Discussion of “a multifractal geometric model for estimating spontaneous imbibition in an unsaturated fractured core-scale network in a low-permeability reservoir”

Abstract

In December 2024, this journal published the paper “A multifractal geometric model for estimating spontaneous imbibition in an unsaturated fractured core-scale network in a low-permeability reservoir”. The paper develops imbibition models for a single fracture and for multiple fractures, and validates these with measurements from literature: partial success of the models is claimed ensuingly. This post-publication critique however articulates serious concerns on both fracture imbibition models. For both, it is verified that the model validation is mostly void, owing to a multitude of flaws in the model configuration and/or parameter input. Concretely, this critique shows that the fractal tortuosity approach results in physically implausible tortuosities, that the (fractal) roughness correction is incorrectly employed, that adopting the measured time coefficient brings about a strong non-robustness. Additionally, it is established that there are strong deviations between the modelled and measured configurations. The critique invites the authors of the discussed paper to appease these concerns in their reply, to reconfirm the reliability of their work.