The Development of Wormholes in Laboratory‐Scale Fractures: Perspectives From Three‐Dimensional Simulations

Abstract

Abstract We investigate the development of wormholes in laboratory‐scale fractures using three‐dimensional numerical simulations. Well‐controlled initial conditions, involving a small perturbation near the inlet of an otherwise flat fracture aperture field, were used to make a systematic study of the effects of flow rate and reaction rate on the aperture evolution. We find at least two characteristic wormhole shapes, which can be grouped within a phase diagram in the space of Péclet and Damköhler numbers. We investigate how this phase diagram depends on fracture geometry, specifically the length ( L ) and width ( W ) in comparison to the initial aperture ( h 0 ). This information is used to determine an effective Damköhler number that leads to a Péclet and length‐independent phase boundary between wormholes and uniform dissolution. We relate these observations to experimental studies of wormhole formation in dissolving fractures.