库车前陆盆地天然气成藏过程及聚集特征

Accumulation and Features of Natural Gas in the Kuqa Foreland Basin

天然气的组分和碳同位素主要受母质类型和成熟度双重因素的控制,这是我们研究天然气的基础。但是越来越多的证据显示成藏过程对天然气组分和碳同位素也具有明显的控制作用。尽管库车前陆盆地不同构造单元的天然气来源一致,即主要来源于侏罗系烃源岩、其次为三叠系烃源岩,但是库车前陆盆地冲断构造带、斜坡区和前缘隆起区在天然气组分、干湿程度和碳同位素组成上具有明显的差异。库车前陆盆地经历了早期油气的聚集、破坏和晚期天然气聚集、调整的过程,研究认为成藏过程对库车前陆盆地不同构造单元的天然气组分和碳同位素特征具有明显的控制作用。

The component and carbon isotope of natural gas are mainly controlled by the type of organic matter and maturity. But, more and more examples indicate that the accumulation process of natural gas also control the component and carbon isotope of natural gas. Although the natural gas in the different structural belt of the Kuqa foreland basin has the same original source, mainly generated by Jurassic source rock and less Triassic source rock, the natural gas in the overthrust belt, slope zone and forebulge zone of the Kuqa foreland basin was obviously different in component, content of dry and wet gas and carbon isotope. The accumulation history of hydrocarbon in the Kuqa foreland basin was that the early accumulated hydrocarbon was destructed and then hydrocarbon generated in late stage accumulated. The paper indicated that the accumulation process of hydrocarbon obviously controlled the component and carbon isotope of natural gas in the different structural belt of the Kuqa foreland basin.