细粒碎屑岩储层基本特征及控制因素分析——以柴西茫崖地区新生代为例  

Analysis of the Basic Characteristics and Controlling Factors of Finegrained Clastic Rock Reservoirs:A case study of the Cenozoic in the Mangya area,western Qaidam Basin

作　　者：张世铭[1,2] 张小军[1,2] 张婷静[1,2] 朱军 郑永仙 易定红[1,2] 霍鹏 伏珏蓉 ZHANG ShiMing;ZHANG XiaoJun;ZHANG TingJing;ZHU Jun;ZHENG YongXian;YI DingHong;HUO Peng;FU JueRong(Research Institute of Petroleum Exploration&Development-Northwest(NWGI),PetroChina,Lanzhou 730020,China;Key Laboratory of Reservoir Description,CNPC,Lanzhou 730020,China;Research Institute of Exploration&Development of Qinghai Oilfield Company,CNPC,Dunhuang,Gansu 736202,China;No.1 Oil Production Plant of Qinghai Oilfield Company,CNPC,Haixi,Qinghai 817500,China)

机构地区：[1]中国石油勘探开发研究院西北分院,兰州730020 [2]中国石油天然气集团公司油藏描述重点实验室,兰州730020 [3]中国石油青海油田分公司勘探开发研究院,甘肃敦煌736202 [4]中国石油青海油田分公司采油一厂,青海海西817500

出　　处：《沉积学报》2023年第2期633-645,共13页Acta Sedimentologica Sinica

基　　金：国家自然科学基金项目(42172169);国家重大科技专项(2016ZX05003-006);中国石油重大科技专项(2016E-0101)。

摘　　要：采用岩心观察描述、样品薄片鉴定、激光共聚焦孔缝扫描、X衍射成分分析及扫描电镜观察等技术,对柴达木盆地新生代湖相细粒碎屑岩储层的沉积特征、储层特征、成岩作用及成岩阶段进行研究,明确了茫崖地区浅层和中深层两套细粒碎屑岩优质储层的成因及控制因素。结果表明:茫崖地区的细粒碎屑岩发育的沉积环境主要为滨浅湖滩坝和灰泥坪,具有相带变化快、岩石成分混杂、杂基含量高的特点。细粒沉积岩以低孔特低渗储层为主,浅层物性相对较好,发育残余粒间孔、粒间溶孔及黏土矿物晶间孔,具有分散分布以较粗孔喉为主和相对集中分布以连通微细孔喉为主两类孔喉组合;深层较致密,局部发育粒间溶孔,为相对集中分布的微细孔喉组合。影响储层发育的成岩作用主要为压实作用,两期碳酸盐岩胶结及溶蚀作用;其中压实作用控制浅层残余粒间孔的发育,早期的方解石胶结物抑制了压实作用,同时也是后期溶蚀发育的主要部位;溶蚀作用主要为浅层酸性流体在粒间孔基础上的溶蚀,是形成优质储层的关键。The sedimentary characteristics,basic characteristics of the reservoir,diagenesis and diagenetic stages of the Cenozoic lacustrine fine-grained clastic rock reservoirs in the Qaidam Basin were studied by core observation de⁃scription,thin section identification,laser confocal pore scanning,X-ray diffraction component analysis,SEM obser⁃vation and other technologies.Genesis and controlling factors of high-quality fine-grained clastic rock reservoirs in the shallow and medium⁃deep layers were clarified.It was found that the sedimentary environment in which the finegrained clastic rocks in the Mangya area were developed were beach-bar and mudflat in shore-shallow lake,in a rap⁃idly changing zone,with mixed rock composition and high matrix content.The reservoirs mainly have ultra-low porosi⁃ty and ultra-low permeability.The physical properties in the shallow layer are relatively good,with residual intergrain pores,intergrain dissolved pores and intercrystal pores in clay minerals,with two types of pore throat combinations:one type has scattered,relatively coarse pore throats,and the other type is relatively concentrated interconnecting fine pore throats.The deep layer is tight,with locally developed intergrain dissolved pores,and a relatively concen⁃trated combination of fine pores and throats.The diagenesis affecting reservoir development is mainly compaction,dissolution and two-stage carbonate cementation.Compaction influenced the development of shallow residual inter⁃grain pores.Early-stage calcite cement inhibited the compaction effect,and calcite cement is also the main constitu⁃ent of late dissolution.The dissolution forming intergrain pores is due mainly to the action of shallow acidic fluids.Dis⁃solution is the key to forming high-quality reservoirs.

关 键 词：柴达木盆地 茫崖地区 新生代 细粒碎屑岩储层 滨浅湖滩坝 

分 类 号：P618.13[天文地球—矿床学]