Effects of Ratcheting Strain on Cyclic Time-Dependent Parameters of Salt Rocks
Farhang Sereshki1, Amir Saffari2
Citation : Farhang Sereshki, Amir Saffari, Effects of Ratcheting Strain on Cyclic Time-Dependent Parameters of Salt Rocks International Journal of Mining Science 2016, 2(1) : 15-24
Salt rock is a particular medium for underground storage of natural gas. From the view point of operation of salt caverns, a seasonal storage pattern has been applied so far. However, more frequent cycling of internal pressure in terms of mass flow and pressure gradients is required today. The objective of the current study is to find the relationship between ratcheting strain pattern and cavern closure during their operational life. For this purpose, an experimental investigation is used to assess the effect of ratcheting pattern on timedependent properties of the host rock. The results reveal that viscoelastic and viscoplastic parameters of the rock salt exponentially decrease by increasing the loading frequency and deviatoric stress amplitude. Also, viscoplastic coefficients are much more sensitive to the frequency of pressure fluctuations.