超深层碳酸盐岩层系硅质岩储层表征与评价--以塔里木盆地塔深6井为例  

Characterization and evaluation of chert reservoirs in ultra-deep carbonate rock formations-A case study on Well TS 6 in the Tarim Basin

作　　者：刘永立[1,2] 尤东华[3] 李海英[2] 高利君[2] 蒋宏[3] 张卫峰[2] 鲍芳 Liu Yongli;You Donghua;Li Haiying;Gao Lijun;Jiang Hong;Zhang Weifeng;Bao Fang(Key Laboratory of Tectonics and Petroleum Resources(Ministry of Education),China University of Geosciences,Wuhan,Hubei 430074,China;Northwest Oilfield Branch,SINOPEC,Urumqi,Xinjiang 830011,China;Wuxi Research Institute of Petroleum Geology,Petroleum Exploration and Production Research Institute,SINOPEC,Wuxi,Jiangsu 214126,China)

机构地区：[1]中国地质大学(武汉)构造与油气资源教育部重点实验室,湖北武汉430074 [2]中国石化西北油田分公司,新疆乌鲁木齐830011 [3]中国石化勘探开发研究院无锡石油地质研究所,江苏无锡214126

出　　处：《石油与天然气地质》2021年第3期547-556,共10页Oil & Gas Geology

基　　金：国家科技重大专项(2017ZX05005-002);中国石化科技部攻关项目(P15030)。

摘　　要：塔里木盆地塔深6井揭示了奥陶系蓬莱坝组发育一定厚度的硅质岩储层,其储层发育特征与油气储集性能是当前研究焦点之一。基于岩性、电性响应特征,开展了详细的岩心观察描述、X衍射、显微岩石学分析和储集性能等储层表征与评价。分析结果表明,塔深6井硅质岩储层比同层系白云岩具有更高的孔隙度,超过7400 m埋深下孔隙度平均值高达13.5%;主要由微晶石英组成,石英含量高达83.0%~93.7%,另有少量粘土、方解石和白云石等其他矿物。储集空间主要为石英晶间微孔隙,分布相对均一;孔隙直径多为1~10μm,其次为0.1~1μm,主要喉道直径为10~100μm。原油加压饱和离线核磁共振实验研究表明,0.1~10μm孔隙是硅质岩储层的主要储油空间,且总孔隙度越大可容纳的原油总量越大。塔深6井硅质岩储层与白云岩互层接触关系及与硅质结核的共生关系、显微层理结构特征、初始高孔隙度特征均表明其为沉积与成岩作用的共同产物,形成于台地内局部相对深水区。地震反射特征揭示储集体分布南北长约300 m、东西宽约200 m。硅质岩储层的发现对认识塔里木盆地早奥陶世碳酸盐岩台地内部结构差异性具有重要意义。Thick chert reservoirs were revealed by Well Tashen 6 penetrating the Ordovician Penglaiba Formation in the Tarim Basin and have been the focus of research for reservoir development characteristics and storage capacity.Based on lithology and electrical response characteristics,the reservoirs were studied with detailed core observation and description,X-ray diffraction,microscopic petrology analysis,reservoir performance and other reservoir characterization and evaluation methods.The results show that the reservoirs have higher porosity than dolostone reservoirs of the same sequence,with an average porosity as high as 13.5%at a burial depth of more than 7400 m.The reservoirs are mainly composed of microcrystalline quartz,with a content as high as 83.0%-93.7%,and a small amount of clay,calcite,dolomite and other minerals.The reservoir space is relatively uniformly distributed intercrystalline micropores in quartz crystals with a pore diameter mainly varying from 1 to 10μm,followed by 0.1-1μm,and main throat diameter ranging from 10 to 100μm.The off-line nuclear magnetic resonance of pressure saturated crude samples shows that pores of 0.1-10μm in diameter serve as the main storage space.And the greater the total porosity,the greater the total amount of crude oil that can be accommodated.The interbedded siliceous-dolomite,the micro-bedding structure,the high initial porosity and the symbiotic siliceous nodules,all indicate that the reservoirs are the co-product of sedimentation and diagenesis in relatively deep water area on the platform.Furthermore,the seismic reflection characteristics reveal that the reservoir body is about 300 m long from north to south and 200 m wide from east to west.The discovery of siliceous rock reservoirs is of great significance to understanding the internal structural differences of the Early Ordovician carbonate platform in the Tarim Basin.

关 键 词：核磁共振 蓬莱坝组 硅质岩储层 超深层碳酸盐岩储层 奥陶系 塔里木盆地 

分 类 号：TE122.2[石油与天然气工程—油气勘探]