Through analyzing mineral composition of the rock salt and rock gypsum-salt in Chuandong gas field

the creeping test study is carried out with the TAW-1000 deep pore pressure servo test system. The impacts of mineral compassion

deviator stress

temperature and confining pressure on creep have been analyzed. Based on the creep curve and rock parameters obtained by the experiment，steady-state creep rate constitutive equation is proposed. The results show that the main mineral compassion of rock salt and rock gypsum-salt in Chuandong gas filed are sodium chloride and calcium sulfate; the highest percentage of sodium chloride can be as much as 93%

inherent mineral composition is the internal factors of rock creep. The higher sodium chloride content is

the larger transient creep and steady-state creep rate become; the higher deviator stress and temperature are

the larger steady-state creep rate will be

on which the effect of confining pressure is very small. The parameters of Heard creep constitutive equation are obtained by fitting test data; and then the steady-state creep rates of rock salt and rock gypsum-salt under different deviator stresses and temperatures can be acquired. Eventually

it can provide theoretical basis for safe drilling of rock salt and rock gypsum-salt for Chuandong gas field

mud density calculation and abnormal casing deformation.