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Methane-dominated gaseous inclusions in the Sinian carbonate reservoirs in central Sichuan Basin and their implications for natural gas accumulation (川中地区震旦系碳酸盐岩储层中的富甲烷气体包裹体及其对天然气成藏的指示)
  • 2024-01-08
元数据
名   称 Methane-dominated gaseous inclusions in the Sinian carbonate reservoirs in central Sichuan Basin and their implications for natural gas accumulation (川中地区震旦系碳酸盐岩储层中的富甲烷气体包裹体及其对天然气成藏的指示)
科技资源标识 CSTR:11738.14.NCDC.XDA14.PP5702.2024
DOI 10.1016/j.marpetgeo.2020.104871
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摘   要 The occurrence and genetic origins of gaseous inclusions in the Sinian carbonate reservoirs of Anyue gas field in
central Sichuan Basin were investigated with techniques of micro-Raman spectroscopy and microthermometry to
trace the oil and gas accumulation history. Three types of gaseous inclusions were identified in terms of their
compositions and the homogenization temperatures (Ths) of their coeval aqueous inclusions. Both type I and
type II gaseous inclusions are dominantly composed of methane with varying contents of pyrobitumen, indicating
their origins of type I and II precursor oil inclusions that have been thermally converted to the present
gaseous inclusions. The aqueous inclusions coeval with the present type I and type II gaseous inclusions have Th
values in the range of 120.3–136.9 ◦C and 140.8–168.5 ◦C, respectively, further confirming that they are derived
from precursor oil inclusions that were formed during 251–204 Ma and 202–169 Ma, respectively. For type III
gaseous inclusions, their gaseous components are also dominated by methane with minor CO2 and H2S, but no
detectable pyrobitumen is observed in them. This implies that they are not genetically related to any precursor
oil inclusions but were formed by direct trapping of gases in reservoirs when the paleo-oil pools have been
thermally converted to gas pools during the time of 153–103 Ma, which is consistent with the high Th values of
203.8–237.1 ◦C of their coeval aqueous inclusions.
The density of methane in gaseous inclusions was also estimated from methane Raman shifts. The respective
values of methane density for types I, II and III gaseous inclusions vary from 0.262 to 0.293 g/cm3 (avg. 0.272 g/
cm3), from 0.231 to 0.264 cm3/g (avg. 0.247 g/cm3), and from 0.231 to 0.293 cm3/g (avg. 0.249 g/cm3). Based
on the density of methane in type III gaseous inclusions and the Th values of their coeval aqueous inclusions,
their trapping pressures were calculated to be in the range of 93.3–134.1 MPa with formation pressure coefficients
of 1.32–1.79. This indicates that there were overpressures in the reservoirs during the oil to gas
cracking and that the almost hydrostatic system of the present Sinian gas pools is mostly related to the extensive
tectonic uplift and subsequent loss of natural gas since late Cretaceous.
学科分类
170.50
关键词
Natural gasFluid inclusionRaman spectrumOil crackingOverpressureSichuan basin
作者 Wang Xing
数据量 15.1 MiB
论文类型： journal
论文网址： https://doi.org/10.1016/j.marpetgeo.2020.104871
期刊名称： Marine and Petroleum Geology
出版时间： 2021-03-01
引用和标注
数据引用
Wang Xing. Methane-dominated gaseous inclusions in the Sinian carbonate reservoirs in central Sichuan Basin and their implications for natural gas accumulation (川中地区震旦系碳酸盐岩储层中的富甲烷气体包裹体及其对天然气成藏的指示). 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://cstr.cn/CSTR:11738.14.NCDC.XDA14.PP5702.2024.
Wang Xing. Methane-dominated gaseous inclusions in the Sinian carbonate reservoirs in central Sichuan Basin and their implications for natural gas accumulation (川中地区震旦系碳酸盐岩储层中的富甲烷气体包裹体及其对天然气成藏的指示). 国家冰川冻土沙漠科学数据中心(http://www.ncdc.ac.cn), 2024. https://www.doi.org/10.1016/j.marpetgeo.2020.104871.
许可协议
知识共享许可协议   本作品采用 知识共享署名 4.0 国际许可协议进行许可。
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