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[0001]     This invention claims the benefit of convention priority of Canadian Patent Application No. 2,549,664, filed Jun. 6, 2006, entitled Articulated Mast For A Coiled Tubing Rig, the disclosures of which are incorporated herein by reference.  
       FIELD OF THE INVENTION  
       [0002]     This invention relates to an articulated mast for use in injection of tubing in well drilling operations.  
       BACKGROUND OF THE INVENTION  
       [0003]     In well drilling and servicing operations utilizing the coiled tubing technique, rigs are usually constructed on a transport trailer which may carry both the reel of continuous tubing and the mast which supports the tubing during injection and withdrawal of the tubing from the well being formed or serviced. In this arrangement while the mast must be capable of supporting the injection unit over the well head, it must be constructed to be lowered to a transport position which allows the trailer to be drawn over not only various forms of terrain, but along public roadways which have, of course, various restrictions, including overhead and width clearances. It is also essential that the mast and the injection unit be capable of quick installation over the well head once on site with the minimum of labour and subsequently restored to a transport condition after the well operation is completed.  
       SUMMARY OF THE INVENTION  
       [0004]     It is an object of the present invention to provide a coiled tubing injection system which is equipped with a versatile mast system capable of compact storage on a transport trailer but one which can be conveniently and quickly moved between operating and travel modes by way of that trailer. It is particularly an object of the present invention to provide a mast which allows locating of the injector unit accurately over a well head in a quick and efficient manner.  
         [0005]     According to the present invention there is provided an articulated mast for use in locating a tubing injection unit over a well head, and wherein the mast includes a lower mast section pivotally connected at one end to a carrier unit, an upper mast section pivotally connected at one end to a second end of the lower mast section opposite to the one end, and an extendible mast section carried at an end of the upper mast section opposite the one end and having an outer end for supporting the injector tubing injection unit. A first actuator means is connected between the lower mast section and the carrier unit for raising the lower mast section from a lowered transport position disposed substantially horizontally on the deck to a more upright operating position. A second actuator means is connected between the lower mast section and the upper mast section for pivoting the upper mast section independently of the first actuator means from a transport position immediately overlying the lower mast section in the transport position to a raised operative position. A third actuator means operative independently of the first and second actuator means for moving the extendible mast section relative to the upper mast section from a retracted position to a position selectively projecting beyond the outer end of the upper mast section.  
         [0006]     According to another aspect of the invention there is provided an articulated mast supporting a tubing injector unit for use on a transport trailer of the type having a rear deck portion, the articulated mast including, a lower boom or mast section having, a first connection means connecting one end of the lower mast section to the rear deck portion for pivotal movement from a substantially horizontal position on the rear deck about a transverse axis to a raised substantially vertical position, and first actuator means for raising and lowering the lower mast section between the horizontal and raised positions. There is further provided an upper boom or mast section having a main body portion with a second connection means for connecting a first end of the upper mast section to a second end of the lower mast section for pivotal movement of the upper mast section about a transverse axis parallel to the transverse axis of the first connecting means. This achieves raising of the upper mast section from a first horizontal position atop the lower boom section in the horizontal position of the lower mast section to a raised slanted position having upward and rearward components. A second actuator means is provided for raising and lowering the upper mast section between the positions of the upper mast. The upper mast section includes an extendible portion at a second end thereof and connected to the main body portion of the upper mast section for telescopic movement relative thereto so as to provide positioning of the extendible portion between a retracted position and an extended position for thereby increasing total length of the upper mast when in the extended position. A third actuator means is provided for moving the extendible portion between the retracted and extended positions. Connection means is mounted on the extendible portion of the upper mast member for carving a tubing injection unit. 
     
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0007]      FIG. 1  is a side elevational view of a complete coiled tube injection system incorporating the articulated mast of the present invention in a transport mode;  
         [0008]      FIG. 2  is a plan view of the system of  FIG. 1 ;  
         [0009]      FIG. 3  is a rear view on an enlarged scale of the system of  FIG. 1 ;  
         [0010]      FIG. 4  is a side elevational view of the system of  FIG. 1  but showing the injector moved to a position to allow the maneuvering of the gooseneck of the injector to an operative position;  
         [0011]      FIG. 5  is a side elevational view showing the initial movement of the lower and upper sections of the mast of the present invention towards an operative position;  
         [0012]      FIG. 6  is a side elevation view showing the final positions of the lower and upper section of the mast relative to each other; and  
         [0013]      FIG. 7  is a side elevational view showing the final extension of the upper section of the mast for placement of the injector over the well head structure.  
         [0014]      FIG. 8  is a simplified rear view of the articulated mast in an extended position, but with the coiled tubing injector removed.  
         [0015]      FIG. 9  is a simplified side view for illustrating the positioning of the actuator for the extendible mast section.  
         [0016]      FIG. 10  is an enlarged side view illustrating the transverse pivot connection between the lower and upper mast section.  
         [0017]      FIG. 11  is an enlarged side view illustrating the pivot connection of a tubing injector unit to the upper end of the mast. 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0018]     As shown in  FIGS. 1 and 2 , the complete coiled tubing injector system incorporating the articulated mast  10  of the invention is constructed on a carrier unit shown here as a road transport trailer  11  for being pulled between drilling or servicing sites by way of a tractor (not shown) when connected to the trailer through a fifth wheel system.  
         [0019]     The transport trailer  11  provides a front deck portion  12  on which are mounted servicing components  12  which may include, for example, components for supplying pressurized hydraulic fluid, such as an electric motor and pump unit, a hydraulic cooler, and a hydraulic tank. The transport trailer  11  further provides a middle, dropped portion  29  in which is mounted the tubing storage reel  14 . The articulated mast  10  of the present invention is mounted on a rear deck portion  15  of the transport trailer.  
         [0020]     The articulated mast  10  of the present invention includes a first boom or lower mast section  16  connected at a first end to the rearmost part of the rear deck position  15  by way of a transverse pivot connection  17  to allow pivoting of the lower section from a position which is substantially horizontally disposed on the deck ( FIGS. 1 &amp; 4 ) to a more upright position as seen in FIGS.  5  to  7 . The lower mast section is provided with motor or actuator means  18  ( FIG. 5 ), which is shown in the form of an expandible hydraulic cylinder pivotally connected at one end to the rear deck position forward of the transverse pivot connection  17 , and at the other end to the lower section  16  of the mast section at a point closer to the opposite end or of the lower section  16 .  
         [0021]     The articulated mast  10  further includes a second boom or upper mast section  20  which is pivotally connected at a first end by a transverse pivot connection  21  to a second or upper end of the lower section  16  for pivotal movement about a transverse axis  21  parallel to the axis of pivotal connection  17 . The transverse pivot connection  21  has its axis offset relative to the center lines of the lower and upper sections  16 , 20  in order that, as will be described in more detail below, when the articulated mast is in its lower most position as seen in  FIGS. 1 and 4 , the two sections are juxtaposed and both substantially horizontal and parallel to each other, so as occupying the minimum of height for transport. On expansion of the hydraulic cylinder  18 , the lower boom section is pivoted in a clockwise direction about pivot connection  17  as viewed in  FIG. 5 . Mounted on the lower section  16  there is disposed second motor or actuator means which is again in the form of an expandible hydraulic cylinder, the piston rod of which is connected through a linkage  23  to the upper section  21 . This second cylinder is pivotally connected at a lower end to the lower section  16 , and at its piston end to the linkage  19  which is described in more detail below, so that an expansion of the actuator means  22  the upper section is pivoted upwardly and away from the lower section  16  as shown first in  FIG. 5 , and then to its operative position as shown in  FIG. 6 .  
         [0022]     It may be noted, particularly from  FIG. 10 , that the second end or upper end of the lower section  16  of the mast forms an offset portion  40  in which the transverse pivot connection  21  for the first or lower end of the upper section  20  is located. Further, it can be seen that the lower end of the upper section  20  forms an offset portion  41  in which the axis of the pivot connection  21  is disposed. The linkage  19  includes a pair of links  42 , 43 , both of which ( 42 ) are pivotally connected on a common axis to the end of the piston rod of the hydraulic cylinder forming the actuator  22 . Link  42  is pivotally connected at its other end to the upper end of the lower section  16  of the mast. The one end of the second link  43  is thus connected coaxially with the first link  42  to the end of the piston rod, but at its other end, the link  43  is pivotally connected to the lower end portion of the upper section  20  of the mast. With this linkage arrangement  19 , the upper section  20  of the mast can be pivoted from its folded position in which it can be brought into parallel or even contacting relation to the lower section  16 . However, the upper section  20 , on full expansion of the actuator means  22 , can be swung at least to a position in which it is aligned (180°) in relation to the lower mast portion. This allows a maximum amount of positioning of the mast when extended, but while in the folded condition permits the positioning of the upper section  20  when brought back to its folded condition to closely overlie the lower section  16 , thereby providing a minimum of height for travel.  
         [0023]     The second boom or upper mast section  20  includes a third mast portion in the form of an extendible portion  24  ( FIGS. 7 &amp; 8 ) which is contained within the member of the main body of the upper section  20 . This extendible portion  24  is in effect telescopically positioned relative to its main body of upper section  20 , and is actuated by a third actuator means  45  ( FIG. 8 ) in the form of an expandible hydraulic cylinder, which is within and connected to the main body of the upper section  20  with a piston rod  46  thereof being connected to the extendible portion  24 . Thus, on expansion of this third expandible cylinder actuator  45 , the extendible portion  24  is forced outward relative to the main body portion of the upper section  20  to effectively extend the length of upper section  20  of the mast  10 . The extendible portion  24  is shown in the most projected position in  FIGS. 7 &amp; 8 .  
         [0024]     A tube injector unit  25  is connected to the outer end of the extendible portion  24  in a manner to pivot about a transverse axis  37  parallel to the axis of the pivot connections  17  and  21 . The pivot action of the injector unit  25  relative to extendible portion  24  of the mast  10  is provided through a linkage  26 , which is connected between the extendible portion  24  and a framework of the injection unit  25 , and includes actuator means  27  in the form of an fourth expandible cylinder. On expansion of the actuator means  27 , the injector unit  25  is movable from a position in which the main central axis  47  of the injector unit is substantially parallel to the axis of the lower and upper sections ( 16 , 20 ) of the mast in the transport mode as shown in  FIG. 1 , eventually to a position wherein its main central axis  47  is essentially vertical as positioned over a well head structure  28  as shown in  FIGS. 7 &amp; 10 .  
         [0025]     The injector unit  25  is of a common form used in the industry, having the main injection drive portion  30  and a gooseneck  31  which directs the tubing  32  being drawn from the storage reel  14  through a smooth curve. As is more apparent in the enlargement shown in  FIG. 11  the linkage  26  is capable of accomplishing the swinging of the injection unit  25  from a horizontal transport position immediately above the upper section  20  and its contained extendible section  24  then retracted to the full vertical operational position (FIGS.  7  &amp;  8 } by way of a single actuator means  27  in the form of a double acting hydraulic cylinder. The linkage includes a first link  50  which is attached at an outer end to a pin  51  forming a common first transverse axis at the end of the piston rod  52  of the actuator means  27 . An opposite end of the link  50  is pivotally connected to the injector unit  25  by a pin  53  affixed to the injector unit. The injector unit  25  per se is pivotally connected to the outer end of the extendible section  24  by way of a shaft  54  forming the transverse pivot axis of the injector unit  25 . Carried by shaft  54  up an arm  55 , which is pivotally connected by a pin  56  to one end of link  57  in turn pivotally connected at its opposite end to pin  51 . It may be noted that the orientation of the central axis of the injector unit  25 , with the actuator  27  in a retracted position, is substantially parallel to the longitudinal axis of the store sections  16  and  20  of the mast  120  and thus providing a low profile and safe stored position of the injector unit  25  of the unit for transport.  
         [0026]     The gooseneck  31  is designed to be collapsed as the articulated mast is contracted to a transport mode so as to conveniently occupy a space provided between spaced side members forming the upper and lower sections  16 , 20  of the mast. As shown the gooseneck consists of three sections, which in the operative form are in position to form a smoothly formed track defining the path of travel of the tubing  32 . A main portion  33  of the gooseneck is affixed to the framework of the injection drive portion, and an intermediate portion  34  is hinged to an outer end of main portion  33 , the latter being provided with a double action hydraulic cylinder  35  which, when expanded, pushes the intermediate portion  34  to its operating position as shown in dashed lines in  FIG. 4 . An outer end portion  36  is pivotally connected to the free end of the intermediate portion, with a hinge providing a limited swing into a curvature forming position in order that it is free to swing from a relative straight continuation of the intermediate portion in storage, as shown in  FIG. 1  to its operative form as shown in FIGS.  5  to  7 , the swinging operation being depicted by the two positions illustrated in  FIG. 4 .  
         [0027]     Following through from the relative positions of the articulated mast as shown in  FIG. 1  and FIGS.  4  to  7 , it can be readily seen the manner in which the components of the articulated mast  10  accomplish the feature of providing a mast structure which is compact for storage yet readily converted into an operational mode. It can also be seen that in the transport mode of  FIG. 1 , the height of the mast and associated injector  30  is no greater than the height of the storage reel located in the dropped portion of the transport trailer.  
         [0028]     As indicated in  FIG. 4 , when the system is to be transformed into the operative condition, the motor means or cylinder  27  is first expanded to tilt the injector drive portion  30  somewhat towards its final working position, at which time the hydraulic cylinder  35  is expanded to push the intermediate portion  34  of the gooseneck  31  into its operative position. At this same time, the outer end portion  36  swings to its operative position where it remains because of the form of its hinge as long as the injector drive portion continues from the position shown in  FIG. 4  and until it reaches its final working position. The boom forming the lower section  16  is then moved towards its operative position by expanding of the hydraulic cylinder forming motor means  18  and activation of hydraulic cylinder form the motor means  22  is also commended to start the raising of the boom forming the upper section  20  as indicated in  FIG. 5 . As the hydraulic cylinder  22  reaches its normally full extension, the upper boom is brought to its approximate final position as shown in  FIG. 6 . The third expandible hydraulic cylinder (not shown) is activated to telescope the extendible portions  24  to its final position, while the fourth expandible hydraulic cylinder  27  properly positions the injection drive portion  30  of the injection unit vertically over the well head structure  30  ( FIG. 7 ).  
         [0029]     After the drilling operation is completed, the hydraulic cylinders are operating substantially in the reverse order to place the overall tubing injection system in condition for transport ( FIG. 1 ). It is believed apparent from the above that the system incorporating the articulated mast of the present invention is of a relatively simple design providing for economic manufacture and requiring very little work crew to put it in condition for operation or transport. The present invention is capable not only of a large reach in view of the nature and connection of the mast sections, but it also is capable of easily positioning the injector unit at a required height. It also has the desirable feature of allowing the operator to effectively and with little effort move the injector unit accurately over the well head, due to the variety of adjustments possible by the relationship of its parts and the provision of the multiple actuators.  
         [0030]     While a single embodiment of the invention has been described variations within the spirit of the present invention as defined in the accompanying claims will be obvious to those skilled in the art.

Summary:
An articulated mast for use in supporting a coiled tubing injector on a deck of a transport trailer and capable of accomplishing storage of the mast and the injector in a compact manner on the deck for transport on the one hand in conjunction with other equipment in drilling operations, and yet capable of ready deployment of the injector to an operative position above a well head on the other hand. The mast includes boom sections pivotally joined relative to each other for movement between a position in which the sections are folded one on top of the other on the deck to an extended position for holding the tube injector above the well head rear of the transport deck.