Geochemical characteristics of light hydrocarbons in natural gases from the Turpan-Hami Basin and identification of low-mature gas  

作　　者：SHEN Ping WANG XiaoFeng WANG ZhiYong MENG QianXiang XU YongChang 

机构地区：[1]State Key Laboratory of Oil and Gas Resources Research, Chinese Academy of Sciences, Lanzhou 730000, China [2]Institute of Exploration and Development, Tu-Ha Oilfield Company of China, Hami 839009, China

出　　处：《Chinese Science Bulletin》2010年第29期3324-3328,共5页

基　　金：supported by the National Petroleum Major Projects (2008ZX05008-001);the National Natural Science Foundation of China (40703001)

摘　　要：Theoretical and practical knowledge regarding low-mature gasses is of significant importance to identifying potential natural gas resources.Light hydrocarbon parameters and C and H isotopes are useful tools to identify low-mature gas.Twenty gas samples were collected from the Turpan-Hami Basin for light hydrocarbon analyses.The results showed that the light hydrocarbon components of natural gases contain high methylcycloxane,high isoparaffin and low benzene.This implies that the gas-generating parent materials are of typical humus type and the paleoenvironment is a fresh water sedimentary environment.These features are consistent with the geological setting of the basin.Comparative studies of isoheptane,heptane,and the carbon isotopic compositions of methane in natural gases,and other maturity indices indicated that natural gases in the Turpan-Hami Basin are dominated by low-mature gas formed during the low evolution stage of Jurassic coal seams.The parent materials are of type III,and the maturation degree was in the low evolution stage.These are the fundamental characteristics of low-mature gas.Results of light hydrocarbon research provided further evidence to suggest that the Turpan-Hami Basin is a large-scale gas producer of low-mature gas in China.It is likely that this resource will play an important role in future exploration and development of low-mature gas in China.Theoretical and practical knowledge regarding low-mature gasses is of significant importance to identifying potential natural gas resources. Light hydrocarbon parameters and C and H isotopes are useful tools to identify low-mature gas. Twenty gas samples were collected from the Turpan-Hami Basin for light hydrocarbon analyses. The results showed that the light hydrocarbon com- ponents of natural gases contain high methylcycloxane, high isoparaffin and low benzene. This implies that the gas-generating parent materials are of typical humus type and the paleoenvironment is a fresh water sedimentary environment. These features are consistent with the geological setting of the basin. Comparative studies of isoheptane, heptane, and the carbon isotopic composi- tions of methane in natural gases, and other maturity indices indicated that natural gases in the Turpan-Hami Basin are dominated by low-mature gas formed during the low evolution stage of Jurassic coal seams. The parent materials are of type III, and the maturation degree was in the low evolution stage. These are the fundamental characteristics of low-mature gas. Results of light hydrocarbon research provided further evidence to suggest that the Turpan-Hami Basin is a large-scale gas producer of low-mature gas in China. It is likely that this resource will play an important role in future exploration and development of low-mature gas in China.

关 键 词：天然气资源 地球化学特征 吐哈盆地 轻烃参数 低熟气 碳同位素组成 鉴定 母质类型 

分 类 号：P618.130.8[天文地球—矿床学] P618.51[天文地球—地质学]