A study on the effect of utilizing different constitutive models in the stability analysis of an underground gas storage within a salt structure

Abstract

Constructing caverns by the use of solution mining in salt structures creates reservoirs with large dimensions and low working costs. Additionally, the special properties of rock salt have caused salt structures recognized, for decades in industrial countries, as one of the best geo formations for storage of energy resources—including oil, natural gas, compressed air and nuclear waste. Storage of natural gas as the second most in-demand fuel gives it a special importance. In fact countries’ ability to store natural gas has played an important role in their energy managements.Predicting the behavior of gas storage reservoirs, constructed in salt structure, is extraordinarily important. By making such predictions, likely problems in operation time, such as instability and convergence, can be prevented. It can also be used to estimate maximum and minimum allowable gas pressure, one of the most important operational parameters.Until now, researchers have used different constitutive models to predict the behavior of underground gas storage. The most common among these, are the Burger analytic model, Power Law, and WIPP1 empirical models. By utilizing these three models in this research, the results show that the Power Law and WIPP models are more capable of predicting storage reservoir behavior; also that the Power Law model offers a more conservative stability analysis.