US4728892A
Expired / Lapsed
US
⏱️ 0.0 years remaining
NMR imaging of materials
Assignee: Shell USA Inc
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Filing: 1985-08-13
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Granted: 1988-03-01
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Expires: 2005-08-13
Abstract
Abstract NMR imaging methods are provided for determining the spatial petrophysical properties of materials. These methods employ the generation of separate M o , T 1 and T 2 images from which various petrophysical characteristics may be obtained, such as free fluid index, porosity, pore sizes and distributions, capillary pressure, permeability, formation factor and clay content.
Inventors
- 👤 Harold J. Vinegar
- 👤 William P. Rothwell
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 03:35
CPC Classifications
G; G01; G01V; G01V3/00; G01V3/18; G01V3/32; G01R; G01R33/00; G01R33/20; G01R33/44; G01R33/48; G01R33/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
68 words
A method for obtaining at least one petrophysical property of a porous material containing therein at least one preselected fluid, comprising: NMR imaging said material to generate signals dependent upon both M(0) and T 1 and M(0) and T 2 , generating separate M(0), T 1 and T 2 images from said signals, and determining said at least one petrophysical property from at least one of said images.
Claim 2
Independent Claim
68 words
A method for obtaining at least one petrophysical property of a porous material containing therein at least one preselected fluid, comprising: NMR imaging said material to generate signals dependent upon both M(0) and T 1 and M(0) and T 2 , generating separate M(0), T 1 and T 2 images from said signals, and determining said at least one petrophysical property from at least one of said images.
Claim 3
Dependent Claim
90 words
The method of claim 1, wherein said at least one petrophysical property comprises pore sizes and their distribution, and further comprising, decomposing said T 1 , T 2 , or both of said T 1 and T 2 signals into a plurality of respective T 1 , T 2 , or both T 1 and T 2 , values and corresponding weighting coefficients, and determining pore sizes and distributions from said plurality of T 1 , T 2 , or both T 1 and T 2 values and weighting coefficients.
Claim 4
Dependent Claim
97 words
The method of claim 1, wherein said at least one petrophysical property comprises capillary pressure, and further comprising, decomposing said T 1 , T 2 , or both of said T 1 and T 2 signals into a plurality of respective T 1 , T 2 , or both T 1 and T 2 values and corresponding weighting coefficients, determining pore sizes and distributions from said plurality of T 1 , T 2 , or both T 1 and T 2 values and weighting coefficients, and determining said capillary pressure from said determined pore sizes and distributions.
Claim 5
Dependent Claim
101 words
The method of claim 1, wherein said at least one petrophysical property comprises permeability, and further comprising, decomposing said T 1 , T 2 , or both of said T 1 and T 2 signals into a plurality of respective T 1 , T 2 , or both T 1 and T 2 values and corresponding weighting coefficients, determining pore sizes and distributions from said plurality of T 1 , T 2 , or both T 1 and T 2 values and weighting coefficients, determining capillary pressure from said determined pore sizes and distributions, and determining permeability from said capillary pressure.
Claim 6
Dependent Claim
104 words
The method of claim 1, wherein said at least one petrophysical property comprises clay content, and further comprising, decomposing said T 1 , T 2 , or both of said T 1 and T 2 signals into a plurality of respective T 1 , T 2 , or both T 1 and T 2 values and corresponding weighting coefficients, determining pore sizes and distributions from said plurality of T 1 , T 2 , or both T 1 and T 2 values and weighting coefficients, and determining said clay content from said determined pore sizes and distributions and said values of T 2 .
Claim 7
Dependent Claim
32 words
The method of claim 1, wherein said at least one petrophysical property comprises free fluid index, and further comprising, determining said free fluid index from at least one of said M(0) images.
Claim 8
Dependent Claim
50 words
The method of claim 1, wherein said at least one petrophysical property comprises porosity, and further comprising, determining an M(0) image of a calibration sample containing said at least one preselected fluid, and determining said porosity from at least one of said M(0) images and said calibration sample M(0) image.
Claim 9
Dependent Claim
31 words
The method of claim 1, wherein said at least one petrophysical property comprises formation factor, and further comprising, diffusing a paramagnetic ion into said fluid in said material during said imaging.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |