渤海湾盆地沾化凹陷沙四上亚段湖相碳酸盐岩储层特征及其控制因素  

CHA RACTERISTICS AND CONTROLLING FACTORS OF LACUSTRINE CAR-BONATE R ESERVOIRS IN THE UPPER FOURTH MEMBER OF SHA HEJIE FORMATION IN THE ZHANHUA SAG,BOHAI BAY BASIN

作　　者：何青 杨田 苏朝光[2] 巴素玉[2] 金杰华 蔡来星 任启强 HE Qing;YANG Tian;SU Chaoguang;BA Suyu;JIN Jiehua;CAI Laixing;REN Qiqiang(Institute of Sedimentary Geology,Chengdu Univerisity of Technology,Chengdu,Sichuan 610059,China;Institute of Geophysical Exploration,Shengli Oilfield Com pany,Sinopec,Dongying,Shandong 257022,China)

机构地区：[1]成都理工大学沉积地质研究院,四川成都610059 [2]中国石化胜利油田分公司物探研究院,山东东营257022

出　　处：《矿物岩石》2023年第3期144-156,共13页Mineralogy and Petrology

基　　金：自然资源部沉积盆地与油气资源重点实验室开放基金(项目编号:cdcgs2020003);国家自然科学基金(项目批准号:42072126)。

摘　　要：沾化凹陷是渤海湾盆地济阳坳陷重要的油气勘探区,其湖相碳酸盐岩油藏是关键的勘探目标,但前期研究对该类储层关注较少。为进一步认识沾化凹陷湖相碳酸盐岩储层特征与控制因素,以沙四上亚段湖相碳酸盐岩储层为研究对象,综合利用岩石学、物性表征、地球化学等多种方法,系统描述了碳酸盐岩储层的物质组成、储集物性、储集空间、孔喉结构、成岩作用等特征。结果表明:沾化凹陷碳酸盐岩以灰岩为主,孔隙度分布在0.03%~35.20%之间,平均孔隙度为6.90%,渗透率分布在0.0002×10^(-3)μm^(2)~1707.9200×10^(-3)μm^(2),平均渗透率为16.60×10^(-3)μm^(2),为典型的中一低孔隙度低渗透储层;储集空间包括原生孔隙、次生孔隙和裂缝,以次生孔隙为主,发育3种类型孔喉结构。研究区内储层破坏性成岩作用包括压实作用、方解石胶结、白云石胶结、硬石膏胶结等;溶蚀作用为主要的建设性成岩作用,能有效地提高储层储集性能。高能沉积相带中灰礁相、灰滩相储层物性较好,低能沉积相带中灰泥坪相物性普遍较差;裂缝的发育是研究区部分低孔隙度高渗透率储层形成的主要原因;在沉积作用基础上成岩作用进一步改造储层,使其物性优劣分异更加显著。Zhanhua Sag is an oil and gas exploration area in Jiyang Depression,Bohai Bay Basin,with the lacustrine carbonate reservoir as a key exploration target,but the previous research has paid little attention to this kind of reservoir.In this paper,the lacustrine carbonate reservoir in the upper submember of Es4 is taken as the research object,and the material composition,reservoir physical property,reservoir space,pore throat structure and diagenesis of the carbonate reservoir are systematically studied through comprehensive descriptions of petrology;physical characterization and geochemistry so as to unravel the characteristics and controlling factors of lacustrine carbonate reservoir in Zhanhua Sag.The results show that the carbonate rocks in Zhanhua Sag are mainly limestone,with the porosity ranging from 0.03%to 35.20%(average 6.90%),and with the permeability ranging from 0.0002×10^(-3)μm^(2)to 1707.9200×10^(-3)μm^(2)(average 16.60×10^(-3)μm^(2)),belonging to the typical medium-low porosity and low permeability reservoir.The reservoir space consists of primary pores,secondary pores and fractures,with the secondary pore as the dominant type.Meanwhile,three types of pore throat structures are developed in the reservoir.The destructive diagenesis of reservoir in the study area includes compaction,calcite cementation,dolomite cementation,anhydrite cementation,etc.,while dissolution is the main constructive diagenesis,which can effectively improve the reservoir storage performance.The study reveals that the lime reef facies and lime beach facies in the high-energy sedimentary facies possess good physical properties,while the lime mud flat facies in the low-energy sedimentary facies generally display poor physical properties.The development of fractures is the main reason for the formation of some low porosity and high permeability reservoirs in the study area.It is proposed that the diagenesis on the basis of sedimentation has further transformed the reservoir,making the difference of its physical properties even

关 键 词：储层特征 控制因素 湖相碳酸盐岩 沙四上亚段 沾化凹陷 

分 类 号：P624[天文地球—地质矿产勘探]