塔里木盆地库车油气系统属于超强充注类型的油气系统。该系统的源、盖条件非常优越,加之区域盖层之下分布着第三系底部和白垩系的良好砂岩储集层,使系统内油气不仅在油源区内以垂向充注为主的近端聚集形成大型气藏,而且在距离油源区20～30km的远端形成以侧向运聚为主的中型凝析油气田。依据成藏作用的差异可将该系统分为南部和北部两个亚系统,两个亚系统中的成藏机制和主控因素是不同的,可建立3种成藏模式,即北部亚系统的克拉苏模式和大宛齐模式,南部亚系统的牙哈模式。北部亚系统临近烃源区,第三系膏盐质盖层非常发育,白垩系储集层厚度巨大、物性良好,背斜圈闭众多,是库车油气系统气藏勘探的最有利地带,克拉苏模式是当前寻找大中型气藏勘探目标的主要类型。图4表2参3 （周兴熙摘）%According to the difference of reservoir-forming process, the Kuqa petroleum system, belonging to the super-charged system, can be divided into two subsystems, southern and northern subsystems. The forming mechanism and the key factors controlling reservoir-forming process and model of both subsystems are very different, three kinds of the reservoir-forming models—Kelasu Model, Dawanqi Model and Yaha Model can been built up, and the Kelasu Model will be the useful kind in searching large gas pool in the north subsystem which is near the source rocks, its Tertiary cap rock well developed and the Cretaceous reservoir is huge in thickness, good in properties and much in trap number.
展开▼
