长岭断陷登娄库组天然气成因类型分析

The gas forming laws in Denglouku group of Changling fault depression, Songliao basin

天然气成因类型判识是整个天然气成藏研究的核心内容之一。本文利用天然气组分特征、碳同位素特征等测试资料,对长岭断陷登娄库组天然气的成因类型进行了综合判断。长岭断陷深层(K 1yc+K 1d)天然气以来自营城组和沙河子组的高-过成熟煤型气为主,并混有部分油型气,不同成因类型天然气的混合导致碳同位素系列的倒转。此外,少数构造可见纯度较高的幔源二氧化碳气藏。因此,综合天然气的地化特征及该区的石油地质条件判断,长岭断陷登娄库组天然气既有有机成因气,也不排除无机成因的可能。

The research on genetic types of natural gas is main contents in this paper.The genetic types of natural gas is studied by using component and carbon isotope characteristics of gases.The deep gases in ChangLing fault depression are constituted of coaliferous and oil-formed gases which come from Yingcheng and Shahezi groups,this admixture leads to reserval of δ13C series.There are a few mantle-derived high-purity carbon dioxide gas reservoirs.Based on the analysis of geochemical characteristics of natural gas and geological conditions in Changling fault depression,the natural gas is organic as well as inorganic.