塔里木盆地柯坪—巴楚地区肖尔布拉克组储层特征与主控因素  

The characteristics and main controlling factors of dolostone reservoir in Lower Cambrian Xiaoerbulak Formation in Keping-Bachu area,Tarim Basin,NW China

作　　者：王珊[1] 曹颖辉[1] 杜德道[1] 王石[2] 李洪辉[1] 董洪奎 严威[3] 白莹[1] Wang Shan;Cao Ying-hui;Du De-dao;Wang Shi;Li Hong-hui;Dong Hong-kui;Yan Wei;Bai Ying(PetroChina Research Institute of Petroleum Exploration ＆ Development,Beijing 100083,China;SINOPEC Petroleum Exploration and Development Research Institute,Beijing 100083,China;Tarim Oil field Company,PetroChina,Korla 841000,China)

机构地区：[1]中国石油勘探开发研究院地质所,北京100083 [2]中国石化石油勘探开发研究院,北京100083 [3]中国石油塔里木油田分公司,新疆库尔勒841000

出　　处：《天然气地球科学》2018年第6期784-795,共12页Natural Gas Geoscience

基　　金：国家科技重大专项"塔里木盆地奥陶系-前寒武系碳酸盐岩油气资源潜力及目标优选"(编号:2016ZX05004-004)资助

摘　　要：中下寒武统是塔里木盆地重要的勘探领域,具备良好的勘探前景。柯坪—巴楚地区寒武系盐下储盖配置优越,中寒武统膏盐岩盖层分布稳定,是否存在规模储层是盐下勘探的关键问题之一。基于野外露头观测、岩心薄片观察、地震资料分析等,对柯坪—巴楚地区肖尔布拉克组沉积相和储层进行了研究,明确了其沉积环境、储层特征、储层主控因素及分布规律。塔里木盆地柯坪—巴楚地区在肖尔布拉克组沉积时期为内缓坡沉积环境,肖下段主要发育低能微生物坪相沉积,肖上段发育高能滩相沉积。储集岩主要包括颗粒云岩、微生物白云岩。其中颗粒云岩以鲕粒云岩、砂屑云岩以及蓝细菌有关的颗粒云岩为主;微生物白云岩以凝块石白云岩、叠层石白云岩、泡沫绵层白云岩为主。主要储集空间类型包括粒间(溶)孔、粒内(溶)孔、窗格孔、溶蚀孔洞及裂缝。高能滩相沉积是优质储层发育的物质基础,早期白云石化作用对微生物岩和颗粒云岩储层发育具有建设性作用,准同生期溶蚀作用为储层形成的关键,埋藏溶蚀作用对肖尔布拉克组储集空间具有改造作用。高能滩相优质储层在研究区大面积分布,总体平行于沉积相带。The Lower Cambrian is a significant exploration area in Tarim Basin and has good exploration prospects.Keping-Bachu area of Cambrian Subsalt has superior reservoir-cap rock assemblage and the Middle Cambrian gypsum cap rock spreads steadily.The existence of large scale carbonate reservoir is one of the critical problems in Cambrian pre-salt exploration.Based on field investigation,core description,thin section observation and seismic data analysis,the facies and characteristics as well as distribution of dolostone reservoir in Lower Cambrian Xiaoerbulak Formation in Keping-Bachu area are investigated in detail.The sedimentary environment of Keping-Bachu area in Xiaoerbulak Formation period is mainly inner ramp.Microbial flat is the dominant facies in the lower part of Xiaoerbulak Formation while grainstone shoal is the main facies in the upper part.The lithologies of dolostone reservoir include grain dolomite and microbial dolomite.The grain dolomite consists of oolitic dolomite,clastic dolomite and cyanobacteria grain dolomite while the microbial dolomite contains stromatolite,thrombolite and spongy layered dolomite.The reservoir space is composed of intergranular（dissolved）pores,intragranular（dissolved）pores,fenestral pores,dissolution caves and fractures.The main controlling factors of dolomite reservoir are proposed as follows：High-energy grainstone shoal facies are the material basis of dolostone reservoir;dolomitization plays a constructive role in the development of microbial and grain dolomite reservoir,dissolution of meteoric water in penecontemporaneous period is the key factor and burial（hydrothermal）dissolution has some rebuilding effect to the reservoir.The high quality reservoir of grainstone shoal facies is distributed in a large area in the study area,which is generally parallel to the sedimentary facies.

关 键 词：塔里木盆地 柯坪—巴楚地区 肖尔布拉克组 碳酸盐岩缓坡 储层特征及分布 

分 类 号：TE122.1[石油与天然气工程—油气勘探]