US4473124A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method for operating rotary drilling under conditions of high cuttings transport efficiency
Assignee: Mobil Oil AS
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Filing: 1983-05-02
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Granted: 1984-09-25
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Expires: 2003-05-02
Abstract
Abstract In a rotary method of drilling a well into the earth employing a drilling mud system, the transport ratio (hole cleaning efficiency) is increased by increasing the yield point to plastic viscosity ratio of the drilling fluid while maintaining the plastic viscosity constant. In a preferred embodiment, the plastic viscosity is varied within the range of 7.5 to 30 centipoises and the yield point to plastic viscosity ratio is varied within the range of 0.20 to 1.5.
Inventors
- 👤 Joseph G. Savins
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 11:55
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/08
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
78 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid between the surface of the earth and the bottom of the well, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a constant plastic viscosity and increasing the ratio of yield point to plastic viscosity within a predetermined range thereby increasing transport ratio.
Claim 2
Independent Claim
78 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid between the surface of the earth and the bottom of the well, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a constant plastic viscosity and increasing the ratio of yield point to plastic viscosity within a predetermined range thereby increasing transport ratio.
Claim 3
Dependent Claim
33 words
The method of claim 1 wherein the plastic viscosity is maintained within the range of 15 to 30 centipoises and the yield point to plastic viscosity ratio is increased from 0.20 to 1.5.
Claim 4
Independent Claim
114 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid into said drill string and upwardly through the annular space between the drill string and the wall of the well, said well being drilled under laminar flow conditions with a wide annulus in a highly deviated wellbore, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a plastic viscosity of about 15 centipoises and increasing the yield point to plastic viscosity ratio from about 0.4 to about 1.5 thereby increasing the transport ratio from about 25% to about 40%.
Claim 5
Independent Claim
114 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid into said drill string and upwardly through the annular space between the drill string and the wall of the well, said well being drilled under laminar flow conditions with a wide annulus in a highly deviated wellbore, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a plastic viscosity of about 15 centipoises and increasing the yield point to plastic viscosity ratio from about 0.4 to about 1.5 thereby increasing the transport ratio from about 25% to about 40%.
Claim 6
Independent Claim
114 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid into said drill string and upwardly through the annular space between the drill string and the wall of the well, said well being drilled under laminar flow conditions with a narrow annulus in a highly deviated wellbore, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a plastic viscosity of about 30 centipoises and increasing the yield point to plastic viscosity ratio from about 0.5 to about 1.5 thereby increasing the transport ratio from about 25% to about 40%.
Claim 7
Independent Claim
114 words
A method of drilling a well into the earth wherein a drill string is located in said well and an active drilling fluid system is employed in the circulation of drilling fluid into said drill string and upwardly through the annular space between the drill string and the wall of the well, said well being drilled under laminar flow conditions with a narrow annulus in a highly deviated wellbore, the improvement comprising employing a drilling fluid exhibiting plastic flow maintained at a plastic viscosity of about 30 centipoises and increasing the yield point to plastic viscosity ratio from about 0.5 to about 1.5 thereby increasing the transport ratio from about 25% to about 40%.
References Cited (Backward Citations)
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US3860070A
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US3985659A
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US4330414A
Cited
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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) | 1987-09-25 | 1988-03-26 | 1988-09-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1991-09-25 | 1992-03-26 | 1992-09-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1995-09-25 | 1996-03-26 | 1996-09-25 | $7700.00 | Window Closed / Lapsed |