In order to investigate pore characteristics and formation mechanism in the high-maturity organic-rich shale of Lower Cambrian Jiumenchong Formation in southern Guizhou,the pore structure,pore type and storage propert...In order to investigate pore characteristics and formation mechanism in the high-maturity organic-rich shale of Lower Cambrian Jiumenchong Formation in southern Guizhou,the pore structure,pore type and storage properties are well studied through the rock thin section,total rock X-ray diffraction,lowtemperature nitrogen adsorption,high pressure mercury injection-adsorption test,helium porosity test,argon ion polishing-scanning electron microscope,thermal evolution and pore evolution history reconstruction,and based on the diagenesis and compaction as well as thermal evolution process,a microscopic pore formation and evolution model of high-maturity organic-rich shale are established.The result shows that the high-maturity organic-rich shale of Jiumenchong Formation has the average total specific surface area of 12.66m^(2)/g and the total pore volume of 11.54×10^(-3)cm^(3)/g,and the total specific surface area have a positive correlation with total pore volume;the total specific surface area and the total pore volume are slightly lower compared with the Lower Silurian shale.The pores are dominated by micropores and mesopores,while macropores are very rare.The pores of the organic-rich shale mainly are organic pores with small diameter usually less than 30 nm,and the pore boundary form is irregular,the inorganic mineral pores are not developed.Compared with the Silurian shale,the shale has poorer reservoir property,the average porosity is only 2.80%;the horizontal permeability is 1e3 times of the vertical permeability,indicating the horizontal lamellations are not developed.The formation and evolution of pores in high-maturity organic-rich shale is jointly influenced by the evolutionary process of intergranular pores of inorganic mineral under the control of the diagenesis and compaction,the organic pore formation process in the hydrocarbon generation-oil formation-oil and gas transformation sequence under the control of thermal evolution,and the natural gas loss-supply equilibration process under the condition of later pore preservation.展开更多
A huge coral reef occurring in the Triticites belt of the Maping Formation, in Bianping Village, about 4 km west of Houchang Town from Ziyun County, Southern Guizhou, China is described. The coral reef has been well s...A huge coral reef occurring in the Triticites belt of the Maping Formation, in Bianping Village, about 4 km west of Houchang Town from Ziyun County, Southern Guizhou, China is described. The coral reef has been well studied and some significant characteristics were dis-covered: the composition of reef-building community is very monotonous; there are only one or two builders in each reef-building stage; the dwellers are also poor in variety; the reef-building process is very simple; the reef has been separately built by various reef-building mechanisms, and there have been few parts built by two coexisting building mechanisms; the process of reef building is often discontinuous and lacks transition. All these characteristics are considered to be unique to the recovery stage of reef communities after F/F event and are representative of a process that reef communities must undergo post the catastrophe.展开更多
This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates a...This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates are controlled by ancient sea-level changes. It is particularly so if the supply of detrital materials was low, when the magnetic susceptibility was mainly controlled by the content of authigenic minerals. If the supply of detrital materials was high, the average susceptibility value would be higher, but there is still a correlation between susceptibility and sea-level curves. A sea level rise would lead to a decrease in the content of the detrital materials, and therefore to a decrease in the susceptibility values. On the top of HST, the uplift and exposure events may lead to elevated magnetic susceptibility values. Carbonate susceptibilities can therefore be considered as one of the environmental proxy data for the research of sequence stratigraphy.展开更多
The Permian in slope facies area of southern Guizhou consists of 16 third order sequences, which can be grouped as four sequence sets and further into two mesosequences. Most of them are delineated by conformable or s...The Permian in slope facies area of southern Guizhou consists of 16 third order sequences, which can be grouped as four sequence sets and further into two mesosequences. Most of them are delineated by conformable or submarine erosion surfaces, and well controlled by conodont and fusulinid zones. Four important sea-level falls are recognized in the area, which occur respectively at the basalSweetognathodus whitei zone, lowerS.aff.hanzhongensis zone, middleJinogondolella xuanhanensis zone and the basalClarkina yini zone. Among the recognized transgression events, three are regarded as the most significant. They occur respectively at the basalNeogondolella exculptus zone, basalJinogondolella nankingensis zone and the lowerClarkina postbitteri zone, and are all accompanied by faunal turnovers. The key surfaces in sequences can be used to fine-tune the boundaries of bio-chronozones, stages and series.展开更多
For a long time the Permian System in Southern China has been divided into two units, and the triple division suggestion has also been discussed abroad and at home.Southern Guizhou is a favourable area for research in...For a long time the Permian System in Southern China has been divided into two units, and the triple division suggestion has also been discussed abroad and at home.Southern Guizhou is a favourable area for research in the Permian division. Here, the Permian strata are fully developed. They are of various sedimentary types and are abundant in fossils. In 1984, Guizhou Petroleum Prospecting and Locating Command Department of PIM have launched a research in the Permian System of south-展开更多
基金We thank Sinopec Huadong Oil and Gas Branch for collection of data.The work was supported by the National Science and Technology Major Project(No.2016ZX05060,No.2016ZX05061)Sinopec Science and Technology Project(P15114).
文摘In order to investigate pore characteristics and formation mechanism in the high-maturity organic-rich shale of Lower Cambrian Jiumenchong Formation in southern Guizhou,the pore structure,pore type and storage properties are well studied through the rock thin section,total rock X-ray diffraction,lowtemperature nitrogen adsorption,high pressure mercury injection-adsorption test,helium porosity test,argon ion polishing-scanning electron microscope,thermal evolution and pore evolution history reconstruction,and based on the diagenesis and compaction as well as thermal evolution process,a microscopic pore formation and evolution model of high-maturity organic-rich shale are established.The result shows that the high-maturity organic-rich shale of Jiumenchong Formation has the average total specific surface area of 12.66m^(2)/g and the total pore volume of 11.54×10^(-3)cm^(3)/g,and the total specific surface area have a positive correlation with total pore volume;the total specific surface area and the total pore volume are slightly lower compared with the Lower Silurian shale.The pores are dominated by micropores and mesopores,while macropores are very rare.The pores of the organic-rich shale mainly are organic pores with small diameter usually less than 30 nm,and the pore boundary form is irregular,the inorganic mineral pores are not developed.Compared with the Silurian shale,the shale has poorer reservoir property,the average porosity is only 2.80%;the horizontal permeability is 1e3 times of the vertical permeability,indicating the horizontal lamellations are not developed.The formation and evolution of pores in high-maturity organic-rich shale is jointly influenced by the evolutionary process of intergranular pores of inorganic mineral under the control of the diagenesis and compaction,the organic pore formation process in the hydrocarbon generation-oil formation-oil and gas transformation sequence under the control of thermal evolution,and the natural gas loss-supply equilibration process under the condition of later pore preservation.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 40072006)the Program of the Ministry of Education of China for Young Teachers.
文摘A huge coral reef occurring in the Triticites belt of the Maping Formation, in Bianping Village, about 4 km west of Houchang Town from Ziyun County, Southern Guizhou, China is described. The coral reef has been well studied and some significant characteristics were dis-covered: the composition of reef-building community is very monotonous; there are only one or two builders in each reef-building stage; the dwellers are also poor in variety; the reef-building process is very simple; the reef has been separately built by various reef-building mechanisms, and there have been few parts built by two coexisting building mechanisms; the process of reef building is often discontinuous and lacks transition. All these characteristics are considered to be unique to the recovery stage of reef communities after F/F event and are representative of a process that reef communities must undergo post the catastrophe.
文摘This paper presents magnetic susceptibility results of 578 samples from three De-vono-Carboniferous carbonate successions in the Yangtze Block. They indicate that the magnetic susceptibility variations in carbonates are controlled by ancient sea-level changes. It is particularly so if the supply of detrital materials was low, when the magnetic susceptibility was mainly controlled by the content of authigenic minerals. If the supply of detrital materials was high, the average susceptibility value would be higher, but there is still a correlation between susceptibility and sea-level curves. A sea level rise would lead to a decrease in the content of the detrital materials, and therefore to a decrease in the susceptibility values. On the top of HST, the uplift and exposure events may lead to elevated magnetic susceptibility values. Carbonate susceptibilities can therefore be considered as one of the environmental proxy data for the research of sequence stratigraphy.
文摘The Permian in slope facies area of southern Guizhou consists of 16 third order sequences, which can be grouped as four sequence sets and further into two mesosequences. Most of them are delineated by conformable or submarine erosion surfaces, and well controlled by conodont and fusulinid zones. Four important sea-level falls are recognized in the area, which occur respectively at the basalSweetognathodus whitei zone, lowerS.aff.hanzhongensis zone, middleJinogondolella xuanhanensis zone and the basalClarkina yini zone. Among the recognized transgression events, three are regarded as the most significant. They occur respectively at the basalNeogondolella exculptus zone, basalJinogondolella nankingensis zone and the lowerClarkina postbitteri zone, and are all accompanied by faunal turnovers. The key surfaces in sequences can be used to fine-tune the boundaries of bio-chronozones, stages and series.
文摘For a long time the Permian System in Southern China has been divided into two units, and the triple division suggestion has also been discussed abroad and at home.Southern Guizhou is a favourable area for research in the Permian division. Here, the Permian strata are fully developed. They are of various sedimentary types and are abundant in fossils. In 1984, Guizhou Petroleum Prospecting and Locating Command Department of PIM have launched a research in the Permian System of south-
