饶阳凹陷大王庄地区古近系层序地层特征

Sequence Stratigraphy of Palaeogene in Dawafngzhuang Area,Raoyang Sag

运用地层基准面原理和分析方法,综合研究钻井、测井和三维地震资料,在饶阳凹陷大王庄地区古近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-震精细标定的基础上建立了层序地层格架。饶阳凹陷大王庄地区古近系东营组至沙三段发育9个层序界面,将其划分为2个超长期基准面旋回(二级层序)和8个长期基准面旋回(三级层序);分析古近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、沉积微相构成。确定沙一段是大王庄地区最重要的岩性油藏勘探目的层系,其储集层类型主要为三角洲前缘分流河道砂和滩坝砂;有利储集相带主要分布于基准面上升期和下降期的早期。

The identification signs of the Paleogene sequence boundary are distinguished and two kinds of sequence boundaries, unconformity and shift surface of deposition, are identified according to drilling, logging and 3D seismic data in Dawangzhuang area, Raoyang sag by using the ways and principles of the high resolution sequence stratigraphy. Two super-term stratigraphic base level circles （the 2nd sequence） and the corresponding 8 long-term stratigraphic base level circles （ the 3rd sequence） could be distinguished in Paleogene in the study area within the nine sequence boundaries. Stratigraphic frames are built on the basis of the well and seismic-data calibration. It is confirmed that the first segment of Shahejie Formation is the key target series for exploration in the study area according to the sedimentary facies, Which reservoir sands are the beach bar and distributary channel sandstone of delta front. The distribution of advantaged reservoir is closely related to their position in the sequence and mainly developed at the half cycle of increasing and the early of the descending base level cycle.