When mud cake is thick, formation permeability and shearwaveslowness evaluated from the attenuation of the amplitude of Stoneley wave are wrong.
当泥饼层较厚时，用斯通利波幅度衰减估算的地层渗透率及提取的横波时差是错误的结果。
2
Only when phase slowness is extracted from the Stoneley wave and the flexural wave, can the parameters of formation be obtained exactly, such as permeability and shearslowness.