Geomechanical Simulation to model creep deformation of salt formation

To combat the increasing demand of renewable energy, development of effectual system for energy storage is needed. Salt caverns serve as the feasible and efficient solution for hydrogen storage. Studying the complex structure and analysing deformation behaviour of these formations requires clear geological domain knowledge, suitable numerical technique and proper computational model when going to predict long-term deformation and associated stress state. In this work, a 2D finite element simulator code has been utilized to probe deformation characteristics of salt formation. Two cases: (i) creep under monotonic loading, and (ii) creep under cyclic loading are deployed to investigate the influence of non-linear primary creep and change in stress magnitudes under in situ conditions. Damage and creep constitutive laws like generalized Hooke's Law, total potential energy principle, infinitesimal deformation theory etc are utilized in the simulation engine assuming constant strain triangle elements. At suitable boundary conditions, the model captured axial deformation under uniaxial compression condition of the studied salt formation with the experimental data. A good match of compressive axial deformation is observed between experimental and numerical results. Finally, the model will be extended to understand permeability evolution under monotonic loading and possible relationship with volumetric change from gas transmission permeability measurement.