Abstract: This study aims at investigating the deformation behavior of rock salt as reservoir medium under long-term operation. Uniaxial creep experiments were conducted on rock salt specimens for 359 days, and the law of real-time acoustic emission (AE) signal was also monitored during the test. The results show that three stages of AE were identified in the uniaxial creep experiment. The cumulative AE event location indicates that the distribution of AE signals at each stage corresponds to the positions of deformation and failure of the specimen. Meanwhile, the relationship between accumulative AE event and the creep strain was approximately linear, which proves that the number of AE events can be used to establish the creep constitutive model of rock salt. Hence, a constitutive model of rock salt damage evolution was developed based on AE data. In addition, parameters in the constitutive model were determined by fitting experimental data with the least squares method. Fitting curves show that the proposed creep constitutive model can well describe three creep characteristic stages of rock salt .

Key words: creep, acoustic emission, damage, fractional differential, uniaxial compression