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DOI	10.1306/1213181614017139
	Generation and evolution of overpressure caused by hydrocarban generation in the Jurassic source rocks of the central Junggar Basin; northwestern China
	Guo X.; He S.; Liu K.; Yang Z.; Yuan S.; Liu M.
发表日期	2019
ISSN	0149-1423
起始页码	1553
结束页码	1574
卷号	103 期号:7
英文摘要	The Jurassic black mudstone and coal beds in the central Junggar Basin, northwestern China, are the major source rocks for the basin with type II2 and type III (gas-prone) kerogens. Widespread overpressures are developed in the Jurassic stratigraphic interval. Sonic and resistivity logs display strong characteristic responses of overpressure in the mudstones, with anomalously high acoustic traveltimes and low resistivity compared with the normally pressured mudstones. The overpressured Jurassic sediment sequences appear to have undergone normal compaction because the mudstones exhibit no anomalously low bulk density. The overpressured mudstones deviate from the normally pressured mudstones in density-effective vertical stress space. The overpressure in the Jurassic source rocks is, therefore, not caused by disequilibrium compaction. The overpressured Jurassic sandstone reservoirs are predominantly oil and gas saturated or oil bearing. The well-log responses of the overpressured mudstones and seismic velocity characteristics indicate that the top depth of the overpressure zone ranges from3800 to 4600m(12,500 to 15,100 ft), corresponding to formation temperatures of approximately 94°C to 111°C (∼201°F to 232°F), with estimated vitrinite reflectance values of 0.6% to 0.75%. The Jurassic source rocks with overpressure are capable of generating hydrocarban at present and are currently overpressured. All the evidence suggests thatthe overpressure in the Jurassic source rocks in the central Junggar Basin is caused by hydrocarbon (HC) generation. The overpressure evolution was modeled quantitatively in response to pressure changes caused by HC generation during basin evolution. The results indicate that multiple episodes of overpressure development and release occurred within the Jurassic source rocks, suggesting multiple episodes of HC expulsion. The timing and numbers of these episodes of HC expulsion were thus determined from the modeled overpressure evolution. © 2019. The American Association of Petroleum Geologists.
语种	英语
scopus关键词	Coal deposits; Compaction; Economic geology; Electric logging; Landforms; Oil bearing formations; Petroleum reservoir engineering; Reflection; Sedimentary rocks; Stratigraphy; Formation temperature; Jurassic sediments; Northwestern China; Resistivity logs; Sandstone reservoirs; Seismic velocities; Stratigraphic intervals; Vitrinite reflectance; Oil well logging; hydrocarbon generation; Jurassic; kerogen; mudstone; sandstone; seismic velocity; source rock; vitrinite reflectance; China; Junggar Basin; Xinjiang Uygur
来源期刊	AAPG Bulletin
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/143790
作者单位	Key Laboratory of Tectonics and Petroleum Resources, Ministry of Education, China University of Geosciences, Wuhan, China; Department of Petroleum Geology, Faculty of Earth Resources, China University of Geosciences, Wuhan, China; China University of Petroleum, Qingdao, China; Laboratory for Marine Mineral Resources, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China; Research Institute of Petroleum Exploration and Development (RIPED), PetroChina, Beijing, China; RIPED, PetroChina, Beijing, China; Department of Geology and Geophysics, University of Wyoming, Laramie, WY, United States
推荐引用方式 GB/T 7714	Guo X.,He S.,Liu K.,et al. Generation and evolution of overpressure caused by hydrocarban generation in the Jurassic source rocks of the central Junggar Basin; northwestern China[J],2019,103(7).
APA	Guo X.,He S.,Liu K.,Yang Z.,Yuan S.,&Liu M..(2019).Generation and evolution of overpressure caused by hydrocarban generation in the Jurassic source rocks of the central Junggar Basin; northwestern China.AAPG Bulletin,103(7).
MLA	Guo X.,et al."Generation and evolution of overpressure caused by hydrocarban generation in the Jurassic source rocks of the central Junggar Basin; northwestern China".AAPG Bulletin 103.7(2019).