A number of isolated fault sags in Late Jurassic--Early Cretaceous were developed in the early stage of southern Songliao Basin,and unified to a depression basin in the late stage.Therefore,multiple isolated lower pet...A number of isolated fault sags in Late Jurassic--Early Cretaceous were developed in the early stage of southern Songliao Basin,and unified to a depression basin in the late stage.Therefore,multiple isolated lower petroliferous systems were formed with fault sags as source rocks.The source rocks of fault sags in Late Jurassic--Early Cretaceous were mainly described with gas generation as favorable source rocks,leading to the southern Songliao Basin rich in natural gas resources combined with organic gas resources in Nenjiang Formation.A number of tectonic movements in southern Songliao Basin led to the formation of abundant structural traps and complex fault systems,and controlled the distribution strata and positions of sources rocks in Late Jurassic--Early Cretaceous fault sags.The oil-gas reservoirs can be divided into two types,i.e.,primary and secondary ones.The primary oil-gas reservoirs were distributed in the fault sag strata and the bottom of overlying depression strata(lower Quan-1 Member).The oil-gas reservoir accumulation depended on the trap development situation and the distance from source rocks.The preservation conditions of oil-gas reservoirs depended on the degree of reconstruction in the late tectonism.The secondary oil-gas reservoirs were distribution in the Quantou Formation of depression strata,where oil and gas reservoir accumulation depended on three conditions,i.e.,trap development situation,deep gas sources and the fault to connect the shallow traps and deep gas sources.The southern Songliao Basin is rich in lower coal type gas,upper oil-gas and biogas resources,which are important resources in the future.展开更多
Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by L...Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by LREE-enrichment. By analysis of the discriminant index of the sedimentary environment,the tectonic setting of Zhesi Formation is determined to be a continental island arc environment. Meanwhile,according to the sedimentary structure and lithology combination,Zhesi Formation is divided into the neritic-bathyal retention-reduction environment as well as the delta front and prodelta sedimentary systems.展开更多
According to the lithological assemblages and elemental geochemistry of the measured profile,the authors studied the sedimentary and tectonic environment of the Late Carboniferous Tangjiatun Formation in Acheng. The r...According to the lithological assemblages and elemental geochemistry of the measured profile,the authors studied the sedimentary and tectonic environment of the Late Carboniferous Tangjiatun Formation in Acheng. The results show that the trace elements of mudstone samples from Tangjiatun Formation have the characteristics of high Th,V and Cu,but low Ba,Nb and Sr. The rare earth elements are characterized by significantly light and heavy rare earth elements differentiation,relative enrichment of light rare earth elements,and a negative anomaly of δEu. The Tangjiatun Formation belongs to a marine and delta sedimentary environment,and its tectonic setting is considered as a continental island arc environment.展开更多
文摘A number of isolated fault sags in Late Jurassic--Early Cretaceous were developed in the early stage of southern Songliao Basin,and unified to a depression basin in the late stage.Therefore,multiple isolated lower petroliferous systems were formed with fault sags as source rocks.The source rocks of fault sags in Late Jurassic--Early Cretaceous were mainly described with gas generation as favorable source rocks,leading to the southern Songliao Basin rich in natural gas resources combined with organic gas resources in Nenjiang Formation.A number of tectonic movements in southern Songliao Basin led to the formation of abundant structural traps and complex fault systems,and controlled the distribution strata and positions of sources rocks in Late Jurassic--Early Cretaceous fault sags.The oil-gas reservoirs can be divided into two types,i.e.,primary and secondary ones.The primary oil-gas reservoirs were distributed in the fault sag strata and the bottom of overlying depression strata(lower Quan-1 Member).The oil-gas reservoir accumulation depended on the trap development situation and the distance from source rocks.The preservation conditions of oil-gas reservoirs depended on the degree of reconstruction in the late tectonism.The secondary oil-gas reservoirs were distribution in the Quantou Formation of depression strata,where oil and gas reservoir accumulation depended on three conditions,i.e.,trap development situation,deep gas sources and the fault to connect the shallow traps and deep gas sources.The southern Songliao Basin is rich in lower coal type gas,upper oil-gas and biogas resources,which are important resources in the future.
文摘Through a sampling analysis of trace elements and REE in the section of Middle Permian Zhesi Formation in Solon area of Inner Mongolia,it is found that the overall sandstone and mudstone samples are characterized by LREE-enrichment. By analysis of the discriminant index of the sedimentary environment,the tectonic setting of Zhesi Formation is determined to be a continental island arc environment. Meanwhile,according to the sedimentary structure and lithology combination,Zhesi Formation is divided into the neritic-bathyal retention-reduction environment as well as the delta front and prodelta sedimentary systems.
文摘According to the lithological assemblages and elemental geochemistry of the measured profile,the authors studied the sedimentary and tectonic environment of the Late Carboniferous Tangjiatun Formation in Acheng. The results show that the trace elements of mudstone samples from Tangjiatun Formation have the characteristics of high Th,V and Cu,but low Ba,Nb and Sr. The rare earth elements are characterized by significantly light and heavy rare earth elements differentiation,relative enrichment of light rare earth elements,and a negative anomaly of δEu. The Tangjiatun Formation belongs to a marine and delta sedimentary environment,and its tectonic setting is considered as a continental island arc environment.
