There is promising indication of helium-rich natural gas in Weihe Basin.However,the lack of a detailed investigation on the origin and the spatial distribution of helium source rocks(mainly Yanshanian granites)limits ...There is promising indication of helium-rich natural gas in Weihe Basin.However,the lack of a detailed investigation on the origin and the spatial distribution of helium source rocks(mainly Yanshanian granites)limits the helium potentiality evaluation in Weihe Basin(WB).We performed three-dimensional(3 D)inversions of magnetic data in Weihe Basin and its adjacent areas to figure out the crustal thermal structure and the temporal-spatial distribution of deep granite in the basin.Based on this,we have proposed a geological model of helium accumulation and predicted the potential area of helium distribution.The results of 3 D magnetic inversion indicate that the granites in the deep Weihe Basin are mostly located at the central and southern parts of the basin,which are connected spatially with the granites in the North Qinling Orogenic Belt.These granites were all derived from largescale intra-continental orogeny in the Qinling area during the mid-Mesozoic,providing a good material basis for crust-derived helium in the basin.The local uplift of the Curie surface makes the thermal fluid more actively,which contributes to helium accumulation.The faults developed in the WB are the migration pathway of crust-derived helium and the upward migration of the mantle-derived helium.The wells with high percentage helium are mostly located near the Weihe fault and the areas on the south of it.The Wugong-Xi’an-Lantian area in the central and the Lintong-Weinan-Tongguan area in the eastern Weihe Basin are the most promising helium distribution areas.Furthermore,the region from the north of Taibai Mountain to Baoji City in the western Weihe Basin may also be another potential area of Helium resource.展开更多
This study aims to determine the effects of nanoscale pores system characteristics on CH4 adsorption capacity in anthracite.A total of 24 coal samples from the southern Sichuan Basin,China,were examined systemically u...This study aims to determine the effects of nanoscale pores system characteristics on CH4 adsorption capacity in anthracite.A total of 24 coal samples from the southern Sichuan Basin,China,were examined systemically using coal maceral analysis,vitrinite reflectance tests, proximate analysis,ultimate analysis,low-temperature N2 adsorption-desorption experiments,nuclear magnetic resonance (NMR)analysis,and CH4 isotherm adsorption experiments.Results show that nano-pores are divided into four types on the basis of pore size ranges:super micropores (<4 nm),micropores (4-10 nm),mesopores (10-100 nm),and macropores (>100 nm).Super micropores,micropores,and mesopores make up the bulk of coal porosity,providing extremely large adsorption space with large intemal surface area.This leads us to the conclusion that the threshold of pore diameter between adsorption pores and seepage pores is 100 nm.The "ink bottle"pores have the largest CH4 adsorption capacity, followed by semi-opened pores,whereas opened pores have the smallest CH4 adsorption capacity which indicates that anthracite pores with more irregular shapes possess higher CH4 adsorption capacity.CH4 adsorption capacity increased with the increase in NMR porosity and the bound water saturation.Moreover,CH4 adsorption capacity is positively correlated with NMR permeability when NMR permeability is less than 8 ×10^-3 md.By contrast,the two factors are negatively correlated when NMR permeability is greater than 8 × 10^-3 md.展开更多
The ongoing collision and continuous compression between the Indian and Eurasian plates began 55 Ma ago[1-3];this process created the magnificent Tibetan Plateau,the highest-elevation landform on the Earth today.Studi...The ongoing collision and continuous compression between the Indian and Eurasian plates began 55 Ma ago[1-3];this process created the magnificent Tibetan Plateau,the highest-elevation landform on the Earth today.Studies have shown that a continent-continent collision occurred not only south of the Tibetan Plateau but also north of the plateau[4].展开更多
基金supported by the National Natural Science Foundation of China(No.41904115)the Natural Science Basic Research Plan in Shaanxi Province of China(No.2018JQ4034)。
文摘There is promising indication of helium-rich natural gas in Weihe Basin.However,the lack of a detailed investigation on the origin and the spatial distribution of helium source rocks(mainly Yanshanian granites)limits the helium potentiality evaluation in Weihe Basin(WB).We performed three-dimensional(3 D)inversions of magnetic data in Weihe Basin and its adjacent areas to figure out the crustal thermal structure and the temporal-spatial distribution of deep granite in the basin.Based on this,we have proposed a geological model of helium accumulation and predicted the potential area of helium distribution.The results of 3 D magnetic inversion indicate that the granites in the deep Weihe Basin are mostly located at the central and southern parts of the basin,which are connected spatially with the granites in the North Qinling Orogenic Belt.These granites were all derived from largescale intra-continental orogeny in the Qinling area during the mid-Mesozoic,providing a good material basis for crust-derived helium in the basin.The local uplift of the Curie surface makes the thermal fluid more actively,which contributes to helium accumulation.The faults developed in the WB are the migration pathway of crust-derived helium and the upward migration of the mantle-derived helium.The wells with high percentage helium are mostly located near the Weihe fault and the areas on the south of it.The Wugong-Xi’an-Lantian area in the central and the Lintong-Weinan-Tongguan area in the eastern Weihe Basin are the most promising helium distribution areas.Furthermore,the region from the north of Taibai Mountain to Baoji City in the western Weihe Basin may also be another potential area of Helium resource.
基金This research was funded by the Open Foundation of Key Laboratory of Tectonics and Petroleum Resources (China University of Geosciences)(No.TPR-2016-04)the Open Foundation of Shandong Provincial Key Laboratory of Depositional Mineralization & Sedimentary Mineral,(Shandong University of Science and Technology)(No. DMSM2017031)+3 种基金the Youth Science and Technology Innovation Fund Project (Xi'an Shiyou University)(No.290088259)the National Science and Technology Major Project (No.2017ZX05039001-002)the National Natural Science Foundation of China (Grant Nos.41702127 and 41772150)the Scientific Research Program Funded by Shaanxi Provincial Education Department (No.17JK0617).
文摘This study aims to determine the effects of nanoscale pores system characteristics on CH4 adsorption capacity in anthracite.A total of 24 coal samples from the southern Sichuan Basin,China,were examined systemically using coal maceral analysis,vitrinite reflectance tests, proximate analysis,ultimate analysis,low-temperature N2 adsorption-desorption experiments,nuclear magnetic resonance (NMR)analysis,and CH4 isotherm adsorption experiments.Results show that nano-pores are divided into four types on the basis of pore size ranges:super micropores (<4 nm),micropores (4-10 nm),mesopores (10-100 nm),and macropores (>100 nm).Super micropores,micropores,and mesopores make up the bulk of coal porosity,providing extremely large adsorption space with large intemal surface area.This leads us to the conclusion that the threshold of pore diameter between adsorption pores and seepage pores is 100 nm.The "ink bottle"pores have the largest CH4 adsorption capacity, followed by semi-opened pores,whereas opened pores have the smallest CH4 adsorption capacity which indicates that anthracite pores with more irregular shapes possess higher CH4 adsorption capacity.CH4 adsorption capacity increased with the increase in NMR porosity and the bound water saturation.Moreover,CH4 adsorption capacity is positively correlated with NMR permeability when NMR permeability is less than 8 ×10^-3 md.By contrast,the two factors are negatively correlated when NMR permeability is greater than 8 × 10^-3 md.
基金supported by the National Natural Science Foundation of China(41874123 and 42004110)PetroChina Innovation Foundation(2010D-5006-0303 and 2014D-5006-0303)Shaanxi Provincial Natural Science Basic Research Project(2011JQ5006,2017JZ007 and 2022GY-148)。
文摘The ongoing collision and continuous compression between the Indian and Eurasian plates began 55 Ma ago[1-3];this process created the magnificent Tibetan Plateau,the highest-elevation landform on the Earth today.Studies have shown that a continent-continent collision occurred not only south of the Tibetan Plateau but also north of the plateau[4].
