Abstract
Cyclic fluid-fluid displacements in disordered media feature hysteresis, multivaluedness, and memory properties in the pressure-saturation relationship. Quantitative understanding of the underlying pore-scale mechanisms and their extrapolation across scales constitutes a major challenge. Here we find that the capillary action of a single constriction in the fluid passage contains the key features of hysteresis. This insight forms the building block for an ab initio model that provides the quantitative link between the microscopic capillary physics, spatially-extended collective events (Haines jumps) and large-scale hysteresis. The mechanisms identified here apply to a broad range of problems in hydrology, geophysics and engineering.
Highlights
Cyclic fluid-fluid displacements in disordered media feature hysteresis, multivaluedness, and memory properties in the pressure-saturation relationship
Quasistatic hysteresis is common to a variety of disparate systems, from ferromagnetic materials to shapememory alloys, which have a rugged free-energy landscape with multiple local minima separated by large energy barriers
A physical realization of this medium is an imperfect Hele–Shaw cell where localized gapthickness variations are produced by randomly placed heterogeneities or “defects”
Summary
Cyclic fluid-fluid displacements in disordered media feature hysteresis, multivaluedness, and memory properties in the pressure-saturation relationship. We find that the capillary action of a single constriction in the fluid passage contains the key features of hysteresis This insight forms the building block for an ab initio model that provides the quantitative link between the microscopic capillary physics, spatiallyextended collective events (Haines jumps) and large-scale hysteresis. Quasistatic hysteresis is the macroscale manifestation of micro-scale energy-dissipative events along this evolution It is associated with history dependence, or memory, which reflects the inaccessibility of alternative states (energy minima) due to large energy barriers[8]. Compartment models can be tailored to reproduce the hysteretic behavior of a particular system, by deriving the suitable statistical distribution of hysterons from a complete set of first-order reversal PS trajectories[8,13]. Compartment models consider all units of a given threshold to be invaded once the macroscopic forcing is exceeded, with no consideration of the spatial location of units with respect to the interface
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
