海拉尔盆地乌尔逊凹陷北部断裂复杂,沉积成因类型多,油藏类型认识不清.应用高分辨率层序地层学原理和分析方法,以岩心、测井、地震资料为基础,通过研究区主要含油层段(南屯组二段、大磨拐河组一段)层序地层关键界面的识别与对比,逐级控制,建立了盆地高分辨率层序格架.研究表明,乌尔逊凹陷北部苏131、苏102断块油藏产油层段跨越两个三级层序界面,主要产油层段位于大磨拐河组一段三级层序底部,主要储层为低位域滑塌浊积岩储集体,而不是此前认为的南屯组二段三级层序顶部的扇三角洲前缘砂体.通过对研究区主要产油层段的层序地层位置重新厘定与对储集体成因类型详细分析,提出了乌尔逊凹陷北部地区油藏类型应该为构造-岩性油气藏的新认识,并分析了砂层组的时空展布特征,为该油田深入开发与扩边提供了依据.%The reservoir types are unclear in the northern Wuerxun Sag, the Hailar Basin, due to the complex fractures and various sedimentary genetic types. Based on the core, seismic and logging data, a high resolution sequence framework was established through the identification and comparison of key boundaries of the main oil-bearing formations, I. E. The second member of Nantun Formation (K1n2) and the first member of Damoguaihe Formation (K1d1). The pay zones cross two third-order sequence boundaries in the Su 131 and Su 102 fault-block reservoirs. The main reservoir is the low-system-tract slumped turbidite located at the bottom of the third-order sequence instead of the fan-delta front sand body located at the top of third-order sequence. Based on redefinition of the sequence-stratigraphic position of the main pay zone and analysis of reservoir genetic types, it is proposed that the reservoir in the northern Wuerxun Sag is of structural-lithologic type. In addition, the temporal and spatial distribution of sand units is analyzed. These understandings lay a solid basis for further development and extension of the oilfield.
展开▼
