DOI: 10.1016/j.earscirev.2021.103674
论文题名: The Furongian to Lower Ordovician Alum Shale Formation in conventional and unconventional petroleum systems in the Baltic Basin – A review
作者: Schulz H.-M. ; Yang S. ; Schovsbo N.H. ; Rybacki E. ; Ghanizadeh A. ; Bernard S. ; Mahlstedt N. ; Krüger M. ; Amann-Hildebrandt A. ; Krooss B.M. ; Meier T. ; Reinicke A.
刊名: Earth Science Reviews
ISSN: 00128252
出版年: 2021
卷: 218 语种: 英语
中文关键词: Black shale
; Cambrian
; Ordovician
; Organic carbon
; Petroleum
; Uranium
英文关键词: black shale
; Cambrian
; carbonate
; Ordovician
; organic carbon
; petroleum hydrocarbon
; sandstone
; source rock
; uranium
; Baltic Region
; Embryophyta
英文摘要: The organic carbon- and uranium-rich, marine Alum Shale Formation in northwestern Europe (Middle Cambrian (Miaolingian) to Early Ordovician) was deposited in the Baltic Basin and surrounding areas. It is a proven source rock for conventional oil either in sandstones of Cambrian age or Ordovician and Silurian carbonates, and also contains a potential for shale oil and for biogenic or thermogenic shale gas. Despite the absence of higher land plant precursors, the primary Type II kerogen has an abnormally strong aromatic character at low thermal maturities due to α-particle bombardment by the elevated uranium content. The characteristic aromatic kerogen structure results in dead carbon formation and enhances hydrocarbon retention. As a consequence, effective petroleum expulsion is limited during maturation. The petroleum generation properties of the Alum Shale Formation changed over geological time due to the accumulated uranium irradiation. For thermally immature samples, high uranium content is positively correlated with high gas-oil ratios and the aromaticities of both the free hydrocarbons residing in the rock and the pyrolysis products from its kerogen. Such characteristics indicate that irradiation has had a strong influence on the overall organic matter composition and hence on the petroleum potential. At high uranium content, macromolecules are less alkylated than their less irradiated counterparts, and oxygen containing-compounds are enriched. However, the kerogen structure was less altered during catagenesis (420–340 Ma bp) than at present, and thus calibration is needed to predict petroleum generation in time and space. In southern central Sweden biogenic methane in the Alum Shale Formation was formed during oil degradation after the Quaternary glaciation following bitumen impregnation generated from local magmatic Carboniferous – Permian intrusions. Consequently, the Alum Shale Formation includes a mixed shale oil/biogenic gas play that resembles the formation of biogenic methane in the Antrim Shale (Michigan Basin, United States). In the Alum Shale Formation, low salinity pore water created a subsurface aqueous environment, which was favourable for microbes that have the potential to form biogenic methane. The ability to generate biogenic methane from samples of the Alum Shale Formation in incubation experiments still exists today. The permeability coefficients of highly mature Alum Shale Formation from Bornholm Island (southern Baltic Sea) cover a broad range from sub-nanodarcy to microdarcy, depending on fluid type (i.e. gas vs. liquid), (in-situ) fluid content, anisotropy, pore pressure and effective stress conditions. In general, the primary high total organic carbon content was not significantly reduced at overmature stages, consistently with the high sorption capacities. The Alum Shale Formation is thus an attractive gas shale candidate from the perspective of gas generation and retention. The strength of the overmature Alum Shale Formation on Bornholm, which is mainly determined by mineral composition, porosity and spatial distribution of the constituents, is relatively low compared to other well-studied shale formations. Based on brittleness estimates, the Alum Shale Formation may be regarded as an unconventional reservoir rock of medium quality from the mechanical point of view. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/166498
Appears in Collections: 气候变化与战略
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作者单位: Helmholtz Centre Potsdam–GFZ German Research Centre for Geosciences, Sec. 3.2 Organic Geochemistry, Potsdam, D-14473, Germany; China University of Petroleum (East China), Qingdao, China; Geological Survey of Denmark and Greenland (GEUS), Øster Voldgade 10, Copenhagen K, DK-1350, Denmark; Helmholtz Centre Potsdam–GFZ German Research Centre for Geosciences, Sec. 4.2 Geomechanics and Rheology, Potsdam, D-14473, Germany; Department of Geoscience, University of Calgary, 2500 University Dr. NW, Calgary, AB T2N 1N4, Canada; Muséum National d'Histoire Naturelle, Institut de Minéralogie, Physique des Matériaux et Cosmochimie, CNRS UMR 7590, Sorbonne Université, CNRS, Paris, F-75005, France; Department of Microbiology, Federal Institute for Geosciences and Natural Resources (BGR), Stilleweg 2, Hannover, D-30655, Germany; Institute of Geology and Geochemistry of Petroleum and Coal, RWTH Aachen University, Lochnerstrasse 4-20, Aachen, D-52056, Germany; geomecon GmbH, Reuchlinstr. 10, Berlin, D-10553, Germany; Nagra - Nationale Genossenschaft für die Lagerung radioaktiver Abfälle, Hardstrasse 73, Wettingen, CH-5430, Switzerland
Recommended Citation:
Schulz H.-M.,Yang S.,Schovsbo N.H.,et al. The Furongian to Lower Ordovician Alum Shale Formation in conventional and unconventional petroleum systems in the Baltic Basin – A review[J]. Earth Science Reviews,2021-01-01,218