US3735828A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Accelerator for fishing jars
Assignee: Baker Hughes Oilfield Operations LLC
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Filing: 1972-03-15
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Granted: 1973-05-29
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Expires: 1992-03-15
Abstract
Abstract An accelerator for fishing jars for removing stuck objects from a well bore located above a drill collar string, the jar being located between a fishing tool and the drill collar string. A resiliently compressible body of rubber-like material is disposed in a pressure chamber in the accelerator containing a lubricating oil pressure transfer medium to apply pressure to all surfaces of the compressible body and reduce its volume when the fishing string is tensioned, the compressible body acting as a spring on expansion to accelerate the drill collar mass when the jar is released to produce the jarring action. The resilient material has a high impedance to the transmission of sound to improve jarring efficiency.
Inventors
- 👤 W O Houston Berryman
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 03:34
CPC Classifications
E; E21; E21B; E21B31/00; E21B31/107; E21B31/113; E21B17/00; E21B17/02; E21B17/04; E21B17/07
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
152 words
In an accelerator for fishing jars connectable to a fishing pipe string and to a drill collar string, the mass of which moves a jarring hammer into engagement with an anvil: inner and outer telescopic bodies, one of said bodies having means for connecting it to the fishing pipe string, the other of said bodies having means for connecting it to the drill collar string, means between said bodies defining a compression chamber containing a compressible medium, compression piston means operable upon telescopic extension of said bodies to compress said medium to store energy tending to effect telescopic contraction of said bodies and accelerate said drill collar string, said compressible medium comprising a body of resiliently compressible material and a fluid pressure transfer material in engagement therewith, the volume of said compressible material being decreased on its compression by said fluid pressure transfer material pressurized by relative movement between said telescopic bodies.
Claim 2
Dependent Claim
152 words
In an accelerator for fishing jars connectable to a fishing pipe string and to a drill collar string, the mass of which moves a jarring hammer into engagement with an anvil: inner and outer telescopic bodies, one of said bodies having means for connecting it to the fishing pipe string, the other of said bodies having means for connecting it to the drill collar string, means between said bodies defining a compression chamber containing a compressible medium, compression piston means operable upon telescopic extension of said bodies to compress said medium to store energy tending to effect telescopic contraction of said bodies and accelerate said drill collar string, said compressible medium comprising a body of resiliently compressible material and a fluid pressure transfer material in engagement therewith, the volume of said compressible material being decreased on its compression by said fluid pressure transfer material pressurized by relative movement between said telescopic bodies.
Claim 3
Dependent Claim
19 words
An accelerator as defined in claim 1, said body being composed of rubber-like material having a low bulk modulus.
Claim 4
Dependent Claim
14 words
An accelerator as defined in claim 1, said body being composed of silicone rubber.
Claim 5
Dependent Claim
27 words
An accelerator as defined in claim 1, said body having a high impedance to the transmission of sound therethrough as compared to the fluid pressure transfer material.
Claim 6
Dependent Claim
16 words
An accelerator as defined in claim 1, said fluid pressure transfer material comprising a lubricating oil.
Claim 7
Dependent Claim
24 words
An accelerator as defined in claim 1, said fluid pressure transfer material comprising a lubricating oil and said resiliently compressible body comprising rubber-like material.
Claim 8
Dependent Claim
24 words
An accelerator as defined in claim 1, said fluid pressure transfer material comprising a lubricating oil and said resiliently compressible body comprising silicone rubber.
Claim 9
Dependent Claim
45 words
An accelerator as defined in claim 1, said body having the characteristic that the product of its mass density times the speed of sound therethrough is lower than the product of the mass density times the speed of sound through said fluid pressure transfer material.
Claim 10
Dependent Claim
44 words
An accelerator as defined in claim 1, wherein said compression chamber is an annular chamber defined by opposing cylindrical walls of said telescopic bodies, said resiliently compressible body comprising a cylinder of rubber-like material disposed between said cylindrical walls and substantially filling said chamber.
Claim 11
Dependent Claim
53 words
An accelerator as defined in claim 1, wherein said compression chamber is an annular chamber defined by opposing cylindrical walls of said telescopic bodies, said resiliently compressible body comprising a cylinder of rubber-like material disposed between said cylindrical walls and having a radial thickness less than the radial distance between said opposing walls.
Claim 12
Dependent Claim
68 words
An accelerator as defined in claim 1, wherein said compression chamber is an annular chamber defined by opposing cylindrical walls of said telescopic bodies, said resiliently compressible body comprising a cylinder of rubber-like material disposed between said cylindrical walls and having a radial thickness less than the radial distance between said opposing walls, and coengageable stop means on said bodies for limiting telescopic extension of said telescopic bodies.
Claim 13
Dependent Claim
152 words
Apparatus for jarring a fish stuck in a well bore: comprising fishing tool means engageable with said fish, jarring means connected to said fishing tool means, a length of drill collars connected to said jarring means, accelerator means connected to said drill collars and having means for connecting said accelerator means to a pipe string by which said fishing tool means, said jarring means, Said length of drill collars and said accelerator means are adapted to be lowered in the well bore to engage said fishing tool means with said fish, said accelerator means being constructed so that the wave front created upon actuation and release of said jarring means in response to the tension in said accelerator means and said length of drill collars is reflected downwardly by said accelerator means, said accelerator means including a resiliently compressible elastomeric medium, and means for compressing said medium upon tensioning said accelerator means.
Claim 14
Dependent Claim
152 words
Apparatus for jarring a fish stuck in a well bore: comprising fishing tool means engageable with said fish, jarring means connected to said fishing tool means, a length of drill collars connected to said jarring means, accelerator means connected to said drill collars and having means for connecting said accelerator means to a pipe string by which said fishing tool means, said jarring means, Said length of drill collars and said accelerator means are adapted to be lowered in the well bore to engage said fishing tool means with said fish, said accelerator means being constructed so that the wave front created upon actuation and release of said jarring means in response to the tension in said accelerator means and said length of drill collars is reflected downwardly by said accelerator means, said accelerator means including a resiliently compressible elastomeric medium, and means for compressing said medium upon tensioning said accelerator means.
Claim 15
Dependent Claim
44 words
Apparatus for jarring a fish stuck in a well bore as defined in claim 12, wherein said means for compressing said medium comprises a compression chamber in said accelerator containing said elastomeric medium and a pressure transfer fluid for applying pressure to said medium.
Claim 16
Dependent Claim
55 words
Apparatus for jarring a fish stuck in a well bore as defined in claim 12, wherein said means for compressing said medium comprises a compression chamber in said accelerator containing said elastomeric medium and a pressure transfer fluid for applying pressure to said medium, said medium being composed of rubber having a low bulk modulus.
Claim 17
Dependent Claim
62 words
Apparatus for jarring a fish stuck in a well bore as defined in claim 12, wherein said means for compressing said medium comprises a compression chamber in said accelerator containing said elastomeric medium and a pressure transfer fluid for applying pressure to said medium, said medium being composed of rubber having a low bulk modulus and said fluid being a lubricating oil.
Claim 18
Dependent Claim
51 words
Apparatus for jarring a fish stuck in a well bore as defined in claim 12, wherein said means for compressing said medium comprises a compression chamber in said accelerator containing said elastomeric medium and a pressure transfer fluid for applying pressure to said medium, said medium being composed of silicone rubber.
Claim 19
Dependent Claim
60 words
Apparatus for jarring a fish stuck in a well bore as defined in claim 12, wherein said means for compressing said medium comprises a compression chamber in said accelerator containing said elastomeric medium and a pressure transfer fluid for applying pressure to said medium, said medium being composed of silicone rubber, and said pressure transfer fluid being a lubricating oil.
References Cited (Backward Citations)
US3472326A
Cited
US3570612A
Cited
US3539026A
Cited
US3539025A
Cited
US3606297A
Cited
US3642069A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1976-05-28 | 1976-11-27 | 1977-05-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1980-05-28 | 1980-11-27 | 1981-05-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1984-05-28 | 1984-11-27 | 1985-05-29 | $7700.00 | Window Closed / Lapsed |