DOI: 10.1007/s00531-014-1063-0
Scopus记录号: 2-s2.0-84939897867
论文题名: Molecular and isotopic compositions and origin of natural gases from Cambrian and Carboniferous-Lower Permian reservoirs of the onshore Polish Baltic region
作者: Kotarba M.J. ; Nagao K.
刊名: International Journal of Earth Sciences
ISSN: 14373254
出版年: 2014
卷: 104, 期: 1 起始页码: 241
结束页码: 261
语种: 英语
英文关键词: Carbon dioxide
; Hydrocarbon gases
; Molecular nitrogen
; Noble gases
; Origin of natural gases
; Stable isotopes
英文摘要: Natural gases from Middle Cambrian and Carboniferous-Lower Permian reservoirs of the onshore Polish Baltic region were studied for their molecular and stable isotope compositions. The following gas species were analysed: 12,13C in CH4 , C2 H6 , C3 H8 , n-C4 H10 , i-C4 H10 and CO2 , 1,2H in CH4 , 14,15N in N2 , and stable isotopes of all noble gases. Due to significantly different geological settings and genetic types of source rocks of Eastern and Western Pomerania, the molecular and isotopic compositions of natural gases of these two regions exhibit distinct differences. Hydrocarbon gases associated with oil accumulated in the Middle Cambrian reservoir of Eastern Pomerania were generated during low-temperature thermogenic processes from a single source rock containing Type-II kerogen at one phase of petroleum generation. Non-associated hydrocarbon gases accumulated in the Carboniferous (Mississippian and Pennsylvanian)-Lower Permian (Rotliegend) reservoirs of Western Pomerania originated during at least two phases of gas generation by thermogenic processes from mainly Type-III kerogen and a small component of mixed Type-III/II kerogen. Noble gases are in general heavily enriched in radiogenic and nucleogenic isotopes such as 4He, 40Ar and 21Ne accumulated in the reservoirs. Weak contributions of mantle-derived He and Ne are observed. Radiogenic 4He/40Ar ratios are higher than the average production rate ratio of about 5 for radiogenic 4He/40Ar in crustal materials, which might have been caused by a selective supply of 4He that is lighter than 40Ar from crustal rocks, or (U + Th)/K ratio might be higher than the average in crustal block. Carbon dioxide from gases of both the Western and Eastern Pomerania were mainly generated during thermogenic processes of transformation of organic matter, although gases of Western Pomerania can contain an endogenic component. Molecular nitrogen from the Eastern Pomeranian natural gases was mainly generated during low-temperature thermal transformation of organic matter and derived from NH3 and NH4 of crustal fluid, whereas molecular nitrogen from Western Pomeranian natural gases contains a significant component from the destruction of organic matter at a higher maturity level which may have been caused by a high heat flux from the volcanic activity during late Pennsylvanian–early Rotliegend ages, and has a bigger component release from NH4 -rich illites. © 2014, The Author(s). URL: https://www.scopus.com/inward/record.uri?eid=2-s2.0-84939897867&doi=10.1007%2fs00531-014-1063-0&partnerID=40&md5=cde0f57d1e63edd4c2c7150e53c507ef
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/70363
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Faculty of Geology, Geophysics and Environmental Protection, AGH University of Science and Technology, Al. Mickiewicza 30, Kraków, Poland; Geochemical Research Center, Graduate School of Science, University of Tokyo, Hongo, Bunkyo-ku, Tokyo, Japan
Recommended Citation:
Kotarba M.J.,Nagao K.. Molecular and isotopic compositions and origin of natural gases from Cambrian and Carboniferous-Lower Permian reservoirs of the onshore Polish Baltic region[J]. International Journal of Earth Sciences,2014-01-01,104(1)