Apparatus and methods for determining properties of hydrogen-containing samples using nuclear magnetic resonance
AssigneeSchlumberger Technology Corporation
InventorsRavinath Kausik Kadayam Viswanathan, Yiqiao Song
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Abstract
Nuclear magnetic resonance (NMR) methods and apparatus are provided for investigating a sample utilizing NMR pulse sequences. In various embodiments, the NMR pulse sequences have a solid state portion and a line-narrowing portion. In other embodiments, the NMR pulse sequences have a first line-narrowing portion and a second line-narrowing portion where the sequences of the different portions are different. In yet other embodiments, the NMR pulse sequences have a T1 portion and a line-narrowing portion. Processing of detected signals permits determination of characteristics of the sample including, in some cases, a differentiation of multiple components of the sample.
Claims20
A nuclear magnetic resonance (NMR) tool for investigating a sample having a solid portion and a fluid portion, comprising:
- a magnet;
- a transmitter, including a pulse sequencer and a power amplifier, which is configured to generate and transmit an NMR pulse sequence including a first portion and a line-narrowing pulse sequence portion, wherein the first portion comprises a solid state pulse sequence of a first type, and wherein the line-narrowing pulse sequence portion comprises a repeated solid state pulse sequence of a second type different than said first type;
- a receiver including at least one antenna arranged to detect signals resulting from interaction of an NMR field varying according to the NMR pulse sequence with the sample, said signals including at least one echo that results from said first portion and a plurality of echoes between pulses of said line-narrowing pulse sequence portion, wherein said at least one echo that results from said first portion is indicative of total hydrogen content of the sample in both the solid portion and the fluid portion of the sample, and wherein said plurality of echoes is indicative of hydrogen content in the fluid portion of the sample;
- and
- a processor that processes said at least one echo that results from said first portion and said plurality of echoes to determine hydrogen content in the solid portion of the sample.
A nuclear magnetic resonance (NMR) tool for investigating a sample, comprising:
- a magnet;
- a transmitter, including a pulse sequencer and a power amplifier, which is configured to generate and transmit an NMR pulse sequence including a T1 pulse sequence portion and a line-narrowing pulse sequence portion, wherein said line-narrowing pulse sequence portion comprises a repeated solid state pulse sequence;
- a receiver including at least one antenna arranged to detect signals resulting from interaction of an NMR field varying according to the NMR pulse sequence with the sample, said signals including a plurality of echoes between pulses of said line-narrowing pulse sequence portion;
- a processor that processes said signals detected by the receiver using a combination of an inverse Laplace transform and a Fourier transform and generates a T1-chemical shift map that distinguishes a plurality of species of hydrogen content of the sample from each other.
A method of investigating a sample having a solid portion with a solid hydrogen content and a fluid portion with a fluid hydrogen content, comprising:
- generating and subjecting the sample to an NMR field, said NMR field varying according to an NMR pulse sequence including a first portion and a line-narrowing pulse sequence portion, wherein the first portion comprises a solid state pulse sequence of a first type, and wherein the line-narrowing pulse sequence portion comprises a repeated solid state pulse sequence of a second type different than said first type;
- detecting signals resulting from interaction of said NMR field with the sample, said signals including at least one echo that results from said first portion and a plurality of echoes between pulses of said line-narrowing pulse sequence portion, wherein said at least one echo that results from said first portion is indicative of total hydrogen content of the sample including both the solid hydrogen content and the fluid hydrogen content in the sample, and wherein said plurality of echoes is indicative of the fluid hydrogen content in the sample;
- processing said at least one echo that results from said first portion and said plurality of echoes to determine the solid hydrogen content of the sample.
A method of investigating a sample having hydrogen content, comprising:
- generating and subjecting the sample to an NMR field, said NMR field varying according to an NMR pulse sequence including a T1 pulse sequence portion and a line-narrowing pulse sequence portion, wherein said line-narrowing pulse sequence portion utilizes a repeated solid state pulse sequence;
- detecting signals resulting from interaction of said NMR field with the sample, said signals including a plurality of echoes between pulses of said line-narrowing pulse sequence portion;
- processing said detected signals using a combination of an inverse Laplace transform and a Fourier transform and generating a T1-chemical shift map that distinguishes a plurality of species of hydrogen content of the sample from each other.
Dependencies are inferred from the claim text.