叠合盆地油气运聚期次研究方法及应用

A method for studying the oil and gas migration stages in superposed basin and its application

我国多为陆相叠合盆地，具有多期生排烃、运移、成藏、调整和破坏的特点。归纳有关油气运移方面的文献，将油气运聚期次的研究方法归纳为４种：即以分析构造运动后地层表现形式的构造分析法、以研究流体包裹体为主要内容的储集层有机岩石学分析法、储集层成岩矿物（主要是伊利石）同位素地质年代法和用于推断储集层中烃类流体充注史、烃类注入方向和时间的油藏地球化学－油藏非均质性研究法。４种方法分别具不同的分析原理和应用效果，并在吐哈盆地分别进行了应用。构造分析法和储集层有机岩石学分析法得出葡北油田主要经历了侏罗纪末─早白垩世和晚第三纪两期油气大规模运移；葡北油田同位素地质定年分析只反映出油气第二期运移成藏时期，其原因是第一期油气没有充满取样层位所造成；油藏地球化学－油藏非均质性分析得出鲁克沁构造油藏是油气先稠化后成藏的结论。

After summarizing scholar's studies of petroleum migration at home and abroad, four methods for dating hydrocarbon migration period are summarized up. They are respectively tectonic analysis, reservoir organic petrology, diagenetic mineral isotopic dating and reservoir geochemistry-reservoir heterogeneity approach. Principles and application results of the four methods are generally introduced, including the application analysis for Turpan-Hami basin. Two periods for forming Pubei oil field have been identified by using the tectonic analysis and reservoir organic petrology approaches, which are, respectively, the period from late Jurassic to early Cretaceous and the late Tertiary. But the geologic isotopic dating indicates only the second migration period. The reason is that the sampling location is outside the Oil-water interface controlled by the first migration period. The oil was thickened first and migrated later according to reservoir geochemical analysis for Lukexin oil pool. The results are very significant for hydrocarbon resource evaluation and exploration in Turpan -Hami basin.