WO 2013/033848 PCT/CA2012/050624 1 "PULLING CLAMP FOR CONTINUOUS ROD OR COILED TUBING STRINGS" 2 3 CROSS-REFERENCE TO RELATED APPLICATIONS 4 This application is a regular application claiming priority of US 5 provisional application 61/532,348, filed September 8, 2011, the entirety of which is 6 incorporated herein by reference. 7 FIELD 8 Embodiments herein are related to apparatus used for temporarily 9 engaging a blunt end of a string of coiled or continuous rod or tubing, and more 10 particularly, to apparatus or clamps used for connecting between the string and 11 apparatus for lifting and lowering the string in and out of a wellbore, such as during 12 a servicing operation. 13 14 BACKGROUND 15 Downhole pumping operations in the oil and gas industry have used, 16 and many still use, a string of a plurality of sucker rods for operating downhole 17 pumps situate in wellbores accessing oil and gas formations. The sucker rods 18 themselves are typically fit with male and female threaded connections formed with 19 upset ends. For installation, retrieval and service operations, the threaded and 20 upset ends are also used to aid in handling the individual rods including engaging 21 the upset ends for supporting the combined weight of the string. 1 WO 2013/033848 PCT/CA2012/050624 1 The oil and gas industry has also become familiar with the use of 2 continuous or coiled rod and coiled tubing for operating wellbore pumps and 3 performing service operations. The continuous rod and coiled tubing are typical of 4 such continuous strings in that they are usually dispensed from a supply, run 5 through a wellhead into a wellbore to depth, suspended in the wellbore and cut off 6 above the wellhead. A single, continuous rod is conventionally often used to 7 replace a plurality of sucker rods for rotary drive of a progressive cavity pump or PC 8 pump. The continuous rod is rotatably supported at the wellhead, such as by a rod 9 clamp, and is rotatably connected and driven from a rotary drive at surface. Coiled 10 tubing is used for many different services, including for accessing the wellbore for 11 support of a downhole tool and communication of fluid between the tool and 12 surface. As with continuous rod, coiled tubing is typically supported at surface, 13 such as by a blowout preventer at the wellhead, and cut off thereabove for 14 connection to fluid devices. 15 The ability to cut off a continuous string at any point intermediate its 16 length is one advantage but also results in a string termination or blunt end which is 17 more cumbersome to later attach to for service operations, namely being absent a 18 designed upset or machined end for the gripping or mechanical attachment of 19 conventional service tools. 20 Particularly, in the case of continuous rod drive systems for downhole 21 tools, such as progressive cavity pumps, such as described in Applicant's co 22 pending applications, US published application 2011-0266005-Al, Canadian 2 WO 2013/033848 PCT/CA2012/050624 1 published application 2,738,500 and PCT published application 2 W02011/134085A1, a cut blunt end of the continuous rod string extends above the 3 drive head, but provides no convenient and secure point of attachment for the 4 attachment by lifting apparatus. During lifting, lowering and supporting of the 5 continuous rod string, such as for pulling the rod string and pump from the wellbore 6 or for pulling the pump's rotor from the pump's stator such as for cleaning the pump, 7 means are required to engage the cut end of the rod string. 8 It is known in the prior art to weld on a coupling for threaded 9 attachment or to apply a clamshell clamp for gripping about a blunt end of a 10 continuous string, such as where welding on-site may be dangerous. One example 11 is a Hunting Welltronic tool / tubing clamp as provided by Hunting Welltronic Ltd., of 12 Aberdeen, Scotland. As described, the Hunting Welltronic tool/tubing clamp is 13 a "device used for securing coiled tubing tools during deployment 14 operations. It can also be utilized to secure Coiled Tubing while being fed 15 off of the reel or being lifted up out of the hole or out of the well. The 16 tool/tubing Clamp comprises of two halves which contain slip segments to 17 suit a specific tool/tubing diameters. A tapered bowl ensures the slip grips 18 the tool/tubing in one direction and allows the tool/tubing to slip in the 19 other. The spacer plates retain the slips as well as prevent the clamp from 20 damaging the tool/tubing when the clamping bolt is engaged. The Tubing 21 Clamp can be supplied with a range of slips to suit various tool/tubing 22 diameters." 23 24 The prior art clamp is quite substantive is size and can interfere with 25 surface equipment including a pump drive head. Alteration of the blunt end for 26 convenience of connection or other purpose can have adverse ramifications for 27 surface equipment including drives and stuffing boxes. 3 WO 2013/033848 PCT/CA2012/050624 1 Clearly there is a need for reliable, safe means for engaging 2 connecting continuous or coiled rod and coiled tubing to tools, such as conventional 3 service tools including lifting and lowering apparatus, without the problems 4 associated with prior art clamps. 5 6 SUMMARY 7 A pulling clamp is provided for releaseable connection to a blunt, 8 uphole string end of a continuous string. The pulling clamp can form an upset for 9 engagement with lifting apparatus. Alternatively, the pulling clamp incorporates a 10 pulling connection for connection to lifting-specific components or a pony rod having 11 a conventional lifting end for engagement with the lifting apparatus. 12 In one embodiment, the pulling clamp comprises a main body having 13 a bore for releasably gripping the string end and provides a lower pulling end. The 14 main body itself forms an upset, the pulling end engagable by lifting apparatus. 15 In embodiments, the main body has a lower pulling end and an upper 16 pulled end, the main body having a clamp bore formed therethrough, the clamp 17 bore comprising a string-receiving opening at the pulling end for receiving the string 18 end, an actuating bore at the pulled end and a tapered bore therebetween. A taper 19 insert having a compressible gripping bore is provided and locatable in the tapered 20 bore. A top cap is engageable with the actuating bore, the top cap being axially 21 movable between passive and active positions to actuate the taper insert between a 22 first receiving position and second gripping position respectively, wherein in the first 4 WO 2013/033848 PCT/CA2012/050624 1 receiving position, the gripping bore receives the string end and is passively 2 uncompressed thereabout; and in the second gripping position, the top cap axially 3 engages the taper insert for driving the taper insert axially into the tapered bore for 4 radially compressing the taper insert about the string end for actively gripping the 5 string end therein. 6 In another embodiment, the actuating bore is threaded and the top 7 cap is threaded for threading axially into and out of the pulled end of the main body 8 between the passive and active positions. 9 10 BRIEF DESCRIPTION OF THE DRAWINGS 11 Figure 1A is a side view of an arrangement of a top drive for rotary 12 drive of a progressive cavity pump including a drive clamp according to the prior art 13 for suspending and rotatably coupling the continuous rod to the top drive and an 14 embodiment of a pulling clamp releasably connected to a cut end of the continuous 15 rod; 16 Figure 1B illustrates direct pulling of the pulling clamp by an elevator; 17 Figure 2A is a plan view of the pulling clamp according to Fig. 1A; 18 Figure 2B is a cross-sectional view of the pulling clamp along A-A of 19 Fig. 2A; 20 Figure 3 is a perspective view of the pulling clamp according to Fig. 21 1A; 5 WO 2013/033848 PCT/CA2012/050624 1 Figures 4A to 4C are perspective views of exploded components of 2 the pulling clamp as shown in Fig. 3, more particularly 3 Fig. 4A is a perspective view of a top cap; 4 Fig. 4B is a perspective view of a taper insert; 5 Fig. 4C is a perspective view of a main body of the pulling 6 clamp; and 7 Fig. 4D is a perspective view of a jam nut; 8 Figure 5A is a cross-sectional view of the pulling clamp according to 9 Fig. 3, illustrating the relationship between the components of Figs. 4A-4D when 10 assembled; 11 Figure 5B is a side view of the pulling clamp according to Fig. 5A; 12 Figure 6 is a partially sectioned perspective view, according to Fig 5A, 13 illustrating the positioning of the taper insert within the main body of the pulling 14 clamp, the taper insert shown in full engaged in the tapered bore; 15 Figure 7 is a perspective view according to Figs. 2B and 5A; 16 Figures 8A to 8D are detailed views of the top cap according to Fig. 17 4A and more particularly, 18 Fig. 8A is a side view illustrating internal threading of the top 19 cap in dotted lines; 20 Fig. 8B is a plan view according to Fig. 8A; 21 Fig. 8C is a side view according to Fig. 8A, the internal 22 threading in dotted lines being removed for clarity; and 6 WO 2013/033848 PCT/CA2012/050624 1 Fig. 8D is a plan view according to Fig. 8C; 2 Figures 9A to 9D are detailed views of the jam nut according to Fig. 3 4B and more particularly, 4 Fig. 9A is a side view illustrating internal threading of the jam 5 nut in dotted lines; 6 Fig. 9B is a plan view according to Fig. 9A; 7 Fig. 9C is a side view according to Fig. 9A, the internal 8 threading in dotted lines being removed for clarity; and 9 Fig. 9D is a plan view according to Fig. 9C; 10 Figures 10A to 10D are detailed views of the taper insert according to 11 Fig. 4C and more particularly, 12 Fig. 10A is a side view illustrating wickers within a bore of the 13 taper insert in dotted lines; 14 Fig. 1OB is a plan view according to Fig. 10A; 15 Fig. 10C is a side view according to Fig. 10A, the internal 16 threading in dotted lines being removed for clarity; and 17 Fig. 1OD is a plan view according to Fig. 1C; 18 Figures 11 A to 11 D are detailed views of the main body according to 19 Fig. 4D and more particularly, 20 Fig. 11 A is a side view illustrating internal threading of the main 21 body in dotted lines; 22 Fig. 11 B is a plan view according to Fig. 11 A; 7 WO 2013/033848 PCT/CA2012/050624 1 Fig. 11C is a side view according to Fig. 11A, the internal 2 threading in dotted lines being removed for clarity; and 3 Fig. 11 D is a plan view according to Fig. 11 C; 4 Figures 12A to 14C illustrate steps in a process of engaging 5 embodiments of the pulling clamp according to Fig. 3 with a cut end of continuous 6 rod, more particularly; 7 Fig. 12A is a side view of the pulling clamp, illustrating internal 8 threading and components in dotted lines, the cut end of the continuous rod 9 being inserted into the main body through the taper insert and bottoming out 10 at the top cap; 11 Fig. 12B is a side view according to Fig. 12A, the dotted lines 12 illustrating internal threading and components having been removed; 13 Fig. 13A is a side view of the pulling clamp according to Fig. 14 12A, the top cap being tightened to compress the taper insert about the cut 15 end; 16 Fig. 13B is a side view according to Fig. 13A, the dotted lines 17 illustrating internal threading and components having been removed; 18 Fig. 13C is a fanciful perspective view according to Fig. 13B, 19 wrenches shown engaging the main body to illustrate preventing rotation 20 thereof while the top cap is being rotated to tighten; 8 WO 2013/033848 PCT/CA2012/050624 1 Fig. 14A is a side view of the pulling clamp according to Fig. 2 13A, the jam nut being tightened against the main body to lock the top cap 3 against rotation; 4 Fig. 14B is a side view according to Fig. 14A, the dotted lines 5 illustrating internal threading and components having been removed; and 6 Fig. 14C is a fanciful perspective view according to Fig. 14B, a 7 wrench shown engaging the jam nut to indicate rotation of the jam nut; and 8 Figure 15 is a sectional view of a coiled tubing installation in which 9 embodiments of the pulling clamp are incorporated for servicing of the installation. 10 11 DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 12 Embodiments disclosed herein provide a multi-component pulling 13 clamp 10 for releasable connection to a cut or blunt end of a continuous rod or 14 tubing string without alteration of the blunt end, referred to herein as the string end. 15 Embodiments are particularly useful for continuous rod drive systems 16 for downhole tools, such as progressive cavity pumps as described in Applicant's 17 co-pending applications, US published application 2011-0266005-Al, Canadian 18 published application 2,738,500 and PCT published application 19 W02011/134085A1, incorporated herein by reference in their entirety. 20 Herein, embodiments of the pulling clamp 10 are often described in 21 the context of continuous rod having a solid, circular cross-section however other 9 WO 2013/033848 PCT/CA2012/050624 1 continuous string including coil tubing having tubular yet circular cross-sections are 2 contemplated. 3 In an embodiment, the pulling clamp is incorporated into a continuous 4 rod pumping system having a surface-accessible, string end and for enabling 5 servicing of the continuous string without substantial modification of the string end. 6 Such a rod-driven pumping system can comprise a drive positioned at surface, a 7 continuous rod driveably connected to the drive and extending downhole through a 8 bore of a production tubing to a pump, forming a production annulus therebetween, 9 and a coupling connecting between the continuous rod and the pump. In an 10 embodiment, the rod-driven pumping system is a rod-driven progressing cavity 11 pump having a stator and a rotor operatively engaged within the stator for rotation 12 therein. The drive comprises a drive head having a hollow drive shaft supported on 13 a wellhead at surface. The continuous rod is driveably connected through the hollow 14 drive shaft of the drive head. The continuous rod is connected at a downhole end 15 through a coupling to the rotor. 16 The continuous string extends through the drive and remains 17 unadulterated for servicing of the drive head thereover, including a stuffing box as 18 applicable. The string end is truncated to form a cylindrical end which is 19 unadulterated, having substantially the circular cross-section and cylindrical 20 dimensions of the remainder of the continuous string extending therebelow. 21 In another embodiment, a continuous string is provided for driving a 22 pump in a wellbore, the continuous string having an uphole end for drivingly 10 WO 2013/033848 PCT/CA2012/050624 1 connecting to a drive at surface and a downhole end for connection to the pump 2 such as through a coupling. Again, the uphole end is truncated to form a cylindrical 3 string end which is unadulterated, having substantially the cylindrical dimensions as 4 that of the remainder of the continuous rod extending therebelow. The string end is 5 accessible at surface for connection to an embodiment of a pulling clamp as set 6 forth herein. 7 Accordingly, an embodiment of the pulling clamp described herein can 8 be applied for temporarily connecting to and suspending the continuous string in 9 production tubing. The pulling clamp can be connected to structure for 10 implementing lifting or pulling of the continuous string. In an embodiment the pulling 11 clamp forms part of an elevator system for temporary and releasable connection to 12 a service rig, crane or other lifting apparatus. 13 Fig. 1A illustrates an arrangement of a top drive 1 for rotary drive of a 14 progressive cavity pump (PC pump). A continuous string 2 of continuous rod, such 15 as COROD@ (Trademark of Weatherford/Lamb, Inc.) extends through a wellhead 4 16 for connection to and driving the PC pump. The continuous string 2 has a generally 17 cylindrical cut end, referred to herein as a string end 6. A drive clamp 8, according 18 to the prior art, suspends the continuous string 2 in the wellbore and rotatably 19 couples the driven string 2 to the top drive 1. For manipulation of the string end 6, 20 such as for servicing the string 2, the well or the downhole tool or pump, an 21 embodiment of a pulling clamp 10 is releaseably connectable to the string end 6. 11 WO 2013/033848 PCT/CA2012/050624 1 The pulling clamp 10 is an easy to use, yet large lifting capacity device 2 having a narrow profile, sufficient to be fit and actuated in close quarters, such as 3 that shown in Fig. 1A where the wellhead centerline C is in close proximity to the 4 top drive 1. 5 The pulling clamp 10 can form an upset directly engageable with the 6 components of lifting apparatus, or can incorporate a pulling connection engageable 7 with the lifting apparatus. The pulling connection, such as an elevator 12 can be 8 connected directly to the pulling clamp 10 or can be connected thereto through an 9 intermediate apparatus 14, such as a length of pony or sucker rod. As shown, the 10 pony rod 14 is provided, at a first end 16, with the elevator 12 for connection to a 11 hook of the lifting apparatus. In the shown embodiment, the pony rod 14 is 12 threadably connected at a pulling connector 18 of the pulling clamp 10 for 13 connection to the string end 6. 14 As shown in Figs. 2A and 2B, an embodiment of the pulling clamp 10 15 engages the string end 6 for providing a releaseable connection between the 16 continuous string 2 and some lifting or pulling apparatus, such as a service rig. 17 In greater detail and having reference to Figs. 2B to 7 and Figs. 11 A to 18 11D, the pulling clamp 10 comprises a main body 20 having a string-receiving 19 opening or bore 22 at a pulling end 24 for receiving the string end 6 of the 20 continuous string 2 and an internal tapered bore section 26 thereabove. 21 As shown in Figs. 2B, 4B, 5A, 6, 7, and 10A to 10D, a taper insert 28 22 is provided for positioning within the tapered bore 26, the taper insert 28 having a 12 WO 2013/033848 PCT/CA2012/050624 1 gripping bore 30 for receiving the string end 6 and axially operable within the main 2 body's taper bore 26 for releasably and radially compressing the taper insert 28 for 3 gripping the string end 6 therein. The gripping bore 30 is radially compressible from 4 an open, receiving position, for axially receiving the string end 6 to a gripping 5 position. In the gripping position, the gripping bore 30 is compressible to a diameter 6 being smaller than a diameter of the string end 6 to be gripped. 7 A top cap 32 is provided and is axially movable into an actuating bore 8 34 at pulled end 36 of the main body 30, the actuating bore 34 being in 9 communication with the tapered bore 26 therebelow. 10 The top cap 32 is operable between two positions; movable between 11 passive and active positions to actuate the taper insert between a first receiving 12 position and second gripping position respectively. In the receiving position, the top 13 cap 42 is released sufficiently from the taper insert 28 to actuate the gripping bore 14 to an receiving position. In the gripping position, the top cap 32 is movable axially 15 into the actuating bore 34 for engaging the taper insert 28 and driving the taper 16 insert 28 axially into the tapered bore 26 of the main body 30. Tapered interface or 17 the taper insert 28 and tapered bore 30 cooperate to radially compress the taper 18 insert 28 and the gripping bore 30 to the gripping position for gripping the string end 19 6 therein. 20 In an embodiment, the top cap 32 is fit with an internal threaded 21 pulling bore 37 at a top free end 38 of the top cap 32 for engagement with the 22 pulling connection such as through the pony rod 14, as discussed above. 13 WO 2013/033848 PCT/CA2012/050624 1 Alternatively, as shown in Fig. 1B, the pulling clamp itself 10 forms a 2 releasable upset which can be releasably coupled to the blunt string end, an 3 elevator 12 engaging the pulling clamp directly such as about the pulling claim 10 or 4 directly below the main body 20. 5 In the gripping position, axial pulling load of the continuous string 2 is 6 transferred through the taper insert 28 and to the main body 20 by virtue of the 7 taper insert not being able to exit through the string-receiving opening. In the case 8 using a top cap connection, the load is transferred through the top cap 32 to the 9 lifting apparatus. 10 In greater detail, the taper insert 28 is actuated by axial movement of 11 the taper insert 28 along the taper bore 26. The taper insert 28 has a driven 12 shoulder 40 and the top cap 32 has a lower driving shoulder 42. 13 As shown, in this embodiment, axial movement is through threaded 14 movement of the top cap 32 in an internally threaded bore 34. The axial movement 15 moves the driving shoulder 42 axially along the main body 20. Tightening threaded 16 movement engages the top cap's driving shoulder 42 with the taper insert driven 17 shoulder 40 for actuating the taper insert 28 to move axially within the taper bore 18 26, radially compressing the gripping bore 30 about the string end 6. The structure 19 of the main body 20 is robust and resists the expansive forces thereon imposed by 20 the tapered interface between the taper insert 28 and the taper bore 26. In the 21 gripping position, the string-receiving bore or opening 22 has an effective diameter 14 WO 2013/033848 PCT/CA2012/050624 1 which is smaller than a combined diameter of the gripping taper insert 26 and string 2 end 6 to avoid pull through at string lifting weights. 3 The taper insert 28 may have an initial gripping bore diameter about 4 that of the string end 6. The gripping bore 30 may flex radially to receive the 5 diameter of the string end 6. Alternatively, the initial gripping bore diameter may be 6 slightly oversized to loosely to receive the diameter of the string end 6. 7 In an embodiment, the taper insert 28 is manufactured with an elastic 8 radial compressible range permitting the gripping bore 30 to open, as necessary, to 9 a diameter about that of the string end 6 in the released position and to radial 10 compress to the effective gripping diameter, in the gripping position. The pulling 11 clamp 10 is reuseable. One may replace the taper insert 28 each use or the taper 12 insert 28 is also reuseable. In an embodiment, the taper insert 28 has an elastic 13 compressible range to permit the radial compression and a radial release between 14 the first released position and second gripping position. 15 In embodiments, having reference to Figs. 2B, 3, 4D, 5A-7 and 9A-9D, 16 and where the top cap and main body are threadably coupled, locking means or 17 lock such as a jam nut 50 is provided to lock the top cap 32 into position, such as in 18 the gripping position to prevent premature release of the top cap 32 from driving 19 engagement with the taper insert 28. 20 The top cap 32 has head 52 at the free end 38 and a smaller diameter 21 externally threaded portion 54 which extends below for threading into the internally 22 threaded bore 34 of the pulled end 36 of the main body 20. The top cap external 15 WO 2013/033848 PCT/CA2012/050624 1 threaded portion 54 has a length greater than that of the main body's internally 2 threaded bore 34 sufficient to threadedly install the jam nut 50 therebetween. When 3 the top cap 32 is tightened to fully actuate the taper insert 28 to the gripping 4 position, there is sufficient axial clearance between the top cap 32 and a locking 5 shoulder 56 of the main body 20 to engage the jam nut 50, placing residual locking 6 forces between the top cap's external threaded portion 54 and the main body 7 locking shoulder 56. 8 As stated, the threaded portion of the threaded top cap has a length 9 greater than a depth of the actuating bore for forming an axial clearance 10 therebetween; and the jam nut is axially threadably actuable along the threaded 11 portion between an unlocked position wherein the jam nut is spaced above the main 12 body; and a locked position wherein the jam nut engages the main body. 13 As shown in Fig. 3, the main body, the head 52 of the top cap 32 and 14 the jam nut 50 are fit with respective flats 58 for opposing tool actuation. 15 In an embodiment, having reference to Fig. 4B and Figs. 10A to 10B, 16 the taper insert 28 has fluting 60. The fluting 60 enables elastic radial compression 17 without plastic deformation. The fluting 60 is axial to permit elastic bending at each 18 flute without a permanent, plastic deformation while the axially extending slip-like 19 portions retaining axial pulling design capability. Further, the taper insert 28 can be 20 discontinuous about its circumference at a slot 62 extending axially therealong. The 21 effective length or axial extent of the slot, open from a lower end, is compatible with 22 the axial extent of engagement with the tapered bore to permit radial compression. 16 WO 2013/033848 PCT/CA2012/050624 1 As shown the slot 62 can extend axially along the entirely of the taper insert 28. 2 The slot 62 enables a circumferential reduction of the gripping bore 30 upon 3 compression, the gripping bore 30 closing radially in on, and gripping, the string end 4 6. 5 In embodiments, the gripping bore 30 is fit with horizontally or 6 circumferentially extending wickers 64 for improving the gripping of the string end 6 7 therein in the gripping position. 8 As shown in Figs. 4D and 9C, the jam nut 50, has internal threads 58 9 sized for movement along the externally threaded portion 54 of the top cap 32 10 As shown in Figs. 5A and 5B, in the unactuated or open position, the 11 taper insert's gripping bore 30 has a diameter for receiving the string end 6. The 12 taper insert's driven shoulder 40 is standing axially proud inside the tapered bore 13 26, available for being driven axially downward into the tapered bore 26. The 14 driving shoulder 42 of the top cap 32 is shown just engaged with the driven shoulder 15 40, poised for actuation. The jam nut 50 is in the unlocked position. 16 Having reference to Fig. 6, the main body is shown partially cut-away 17 for illustrating the taper insert 28 residing within the tapered bore 26. The externally 18 threaded portion 54 of the top cap 32 is only partially engaged with the internal 19 threaded bore 34 of the main body 20, the taper insert 28 residing loosely within the 20 tapered bore 26. 21 22 17 WO 2013/033848 PCT/CA2012/050624 1 PROCEDURE: 2 In an embodiment, typical capacity of a pulling clamp for a 1-1/8" 3 continuous or coiled rod is about 70,000 pull weight, having a narrow profile of 4 about 2-7/8" and a height of just under 7". The top cap 32 is provided with a 5 standard box end being the internal threaded pulling bore 37 compatible with 6 conventional 1" sucker rod. 7 With reference to Fig. 1A, and Figs 12A through 14C, a typical 8 procedure is set forth for connecting a pulling clamp 10 according to embodiments 9 disclosed herein to a string end 6 for lifting and lowering a continuous rod string 2, 10 such as that extending through a top drive 1, such as for servicing the string 2 or a 11 wellbore tool 100 such as a pump connected thereto. Similar techniques and 12 adaptations are made for servicing a coiled tubing installation, an example of which 13 is set forth in Fig. 15, wherein a string end 6 of the coiled tubing string 2 extends 14 above the wellhead 4. 15 Good practice would suggest first cleaning and filing any sharp edges 16 from the string end 6 prior to engagement with the pulling clamp 10. Emery paper 17 can be used to clean any rust or protective shellac from the string end 6. 18 The string end 6 is measured and marked at about 2.5" from the end. 19 The jam nut 50 and top cap 32 of the pulling clamp 10 are unthreaded or backed off 20 sufficient to remove any force on the taper insert 28, ensuring the taper insert 28 is 21 in the receiving position. 18 WO 2013/033848 PCT/CA2012/050624 1 In an embodiment, a tapered interface of about 7' is provided over 2 about 2 inches axially. In this dimensional example, an axial actuation of about 0.06 3 inches is sufficient to effect gripping of the 1.125 inch cross-section. 4 5 CLAMPING THE TOOL: 6 Having reference to Figs. 12A and 12B, in a first step the pulling 7 clamp 10 is lowered onto the string end 6 by lowering the open string receiving bore 8 22 of the main body 20 over the string end 6, until the string end 6 is through the 9 taper insert 28, such as by bottoming out against the driving shoulder 42 or a recess 10 in the top cap 32. As a guideline, the 2.5" mark should be covered or hidden within 11 the main body 20. The top cap 32 is threaded into the main body 20 for engaging 12 the driving shoulder 42 with the taper insert driven shoulder 40. 13 In a second step, as shown in Figs. 13A, 13B and fancifully in 14 Fig. 13C to illustrate the use of two wrenches 70 applied to the wrench flats 58 of 15 the main body 20 and the top cap 32, at approximately 250 ft lbs torque, to thread 16 the top cap 32 into the main body 20. The taper insert 28 is driven downwardly and 17 the wickers 64 are driven or compressed radially inwardly to engage and grip the 18 string end 6. The circumference of the taper insert 28 reduces and the axial slot 62 19 closes as the taper insert 28 is driven downwardly into the tapered bore 26. As the 20 gripping bore 30 closes on the string end 6, the wrench torque rises to a set point 21 sufficient to achieve the pulling capacity. 19 WO 2013/033848 PCT/CA2012/050624 1 In a third step, as shown in Figs. 14A, 14B using a wrench 70 2 (Fig. 14C) applied to at least the wrench flats 58 of the jam nut 50 and where the 3 connection to the continuous string 2 resists rotation of the main body 20, the jam 4 nut 50 is threaded downwardly to engage the locking shoulder 56 of the main body 5 20. 6 Thereafter an integrity check of the installation is performed. 7 Depending on the particular wellhead 4, the continuous rod 2 in the wellhead 4 is 8 prepared for a pull test of the pulling clamp 10. If so provided, rod lock rams are 9 closed about the rod string 2 and tightened in the order of about 800 ft-lb. 10 As shown in Fig. 1B, a rod elevator 12 can be engaged to an 11 underside of the pulling clamp 10, the pulling claim acting as an upset of the prior 12 art sucker rods. As shown in Fig. 1A, where wellhead clearances are confined, a 13 first end of a pony rod 14, such as a 1" rod, can first be threaded into the connection 14 bore 37 of the top cap 32. A rod elevator 12 is engaged with a second upset end 16 15 of the pony rod 14. 16 In either engagement, lifting apparatus is connected to the elevator 12 17 and is actuated to carefully lift to raise the elevator 12 while watching a weight 18 indicator to confirm the pulling clamp 10 is engaged. At least 10,000 lbs is pulled to 19 confirm pulling clamp engagement. The elevator 12 is lowered but maintained in 20 tension with no weight on the weight indicator. The rod lock rams are then opened 21 after which the connected rod string 2 is ready to be raised or lowered. 22 20 WO 2013/033848 PCT/CA2012/050624 1 RELEASING THE TOOL: 2 The rod string 2 is supported in the wellhead 4, such as on the rod 3 lock rams or drive clamp 8. The jam nut 50 is backed off. The top cap 32 is 4 loosened. There is no need to remove the top cap 32 from the main body 20. The 5 top of the pulling clamp 10, such as on the top cap 32, is tapped to separate the 6 taper insert 28 from the main body 20 and separate the taper insert 28 from the 7 string end 6. The pulling clamp 10 can then be removed from the rod string 2.. 8 In the case where the taper insert 28 has wickers 64, the string end 6 9 may have scars such as ridging or scoring. To avoid damage to a stuffing box or 10 other drive head components, emery paper or a fine grade file is used to remove 11 any rod scars prior to drive head removal or installation. Generally, as a good 12 practice, one should keep the pulling clamp 10 free of crude oil, sand and debris, 13 and regularly remove the taper insert 28 and inspect for cracks or deformation. One 14 would visually inspect the pulling clamp 10 for damage before every use and 15 lubricate all threads with thread anti seize compound. 16 21