摘要
桂中坳陷北部鹿寨组海相富有机质页岩是滇黔桂盆地页岩气勘探的重要接替领域,目前在勘探初期已取得重大突破,因此开展地质-工程一体化的评价工作极为关键。利用岩心、薄片和扫描电镜等岩石物理实验和常规、成像、核磁共振及阵列声波等测井资料,在岩心刻度测井和小层精细划分的基础上,分别开展了地质和工程“甜点”要素测井表征研究。通过对烃源岩品质、储层品质和工程品质叠合,最终完成了地质-工程“双甜点”的耦合与优选。研究表明:鹿寨组一段页岩岩性以硅质页岩、混合质页岩和灰质页岩3种类型为主。孔渗物性偏低,w(TOC)介于1%~2%之间。生物硅含量低,硅质来源主要为陆源碎屑供给,页岩气主要赋存在黏土矿物相关孔隙和微裂缝中,且以吸附气为主而游离气较少。脆性指数介于20%~80%之间,且基本均大于40%。应力差异系数介于0.26~0.50,现今最大水平主应力方向为NNE-SSW方向。优选③小层底部页岩“甜点”层段作为水平井靶窗,水平段实钻气测结果显示良好。研究成果能够为页岩气单井“甜点”测井评价与水平井靶窗优选提供理论指导和方法支撑。
[Objective]The marine organic-rich shale of the Luzhai Formation of the northern Guizhong Depression is an important replacement field for shale gas exploration in the Dian-Qian-Gui Basin.At present,great breakthroughs have been made in the initial stage of exploration.So it is very important to evaluate the geological-engineering integration.[Methods]In this study,petrophysical data(e.g.,core,thin section and scanning electron microscopy data)and logging data(e.g.,conventional,imaging,nuclear magnetic resonance and array acoustic)are used to study the logging characteristics of geological and engineering"sweet spots"on the basis of core calibration logs and fine delineation of small layers,respectively.By superimposing the hydrocarbon source rock quality,reservoir quality and engineering quality,the coupling and optimization of geological and engineering"double sweet spots"are finally completed.[Results]The results show that the lithology of the shale in the first member of the Luzhai Formation is dominated by three types:siliceous shale,mixed shale and gray shale.The organic matter abundance and pore permeability are low,and the TOC content is between 1%and 2%.The biogenic silica content is low,and the source of silica is mainly the land source of debris supply.Shale gas is mainly stored in the pore spaces and microfractures associated with clay minerals,and adsorbed gas is the main source,while the free gas content accounts for a small proportion.The brittleness index ranges from 20%to 80%and is basically greater than 40%.The stress coefficient of variation ranges from 0.26 to 0.50,and the direction of the present maximum horizontal in situ stress is NNE-SSW.[Conclusion]The shale"sweet spot"section at the bottom of the third small layer was selected as the target window of the horizontal well,and the results of horizontal section drilling and gas measurement showed good results.The research results can provide theoretical guidance and methodological support for the evaluation of"sweet spot"logging and the selection of horizontal well target windows for shale gas wells.
作者
钟敏
黄玉越
覃英伦
陈康军
王贵文
卓色强
毕少琛
陆文师
康海晶
党文乐
赖锦
ZHONG Ming;HUANG Yuyue;QIN Yinglun;CHEN Kangjun;WANG Guiwen;ZHUO Seqiang;BI Shaocheng;LU Wenshi;KANG Haijing;DANG Wenle;LAI Jin(China Guangxi Investment Group Energy Group Co.,Ltd.,Nanning 530000,China;College of Geosciences,China University of Petroleum(Beijing),Beijing 102249,China;Development Division of Southwest Oil and Gasfield Company,PetroChina,Chengdu 610017,China)
出处
《地质科技通报》
CAS
CSCD
北大核心
2024年第4期113-127,共15页
Bulletin of Geological Science and Technology
基金
广西壮族自治区重点研发计划项目“广西首个页岩气示范项目地质理论与工程技术研究”(23AB06031)
广西壮族自治区国资委核心科技攻关和重大科技创新项目“广西首个页岩气区块效益化勘探开发一体化技术研究”(2060404)。
关键词
浅层页岩气
“甜点”
测井评价
地质-工程一体化
鹿寨组
桂中坳陷
shallow shale gas
"sweet spot"
logging evaluation
geology-engineering integration
Luzhai Formation
Guizhong Depression
