准噶尔盆地中部侏罗系层序地层格架

应用层序地层学地层基准面的原理和方法，综合研究准噶尔盆地中部钻井、测井及地震资料，确定层序界面的识别标志，在盆地中部侏罗系识别出两种层序界面类型(不整合面和沉积作用转换面)，在井一震标定的基础上建立了层序地层格架。准噶尔盆地中部侏罗系发育5个具有等时意义的层序界面，将其划分为4个长期基准面旋回，分析侏罗系不同层序基准面上升期与下降期地层叠加样式及沉积相、微相构成，确定三工河组是盆地中部最重要的勘探目的层系，其储集层类型主要为三角洲前缘河口坝和水下分支水道．有利储集相带的展布与所处层序地层位置密切相关，主要分布于基准面上升期。图6参9

Jurassic sequence stratigraphic frames in the Middle Junggar Basin

The identification signs of the Jurassic sequence boundary are determined and two kinds of sequence boundaries, unconformity and shift surface of deposition, are identified according to drilling, logging and seismic data in the middle Junggar Basin. Five Jurassic sequence boundaries are developed as four long-term base level cycles further in the middle basin. Stratigraphic frames are built on the basis of well and seismic-data calibration. It is confirmed that the Sangonghe Formation is the key target series for exploration in the middle basin where reservoir sands are the river mouth bar and distributary channel sandstones of delta front. The distribution of advantaged reservoir facies is closely related to their position in the sequence and mainly developed at the half cycle of increasing A/S conditions.