Balland, Cyrille and Billiotte, Joël and Tessier, Bruno and Raingeard, Anne and Hertz, Emmanuel and Hévin, Grégoire and Tribout, Daniel and Thelier, Nicolas and Hadj-Hassen, Faouzi and Charnavel, Yvan and Bigarre, Pascal (2018) Acoustic monitoring of a thermo-mechanical test simulating withdrawal in a gas storage salt cavern. International Journal of Rock Mechanics and Mining Sciences, 111. pp. 21-32. DOI: https://doi.org/10.1016/j.ijrmms.2018.07.023
Full text not available from this repository.Abstract
Natural gas storage in salt caverns requires fast injection / withdrawal cycles due to the increasing dynamics of the energy market. High rates induce rapid changes in the internal pressure of the stored gas causing important temperature changes susceptible to damage the rock salt mass. To experimentally observe this, the Starfish project aimed to characterize the damage caused by purely thermal stresses at the surface of a large bloc of rock in the salt mine of Varangéville (France). The objective was to determine the type of failure mechanism involved with repeated cooling stages. Since the salt is favourable to the generation of Acoustic Emissions (AE) and the propagation of stress waves, acoustic monitoring was chosen as one of the methods to follow the impact of the salt cooling. In addition to thermal and mechanical sensors, an acoustic monitoring device consisting of 16 ultrasonic sensors was installed on the free surface and in boreholes. It enabled to record and locate a large number of AE (58,426) located with good accuracy (2.5 cm). Those AE can be correlated to the evolution of salt fracturing. Acoustic activity is very intense at the start of each cooling cycle, then decreases with time to reach a very low level (background) after about 15 days. The average localisation depth reached by the AE is about 90 cm during the first cooling period. For subsequent cooling cycles, this depth is limited to 74 cm. These results show that the first cooling period is decisive, as it contains the strongest and deepest acoustic emissions.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | Acoustic monitoring, Underground salt mine, Gas storage, Energy, Rock mechanics, France |
| Subjects: | Methodology > Other-additional study Region > France Inducing technology > Underground storage of fluids |
| Project: | EPOS-IP > STARFISH: unconventional hydrocarbon extraction |