东营南坡新生界与中古生界不整合面特征及对油气成藏的影响

受多期构造运动影响，东营凹陷形成多期不整合面。其中新生界与中古生界不整合广泛分布于凹陷之中，其上覆地层与下伏地层的接触关系多为削超样式。不整合结构层中的风化粘土层，经过成岩压实作用，极易固结，形成非渗透层，具有很好的封堵效应。由于风化淋滤作用，不整合面下的风化砂砾岩、碳酸盐岩等的渗透性均得到不同程度的改善，成为输导油气甚至储集油气的有利场所。油气在不整合中运移主要通过2种方式：不整合结构层侧向输导和不整合“天窗”式垂向输导。受不整合削超或平超式、砂/泥型或泥/砂型等多种岩性组合的控制，东营凹陷南斜坡多发育地层超覆、不整合削截油藏。

Features of Unconformity between Cenozoic and Mesozoic-Paleozoic and Its Effect on Hydrocarbon Accumulation in South of Dongying Sag

Under multiphase tectonic activity,many unconformities were formed in the Dongying sag.Among them,the unconformities between Tertiary and pre-Tertiary exist widely.The main contact between overlying and underlying formations is truncation-overlap.The weathered layer in the unconformity structure went through the diagenetic compression,and is easily solidified to form the impermeability layer with good sealing.Under the weathering and leaching action,the permeability of glutenite and carbonate under the unconformity is improved,and becomes a favorable area of oil and gas migration or accumulation.Two pathways of oil and gas migration in the unconformity are lateral and vertical.Since the multi-contact styles constrain the petroleum accumulation,such as truncation-overlap or parallelism-overlap and sand/mud or mud/sand,stratigraphic overlap and unconformity truncation,the stratigraphic overlap and unconformity truncation oil reservoirs occur generally in the south slope of Dongying sag.