NMR analysis of a core sample employing an open permanent magnet removable from a core holder
First Claim
1. A method for acquiring nuclear magnetic resonance (NMR) measurements of a plurality of subterranean core samples, the method comprising:
- holding a first core sample in a first core holder under pressurized conditions, the first core holder having a first radio frequency coil disposed about a portion of the first core holder, the first radio frequency coil for generating a pulsed-mode magnetic field component over a sample volume occupied by the first core sample;
removably securing a first support structure to the first core holder, the first support structure providing resistance to forces resulting from the pressurized conditions of the first core holder, and the first support structure allowing for access to interior space surrounding the portion of the first core holder and the first radio frequency coil disposed thereabout;
removably disposing a permanent magnet into a position within the first support structure about the first radio frequency coil and the portion of the first core holder without the need for depressurization of the first core holder and detachment of the first support structure from the first core holder, the permanent magnet for applying a static magnetic field component to the sample volume occupied by the first core sample for NMR measurements of the first core sample;
holding a second core sample in a second core holder under pressurized conditions, the second core holder having a second radio frequency coil disposed about a portion of the second core holder, the second radio frequency coil for generating a pulsed-mode magnetic field component over a sample volume occupied by the second core sample;
removably securing a second support structure to the second core holder, the second support structure providing resistance to forces resulting from the pressurized conditions of the second core holder, and the second support structure allowing for access to interior space surrounding the portion of the second core holder and the second radio frequency coil disposed thereabout;
removing the permanent magnet from the position within the first support structure about the first radio frequency coil and the portion of the first core holder without the need for depressurization of the first core holder and detachment of the first support structure from the first core holder; and
after removing the permanent magnet from the position within the first support structure, removably disposing the permanent magnet into a position within the second support structure about the second radio frequency coil and the portion of the second core holder without the need for depressurization of the second core holder and detachment of the second support structure from the second core holder, the permanent magnet for applying a static magnetic field component to the sample volume occupied by the second core sample for NMR measurements of the second core sample.
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Accused Products
Abstract
An apparatus and method for NMR analysis of a plurality of core samples includes a core holder (11) that holds a core sample under pressurized conditions. A radio frequency coil (51) disposed about the core holder (11) generates a pulsed-mode magnetic field component over a sample volume occupied by the core sample. A support structure is removably secured to the respective core holder. A permanent magnet (65A, 65B) has an open configuration such that it is removably disposed into a position within the support structure about the radio frequency coil and the core holder. The open configuration allows the same permanent magnet to be used for NMR analysis of a plurality of core samples without the need for depressurizing the respective core holder and disassembling the core holder and corresponding load frame for each core sample. It also allows multiple core samples to be prepared for NMR analysis while separated from the NMR measurement apparatus.
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Citations
21 Claims
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1. A method for acquiring nuclear magnetic resonance (NMR) measurements of a plurality of subterranean core samples, the method comprising:
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holding a first core sample in a first core holder under pressurized conditions, the first core holder having a first radio frequency coil disposed about a portion of the first core holder, the first radio frequency coil for generating a pulsed-mode magnetic field component over a sample volume occupied by the first core sample; removably securing a first support structure to the first core holder, the first support structure providing resistance to forces resulting from the pressurized conditions of the first core holder, and the first support structure allowing for access to interior space surrounding the portion of the first core holder and the first radio frequency coil disposed thereabout; removably disposing a permanent magnet into a position within the first support structure about the first radio frequency coil and the portion of the first core holder without the need for depressurization of the first core holder and detachment of the first support structure from the first core holder, the permanent magnet for applying a static magnetic field component to the sample volume occupied by the first core sample for NMR measurements of the first core sample; holding a second core sample in a second core holder under pressurized conditions, the second core holder having a second radio frequency coil disposed about a portion of the second core holder, the second radio frequency coil for generating a pulsed-mode magnetic field component over a sample volume occupied by the second core sample; removably securing a second support structure to the second core holder, the second support structure providing resistance to forces resulting from the pressurized conditions of the second core holder, and the second support structure allowing for access to interior space surrounding the portion of the second core holder and the second radio frequency coil disposed thereabout; removing the permanent magnet from the position within the first support structure about the first radio frequency coil and the portion of the first core holder without the need for depressurization of the first core holder and detachment of the first support structure from the first core holder; and after removing the permanent magnet from the position within the first support structure, removably disposing the permanent magnet into a position within the second support structure about the second radio frequency coil and the portion of the second core holder without the need for depressurization of the second core holder and detachment of the second support structure from the second core holder, the permanent magnet for applying a static magnetic field component to the sample volume occupied by the second core sample for NMR measurements of the second core sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. An apparatus for acquiring nuclear magnetic resonance (NMR) measurements of a subterranean core sample, the apparatus comprising:
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a core holder for holding the core sample under pressurized conditions; a radio frequency coil disposed about a portion of the core holder, said radio frequency coil for generating a pulsed-mode magnetic field component over a sample volume occupied by the core sample; a support structure that is removably secured to the core holder, the support structure providing resistance to forces resulting from the pressurized conditions of the core holder, and the support structure allowing for access to interior space that surrounds the portion of the core holder and the radio frequency coil disposed thereabout; and a permanent magnet for applying a static magnetic field component to the sample volume, the permanent magnet having an open configuration wherein the permanent magnet is removably disposed within the support structure about the radio frequency coil and the portion of the core holder without the need for depressurization of the core holder and detachment of the support structure from the core holder. - View Dependent Claims (12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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Specification