Ordovician deep dolomite reservoirs in the intracratonic Ordos Basin, China: Depositional model and Diagenetic evolution
- Resource Type
- Authors
- Zhongtang Su; Hongde Chen; Shuai Yang; Shenglin Xu; Anqing Chen; Sihan Hu; Yijiang Zhong
- Source
- Energy Exploration & Exploitation, Vol 36 (2018)
- Subject
- Renewable Energy, Sustainability and the Environment
business.industry
020209 energy
Dolomite
lcsh:TJ807-830
Geochemistry
lcsh:Renewable energy sources
Energy Engineering and Power Technology
02 engineering and technology
Structural basin
010502 geochemistry & geophysics
01 natural sciences
Diagenesis
Sedimentary depositional environment
lcsh:Production of electric energy or power. Powerplants. Central stations
Fuel Technology
Nuclear Energy and Engineering
Natural gas
lcsh:TK1001-1841
0202 electrical engineering, electronic engineering, information engineering
Dolomitization
Ordovician
business
Geology
0105 earth and related environmental sciences
- Language
- English
- ISSN
- 2048-4054
0144-5987
Recent natural gas discoveries indicate that non-karstification-dominated reservoirs exist in the intracratonic Ordos Basin. This study examines the sedimentological and geochemical characteristics needed to clarify the depositional model and diagenetic evolution process of this newly discovered reservoir type. The depositional environment of the dolomite reservoir can be characterized as a tidal flat that grew from the Central Paleo-uplift to the eastern depression by cyclic progradation on an epeiric platform. A tidal flat sequence can extend laterally as a progradational wedge in each cycle of sea level fluctuation. The sheet-shaped peritidal shoal facies associations patched on the wedge represent potential dolomite reservoirs and can be recognized by the presence of doloarenite that has been altered into a vaguely relict grained-texture by diagenesis. Although continuing destructive diagenesis has led to reservoir densification, burial dolomitization and burial dissolution with facies selectivity have tended to occur in peritidal shoal facies associations, thus improving the quality of the dolomite reservoirs. These models provide new insights for targeting deep dolomite hydrocarbon reservoirs in intracratonic basins.