Abstract: To study the influence of different liquid nitrogen and water cooling temperatures on the physical properties of the white sandstone, the low-field nuclear magnetic resonance imaging (MRI) method was used to measure the T2 spectrum of the white sandstone. The water and liquid nitrogen were used to cool the rock mass at different temperature stages (200℃~600℃). The influence of temperature, water-cooling and liquid nitrogen-cooling on the physical properties of the white sandstone is analyzed from the microscopic point of view, namely the change of rock pores. The test results show that: the 500℃ can be used as a critical value of different cooling methods on the changes in the intrinsic properties of the rock mass, above 500℃, the internal porosity of the rock mass changes significantly. The results show that the change of rock mass after the liquid nitrogen cooling is greater than the effect of the water cooling.

Key words: Nuclear Magnetic Resonance Imaging (MRI), Porosity, Water, Liquid Nitrogen