Abstract:
A pipe pick-up and lay down apparatus for lifting and lowering materials between a support frame and a rig floor of a workover rig, includes a support frame, a lifting arm, a controller and a lifting assembly for lifting and lowering the lifting arm. The lifting arm may be disposed in a trench in the support frame table and is substantially the same length and width as the trench and when in a lowered position. The lifting assembly may optionally include a power supply, a plurality of cables, and is operated by the controller to raise and lower the lifting arm.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Patent Application Ser. No. 61/675,200, filed Jul. 24, 2012 and entitled “Pipe Pick-Up and Lay Down Apparatus,” the disclosure of which is herein incorporated by reference. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The present invention relates generally to pipe handling systems for handling tubular pipe and more particularly to a pipe pick-up and lay down system for workover rigs used in drilling, production and servicing operations for transferring pipe between a platform and a rig floor elevated above the platform. 
       BACKGROUND OF THE INVENTION 
       [0003]    During drilling, production, and servicing of oil and gas wells, certain materials such as drill pipe, casing, and production tubing often need to be transferred between a storage platform and a rig floor. For example, during the drilling process, a drill string, composed of several individual joints of drill pipe, must sometimes be pulled out of the well bore to replace a drill bit. This process consists of removing the drill string and transferring the individual joints of pipe back to a platform located below the rig floor. An elevator or crane is used to lower the drill string from the rig to the platform. The platform is also known as a “catwalk” and is typically adjacent to a pipe rack holding multiple joints of drill pipe. After the drill bit is replaced, the process must be repeated in reverse order by transferring the pipe from the platform back onto the rig floor so that the individual pipe joints can be reconnected and ran back into the well bore. The drill pipe and other materials are extremely heavy and cumbersome and the rig floor is often 20 to 30 feet above ground floor. Accordingly, some sort of device is required to assist in the transfer of such materials from the platform to the rig floor. Numerous devices have been previously proposed for transferring pipe and other materials to and from the rig floor. Such devices are generally complex in construction, configured for use with only specific drilling rigs, and not easily transported from one drilling rig to another. 
         [0004]    Similar to the drilling process, during the servicing of a well, several steps are required to replace production tubing or to provide maintenance or replace downhole equipment. Rigs used for servicing wells are often referred to as “workover” rigs. Workover rigs typically have a rig floor which can be positioned over a well and the well&#39;s surface equipment. Workover rigs also generally have a mast which supports elevators used to raise and lower production tubing and handle individual joints of pipe used in the well bore. The rig floor of a workover rig is often elevated as much as 6 to 15 feet above ground level. Typically, the practice with workover rigs has been to manually transfer the pipe between the rig floor and a pipe rack located to the side of the platform. Thus, to lift a joint of pipe to the rig floor, a joint of drill pipe is rolled from the pipe rack to the platform where a worker manually lifts one end of the pipe off of the platform to a height at which the elevator of the rig can be latched onto the end of the pipe. This process is then reversed for removing the joints of pipe from the rig floor back onto the platform. 
         [0005]    Because of the manual labor involved and the weight and cumbersome nature of the drill pipe and other materials being transferred, the practice of transferring drill pipe from the platform to the rig floor, or from the rig floor to the platform, is extremely dangerous and labor intensive. Therefore, there is a need for a simple operation for transferring pipe up between the rig elevators and the platform or down between the platform and the rig elevators. It is to these and other deficiencies in the prior art that the present invention is directed. 
       SUMMARY OF THE INVENTION 
       [0006]    In preferred embodiments, the present invention provides an apparatus for easily transferring pipe and other materials from a platform to a rig floor of a workover rig elevated above the platform. The apparatus includes a support frame, a lifting arm, a lifting assembly and a controller. The support frame includes a trench disposed in its table which is substantially the same length and shape as the lifting arm. When the lifting arm is in a lowered position, the lifting arm is on the same plane as the table of the support frame. 
         [0007]    The lifting arm may consist of a first member, a second member and a pivot point. The first member of the lifting arm includes a first end which may include a yoke and a roller. The lifting assembly may consist of a block and tackle system and include a plurality of sheaves, a cable and a power supply. 
         [0008]    In another preferred embodiment, the present invention may include a bumper stop so that when the pipe is slid toward an end of the support frame, the bumper stop operates to absorb the shock and weight of the joint of pipe and stop the joint of pipe from sliding too far. Additionally, the present invention may include a stairway with a handrail for access to the table of the support frame. A walkway may be connected to the table of the support frame and may include a handrail which may be folded down toward a side of the support frame. The support frame may also include a removable pipe ramp so that the joint of pipe may easily be rolled from the pipe rack onto the support frame. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]      FIG. 1  is a side view of a pipe pick-up and lay down apparatus having a lifting arm in a lowered position and positioned in front of a workover rig. 
           [0010]      FIG. 2  is a front view of the pipe pick-up and lay down apparatus of  FIG. 1  illustrating a trench in which the lifting arm is disposed when in a lowered position and showing the pipe pick-up and lay down apparatus positioned adjacent to a pipe rack. 
           [0011]      FIG. 3  is a side view of the pipe pick-up and lay down apparatus of  FIG. 1  shown with the lifting arm in a raised position and positioned in front of a workover rig. 
           [0012]      FIG. 4  is a front view of one end of the lifting arm showing a yoke and a roller. 
           [0013]      FIG. 5  is a top view of the bumper stop positioned on the table of the support frame. 
           [0014]      FIG. 6  is a side view of the pipe pick-up and lay down apparatus of  FIG. 1  next to a workover rig. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0015]    Referring to  FIG. 1 , and generally to  FIGS. 1-3 , shown therein is an embodiment of a pipe pick-up and lay down apparatus  10 . The pipe pick-up and lay down apparatus  10  includes a support frame  12 , a lifting arm  14 , a block and tackle system  16 , and a controller  18 . 
         [0016]    The support frame  12  has a first end  22 , a second end  24 , a first side  26 , a second side  28 , an table  30 , and a base  32 . The support frame  12  is constructed of a plurality of tubular members interconnected to one another in a suitable manner, such as by welding. The support frame  12  may also include a stairway  34  ( FIG. 1 ) with a stairway handrail  35  to provide a worker with easy accessibility to the table  30  of the support frame  12 . A walkway  36  is connected to the table  30  of the support frame  12  and may be positioned on either the first side  26  or the second side  28  of the support frame  12 . The walkway  36  may be folded down toward the first side  26  or the second side  28  of the support frame  12  when not in use. 
         [0017]    The controller  18  is positioned on the table  30  of the support frame  12 . Alternatively, the controller  18  is configured for remote operation. As further shown in  FIG. 2 , a handrail  20  is positioned on the walkway  36  and is removable to allow the support frame  12  to be positioned next to a pipe rack  38  and to allow a joint of pipe  40  to be rolled from the support frame  12  to the pipe rack  38  which may be positioned on either the first side  26  or the second side  28  of the support frame  12 . In a preferred embodiment, the pipe pick-up and lay down apparatus  10  can be raised or lowered relative to the position of the pipe rack  38  so that multiple layers of pipe may be stored on the pipe rack  38 . In a presently preferred embodiment, the support frame  12  can be raised or lowered using telescoping tubular members that are mechanically, hydraulically or pneumatically raised and lowered. 
         [0018]    A removable pipe ramp  42  may be attached to the first side  26  or the second side  28  of the support frame  12  in various positions to assist in rolling the joint of pipe  40  onto the pipe rack  38 . The pipe ramp  42  is configured to facilitate the movement of pipe from the pipe pick-up and lay down apparatus  10  to the pipe rack  38  or from the pipe rack  38  to the pipe pick-up and lay down apparatus  10  regardless of their relative vertical positions. 
         [0019]    Referring to  FIGS. 1-3 , the support frame  12  further includes a trench  44  disposed in the table  30  of the support frame  12 . The trench  44  has a first end  46  and a second end  48 . The trench  44  extends along the table  30  of the support frame  12  near the first end  22  of the support frame  12  and is configured to substantially correspond with the shape and size of the lifting arm  14 . 
         [0020]    As shown in  FIGS. 1 and 3 , the lifting arm  14  consists of a first member  50  and a second member  52 . The first member  50  is connected to the second member  52  at a pivot point  54 . The first member  50  is substantially perpendicular to the second member  52 . The lifting arm  14  is constructed of a plurality of tubular members interconnected to one another in a suitable manner, such as by welding. The pivot point  54  of the lifting arm  14  is secured to the table  30  of the support frame  12  at the first end  46  of the trench  44 . As further shown in  FIG. 1 , when the lifting arm  14  is in its lowered position, the first member  50  of the lifting arm  14  is fully disposed in the trench  44 , and is substantially level with the table  30  of the support frame  12 . 
         [0021]    Referring now to  FIG. 4 , shown is a first end  56  of the first member  50  of the lifting arm  14 , which consists of a yoke  58  and an optional roller  60 . As shown in  FIG. 3 , when the lifting arm  14  is in the raised position, the joint of pipe  40  is positioned in the yoke  58  of the first end  56  of the first member  50  of the lifting arm  14 . 
         [0022]    Now referring to  FIG. 5 , shown is a bumper stop  62  which is removable and adjustable and consists of a first side  64 , a plurality of springs  66  and a second side  68 . The second side  68  of the bumper stop  62  is positioned near the second end  22  of the support frame  12 . When a joint of pipe  40  is lowered to the table  30  of the support frame  12 , the joint of pipe  40  hits the first side  64  of the bumper stop  62 , which absorbs shock from the weight of the joint of pipe  40  via the plurality of springs  66 . The bumper stop  62  can be installed at different locations on the support frame  12  to accommodate different lengths of pipe  40 . 
         [0023]    Returning now to  FIGS. 1 and 3 , the block and tackle system  16  is positioned between the table  30  and the base  32  of the support frame  12 . The block and tackle system  16  has been removed from  FIG. 2  for clarity. The block and tackle system  16  consists of a plurality of sheaves  70  ( 70   a,    70   b,    70   c  and  70   d ), a cable  72  and a pneumatic cylinder  74 . Generally, the block and tackle system  16  is configured to controllably raise and lower the lifting arm  14 . 
         [0024]    The pneumatic cylinder  74  includes a rod  78  that extends and retracts in response to application of pressure to the pneumatic cylinder  74 . The pneumatic cylinder  74  is connected to an air supply  76 . In a preferred embodiment, the air supply  76  is connected to an external supply of pressurized air from the workover rig or other nearby equipment. The pneumatic cylinder  74  is connected to and controlled by the controller  18 . 
         [0025]    In a presently preferred embodiment, the cable  72  is rigidly fixed on both ends to the support frame  12  and is routed around each of the plurality of sheaves  70 . Sheave  70   a  is supported on the rod  78 , sheave  70   b  is positioned on the support frame  12  behind the pneumatic cylinder  74 , sheave  70   c  is positioned on the second member  52  on the lifting arm  14  and sheave  70   d  is positioned on the support frame  12  above sheave  70   c.  As the air pressure in the pneumatic cylinder  74  increases, the rod  78  and sheave  70   a  are extended, thereby increasing the distance between sheaves  70   a  and  70   b  and exerting tension on the cable  72 . As the cable  72  is tensioned, the sheave  70   c  and the second member  52  move in the direction of sheave  70   d,  thereby causing the lifting arm  14  to pivot and the first member  50  is raised. 
         [0026]    When the pressure in the pneumatic cylinder  74  is decreased, the weight carried by the lifting arm  14  causes the lifting arm  14  to pivot and increase the distance between sheave  70   c  and sheave  70   d.  As the lifting arm  14  retracts, the cable  72  pulls sheave  70   a  and rod  78  into a retracted position within the pneumatic cylinder  74 . Thus, the block and tackle system  16  functions to move the lifting arm  14  from a lowered position ( FIG. 1 ) to a raised position ( FIG. 3 ) via the cable  72  and the plurality of sheaves  70  by controllably extending and retracting the rod  78 . 
         [0027]    The use of multiple sheaves  70  increases the mechanical advantage of the pneumatic cylinder  74  and cable  72 . Although the use of a single-acting pneumatic cylinder has been described herein, the use of dual-acting pneumatic cylinder is also contemplated. The ability to forcefully retract the pneumatic cylinder  74  may be particularly useful in applications where the weight of the lifting arm is insufficient to efficiently force the depressurized pneumatic cylinder  74  into a retracted position. It will also be understood that although a pneumatic cylinder is presently preferred, the lifting arm  14  may be raised and lowered using other suitable mechanical or hydraulic devices. 
         [0028]    Turning to  FIG. 6 , shown therein is a depiction of the pipe pick-up and lay down apparatus  10  positioned near a workover rig  82 . The workover rig  82  includes a rig floor  84  elevated a distance above the table  30  of the support frame  12 . The workover rig  82  also includes an elevator  86  for lowering the joint of pipe  40  onto a pipe catch bar  88  which is connected to a lower portion  90  of the workover rig  82  and which is elevated slightly above the table  30  of the support frame  12 . 
         [0029]    To raise the joint of pipe  40  from the table  30  of the support frame  12  to the rig floor  84  of the workover rig  82 , the pipe pick-up and lay down apparatus  10  uses the block and tackle system  16  to raise the lifting arm  14  holding the joint of pipe  40  in the yoke  58  of the first end  56  of the first member  50  of the lifting arm  14 . In this way, the lifting arm  14  is configured to raise the joint of pipe  40  by supporting a middle portion of the joint of pipe  40  within the yoke  58 . Once the joint of pipe  40  is lifted by the lifting arm  14  a worker can move the joint of pipe  58  forward slightly via the roller  60  located on the first end  56  of the first member  50  of the lifting arm  14 , or manually without the roller  60 , so that the joint of pipe  40  is supported by the pipe catch bar  88 . Once the pipe  40  is supported by the pipe catch bar  88 , the lifting arm  14  can be retracted and the pipe  40  can be connected to the elevator  86  of the workover rig  82  and lifted to the rig floor  84 . 
         [0030]    To lower a joint of pipe  40  from the rig floor  84  of the workover rig  82  onto the table  30  of the support frame  12 , the elevator  86  of the workover rig  82  lowers the joint of pipe  40  and a worker walks the joint of pipe  40  toward the bumper stop  62  and the second end  24  of the support frame  12 . Next, the joint of pipe  40  is disconnected from the elevator  86  of the workover rig  82  and dropped slightly onto the pipe catch bar  88 . Next, the pipe pick-up and lay down apparatus  10  uses the block and tackle system  16  to raise the lifting arm  14  which lifts the joint of pipe  40  slightly via the yoke  58  of the first end  56  of the first member  50  of the lifting arm  14 . In this way, the lifting arm  14  is configured to raise the joint of pipe  40  by supporting a middle portion of the joint of pipe  40  within the yoke  58 . 
         [0031]    Once the joint of pipe  40  is lifted up off of the pipe catch bar  88 , a worker moves the joint of pipe  40  slightly towards the second end  24  of the support frame  12  via the roller  60  located on the first end  56  of the first member  50  of the lifting arm  14 , or manually without the roller  60 , so that when the lifting arm  14  is in a fully lowered position ( FIG. 1 ), the entire joint of pipe  40  will be located on top of the table  30  of the support frame  12 . The bumper stop  62  may be positioned on the table  30  of the support frame  12  towards the second end  24  of the support frame  12  to absorb the shock of the joint of pipe  40  when it is laid down on the table  30  of the support frame. A worker can then roll the joint of pipe  40  onto the pipe rack  38 . 
         [0032]    It is to be understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description, together with details of the structure and functions of various embodiments of the invention, this disclosure is illustrative only, and changes may be made in detail, especially in matters of structure and arrangement of parts within the principles of the present invention to the full extent indicated by the broad general meaning of the terms expressed herein and in the appended claims. It will be appreciated by those skilled in the art that the teachings of the present invention can be applied to other systems without departing from the scope and spirit of the present invention.