Avalanches in strong imbibition

Drainage and imbibition in porous media are two opposite fluid displacement scenarios with remarkably different underlying mechanisms. Here, the authors demonstrate that strong imbibition in porous media shows features of self-organized criticality previously observed only in drainage Slow injection of non-wetting fluids (drainage) and strongly wetting fluids (strong imbibition) into porous media are two contrasting processes in many respects: the former must be forced into the pore space, while the latter imbibe spontaneously; the former occupy pore bodies, while the latter coat crevices and corners. These two processes also produce distinctly different displacement patterns. However, both processes evolve via a series of avalanche-like invasion events punctuated by quiescent periods. Here, we show that, despite their mechanistic differences, avalanches in strong imbibition exhibit all the features of self-organized criticality previously documented for drainage, including the correlation scaling describing the space-time statistics of invasion at the pore scale.

Automated summary

The authors demonstrate that strong imbibition in porous media exhibits self-organized criticality, similar to what is observed in drainage.