Rock porosity quantification by dual-energy X-ray computed microtomography

Area of Science:

• Materials Science
• Physics
• Geology

Background:

• X-ray microtomography is crucial for analyzing porous media, but struggles with sub-micron pore detection.
• Limited spatial resolution and noise in microfocus X-ray sources hinder the accurate characterization of microporosity.

Purpose of the Study:

• To develop and validate a dual-energy methodology for improved microporosity imaging.
• To enhance the quantitative analysis of porosity in materials using X-ray microtomography.

Main Methods:

• A dual-energy scanning approach using two different voltages (80kV and 130kV) on a microfocus bench-top microtomography system.
• Generation of density-based images from dual-energy scans, quantized to represent material density.
• Comparison of porosity measurements from dual-energy, single-energy, and helium injection methods.

Main Results:

• Dual-energy imaging significantly improved the detection and quantification of microporosity compared to single-energy microtomography.
• Density images derived from dual-energy scans showed better agreement with helium injection porosity measurements.
• Acquired dual-energy images demonstrated high correlation with the actual density values of the sample.

Conclusions:

• Dual-energy X-ray microtomography is a superior method for accurate porosity evaluation, especially for materials with significant microporosity.
• This technique overcomes the limitations of single-energy microtomography, providing more reliable data for porous media characterization.