Article ID Journal Published Year Pages File Type
4681658 Geoscience Frontiers 2013 8 Pages PDF
Abstract

The unconformity surface at the bottom of the Paleogene is one of the most important migration pathways in the Sikeshu Sag of the Junggar Basin, which consists of three layers: upper coarse clastic rock, lower weathering crust and leached zone. The upper coarse clastic rock is characterized by higher density and lower SDT and gamma-ray logging parameters, while the lower weathering crust displays opposite features. The transport coefficient of the unconformity surface is controlled by its position in respect to the basal sandstone; it is higher in the ramp region but lower in the adjacent uplifted and sag areas. The content of saturated hydrocarbons increases with the decrease of the content of non-hydrocarbons and asphaltenes. The content of benzo[c] carbazole decreases as the content of benzo[a] carbazole and [alkyl carbazole]/[alkyl + benzo carbazole] increases. This suggests that the unconformity surface is an efficient medium for the transportation of hydrocarbons.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The Paleogene Sikeshu unconformity surface consists of upper clastic, lower weathered and leached beds. ► The transport coefficient of the unconformity surface is higher at ramp and lower in uplift/sag. ► The unconformity surface provides efficient hydrocarbon transportation and accumulation.

Related Topics
Physical Sciences and Engineering Earth and Planetary Sciences Earth and Planetary Sciences (General)
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