Investigation on droplet dynamic snap-off process in a short, abrupt constriction

Abstract Droplet snap off is one of the most usual phenomena in oil recovery during water injection in water-wet porous media. In this work, the droplet dynamic snap-off process in a short, abrupt constriction is investigated. Three different phenomena, i.e. total breakup, partial breakup and non-breakup, of the nonwetting phase droplets are observed, the flow characteristics of droplets in each phenomenon and relevant physical mechanisms are analyzed. We find that both the initial size and velocity of the droplet greatly influence the breakup process. The viscosity of droplet also affects the breakup state. The critical conditions of each phenomenon are obtained based on dimensionless droplet size and capillary number, which could be used to predict the droplet breakup state. Under a certain capillary number, daughter droplet distribution is influenced by initial droplet size.