APPARATUS, SYSTEM AND METHOD FOR CONNECTING COILED TUBING TO A MEMBER

Abstract: An apparatus for connecting coiled tubing to a member, said apparatus comprising a first connecting means (30) for connection to coiled tubing, a second connecting means (60) for connection to a member characterised in that said apparatus allows movement therebetween. A system comprising the apparatus of the invention, said system comprising coiled tubing (106). A method for connecting coiled tubing to a member, using the apparatus of the invention, the method comprising the step of connecting coiled tubing and member to said apparatus whereupon lateral movement therebetween is facilitated.

Description: APPARATUS, SYSTEM AND METHOD FOR CONNECTING COILED TUBING TO A MEMBER This invention relates to an apparatus and method for connecting coiled tubing to a member, and particularly but not exclusively, relates to a connector for connecting coiled tubing to a rigid tubular or tool for use in the construction, maintenance or repair of an oil or gas well . Coiled tubing is used in many systems instead of jointed pipe or jointed tubing, as drill pipe, production tubing, or casing, during well drilling or servicing operations, in the construction, maintenance and repair of oil or gas wells . Coiled tubing may be used on a drilling rig or a workover rig. Various kinds of downhole equipment tools , bottom hole assemblies , stabilizers , drill motors , and bits are attached to the end of coiled tubing. Coiled tubing (for example, of a relatively small diameter, such as 2.5cm (1 inch) provides the maximum amount of tubing which can be mounted on a reel, but such small diameter coiled tubing: limits the flow of fluids ; limits the amount of compression force that can be transmitted through the string of tubing in the well ; limits the amount of tension that can be placed on the string of tubing; limits the amount of torque that the tubing can withstand; limits the type and weight of tools that may be used; and limits the length of tubing that may be used. Larger sizes of coiled tubing are also used in diameters ranging up to 9cm (3.5 inches) and larger, but the use of such coiled tubing with small reels and associated handling apparatus may be difficult. Typical prior art coiled tubing handling equipment includes a reel of coiled tubing mounted on a platform or vehicle, an injector to run the tubing into and out of - 2 - the well, a gooseneck adjacent and/or permanently affixed to the injector for guiding the coiled tubing between the reel and the injector, a lifting device to support the injector and the gooseneck, a hydraulic power pack to provide power to the reel and the injector and to other hydraulic equipment, and surface equipment such as strippers and blow-out preventers to seal around the coiled tubing as it is run into and out of the well. A trailer or skid is used to transport the reel which may be of various sizes, depending upon the size of the coiled tubing to be reeled thereupon, and the length of coiled tubing to be carried. Repeated reeling and unreeling of coiled tubing on a reel decreases the life of the coiled tubing due at least partly to fatigue through bending stresses . Typically the injector is supported by the lifting device and the gooseneck includes a hydraulically powered boom or crane located at the rear of the coiled tubing trailer over the well. The hydraulically powered injector has drive chains with tubing grippers . The drive chains are hydraulically pressed against the tubing to grip the tubing and hydraulically driven sprockets drive the chains to run the tubing into or out of the well . The hydraulic power pack includes one or more engines driving one or more hydraulic pumps to power the reel, the crane, the injector, and other equipment. Other types of power equipment are also used. A typical gooseneck has a curved guide member that receives tubing extending from the reel , uncoils the tubing from the reel, and guides the tubing between the drive chains of the injector. A plurality of rollers on the gooseneck support the tubing while the tubing is being guided by the gooseneck into the injector. Small radius bends found in certain goosenecks result in stress on the tubing . - 3 - In certain wellbore operations a relatively long tool, tools, or wellbore apparatuses must be connected to the end of the coiled tubing. Such an assembly is generally much stiffer than the coiled tubing and the positioning of such an assembly over a wellhead can result in stress on the coiled tubing which is greater than the typical bending and plastic deformation of the tubing during its passage through the gooseneck. Such stress may cause fatigue failure of the tubing. According to the present invention, there is provided an apparatus for connecting coiled tubing to a member, said apparatus comprising a first connecting means for connection to coiled tubing, a second connecting means for connection to a member characterised in that said apparatus allows movement therebetween. The movement may be lateral and displace the longitudinal axis of one of said connecting means from the other. Other features of the invention are set out in the depending claims . - 4 - For a better understanding of the present invention, reference will now be made, by way of example, to the accompanying drawings , in which : Figure 1A is a side view, partly in cross-section, of an apparatus in accordance with the present invention, shown at a first stage of operation; Figure IB is a view taken along line IB-IB of Figure 1A; Figure 1C is a view taken along line 1C-1C of Figure 1A; Figure ID is a view taken along line ID-ID of Figure 1A; Figure IE is a side view of the apparatus of Figure 1A in cross-section of the connector of Figure 1A, shown at a second stage of operation; Figure IF is an enlarged view of part of the connector of Figure 1A; and Figure 2 is a schematic view of a system in accordance with the present invention incorporating an apparatus of the present invention. Referring to the Figures 1A to IF of the drawings, there is shown an apparatus in accordance with the present invention, generally identified by reference numeral 10. The apparatus 10 comprises an inner member 12 having a top threaded end 14 to which is threadedly connected a top sub 16. The inner member 12 has a fluid flow bore 18 therethrough from top to bottom and the top sub 16 has a fluid flow bore 22 therethrough from top to bottom. In use, coiled tubing (not shown) is located in fluid flow bore 18. The end of the coiled tubing (not shown) abuts a shoulder at a lower end 34 of the inner member 12. The seals (not shown) in inner member 12 seals the interface between the inner member 12 and the coiled tubing (not shown) . - 5 - O-ring seals (not shown) may be placed in corresponding inner grooves 26 of the inner member 12. An upper end 28 of the inner member 12 is movable longitudinally by relative rotation between the inner member 12 and the top sub 16 to contact and force upwardly a ratchet-toothed gripping apparatus 30. The ratchet-toothed gripping apparatus 30 is fast at the top end to a lug which is fast with the top sub 16. The ratchet-toothed gripping apparatus 30 depends from the lug. When the top sub 16 is tightened down on the inner member 12 (see Figure IE) the ratchet-toothed gripping apparatus moves inwardly. A set screw hole 32 permits a set to screw onto the tubing to hold the tubing. A housing 20 is threadedly connected to a lower end 34 of the inner member 12 which comprises an O-ring 36 which seals therebetween. A lower lip 38 of the housing 20 is positioned beneath a shoulder 42 of a movable member 40 and, initially, the lower lip 38 supports the movable member 40. A set screw 79 releasably extends through a set screw hole 77 to hold the top sub to the inner member 12. This screw is removed prior to setting of the ratchet toothed gripping apparatus 30 (see e.g. Figure IE) and may be reapplied thereafter. Set screws 76 may be introduced through a series of holes 44 through the housing 20. One or more clutch recesses 46 are provided at the end of the housing 20 to receive drive lugs 68. A bore 48 extends through the housing 20. The movable member 40 has a fluid flow bore 52 therethrough from top to bottom in fluid communication with the bore 48 of the housing 20. Upper O-ring seals 54 seal the interface between the movable member 40 and the housing 20. A groove 56 around the movable member 40 receives an end of a set screw or screws extending through the holes 44. Wrench flats 58 are used to rotate - 6 - the movable member 40, e.g. to threadedly connect it to another item or to a lower connection 60 and its drive lugs 68 are movable into the clutch recesses 46 of the housing 20. The lower connection 60 has internal threads 62 for threadedly engaging external threads 64 of the movable member 40 and external threads 66 for threadedly engaging a wellbore tool, apparatus, device, system, assembly, etc. Wrench flats 78 facilitate engagement of a wrench for rotation of the lower connection 60. As shown in Figure IE, the housing 20 has been moved down around the movable member 40 and the drive lugs 68 of the lower connection 60 are lockingly positioned in the clutch recesses 46 of the housing 20. Rotation of coil tubing held in the gripping apparatus 30 top sub 16, inner member 12 and housing 20 rotates the movable member 40, lower connection 60 and any tool, etc. connected to the lower connection 60. Also, in this position the movable member 40 is no longer free to move away from the longitudinal axis of the apparatus 10 , since the lip 38 of the housing 20 abuts a top end 72 of the lower connector 60 and a side 74 of the movable member 40. Also abutment of the upper end of the movable member 40 against an inner surface of the housing 20 and engagement of the set screws 76 prevents such lateral movement of the movable member 40. Figure IF illustrates the mismatch between the movable member 40 and the housing 20. Space 83 between the lip 38 and the shoulder 42 and space 80 between the lip 38 and the outer surface of the movable member 40 permit the movable member 40 to be canted from the longitudinal axis 82 of the apparatus 10. The freedom of movement of the movable member 40, and hence of whatever is connected to the lower connection 60 , both up and down and to a canted position, reduces stress on the coiled - 7 - tubing held by the gripping apparatus 30. Figure 2 shows a coiled tubing system 100 according to the present invention which includes a mobile truck and power unit 102 with a coiled tubing reel 104 and coiled tubing 106, a guide arch or gooseneck 108, support 109, an injector head 110, a blow-out preventer 112, a wellhead or valve 114, a control line housing 116, a coiled tubing hanger 118, a tubing hanger 120, and a casing hanger 122. In a wellbore 124 a connector 130 (like the connector 10 described above or any connector disclosed herein according to the present invention) is connected to the coiled tubing at its top end and to a wellbore tool 126, etc. at its bottom end.

Claims: - 8 - CLAIMS 1. An apparatus for connecting coiled tubing to a member, said apparatus comprising a first connecting means (30) for connection to coiled tubing, a second connecting means (60) for connection to a member characterised in that said apparatus allows movement therebetween . 2. An apparatus as claimed in Claim 1 , wherein said movement is provided by a knuckle joint (40) . 3. An apparatus as claimed in Claim 2 , wherein said knuckle joint (40) comprises a shoulder (38) and a lip (42) wherein a loose fit is provided therebetween. 4. An apparatus as claimed in Claim 1 , 2 or 3 , wherein said first and second connecting means are moveable longitudinally with respect to each other. 5. An apparatus as claimed in any preceding claim wherein said first (30) and said second (60) connecting means are moveable from a first position in which said second connecting means rotationally moveable with respect to said first connecting means, to a second position in which said means is rotationally fixed with said first connecting means . 6. An apparatus as claimed in Claim 5 , wherein said first (30) and said second (60) connectors comprise at least one of a lug (68) and a recess (46) , which interengage to obtain said second position . 7. An apparatus as claimed in any preceding claim wherein at least one of said first (30) and said second (60) connecting means is provided with wrench flats (58,78). 8. An apparatus as claimed in any preceding Claim, wherein said first connecting means (30) comprises a ratchet arm and a wedge, wherein after insertion of said coiled tubing, said wedge wedges said ratchet arm into engagement with said coiled tubing. - 9 - 9. An apparatus as claimed in Claim 8 , wherein said ratchet arm is fixed to an upper member (16) and said wedge is formed from the upper end of a body (12) wherein relative movement between said upper member (16) and said body (12) wedges said ratchet arm into engagement with said coiled tubing. 10. An apparatus as claimed in any preceding claim wherein said second connecting means is provided with a screw thread (66) . 11. An apparatus as claimed in any preceding claim, wherein said member is at least one of the following: drill pipe, casing, a tool, tool string or coiled tubing. 12. An apparatus as claimed any preceding, wherein said apparatus is provided with a flow path therethrough . 13. A system comprising the apparatus as claimed in any preceding claim, said system comprising coiled tubing (106) . 14. A system as claimed in claim 13, further comprising injection apparatus (100) connected to the coil tubing for moving the coil tubing into a wellbore. 15. A method for connecting coiled tubing to a member, using the apparatus as claimed in any of Claims 1 to 13, the method comprising the step of connecting coiled tubing and member to said apparatus whereupon lateral movement therebetween is facilitated.

Inventors: BEEMAN ROBERT STEPHEN, BREAUX STEPHEN P, BEEMAN, ROBERT, STEPHEN, BREAUX, STEPHEN, P.
Applicants: LUCAS BRIAN RONALD, WEATHERFORD LAMB, LUCAS, BRIAN, RONALD, WEATHERFORD/LAMB, INC.
Application year: 1999
Main classification: E21B17
IPC codes: E21B17