Journal
INTERNATIONAL JOURNAL OF COAL GEOLOGY
Volume 202, Issue -, Pages 109-127Publisher
ELSEVIER SCIENCE BV
DOI: 10.1016/j.coal.2018.12.007
Keywords
Supercritical CO2; Shale gas; Element mobilization; Pore structure; Fractal dimension
Categories
Funding
- National Natural Science Foundation of China [51741407]
- Project of the Shaanxi Province Science and Technology Program [2015KTCL01-08]
- National Major Research Program for Science and Technology of China [2016ZX05050006]
- Shaanxi Key Laboratory of Advanced Stimulation Technology for Oil & Gas Reservoirs, School of Petroleum Engineering, Xi'an Shiyou University
Ask authors/readers for more resources
There are many advantages to using supercritical carbon dioxide (ScCO2) fracturing technology to exploit shale gas reservoirs in China, including minimal damage to the environment or formation, and displacing methane (CH4) in the adsorbed state. When ScCO2 enters fractures in the formation, ScCO2-water-shale interactions may affect the physicochemical properties of shale. In this study, a high-pressure reaction system was adopted to simulate ScCO2-water-shale interactions under ScCO2 stimulation conditions. The element mobilization and pore structure before and after the reaction were measured using ICP-MS, XRF. The results show that the major elements, including Ca, Mg, Na, K, and Al, exhibit varying degrees of mobilization after the interactions because of dissolution of carbonate and silicate minerals in shale samples. Compared with the major elements, trace elements have a lower mobility, quantified as < 13.97%. The specific surface areas and pore volumes of two shale samples increase at different degrees after the reaction. The interactions have a more significant influence on the micropores. In addition, fractal features of the shale pore structure were analyzed. The fractal dimensions of the shale samples increase after the reaction, indicating that pore surface roughness increases, and pore structure morphology gradually transforms from regular to complex.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available