Abstract:
An improved multi-faceted gripper block to improve the interchangeability of gripper blocks when the need arises to change the size of the diameter material (e.g. tubing, cable, plastic, wire, hoses, or pipe) or to improve the interchangeability of gripper blocks when the need arises to change one or more gripper blocks due to unservicability. The gripper block assembly comprises a carrier body being connectable to a gripper chain in an injector apparatus, a removable and rotatable gripper block insert having one or more longitudinal sides created with one of many types of known gripping channels or surfaces for engaging tubing or other or other such elongated items. The gripper block insert can be secured into the carrier and can be removed and then replaced or rotated without removing a serviceable carrier.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Application No. 61/464,157 filed on Mar. 1, 2011. 
     
    
     FIELD 
       [0002]    The present invention pertains to coiled tubing injection equipment used in the oil and gas exploration and production industry and more specifically pertains to coiled tubing gripper blocks that have at least two usable longsides and are installed in coiled tubing reeled tubing injection equipment. Such equipment is typically used to force coiled tubing into and out of oil and gas production wells. 
       BACKGROUND 
       [0003]    Coiled, or reeled, tubing has been used for years to force tubing into vertical as well as horizontal wellbores in order to perform a wide variety of operations such as completions, washing, circulating, production, production enhancement, cementing, inspecting, logging, etc. 
         [0004]    There are a number of patents issued on coiled tubing injectors and related equipment. Such injectors generally 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 engage the tubing 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. Upon 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 into or withdrawn from the wellbore, or until the gripper chains are no longer driven. 
         [0005]    In prior injector heads, various types of gripper blocks have been employed to force coiled tubing into and out of oil and gas wells. It is known to those skilled in the art that the gripper blocks are designed for a single specific outside diameter tubing size and that the gripper blocks deteriorate over time. That is, eventually gripper blocks must be replaced because of wear and/or they must be replaced if one wishes to run different sized tubing. The replacement process for the gripper blocks is very time consuming and laborious. Often, especially on larger sized coiled tubing injectors, the chains are quite cumbersome and heavy, sometimes several hundreds of pounds. The chain removal process may be necessary even if only one block is damaged or needs replacing. These factors consume time and resources that could be better used elsewhere during the actual drilling or servicing operations. Also, current injector designs that use gripper blocks only have one gripper surface per block, or more specifically, one longitudinal surface is created on only one facet of the block that will engage the tubing. 
         [0006]    Over the years, 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 gripper blocks, thus eliminating or limiting scarring and distortion of the tubing caused by gripper block engagement; providing the ability to accommodate minimal differing tubing diameters without having to change gripper blocks; reducing the weight of gripper blocks; and reducing the manufacturing costs of gripper blocks. 
         [0007]    Although, the gripper block disclosed in the U.S. Pat. No. 5,094,340 to Avakov has enjoyed commercial success; there remains a need for improving and enhancing certain characteristics of gripper blocks due to their critical importance in the operation of coiled tubing injector units. 
         [0008]    One such characteristic of prior known gripper blocks, such as the block disclosed in the U.S. Pat. Nos. 5,094,340 and 5,853,118 to Avakov is that the V-shaped singular faceted gripper block insert was designed to accommodate different outside diameters of tubing without having to change the gripper block to another size. Although these blocks are in use, the shortcomings include, but are not limited to, repeated misshaping of the tubing, scarring of the tubing, incorrect pressure on the blocks to grip the tubing, and the need to change the entire gripper block when changing over to another significantly different outer diameter size of tubing, or when only one gripper block needs to be changed due to failure or potential failure. The V-shaped blocks, used in pairs, have only four relatively small-in-area contact points with the tubing versus almost a full surface contact with a traditional U-shaped gripper block. To prevent slippage with the V-block, more pressure on the tubing is required versus the U-shaped block. Hence, the additional pressure on the four relatively small-in-area contact points can cause a deformation, such as squaring or denting, of the tubing. Each time the shape of the tubing changes it experiences material fatigue and shortens the life span of the tubing. When the need arises to change the gripper blocks, the coiled tubing operation has to be put on standby until the blocks, less than all the blocks, are changed in the field or back in another level of maintenance shop. This operation can take many hours, require the expense of another set of gripper blocks, and take larger and more valuable equipment off-line until the gripper blocks are changed. 
       SUMMARY OF THE INVENTION 
       [0009]    The present invention is directed toward an improved gripper block for use in grippingly engaging coil tubing, pipe, rod, cable, or like objects having various outside dimensions for ultimately applying a longitudinal load thereto. The improved gripper block is comprised of a carrier, an insertable gripper block, and can have a pin/bolt or other securing device. The carrier has an attachment point preferably at or near the center of the block body for providing a means of attachment to at least one endless chain of an injector apparatus. The improved gripper block is inserted into a carrier. The improved gripper block can have an attachment point whereby the cartridge is inserted into the carrier and held in place by a pin, bolt or other securing device. 
         [0010]    The multi-sided, or multi-faceted insertable gripper block, or cartridge, fits into a carrier that can be pinned or secured to the injector head chains. The blocks would be replaceable and easily removed by unpinning or unfastening, removing or rotating the gripper block, without the need to remove the carrier or the chains from the injector head. 
         [0011]    The blocks may be reversible or rotational, with 2 or more sides that can accommodate either the same size or different sized tubing. This would allow the same gripper blocks to be reversed and used when coiled tubing with a different outside diameter is needed during drilling and servicing operations. For example, a gripper block with 2 gripping sides may be designed to accommodate 1¼″ coiled tubing on one side and 1½″ coiled tubing on the other side. By simply reversing the side of the insertable gripper block, a single injector head can readily accommodate different sized tubing. Or, in the event that the block has the same size gripper, a damaged gripper block can merely be reversed and the injector head put back into service, thereby, drastically reducing the standby time and cost associated with well drilling and workover operations. 
         [0012]    The gripper block can be held in place by any number of methods including a pin, bolt or similar retaining mechanism, including a spring loaded pin that can be easily turned for quick release. 
         [0013]    The multiple sides of the reversible gripper blocks alleviate the problems of the time consuming and labor intensive chain removal process in the prior art. The present invention allows for quick and easy changing of the injector head blocks without necessitating the removal of the chains; thus, typically injector head gripper block change-out times can be reduced from 1-2 days to 1-2 hours. Furthermore, each gripping surface may have multiple grooves cut into it to aid in the gripping of the tubing but the number of grooves cut into each size gripper surface is specific to the tubing size for ease of identifying the tubing size. 
         [0014]    Further, the facets of the cartridge may each be created with a U-shaped, or any other suitable shape gripper engagement channel that has a gripper surface formed thereon; these gripper surfaces can be created with either different sized engagement channels, or a combination of 2 or more similar or different engagement channels, or even all engagement channels being of one size. The engagement can be continuous or near continuous between the gripper engagement channel and the tubing. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0015]      FIG. 1A  is a frontal view of a gripper block carrier body with a gripper block cartridge inserted into the gripper block carrier. 
           [0016]      FIG. 1B  is a sideview of a gripper block carrier body with a gripper block cartridge inserted into the gripper block carrier. 
           [0017]      FIG. 2A  is a top view of a gripper block, and in this case, the gripper block has two gripping surfaces. 
           [0018]      FIG. 2B  is a side view of a gripper block with two gripping channels shown for gripping and a hole for retaining the gripper block, such as with a pin. 
           [0019]      FIG. 2C  is an alternate side view of a gripper block with a shoulder visible. 
           [0020]      FIG. 3A  is a top view of a gripper block having four different gripper surfaces. 
           [0021]      FIG. 3B  is a frontal view of a gripper block, showing a channel shown for gripping and a hole for a retaining device to secure the gripper block into a gripper block carrier. 
           [0022]      FIG. 3C  is an alternate side view of a gripper block showing a gripping surface and hole for a retaining device to secure the gripper block to a carrier. 
       
    
    
     DETAILED DESCRIPTION 
       [0023]    Referring now to  FIGS. 1-3 , a first embodiment of a gripper block ( 2 ) constructed in accordance with the present invention is shown. As best seen in  FIGS. 2A and 2B , viewed along the longitudinal axis, the gripping surface ( 3 ) features is the inner curved surface of the channel ( 7 ) and the channel is generally U-shaped, but other suitable shapes may be used. Channel ( 7 ) is very common shape in the industry and is well known. The gripping surface ( 4 ) takes the shape of the channel ( 7 ). The channel is adapted to receive, for example, a specific outside diameter elongated object such as coiled tubing. The channel ( 7 ) permits the opposed gripping surfaces ( 3 ) of the channel to better engage the surface of coiled tubing as it is moved into or out of a wellbore. 
         [0024]    Still referring to  FIGS. 1 ,  2  and  3 , the channel ( 7 ) has a particular radius of curvature designed to accommodate an elongated object having a predetermined minimum outer diameter. This traditional style of the channel ( 7 ) by design is only for gripping one particular size of coiled tubing or other like elongated objects. The gripper block ( 2 ), in one embodiment may have only one of the multifaceted gripper block surfaces with a channel. In another embodiment, the gripper block ( 2 ) may have two or more of the multifaceted gripper block surfaces with channels. 
         [0025]    In one embodiment, the channels in the gripper block surface may be U-shaped and in another embodiment they may be another shape that better provided for a more grip on the coiled tubing or other elongated object. 
         [0026]    The gripper block facets, in one embodiment, would have all different sized channels, and in another embodiment, the gripper block facets would have all channels of one size or a combination of several like-sized channels and channels of another size. 
         [0027]    Referring now to  FIG. 3B , a side view of the gripper channel ( 7 ) is shown. The gripper channel ( 7 ) is usually constructed by casting, forging, or machining a single metal ingot formed of steel, titanium, or other suitable metal alloys. 
         [0028]    Referring now to  FIGS. 1A and 1B  is a view of the gripper block carrier body ( 1 ), with gripper block ( 2 ), inserted into a carrier ( 1 ). In this embodiment, the gripper block is secured into the carrier by means of a pin, bolt, or other such securing device (not shown) inserted through a hole in the carrier ( 5 ) and the gripper block ( 5 ). The round surface ( 7 ) of the gripper block ( 2 ) is visible, as is a shoulder ( 6 ) for guiding and centering the gripper block ( 2 ) in the gripper block carrier body ( 1 ). 
         [0029]      FIG. 2A  is a frontal view of the gripper block ( 2 ). In this case, the gripper block ( 2 ) has two channels ( 7 ). In another embodiment, the gripper block facets would have all channels of one size or a combination of several like-sized channels and channels of another size. 
         [0030]      FIG. 2B  is a side view of the gripper block ( 2 ) with two gripping channels ( 7 ) shown for gripping and a hole ( 5 ) for retaining the gripper block, such as with a pin (not shown). In this case, the gripper block ( 1 ) is shown with an inset shoulder ( 6 ) which mates to the gripper block carrier body (see  FIGS. 1A and 1B ) 
         [0031]      FIG. 2C  is an alternate side view of the gripper block ( 2 ). No gripping surface is evident as this is only a two sided gripper block; however, in this case, the shoulder ( 6 ) is visible. 
         [0032]      FIG. 3A  is a top view of a gripper block ( 2 ) having four different sized channels ( 7   a ,  7   b ,  7   c  and  7   d ) and the accompanying gripper surfaces ( 3   a ,  3   b ,  3   c  and  3   d ). 
         [0033]      FIG. 3B  is a frontal view of the gripper block ( 2 ), showing a channel ( 3 ) shown for gripping and a hole ( 5 ) for retaining the gripper block. 
         [0034]      FIG. 3C  is an alternate frontal view of the gripper block ( 2 ), showing a channel ( 7 ) and hole ( 5 ) for securing the gripper block ( 2 ) to the carrier body (see  FIG. 1 ). 
         [0035]    In certain embodiments wherein the tubular item being gripped by the gripper blocks may be sucker rod, hose, tubing other than coiled tubing, or other like items. That is, in other than coiled tubing operations in a petroleum-type well, this invention may be used on machines that use a gripper block system to convey, push, pull or otherwise control the movement of an item, such as tubing or other elongated objects. 
         [0036]    In at least one embodiment, the channel may be U-shaped, in another embodiment it may be V-shaped, in another embodiment it may have a shape to fit around a square, rectangular or other geometrical shape object. The invention is the multi-faceted gripper block assembly and not the well-known in the industry different shaped channels. 
         [0037]    Embodiments of the present invention may optionally include a device to secure the gripper block insert into the carriers. In one embodiment this may be a bolt and nut, in another embodiment it may be a pin such as a roll pin. In another embodiment it may be a spring-loaded pinning assembly to speed the removal and replacement of the securing device. In another embodiment it may be a method to secure the gripper block insert into the carrier without the use of a pinning or bolting device, such as secured with an adhesive material, suction, force fit or other such securing method. 
         [0038]    Embodiments of the present invention include a gripper block insert having a gripping surface shaped to form to a multi-component tubing arrangement. Non-limiting examples of a multi-component tubing arrangement can include one or more tubing strings encased in a containment device. The multi-component tubing arrangement can further include one or more control devices, such as electrical cables that can provide power or communication downhole. The multi-component tubing arrangement can be arranged in various shapes and sizes, such as non-limiting examples of tubular, oval, rectangular, triangular, or other shapes. 
         [0039]    Embodiments of the present invention can include a surface treatment on the inside of the carrier and/or one or more of the surfaces of the block. The surface treatment can be an elastomer or other material that can absorb impact forces between the block and carrier. 
         [0040]    An embodiment may include a method to secure the gripper block insert into the carrier without the use of a pinning or bolting device. The gripper block may optionally be secured with an adhesive material, suction, force fit or other such securing methods. 
         [0041]    Use of the term “optionally” with respect to any element of a claim is intended to mean that the subject element is required, or alternatively, is not required. Both alternatives are intended to be within the scope of the claim. Use of broader terms such as comprises, includes, having, etc. should be understood to provide support for narrower terms such as consisting of, consisting essentially of, comprised substantially of, etc. 
         [0042]    Depending on the context, all references herein to the “invention” may in some cases refer to certain specific embodiments only. In other cases it may refer to subject matter recited in one or more, but not necessarily all, of the claims. While the foregoing is directed to embodiments, versions and examples of the present invention, which are included to enable a person of ordinary skill in the art to make and use the inventions when the information in this patent is combined with available information and technology, the inventions are not limited to only these particular embodiments, versions and examples. Other and further embodiments, versions and examples of the invention may be devised without departing from the basic scope thereof and the scope thereof is determined by the claims that follow.