CO2 Sequestration
[Channeling; capillary fingering; viscous fingering; stable displacement; capillary desaturation curve; pore-scale modeling]
1. Under what circumstances, channeling is expected, which may cause a significant reduction in swept volume of the invasion fluid, when CO2 is injected into reservoirs?
Any of the following scenarios might lead to CO2 leakage in the long run?
(a) Extent of gravity difference
(b) Nature of reservoir wettability
(c) Level of geological heterogeneity
(d) Degree of instability of invasion front
2. Whether capillary fingering, which strongly circumvents the invasion-percolation from a smooth displacement front within reservoirs, could really hamper capillary trapping of CO2 (associated with the dominant capillary forces at pore-scale)?
3. How easy would it remain to maintain a stable displacement, upon injecting CO2?
What happens, when the viscosity of the invading phase remains to be lesser than that of the receding phase @ high capillary numbers?
4. Why does the behavior of Capillary Desaturation Curve (change of residual saturation with capillary number) become non-monotonic under unfavorable viscosity ratios?
Feasible to capture the dynamic fingering topology, resulting from the competition between capillary and viscous forces?
5. How easy would it remain to delineate the crossover zone between viscous fingering and capillary fingering, upon injection CO2?
For such cases, which one of the following pore-scale modelling techniques would remain to be more successful? (a) Lattice Boltzmann (b) Pore network modelling (c) Smoothed Particle Hydrodynamics (d) Volume of Fluids