Through oil-oil and oil-source correlation and combined with the comprehensive study of hydrocarbon generation and accumulation history, the oil sources of typical reservoirs of different geologic periods in the hinte...Through oil-oil and oil-source correlation and combined with the comprehensive study of hydrocarbon generation and accumulation history, the oil sources of typical reservoirs of different geologic periods in the hinterland of the Junggar basin are revealed. It is concluded that the crude oils in the study area can be classified into four types： The oil in the area of well Zhuang-1 and well Sha-1 belongs to type-I, which was generated from Cretaceous to Paleogene （K-E） and its source rocks are distributed in the Fengcheng formation of the Permian in the western depression to the well Pen-1. The oil in the area of well Yong-6 （K1 tg） belongs to type-Ⅱ, which was generated from Cretaceous to Paleogene and its source rocks are distributed in the Wuerhe formation of the Permian in the Changji depression. The oil in the area of well Yong-6 （J2x） belongs to type-III, which was generated at the end of the Paleogene and its source rocks are distributed in the coal measures of the Jurassic in the Changji depression. The oil of well Zheng-1 and well Yong-1 belongs to type-IV, which was generated in the Paleogene, and its source rocks are distributed in the Wuerhe formation of the Lower Permian and coal measures of the Jurassic. It is indicated that the hydrocarbon accumulation history in the study area was controlled by the tectonic evolution history of the Che-Mo palaeohigh and the hydrocarbon generation history of well Pen-1 in the western depression and Changji depression.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
Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements...Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1)carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2)carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formation of them;and(3)carbon and oxygen ions in the carbonate cements migrate from the underlying overpressured system.This suggests that the occurrence of carbonate cemented zones in this region results from multiple phases of organic fluid expulsion out of the overpressure compartment through geological time.This study provides a plausible mechanism of the formation of carbonate cemented zones adjacent to the top overpressured surface in the clastic sedimentary basins,and has an important implication for understanding the internal correlation between the formation of carbonate cemented zones adjacent to top overpressured surface and geofluids expulsion out of overpressured system.展开更多
文摘Through oil-oil and oil-source correlation and combined with the comprehensive study of hydrocarbon generation and accumulation history, the oil sources of typical reservoirs of different geologic periods in the hinterland of the Junggar basin are revealed. It is concluded that the crude oils in the study area can be classified into four types： The oil in the area of well Zhuang-1 and well Sha-1 belongs to type-I, which was generated from Cretaceous to Paleogene （K-E） and its source rocks are distributed in the Fengcheng formation of the Permian in the western depression to the well Pen-1. The oil in the area of well Yong-6 （K1 tg） belongs to type-Ⅱ, which was generated from Cretaceous to Paleogene and its source rocks are distributed in the Wuerhe formation of the Permian in the Changji depression. The oil in the area of well Yong-6 （J2x） belongs to type-III, which was generated at the end of the Paleogene and its source rocks are distributed in the coal measures of the Jurassic in the Changji depression. The oil of well Zheng-1 and well Yong-1 belongs to type-IV, which was generated in the Paleogene, and its source rocks are distributed in the Wuerhe formation of the Lower Permian and coal measures of the Jurassic. It is indicated that the hydrocarbon accumulation history in the study area was controlled by the tectonic evolution history of the Che-Mo palaeohigh and the hydrocarbon generation history of well Pen-1 in the western depression and Changji depression.
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.
基金supported by the Important National Science&Technology Specific Projects(Grant No.2008ZX05001)Scientific Development Projects of Petrochina Company Limited(Grant No.2008B-0100)+2 种基金the Doctoral Education Program Fund of Ministry of Education,China(Grant No.20060491505)American Association of Petroleum Geologists Grants-in-Aid Foundation ProgramNational Natural Science Foundation of China(Grant Nos.40739904,40902039)
文摘Carbonate cemented zones are normally adjacent to the top overpressured surface in the central Junggar Basin,NW China.Stable carbon and oxygen isotopic compositions and petrological investigations of carbonate cements in the carbonate cemented zones indicate that:(1)carbonate cements are composed dominantly of ferrocalcite,ferroan dolomite,and ankerite;(2)carbonate cements are formed under a high temperature circumstance in the subsurface,and organic fluid migration has an important effect on the formation of them;and(3)carbon and oxygen ions in the carbonate cements migrate from the underlying overpressured system.This suggests that the occurrence of carbonate cemented zones in this region results from multiple phases of organic fluid expulsion out of the overpressure compartment through geological time.This study provides a plausible mechanism of the formation of carbonate cemented zones adjacent to the top overpressured surface in the clastic sedimentary basins,and has an important implication for understanding the internal correlation between the formation of carbonate cemented zones adjacent to top overpressured surface and geofluids expulsion out of overpressured system.
