Study on the Effect of Particle Size on NMR Pore Characterization of Cuttings

To study the effect of particle size on nuclear magnetic resonance (NMR) pore characterization of sandstone, core samples were gradually crushed into five particle sizes and the transverse relaxation time (T2) spectrum and NMR response characteristics of the crushed samples were measured. The experimental results show that within the particle size range of 2.4 mm, the T2 spectrum position, T2 mean value, and NMR porosity of sandstone cuttings are basically consistent with the core samples. When the particle size is 1.2 mm, the right peak amplitude of the T2 spectrum increases significantly, and the T2 mean value representing the T2 spectrum characteristics becomes larger, which is presumed to be related to the increase in particle surface water. A comparative analysis suggests that cuttings with particle sizes larger than 2.4 mm can accurately characterize the NMR response characteristics of core samples.