Reservoir characteristics of and potential analysis to Lower Palaeozoic shale in Xiuwu Basin, Lower Yangtze Plate

ABSTRACT

In order to evaluate reservoir characteristics and gas potential of organic-rich shale in Bottom-Lower Cambrian Hetang Formation and Upper Ordovician Xinkailing Formation, Xiuwu Basin, Jiangxi Province, Lower Yangtze Plate of China, researches regarding reservoir characteristics of organic-rich shale thickness, moderate burial depth, abundance and maturity of organic matter, fracturability, organic-matter pores and absorption performance have been conducted to Hetang Formation and Xinkailing Formation through field survey, shallow drilling, analysis to hydrocarbon-generation potential, scanning electron microscopy, measuring specific surface area and isothermal adsorption experiments. The results show that (1) Hetang Formation reservoir, although with extremely rich material basis, is of unfavorable hydrocarbon generation conditions due to late-stage thermal maturity, besides of undeveloped micropore structure, reservoir space development mainly by macroscopic crack, so further exploration should focus on locating favorable areas of low maturity and developed cracks, which is considered distributing in the core of Yanshan-Lingangshan-Shiziyan Mountains syncline; (2) Xinkailing Formation reservoir is of better organic matter abundance, pore development and absorption performance than Xinkailing Formation and hence further exploration should focus on surveying favorable areas of better sedimentary facies belt and stable structure for major breakthrough in shale-gas exploration, which is considered distributing in Wuning-Lixi and Jinkou-Tuolin areas.

KEYWORDS:

• Hetang Formation
• Xinkailing Formation
• hydrocarbon generating condition
• brittle mineral
• reservoir space
• adsorption gas volume
• resources prospect

Acknowledgements

Special thanks to Professor Wangshui Hu for his dedicated guidance, to Hengyu Lyu for the data statistics and analysis. This paper was supported by the National Natural Science Foundation of China [grant number 40872099] and the project ”shale gas resources evaluation of the Ministry of Land and Resources of Jiangxi Province, China” [grant number 2015104]. We are grateful to reviewers for helpful suggestions and constructive review.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [40872099];shale gas resources evaluation of the Ministry of Land and Resources of Jiangxi Province, China [2015104].