Research on loss rules of oil and gas in preserved shale cores after open air exposure

doi:10.3389/feart.2024.1375590

	Zhang, Jinyou 1,2; Wang, Min 3; Li, Jinbu 4; Liu, Zhao 2; Xu, Liang 2
	Research on loss rules of oil and gas in preserved shale cores after open air exposure
刊名	FRONTIERS IN EARTH SCIENCE
	2024-03-18
卷号	12 页码:12
DOI	10.3389/feart.2024.1375590
语种	英语
WOS研究方向	Geology
摘要	There is a large amount of oil and gas loss in traditional conventional core samples. Revealing the rules of oil and gas loss is of great significance for restore the pristine oil content and oil component in the shale. In this study, four preserved shale cores with different thermal maturity (R o = 1.01-1.53%) and different total organic carbon content (TOC = 1.69-5.48 wt.%) were selected. The samples are obtained from the first member of the Qingshankou Formation in the Gulong Sag. Nuclear magnetic resonance (NMR) T1-T2 mapping and thermal desorption gas chromatography (TD-GC, at a constant temperature of 300 degrees C for 3 min) were performed on the preserved cores and their replicas that were exposed in open air for different times, to study dynamic loss process and the molecular composition changes of shale oil. The results show that during exposure, shale experiences a large amount of oil loss, with a loss ratio of about 42%-78%, and the higher the maturity, the greater the loss ratio. The oil loss is mainly contributed by free oil, with a loss ratio as high as 88%. The adsorbed oil content, however, remains basically unchanged and has a good positive correlation with the TOC of shale. Once the cores were crushed, the gaseous hydrocarbon in oil was basically evaporated in just 5 min. After long-term storage, 90% of the C14- light hydrocarbon is lost, while the C14+ heavy hydrocarbon experiences basically no loss. Therefore, effective and timely analysis of preserved shales is extremely important. The oil content of uncrushed shale cores characterized by NMR T1-T2 mapping is much greater than that of the crushed sample measured by TD-GC, which means that NMR T1-T2 mapping can be important method to evaluate the original fluid saturation of shale.
关键词	shale oil light hydrocarbon loss NMR T1-T2 mapping preserved shale Gulong Sag
WOS记录号	WOS:001194516600001
收录类别	SCI
引用统计	正在获取...
文献类型	期刊论文
条目标识符	http://ir.gig.ac.cn/handle/344008/77176
专题	有机地球化学国家重点实验室
通讯作者	Wang, Min; Li, Jinbu
作者单位	1.Northeast Petr Univ, Sch Earth Sci, Daqing, Peoples R China 2.PetroChina Daqing Oilfield Co, Explorat & Dev Res Inst, Daqing, Peoples R China 3.China Univ Petr East China, Natl Key Lab Deep Oil & Gas, Qingdao, Peoples R China 4.Chinese Acad Sci, Guangzhou Inst Geochem, State Key Lab Organ Geochem, Guangzhou, Peoples R China
推荐引用方式 GB/T 7714	Zhang, Jinyou,Wang, Min,Li, Jinbu,et al. Research on loss rules of oil and gas in preserved shale cores after open air exposure[J]. FRONTIERS IN EARTH SCIENCE,2024,12:12.
APA	Zhang, Jinyou,Wang, Min,Li, Jinbu,Liu, Zhao,&Xu, Liang.(2024).Research on loss rules of oil and gas in preserved shale cores after open air exposure.FRONTIERS IN EARTH SCIENCE,12,12.
MLA	Zhang, Jinyou,et al."Research on loss rules of oil and gas in preserved shale cores after open air exposure".FRONTIERS IN EARTH SCIENCE 12(2024):12.