Abstract:
A gooseneck for coiled tubing operations have a folding design to allow for a more compact design for storage and transport. The gooseneck may remain attached to the injector during transport, thereby decreasing the equipment required to move and set-up the coiled tubing equipment. The gooseneck includes a linkage mechanism for connecting a pair of support struts between the injector body and the tubing guide. The linkage allows the guide to follow a substantially parabolic path as it tracks the tubing from the reel to the injector.

Description:
BACKGROUND  
         [0001]    1. Field of the Invention  
           [0002]    The present invention relates generally to a gooseneck for use in coiled tubing operations. More specifically, the invention describes a pivoting gooseneck incorporating a linkage mechanism that allows for safer, more stable operation.  
           [0003]    2. Description of the Prior Art  
           [0004]    Coiled tubing operations typically involve at least three primary components. The coiled tubing itself is disposed on a reel and must, therefore, be dispensed onto and off of the reel during an operation. The tubing extends from the reel to an injector. The injector moves the tubing into and out of the wellbore. Between the injector and the reel is a tubing guide or gooseneck. The gooseneck is typically attached or affixed to the injector and guides and supports the coiled tubing from the reel into the injector. Typically, the tubing guide is attached to the injector at the point where the tubing enters. As the tubing wraps and unwraps on the reel, it moves from one side of the reel to the other (side to side). The gooseneck typically has a flared end that accommodates this side to side movement.  
           [0005]    In performing a coiled tubing job or operation, the components required for the job (i.e., at least the coiled tubing reel, gooseneck and injector) are transported separately to the wellsite, thereby adding the expense of additional personnel and equipment (e.g., additional trucks). Once on site, the gooseneck must be attached to the injector. This increases set-up time and expense.  
           [0006]    One of the drawbacks of the basic gooseneck is that the flared end restricts the side to side movement or motion that can be tolerated by the system. There is an existing modification of the basic gooseneck (known as a “pivoting gooseneck”) that swivels or rotates about the centerline of the injector to allow greater side to side movement of the coiled tubing. For ease of description, the gooseneck position wherein its sides are parallel to the sides of the reel (i.e., wherein the coiled tubing is substantially centered on the reel), will be called the mean position or the zero degree position. However, the major drawback of the pivoting gooseneck is that it has a maximum potential energy at the mean position (i.e., a point on the gooseneck structure traces a path of an inverted “U” or inverted parabola as the gooseneck moves from side to side). This puts the pivoting gooseneck in unstable equilibrium. This unstable equilibrium has the tendency to push the gooseneck to either side. In certain situations, this tendency may cause the gooseneck to fall off the ends or may cause uneven or irregular motion of the tubing and/or gooseneck.  
         SUMMARY OF THE INVENTION  
         [0007]    The gooseneck of the present invention overcomes the drawbacks of the prior art by having a linkage mechanism that results in a minimum potential energy at the mean position (i.e., a point on the gooseneck structure traces a substantially parabolic path as the gooseneck moves from side to side). This ensures that the gooseneck is in stable equilibrium during normal or standard operating parameters. This feature also provides the gooseneck with the tendency to return to a stable, centered position, relative to the injector and the tubing reel, as opposed to prior art devices which tended to “fall off” to the side. It should be understood that any suitable design may be used in conjunction with the present invention to allow the gooseneck to trace or maintain a substantially “upright U” path as it tracks the coiled tubing traveling onto or off of the reel.  
           [0008]    The linkage mechanism is a four bar type, which consists of two cylinders, wherein the cylinders are each connected, at one end, to one corner of a triangular plate. The third corner of the plate is connected to the gooseneck. The triangular plate is typically positioned such that the third corner (i.e., a point on the gooseneck structure) traces a path of an upright “U” as the gooseneck rotates or pivots about to accommodate movement of the tubing as it feeds onto or off of the reel. The rotation of the gooseneck about the center of the injector is typically facilitated by a suitable bearing or other connector on the injector. The triangular plate may slide between two mounting plates, which are also connected or attached to the gooseneck itself.  
           [0009]    Another useful feature of the present gooseneck is the incorporation of an overload protection system or mechanism. The system minimizes the possibility of catastrophic failure in the event the gooseneck is overloaded, thereby improving the Safety of the coiled tubing operation. The system typically includes relief valves mounted on the cylinders that transfer the load from the gooseneck to the injector (i.e., the cylinders that form a part of the linkage, as previously described). The relief valves include a pressure sensing device for determining the pressure exerted in each cylinder and may be set to blow or release at a certain pressure, thereby limiting the load on the gooseneck and allowing for energy dissipation in the event of overloading.  
           [0010]    The basic gooseneck described in the prior art is generally a one-piece structure that cannot be lowered for tool installation, storage or transportation. The gooseneck of the present invention overcomes this limitation by having a compact folding design that allows the gooseneck to be lowered for tool installation and occupy a decreased space for purposes of storage and transportation. This is achieved by retracting the main cylinders (which support the gooseneck on the injector). As the cylinders retract, the gooseneck pivots about the pin connection at the injector and the gooseneck height is lowered, thus allowing more height for tool installation. The gooseneck may also be formed from a plurality of sections, which may be hinged or otherwise attached to each other such that when the gooseneck is not in use, it may be folded to a decreased, compact size. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    [0011]FIG. 1 is a schematic of a pivoting gooseneck.  
         [0012]    [0012]FIG. 2 is a schematic of the linkage mechanism of the pivoting gooseneck.  
         [0013]    [0013]FIG. 3 is a schematic of the guide in a partially folded configuration.  
         [0014]    [0014]FIG. 4 is a schematic of the guide in a partially folded configuration.  
         [0015]    [0015]FIG. 5 shows the gooseneck in the fully folded or compact orientation. 
     
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    [0016]FIG. 2 shows a gooseneck  30  in accordance with the present invention The gooseneck  30  is shown attached or affixed to injector  32  with a mounting plate or base  34 . The mounting plate rotationally supports the curvilinear tubing rail or guide  36 . The guide may be attached or secured to the mounting plate using any suitable mechanism. Preferably, the mounting plate includes a turntable bearing that is provided with a pair of ears or tabs  38  which correspond to holes formed in the “injector” or lower end  40  of the guide  36 . Although any suitable fastening device may be used to connect or join the guide to the mounting plate, bolts  39  are preferred.  
         [0017]    A pair of struts or cylinders  44 ,  45  are disposed between the injector or injector housing  42  and the guide  36 . The injector housing preferably includes a pair of strut mounting brackets  46 ,  47  thereon for accepting the corresponding lower ends  48 ,  49  of the struts. The lower ends  48 ,  49  of the struts may be fastened or mounted using any suitable fastener and preferably include a bearing to provide for rotation of the struts as the tubing guide rotates to track the tubing during operation. As shown in FIGS. 1 and 2, the upper ends  50 ,  51  of the struts  44 ,  45  are each attached to a first and second corner  56 ,  57  of a linkage plate  52 , respectively. The linkage plate may be of any suitable design or configuration but is preferably substantially triangular in shape and is preferable formed from high strength steel. The upper ends of the cylinders are preferably each provided with a suitable connector for attached or mounting the ends  50 ,  51  to the plate  52 . In a preferred embodiment, the connector is a spherical bearing  54  that allows rotation of the upper cylinder end in three planes to accommodate movement of the guide during operation, set-up and storage/transportation. The plate is preferably oriented such that the upper struts ends are essentially parallel when the gooseneck is perpendicular to the coiled tubing reel. As shown in FIG. 1, the cylinders may diverge to a certain degree as they extend from the plate to the injector housing. Most preferably, the plate has a downward orientation such that the third corner  58 , that is the corner not attached to a strut end, is generally directed toward the injector when the gooseneck and linkage is fully extended. A linkage mounting apparatus  60  attaches or secures the linkage plate  52  to the tubing guide  36 . The mounting apparatus includes a first, upper portion  62  and a second lower portion  64 . The first portion  62  is secured to the upper side  66  of the linkage plate and extends to attach to the guide rail. The second portion  64  is attached to the lower side  68  of the linkage plate. The second portion of the mounting apparatus extends from the linkage plate  52  to fasten or attach to the guide rail, proximally (i.e., closer to the injector) of the attachment point of the first portion. Both the first and second portions of the mounting apparatus are preferably welded to the guide rail, but may be attached using any suitable mechanism or fastener. An aperture or hole  70  is disposed through the third corner  58  of the mounting plate. The hole  70  corresponds to apertures  72  formed in the first and second portions  62 ,  64  of the mounting apparatus. A suitable fastener is provided to secure the plate between the first and second portions of the mounting apparatus. Preferably, a bushing or bearing is provided in the hole  70  to allow rotation of the triangular plate.  
         [0018]    In operation, the triangular linkage allows side-to-side or pivoting movement of the tubing guide without changing the length of the struts. This, in turn, allows better tracking of the tubing by the guide, as the tubing feeds onto or off of the reel. In addition, the struts or cylinders may be expandable, thereby allowing height adjustment of the gooseneck or allowing a greater range of motion, as compared to fixed length cylinders. Any suitable mechanism may be used to adjust the length of the cylinders, such as hydraulic pressure, air pressure or a mechanical actuator.  
         [0019]    The cylinders may further incorporate or include an overload protection system. The system functions to reduce the likelihood of a failure of the gooseneck and/or the cylinders by providing a mechanism for releasing or reducing pressure in the cylinders if the pressure exceeds a certain limit. Preferably, the system includes a relief valve on each cylinder. The valve may be set to release or blow before a catastrophic, overload failure can occur. In one embodiment, the relief valves may be mechanically set to release at a certain pressure. In another embodiment, the system may further incorporate a monitoring system to monitor pressure in the cylinders and open and close the relief valves as required to maintain optimal pressure in the cylinders without allowing them to reach overload. The monitoring system may also be used by personnel operating the equipment to determine cylinder pressures and modify or adjust the parameters of the operation to account for dangerous or excessive load increases on the gooseneck. Although in certain cases, it may be necessary to completely dissipate pressure in the cylinders, other cases may require that only a relatively small amount of pressure be relieved or bled off. The monitoring system may be used to either partially open a relief valve to slowly decrease pressure and/or open a valve for a limited duration of time sufficient to decrease the pressure in the cylinder to a safer level. In the event of a dangerous overload situation, however, the valves may be fully opened to relieve all of the pressure in the cylinders.  
         [0020]    Another embodiment of the present invention is a folding design that allows the gooseneck to be stored and transported in an assembled state. In the folded or compact configuration, the gooseneck may be attached to the injector such that the gooseneck/injector combination may be transported as a single unit within typical transportation size limits.  
         [0021]    [0021]FIG. 1 shows the gooseneck in a fully extended, work-ready form. FIG. 4 shows the gooseneck in a partially folded or retracted position. The tubing rail  36  preferably includes a plurality of curvilinear sections or components  72 ,  74 ,  76 ,  78  which are attached or connected to allow the gooseneck to be folded or retracted from the fully extended position. Preferably, the sections are connected with hinges  80 ,  82 ,  84 . In one embodiment, and as shown in FIGS.  3 - 5 , the hinges permit section  72  to fold or swing back until it is adjacent to and parallel with section  74 . A cylinder or piston  86  may be used to actuate the folding of section  72 ; however, any suitable method or mechanism may be used to actuate the section. FIG. 3 shows a gooseneck having section  72  in a folded or compact position.  
         [0022]    Similarly, and as shown in FIG. 4, section  74  is hingedly connected or attached with hinge  82  to section  76 . An actuator is provided to move or fold the section  74  until it is substantially adjacent and parallel to section  76 . Preferably, the actuator is a cylinder or piston, such as that used to actuate section  72 . Typically, section  72  is folded against section  74  prior to section  74  being folded against section  76 . In a preferred embodiment, the triangular linkage  52  is attached or connected to section  76 .  
         [0023]    As shown, the hinges  80 ,  82  allow the substantially horizontal folding of sections  72  and  74 . FIG. 5 shows the gooseneck in a final, folded position or configuration, such that it could be easily and efficiently stored or transported. Section  76  is hingedly attached to section  78  with hinge  84 . The hinge  84  is preferably positioned such that section  76  folds in a substantially downward manner, on top of section  78 . To facilitate the folding operation of section  76 , section  78  may be pivoted at the mounting plate  34 . Depending on the particular configuration of the gooseneck and the transportation or storage requirements that must be met, section  76  may not be folded completely onto section  78 . Similarly, section  78  may not be folded completely onto the injector housing  42 .  
         [0024]    In a preferred embodiment, a gooseneck support mechanism  86  is disposed on the injector housing  42 . The support mechanism preferably accepts or supports tubing retainer  88  when section  78  is moved to a folded or compact position. The mechanism provides support for the gooseneck and prevents it from directly contacting the injector housing.  
         [0025]    In operation, the gooseneck is preferably folded or unfolded/deployed using a plurality of hydraulic cylinders or actuators. Although any suitable combination of folds may be used to compact the gooseneck, a preferred embodiment utilizes a side folding configuration for sections  72  and  74  and a transverse fold for section  76 . That is, sections  72  and  74  are folded so that they along an axis generally parallel to the gooseneck and section  76  is folded along an axis generally perpendicular to the gooseneck.  
         [0026]    The compact design of the present folding gooseneck allows it to be transported or stored in a substantially smaller space than previous gooseneck designs. In a preferred embodiment, the gooseneck may by stored or transported attached or connected to the injector. This decreases the amount of transport vehicles required for equipment and also decreases the time required for setup or breakdown of the equipment at the wellsite.  
         [0027]    While certain features and embodiments of the invention have been shown in detail herein, it should be recognized that the invention includes all modifications and enhancements within the scope of the accompanying claims.