Thermal cracking following a blowout in a gas-storage cavern

In this paper, the nucleation and the propagation of thermal cracks following a severe thermal shock in gas storage caverns leached out from a salt formation are studied. This shock is induced by a quick release of the gas stored in the cavern following a rapid gas withdrawal from the cavern. A first model takes into account pressure and temperature changes at the cavern wall to reach critical stress. It also justifies a rate-independent hypothesis in salt formations for rapid loadings. The second model used is the one developed in the variational approach to fracture, which can predict nucleation of cracks as well as their propagation in a single framework, with no a priori hypothesis on the topology of the cracks. We illustrate that cracks nucleate on the rock wall with periodic spacing. The geometry of the cavern has little influence. Furthermore, as the heat diffuses, cracks penetrate and their spacing, ruled by Griffith׳s law, follows a characteristic scale law.