Geological and geochemical conditions for the formation of the oil composition in the deposits of the Permian and Jurassic oil and gas complexes in the Fukang depression (Junggar basin)
| Autor: | Houqiang Yang, Elena Soboleva |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2021 |
| Předmět: |
Permian
Geochemistry Structural basin geological and geochemical conditions 010502 geochemistry & geophysics 01 natural sciences 03 medical and health sciences Depression (economics) deposits formation 030304 developmental biology 0105 earth and related environmental sciences source rocks 0303 health sciences QE1-996.5 business.industry Fossil fuel generation potential biomarkers Geology hydrocarbon fluids junggar oil and gas basin Geophysics sedimentation conditions molecular composition rock-eval pyrolysis Composition (visual arts) business fukang depression |
| Zdroj: | Georesursy, Vol 23, Iss 2, Pp 110-119 (2021) |
| ISSN: | 1608-5078 1608-5043 |
| Popis: | Within the eastern part of the Fukang depression, the main productive series are confined to the Permian and Jurassic oil and gas complexes (OGC), in which the Middle Permian and Lower-Middle Jurassic oil and gas source rocks (OGSRs) are distinguished. The article discusses in detail the oil and gas source characteristics of the Middle Permian and Lower-Middle Jurassic rocks, the molecular composition of oils and bitumoids from the OGSRs, and also interprets the characteristics of the biomarkers in them from the standpoint of the sedimentary-migration theory of oil generation. An attempt is made to explain the reasons for the difference in the properties and composition of oils from different OGCs. It is shown that the composition of hydrocarbon fluids of deposits is determined not only by the geological and geochemical conditions of sedimentation of oil and gas source deposits, but also associated with migration processes and subsequent secondary changes in the accumulation. In terms of composition, three groups of oils were identified: Permian and Jurassic heavy oils with a light carbon isotopic composition and the presence of β-carotene and gammacerane, they underwent different degrees of biodegradation, which depended on the geological conditions of the deposits; Permian medium oils in density (0.84 and 0.87 g/cm3), the composition of biomarkers of which is very close to that of the first group, and Jurassic light oils with a high content of solid paraffins and a heavier carbon isotopic composition, almost do not contain β-carotene and gammacerane concentrations are low. |
| Databáze: | OpenAIRE |
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