  Detailed understanding of the couplings between fluid flow and solid
deformation in porous media is crucial for the development of novel
technologies relating to a wide range of geological and biological processes. A
particularly challenging phenomenon that emerges from these couplings is the
transition from fluid invasion to fracturing during multiphase flow. Previous
studies have shown that this transition is highly sensitive to fluid flow rate,
capillarity, and the structural properties of the porous medium. However, a
comprehensive characterization of the relevant fluid flow and material failure
regimes does not exist. Here, we used our newly developed Multiphase
Darcy-Brinkman-Biot framework to examine the transition from drainage to
material failure during viscously-stable multiphase flow in soft porous media
in a broad range of flow, wettability, and solid rheology conditions. We
demonstrate the existence of three distinct material failure regimes controlled
by non-dimensional numbers that quantify the balance of viscous, capillary, and
structural forces in the porous medium.
