松辽盆地双城—太平川地区天然气成因类型及气源

Gas source rocks and gas genetic type in Shuangcheng-Taipingchuan area of Songliao Basin

对松辽盆地双城—太平川地区中浅层天然气地球化学特征的分析表明,该区天然气为高-过成熟的煤型气,来源于深部的白垩系沙河子组和侏罗系含煤地层。本区天然气的碳同位素组成具有倒转序列特征,这主要是由腐殖型母质的“同型不同源”气或“同源不同期”气的混合造成的,同时也不排除由天然气中某一或某些组分被细菌氧化所造成。本区天然气中稀有气体氦的含量相对较高,有11口井天然气中氦的含量均具有工业开采价值,可作为氦气藏开采。

The geochemical characteristic analysis of natural gas in Shuangcheng-Taipingchuan area of Songliao Basin indicates that natural gas in this region is characterized by coal-type gas with high and over thermal maturity. The coal-type gas came from deep coal-bearing strata of the Shahezi Formation and Jurassic. The reverse series of carbon isotope composition of natural gas in this area is mainly caused by the same-type and different-source gas or the same source and different-phase gas in humic-type organic matter and probably brought by microbe oxidation of some components in natural gas. Helium content in natural gas of this area is relative high. Helium contents of eleven gas wells in this region are valuable to be explored as helium gas pool.