摘要
四川盆地自流井组大安寨段陆相页岩油具有较大勘探开发前景,沉积相多样,岩性复杂且纵向变化快,岩性差异化组合模式及储层特征认识不清,制约了大安寨段页岩油储层有利层段的优选。基于川中地区4口实钻井岩心观察、薄片分析和X射线衍射(X-ray diffraction,XRD)、镜质体反射率Ro测试、总有机碳(total organic carbon,TOC)含量测试、物性测试、岩石热解、荧光分析等实验,依据矿物组成特征和介壳含量、产状、介壳层厚度及与页岩的叠置关系,建立川中地区大安寨段7种岩性组合模式(纯页岩型、页岩夹漂浮状介壳灰岩型、页岩夹毫米级介壳灰岩型、页岩夹厘米级介壳灰岩型、页岩夹分米级介壳灰岩型、页岩与介壳灰岩互层型、纯介壳灰岩型)。综合TOC、物性、含油性、脆性指数等储层特征参数,明确不同岩性组合的储层特征。结合大安寨段的勘探开发实践和储层特征,建立储层的分级评价标准,认为页岩夹毫米级介壳灰岩型和页岩夹厘米级介壳灰岩型岩性组合为最有利的源储组合,物性最好,含油饱和度指数(oil saturation index,OSI)最高,可动性强,脆性好等特征,是勘探开发的重点层段。厚层暗色页岩层段具有最高的TOC含量、较好的物性和含油性,是下步勘探的潜力层段。
The continental shale oil in the Da'anzhai section of the Ziliujing Formation in the Sichuan Basin has great exploration and development prospects.The sedimentary facies are diverse,the lithology is complex,and the vertical changes are fast.The understanding of the lithological differentiation combination mode and reservoir characteristics is unclear,which restricts the optimal selection of favorable shale oil reservoirs in the Da'anzhai section.Based on observations,thin section analysis,X-ray diffraction(XRD),vitrinite reflectance Ro testing,total organic carbon(TOC)content testing,physical property testing,rock pyrolysis,fluorescence analysis,and other experiments of four actual drilling cores in the central Sichuan Basin.By comprehensively analyzing mineral composition characteristics,as well as considering the content,occurrence,thickness of the shell layer,and its superimposed relationship with shale,seven lithological combination models for the Da'anzhai member in the central Sichuan basin were established(pure shale type,shale interbedded with floating shell limestone type,shale interbedded with millimeter scale shell limestone type,shale interbedded with centimeter scale shell limestone type,shale interbedded with centimeter scale shell limestone type,shale interbedded with shell limestone type,and pure shell limestone type).By integrating reservoir characteristic parameters such as TOC content,physical properties,oil content,and brittleness index,the reservoir characteristics of different lithological combinations were clarified.Based on the exploration and development practices of the Da'anzhai section and reservoir characteristics,a classification evaluation standard for reservoirs was established.It is believed that the lithological combination of shale interbedded with millimeter scale shell limestone and shale interbedded with centimeter scale shell limestone is the key layer for exploration and development,which has most favorable source reservoir combination,best physical properties,the highest oil saturation index(OSI)index,strong mobility,and good brittleness.The thick dark shale interval has the highest TOC content,good physical and oil properties,which is a potential interval for further exploration.
作者
朱逸青
伍秋姿
冷钇江
殷樱子
何一凡
杨一茗
张亦弛
何江
ZHU Yi-qing;WU Qiu-zi;LENG Yi-jiang;YIN Ying-zi;HE Yi-fan;YANG Yi-ming;ZHANG Yi-chi;HE Jiang(Southwest Oil&Gasfield Company,PetroChina,Chengdu 610501,China;Shale Gas Evaluation and Exploitation Key Laboratory of Sichuan Province,Chengdu 610051,China;School of Earth Science and Technology,Southwest Petroleum University,Chengdu 610500,China)
出处
《科学技术与工程》
北大核心
2025年第20期8392-8403,共12页
Science Technology and Engineering
基金
中国石油-西南石油大学创新联合体项目(2020CX020000)
中国石油西南油气田-西南石油大学校企合作项目(2023-13094)。
关键词
岩性组合
储层特征
储层分级标准
页岩油
大安寨段
lithological combination
reservoir characteristic
reservoir classification standard
shale oil
Da'anzhai section
