English
 
Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
Add to Basket
  DetailsSummary

Released
Journal Article

Prediction of the gas-generating characteristics of the Qiongzhusi and Longmaxi Formations, Yangtze Platform, southern China, using analogues

Authors
/persons/resource/horsf

Horsfield,  B.
3.2 Organic Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Zou,  Caineng
External Organizations;

Li,  Jian
External Organizations;

/persons/resource/henryang

Yang,  Shengyu
3.2 Organic Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

/persons/resource/nick

Mahlstedt,  Nicolaj
3.2 Organic Geochemistry, 3.0 Geochemistry, Departments, GFZ Publication Database, Deutsches GeoForschungsZentrum;

Misch,  David
External Organizations;

Gross,  Doris
External Organizations;

Wei,  Ma
External Organizations;

Wang,  Yifeng
External Organizations;

Tan,  Yingqiang
External Organizations;

External Ressource
No external resources are shared
Fulltext (public)
There are no public fulltexts stored in GFZpublic
Supplementary Material (public)
There is no public supplementary material available
Citation

Horsfield, B., Zou, C., Li, J., Yang, S., Mahlstedt, N., Misch, D., Gross, D., Wei, M., Wang, Y., Tan, Y. (2020 online): Prediction of the gas-generating characteristics of the Qiongzhusi and Longmaxi Formations, Yangtze Platform, southern China, using analogues. - AAPG Bulletin.
https://doi.org/10.1306/11182018244


Cite as: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5004695
Abstract
China has been said to have the largest putative shale gas resources in the world. The highest potential occurs in the Sichuan Basin, with the overmature Qiongzhusi (Cambrian) and Longmaxi (Silurian) Formations as prime exploration targets. Here the likelihood of late gas formation is examined using less mature equivalents from the Georgina Basin (Australia), and the Baltic Basin (Lithuania). We consider the respective roles played by kerogen and polar bitumen in gas generation with reference to the Eagle Ford, Yanchang, Niobrara, and Vaca Muerta Formations. Both of the lower Paleozoic shales are bitumen-poor in a geochemical sense, this being in stark contrast to the Mesozoic shales which are bitumen-rich. Kerogen is, therefore, the major gas precursor in the Cambrian and Silurian of the Sichuan Basin. Graptolites and solid bitumen are petrographically dominant. The solid bitumen exhibits flow structures and is deduced to be highly polar because it is insoluble in dichloromethane. Secondary cracking kinetics determined for the Arthur Creek using the GORfit Model are closely similar to source rocks containing predominantly paraffinic oil. Late gas generation from very stable refractory kerogen structures via alpha-cleavage reactions at maturities above 2% equivalent vitrinite reflectance was verified, and importantly, the upper ceiling for late gas generation in Paleozoic shales of the Sichuan Basin is set at 3% Ro. As far as the Qiongzhusi shale is concerned, raising the prospective acreage to a 3% Ro limit brings an additional contribution of 40 mg HC/g total organic carbon of late gas charge. The same is true for the extensive fairway of the Longmaxi shale along the western flank of the basin, close to the subcropping erosional edge.