中国大气田地球化学特征

Geochemical Characteristics of Large Gas Fields in China

通过对中国48个大气田的地球化学特征进行总结,分析大气田组分、气源以及混合烷烃气,主要地球化学特征主要有:大气田中天然气组分主要以烷烃气为主,其中甲烷的平均含量为88%,乙烷、丙烷、丁烷的平均含量分别为3.3%、1.0%、0.5%;苏里格是我国年产气量最大与储量最大的气田,其分别占全国的15%、13%;我国大气田天然气主要以煤成气为主,油型气为辅,分别为27个和21个;混合烷烃气由于不同比例分为靖边型混合烷烃气、普光型混合烷烃气、徐深型混合烷烃气,并分析了各混合烷烃气成因。

Geochemical characteristics of 48 major gas fields in China were summarized.Gasfield components, gas source and mixed alkane gas were analyzed. The results show that main geochemical characteristics are as follows： main component of natural gas is alkane, the average content of methane is 88%, the average contents of ethane, propane and butane are 3.3%,1% and 0.5%; Sulige gas field has the largest gas reserve and the largest annual gas production in China, accounting for 15% and 13%; gas in China is mainly coal formed gas, oil type gas is supplement; due to the different proportion, the mixed alkane gas is divided into Jingbian mixed alkane gas, Puguang mixed alkane gas ,Xushen mixed alkane gas. At last, the causes of mixed alkane gas formation were analyzed.