The salt rock layer and the soft mudstone layer with salt

which have the low permeability

are usually the sealing layer of the large-scale oil-gas pool in the oil geology exploratory engineering. Thanks to the creep behavior of salt rock

the drilling technique in the salt rock layer becomes the difficult problem of drilling engineering. Based on the measured result of the drilling hole diameter between the different time

the creep rates of the rock layers in the deep stratum are obtained. The creep rate of the soft mudstone with salt is maximal. Secondly is the salt rock layer. The exponent creep constitutive law is employed to analyze the creep rate of rock layer in the three-dimensional numerical method. The creep parameters of salt rock and mudstone with salt are obtained. The parameters can be used in the optimizing analysis of the drilling mud density.