Quantitative Characterization of Coal Pore and Fracture Structure Based on Low-field Nuclear Magnetic Resonance
In order to investigate the pore and fracture structure characteristics of primary and tectonic coals,the pore and fracture structure differences between primary and tectonic coals were investigated by means of low-field nuclear magnetic resonance in the Shaqu No.2 Coal Mine of Huajin Coking Coal Co.Ltd.in Lüliang,Shanxi,and the characteristics of different types of coal samples in terms of their T2 spectra,the percentage of different types of pore and fracture,the effective porosity,and the pore fractal dimension were dis-cussed.The results show that the primary coal consists of micropores,mesopores and macropores,and the micropores are dominant.Tec-tonic coal consists of micropores,small pores,mesopores and macropores,and the proportion of mesopores and macropores is much larger than that of the primary coal.In both saturated and bound water samples,the complexity and distribution of pores and fractures in tecton-ic coals are larger than those in primary coals.Comparing the differences in the gas storage and transport capacities of the two coal sam-ples,it is concluded that the tectonic coal is favorable for gas seepage,while the primary coal is more conducive to gas adsorption and diffusion.The total porosity and effective porosity of the tectonic coal are calculated to be larger than those of the primary coal,and its pore and fracture structure is more developed.In addition,the complexity of adsorption pores in tectonic coal is larger than that in prima-ry coal,while the complexity of seepage pores in tectonic coal is slightly smaller than that in primary coal.The results of this study can provide some theoretical references for the management of tectonic coal gas hazard and the efficient development of coalbed methane.
low-field nuclear magnetic resonancetectonic coalprimary coalpore structure
万方数据
维普
