摘要
利用扫描电镜和常规酸敏实验等岩矿测试手段,分析了川中某气田须家河组富含伊利石的低渗透砂岩储层的酸化效果,系统对比了酸化流动实验前后伊利石微观结构特征的变化。常规酸敏实验结果表明,盐酸酸敏程度为中等偏强,土酸酸敏程度为强。伊利石经过盐酸酸化后,晶形基本无变化。伊利石经过土酸酸化后,出现了不同程度的溶蚀:半充填孔隙的片状伊利石被溶蚀后倒塌,附着在岩石颗粒上,增大了储层孔隙体积;晶体遭受部分溶蚀,晶形模糊;酸化后产生的微粒物质附着于伊利石表面。土酸酸化破坏了岩心的原生结构。通过毛管流动孔隙结构仪测试酸化前后孔隙结构参数,表明酸化后储层有效喉道大小没有得到明显改善。
By means of lithologic instrumentations of SEM (Scanning Electron Microscope),the conventional acid-sensitivity experiments and acid effect of the low permeability sandstone reservoirs filled with goeschwitzites were analyzed in Xujiahe Formation,cer-tain gasfield,Central Sichuan.The variation of microcosmic structural feature of the goeschwitzites before and after acid flow-ing experiments was compared systematically.Normal experiments show that the acid-sensitivity of HC1 is moderate or strong,and mud acid is strong.Crystal forms of the goeschwitzites have little change after HC1 acidulation;but have various degree corrosion after mud-acid acidulation,which mainly divided into three conformations.The first,the flaky goeschwitzites with half filled pore collapsed after corrosion,clinged on the rock particles,and swelled reservoir pore volumes;the second,crystal bodies suffered partial corrosion,and the crystal forms were vagueithe third,the particulate matters after acidation ad-hered to the surface of goeschwitzites.Original texture of the cores was destroyed after mud acid acidulation.Through testing the parameters of pore structures by Capillary Flow Porometer(PMI).the effective throat size of the reservoir is not improved obviously after acidation.
出处
《油气地质与采收率》
CAS
CSCD
北大核心
2010年第1期105-107,共3页
Petroleum Geology and Recovery Efficiency
基金
中国石油天然气集团公司中青年科技创新基金项目(06E1019)
四川省教育厅青年基金项目(2006B061)
关键词
低渗透砂岩
酸化
伊利石
微观结构
孔隙结构
low permeability sandstone
acidulation
goeschwitzites
rriicrocosmic structurejpore structure
