塔里木盆地轮南低凸起天然气分布规律与成藏期次

系统分析了塔里木盆地轮南低凸起天然气地球化学特征和有机包裹体均一化温度等资料，对天然气成因、分布规律和成藏期次进行了研究。结果表明:该区烃类气体主要为海相高成熟-过成熟腐泥型干气，可分为原油裂解气、干酪根裂解气和混合气3种成因类型；轮古东斜坡带产出特征明显的原油裂解气,轮古西斜坡带和中部斜坡带主体为干酪根裂解气,其他地区为混合气；烃类气体碳同位素序列倒转是由不同成熟度天然气混合与扩散分馏机制双重作用所致；氮气主要来源于高成熟－过成熟海相烃源岩热解，CO₂有壳源无机成因和有机成因两种来源；稀有气体同位素特征表明，轮南断垒带有少量幔源气混入，其他地区为典型的壳源气。奥陶系油气存在3期充注，分别为加里东晚期-海西早期、海西晚期和喜马拉雅中晚期，石炭系油气主要在喜马拉雅中晚期富集成藏。

Regularity of distribution and accumulation stages of natural gases in the Lunnan lower uplift of the Tarim Basin

To clarify several questions about the gas origin,regularity of distribution as well as stages of oil and gas accumulations in the Lunnan lower uplift,Tarim Basin,the present paper systematically dealt with geochemical characteristics of natural gases and the homogenization temperature of organic inclusions from the study area.The results showed that hydrocarbon gases in the study area were likely to be a marine sapropel-type dry gas with high to over maturity that could be divided into three types:A cracki...