Method for determining a derived property of a medium and nuclear magnetic measuring device, computer program product and computer-readable storage medium for such

Patent metadata

Field	Value
Publication number	US-11237236-B2
Application number	US-202017024141-A
Country	US
Kind code	B2
Filing date	Sep 17, 2020
Priority date	Sep 18, 2019
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A method includes the steps of: introducing a medium with a first temperature into a measuring volume; carrying out nuclear magnetic measurements on the medium with the first temperature; determining a property of the medium at the first temperature; determining a viscosity of the medium at the first temperature using the property; and determining a derived property of the medium at a second temperature using the property of the medium at the first temperature, the viscosity of the medium at the first temperature, the first temperature, and the second temperature. The property is at least one of a first spin-lattice relaxation time constant, a first spin-spin relaxation time constant, and a first diffusion time constant. The derived property is at least one of a second spin-lattice relaxation time constant, a second spin-spin relaxation time constant, and a second diffusion time constant.

First claim

The invention claimed is:

1. A method for the determination of at least one derived property of a medium, comprising:
introducing a medium with a first temperature (ϑ 1 ) into a measuring volume;
carrying out nuclear magnetic measurements on the medium with the first temperature (ϑ 1 ) in the measuring volume;
determining at least one property of the medium at the first temperature (ϑ 1 ) from the nuclear magnetic measurements, the at least one property being at least one of a first spin-lattice relaxation time constant (T 1 (ϑ 1 )), a first spin-spin relaxation time constant (T 2 (ϑ 1 )), and a first diffusion time constant (D(ϑ 1 ));
determining a viscosity (η(ϑ 1 )) of the medium at the first temperature (ϑ 1 ) from the at least one property; and
determining at least one derived property of the medium at a second temperature (ϑ 2 ) using the at least one property of the medium at the first temperature (ϑ 1 ), the viscosity (η(ϑ 1 )) of the medium at the first temperature, the first temperature (ϑ 1 ), and the second temperature (ϑ 2 ), the at least one derived property being at least one of a second spin-lattice relaxation time constant (T 1 (ϑ 2 )), a second spin-spin relaxation time constant (T 2 (ϑ 2 )), and a second diffusion time constant (D(ϑ 2 )).

2. The method according to claim 1 , wherein the first spin-lattice relaxation time constant (T 1 (ϑ 1 )) of the medium ( 5 ) at the first temperature (ϑ 1 ) is determined as the at least one property:
wherein the method further comprises:
determining a logarithmic average or a weighted average of the first spin-lattice relaxation time constant (T 1,LM (ϑ 1 )); and
determining the viscosity (η(ϑ 1 )) of the medium at the first temperature (ϑ 1 ) from the logarithmic average or the weighted average of the first spin-lattice relaxation time constant using the first formula
T 1,LM (ϑ 1 )≈ k 1 (η(ϑ 1 )) −k 2 +k 3 (η(ϑ 1 )) k 1 ;

wherein 0.37831≤k 1 ≤3.3887, 0.45419≤k 2 ≤1.2055, 00.88616·10 −3 ≤k 3 ≤26.547·10 −3 , and −0.023116≤k 4 ≤0.34519.

3. The method according to claim 1 , wherein the first spin-spin relaxation time constant (T 2 (ϑ 1 )) of the medium at the first temperature (ϑ 1 ) is determined as the at least one property;
wherein the method further comprises:
determining a logarithmic average or a weighted average of the first spin-spin relaxation time constant (T 2,LM (ϑ 1 )); and
determining the viscosity (η(ϑ 1 )) of the medium at the first temperature (ϑ 1 ) from the logarithmic average or the weighted average of the first spin-spin relaxation time constant using the second formula
T 2,LM (ϑ 1 )≈ k 5 (η(ϑ 1 )) −k 6 ;

wherein 0.37831≤k 5 ≤3.3887 and 0.45419≤k 6 ≤1.2055.

4. The method according to claim 1 , wherein the first diffusion time constant (D(ϑ1)) of the medium at the first temperature (ϑ1) is determined as the first property;
wherein the method further comprises determining the viscosity (η(ϑ1)) of the medium at the first temperature (ϑ1) from the diffusion time constant using the third formula
D (ϑ 1 )= k 7 η(ϑ 1 ) k 8 ;

wherein 0.2445·10 −9 ≤k 7 ≤2.2005·10 −9 and 0.375≤k 8 ≤0.650

when the first diffusion time constant (D(ϑ 1 )) of the medium at the first temperature (ϑ 1 ) is less than or equal to 3·10 −11 m 2 /s; and
wherein 0.05777·10 −9 ≤k 7 ≤0.5199·10 −9 and 0.125≤k 8 ≤0.375

when the first diffusion time constant (D(ϑ 1 )) of the medium at the first temperature (ϑ 1 ) is greater than 3·10 −11 m 2 /s.

5. The method according to claim 1 further comprising determining at least one relaxation time constant (T i (ϑ 2 ), i={1,2}) of the medium at the second temperature (ϑ 2 ) from at least one of the second spin-lattice relaxation time constant (T 1 (ϑ 2 )) and the second spin-spin relaxation time constant (T 2 (ϑ 2 )) using a temperature coefficient (dT i /dϑ) of a relaxation time constant (T i ) from at least one of the second spin-lattice relaxation time constant (T 1 (ϑ 2 )) and the second spin-spin relaxation time constant (T 2 (ϑ 2 )).

6. The method according to claim 5 , further comprising determining the at least one relaxation time constant (T i (ϑ 2 ), i={1,2}) of the medium at the second temperature (ϑ 2 ) using the fourth formula
T i (ϑ 2 )= T i (ϑ 1 ) e γϑ 2 ,

or using the Taylor polynomial of the fourth formula according to the fifth formula
T i (ϑ 2 )= T i (ϑ 1 )[1+γ(ϑ 2 −ϑ 1 )+ . . . ],

or using the approximation formula of the fourth formula, according to the sixth formula

T
i

⁡

(

ϑ
2

)

≈

T
i

⁡

(

ϑ
1

)

+

d
⁢

T
i

d
⁢

⁢
ϑ

⁢

(

ϑ
2

-

ϑ
1

)

,

which uses the seventh formula

γ
=

1

T
i

⁡

(

ϑ
1

)

⁢

dT
i

d
⁢

⁢
ϑ

7. The method according to claim 5 , further comprising determining the temperature coefficient (dT i /dϑ) using the eighth formula

dT
i

d
⁢

Assignees

• Krohne Ag

Inventors

• Tromp Rutger Reinout

Classifications

• G01R33/31

  Temperature control thereof · CPC title

• G01V3/14

  operating with electron or nuclear magnetic resonance · CPC title

• G01N24/08

  by using nuclear magnetic resonance (G01N24/12 takes precedence) · CPC title

• G01F1/716 Primary

  using electron paramagnetic resonance [EPR] or nuclear magnetic resonance [NMR] · CPC title

• G01R33/448 Primary

  Relaxometry, i.e. quantification of relaxation times or spin density (G01R33/50 takes precedence) · CPC title