Explanation of early failure in porous media confined with flexible layers, considering thermo-osmosis, thermal-filtration and heat sink from fluid dilation

Coupled thermo-hydraulic-mechanical behavior of low permeable porous media is crucial to sustainability and efficiency of multiple operations such as thermal fracturing, geothermal, and radioactive-waste disposal. This work presents fully-coupled thermo-poroelastic solutions for transversely isotropic medium, incorporating three novel components: (a) thermo-osmosis, thermal-filtration, and heat sink due to fluid dilation; (b) transient heat transfer between source/sink and the target layer; and (c) vertical confinement governed by seal rock stiffness. The first component (a) is found to be most substantial subsequent to source/sink implementation, generating considerable pore pressures that dissipate over time. The ratio of fluid bulk module (Kf) to that of the solid phase (Ks) governs the importance of the aforementioned short-term thermal effects (inconsequential heat sink due to fluid dilation for Kf/Ks