Global warming brings a tremendous threat to the sustainability of human society. Reducing the emissions of carbon dioxide (CO
2) is a common challenge for countries worldwide. The geological storage of CO
2 is regarded as a direct and effective emission reduction method by the international community. However, due to the high cost and public concerns of geological disaster, underground water pollution and damage to ecosystems, the successful CO
2 geo-storage projects are still rare.
To advance the application of CO
2 geo-storage, we need to make this technology more environment-friendly and economically feasible. The CO
2-enhanced shale gas recovery technique (CO2-ESGR), which injects CO
2 into shale reservoirs, can provide dual benefits by enhancing shale gas recovery and securing geological sequestration of CO
2. Theoretically, based on the stronger adsorption capacity of CO
2 on shale surface, injected CO
2 can displace adsorbed CH
4 out of micropores. This phenomenon is the basis of CO2-ESGR. Although this technology is very promising, it is still in a very early stage of deployment. Many key issues need to be addressed, including the dynamic process of the competition adsorption of CO
2 and CH
4 on shale, the supercritical/liquid CO
2 fracturing method, the multiscale and multiphysics behaviors between different materials, etc.
This Research Topic aims to highlight the state-of-art findings in thermo-hydro-mechanical-chemical (THMC) coupling behaviors between shale, CO
2 and CH
4 from grain scale to microscopic scale, and to the macroscopic scale for engineering applications. Original theoretical research articles, review articles, and case studies are welcomed to submit.
Potential topics include but are not limited to the following:
- The impact of supercritical CO2 on shale properties,
- The interaction of CO2 and CH4 in shale,
- Finite element, finite difference, discrete element, and coupled numeric modeling approaches,
- Multiphysics and multiscale constitutive models of shale,
- Quantitative descriptions of the microscopic topological structures,
- The mechanism of supercritical/liquid CO2 fracturing method,
- The evaluation of shale gas recovery efficiency.
