical integrity, and safety of the potential injection site . To ensure that the mechanical integrity of the reservoir caprock system is maintained during injection, in situ stress changes caused by pore pressure changes (i.e., poroelastic effect of injection) should be investigated .…”

“…C potential injection site. [1][2][3][4][5] To ensure that the mechanical integrity of the reservoir caprock system is maintained during injection, in situ stress changes caused by pore pressure changes (i.e., poroelastic effect of injection) should be investigated. 6 Poroelastic effects…”

Impact of mineral composition and distribution on the mechanical properties of porous media

“…As time progresses, secondary minerals may precipitate from released ions, again altering the properties of the formation. The impact of the mineral dissolution and precipitation reactions on formation properties, including strength, however, is not well understood [9].…”