Underground Hydrogen Storage
1. Whether the low-density and low-viscosity hydrogen also could be stored safely and successfully underground in depleted reservoir and saline aquifers similar to the storage of CO2?
If so, whether,
(a) the way the injected H2 displaces the in-situ reservoir fluids;
(b) the way, the H2-brine interface gets developed along with buoyant forces; and
(c) the way, the H2 gets prevented from its lateral escape – would remain to be nearly the same as that of CO2 storage;
OR
the fundamental hydrogen displacement pattern itself is going to be quite different (from that of CO2 migration) resulting from the complex interplay between capillary, viscous and gravitational forces?
2. Due to the obvious viscosity contrasts between less-viscous less-dense hydrogen and high-viscous high-dense reservoir brine, would it remain feasible to get rid-off
(a) fingering (resulting from unstable displacement during drainage) &
(b) gravity over-ride (gravity tongue)
leading to unstable displacement fronts?
3. In addition to contrasts in fluid properties, if the reservoir has geological units with differential advection (rock heterogeneity), won’t it lead to channeling (during imbibition) as well and that would eventually lead to an unrestrained lateral spreading of H2 (albeit the augmented trapping of H2 happening outside the channel)?
4. Whether the movement of H2 plume within the reservoir would follow the typical plume movement dictated by conventional advection-dispersion (hydrodynamic dispersion) equation (ADE)?
OR
Macroscopic dispersion of H2 is expected?
If not, how will we be able to deduce ‘non-uniform’ longitudinal as well as lateral movement of H2 plumes in the absence of deducing longitudinal and transverse dispersivities?
Or
If the dispersion remains to be rate-dependent?
5. How about the degree of dilution as a function of spreading length of H2 plume that gets influenced by buoyancy effect and capillary trapping?
Whether the spreading length and dilution index hydrogen mixing would get accelerated with time?
6. Even though, water wet reservoir conditions remain favorable for underground storage of hydrogen as hydrogen preferentially flows through relatively larger pores resulting in an enhanced relative permeability, won’t it also facilitate an enhanced leakage from the concerned geological unit despite it facilitates the injectivity of the reservoir?
7. Do we have sufficient experimental support for validating the contrast behavior exhibited by relative permeability curves and capillary pressure curves of hydrogen-brine system despite its exhibition of similarity with contact-angles and its associated reservoir wettability characteristics?
8. Feasible to capture relative permeability and capillary pressure curves for both drainage and imbibition of hydrogen-brine system in a porous medium @ lab-scale under transient flow conditions towards estimating residual hydrogen gas saturation?
- Badges
- Science topic
- Similar topics
- Chemistry
- Sulfites
- Inorganic Chemistry
- Inorganic Chemicals
- Salts