When mud cake is thick, formation permeability and shear wave slowness 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
The disadvantage of API filtration test to evaluate mud cake quality is analyzed. A method, taking mud cake strength, permeability and thickness as main evaluation factors is introduced.
On the contrary, size distribution and fractal dimension of particulate matters in backwash water were more important in determining specific cake resistance and permeability.