摘要
至2003年底,中国发现6个千亿立方米以上储量规模的大气田,其中5个在鄂尔多斯盆地(苏里格、乌审旗、榆林、大牛地、靖边),1个在塔里木盆地(克拉2)。根据150个气样的组分、143个气样烷烃碳同位素和21个气样氦同位素的分析数据,这些大气田天然气具有以下地球化学特征①高含烷烃气,低含二氧化碳。烷烃气含量均在90%以上,多数在95%以上,二氧化碳含量基本低于3%,主要在1.5%之下。②烷烃碳同位素组成重,具有煤成气特征。δ13C1值为-38.5‰～-26.2‰,主峰值为-35‰～-32‰;δ13C2值为-35.3‰～-17.8‰,一般为-28‰～-24‰;δ13C3值为-29.9‰～-19.1‰,一般为-27‰～-23‰;δ13C4值为-25.6‰～-20.3‰,一般为-23.5‰～-22‰;δ13CiC4>δ13CnC4。大气田气源岩是石炭系-二叠系和中、下侏罗统煤系。③3He/4He值为n×10-7～n×10-8,具壳源氦特征。CH4/3He为n×1010～n×1011,说明CH4为有机成因。
By the end of 2003, 6 giant gas fields each with reserves of over 100 billion cubic meters （bcm） have been discovered in China, 5 of which, Sulige, Wushenqi, Yulin, Daniudi and Jingbian gas fields are located in Ordos Basin, and Kela 2 gas field, is located in Tarim Basin. According to the gas compositions of 150 gas samples, the alkane carbon isotope data of 143 gas samples, and helium isotopic data of 21 gas samples, the geochemical characters of the giant gas fields are as follows① The gases have a high alkane content of over 90% and the CO2 content lower than 3 %, mainly lower than 1.5% ; ② The generally high δ^13 C values of C1-C4 gaseous hydrocarbons in gases confirmed significant contribution from humic source rocks, mainly the Permian Carboniferous and the Middle-Lower Jurassic coal measures. The dominant ranges for δ^13 C1 , δ^13 C2 , δ^13 C3 and δ^13 C4 values in the Upper Paleozoic trapped gases are -35‰ to-32‰, -28‰ to -24‰, -27‰ to -23‰, and -23. ‰ to -22‰ respectively. The δ^13Cic4 value is higher than that of the δ^13Cnc4 . ③ The 3^He/4^He value is from n× 10^-8 to n× 10^-7 suggesting crustal origin. The CH4/3^He value is from n × 10^10 to n × 10^11 showing that the CH4 is of organic origin.
出处
《石油勘探与开发》
SCIE
EI
CAS
CSCD
北大核心
2005年第4期16-23,共8页
Petroleum Exploration and Development
基金
国家重点基础研究发展规划"973"项目(2001CB209103)
关键词
中国
天然气
大气田
千亿立方米
地球化学特征
China natural gas
giant gas field
hundred billioncubic meters
geochemical character
作者简介
戴金星（1935），男，浙江温州人，中国科学院院士，中国石油勘探开发研究院教授极高级工程师，从事天然气地质与地球化学研究。地址：北京市学院路20号，中国石油勘探开发研究院，院部，邮政编码：100083。E—mail：djx@petrochina．com．cn
