华北黄骅坳陷层序地层学研究——以白水头-唐家河地区Es1-Nm为例

根据层序地层学理论，对地质、钻井、测井及地震等资料进行综合分析，将华北黄骅坳陷白水头-唐家河地区的沙河街组一段（Es₁）-明化镇组（Nm）地层划分为2个一级层序，4个二级层序，从下向上依次为：层序Ⅰ（对应于沙河街组一段）、层序Ⅱ（对应于东营组）、层序Ⅲ（对应于馆陶组）、层序Ⅳ（对应于明化镇组）。其中层序Ⅰ和Ⅱ为湖泊相层序，分为低位（LST）、湖扩展（EST）和高位（HST）等3个沉积体系域；层序Ⅲ和Ⅳ为河流相层序，分为基准面上升和基准面下降等2个沉积体系域。在此基础上，分析了湖泊相和河流相层序的沉积特征，总结了本区层序地层的发育模式。最后指出，层序Ⅰ的HST，层序Ⅱ的LST，层序Ⅲ的基准面上升体系域为本区最有利的油气勘探目标层段；层序Ⅳ主要发育岩性圈闭。

STUDY ON SEQUENCE STRATIGRAPHY OF HUANGHUA DEPRESSION IN NORTH CHINA: TAKING Es1-Nm STRATA IN BAISHUITOU-TANGJIAHE AREA AS EXAMPLES

Based on the theory of sequence stratigraphy and through comprehensive analyses of geologic, drilling, logging, and seismic data, the first member of Shahejie Formation (Es1) the Minghuazhen Formation (Nm) in Baishuitou Tangjiahe area in Huanghua depression are divided into 2 first order and 4 second order sequences. They are successively, from the bottom to the top, the sequence Ⅰwhich corresponds to the first member of Shahejie Formation, the sequence Ⅱ which corresponds to the Dongying Formation, the sequence Ⅲ which corresponds to the Guantao Formation, and sequence Ⅳ which corresponds to the Minghuazhen Formation. Of these second order sequences, the sequence Ⅰ and Ⅱ are of lacustrine facies, and can be divided into 3 depositional system tracts, including lowstand system tract (LST), lake expanding system tract (EST) and highstand system tract (HST). While the sequence Ⅲ and Ⅳ are of fluvial facies and can be divided into a base level ascending and a base level descending system tracts. Based on sequence division and stratigraphic correlation, sedimentary features of lacustrine facies sequence and fluvial facies sequence are analyzed, and a sequence stratigraphic model is built in the study area. It is believed that the HST of sequence Ⅰ, LST of sequence Ⅱ and base level ascending system tract of sequence Ⅲ are the most favorable exploration targets in the study area. The HST of sequence Ⅰ is dominated by stratigraphic unconformity traps, the base level ascending system tract of sequence Ⅲ is dominated by structural lithologic traps, and the sequence Ⅳ is dominated by lithologic traps.