为研究岩石的孔隙结构特征,采用核磁共振技术(NMR)对花岗岩进行测量,得到花岗岩的横向弛豫时间t2分布、NMR测量结果和核磁共振成像图像。研究结果表明:花岗岩的t2分布主要为3个峰,第1个峰和第2个峰的面积占峰总面积的98%以上;岩石组成颗粒粒度的不同,引起了岩石核磁共振弛豫特性的差异。花岗岩的平均孔隙度为1.79%,tr2平均值为26.1ms,束缚流体饱和度平均值占88.5%,核磁共振成像显示岩石的孔隙结构特征,为孔隙结构分析提供依据。岩石核磁共振特征的变化规律和成像结果为岩石微观结构和岩石损伤机理研究提供实验数据。
For knowing the rock pore structure, the crosswise relaxation time t2 distribution, nuclear magnetic resonance (NMR) measurement results and magnetic resonance imaging (MRI) were obtained by measuring granite with NMR technology. The results have shown that t2 distribution of granite exhibits three peaks and the subtotal spectrum area of the first one and the second occupied more than 98% of the total area. The different components of particle size in the rock have leaded to the variation of NMR relaxation properties. The average porosity of granite is 1.79%, t'2 is 26.1 ms and average irreducible saturation is 88.5%. The structural characteristics of the rock visually shown by the MRI, have provided the information for analysis of the rock pore structure. The variation law of NMR characteristic in rock and its MRI results have provided experimental database for research of the rock microstructure and rock deterioration mechanism.