Patent Publication Number: US-11661800-B1

Title: Support apparatus for supporting down hole rotary tools

Description:
PRIORITY 
     This application is a continuation of U.S. patent application Ser. No. 16/385,895 filed 16 Apr. 2019 (now U.S. Pat. No. 10,633,931), which is a continuation of U.S. patent application Ser. No. 15/910,486 filed 2 Mar. 2018 (now U.S. Pat. No. 10,301,884), which is a continuation of U.S. patent application Ser. No. 15/482,364 filed 7 Apr. 2017 (now U.S. Pat. No. 9,938,778), which is a continuation of U.S. patent application Ser. No. 14/277,916 filed 15 May 2014 (now U.S. Pat. No. 9,650,841), which is a continuation of U.S. patent application Ser. No. 12/833,057 filed on 9 Jul. 2010 (now U.S. Pat. No. 8,793,960), which claims the benefit of priority to U.S. Provisional Application No. 61/277,529 filed 25 Sep. 2009, each of which is incorporated by reference. 
    
    
     FIELD OF THE INVENTION 
     This invention relates generally to an adjustable linear support structure traversable in two axes. More particularly it relates to a support structure positional adjacent a wellhead. The structure can be used for multiple purposes including supporting, extending and retracting rotating tools and extracting drill casing from wells during plug and abandon operations. 
     GENERAL BACKGROUND 
     The drilling process for oil and gas exploration typically requires the installation of production tubing that extends from the underground oil and gas reservoir to the well surface. This production tubing serves as a conduit for the recovery of the oil and gas from the reservoir. The production tubing is typically placed in a protective pipe liner called a tubular casing. The tubular casing, in descending diameters, extends in many cases to hundreds of feet and is often cement is placed within the annulus located between the tubular casing and the well bore to hold the tubular casing in place and to ensure a pressure-tight connection between the well surface and the oil and gas reservoir. 
     Usually the tubular casing remains within the well bore until it has been determined that no oil or gas reservoirs have been found or the reservoirs have been exhausted. In such cases, the well bore must be plugged and abandoned (P &amp; A) as required by law or convention. When a well bore is plugged and abandoned, the casing tubular is typically removed to a desired or prescribed depth and disposed of in a safe manner. 
     In other cases, an existing well bore is often utilized to allow the well to be drilled in a different direction. Often in such cases, the drill bit being used to advance the drilling cannot pass through the previously installed tubular casing due to an obstruction. If that occurs, it is necessary to remove the casing tubular to a desired depth before drilling operations can be restarted. 
     In most wells there are at least four tubular strings, beginning with the largest, upper and outer most conductor pipe, the surface casing, the intermediate tubular and finally the production casing. The removal of the tubular casing when required is often very difficult due to the tremendous weight of the tubular strings and, in some cases, the cement that has been placed around and between the various tubular strings. 
     The removal of the tubular casing from the well, such as when a well is to be plugged and abandoned, generally begins by first inspecting the well and insuring that the well is inactive and free of any residual gas and that the well is safe to allow for removal of the blowout preventers, well head, and other well equipment that is positioned above the tubing hangers. A safe work platform is then established around the wellhead and associated equipment. That work platform is then used to create a bridge plug within the production tubular at a prescribed depth by applying cement to seal or plug the well casing. The production tubular is then cut at a prescribed depth below the surface using chemical cut, jet cut, mechanical cut or other such rotating cutting tools. The cutting tool is supported on the surface and rotated by a rotary swivel. A lifting device is then attached to the inner most tubular by screwing into or spearing the tubular tubing hanger. 
     Such lifting devices may be the rig&#39;s crane if available and not in use by other drilling operations on the site. The production tubular is then lifted to a desired length, usually approximately forty feet, where slips are set to hold the string and tongs are used to uncouple the tubular joints. However, in many cases the drill casing tubular cannot be uncoupled in this manner. In the latter case, two diametrically opposing holes are cut in the casing and a bar is then inserted through the holes and the lifting device, such as a crane, is slaked off to allow the bar to rest on top of the well flange. The tubular is then flame cut just above the bar and the initial section of tubular is then removed. In some cases, where cement is present between the tubular strings, it becomes necessary to chip away the cement in order to cut the lifting bar holes. The crane then returns and is attached to the bar thus lifting the tubular string for another length and holes are again cut for a lifting bar. The process described above is then repeated for each tubular string until all the tubulars are removed. 
     Each incremental section of tubular usually requires operators to cut the casing, usually by torch, and manually drill two holes. The two holes are drilled from each side of the tubular in an attempt to keep them aligned with each other. It is essential that the holes be aligned with each other or large enough so that the bar or rod can be placed through the two holes. As discussed above, raising the tubular requires an extensive amount of force to overcome the resisting forces. Therefore, a stable platform is required. After the various increments of casing tubular are cut and pulled from the well bore, they are disposed of in a prescribed manner. Where holes drilled for the bars are individually and sequentially drilled in each incremental section of casing it is essential that proper tooling be used to maintain alignment. The operators usually drill one side at a time, a slow and tedious process, especially with heavy gauge pipe. In some cases up to two hours is required. The operator is required to drill a second hole that is diametrically opposite the first. In some cases the operator is fortunate enough to get the two holes lined up, but at other times the two holes did not line up and a bar could not be inserted through both holes in which case a torch is used to enlarge at least one of the holes so that the bar could be placed through both holes. 
     A dual drill system that drills holes from both sides simultaneously thereby insuring alignment may be used. Although the time required to drill the holes may be drastically reduced in such cases, a significant amount of time is still required to set up, and to clear, lubricate, and repair the drill bits. In addition, a torch is still often used to cut each section of the tubular being removed. Since a torch is used to separate the tubular into reasonable lengths, it has become more prevalent to simply cut the holes with a torch as well. In view of the process described above, a faster and more efficient method is needed to perform these tasks with greater certainty. 
     In more recent years the P &amp; A operation has included the use of a portable power swivel to assist in cutting casing down hole for removal. Such power swivels are generally portable hydraulic systems used on a well site having multiple well heads and where existing cranes are not always available for the P &amp; A operation. Therefore, a temporary derrick must be erected adjacent the wellhead to be removed and the P &amp; A operation carried out using the power swivel. Such derricks may or may not include a means for raising the well casing. In most cases a simple frame to support well casing cutting tools is sufficient to separate sections of the well casing. Such frames have evolved from a simple “A” frame structure to more complicated wellhead adapted frames having a vertical mast traversable in at least two planes. 
     However, in most cases the frames are fitted so as to include a power swivel and its cutting tools. However, in many cases such adaptation to an offshore wellhead is not necessary on well sites having multiple well heads. Such sites have very limited space available and therefore the size of the temporary derrick must be restricted. Therefore, a simple skid having traversable mast to support a plurality of tools is all that is needed. There a power swivel may be one of several tools that may be adapted to the mast, thereby making the skid and mast assembly much more universal. 
     While certain novel features of an embodiment of this invention are described below and pointed out in the drawings and annexed claims, the invention is not intended to be limited to the details specified herein, since a person of ordinary skill in the relevant art will understand that various omissions, modifications, substitutions and changes in the forms and details of the device illustrated and in its operation may be made without departing in any way from the scope of the present invention. No feature of the invention is critical or essential unless it is expressly stated as being “critical” or “essential.” 
     SUMMARY OF THE INVENTION 
     The instant invention relates to a portable horizontally oriented skid. The skid supports a vertically oriented mast assembly. The mast assembly is comprised of at least two column assemblies that may be extended or retracted vertically as desired. The position of the mast assembly on the skid may be translatable horizontally without the need for tracks or rollers. The skid is positionable adjacent a wellhead for the purpose of performing P &amp; A operations. 
     The skid may include a power swivel and other such hydraulic or mechanical tools. The skid when provided with such tools may be used for removing and plugging well casing strings, milling pipe strings, cement drilling, removing wellhead assemblies, or setting and pulling plugs from pipe strings. The skid includes fully enclosed hydraulic rams and may also include a pivotal swivel crane for supporting power tongs. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a further understanding of the nature and objects of the present invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings, in which, like parts are given like reference numerals, and wherein: 
         FIG.  1    is a frontal isometric elevation view of the frame assembly located above a deck access opening to a wellhead with the column assemblies of the mast assembly extended vertically. 
         FIG.  2    is a frontal isometric elevation view of the frame assembly with mast assembly traversed forward and with the column assemblies of the mast assembly vertically retracted. 
         FIG.  3    is a frontal isometric elevation view of the frame assembly with the mast assembly traversed rearward with the deck covers open and with the column assemblies of the mast assembly extended vertically. 
         FIG.  4    is a top view of the frame assembly with pivotal crane retracted and mast traversed forward. 
         FIG.  5    is a top view of the frame assembly with pivotal crane extended and mast traversed rearward. 
         FIG.  6    is a side elevated view of the frame assembly with the mast assembly traversed forward and with the column assembles extended vertically. 
         FIG.  7    is a side elevated view of the frame assembly with the mast assembly traversed rearward and with the column assembles retracted vertically. 
         FIG.  8    is a front elevation view of the frame assembly with the column assembles of the mast assembly extended vertically and pinned. 
         FIG.  9    is a cross section view of the frame assembly shown in  FIG.  8    with the column assembles of the mast assembly partially extended. 
         FIG.  10    is a partial cross sectional view taken along sight lines  10 - 10  as seen in  FIG.  8   . 
         FIG.  1    is a partial cross sectional view taken along sight lines  11 - 11  as seen in  FIG.  8   . 
         FIG.  12    is a partial exploded view of the extender head and bearing assembly. 
         FIG.  13    is a frontal elevation view of the frame assembly showing an elevator lifting assembly adaptation. 
         FIG.  14    is an alternate cross section view of the frame assembly shown in  FIG.  8    with the column assembles of the mast assembly partially extended by means of a mechanical screw-type actuator. 
     
    
    
     DESCRIPTION OF THE EMBODIMENT 
     As first seen in  FIG.  1   , the frame assembly  10  includes a horizontally oriented skid assembly  12 , a vertically oriented, extendable and retractable, mast assembly  14 , and a pivotal crane assembly  16  as support for various downhole tools such as optional hydraulic swivel assembly  11 . The mast assembly is slidably positionable on the skid frame. The skid assembly  12  is positioned on the well platform deck  13  adjacent to a platform wellhead opening  15 . 
     As seen in  FIG.  2   , the horizontally oriented skid assembly  12  includes a perimeter frame  18 , lifting eyes  20 , transverse cross members  22 , longitudinal support beams  24  that extend longitudinally along the length of the frame, longitudinal guides  26  that correspond to the support beams  24 , decking  28  and pivotal deck doors  30 . The guide  26  shown is comprised of overlapping stacked plates mounted to the support beams  24 . The top surface of each support beam  24  is positioned flush with the decking  28 . 
     The mast assembly  14  is comprised of a substantially U-shaped column base plate  47  that supports at least two vertically oriented, extendable and retractable, tubular column assemblies  49  which are capped by a split-bearing assembly  80 . The column assemblies  49  are tied together by a horizontal cross member  50 . The column base plate  47  is in turn supported upon longitudinal mast support beams  48 . Guide plates  26  slidable retain the mast support beams  48  directly upon the support beams  24  of the skid assembly  12 . As seen in  FIGS.  2  and  3   , the vertical assemblies  49  define a generally vertical plane and the vertical assemblies are vertically extendable and retractable along the vertical plane. 
     As seen in  FIG.  3   , the mast assembly  14  is traversable in a forward and rearward direction (forward being towards the doors  30 ) by means of at least one actuator  32  having an extendible and retractable rod  32   a , shown in section in  FIG.  14   , that is located above and within the perimeter frame  18  between beams  24 . The actuator  32  is horizontally oriented and mounted between the skid assembly  12  and said mast assembly  14  whereby extension retraction of the rod  32   a  will move the mast support beams  48  of the mast assembly  14  along the top of the support beams  24  of the skid assembly  12 . The actuators  32  may be hydraulic, pneumatic, or mechanical actuators. Such actuators are thought to be well known. For instance, a horizontally oriented screw-type actuator may be utilized for actuators  32  to traverse the mast assembly in a forward and rearward direction. The deck doors  30  of the skid assembly  12  pivotally open to provide access to the wellhead opening  15 . The column assemblies  49  are comprised of a lower tubular column segment  41  configured to telescopically receive an upper tubular column segment  43 . 
     As also seen in  FIG.  4   , a top view of the frame assembly  10 , the mast assembly  14  is shown extended forwardly. Here the actuators  32  are extended forward to a position whereby the center line of the split-bearing assemblies  80  on the column assemblies  49  of the mast assembly  14  may be aligned with the wellhead center line  36 . The pivotal crane assembly  16  has a right angle pivot arm  38  for supporting a set of tongs (not shown) so as to be aligned with the wellhead centerline  36 . 
     As may be seen in  FIG.  5   , an alternative top view of the frame assembly to, the mast assembly  14  is shown fully retracted rearward. Here the actuators  32  are retracted rearward to move the mast assembly away from the wellhead centerline  36 . The column assembly  49  is arranged to allow plenty of room over the exposed doors  30  of the skid assembly  12  in order to maneuver pivot crane  16  and its pivot arm  38  into position in alignment with the wellhead centerline  36 . This arrangement is beneficial in cases where tubing is uncoupled using tongs. When casing is being removed, using bars penetrating the casing (previously discussed but not shown); such bars may be supported by the doors or the top of beams  24 . 
     As seen in  FIG.  6   , the column assemblies  49  of the mast assembly  14  may be extended by pulling the upper tubular column segment  43  from within the lower tubular column segment  41 . The upper tubular column segment  43  may then be pinned in position on the lower tubular column segment  41  at a desired position between the fully retracted position seen in  FIG.  7    and the fully extended position seen in  FIG.  6   . The upper tubular column segment  43  and the lower tubular column segment  41  of each column assembly  49  are configured to fully enclose a mast extension and retraction actuator  52 . The actuators  52  may be hydraulic, pneumatic, or mechanical actuators. The column assemblies  49  of the mast assembly  14  may be configured vertically, by means of the actuators  52 , from a fully retracted position to a fully extended position, as shown in  FIG.  8   , or any selected point in between, Stiff legs  40  having a plurality of spaced apart selective holes  42  mounted on the outside of each upper column segment  41  and positioned with respect to a stiff leg support bracket  45  mounted on each lower column segment  43 . Each support bracket  45  has a hole  46  configured to correspond with a selected hole  42  on stiff legs  40 . Holes  42  and  45  are configured to receive pin  44  to retain each upper column segment  43  and the lower column segment  41  of the column assemblies  49  in a desired configuration. The combination of the pins  44  and stiff legs  40  and support bracket  45  allow stress on the upper tubular column segments  43  of the column assemblies  49  to be transferred via pins  44  to the lower tubular column segments  41  of column assemblies  49 . 
       FIG.  9   , a cross section view of the frame assembly shown in  FIG.  8   , further shows the configuration of the mast assembly  14  and its position with respect to the skid assembly  12 . The vertical column assemblies  49  of the mast assembly  14  are tied together by horizontal cross member  50 . The horizontal cross member  50  is offset rearwardly, forming a “U” shape, to allow additional clearance on all sides of the vertical centerline of the mast assembly  14 . Each vertical column assembly  49  is comprised of the lower tubular column segment  41  configured to telescopically receive the upper tubular column segment  43 . Each lower tubular column segment  41  serves to house a vertically oriented internal actuator  52 . As seen in  FIGS.  2  and  3   , cross member  50  has a generally U-shaped opening when viewed from above. As seen in  FIGS.  2  and  7   , for example, cross member  50  that connects vertical assemblies  49  is not part of a larger vertical assemblies support frame and is adjacent the top of the vertical assemblies  49  when the vertical assemblies  49  are retracted. 
     The actuators  52  are rigidly mounted at one end by a flange  54  to a flanged spool member  56  attached to the column base plate  47  at a position over longitudinal mast support beams  48 . It is thought that I-beams or wide flange (W) beams will be utilized for the mast support beams  48 . The telescopically extending rod end  53  of each actuator  52  is positioned with and pivotally mounted to the upper tubular column segment  43  by rod end assembly  58 . Longitudinal mast support beams  48  are positioned upon the skid support beams  24 . A flange of each mast support beam  48  is slidably retained and guided along the support beams  24  of the skid assembly  12  by longitudinally extending guides  26 . The guide  26  is mounted to the support beams  24 . The guide  26  shown is comprised of a plate stack comprised of a bottom plate  27  and an overlapping top plate  29 . The top plate  29  of the guide  26  extends over a flange of each mast support beam  48 . This allows the mast assembly  14  to be slidable moved forward and rearward by means of sliding the mast support beams  48  along the top of support beams  24  of the skid assembly  12  by action of the actuators  32 . 
       FIG.  14    shows an alternate embodiment of the frame assembly shown in  FIG.  8    and  FIG.  9   . Here each vertical column assembly  49  is comprised of a mechanical screw-type actuator  52 ′ having threaded actuator rod  53 ′ that serves to telescopically extend each upper tubular column  43  from each lower tubular column segment  41 . 
     Returning now to  FIG.  7   , we see that each vertical lower tubular column segment  41  of the column assemblies  49  includes diagonal bracing members  62 . The bracing members  62  are have flanges  64  for attachment of the bracing members  62  to base member assembly  66 . A plurality of “U” shaped bars  68 , provide steps along one side of at least one diagonal bracing member  62 . 
     Looking now at  FIG.  10   , the actuator  52  is shown fully rigidly suspended within the lower tubular column segment  41 . It can also be seen that upper tubular column segment  43  is telescopically guided within column segment  41  by wear strips  70 . As seen in  FIG.  11   , the rod end assembly  58  includes an actuator rod nut  72  that is made pivotal via pin  74 . Rod end assembly  58  also includes a mounting head  76  attached to upper tubular column segment  43  (not shown) and further supports rod nut  72  via plunger  78 . A split-bearing assembly  80  is mounted on the mounting head  76  on each vertical column assembly  49 . A more detailed exploded view of the assembly is shown in  FIG.  12   . 
     An operational view of the assembly  10  is shown in  FIG.  13   , utilizing pivotal elevator assembly  90  supported by a split-bearing assembly  80 . Elevator assembly  90  includes a support member  92  having a shaft extending from each end for support by bearings  80 . The support member  92  has a hole therein for supporting an elevator  94 , the elevator  94  having slips or other gripping devices (not shown) for gripping and extracting casing  96  from a wellbore. Extension and retraction of the column assemblies  49  of the mast assembly  14  will lift the casing supported on the elevator. 
     Often it is necessary to mill the surface of a downhole pipe string such as a casing string. The assembly  1   o  may be situated over a pipe string and used to simulate the weight of a drill collar for such milling purposes. This can be accomplished by providing the column assemblies  49  of the mast assembly  14  with actuators  52  that can provide both an upward and a downward force on the pipe string. Actuators  52  capable of providing both an upward force and a downward force of at least 15 tons, when used with a power swivel as shown in  FIG.  1    with an attached milling assembly, would be sufficient for simulating the weight of a drill collar for milling purposes. 
     When used for milling purposes, the assembly  10  is fitted with a power swivel having an attached pipe milling assembly with associated reaming and cutting equipment. The assembly  10  is brought to a desired wellhead location and the mast assembly  14  of the assembly  10  is traversed forward and rearward as desired by means of actuator  32  to position the milling assembly over the centerline of the wellhead and the pipe string. The actuators  52  of the column assemblies  49  are then retracted to apply a downward force on said milling assembly for milling of the pipe string. 
     Because many varying and different embodiments may be made within the scope of the inventive concept herein taught, and because many modifications may be made in the embodiments herein detailed in accordance with the descriptive requirement of the law, it is to be understood that the details herein are to be interpreted as illustrative and not in any limiting sense.