构造演化与含油气系统的形成——以准噶尔盆地东部吉木萨尔凹陷为例

RELATIONSHIP BETWEEN TECTONIC EVOLUTION AND PETROLEUM SYSTEM FORMATION——TAKING THE JIMSAR SAG OF EASTERN JUNGGAR BASIN AS AN EXAMPLE

准噶尔盆地东部自晚石炭世洋壳消减后进入陆相盆地演化阶段,是一个构造演化复杂、由多个含油气凹陷和凸起构成的构造带,其构造演化历史主要分为4个阶段,即裂谷—断陷盆地阶段、断—坳盆地阶段、陆内坳陷盆地阶段和再生前陆盆地阶段。结合盆地东部吉木萨尔凹陷复合含油气系统特征,探讨了构造演化与含油气系统形成之间的关系。研究表明,构造演化在一定程度上控制着生储盖组合的形成,影响烃源岩的演化进程,控制着含油气系统的多期生烃和多期成藏,构成含油气系统的运聚、改造和后期保存的关键时刻。

The eastern Junggar Basin has entered the stage of continental basin evolution since the late Carboniferous. It is composed of several hydrocarbon bearing sags and uplifts with complicated tectonic evolution history, which can be divided into 4 stages： rift-faulted basin during Pemian, faulted-depression basin from Triassic to Jurassic, intra-continental depression basin from Cretaceous to Eocene, and rejuvenated foreland basin during late Cenozoic. Tectonic evolution of the Jimsar Sag has great influence on petroleum system formation in the following 3 aspeots： a） Tectonic evolution controls the formation of source rocks and source-reservoir-caprock assemblages; b） Tectonic evolution is likely to postpone the evolution processes of source rocks; c） The most important, tectonic evolution may control the multiphase hydrocarbon generation and the multi-phase pool forming of every petroleum system, which make up of the critical moments for hydrocarbon migration, accumulation, rebuilding and preservation of composite petroleum system.