Visualizing Dynamic Pore-Scale Fluid Flow in CO₂ and H₂ Storage

Common Challenges in High-Resolution Geological Imaging

Understanding subsurface fluid flow is essential to support large-scale deployment of geologic CO₂ utilization and storage (CCUS ) and underground H₂ storage. However, the complex behavior of multiphase fluids in heterogeneous porous media is not easily captured with conventional techniques.

Common challenges include:

• Limited ability to resolve capillary trapping and fluid displacement behavior at the pore scale

• Incomplete characterization of spatial heterogeneity and pore connectivity in reservoir rocks

• Difficulty observing unsteady-state flow dynamics in real time

• Uncertainty in wettability measurements and contact angle assessments at in-situ conditions

• Lack of direct visualization for trapping, saturation, and dissolution mechanisms in H₂- and CO₂-brine systems

These issues hinder reliable prediction of storage efficiency, recovery, and long-term containment.

Workflow Description

TESCAN’s dynamic micro-CT workflow for pore-scale fluid flow analysis is designed for real-time, high-resolution imaging under subsurface-like pressure and temperature conditions. The typical workflow includes:

Sample Preparation

Core plugs or mini plugs are loaded into a core holder  with fluid and gas injection capabilities.

In-situ Imaging Setup

The sample is maintained at reservoir conditions during imaging using a sealed pressure vessel.

Dynamic Real-Time Image Acquisition

Continuous 4D imaging captures fluid displacement and redistribution with no interruption between scans. 

Parameter Extraction

Data is used to derive relative permeability, contact angle distributions, and capillary number dependencies.

This approach enables researchers to study the evolution of CO₂ and H₂ distribution under controlled dynamic conditions.

Method in Focus: Micro-CT for Pore-Scale Characterization

X-ray micro-computed tomography (micro-CT) is the cornerstone of this workflow. It enables:

• High-resolution 3D visualization of porous media architecture

• In-situ multiphase imaging for tracking CO₂ or H₂ saturation over time

• Quantification of capillary trapping and fluid-rock interactions

• Measurement of pore size distributions, connectivity, and heterogeneity

Dynamic micro-CT captures displacement, drainage, and imbibition events with temporal resolution suitable for modeling unsteady-state flow and capillary effects in real reservoir materials.