Tools – Wrench – screwdriver – or driver therefor – Machine
Reexamination Certificate
1999-07-29
2001-12-25
Hail, III, Joseph H. (Department: 3723)
Tools
Wrench, screwdriver, or driver therefor
Machine
C081S057180, C081S476000
Reexamination Certificate
active
06332377
ABSTRACT:
This invention relates to a gripping arrangement for gripping casing, a jaw assembly provided with such a gripping arrangement, and a tong fitted with two or more such jaw assemblies.
During the construction of oil and gas wells a wellbore is drilled into the ground. A string of tubulars, generally referred to as “casing” is then lowered down the wellbore and the annular space between the wellbore and the casing filled with cement.
Each length of casing is screwed to the next and tightened to a predetermined torque using a device known as a “tong”. The tong comprises two or more jaw assemblies which can be activated to grip the casing and then rotate it about its longitudinal axis.
Historically, casing was made of thick walled steel pipe which was extremely robust. Such casing could easily be gripped by conventional jaw assemblies which were provided with teeth which penetrated the surface of the casing to obtain the desired grip.
As wells became deeper and deviated drilling became more common conventional casing was replaced by “premium” casing which is significantly lighter than conventional casing. The walls of such casing could easily be damaged by the teeth of conventional jaw assemblies and various new jaw assemblies were developed to grip premium casing whilst minimising damage thereto.
One such jaw assembly, which has been developed by the present applicants, and which is described in EP-A-0 482 158 comprises a gripping arrangement having an elastomeric substrate in which are embedded a plurality of needles the tips of which project radially inwardly to grip the casing. This jaw assembly has excellent gripping properties and causes minimal damage to the surface of premium casing. However, it is relatively expensive to manufacture and prone to the formation of “bald” spots, particularly if the casing has an irregular surface. The formation of bald spots necessitates premature replacement of the gripping arrangement.
With a view to providing a less expensive arrangement which is less prone to the formation of bald spots the present invention provides a gripping arrangement for gripping casing characterised in that it is sufficiently flexible to conform to said casing and is substantially inelastic.
It should be noted that traditional jaws are inelastic and incapable of conforming to the outside of a casing whilst the gripping arrangement of EP-A-0 482 158 is, because of its elastomeric substrate, elastic and any circumferential force applied to a needle is not distributed directly to adjacent needles.
In one embodiment the gripping arrangement comprises a sheet of grit which is preferably bonded to a carrier plate.
In another embodiment the gripping arrangement comprises a layer of flexible material having a surface with ridges and valleys, for example in the fashion of the surface of a file. The flexible material is preferably metal, for example sheet steel having a thickness of 1.5 mm. The layer of flexible material may be used in conjunction with a carrier plate or on its own.
In a further embodiment the gripping arrangement may comprise a layer of perforate material one of both surfaces of which are preferably coated with grit to facilitate adhesion. The layer will typically be formed from metal, for example sheet steel having a thickness of 1.5 mm. The layer may be used in conjunction with a carrier plate or used on its own.
In yet another embodiment the gripping arrangement may comprise a layer of expanded mesh which has been flattened. One or both surfaces of the expanded mesh may be coated with grit and the layer may be used in conjunction with a carrier plate or used on its own.
The grit may comprise, for example, diamond dust, particles of silicon, zircon, tungsten carbide and mixtures thereof.
The gripping arrangement may comprise end plates which are attached to the carrier plate.
Preferably, the carrier plate is provided with side flanges for insertion into a jaw holder.
The present invention also provides a jaw assembly fitted with a gripping arrangement in accordance with the present invention.
Preferably, the jaw assembly includes a jaw holder having an arcuate recess which accommodates an arcuate pad of resilient elastomeric material which supports said gripping arrangement.
Advantageously, at least one shim is provided which is disposed between said arcuate pad of resilient elastomeric material and said gripping arrangement. The shim will be flexible and generally from 0.5 mm to 1.0 mm thick and made from sheet steel.
The present invention also provides a tong fitted with at least two jaw assemblies in accordance with the present invention.
REFERENCES:
patent: Re. 31993 (1985-10-01), Wesch, Jr.
patent: D. 314896 (1991-02-01), Haynes
patent: 1719533 (1929-07-01), Cady
patent: 2520435 (1950-08-01), Roman
patent: 2962919 (1960-12-01), Grundmann et al.
patent: 3015142 (1962-02-01), Rasanoff et al.
patent: 3019680 (1962-02-01), Daugherty et al.
patent: 3021149 (1962-06-01), Griffin
patent: 3256757 (1966-06-01), Kochaver
patent: 3272038 (1966-09-01), Burstall
patent: 3531836 (1970-10-01), Crickmer
patent: 3589742 (1971-06-01), Flick
patent: 4315447 (1982-02-01), Tartaglia et al.
patent: 4576067 (1986-03-01), Buck
patent: 4631987 (1986-12-01), Buck
patent: 4649777 (1987-03-01), Buck
patent: 4697830 (1987-10-01), Wood et al.
patent: 4709599 (1987-12-01), Buck
patent: 4712284 (1987-12-01), Coyle, Sr. et al.
patent: 4774860 (1988-10-01), Hawke
patent: 4836064 (1989-06-01), Slator
patent: 5150642 (1992-09-01), Moody et al.
patent: 5221099 (1993-06-01), Jansch
patent: 5410924 (1995-05-01), Krasnov
patent: 5451084 (1995-09-01), Jansch
patent: 5484222 (1996-01-01), Schulze-Beckinghausen
patent: 5669653 (1997-09-01), Penisson
patent: 5671961 (1997-09-01), Buck
patent: 5845549 (1998-12-01), Bouligny
patent: 5911796 (1999-06-01), Buck
patent: 1060644 (1963-10-01), None
patent: 1364388 (1972-09-01), None
patent: 2101197 A (1982-05-01), None
patent: 2307939 A (1995-09-01), None
patent: PCT/US90/04616 (1990-08-01), None
Recent Advances In The Handling, Makeup, and Running of C.R.A. Tubulars, Harris et al, SPE 36754, 1993.
Spinnerhawk and Mini-Spinner, Weatherford, 1983.
Tubing Tongs For Well Servicing and Workover, Weatherford, 1995.
Precision Makeup Systems, Weatherford, 1990.
Carlsson Andreas
Pietras Bernd-Georg
Schulze-Beckinghausen Joerg-Erich
Berry Jr. Willie
Hail, III Joseph H.
Moser, Patterson & Sheridan L.L.P.
Weatherford / Lamb, Inc.
LandOfFree
Gripping arrangement for gripping casing does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Gripping arrangement for gripping casing, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Gripping arrangement for gripping casing will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2586124