Hysteresis behavior in dissociating hydrate-bearing sediments
| Main Author: | min Li |
|---|---|
| Format: | Article |
| Terbitan: |
, 2021
|
| Online Access: |
https://zenodo.org/record/5169801 |
Daftar Isi:
- Hysteresis behavior is a key factor in exploring the dynamic water and gas flow in dissociating hydrate-bearing sediments (HBS). In this study, we combined microfocus X-ray computed tomography (CT) and a pore network model (PNM) to analyze the effect of gas trapping on the hysteresis in capillary pressure Pc and relative permeability kr in water-wet and gas-wet systems. The simulated results confirmed that the residual gas saturation Sgr in the water-wet system was significantly higher than that in the gas-wet system because of the snap-off. Secondary hydrate formation promotes gas trapping. The gas trapping has a huge impact on the hysteresis in Pc and kr between the drying and wetting cycles in HBS. Therefore, it is crucial to explore gas trapping in the Pc and kr models to accurately predict the distribution and mobility of water and gas in HBS. Finally, we also propose the use of dynamic scanning flow for analyzing complex water and gas displacement sequences in dissociating HBS.