LI Kang, WANG Wei, YANG Dian-sen, et al. Application of periodic oscillation method in low permeability measurement[J]. 2020, 41(3): 1086-1094.
DOI:
LI Kang, WANG Wei, YANG Dian-sen, et al. Application of periodic oscillation method in low permeability measurement[J]. 2020, 41(3): 1086-1094.DOI: 10.16285/j.rsm.2019.0501.
Application of periodic oscillation method in low permeability measurement
Periodic oscillation method is a new method for permeability measurement of porous media. It exhibits advantages of short testing period
good stability and high precision. However
it has not been widely used for low permeability measurement in laboratory due to lack of systematic research. In this paper
the effects of different porosities and medium permeabilities on the permeability measurement results of the periodic oscillation method are numerically analyzed. In addition
the applicability of different forms of periodic waves in the permeability measurement is discussed. Conclusions from the study results can be drawn as follows. First
both the porosity and permeability can affect the process of gas pressure transfer. Second
the initial pressure equilibrium process in medium may not be needed for the periodic oscillation method as the measurement results are almost unaffected by the initial pressure distribution after a certain period of time. Third
compared with sinusoidal wave
square wave exhibits a more notable influence on the pressure response of the downstream gas. Moreover
it is observed that square wave
triangular wave and sawtooth wave are easier to be loaded in practice. Finally
based on the numerical analysis
it is suggested to use the square wave instead of sinusoidal wave in the periodic oscillation method. This study will be helpful to guide the application of the periodic oscillation method test in low permeability measurement.