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
【目的】车排子凸起中生界稠油资源丰富,但原油生物降解严重,制约了勘探进程。【方法】为明确车排子凸起东翼中生界原油的生物降解程度,对车排子凸起东翼侏罗纪和白垩纪储层样品抽提出的饱和烃和芳香烃进行了气相色谱—质谱(GC-MS)分析...【目的】车排子凸起中生界稠油资源丰富,但原油生物降解严重,制约了勘探进程。【方法】为明确车排子凸起东翼中生界原油的生物降解程度,对车排子凸起东翼侏罗纪和白垩纪储层样品抽提出的饱和烃和芳香烃进行了气相色谱—质谱(GC-MS)分析,采用分子地球化学指标,对其进行定性与定量评价。【结果】通过聚类分析,将原油分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四类族群。PM(Peters and Moldowan)法分析结果表明Ⅰ_(1)类和Ⅱ_(1)类原油的生物降解程度达PM7,Ⅰ_(2)类和Ⅳ类原油的生物降解程度为PM8;Ⅱ_(2)类和Ⅲ_(1)类原油的生物降解程度为PM9,Ⅲ_(2)类原油生物降解程度为PM9+。基于优化的Manco法求得的MN_(1)值介于19693~215623,Ⅰ类原油的MN_(2)值介于769~919,Ⅱ类原油的MN_(2)值介于768~907,Ⅲ类原油的MN_(2)值介于906~954,Ⅳ类原油的MN_(2)值介于774~817。同一原油族群的Manco数与原油密度、黏度、非烃和沥青质含量均呈现良好的正相关性,与总烃呈现良好的负相关性。优化的Manco法成功厘定了生物降解程度在PM7-PM9+的储层样品,与PM等级评价具有一致性。【结论】与PM法相比,优化的Manco法对原油生物降解的识别分辨率更高。通过PM法定性评价和优化Manco法定量评价相结合,可以很好地揭示原油物性的变化,对稠油区的油气勘探有重要的指导作用。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.
文摘【目的】车排子凸起中生界稠油资源丰富,但原油生物降解严重,制约了勘探进程。【方法】为明确车排子凸起东翼中生界原油的生物降解程度,对车排子凸起东翼侏罗纪和白垩纪储层样品抽提出的饱和烃和芳香烃进行了气相色谱—质谱(GC-MS)分析,采用分子地球化学指标,对其进行定性与定量评价。【结果】通过聚类分析,将原油分为Ⅰ、Ⅱ、Ⅲ、Ⅳ四类族群。PM(Peters and Moldowan)法分析结果表明Ⅰ_(1)类和Ⅱ_(1)类原油的生物降解程度达PM7,Ⅰ_(2)类和Ⅳ类原油的生物降解程度为PM8;Ⅱ_(2)类和Ⅲ_(1)类原油的生物降解程度为PM9,Ⅲ_(2)类原油生物降解程度为PM9+。基于优化的Manco法求得的MN_(1)值介于19693~215623,Ⅰ类原油的MN_(2)值介于769~919,Ⅱ类原油的MN_(2)值介于768~907,Ⅲ类原油的MN_(2)值介于906~954,Ⅳ类原油的MN_(2)值介于774~817。同一原油族群的Manco数与原油密度、黏度、非烃和沥青质含量均呈现良好的正相关性,与总烃呈现良好的负相关性。优化的Manco法成功厘定了生物降解程度在PM7-PM9+的储层样品,与PM等级评价具有一致性。【结论】与PM法相比,优化的Manco法对原油生物降解的识别分辨率更高。通过PM法定性评价和优化Manco法定量评价相结合,可以很好地揭示原油物性的变化,对稠油区的油气勘探有重要的指导作用。
