Changes to coal pores by ultrasonic wave excitation of different powers
YU Guoqing
ZHAI Cheng
QIN Lei
TANG Zongqing
WU Shiliang
XU Jizhao
Abstract：Ultrasonic wave excitation has the advantage of no pollution,low energy consumption,high efficiency and energy concentration,which also has a significant influence on the fracturing results.In order to explore the influence law of power,the nuclear magnetic resonance(NMR) and detection device with ultrasonic wave velocity were used to observe the change characteristics of pore size,number and permeability in the coal under the condition of different power parameters.The experiment indicates that the micropores and mesopores will grow to be the macropores or the fracture,which attributes to the increases of macrpores,the overall porosity of coal and coal permeability,during the process of excitation.If the power is higher,the rate of P wave velocity decreasing is much greater and the nuclear magnetic resonance T2 curve peak increases obviously,at the same time,there will be greater left shift in T2 cutoff value.Under the effect of the same time,the greater the power,the more pores there will be.In addition,the low power is suitable to micropores and the influence of the high power is more obvious to change the macropores.
Keywords：ultrasoundnuclear magnetic resonance(NMR)transverse relaxation time T2poreCBM
Publication Date：2018-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 264-270,322 )