川东地区须四段致密砂岩储层特征与主控因素  

CHARACTERISTICSSAND MAIN CONTROLLING FACTORSSOFTIGHT SANDSTONE RESERVOIR IN THE 4TH SEGMENT OF THE XUJIAHE FORMATION,EASTERN AREA OF SICHUANBASIN

作　　者：黎李 朱宜新[1] 刘孟琦 呼唤 雍伟 郑超 李富祥 徐胜林[2,3] LI Li;ZHU Yixin;LIU Mengqi;HU Huan;YONG Wei;ZHENG Chao;LI Fuxiang;XU Shenglin(Chongqing Gas Field,PetroChina Southzwest Oil and Gas Field Com pany,Chongqing 400021,China;State Key Laboratory of Oil and Gas Reservoir Geology and Erploitation,Chengdu,Sichuan 610059,China;Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu,Sichuan 610059,China;Erploration and Development Research Institute,PetroChina Southwest Oil&Gasfield Com pany,Chengdu,Sichuan 610041,China)

机构地区：[1]中国石油西南油气田分公司重庆气矿,重庆400021 [2]油气藏地质及开发工程国家重点实验室成都理工大学,四川成都610059 [3]成都理工大学沉积地质研究院,四川成都610059 [4]中国石油西南油气田公司勘探开发研究院,四川成都610041

出　　处：《矿物岩石》2024年第3期142-151,共10页Mineralogy and Petrology

基　　金：国家自然科学基金面上基金项目(批准号:42172132)。

摘　　要：四川盆地须家河组是致密油气勘探的重要层位,已有研究集中于川西-川中地区,但对川东地区须家河组须四段研究较少,其储集层基本特征及控制因素不清楚,不利于后续的相关研究与油气勘探实践。本次研究基于野外剖面和钻井岩心样品,对普通薄片分析、铸体薄片分析和扫描电镜进行分析,并结合孔隙度与渗透率分析数据,开展川东地区须四段储集岩岩石学特征、孔隙特征和物性特征及储层发育主控因素分析。研究表明川东地区须四段储集砂岩主要为中-粗粒长石石英砂岩和岩屑石英砂岩,孔隙度主体分布于2%~8%(均值5.11%),砂岩渗透率分布于(0.01~0.10)×10^(-3)μm^(2),属于致密砂岩储层。成岩作用与沉积作用是储层孔隙度共同影响了储集层物性,但成岩作用起主导性作用。储集砂岩原始孔隙度34.58%,成岩压实作用导致了原始孔隙减少28.33%~6.25%;胶结作用进一步促使孔隙度减少为3.33%;长石、岩屑等溶蚀作用为主要增孔因素,导致储集砂岩增加孔隙1.78%,上述成岩作用综合导致了研究区须四段致密砂岩储层的形成。发育于主河道的中-粗粒砂岩孔隙度均值为6.67%,具有最好的物性,河口坝和席状砂微相的砂岩次之,孔隙度均值为6.1%,分流间湾微相砂岩物性最差,孔隙度均值为3.53%。上述研究成果为致密砂岩储层研究与油气勘探提供了借鉴与支撑。The Xujiahe Formation in the Sichuan Basin serves as a crucial reservoir for tight oil and gas exploration.However,while previous studies have mainly focused on the western-central area of the Si-chuan Basin,the 4th segment of the Xujiahe Formation(Tsr')in the eastern area has received little atten-tion.In particular,understanding its basic reservoir characteristics and controlling factors has remained unclear,thus impeding subsequent research and oil and gas exploration efforts.Through field cross-sec-tion studies and analysis of drilling core samples,rock thin sections,cast thin sections,and scanning elec-tron microscopy,this research delves into the petrology characteristics,pore characteristics,physical characteristics,and primary controlling factors of reservoir development in Tgt in the eastern area of the Sichuan Basin.The findings reveal that the Tg'reservoir sandstone in the eastern area mainly comprises medium-coarse-grained feldspar quartz sandstone and lithic quartz sandstone,characterized by a porosity ranging from 2%to 8%(averaging 5.11%)and permeability of(0.01-0.10)×10^(-3)μm^(2),indicativeof a tight sandstone reservoir.While both diagenesis and sedimentation influence the physical properties of the reservoir,diagenesis is the primary determinant.The original porosity of the T,'reservoir sandstone is 34.58%,with diagenetic compaction reducing it to 6.25%,and cementation further diminishing it to 3.33%.Feldspar and clast dissolution emerge as the primary pore-increasing factors,resulting in a i.78%increase in pore volume of the reservoir sandstone.The amalgamation of these diagenetic processes under-lies the formation of the Tg.rt tight sandstone reservoir.In the study area,medium-coarse-grained sand-stone developed in the primary channel exhibits the most favorable physical properties,with an average porosity of 6.67%.Estuarine bar and sheet sand microfacies sandstone rank second,with an average po-rosity of 6.1%.Conversely,microfacies sandstone in interdistributary bays exhibits poor physical p

关 键 词：储层特征 主控因素 须家河组四段 川东地区 

分 类 号：TE122[石油与天然气工程—油气勘探] P534.51[天文地球—古生物学与地层学]