Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10682841 | Energy | 2005 | 12 Pages |
Abstract
We have studied experimentally and numerically the displacement of a highly viscous wetting fluid by a non-wetting fluid with low viscosity in a random two-dimensional porous medium under stabilizing gravity. In situations where the magnitudes of the viscous-, capillary- and gravity forces are comparable, we observe a transition from a capillary fingering behavior to a viscous fingering behavior, when decreasing apparent gravity. In the former configuration, the vertical extension of the displacement front saturates; in the latter, thin branched fingers develop and rapidly reach breakthrough. From pressure measurements and picture analyzes, we experimentally determine the threshold for the instability, a value that we also predict using percolation theory. Percolation theory further allows us to predict that the vertical extension of the invasion fronts undergoing stable displacement scales as a power law of the generalized Bond number Boâ=BoâCa, where Bo and Ca are the Bond and capillary numbers, respectively. Our experimental findings are compared to the results of a numerical modeling that takes local viscous forces into account. Theoretical, experimental and numerical approaches appear to be consistent.
Related Topics
Physical Sciences and Engineering
Energy
Energy (General)
Authors
Grunde Løvoll, Yves Méheust, Knut Jørgen MÃ¥løy, Eyvind Aker, Jean Schmittbuhl,