南堡2号构造东一段沉积微相研究

Study on Sedimentary Microfacies in Dong1 Member in Nanpu 2 Structure

以南堡2号构造古近系东营组一段为研究对象,开展东一段沉积微相展布及演化规律研究。通过岩心观察,测井相分析,结合骨架剖面的沉积微相和地震相研究表明,东一段为辫状河三角洲前缘沉积体系,主要发育水下分流河道、河口坝、远砂坝、席状砂和水下分流河道间沉积微相。其中水下分流河道和河口坝砂体等粗岩相与含油性的关系密切,为物性较好的储集相带,伴随着水体变浅,东一段整体上组成了一套向上岩性变粗、泥岩颜色变浅的反旋回沉积,反映了东一段沉积期湖盆不断萎缩、逐渐消亡的过程。该研究对研究区储层的认识和研究区的勘探开发具有一定指导意义。

Focusing on Paleogene Dongying 1 member( Dong1 member) in Nanpu 2 structure,distribution and evolution of microfacies were analyzed. By core observation,electrofacies analysis,and studies on sedimentary microfacies and seismic facies on framework sections,it was concluded that Dong1 member is the sedimentary system in braided river delta front facies,where sedimentary microfacies of underwater distributary channel,mouth bar,distal bar,sand sheet and underwater interdistributary channel are developed. Coarse lithofacies in microfacies of underwater distributary channel and mouth bar sand bodies have close relationship with oil-bearing properties. They are the accumulation facies belts with better physical properties. With the shoaling of water body,the whole Dong1 member composes a suite of anti-cyclic deposition whose lithology becomes coarser and mudstone colors become lighter upwards,which reflects the process of continuous suppression and gradual dying out of the lake basin during the deposit period of Dong1 member. This study provides certain guidance for cognition on reservoir and exploration and development in this study area.