【摘要】 针对准噶尔盆地东缘三工河组底部发育粗砂—砾岩沉积,异于盆地腹部与南缘,且相邻井区砂体发育状况差异明显的问题,分析坡折带对层序和沉积的控制作用.根据钻井、地震及露头资料识别关键层序界面,将三工河组划分为2个三级层序.识别挠曲和断裂2种构造坡折带,"径向沟梁辐射、纬向阶梯分布"的坡折带体系使得低位体系域发育;坡下沉积物卸载大量堆积;坡上侵蚀作用强烈.以彩9—C1805井区为例,识别6种沉积微相组合,前者为坡折发育的陡坡富河口坝型前缘,砂体连片性好;后者为坡折欠发育的缓坡富河道型前缘,砂体较孤立.因此,坡折带是富砂储层发育的有利地带,对油气预测勘探具有指导意义.更多还原

【Abstract】 According to the cores,outcrops,seismic data and wire-line logs,the Sangonghe formation in the eastern margin of Junggar basin is divided into 2 third-order sequences on the basis of recognition for the MFS,FFS,coals and sequence boundaries.Then 2 kinds of tectonic slope-breaks(faulted slopebreak and textual slope-break)are identified on well correlation and seismic profiles with flattened coal.The main effects exerted by slope-breaks on sequence stratigraphy and sedimentation of lacustrine delta are as follows:Firstly for sequence stratigraphy,the uplifts and troughs in radial direction as well as terrace-like slope breaks in zonal direction are favorable for LSTs.The slope-breaks will promote migration and reduce incision;the LST will erode underlying layers at high slope-breaks.Secondly for sedimentation,6 kinds of microfacies assemblages are recognized in the elaborate development area and 3 sequences of these assemblages are identified in the well correlation along provenance;the bars-rich delta front is developed in steep slope while the river-rich delta front in gentle slope.Consequently,with welldeveloped reservoir and high sandstone percent,slope breaks are the important targets during petroleum exploration.更多还原