Dear clients,
We would like to wish you our best wishes for the New Year 2018. We greatly appreciate our relationships with all of our new friends and those with whom we have had the pleasure of working for many years. We hope that peace and success are your constant companions in the coming year.
The European Itasca team
Consulting
Itasca Consultants S.A.S. was commissioned to study the thermal-mechanical interaction between a 50 m deep, 35 m radius natural gas storage well and the surrounding ground. | ||
Zoomed view of the geometry and mesh | 
Temperature field 30 years after commissioning | |
ITASCA simulated the well construction and commissioning phases, as well as the long-term behavior of the storage. The soil constitutive law accounted for variations of its mechanical properties with temperature and for the evolution of the creep rate according to its state of the stresses, its temperature, and time. A 2D axisymmetric model was used to model this circular well. The construction phases included pre-excavation reinforcement by a freezing technique, and then a staged excavation to a depth of 50m. The steel cladding is separated from the ground by an insulating material, as well as a concrete slab. Frictional interfaces are placed between the different materials. The service phase is then modeled by simulating well filling and emptying cycles. The temperature, and the pressure applied by the gas on the steel cladding vary periodically. The simulation is carried out over a period of 30 years. The study provided estimates of:
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Axial force in the steel cladding after 30 years | 
Casing displacements 30 years after commissioning | |
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Itasca Consultants GmbH has developped numerical calculations on the time and pressure dependent behavior of backfill in mining. Backfill is used to minimize the impact of mining on the surface and to avoid sinkholes. Stiffness and strength of the backfill develop over time and depend on the confining pressure. Numerical simulations allow estimation of stress redistributions and deformations due to excavation and backfill. On this basis, the best possible time mining scheme and time for the placement the backfill can be determined. In an example calculation with FLAC3D it was shown, that in a room-pillar-mining the mining losses can be minimized with the use of residual salt as backfill material. In addition, subsidence on the surface is minimized and the risk of sinkholes is reduced.
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