基于连续薄片统计的须二段岩石相组合及沉积旋回分析  

Analysis of lithofacies assemblage and sedimentary cycle of the second member of Xujiahe Formation based on continuous thin section statistics

作　　者：王贵华 林小兵[1,2] 刘莉萍[3] 田景春[1,2] 郑宇超 柳远松 余文杰 WANG Guihua;LIN Xiaobing;LIU Liping;TIAN Jingchun;ZHENG Yuchao;LIU Yuansong;YUWenjie(Institute of Sedimentary Geology,Chengdu University of Technology,Chengdu 610059,China;State Key Laboratory of Oil&Gas Reservoir Geology and Development Engineering,Chengdu University of Technology,Chengdu 610059,China;Exploration and Development Research Institute of Southwest Oil&Gas Company,SINOPEC,Chengdu 610041,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]成都理工大学“油气藏地质及开发工程”全国重点实验室,四川成都610059 [3]中国石化西南油气分公司勘探开发研究院,四川成都610041

出　　处：《复杂油气藏》2024年第1期29-37,共9页Complex Hydrocarbon Reservoirs

基　　金：国家自然科学基金“致密砂岩含F成岩流体地球化学演化与硅质碎屑颗粒溶蚀机制”(42172135)。

摘　　要：目前对川西地区三叠系须家河组二段(须二段)已开展了沉积微相层面研究,但不同微相背景下岩石相特征与沉积旋回存在差异。为了更加精细刻画岩石相特征并揭示其对有利储层的指示意义,基于连续岩屑及岩心薄片鉴定的岩石学特征分析,通过地质学手段及聚类分析技术,结合测井数据等资料,建立须二段更精细的物质组成、岩石相类型及沉积微相演化序列。须二段砂体划分为六个岩石相,并识别出16个水下分流河道-分流间湾、水下分流河道-河口坝沉积旋回。统计显示水下分流河道下部的A1类岩石相、A4类岩石相物性较好,因此水下分流河道的下部物性通常高于上部,且普遍优于河口坝。须二段中亚段物性最好,上亚段次之,下亚段较差。水下分流河道物性普遍比河口坝好;物性变化与旋回、岩石相的变化存在一定的相关性;发育于水下分流河道中下部的A1、A4类岩石相更易形成有利储层。At present,the study of sedimentary microfacies has been carried out on the second member of the Triassic Xujiahe Formation(Xu2 member)in the western Sichuan region,but there are differences in the rock facies characteristics and sedimentary cycles under different microfacies backgrounds.To more accurately characterize the rock facies characteristics,it is indicative significance for favorable reservoirs.Based on the petrological characteristics of continuous cuttings and core thin sections identification,a more precise sequence of material composition,rock facies type,and sedimentary microfacies evolution is established in the Xu2 member using geological methods and cluster analysis techniques,combined with well-logging data and other information.The sand body in the Xu2 member can be divided into 6 rock facies,and 16 sedimentary cycles of underwater distributary channel-inter distributary bay and underwater distributary channel-estuarine bar are identified.Statistics show that the lower part of the underwater distributary channel has better physical properties in rock facies A1 and A4,so the physical properties of the lower part of the underwater distributary channel are usually higher than those of the upper part and are generally better than those of estuary dam.The physical properties of the middle subsegment in the second section are the best,followed by the upper subsegment and the lower subsegment.The physical properties of underwater distributary channels are generally better than those of estuarine dams.A certain correlation exists between the changes in physical properties and cycle and rock facies.A1 and A4 rock facies developed in the middle and lower part of underwater distributary channels are more likely to form favorable reservoirs.

关 键 词：聚类分析 物质组成 岩石相组合 沉积旋回 须家河组二段 川西地区 

分 类 号：TE132[石油与天然气工程—油气勘探]