准噶尔盆地湖底扇沉积特征及地球物理响应——以克拉玛依油田五八区二叠系下乌尔禾组为例

Sedimentary characteristics and geophysical responses of sublacustrine fan in the Junggar Basin:a case study on the Lower Urho Formation of the Permian in the Wuba block,Karamay oilfield

吴涛 赵长永 吴采西 苏艳丽 周作铭 张顺存 史基安

Wu Tao Zhao Changyong Wu Caixi Su Yanli Zhou Zuoming Zhang Shuncun Shi Jian

以准噶尔盆地克拉玛依油田五八区为例,综合利用岩心分析、薄片鉴定、分析化验和测井等资料,通过对二叠系下乌尔禾组湖底扇砂岩体岩石学、结构特征等方面的研究,认为下乌尔禾组湖底扇较发育,具有典型浊流沉积所形成的鲍马序列,沉积结构上也具有典型浊流沉积的粒度分布特征。地震正演模拟结果证实湖底扇具有敏感的地震响应。通过平均瞬时相位属性、相位调谐体频率切片、层拉平切片等地震多属性的刻画与储层反演,精细刻画砂体空间分布特征。湖底扇砂岩体地震剖面上具有典型的楔状杂乱反射、斜交反射以及透镜状反射特征。平面上南北向成群展布,分布范围广,砂泥岩配置关系良好,空间上呈透镜状展布。湖底扇砂岩体毗邻烃源岩,储盖组合良好,易形成岩性圈闭,油气成藏条件优越,对岩性油气勘探具有重要意义。

Sublacustrine fans were identified firstly in the Junggar Basin through integrated methodology of geology and geophysics.Data gathered from core sampling,testing,logging,and 3D seismic analysis of the Wuba block in Karamay Oilfield of Juggar Basin,show that the fans develop well in the lower Urho Formation of the Permian in the area.Study on the sedimentary facies,petrology and texture reveals that the fans have Bouma sequence and grain size distribution typical of turbidite deposits.Forward seismic modeling confirms the sensitive responses of the fans.The spatial distribution of fans was finely described with several seismic technologies including seismic multi-attributes,spectrum decomposition and seismic slices.The sandbodies in the fans occur as chaotic reflection,oblique reflection and lenticular reflection on seismic profiles.On plane view,they are widely distributed in clusters with good sandstone and mudstone combinations,while in space,they show lens shapes.These sandstone reservoirs and source rocks are close and in good combination,favorable for forming litholohic traps.These fans bear great significance to the exploration of lithologic reservoirs in the region.

10.11743/ogg20130111