Microstructure changes as a response to CO2 storage in sedimentary rocks: Recent developments and future challenges

A multiphysical‐geochemical coupling model for caprock sealing efficiency in CO2 geosequestration

“…When the diffusion time is shorter, more gas content diffuses from the fracture network into the matrix. This induces a faster increase in swelling strain and remarkably delays the propagation pace of the displacement front, thus significantly influencing the caprock sealing efficiency (Wang et al, 2023).…”

“…More and more studies have shown that CO 2 possibly migrates to shallow aquifers and pollutes freshwater resources (Carroll et al, 2014; Keating et al, 2013; Ruggieri & Gherardi, 2020; Smith et al, 2013; Takaya et al, 2017; Wang & Wang, 2018). This CO 2 leakage to freshwater layers may cause groundwater acidification (Apps et al, 2010), heavy metal mobilization (Frye et al, 2012), or mineral dissolution (Fazeli et al, 2019; Wang et al, 2023; Wang & Jaffe, 2004; Wasch & Koenen, 2019). Therefore, a comprehensive risk assessment of caprock integrity or caprock sealing efficiency is an essential task for CO 2 geosequestration safety.…”

“…Our previous study (Wang & Peng, 2014) developed a two-phase flow model which explored the effects of matrix sorption swelling on caprock sealing efficiency. However, subsequent studies found that the evolution of permeability by geochemical reactions cannot be ignored during the long-term geological sealing of CO 2 (Wang et al, 2023). Therefore, this study incorporated the geochemical reactions into our previous multiphysical coupling model to formulate a multiphysical-geochemical coupling model.…”

Control of Cement Timing, Mineralogy, and Texture on Hydro-chemo-mechanical Coupling from CO2 Injection into Sandstone: A Synthesis

“…Previous studies revealed different mechanisms behind these competing effects. Pore opening can be caused by mineral dissolution, cement degradation, and crack propagation, while pore closure can be caused by secondary precipitation, pressure solution, and stress compaction [19][20][21][22]. Previous works have examined the influence of numerous characteristics in controlling pore space evolution, including the abundance of carbonate, clay, and quartz; mineral surface area; migration of fines; injection rate; injection fluid concentrations, injection fluid temperature, and stress conditions.…”

“…Tutolo et al (2015) found that the precipitation of aluminum-rich secondary minerals in feldspar-rich sandstone can significantly affect the chemical kinetics and reduce permeability [26]. Pore throat blockage may be introduced by fine migration to significantly decrease permeability, although it causes limited change in porosity [22,27]. A slower injection rate (i.e., high Damköhler number) allows for a longer reaction time and enhances wormhole-type dissolution [13].…”