A calibration method for salt rock mechanics parameters of salt-cavern gas storage

The salt-cavern gas storage has the advantages of flexible deployment, less cushion gas demand, and strong throughput, etc. However, it also has safety and stability problems, such as surface subsidence, salt rock damage, gas leakage, and cavity shrinkage. The selection and calibration of some key parameters in the stability evaluation of salt-caverns are very important. The rock mechanical parameters in the evaluation mainly include the elastic parameters and the visco-plastic parameters of the salt rocks. During the salt-cavern design stage, the selection of key mechanical parameters can only be determined by laboratory core test. Their values may have a large discrepancy with the actual parameters of the original rocks, which is common in other underground rock excavation engineering, thus the mechanical parameters of salt rocks should be further calibrated. Therefore, based on many years of experiences and data accumulation in the domestic salt-cavern gas storage cavity construction and injection-production operation, with the cavity construction and injection-production operation regression method and on-site data to calibrate creep parameters, a test method for calibrating rock mechanics parameters of salt-cavern gas storage was established. This method was applied to calibrate the elastic and visco-plastic parameters of salt rocks in Jintan salt-cavern gas storage, showing good effects of such mechanics parameters. The calibrated mechanics parameters are very important in optimizing the operating chamber injection scheme, and in improving the economy and safety of the gas storage operation. ©, 2015, Natural Gas Industry Journal Agency. All right reserved.