测井技术2017，Vol.41Issue(5)：512-516,5.DOI:10.16489/j.issn.1004-1338.2017.05.003
基于核磁共振的页岩粉碎样品孔隙度研究
Porosity Measurement of Crushed Shales Using NMR
摘要
Abstract
Researchers prefer to use crushed shales rather than plugs to derive the total porosity.However,there is no generally acceptable conclusion for the crushing level.Based on this,the different-frequency with low-field NMR apparatuses is used to measure the shale samples with different crushing sizes.Our aim is to evaluate the validity of shale porosity using NMR and the relationship between particle size and shale porosity.The higher frequency NMR instruments (23 MHz) have obvious advantages in signal-to-noise ratio and echo interval contrast to the 2 MHz apparatus,which makes it better in porosity measurement.The NMR (23 MHz) porosity for the aliquot within the range of 60 meshes consistent with the intact aliquot.As the particle is crushed to 120 meshes,the pore structure of the two samples will be destroyed and the porosity will also reduce to a certain extent.While crushing over 230 meshes,the main grain composition of silt will be altered,as a result,T2 spectrum of all samples will be changed,and the porosity decreases obviously.It indicates that crushing within a certain range can still maintain the integrity of the pores.However,once excess a certain mesh,the shale particle size composition and pore structure will be destroyed,resulting in a significant reduction in the porosity.The comparative analysis between the shale crushing degree and grain size shows that cuttings within 60 meshes can still accurately characterize the porosity of shale reservoir well.关键词
岩石物理实验/核磁共振/页岩/孔隙度/页岩碎样/颗粒尺寸Key words
petrophysical experiment/NMR/shale/porosity/crushed shale/particle size分类
天文与地球科学引用本文复制引用
孙建孟,宗成林,董旭,刘海山,张哲夫..基于核磁共振的页岩粉碎样品孔隙度研究[J].测井技术,2017,41(5):512-516,5.基金项目
国家自然科学基金(41574122、41374124) （41574122、41374124）
国家科技重大专项(2016ZX05006002-004) （2016ZX05006002-004）
