Dynamics of slow drainage in porous media

Abstract

Pressure fluctuations measured during slow drainage in a two-dimensional porous model exhibit sudden jumps that identify bursts where the invasion front proceeds abruptly. The pressure-jump size distribution is observed to be exponential. The nonscaling dynamics created fractal fronts and invaded regions described by invasion percolation. A new modified invasion percolation algorithm includes invasion dynamics. A capacitive volume associated with each interface throat results in a crossover from power-law behavior to an exponential pressure jump distribution consistent with observations.