核磁共振方法在苏里格致密砂岩储层孔隙结构中的应用

Application of NMR Method to the Pore Structure Study of Tight Sandstone Reservoir of Sulige Gasfield

利用低场核磁共振实验的方法和压汞数据研究了鄂尔多斯盆地苏里格气田上古生界盒8段岩心样品．找出了核磁共振孔分布与由压汞毛管压力曲线所获得的孔喉半径分布之间的对应关系和转换方法，建立了T2几何平均值与毛管压力曲线孔喉结构参数之间的统计关系。结果表明，苏里格致密砂岩储层的核磁共振乃分布与由毛管压力曲线所获得的孔径分布之间存在密切的相关性，二者都反映了岩石的孔隙结构，利用核磁共振技术来评价致密砂岩储层的孔喉结构是有效的，同时也为利用核磁共振测井技术开展致密砂岩储层评价提供了实验基础。

The transformation method and correlation or matchup between NMR-derived T2 distribution and pore-lhroat radius distribution obtained from capillat7 pressure curve by mereury intrusion method have been found out through utilizing low-field nuclear magnetic resouance （NMR） experiment and data fi＇om mercury intrusion methods to research the core samples from Upper Palaeozoic He8 Member of Sulige gasfieht of Ordos basin. The statistical relation between T2 geometric mean and pore-throat structure parameters from capillary pressure curve is established. The results indicate that close correlation exists between the NMR-derived T2 distribution of tight sandstone reservoirs of Sulige gasfield and pore-throat radius distribution obtained from capillary, pressure out＇re by mercury intrusion method. Both of them reflected pore structure of rock. It is effective to evaluate the pore-throat structure of tight sandstone reservoirs by using nuclear magnetic resonance technique, which also provides an experiment foundation for tight sandstone reservoir evaluation by utilizing NMR logging technique.