Supercritical CO2 fracking for enhanced shale gas recovery and CO2 sequestration: Results, status and future challenges

Supercritical carbon dioxide(ScCO2)-based fracturing technology associating with CO2 enhanced shale gas recovery is a promising technology to reduce the water consumption of shale gas production and could provide the potential for CO2 sequestration. Advancing the understanding of complex gas shale reservoir behavior in the presence ofmultiphase and multicomponent gases (ScCO2, gaseous CO2 and CH4 etc.) via laboratory experiments, theoretical model development and field validation studies is very important. In this paper, the progress of some key scientific problems such as the mechanism of ScCO2 drilling and completion, the ScCO2 fracturing technology, the competition adsorption behaviors of CO2/CH4 in shale, the coupled multiphase and multicomponent CO2/CH4 flow during the CO2 enhanced shale gas recovery process and the CO2 sequestration potential in shale formation were discussed. Finally, the challenges of the technique will face and the further research is needed in the future is also exposed.Cited as: Zhou, J., Hu, N., Xian, X., Zhou, L., Tang, J., Kang, Y., Wang, H. Supercritical CO2 fracking for enhanced shale gas recovery and CO2 sequestration: Results, status and future challenges. Advances in Geo-Energy Research, 2019, 3(2): 207-224, doi: 10.26804/ager.2019.02.1