US3684038A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Balanced pressure drilling
Assignee: Mobil Oil AS
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Filing: 1971-02-23
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Granted: 1972-08-15
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Expires: 1991-02-23
Abstract
Abstract This specification discloses a rotary method of drilling a well into the earth. A portion of the drilling mud that is circulated through the well is treated at selected times, which portion is separated into two streams, a high density slurry stream containing a heavy solids phase, and a low density effluent stream containing a light solids phase. The effluent stream is recombined into the drilling mud and the high density slurry stream is stored, thereby decreasing the density of the drilling mud circulated through the well. At other selected times the high density slurry is flowed into the drilling mud to increase the density thereof.
Inventors
- 👤 Murrell D Nelson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-25 17:01
CPC Classifications
E; E21; E21B; E21B21/00; E21B21/06; E21B21/063
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
184 words
In a method of drilling a well into the earth wherein a drill string is located in said well and an active drilling mud system is employed in the circulation of drilling mud between the surface of the earth and the bottom of the well, said drilling mud in said drilling mud system being comprised of a heavy solids phase and a light solids phase, the improvement comprising: a. treating a portiOn of said drilling mud in said drilling mud system to separate said portion into a high density slurry stream containing said heavy solids phase and into a low density effluent stream containing said light solids phase; b. reducing the density of said drilling mud in said active drilling mud system by flowing said low density effluent stream containing said light solids phase into said active drilling mud system; c. concomitantly with step (a) flowing said high density slurry stream into storage; and d. thereafter increasing the density of said drilling mud in said active drilling mud system by flowing said high density slurry stream from storage into said active drilling mud system.
Claim 2
Dependent Claim
184 words
In a method of drilling a well into the earth wherein a drill string is located in said well and an active drilling mud system is employed in the circulation of drilling mud between the surface of the earth and the bottom of the well, said drilling mud in said drilling mud system being comprised of a heavy solids phase and a light solids phase, the improvement comprising: a. treating a portiOn of said drilling mud in said drilling mud system to separate said portion into a high density slurry stream containing said heavy solids phase and into a low density effluent stream containing said light solids phase; b. reducing the density of said drilling mud in said active drilling mud system by flowing said low density effluent stream containing said light solids phase into said active drilling mud system; c. concomitantly with step (a) flowing said high density slurry stream into storage; and d. thereafter increasing the density of said drilling mud in said active drilling mud system by flowing said high density slurry stream from storage into said active drilling mud system.
Claim 3
Dependent Claim
39 words
The method of claim 1 wherein said high density slurry stream is flowed from storage into said active drilling mud system at a rate to uniformly increase the density of said drilling mud in said active drilling mud system.
Claim 4
Dependent Claim
36 words
The method of claim 1 wherein said high density slurry stream is flowed from storage at a uniform rate into said active drilling mud system during one complete circulation cycle of said active drilling mud system.
Claim 5
Dependent Claim
41 words
The method of claim 1 wherein said high density slurry stream is flowed from storage into said drill string to establish a mud column of said high density slurry in said well thereby increasing the hydrostatic pressure applied in said well.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1975-08-15 | 1976-02-14 | 1976-08-15 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1979-08-15 | 1980-02-14 | 1980-08-15 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1983-08-15 | 1984-02-14 | 1984-08-15 | $7700.00 | Window Closed / Lapsed |