黄骅坳陷孔南地区孔一段膏泥岩段的形成模式及层序地层学意义

Formation Model and Significance of Sequence Stratigraphy of Gypsum Mudstone Section on Member 1 of Kongdian Formation in Kongnan Area,Huanghua Depression

黄骅坳陷孔南地区孔一段顶部发育了一套特征的膏泥岩段,为孔店组勘探层系的盖层,对油藏勘探开发具有重要意义,膏泥岩段也是等时地层单元划分的重要标志层。主要以测井资料、录井资料为基础,利用等时地层对比方法,讨论了该区膏泥岩的分布特征、分布模式、沉积环境以及层序地层学意义。综合分析得出,膏泥岩段的分布总体上具有自东向西加厚和由南、北向中间加厚的特征,可分为4种分布模式类型:无膏泥岩沉积类型、自东向西膏泥岩层厚度减薄类型、膏泥岩厚度自沧州一捷地地区向两侧减薄类型、膏泥岩层自西向东减薄尖灭类型,其主要形成环境为暂时性的盐渍洼地和长期发育的盐湖,属高位体系域。

On the top of Member 1 of Kongdian Formation in Kongnan area,Huanghua Depression,there is a set of gypsum mudstone with some specific characteristics.It is the upper cover on the exploration layer in Kongdian Formation,and also the important marker bed of isochronal formation unit.Hence,it has of great significance for reservoir exploration and development.This article discusses the distribution features,distribution patterns,depositional environment and sequence stratigraphic significance of gypsum mudstone in this area using the isochronous stratigraphic correlation,mainly based on the log data,logging data.Based on the comprehensive analysis,it is concluded that the distribution of gypsum mudstone has the characteristics of thickening from east to west and from south,north to the middle,and also can be divided into four types of distribution pattern：the type of no gypsum mudstone sedimentary,the type of thinning from east to west,the type of thinning from Cangzhou-Jiedi to the two sides of it,the type of thinning from west to east until pinching-out.The environment of the formation is temporary saline depression and long-term developmental saline lake,thus belonging to HST.