川西坳陷中段须四段储层综合评价  

Comprehensive evaluation of reservoir in the forth Member of Xujiahe Formation in the Middle Area of Western Sichuan Depression

作　　者：陈贤良[1] 纪友亮[2] 杨克明[3] CHEN Xianliang;JI Youliang;YANG Keming(College of Geology and Environment,Xi’an University of Science and Technology,Xi’an 710054,China;State Key Laboratory of Petroleum Resources and Prospecting,China University of Petroleum,Beijing 102249,China;Research Institute of Exploration and Development,Southwest Oil&Gas Company,SINOPEC,Chengdu 610016,China)

机构地区：[1]西安科技大学地质与环境学院,陕西西安710054 [2]中国石油大学(北京)油气资源与探测国家重点实验室,北京102249 [3]中国石化西南油气分公司勘探开发研究院,四川成都610016

出　　处：《西安科技大学学报》2022年第4期760-767,共8页Journal of Xi’an University of Science and Technology

基　　金：国家自然科学基金青年项目(41602212);陕西省教育厅科学研究计划项目(18JK0519)。

摘　　要：川西坳陷须家河组是典型的致密砂岩储层,勘探的首要目标是在致密背景下寻找相对高渗区,成岩相是现今储层面貌及品质的直接反映。针对川西坳陷中段须四段砂岩储层,利用岩石薄片、铸体薄片、阴极发光、扫描电镜等分析测试方法,开展定量成岩相储层综合评价。结果表明:须四段储层岩石类型以中粒岩屑砂岩和岩屑质石英砂岩为主,孔隙类型以粒内溶孔和粒间溶孔为主,孔隙结构为微-细孔、微-细喉型,孔隙度、渗透率低,属致密储层;基于压实、胶结、溶蚀等3种主要成岩作用强度计算结果和分级标准,须四段储层以中强-强压实、强胶结、弱溶蚀为主要特征,发育6种主要成岩相类型且下亚段压实与胶结强度高于上亚段、溶蚀强度弱于上亚段。结合沉积相、储集空间类型及储层物性特征等将须四段储层划分为4类,其中Ⅱ类储层为有利储层,分布在中江-洛带地区和新场构造带。研究成果可为进一步研究致密气提供地质依据。The Xujiahe Formation is a typical tight sandstone reservoir in the Western Sichuan Depression.The primary goal of further exploration is to find relatively high-permeability areas under tight conditions.Diagenetic facies might well reflect the present reservoir appearance and quality.Therefore, aiming at the sandstone reservoir of the fourth member of the Xujiahe formation in the middle area of the western Sichuan Depression, a comprehensive reservoir evaluation was carried out based on quantitative diagenetic facies research by using petrographic thin sections, casting thin sections, cathodoluminescence, scanning electron microscopy and other analytical methods.The results show that reservoir rock types of the forth member of Xujiahe formation are mainly medium-grained lithic sandstone and lithic quartz sandstone.The pore types are mainly intragranular dissolved pores and intergranular dissolved pores and the pore structure is micro-fine pores and micro-fine throat type, and their porosity and permeability are low, belonging to tight reservoir.Based on the calculation results and three classification standards of compaction, cementation and dissolution, the reservoir of the fourth member of the Xujiahe formation are characterized by strong compaction, strong cementation and weak dissolution.Furthermore, six major diagenetic facies types were classified, and the compaction and cementation degree of the lower sub-member is higher than that of the upper sub-member, and the degree of dissolution is weaker than that of the upper sub-member.Based on quantitative diagenetic facies, with sedimentary facies in view, reservoir space type and reservoir physical properties, the reservoir was divided into four types, and Type II is a favorable reservoir in the study area, which mainly distributed in the Xinchang tectonic belt and Zhongjiang-Luodai area.The research results can provide geological basis for further exploration and development of tight gas in the study area.

关 键 词：川西坳陷中段 须四段 定量成岩相 储层评价 有利储层 

分 类 号：P624[天文地球—地质矿产勘探]