Helium and argon isotope geochemistry of natural gases in China's petroliferous basins  

作　　者：LIU Wenhui XU Yongchang TAO Mingxin ZHANG Xiaobao 

机构地区：[1]Key Laboratory of Petroleum Resources Research, Institute of Geology and Geophysics, Chinese Academy of Sciences, Lanzhou730000, China [2]Research Institute of Petroleum Exploration and Production, SINOPEC, Beijing 100083, China [3]Key Laboratory of Environmental Change and Natural Disaster of Ministry of Education, College of Resource Science andTechnology, Beijing Norma University, Beijing 100875, China

出　　处：《Chinese Journal Of Geochemistry》2011年第1期19-32,共14页中国地球化学学报

基　　金：supported by the Chinese Natural Science Foundation Project (40673018)

摘　　要：The age-accumulation effect of 40Ar in hydrocarbon source rocks was discussed in accordance with the decay law of radioactive elements. In terms of the mean values of 40Ar/36Ar, the old Sinian gas reservoirs (mean values of 40Ar/36Ar: 7009) were definitely distinguished from the Permian gas reservoirs (mean values of 40Ar/36Ar: 1017) in Weiyuan, Sichuan Province, and the gas source of the Permian gas reservoir (mean values of 40Ar/36Ar: 5222) in well Wei-7 with the Weiyuan structure is defined as the Sinian system. Based on the values of 40Ar/36Ar, the coal-type gases (The source rocks are of the C-P system; mean values of 40Ar/36Ar: 1125) are definitely distinguished from the oil-type gases (The source rocks are of the Tertiary system; mean values of 40Ar/36Ar: 590) in the Tertiary reservoirs of the Zhongyuan Oilfield. Besides, 40Ar/36Ar values also have a positive effect on the oil-source correlation of oil reservoirs in ancient hidden mountains. According to the crust-mantle interchange information reflected by 3He/4He values, petroliferous provinces in China can be divided into three major tectonic regions. (1) The eastern active region: The crust-mantle volatile matter exchanges actively, and the 3He/4He values are mainly around 10-6, partly around 10-7. (2) The central stable region: The 3He/4He values are all around 10-8. (3) The western sub-stable region: The 3He/4He values are mainly around 10-8, and around 10-7 on the edges of the basins. Helium contents of some gas wells in China’s eastern petroliferous region reach the industrial abundance (He≈0.05%–0.1%), the 3He/4He values reach 10-6, and the equivalent values for the mantle-source components in helium gas can reach 30%–50%. As viewed from this, a new type of crust-mantle composite helium resources has been proposed. Geneses of some CO2 gas reservoirs in the east of China and some issues concerning mantle-source methane were discussed in the light of the helium and carbon isotopes of CO2 and CH4 in natural gases. In the discussion on helium The age-accumulation effect of 40Ar in hydrocarbon source rocks was discussed in accordance with the decay law of radioactive elements. In terms of the mean values of 40Ar/36Ar, the old Sinian gas reservoirs （mean values of 40Ar/36Ar： 7009） were definitely distinguished from the Permian gas reservoirs （mean values of 40Ar/36Ar： 1017） in Weiyuan, Sichuan Province, and the gas source of the Permian gas reservoir （mean values of 40Ar/36Ar： 5222） in well Wei-7 with the Weiyuan structure is defined as the Sinian system. Based on the values of 40Ar/36Ar, the coal-type gases （The source rocks are of the C-P system; mean values of 40Ar/36Ar： 1125） are definitely distinguished from the oil-type gases （The source rocks are of the Tertiary system; mean values of 40Ar/36Ar： 590） in the Tertiary reservoirs of the Zhongyuan Oilfield. Besides, 40Ar/36Ar values also have a positive effect on the oil-source correlation of oil reservoirs in ancient hidden mountains. According to the crust-mantle interchange information reflected by 3He/4He values, petroliferous provinces in China can be divided into three major tectonic regions. （1） The eastern active region： The crust-mantle volatile matter exchanges actively, and the 3He/4He values are mainly around 10-6, partly around 10 7. （2） The central stable region： The 3He/erie values are all around 10 s. （3） The western sub-stable region： The 3He/4He values are mainly around 10 8, and around 10-7 on the edges of the basins. Helium contents of some gas wells in China＇s eastern petroliferous region reach the industrial abundance （He≈0.05%-0.1%）, the 3He/4He values reach 10-6, and the equivalent values for the mantle-source components in helium gas can reach 30% 50%. As viewed from this, a new type of crust-mantle composite helium resources has been proposed. Geneses of some CO2 gas reservoirs in the east of China and some issues concerning mantle-source methane were discussed in the light of the helium and carbon isotopes of CO2 and C

关 键 词：中国东部地区 含油气盆地 天然气井 同位素地球化学 氦气 气藏成因 甲烷碳同位素 区域构造运动 

分 类 号：P618.130.2[天文地球—矿床学] TE375[天文地球—地质学]