Zirconia Ceramic Core Sample Holder for High Pressure NMR
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Solution Overview
Problem
Current core sample holders for NMR and MRI analysis are limited by their inability to withstand high pressures and temperatures, and they often have issues with radial pressure distribution and sealing, which restricts their operational pressure and temperature capabilities.
Innovation Solution
A core sample holder made from zirconia ceramic with a modified square thread design that minimizes radial pressure on the housing, allowing for higher pressure and temperature resistance, and includes sealing mechanisms like o-rings to maintain a high-pressure seal, enabling the application of axial and radial forces to simulate underground conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a thin-walled housing is used to fit within NMR/MRI bore diameter limits, then the device can be used with standard NMR spectrometers, but the housing cannot withstand high internal pressures
Solution Approach 1:
The housing is made from zirconia ceramic, a composite material that provides both the mechanical strength needed to withstand high pressures (up to 35,000 psi) and the non-magnetic properties required for NMR/MRI compatibility. This material selection resolves the contradiction by achieving both adaptability to standard spectrometers and sufficient pressure resistance.
2Ease of operation
If standard thread designs are used to fasten end plugs, then assembly is simplified, but radial pressure on the housing increases reducing maximum operating pressure
Solution Approach 1:
The thread design is optimized locally at the threaded portions of the housing to minimize radial pressure. The modified square thread profile with a thread angle of less than 14 degrees creates a load-bearing face that directs forces more axially, reducing radial stress on the housing wall while maintaining ease of assembly and disassembly.
3Object-affected harmful factors
If fiberglass or composite plastic housing materials are used, then non-magnetic requirements are met, but pressure and temperature capabilities are insufficient for geological research
Solution Approach 1:
Zirconia ceramic is selected as the housing material because it maintains the non-magnetic property required for NMR/MRI applications while providing superior temperature resistance (capable of withstanding temperatures over 300°C) and pressure resistance compared to fiberglass or composite plastic materials.
4Reliability
If end plugs are fastened with radial pins through the housing wall, then alignment issues are avoided, but assembly and disassembly become difficult
Solution Approach 1:
The fastening mechanism uses threaded portions with a modified square thread profile instead of radial pins. This parameter change in the connection geometry maintains reliable fastening and sealing while enabling easier assembly and disassembly through rotational motion, avoiding the alignment and tooling requirements of pin-based systems.
Data Source
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AI summary
The present invention relates to a sample holder that can withstand high pressures and temperatures. In one embodiment, the sample holder of the present invention can be used to subject a geological sample to the same temperature and pressure that the sample would experience in its native underground environment. The present invention provides a mechanism for hydrostatically confining the rock core sample to simulate the below ground pressure, while simultaneously allowing fluid to be directed through the core, as needed. In various embodiments, the material used for the housing of the sample holder, specifically ceramic zirconia, and the mechanism by which the end fixtures are mounted in the housing, e.g., a square thread or modified square thread, allow for operation at higher pressures and temperatures than is offered by currently available systems. In one embodiment, the device of the present invention can be used to analyze rock core samples via NMR spectroscopy or MRI.