Patent US4064749A successfully refreshed from Google Patents.
US4064749A
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Method and system for determining formation porosity
Assignee: Texaco Inc
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Filing: 1976-11-11
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Granted: 1977-12-27
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Expires: 1996-11-11
Abstract
Abstract A method and/or system for measuring formation porosity from drilling response. It involves measuring a number of drilling parameters and includes determination of tooth dullness as well as determining a reference torque empirically. One of the drilling parameters is the torque applied to the drill string.
Inventors
- 👤 Robert W. Pittman
- 👤 Chester E. Hermes
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 23:07
CPC Classifications
E; E21; E21B; E21B49/00; E21B49/003; E21B12/00; E21B12/02; E21B44/00
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
90 words
Method for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled, comprising the steps of measuring the revolutions of said bit, measuring the depth of said bit in the borehole, measuring the weight on said bit, determining the tooth dullness of said bit, measuring the torque applied to said drill string, determining a reference torque empirically, and determining said porosity of combining said measurements and determinations.
Claim 2
Dependent Claim
90 words
Method for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled, comprising the steps of measuring the revolutions of said bit, measuring the depth of said bit in the borehole, measuring the weight on said bit, determining the tooth dullness of said bit, measuring the torque applied to said drill string, determining a reference torque empirically, and determining said porosity of combining said measurements and determinations.
Claim 3
Dependent Claim
19 words
Method according to claim 1, wherein said step of determining a reference torque comprises determining viscous drill string torque.
Claim 4
Dependent Claim
25 words
Method according to claim 2, wherein said step of determining a reference torque also comprises making a series of short duration weight vs. torque measurements.
Claim 5
Dependent Claim
80 words
Method according to claim 3, wherein said step of determining said porosity is carried out in accordance with the equation ##EQU5## where: μ = ratio of total porosity to the porosity effecting the atmospheric compressive strength ln = natural logarithm of N = rotational speed of bit T = torque P e = effective confining pressure D = bit diameter R = penetration rate W = weight on bit σca max = atmospheric compressive strength extrapolated back to zero porosity.
Claim 6
Independent Claim
97 words
A system for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled, comprising in combination means for measuring the revolutions of said bit, means for measuring the depth of said bit in the borehole, means for determining the tooth dullness of said bit, means for measuring the torque applied to said drill string, and means for correlating said measurements and determination in conjunction with an empirical reference torque to provide a porosity log.
Claim 7
Independent Claim
97 words
A system for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled, comprising in combination means for measuring the revolutions of said bit, means for measuring the depth of said bit in the borehole, means for determining the tooth dullness of said bit, means for measuring the torque applied to said drill string, and means for correlating said measurements and determination in conjunction with an empirical reference torque to provide a porosity log.
Claim 8
Dependent Claim
15 words
A system according to claim 5, wherein said means for correlating comprises an electronic calculator.
Claim 9
Dependent Claim
16 words
A system according to claim 6, wherein said means for measuring the revolutions comprises a tachometer.
Claim 10
Independent Claim
191 words
A system for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled and wherein the torque applied to rotate said drill string is measured, comprising in combination means for measuring the revolutions of said bit comprising a tachometer, means for measuring the depth of said bit in the borehole, means for determining the tooth dullness of said bit, means for correlating said measurements and determination in accordance with the equation ##EQU6## wherein: μ = ratio of total porosity to the porosity effecting the atmospheric compressive strength ln = natural logarithm of N = rotational speed of bit T = torque P e = effective confining pressure D = bit diameter R = penetration rate W = weight on bit σca max = atmospheric compressive strength extrapolated back to zero porosity, to represent a porosity parameter of the formation, means for recording said porosity parameter on a record medium as it is advanced, and means for advancing said record medium in accordance with the depth of said bit.
Claim 11
Independent Claim
191 words
A system for determining porosity of a formation from drilling response, wherein a bit is attached to the lower end of a drill string that is rotated while the downward force on said bit is controlled and wherein the torque applied to rotate said drill string is measured, comprising in combination means for measuring the revolutions of said bit comprising a tachometer, means for measuring the depth of said bit in the borehole, means for determining the tooth dullness of said bit, means for correlating said measurements and determination in accordance with the equation ##EQU6## wherein: μ = ratio of total porosity to the porosity effecting the atmospheric compressive strength ln = natural logarithm of N = rotational speed of bit T = torque P e = effective confining pressure D = bit diameter R = penetration rate W = weight on bit σca max = atmospheric compressive strength extrapolated back to zero porosity, to represent a porosity parameter of the formation, means for recording said porosity parameter on a record medium as it is advanced, and means for advancing said record medium in accordance with the depth of said bit.
References Cited (Backward Citations)
US3898880A
Cited
US3916684A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-12-26 | 1981-06-27 | 1981-12-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-12-26 | 1985-06-27 | 1985-12-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-12-26 | 1989-06-27 | 1989-12-27 | $7700.00 | Window Closed / Lapsed |