Field permeability energy storage field

What is relative permeability?

Relative permeability is one of the key flow functions that describe how easily hydrogen can flow through porous media in the presence of other fluids. In underground storage, hydrogen is cyclically injected and withdrawn multiple times, and its relative permeability may differ between these two processes, described as hysteresis.

Why is permeability important?

Permeability is the property of a porous material that determines how easily fluid flows through that material—a basic measure of the producibility and injectivity of subsurface formations. Without sufficient formation permeability, oil and gas production, secondary and tertiary recovery, and carbon sequestration are impossible.

How is permeability measured?

In the field, permeability can be estimated in the near-wellbore region using well log data, primarily from nuclear magnetic resonance (NMR) tools. Permeability on the reservoir scale is typically determined with downhole reservoir tests and pressure transient analyses.

How does hydrogen relative permeability differ in underground storage?

In underground storage, hydrogen is cyclically injected and withdrawn multiple times, and its relative permeability may differ between these two processes, described as hysteresis. In this paper, we investigate hydrogen relative permeability in the laboratory and match with results from numerical simulations.

What is a common unit for permeability?

The common unit for permeability is the darcy, named for French engineer Henry Darcy. His experiments with water and sand led to the formulation of Darcy’s law, which describes the steady-state flow of fluid through porous media. Although permeability is nearly directly proportional to the material’s porosity, many factors affect permeability.

Does air permeability affect a stable flow state?

Despite the faster response of the air medium to permeability changes, it was difficult to instantly achieve a stable flow state. Fig. 14.