The Biot elastic fluid-saturated porous model is a constitutive model relationship for porous media materials proposed by Biot in the 1940s. This constitutive model couples the solid skeleton deformation with the porous media in the skeleton for analysis, and takes the time effect due to the porous media into full consideration. An introduction to the elastic porous constitutive model will be presented in Elastic Fluid-saturated Porous Media and Borehole Safety Calibration, and based on this constitutive model, the borehole damage problem in oil drilling engineering will be examined to explain the time lag phenomenon in the collapse and rupture of borehole wall.