天然气中氦同位素分布及构造环境

通过采集天然气样３３４个，测量了它们的氦同位素组成。３Ｈｅ／４Ｈｅ值分布在０５６×１０－８～７２１×１０－６范围。３Ｈｅ／４Ｈｅ值分布与天然气储层时代无明显的相关性，而在空间展布上有较明显的规律。东部含油气区３Ｈｅ／４Ｈｅ值主要分布于１０－７～１０－６范围，西部含油气区在１０－７～１０－８的范围，中部地区分布在０５６×１０－９～０５６×１０－８范围，３Ｈｅ／４Ｈｅ值的分布与我国构造环境大的格局有很好的相关性。３Ｈｅ／４Ｈｅ的高值区构造环境活动性强，低值区具有最稳定的大地构造属性，西部地区３Ｈｅ／４Ｈｅ值介于东部和中部，具有次稳定的构造环境。

HELIUM ISOTOPE DISTRIBUTION OF NATURAL GASSES AND ITS STRUCTURAL SETTING

Based on the research of the helium isotope composition within 334 natural gas samples, it is found that the 3He/ 4He ratio is 0.56×10 -8 ～7.21×10 -6 . Though there is no evident relativity between the distribution of 3He/ 4He ratio and the age of natural gas reservoir, but indeed the ratio distributes regularly in space. In general, the 3He/ 4He ratio is 10 -7 ～10 -6 in the oil gas bearing area in East China, 10 -7 ～10 -8 in West China and 0.56×10 -9 ～0.56×10 -8 in midland. The distribution of 3He/ 4He ratio is distinctly related to the structural setting. The area of higher 3He/ 4He ratio is the most active structural setting, the area of lower 3He/ 4He ratio is the most stable and the midland is the sub stable one, where the 3He/ 4He ratio is between the East and West of China.