准噶尔盆地车排子地区侏罗系八道湾组沉积古地貌及岩性分布*

利用三维地震资料，对准噶尔盆地车排子地区侏罗系八道湾组各岩性段精细井震标定与构造解释，厘定出各岩性段在车排子地区的尖灭线位置和尖灭线类型，分析古地貌差异程度对尖灭线形成的控制作用。采用地层厚度法和地震层拉平法研究八道湾组各段沉积古地貌特征，分析断裂对古地貌形成的控制作用，结合构造演化剖面分析古地貌演化和被改造后的特征，开展地震属性、储集层地震反演和沉积相分析，重点分析古地貌对沉积和岩性的控制作用，再现了该地区沉积相及储集层段岩性分布特征。车排子地区八道湾组沉积古地貌起伏明显，呈坡—隆—凹组合特征，斜坡的陡缓程度对沉积相的类型和岩性及其沉积物的粗细具有重要控制作用。八道湾组不同沉积时期低隆起的形态和隆起幅度都存在较大的差别，且隆起幅度越高其聚砂特点越明显，沟谷既是输砂通道，也是聚砂的重要场所，现今砂体的分布与沟谷展布方向关系密切。

Sedimentary palaeogeomorphology and lithology distribution of the Jurassic Badaowan Formation in Chepaizi area of Jungar Basin

Based on 3D seismic data，through fine well-to-seismic calibrations and structure elucidations，this paper has found out the position and type of the pinchout lines of different lithohorizons in the Jurassic Badaowan Formation in Chepaizi area of Jungar Basin;meanwhile，it has also discussed the controlling of pinchout line formed by the extent of palaeogeomorphology variation.The sedimentary palaeogeomorphological features of different lithohorizons have been shown after stratigraphical thickness analysis and seismic layer flattening. By analyzing the fault controlling effects of palaeogeomorphology，together with tectonic evolution profiles，we have systematically illustrated the palaeogeomorphology evolution and the altered palaeogeomorphological features. After analysis of seismic property，reservoir seismic inversion and sedimentary facies，especially the focus analysis on the controlling of deposition and lithology by palaeogeomorphology，we have revealed the characteristics of the sedimentary facies and lithology distribution of reservoir intervals in this area.The sedimentary palaeogeomorphology of Badaowan Formation in Chepaizi area undulates obviously，showing the slope-uplift-depression combination features; meantime, the slope gradient plays an important role in controlling the type of sedimentary facies，lithology and the sediment grain size.The shape and amplitude of low uplift in Badaowan Formation varies greatly during different deposition stages，while the tendency of gathering sand is more apparent when uplift amplitude increases.The valley is not only the channel to transport sediment，but also the key place to accumulate sand，due to which，the sand body distribution of nowadays is closely related to the valley extention direction.