Grain-Scale Model of Coupled Multiphase Fluid Flow and Sediment Mechanics
We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on grains due to pore fluid pressures, and surface tension between fluids. This mo...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2009
|
| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.192.7164 http://www.netl.doe.gov/technologies/oil-gas/publications/Hydrates/2009Reports/Thesis_AntoneJain.pdf |
| Summary: | We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on grains due to pore fluid pressures, and surface tension between fluids. This model, which couples multiphase fluid flow with sediment mechanics, permits investigating the upward migration of gas through a brine-filled sediment column. We elucidate the ways in which gas migration may take place: (1) by capillary invasion in a rigid-like medium; and (2) by initiation and propagation of a fracture. We find that grain size is the main factor controlling the mode of gas transport in the sediment, and show that coarse-grain sediments favor capillary invasion, whereas fracturing dominates in fine-grain media. The results have important implications for understanding vent sites and pockmarks in the ocean floor, deep sub-seabed storage of carbon dioxide, and gas hydrate accumulations in ocean sediments and permafrost regions. Our results predict that, in fine sediments, hydrate |
|---|