Patent US3948575A successfully refreshed from Google Patents.
US3948575A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Drill pipe and drill collar containing molded casing protector and method of protecting casing therewith
Assignee: Individual
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Filing: 1974-10-24
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Granted: 1976-04-06
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Expires: 1994-10-24
Abstract
Abstract A string of drill pipe having lengths of pipe connected by enlarged couplings and operable in a well casing has located between couplings casing protectors comprising annular rings of an oil impermeable and gas impermeable synthetic resin molded around the drill pipe. The casing protectors have a slick, hard outer surface for substantially non-damaging contact with the casing. The casing protectors can be molded about drill collar to also provide protection against damage to well casing.
Inventors
- 👤 Eugene P. Rosser
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 21:37
CPC Classifications
E; E21; E21B; E21B17/00; E21B17/10; E21B17/1078
Claims Analysis
Total Claims: 21
Claim 1
Independent Claim
81 words
A string of drill pipe having lengths of pipe connected by enlarged couplings and operable in a well casing, said string of drill pipe having between couplings casing protectors comprising continuous annular rings of an oil impermeable and gas impermeable synthetic resin molded directly around said drill pipe, the outside diameter of said casing protectors being greater than the outside diameter of said enlarged couplings, said casing protectors having a slick, hard outer surface for substantially non-damaging contact with said casing.
Claim 2
Dependent Claim
81 words
A string of drill pipe having lengths of pipe connected by enlarged couplings and operable in a well casing, said string of drill pipe having between couplings casing protectors comprising continuous annular rings of an oil impermeable and gas impermeable synthetic resin molded directly around said drill pipe, the outside diameter of said casing protectors being greater than the outside diameter of said enlarged couplings, said casing protectors having a slick, hard outer surface for substantially non-damaging contact with said casing.
Claim 3
Dependent Claim
17 words
The string of drill pipe of claim 1, wherein said casing protector comprises a molded epoxy resin.
Claim 4
Dependent Claim
22 words
The string of drill pipe of claim 1, wherein said molded casing protector contains a minor amount of a lubricity increasing additive.
Claim 5
Dependent Claim
17 words
The string of drill pipe of claim 1, wherein said casing protector has an uninterrupted outer surface.
Claim 6
Dependent Claim
21 words
The string of drill pipe of claim 1, wherein the outer surface of said casing protector includes at least one groove.
Claim 7
Dependent Claim
21 words
The string of drill pipe of claim 5, wherein said groove is helically disposed around the surface of said casing protector.
Claim 8
Dependent Claim
82 words
A drill pipe having an enlarged box end and an enlarged pin end and molded thereto, around the entire periphery thereof, between said box and pin ends, a casing protector comprising a continuous annular ring of oil impermeable and gas impermeable synthetic resin, the outer diameter of said casing protector being greater than the outer diameter of both said enlarged box end and enlarged pin end, said casing protector having a slick, hard outer surface for substantially non-damaging contact with well casing.
Claim 9
Dependent Claim
82 words
A drill pipe having an enlarged box end and an enlarged pin end and molded thereto, around the entire periphery thereof, between said box and pin ends, a casing protector comprising a continuous annular ring of oil impermeable and gas impermeable synthetic resin, the outer diameter of said casing protector being greater than the outer diameter of both said enlarged box end and enlarged pin end, said casing protector having a slick, hard outer surface for substantially non-damaging contact with well casing.
Claim 10
Dependent Claim
15 words
The drill pipe of claim 7, wherein said casing protector comprises a molded epoxy resin.
Claim 11
Dependent Claim
20 words
The drill pipe of claim 7, wherein said molded casing protector contains a minor amount of a lubricity increasing additive.
Claim 12
Dependent Claim
15 words
The drill pipe of claim 7, wherein said casing protector has an uninterrupted outer surface.
Claim 13
Dependent Claim
19 words
The drill pipe of claim 7, wherein the outer surface of said casing protector includes at least one groove.
Claim 14
Dependent Claim
19 words
The drill pipe of claim 11, wherein said groove is helically disposed around the surface of said casing protector.
Claim 15
Dependent Claim
44 words
A drill collar having molded directly thereto, around the entire periphery thereof, a casing protector comprising a continuous annular ring of oil impermeable and gas impermeable synthetic resin, said casing protector having a slick, hard outer surface for substantially non-damaging contact with well casing.
Claim 16
Dependent Claim
44 words
A drill collar having molded directly thereto, around the entire periphery thereof, a casing protector comprising a continuous annular ring of oil impermeable and gas impermeable synthetic resin, said casing protector having a slick, hard outer surface for substantially non-damaging contact with well casing.
Claim 17
Dependent Claim
15 words
The drill collar of claim 13, wherein said casing protector comprises a molded epoxy resin.
Claim 18
Dependent Claim
20 words
The drill collar of claim 13, wherein said molding casing protector contains a minor amount of a lubricity increasing additive.
Claim 19
Dependent Claim
15 words
The drill collar of claim 13, wherein said casing protector has an uninterrupted outer surface.
Claim 20
Dependent Claim
19 words
The drill collar of claim 13, wherein the outer surface of said casing protector includes at least one groove.
Claim 21
Dependent Claim
19 words
The drill collar of claim 17, wherein said groove is helically disposed around the surface of said casing protector.
References Cited (Backward Citations)
US3063760A
Cited
US3560060A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1979-04-06 | 1979-10-06 | 1980-04-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1983-04-06 | 1983-10-06 | 1984-04-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1987-04-06 | 1987-10-06 | 1988-04-06 | $7700.00 | Window Closed / Lapsed |