Abstract：The micro-mechanism study on desorption of coal shale gas was important for the safe and efficient exploitation that the coal shale gas in coalfield region. The non-destructive detecting technology based on nuclear magnetic resonance (hereafter referred to as a NMR) was used in experiments. Taking Qing Hemen Mine in Fuxin as the study case, the desorption process was simulated through first adsorption after constantly reduced gas pressure when the sample was placed into the low field NMR instrument. The micro-quantitative trends on the adsorption of shale-adsorbed gas and porous medium-confined gas were characterized by the nuclear magnetic resonance spectrums integrated amplitude which was equivalent to methane quantity. The mean value of the T2 relaxation time was used to quantitatively describe the shrinkage deformation of the average pore radius. From the micro-quantitative perspective, the trends of adsorbed and porous medium-confined gas were studied. Some new understandings were draw: The ranges of T2 spectrum curve for shale-adsorbed gas and free gas can be determined by the two cutoff thresholds.The relationship between adsorbed gas and gas pressure was in accordance with the Langmuir isothermal adsorption equation. The relation between porous medium-confined gas and gas pressure was linear.With the decrement of gas pressure, the average radiuses of the micro-pore structures were shrunk to 0.39 times original, the average radius of the medium-macro pore structures were shrunk to 0.25 times original.
唐巨鹏,田虎楠,马圆,孙胜杰,李卫军. 基于NMR技术煤系页岩瓦斯解吸特性试验研究[J]. 辽宁工程技术大学学报(自然科学版), 2017, 36(3): 282-287.
TANG Jupeng,TIAN Hunan,MA Yuan,SUN Shengjie,LI Weijun. Experimental study on desorption characteristics of gas in coal
shale based on NMR technology. Journal of LNTU.Natural Science, 2017, 36(3): 282-287.