Permeability and Sealing Mechanisms in Porous Geological Media

Permeability and sealing in porous geological media govern the movement and retention of fluids in the subsurface, with critical implications for hydrocarbon recovery, groundwater management, carbon capture and storage (CCS), and underground gas or waste repositories. Permeability arises from interconnected pore networks that allow fluid flow, while sealing capacity depends on pore throat geometry, mineralogy and mechanical integrity to prevent unwanted migration. Natural media exhibit hierarchical heterogeneity, from nanometre-scale clay interlayers to metre-scale fracture corridors. Diagenetic alterations, compaction and overpressure further modify pore structures and anisotropy, influencing capillary entry pressures and breakthrough thresholds. Effective seals exploit capillary forces, low permeabilities and favourable mechanical properties to maintain pressure differentials, whereas compromised seals can lead to leakage pathways via fracturing or matrix dilation. Contemporary research integrates laboratory methods, numerical modelling and field-scale trends to quantify key parameters such as capillary pressure curves, threshold breakthrough pressures and compaction-porosity relationships. A unified understanding of these mechanisms is essential for safe CO2 containment, sustainable resource extraction and long-term stability of subsurface storage sites worldwide.

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Permeability and Sealing Mechanisms in Porous Geological Media publication trend

The graph below shows the total number of articles in permeability and sealing mechanisms in porous geological media across all publications each year (not limited to Nature Index journals).

Technical terms

Porosity: Fraction of a rock’s volume occupied by void spaces, controlling fluid storage.

Permeability: Measure of a porous medium’s ability to transmit fluids under a pressure gradient.

Capillary pressure: Pressure difference across a fluid–fluid interface within pore throats, governing entry or retention of a non-wetting phase.

Breakthrough pressure: Minimum pressure required for a fluid to invade and pass through a sealing layer.

Caprock: Low-permeability geological layer that acts as a seal to prevent upward fluid migration.

Mudstone: Fine-grained sedimentary rock with clay-dominated matrix often serving as a top-seal in subsurface storage.

References

1. Threshold capillary pressure of caprocks for CO2 storage: Numerical insight on the dynamic and residual method. International Journal of Greenhouse Gas Control (2024).
2. Porosity in mudstones and its effectiveness for sealing carbon capture and storage sites. Geological Society London Special Publications (2023).
3. Regional mudstone compaction trends in the Vienna Basin: top seal assessment and implications for uplift history. International Journal of Earth Sciences (2023).