多物源体系下砂砾岩储层差异性孔隙演化模式——以车镇凹陷沙三段、沙四段为例  

Differential evolution model of porosity in glutenite reservoirs under multi-provenance systems:Taking a case study of Es_(3) and Es_(4) of Chezhen Sag

作　　者：康玉柱[1] 张金亮 徐耀辉[3] 李阳[3] KANG Yuzhu;ZHANG Jinliang;XU Yaohui;LI Yang(Research Institute of Petroleum Exploration&Development,SINOPEC,Beijing 100083;Faculty of Geographical Science,Beijing Normal University,Beijing 100875;Hubei Key Laboratory of Petroleum Geochemistry and Environment(Yangtze University),Wuhan 430100,Hubei)

机构地区：[1]中国石化石油勘探开发研究院,北京100083 [2]北京师范大学地理科学学部,北京100875 [3]油气地球化学与环境湖北省重点实验室(长江大学),湖北武汉430100

出　　处：《长江大学学报（自然科学版）》2023年第5期1-20,共20页Journal of Yangtze University(Natural Science Edition)

基　　金：中国博士后科学基金项目“中深层砂砾岩储层微观孔隙结构与差异性成岩成藏演化的响应机制研究”(2021M700537);非常规油气省部共建协同创新中心(长江大学)开放基金项目“致密砂砾岩储层微观孔隙结构量化表征及其与差异性成岩演化、烃类充注的响应机制研究”(UOG2022-11)。

摘　　要：随着勘探程度及勘探技术的不断提高,断陷盆地砂砾岩储层已成为隐蔽油气藏的重要勘探目标之一。位于渤海湾盆地济阳坳陷北部的车镇凹陷作为典型的陆相断陷凹陷,其砂砾岩储层的孔隙演化模式的研究对该区隐蔽油气藏勘探具有重要意义。基于岩心观察、薄片鉴定、扫描电镜分析,将车镇凹陷沙河街组三段、四段(以下简称沙三段、沙四段)砂砾岩储层分布区划分为碳酸盐岩物源区、碳酸盐岩变质岩混合物源区、变质岩物源区和不稳定物源区4种类型。孔隙演化历史和演化模式研究表明,物源类型控制了储层岩石的抗压实程度,决定了储层的初始孔隙度。整个凹陷内储层孔隙度的减少主要受压实作用控制,碳酸盐物源区的陡坡带压实作用最强。碳酸盐岩变质岩混合物源区的陡坡带和洼陷带少部分储层的胶结作用是孔隙度减少的主控因素,其缓坡带储层的压实作用和胶结作用均弱于陡坡带和洼陷带。碳酸盐岩物源区的陡坡带和洼陷带储层处于封闭体系下,溶蚀作用主要控制了储集空间类型的调整和重新分配,其净增孔隙度有限。碳酸盐岩变质岩混合物源区及变质岩物源区储层抗压实作用较强,溶蚀作用减缓了储层孔隙度的降低。不稳定物源区储层处于相对开放的成岩环境中,溶蚀作用可有效改善储层孔隙度,局部较强的溶蚀作用和超压导致的储层裂缝是异常孔渗带发育的重要控制因素。With the continuous improvement of exploration degree and technology,glutenite reservoirs in faulted basin have become one of the important exploration targets for subtle oil and gas reservoirs.The Chezhen Sag,located in the north of Jiyang Depression in Bohai Bay Basin,is a typical continental faulted sag,and the study on the porosity evolution model of its glutenite reservoirs is of great significance to the exploration of subtle oil and gas reservoirs.Based on core observation,thin section identification and scanning electron microscope analysis,the distribution division of the third and fourth member of Shahejie Formation(hereinafter referred to as Es_(3) and Es_(4))in Chezhen Sag can be divided into four types:carbonate provenance,carbonate-metamorphic mixture provenance,metamorphic provenance and unstable provenance.The study of the history and model of porosity evolution shows that the provenance types control the compaction resistance degree of reservoir rocks and determine the initial porosity of the reservoirs.The reduction of reservoir porosity in the whole sag is mainly controlled by compaction,and the steep slope zone with carbonate provenance has the strongest compaction.The cementation of a few reservoirs in the steep slope zone and sub-sag zone with carbonate-metamorphic mixture provenance dominates the reduction of porosity.The compaction and cementation of reservoirs in gentle slope zone are weaker than those in steep slope zone and sub-sag zone.The reservoirs in steep slope zone and sub-sag zone with carbonate provenance are in a closed system,and the dissolution mainly controls the adjustment and redistribution of the reservoir space types,while the net porosity increased by dissolution is limited.The compaction resistance of the reservoirs in the mixture provenance and metamorphic provenance is stronger,and the dissolution slows down the reduction of reservoir porosity.The reservoirs in the unstable provenance are in a relatively open diagenetic environment,where the dissolution can effective

关 键 词：多物源体系 砂砾岩储层 孔隙演化 车镇凹陷 

分 类 号：TE122.23[石油与天然气工程—油气勘探]