渤海湾盆地黄河口凹陷SC7区块古近系东营组二段下亚段滩坝储集体构型特征  

Architectural characteristics of beach-bar reservoirs in the lower submember of the 2nd member of the Paleogene Dongying Formation in block SC7,Huanghekou Sag,Bohai Bay Basin

作　　者：邵长印 宋璠[1] 张世奇[1] 王秋月 SHAO Changyin;SONG Fan;ZHANG Shiqi;WANG Qiuyue(State Key Laboratory of Deep Oil and Gas,China University of Petroleum(East China),Qingdao,Shandong 266580,China;Geological Research Institute of Binnan Oil Production Plant in Shengli Oilfield,Binzhou,Shandong 256600,China)

机构地区：[1]深层油气全国重点实验室中国石油大学(华东),山东青岛266580 [2]中国石化胜利油田分公司滨南采油厂地质研究所,山东滨州256600

出　　处：《石油与天然气地质》2024年第2期486-501,共16页Oil & Gas Geology

基　　金：山东省自然科学基金项目(ZR2017QD010);国家自然科学基金项目(41702158)。

摘　　要：渤海湾盆地黄河口凹陷SC7区块滩坝是滨浅湖区的重要储集体,厘清其砂体内部结构特征对油气开发具有重要指导意义。根据现代沉积和岩心、录井、测井资料研究,对SC7区块古近系东营组二段下亚段(东二下亚段)砂体进行构型解剖,将厚泥-薄砂式滩坝划分为坝中心、坝侧缘、内缘滩、外缘滩和湖相泥5种沉积微相类型。基于厚泥-薄砂式滩坝成因和内部结构特征分析,研究了滩坝沉积特征、沉积模式和生长过程。将滩坝构型分为复合砂坝、单一坝和增生体3个级别,探讨各滩坝砂体构型单元空间展布特征。提出了单一坝坝间泥岩、测井曲线特征、相对高程差和单一坝侧向相变4种识别标志。用识别标志对密井网区单一坝进行划分,分析了单一坝规模、演化过程及连通性。在单一坝内部划分出4期增生体,最终确定了4级构型界面、单一坝侧向相变和单一坝内部增生体对油气分布的影响。Beach bars in block SC7 of the Huanghekou Sag,Bohai Bay Basin are identified as important reservoirs in the shore-shallow lacustrine area.Figuring out the internal structural characteristics of the beach-bar sand bodies can offer significant guidance for hydrocarbon exploitation.Based on the examination of modern analogs and data on cores and logs,we carry out architectural dissection for sand bodies in the lower submember of the 2nd member of the Dongying Formation(the Dong 2 lower submember)in block SC7,segmenting the beach-bar facies featuring thick mudstones and thin sandstones to five sedimentary microfacies:bar center,bar lateral margin,inner marginal beach,outer marginal beach,and lacustrine mud.By analyzing the origin and internal structural characteristics of the thick-mudstone and thinsandstone beach bars,we investigate the sedimentary characteristics and pattern and growth process of the beach bars.Consequently,the beach-bar architectures are categorized into three levels,namely composite sand bar,single bar,and accretionary body,along with the exploration of the spatial distributions of these architectural units of beach bars.To identify single bars,we propose four indicators:inter-bar mudstone,logging curve characteristics,relative elevation difference,and lateral phase change of a single bar.Using these indicators,we identify single bars in the area with a dense well pattern,analyzing their scales,evolution process,and interconnectivity.Furthermore,four phases of accretionary bodies within single bars are determined,finally ascertaining the effects of 4th-level architectural interfaces,single-bar lateral phase change,and accretionary bodies within single bars on hydrocarbon distribution.

关 键 词：单一坝分布规律 构型解剖 沉积微相 滩坝 东营组 黄河口凹陷 渤海湾盆地 

分 类 号：TE121.3[石油与天然气工程—油气勘探]