Multiple contour coiled tubing gripper block

Details Multiple contour coiled tubing gripper block Multiple contour coiled tubing gripper block

1999-03-17

2001-05-15

Walsh, Donald P. (Department: 3653)

Advancing material of indeterminate length

By orbitally traveling material-engaging surface

Including details of roll or mount

C226S173000, C166S077300

Reexamination Certificate

active

06230955

ABSTRACT:

BACKGROUND OF THE INVENTION
This invention relates to coiled tubing injection equipment used in the oil and gas industry and more particularly to gripper blocks used in coiled tubing injectors. As is well known in the art, coiled tubing injectors are typically used to move coiled tubing into and out of oil and gas wellbores.
Reeled or coiled tubing has been run into wells for many years for performing certain downhole operations, including but not limited to completions, washing, circulating, production, production enhancement, cementing, inspecting and logging. There are a number of patents issued on coiled tubing injectors and related equipment. Such injectors typically use a pair of opposed endless gripper chains mounted in a common plane. The gripper chains are normally made up of links, rollers and gripper blocks. Opposed gripper blocks on the endless chains opposingly engage the tubing so as to firmly grasp the tubing in such a way that the gripper blocks will force the tubing into or out of a wellbore when the gripper chains are driven. On setting the gripper chains into motion and upon each opposing pair of gripper blocks releasing their hold on the tubing, another pair of opposed gripper blocks grippingly engage the tubing and the cycle continues until a desired amount of tubing has been inserted or withdrawn from the wellbore, or until the gripper chains are no longer driven.
A variety of gripper blocks have been developed to improve the performance of coiled tubing injector units. Such improvements include designs directed to increasing the load carrying capability of the gripper block, eliminating or limiting scarring and distortion of the tubing caused by gripper block engagement, providing the ability to accommodate differing tubing diameters without having to change gripper blocks, reducing the weight of gripper blocks and reducing the manufacturing costs of gripper blocks. Such prior art gripper blocks are disclosed in U.S. Pat. No. 5,094,340 to Avakov, issued Mar. 10, 1992, and U.S. Pat. No. 5,853,118 to Avakov issued Dec. 29, 1998, both assigned to the assignee of the present invention, the details of both of which are incorporated herein by reference.
The gripper blocks described in the aforementioned patents have great utility in that they will accommodate different tubing diameters without having to change gripper blocks. As depicted in
FIG. 1
, a prior art gripper block
2
has opposite sides
4
, opposite ends
6
and
8
positioned along an imaginary longitudinal axis, and a gripping region
10
running parallel to the longitudinal axis for gripping a section of continuous tubing, tube or other article that is to be injected or withdrawn, or otherwise have a force imparted thereon. End
8
has a wedge-shaped tongue
12
extending therefrom. End
6
has ears
9
extending therefrom defining recessed region
11
therebetween. A single borehole, or pin hole
14
extends through the gripper block body
2
.
Tubing gripping region
10
located on the upper portion of block
2
includes a pair of angled or sloped gripping surfaces
16
which diverge away from a base area to form a generally V-shaped profile when viewed from either end of block
2
. Surfaces
16
and
18
comprise alternating ridges and grooves
20
and
22
, respectively, configured to resemble acme-type threads.
The prior art gripper block described in
FIG. 1
can be effectively utilized to move tubing or other elongated objects of various diameters in and out of a wellbore and has enjoyed commercial success. Typically, the coiled tubing utilized with such prior art gripper blocks is a steel coiled tubing which can be utilized to perform a wide variety of operations in a wellbore. However, it has been found that using such gripper blocks to move composite coiled tubing is not as efficient as desired, since the sloped planar surfaces in the gripping region often cause damage to composite coiled tubing.
Composite coiled tubing is lighter than steel coiled tubing and is easier to force into wells that deviate from the vertical, including horizontal wells. Thus, there are times when it is preferable to use a composite coiled tubing to perform a desired operation, and other times when it may be preferable to use a steel coiled tubing. Although the prior art gripper blocks described herein work adequately with steel coiled tubing, they are not effective for use with composite coiled tubing. If it is desired to perform an operation with composite coiled tubing, a different gripper block must be used. The injector unit must therefore be disassembled, and gripper blocks compatible with composite tubing must be installed. If it is later desired to utilize steel coiled tubing, the composite compatible gripper blocks must be replaced with blocks designed to move steel coiled tubing.
Thus there is a need for a gripper block which has a gripping surface that is capable of accommodating varying sizes of coiled tubing and that is also capable of accommodating different material types such as steel and composite coiled tubing.
SUMMARY OF THE INVENTION
The present invention is directed toward an improved gripper block for use in grippingly engaging coiled tubing, pipe, rod, cable or like objects having various outside diameters. Specifically, the present invention is directed toward an improved gripper block for use in grippingly engaging both composite coiled tubing and steel coiled tubing. The improved gripper block has a gripping region defined thereon which may comprise first and second gripping portions.
The first gripping portion comprises a pair of sloped planar gripping surfaces. The second gripping portion comprises a curved gripping surface. The sloped planar gripping surfaces are preferably sloped at an angle of approximately 90° from each other. The sloped gripping surfaces comprise a plurality of ridges having grooves therebetween. The curved gripping surface likewise has ridges and grooves defined thereon. Preferably, the ridges and grooves on the curved gripping surface are tapered such that at a center of the curved gripping surface, no groove or ridge exists. The curved gripping surface, and preferably the ridges thereon have a first radius of curvature. The grooves are defined by a second radius of curvature. The sloped planar gripping surfaces diverge outwardly from outer ends of the curved gripping surface.
The curved gripping surface will engage a tubing having a first diameter in such a way as to move the tubing in and out of a wellbore. The curved gripping surface is uniquely adapted to engage composite coiled tubing and to move the composite coiled tubing without damaging the tubing. Preferably, the tubing engaged by the curved gripping surface has a radius slightly smaller than or substantially identical to the first radius of curvature of the curved gripping surface.
The sloped planar gripping surfaces will engage tubing of various diameters greater than the diameter of the tubing engaged by the curved gripping surface. Thus, the sloped planar gripping surfaces will engage tubing having a diameter falling in the range from a second diameter to a third diameter wherein the third diameter is greater than the second diameter and the second diameter is greater than the diameter of the tubing engaged by the curved gripping surface.


REFERENCES:
patent: 874982 (1907-12-01), Norton
patent: 1321463 (1919-10-01), Lloyd
patent: 1355449 (1920-10-01), Campbell
patent: 2679924 (1954-06-01), Powell
patent: 2752797 (1956-07-01), Sherwin
patent: 3021939 (1962-02-01), Hopkins
patent: 3108682 (1963-10-01), Zipper
patent: 3258110 (1966-06-01), Pilcher
patent: 3285485 (1966-11-01), Slator
patent: 3559905 (1971-02-01), Palynchuk
patent: 3606810 (1971-09-01), Kozij
patent: 3615154 (1971-10-01), Pryor
patent: 3754474 (1973-08-01), Palynchuk
patent: 3841407 (1974-10-01), Bozeman
patent: 3869038 (1975-03-01), Piper et al.
patent: 3945547 (1976-03-01), Ledebur
patent: 4064987 (1977-12-01), Rowan
patent: 4171738 (1979-10-01), Lieberman
patent: 4515220 (1985-05-01), Sizer et al.
patent: 4585061 (1986-04-01),

Affiliated with

Also associated with

Rating

Multiple contour coiled tubing gripper block does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Multiple contour coiled tubing gripper block, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Multiple contour coiled tubing gripper block will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFUS-PAI-O-2531873