An MR/MRI compatible core holder with the RF probe immersed in the confining fluid

Area of Science:

• Geophysics
• Materials Science
• Chemical Engineering

Background:

• High-pressure and high-temperature conditions are crucial for studying subsurface fluid behavior.
• Existing Magnetic Resonance Imaging (MRI) probes face limitations in extreme environments.
• Developing specialized probes is essential for in-situ measurements.

Purpose of the Study:

• To design and fabricate an open frame radiofrequency (RF) probe for high-pressure and high-temperature MRI.
• To test the probe's performance within a metallic core holder under demanding conditions.
• To enable the imaging of gases and supercritical fluids in porous media.

Main Methods:

• An open frame RF probe was constructed using PEEK polymer pillars.
• The probe was integrated into an MR/MRI compatible metallic core holder.
• Phase encoding MRI techniques were used for spin density mapping.
• The probe was tested for 1H and 19F resonance frequencies at 0.2 T.

Main Results:

• The probe successfully operated at pressures up to 5000 psi and temperatures of 80°C.
• The open frame design minimized background MR signals by reducing polymer material.
• Phase encoding MRI successfully mapped sulfur hexafluoride (SF6) spin density.
• SF6 was imaged both as a high-pressure gas and a supercritical fluid.

Conclusions:

• The developed open frame RF probe is suitable for high-pressure, high-temperature MRI.
• This technology facilitates the study of fluid behavior in core plugs under reservoir conditions.
• The probe design offers a simplified fabrication process and reduced background noise for enhanced imaging.