南海惠州凹陷三角洲-陆架环境地质模式认识  

Geological model of delta-shelf environment in Huizhou Sag in South China Sea

作　　者：涂志勇 谢明英 冯沙沙 陈一鸣 TU Zhiyong;XIE Mingying;FENG Shasha;CHEN Yiming(Research Institute of CNOOC(China)Co.,Ltd.,Shenzhen Branch,Shenzhen Guangdong 518054,China)

机构地区：[1]中海石油(中国)有限公司深圳分公司研究院,广东深圳518054

出　　处：《石油化工应用》2023年第4期83-88,共6页Petrochemical Industry Application

基　　金：中国海油重大科技专项“复杂海相砂岩油藏挖潜关键技术研究”,项目编号:CNOOC-KJ135ZDXM37SZ03SZ。

摘　　要：南海珠江口盆地惠州凹陷发育三角洲-陆架沉积体系,由于受到北部古珠江三角洲和东南部东沙隆起的双重物源影响,岩相组合以及沉积类型多样化,低渗储层较为发育,但目前在储层沉积和砂体地质模式方面缺乏系统认识。利用薄片鉴定、测井岩相定量识别、层序地层分析、地震沉积学等方法,分析了珠海组及珠江组纵向约1000 m三角洲-陆架沉积砂体的发育模式及特征。划分了中渗中粗砂岩相、低渗钙质砂岩相、低渗泥质砂岩相、低渗细粉砂岩相、低渗中粗砂岩相以及泥岩相六类岩相,建立了岩相定量识别图版。在此基础上将研究层段划分为厚层中粗砂岩段、砂泥互层中粗砂岩段和大套泥岩夹薄层砂岩段三元沉积序列,构成了一个粒度逐渐向上变细的正旋回沉积。厚层中粗砂岩段主要目标为发育一定溶蚀孔隙,且顶部发育一定泥岩封堵的砂层;水下三角洲前缘砂泥互层沉积,组成了较好的储盖组合,利于油气藏形成。大套泥岩夹薄层砂岩段砂体以透镜状孤立发育于厚层陆架泥中,是岩性油气藏勘探开发的有利目标。The delta-shelf sedimentary system is developed in Huizhou Sag of the Pearl River Mouth Basin in South China Sea.Influenced by the dual provenance of the ancient Pearl River Delta in the north and the Dongsha uplift in the southeast,the lithofacies assemblage and sedimentary types are diversified,and the low permeability reservoirs are relatively developed.However,there is a lack of systematic understanding of reservoir sedimentation and sand body geological model.The development patterns and characteristics of delta-shelf sedimentary sand bodies,which are about 1000 meters in Zhuhai and Zhujiang formation's longitudinal direction,are analyzed by means of thin section identification,quantitative identification of well logging lithofacies,sequence stratigraphic analysis and seismic sedimentology.Six types of lithofacies can be identified and divided,medium permeability medium coarse sandstone facies,low permeability calcareous sandstone facies,low permeability argillaceous sandstone facies,low permeability fine sandstone facies,low permeability medium coarse sandstone facies and mudstone facies,and the lithofacies quantitative identification chart is established.On this basis,the study interval is divided into three sets of sedimentary sequences,thick medium coarse sandstone section,sand mud interbedded medium coarse sandstone section and large mudstone interbedded with thin sandstone section,which constitute a normal cycle sediment with gradually finer grain size.The main exploration target in thick medium coarse sandstone section is a thick sand layer with strong dissolution,and a certain amount of mudstone plugging is developed on the top.Sand mud interbedded sediment of submerged delta front,forming a good reservoir cap combination,is conducive to the formation of oil and gas reservoirs.The sand body in the large mudstone interbedded with thin sandstone section is isolated and developed in thick shelf mud in lenticular shape,which is favorable target for exploration and development of lithologic oil-gas reserv

关 键 词：低渗储层 地质模式 三角洲-陆架环境 惠州21地区 

分 类 号：TE121.34[石油与天然气工程—油气勘探]