Behaviors of non-wetting phase snap-off events in two-phase flow: microscopic phenomena and macroscopic effects
- Resource Type
- Original Paper
- Authors
- Li, Ran; Gu, Zhaolin; Li, Zhang; Lu, Weizhen; Zhao, Guozhu; Su, Junwei
- Source
- Microfluidics and Nanofluidics. 28(4)
- Subject
- Snap-off
Two-phase flow
Pore network
Viscosity ratio
Residuals mobilisation
Capillary number
- Language
- English
- ISSN
- 1613-4982
1613-4990
Snap-off events are one of the most common and essential phenomena in two-phase flow in porous media. This paper uses the scanning results of a siltstone slice to construct a two-dimensional heterogeneous pore network structure to visualise microscopic snap-off phenomena and displacement processes accurately. The relationship between snap-off events and the non-wetting phase saturation was studied using two-phase flow displacement experiments. Results show that although the non-wetting phase snap-off events benefit freeing the trapped non-wetting phase in the microchannels, high-frequency snap-off events are the main reason for trapping the non-wetting phase during the displacement process, eventually leading to residuals. The frequency of non-wetting phase snap-off events in the pore network structure can be reduced to lower the non-wetting phase saturation and reduce the non-wetting phase residuals by increasing the displacement fluid viscosity, reducing the surface tension coefficient between the phases and increasing the flow rate.