准噶尔盆地春风油田沙湾组沉积相新认识

New understanding of sedimentary facies of Shawan Formation in Chunfeng Oilfield,Junggar Basin

春风油田位于准噶尔盆地西缘车排子凸起的东北部,对该区沙湾组沉积环境、物源方向以及沉积相类型等方面的认识仍存在一定分歧。在岩心观察的基础上,通过开展轻重矿物、粒度、微量元素分析等实验,结合测井相等方法对沉积相重新进行研究,认为该区主力产层沙湾组一段属于典型的水下沉积环境,砂体由北西和南西2个方向向油田中部交汇。沉积微相类型主要包括西北部的扇三角洲前缘水下分流河道,由南西向北东展布的辫状河三角洲前缘水下分流河道、分流间湾以及西部平行岸线局限分布的滩坝沉积。

The Chunfeng Oilfield locates in the northeast of the Chepaizi Uplift, the western margin of the Jung- gar Basin. The sedimentary environment, source direction and sedimentary facies of the Shawan Formation in the study area are still under discussion. Based on core observation, carrying out experiments of light/heavy mineral, grain size and trace element, combining with well logging facies, it has been concluded that, the first member of the Shawan Formation in the study area was deposited in a typical underwater sedimentary environment. Sandbodies migrated to basin center from northwest and southwest. Sedimentary microfacies mainly include subaqueous distributary channel of fan-delta front in the northwest, distributary channel and interdistributary bay of braided delta front which distribute from southwest to northeast, and a few beach-bar sandbodies parallel to coast in the west.