Geological mapping,interpreted cross sections,structural analyses and residual thickness maps were used to characterize the evolution of stress setting,structure and stratigraphic distribution of the Chepaizi Uplift,w...Geological mapping,interpreted cross sections,structural analyses and residual thickness maps were used to characterize the evolution of stress setting,structure and stratigraphic distribution of the Chepaizi Uplift,which is a NW-SE trending structure located in the Western Junggar Basin.The NS-trending faults show an important transpressional phase during the Late Permian,as demonstrated by tectonic stress field and stratigraphic thickness variations.A major compressional thrusting and strike-slip phase during the Late Jurassic created a series of NW-SE faults that originated by the large-scale uplift event in the Northern Tianshan.Faults were reactivated as thrust and dextral strike-slip faults.In addition,the angular unconformity observed between Jurassic and Cretaceous provide evidence of this tectonic event.Lots of normal faults indicate that the area records southward tilting and regional derived extensional stress that took place during the Neogene.Before that,thick Early Cenozoic strata are widely deposited.The balanced cross-section highlights the evolution of stress setting and stratigraphic distribution of the Chepaizi Uplift.展开更多
Geochemical composition characteristics of light oils from the Tertiary in the west of the Chepaizi uplift in the Junggar basin, northwest China, are distinct from those of biodegraded oils derived from the Permian in...Geochemical composition characteristics of light oils from the Tertiary in the west of the Chepaizi uplift in the Junggar basin, northwest China, are distinct from those of biodegraded oils derived from the Permian in the study area and crude oils from some adjacent oil fields such as the Chepaizi and Xiaoguai oilfields. Oil source corre-lation shows that light oils in the study area have similar n-alkane and isoprenoid distribution patterns and carbon isotope compositions with the coal-derived oils from the Jurassic, and display obvious discrepancy on biomarker composition characteristics with the Cretaceous source rock extracts, inferring that they are probably the mixed oils from the Jurassic coal measures and Cretaceous source rocks. In this study, combined with the geochemical data of coal-derived oils from the Jurassic and Cretaceous source rocks or crude oils from the Cretaceous, the source and commingling features of the Tertiary crude oils of Well Pai 2 and Well Pai 8 were investigated. The proportion of the two sources in the mixed crude oils was estimated, and the hydrocarbon accumulation pattern of reservoirs in the study area was established.展开更多
基金financially supported by the Natural Sciences Foundation of China(Chen S.,grant number 41502208)Science Foundation of China University of Petroleum(Chen S.,grant number 2462017BJB01)CNPC Innovation Foundation(Chen S.,grant number 2017D-5007-0103)
文摘Geological mapping,interpreted cross sections,structural analyses and residual thickness maps were used to characterize the evolution of stress setting,structure and stratigraphic distribution of the Chepaizi Uplift,which is a NW-SE trending structure located in the Western Junggar Basin.The NS-trending faults show an important transpressional phase during the Late Permian,as demonstrated by tectonic stress field and stratigraphic thickness variations.A major compressional thrusting and strike-slip phase during the Late Jurassic created a series of NW-SE faults that originated by the large-scale uplift event in the Northern Tianshan.Faults were reactivated as thrust and dextral strike-slip faults.In addition,the angular unconformity observed between Jurassic and Cretaceous provide evidence of this tectonic event.Lots of normal faults indicate that the area records southward tilting and regional derived extensional stress that took place during the Neogene.Before that,thick Early Cenozoic strata are widely deposited.The balanced cross-section highlights the evolution of stress setting and stratigraphic distribution of the Chepaizi Uplift.
基金supported by the National Basic Research Program of China (2006CB202300)
文摘Geochemical composition characteristics of light oils from the Tertiary in the west of the Chepaizi uplift in the Junggar basin, northwest China, are distinct from those of biodegraded oils derived from the Permian in the study area and crude oils from some adjacent oil fields such as the Chepaizi and Xiaoguai oilfields. Oil source corre-lation shows that light oils in the study area have similar n-alkane and isoprenoid distribution patterns and carbon isotope compositions with the coal-derived oils from the Jurassic, and display obvious discrepancy on biomarker composition characteristics with the Cretaceous source rock extracts, inferring that they are probably the mixed oils from the Jurassic coal measures and Cretaceous source rocks. In this study, combined with the geochemical data of coal-derived oils from the Jurassic and Cretaceous source rocks or crude oils from the Cretaceous, the source and commingling features of the Tertiary crude oils of Well Pai 2 and Well Pai 8 were investigated. The proportion of the two sources in the mixed crude oils was estimated, and the hydrocarbon accumulation pattern of reservoirs in the study area was established.
