When the pore is small, the physics change. Condensation, a phenomenon when vapor chills into liquid, typically happens when vapor pressure is greater than saturation pressure. When pores are small, however, condensation can happen when vapor pressure is smaller than saturation pressure, according to Kelvin Equation.
The implications are significant — if you keep squeezing a dry sponge, you will squeeze water out of it! In theory.
Well, it is not significant in this way. Practically, it is almost impossible to squeeze water out of a dry sponge with your bare hands.
This property, however, is very important in many industrial applications, such as in Atomic Force Microscopy, material sintering, and Microelectromechanical systems (MEMS).
DigiM developed numerical models to correlate capillary condensation with the storage capability of a porous material. Using this model, we helped our client to successfully revise the gas-in-place (GIP) estimate of Duverney gas shale, and explained the discrepancy between field observation and original GIP model.