The Bodong Sag,located in the Bohai Sea,offshore China,is one of the most petroliferous basins in China.Based on three dimensional seismic reflection data and time slice data,we analyze the fault system of the Bodong ...The Bodong Sag,located in the Bohai Sea,offshore China,is one of the most petroliferous basins in China.Based on three dimensional seismic reflection data and time slice data,we analyze the fault system of the Bodong area in detail,establish the fault structure pattern of different types and summarize the distribution of the fault system.It is concluded that the development characteristics of the Cenozoic fault system are in accordance with the dextral stress field of the Tanlu Fault,which displayed a brush structure with NNE strike-slip faults as its principal faults,NE-trending extensional faults as secondary faults and EW-trending faults as minor faults.Faults can be divided into （1） strike-slip type,（2） extensional type,（3） strike-slip extensional type and （4） extensional strike-slip type.The spatial structures of different faults have obvious differences because of the fault properties and activity intensity.The fault system at different stages shows tremendous differences because of the transition of the Tanlu Fault from sinistral strike-slip to dextral strike-slip,the transition between extension and strike-slip,and the transition from mantle upwelling to thermal subsidence.According to the controlling effect of faults on basin structure,the Cenozoic basin experienced four evolutionary stages,（a） transition stage from sinistral strike-slip to dextral strike-slip,（b） strike-slip extensional faulted stage,（c） extensional strike-slip faulted stage and （d） strike-slip depression stage.The identification of temporal and spatial differences of faults could be used as a significant guideline for oil and gas exploration in the Bodong area.展开更多
The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulat...The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulation system, accumulation assemblage and reservoir. This paper discusses the characteristics of hydrocarbon accumulation system assemblages of the Zhanhua Depression, which include four kinds of genetic patterns： （1） buried-hill hydrocarbon accumulation system assemblage; （2） self-sourced accumulation system assemblage from the upper interval of member 4 to member 1 of Shahejie formation; （3） transition accumulation system assemblage from member 1 of the Shahejie formation to Dongying formation and （4） externally sourccd accumulation system assemblage in the late Tertiary. The hydrocarbon-source transport network layer consisted of faults and unconformities, which connected with the reservoir layer.展开更多
Based on seismic and drilling data in the study area,the geological structure and kinematic process of the Termit rift basin were studied using seismic profile interpretation and balanced restoration to find out the d...Based on seismic and drilling data in the study area,the geological structure and kinematic process of the Termit rift basin were studied using seismic profile interpretation and balanced restoration to find out the dynamic mechanism of the basin.(1)The geological structure of the Termit Basin is represented as a narrow rift basin,with development of series of structural styles in extensional,extensional strike-slip and compressional stress setting.On plane,it is narrow in the north and wide in the south,and transitions from graben to half-graben from north to south;it features a graben controlled by the boundary faults in the north and a fault-overlapped half-graben in the south.(2)Before the Cretaceous,a series of hidden faults developed in the West African rift system,which laid the foundation for the development location and distribution direction of the Termit Basin;during the Cretaceous to Paleogene periods,the basin experienced two phases of rifting in Early Cretaceous and Paleogene,which controlled the initial structure and current structural shape of the basin respectively;during the Neogene to Quaternary,the basin was subjected to weak transformation.(3)In the Precambrian,the Pan-African movement gave rise to a narrow and long weak zone within the African plate,which provided the pre-existing structural conditions for the formation of the Termit Basin.In the Early Cretaceous,affected by the South Atlantic rifting,the Pan African weak zone was reactivated,resulting in the first stage of rifting and the basic structural framework of the Termit Basin.In the Paleogene,affected by the subduction and convergence of the Neo-Tethys Ocean,the African-Arabian plate extended in near E-W trending,and the Termit Basin experienced the second stage of rifting.The oblique extension in this period caused intense structural differentiation,and the current structural pattern of alternate uplifts and depressions took shape gradually.展开更多
Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The s...Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.展开更多
文摘The Bodong Sag,located in the Bohai Sea,offshore China,is one of the most petroliferous basins in China.Based on three dimensional seismic reflection data and time slice data,we analyze the fault system of the Bodong area in detail,establish the fault structure pattern of different types and summarize the distribution of the fault system.It is concluded that the development characteristics of the Cenozoic fault system are in accordance with the dextral stress field of the Tanlu Fault,which displayed a brush structure with NNE strike-slip faults as its principal faults,NE-trending extensional faults as secondary faults and EW-trending faults as minor faults.Faults can be divided into （1） strike-slip type,（2） extensional type,（3） strike-slip extensional type and （4） extensional strike-slip type.The spatial structures of different faults have obvious differences because of the fault properties and activity intensity.The fault system at different stages shows tremendous differences because of the transition of the Tanlu Fault from sinistral strike-slip to dextral strike-slip,the transition between extension and strike-slip,and the transition from mantle upwelling to thermal subsidence.According to the controlling effect of faults on basin structure,the Cenozoic basin experienced four evolutionary stages,（a） transition stage from sinistral strike-slip to dextral strike-slip,（b） strike-slip extensional faulted stage,（c） extensional strike-slip faulted stage and （d） strike-slip depression stage.The identification of temporal and spatial differences of faults could be used as a significant guideline for oil and gas exploration in the Bodong area.
文摘The concept of the three-layer structure of continental basins is presented based on the characteristics of layered structure of basins. The reservoir could be classified into accumulation system assemblage, accumulation system, accumulation assemblage and reservoir. This paper discusses the characteristics of hydrocarbon accumulation system assemblages of the Zhanhua Depression, which include four kinds of genetic patterns： （1） buried-hill hydrocarbon accumulation system assemblage; （2） self-sourced accumulation system assemblage from the upper interval of member 4 to member 1 of Shahejie formation; （3） transition accumulation system assemblage from member 1 of the Shahejie formation to Dongying formation and （4） externally sourccd accumulation system assemblage in the late Tertiary. The hydrocarbon-source transport network layer consisted of faults and unconformities, which connected with the reservoir layer.
基金Supported by the National Natural Science Foundation of China Enterprise Innovation and Development Joint Fund Project(U19B6003-01)Scientific research and technology development project of China National Petroleum Corporation(2021DJ3103).
文摘Based on seismic and drilling data in the study area,the geological structure and kinematic process of the Termit rift basin were studied using seismic profile interpretation and balanced restoration to find out the dynamic mechanism of the basin.(1)The geological structure of the Termit Basin is represented as a narrow rift basin,with development of series of structural styles in extensional,extensional strike-slip and compressional stress setting.On plane,it is narrow in the north and wide in the south,and transitions from graben to half-graben from north to south;it features a graben controlled by the boundary faults in the north and a fault-overlapped half-graben in the south.(2)Before the Cretaceous,a series of hidden faults developed in the West African rift system,which laid the foundation for the development location and distribution direction of the Termit Basin;during the Cretaceous to Paleogene periods,the basin experienced two phases of rifting in Early Cretaceous and Paleogene,which controlled the initial structure and current structural shape of the basin respectively;during the Neogene to Quaternary,the basin was subjected to weak transformation.(3)In the Precambrian,the Pan-African movement gave rise to a narrow and long weak zone within the African plate,which provided the pre-existing structural conditions for the formation of the Termit Basin.In the Early Cretaceous,affected by the South Atlantic rifting,the Pan African weak zone was reactivated,resulting in the first stage of rifting and the basic structural framework of the Termit Basin.In the Paleogene,affected by the subduction and convergence of the Neo-Tethys Ocean,the African-Arabian plate extended in near E-W trending,and the Termit Basin experienced the second stage of rifting.The oblique extension in this period caused intense structural differentiation,and the current structural pattern of alternate uplifts and depressions took shape gradually.
文摘Based on first-hand material from the geological exploration of petroleum,we made a detailed study of the tectonic development in the Early Cretaceous and the distribution of basement rifts in the Songliao Basin.The sedimentary characteristics of this epoch and the tectono-paleogeography of the basin were expounded.The results show that in its early stages,the Songliao Basin was characterized by a detached faulted basin in which mainly lake facies developed among mountains.It became gradually one lake during the late stages of the Early Cretaceous.During this period,the fault activity in the Songliao Basin changed from a turbulent to a quiet development,the water area from small separated lakes to one large lake,in which the sedimentary facies were divided into asymmetric eastern and western parts.In the basin a volcanic clastic rock-alluvial fan system developed and a fan delta-lake-small delta-river system was mainly deposired.Our research also shows that the basement rifts not only controlled the distribution of fault depressions and the tectonic development in the Early Cretaceous,but had also an effect on the orientation of sedimentation,source area and river system,which determine the tectonopaleogeography of the Early Cretaceous.
