| Title | Analysis of Lower Cambrian shale gas composition, source and accumulation pattern in different tectonic backgrounds: A case study of Weiyuan Block in the Upper Yangtze region and Xiuwu Basin in the Lower Yangtze region |
| Authors | Zhang, Kun Jia, Chengzao Song, Yan Jiang, Shu Jiang, Zhenxue Wen, Ming Huang, Yizhou Liu, Xiaoxue Jiang, Tao Peng, Jun Wang, Xin Xia, Qingsong Li, Bin Li, Xin Liu, Tianlin |
| Affiliation | Southwest Petr Univ, Sch Geosci & Technol, Chengdu 610500, Sichuan, Peoples R China Southwest Petr Univ, State Key Lab Oil & Gas Reservoir Geol & Exploita, Chengdu 610500, Sichuan, Peoples R China Res Inst Petrol Explor & Dev, Beijing 100083, Peoples R China China Univ Petr, State Key Lab Petr Resources & Prospecting, Beijing 102249, Peoples R China China Univ Petr, Unconvent Nat Gas Inst, Beijing 102249, Peoples R China China Univ Geosci, Fac Earth Resources, Minist Educ, Key Lab Tecton & Petr Resources, Wuhan 430074, Hubei, Peoples R China China Univ Petr East China, Res Inst Unconvent Oil & Gas & Renewable Energy, Qingdao 266580, Shandong, Peoples R China Univ Utah, Energy & Geosci Inst, Salt Lake City, UT 84108 USA Curtin Univ, WA Sch Mines Minerals Energy & Chem Engn, Perth, WA 6845, Australia Univ Bristol, Sch Chem, Organ Geochem Unit, Bristol BS8 1TS, Avon, England Peking Univ, Sch Earth & Space Sci, Minist Educ, Key Lab Orogen Belt & Crustal Evolut, Beijing 100871, Peoples R China Peking Univ, Inst Oil & Gas, Beijing 100871, Peoples R China China Univ Petr, Unconvent Petr Collaborat Innovat Ctr, Beijing 102249, Peoples R China Southwest Petr Univ, Sch Geosci & Technol, Chengdu 610500, Sichuan, Peoples R China Southwest Petr Univ, State Key Lab Oil & Gas Reservoir Geol & Exploita, Chengdu 610500, Sichuan, Peoples R China Res Inst Petrol Explor & Dev, Beijing 100083, Peoples R China China Univ Petr, State Key Lab Petr Resources & Prospecting, Beijing 102249, Peoples R China China Univ Petr, Unconvent Nat Gas Inst, Beijing 102249, Peoples R China China Univ Geosci, Fac Earth Resources, Minist Educ, Key Lab Tecton & Petr Resources, Wuhan 430074, Hubei, Peoples R China China Univ Petr East China, Res Inst Unconvent Oil & Gas & Renewable Energy, Qingdao 266580, Shandong, Peoples R China Univ Utah, Energy & Geosci Inst, Salt Lake City, UT 84108 USA Curtin Univ, WA Sch Mines Minerals Energy & Chem Engn, Perth, WA 6845, Australia Univ Bristol, Sch Chem, Organ Geochem Unit, Bristol BS8 1TS, Avon, England Peking Univ, Sch Earth & Space Sci, Minist Educ, Key Lab Orogen Belt & Crustal Evolut, Beijing 100871, Peoples R China Peking Univ, Inst Oil & Gas, Beijing 100871, Peoples R China China Univ Petr, Unconvent Petr Collaborat Innovat Ctr, Beijing 102249, Peoples R China |
| Keywords | SOUTH CHINA EVIDENCE SICHUAN BASIN ORGANIC-MATTER MARINE SHALE ARGILLACEOUS DOLOMITE HYDROTHERMAL ACTIVITY QIONGZHUSI FORMATION LONGMAXI FORMATION GEOLOGICAL FACTORS PORE STRUCTURE |
| Issue Date | 1-Mar-2020 |
| Publisher | FUEL |
| Abstract | Marine shale gas exploration in southern China has successes and failures. Under the condition of great hydrocarbon generation material basis, shale gas wells drilled from some shale gas blocks are rich in methane, while the wells in other shale gas blocks with high nitrogen and low hydrocarbon gas, which indicates that they have different accumulation mechanisms. Therefore, the study of gas composition in shale will help us to figure out the mechanism of shale gas accumulation and loss. In this paper, the Lower Cambrian shale from Wei-201 well in Upper Yangtze Weiyuan Block and Jiangye-1 well from Lower Yangtze Xiuwu Basin are selected as research object, and shale samples are used for tests and experiments including analysis of gas composition and nitrogen isotope, test of porosity and TOC content, overburden permeability test, permeability test before and after methane adsorption under different osmotic pressure, permeability test parallel and vertical to the bedding surface, FIB-SEM (Focus Ion Beam Scanning Electron Microscope) and FIB-HIM (Focused Ion Beam Helium Ion Microscope). Finally, the reasons for the difference in the gas components of the Lower Cambrian shale gas in Weiyuan Block and Xiuwu Basin are studied by means of seismic interpretation, core description and outcrop observation besides the tests and experiments. The results show that the gas components of the Lower Cambrian shale in Weiyuan Block, the Upper Yangtze, mainly consist of methane, derived from liquid hydrocarbon cracking. The sealing capacity of roof and floor, the great self-sealing of shale and the flat anticline structure contribute to the high methane content in shale gas. The Lower Cambrian shale gas in Xiuwu Basin, the Lower Yangtze, is mostly nitrogen, which is derived both from atmosphere and deep crust-upper mantle. The detachment layer at the bottom of the Lower Cambrian, the widely developed deep faults and the Jurassic volcanic activity are the reasons for the high nitrogen and low hydrocarbon of shale gas. Based on the above analysis, the patterns are summarized for shale gas accumulation in the simple anticline background and reservoir destruction in the complex syncline background. |
| URI | http://hdl.handle.net/20.500.11897/585081 |
| ISSN | 0016-2361 |
| DOI | 10.1016/j.fuel.2019.115978 |
| Indexed | SCI(E) Scopus EI |
| Appears in Collections: | 地球与空间科学学院 造山带与地壳演化教育部重点实验室 |
