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FIELD OF THE INVENTION 
       [0001]    The present invention relates to a device and a system for lifting holding and lowering casing joints and assembled casing strings. 
       BACKGROUND 
       [0002]    In down-hole drilling and extraction processes, casing, also called tubulars or piping, is run down the wellbore for the purposes of drilling, performing operations or producing oil from the well. Casing is made up by connecting multiple threaded casing sections together and feeding them into the wellbore. Typically, casing sections have a tapered female thread at one end and a tapered male thread at the other end. The male end of a first casing section is threaded into the female end of a second casing section to makeup the casing string. Rotation of the first casing into the second casing is conducted until the tapered ends engage one another. 
         [0003]    A typical system making up casing strings includes an elevator assembly housing a related gripping assembly and connected directly or indirectly to a travelling block, a flush mount or top mount spider, each having its own dedicated gripping assembly, connected directly or indirectly at the rig floor. 
         [0004]    A typical procedure for making up casing strings involves picking up a new joint of casing to be made up by the elevator assembly. The elevator assembly is raised to raise the casing joint into position above a casing string to be made up, the casing string being gripped in place by a flush mount or top mount spider. The elevator assembly is then lowered so that the male thread of the casing joint is engaged with the female thread of the uppermost casing of the casing string. 
         [0005]    The threads between the new casing joint and the uppermost casing of the casing string are then made up. The elevator then grips the new casing joint and is picked up to transfer the weight of the newly made up connection from the flush mount or top mount spider, so that the spider can be released. The elevator assembly then lowers the newly made up connection to the rig floor, which is then gripped again by the spider. The elevator assembly is then lowered, transferring the load to the spider, then the elevator is released and is prepared to pick up the next casing joint to be made up. 
         [0006]    A reverse procedure is practiced for breaking out casing joints from a casing string. Elevators and spiders conduct a number of complex operations and are typically made up of numerous moving and working parts. These tools must be able to carry large loads while gripping the casing joint to be made up, and the casing string. It must be easily operated and rapidly maintainable during wellbore operations. 
         [0007]    A constant need and interest therefore exists in the art to develop improved casing handling tools. 
       SUMMARY 
       [0008]    A tubular handling tool is provided for use as an elevator, comprising one or more slips movably retained by an upper ring and a lower ring, wherein the one or more upper rings and the one or more lower rings provide constraint against radial expansion forces. 
         [0009]    A frame for a tubular handling tool is further provided for use as an elevator comprising an upper ring and a lower ring in a vertically spaced relationship to one another and each having a central opening for receiving a casing section; and one or more removable means for connecting the upper ring and the lower ring and attaching the frame to a top drive or travelling block. 
         [0010]    A tubular handling tool is further provided for use as a top mount spider comprising one or more slips movably retained by one or more upper rings and one or more lower rings, wherein the one or more upper rings and the one or more lower rings provide constraint against radial expansion forces. 
         [0011]    A tubular handling tool is further provided for use as a flush mount spider comprising one or more slips movably retained by one or more upper rings and one or more lower rings. 
         [0012]    A slip is further provided comprising a removable sliphead. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    The present invention will now be described in greater detail, with reference to the following drawings, in which: 
           [0014]      FIG. 1  is an isometric view of one example of the elevator of the present invention; 
           [0015]      FIG. 2  is a cross-sectional view of one example of the elevator of the present invention; 
           [0016]      FIG. 3  is a top plan view of one example of the elevator of the present invention; 
           [0017]      FIG. 4  is an isometric view of a clevis pin of a present invention; 
           [0018]      FIG. 5  is a cross-sectional elevation view of a clevis pin of the present invention; 
           [0019]      FIG. 6  is an isometric of one example of the top mount spider of the present invention; 
           [0020]      FIG. 7  is a cross-sectional view of one example of the top mount spider of the present invention; 
           [0021]      FIG. 8  is a top plan view of one example of the top mount spider of the present invention; 
           [0022]      FIG. 9  is an isometric view of one example of the flush mount spider of the present invention; 
           [0023]      FIG. 10  is a cross section view of one example of the flush mount spider of the present invention; 
           [0024]      FIG. 11  is a top plan view of one example of the flush mount spider of the present invention; 
           [0025]      FIG. 12  is a first isometric view of one example of a slip and a die carrier of the present invention; 
           [0026]      FIG. 13  is a second isometric view of one example of a slip and a die carrier of the present invention; 
           [0027]      FIG. 14  is an isometric view one example of a sliphead of the present invention. 
           [0028]      FIG. 15   a  is a first detailed view of a segment of the present modular gripping assembly, showing the actuator timing plate and slip head; 
           [0029]      FIG. 15   b  is a second cross sectional detailed view of a segment of the present modular gripping assembly, showing the actuator timing plate and slip head; and 
           [0030]      FIG. 16  is a perspective view of one embodiment of a typical operational setup using a number of tools of the present invention. 
       
    
    
     DESCRIPTION OF THE INVENTION 
       [0031]    The present invention relates to device and a system for supporting, raising and lowering casing strings. The present invention more specifically relates to an elevator, a top mount spider and a flush mount spider (FMS) and their related gripping assemblies. 
         [0032]    With reference to  FIGS. 1 ,  2  and  3 , the present elevator  2  comprises one or more upper rings  4  and one or more lower rings  6  having multiple slip frames  8  supported by the upper rings  4  and lower rings  6  and arranged around the elevator  2 . The upper rings  4  and lower rings  6  also preferably provide radial constraint to the components inside the elevator  2 , such that the elevator  2  can withstand the radially expanding forces typically seen due to the axial loads experience by the elevator when lifting and lowering the casing string. 
         [0033]    A slip  10  may be slidingly received into each of said slip frames  8 . An insert carrier  12  may then be attached to each of said slips  10 . An actuator timing plate  14  connects to a sliphead  16  at an upper end of each slip  10 , and further connects to one or more cylinders  15  that are raised or lowered to actuate setting and releasing of the elevator  2  on the casing sections. 
         [0034]    A lowermost of the present lower rings  6 , preferably serves two purposes. It bears the load of elevator  2  including the casing string weight and preferably also it acts as a stabbing bell  6 A, which partially guides and aligns the casing section into the elevator  2 . The present design avoids the need of including an additional set of stabbing bells that then must be separately mounted on the elevator  2 . A reducer may further be used in conjunction with the stabbing bell  6 A, to accommodate smaller diameter casing. 
         [0035]    Optionally, removable lifting ears can be connectable to the elevator  2  to connect indirectly with a travelling block. 
         [0036]    With reference to  FIGS. 4 and 5 , more preferably, the lifting ears of the elevator  2  are in the form of a clevis assembly with pins  22 . The clevis assembly  22  of the present invention are preferably non-integral to the elevator  2  and are preferably made from a plate or bar material. The clevis assembly  22  is removably attached to the elevator  2  by inserting a lower end of the clevis pin through the upper rings  4  and lower rings  6  and locking the lower end in place by a retaining means  24  preferably in the form of a retaining nut or any other suitable and well known means of securing the lower end of the clevis assembly  22  to the elevator  2 . Further preferably the lower end of the clevis assembly  22  is machined with a profile to accommodate a split load ring  26  between a lower face of the lower ring  6  and the retaining nut  24 . The split load ring  26  acts to absorb and distribute a portion of the load from the casing string, to lessen wear on the lower end of the clevis assembly  22 . 
         [0037]    An upper end of the clevis assembly  22  is preferably forked with a bail retainer pin  28  that can be locked onto the bails of a top drive or to a travelling block. 
         [0038]      FIGS. 6 ,  7  and  8  illustrate one embodiment of a top mount spider  18  of the present invention. It has a series of upper rings  104  and lower rings  106  that provide radial constraint to the components inside the top mount spider  18 , such that the top mount spider  18  can withstand the radially expanding forces typically seen during make up and break out operations. More preferably, the upper rings  104  and lower rings  106  each take the form of one or more split rings, rotatably connected at a first end by a hinge  162  and secured together at a second end to form full rings. 
         [0039]    Multiple slip frames  108  supported by the upper rings  104  and lower rings  106  and arranged around the top mount spider  18 . A slip  110  is slidingly received into each of said slip frames  108 , and an insert carrier  112  is supported on each of said slips  110 . An actuator timing plate  114  connects to a sliphead  116  at an upper end of each slip  110 , and further connects to one or more cylinders  115  to actuate setting and releasing of the top mount spider  18  on the casing string at the well floor. 
         [0040]    More preferably a lowermost ring of lower ring  106  is formed with one or more key slots  107  that align matching key slots  109  at a lower end of slip frames  108 . 
         [0041]    Preferably, a locking plate (not shown) slides through these key slots  107 ,  109  and holds the slip frame  108  to the lower rings  106 . 
         [0042]    With reference to  FIGS. 9 ,  10  and  11 , a flush mount spider  60  of the present invention is shown. The flushmount spider  60  has a singular upper ring  204  and a lower ring  206  having multiple slip frames  208  supported by the upper ring  204  and lower ring  206  and arranged around the flush mount spider  60 . A slip  210  is slidingly received into each of said slip frames  208 , and an insert carrier  212  is supported on each of said slips  210 . An actuator timing plate  214  connects to a sliphead  216  at an upper end of each slip  210 , and further connects to one or more cylinders  215  to actuate setting and releasing of the flush mount spider  60  on the casing string at the well floor. 
         [0043]    More preferably the lower ring  206  is formed with one or more key slots  207  that align matching key slots  209  at a lower end of slip frames  208 . Preferably, a locking plate (not shown) slides through these key slots  207 ,  209  and holds the slip frame  208  to the lower rings  206 . 
         [0044]    One or more support shoulders or lugs  20  extend radially from the upper ring  204 , to engage with a rotary table, such that the flush mount spider  60  can be seated into the rotary table (not shown). 
         [0045]    With reference to  FIGS. 12 and 13 , the slips  10 ,  110 ,  210  of the present invention are preferably slidingly received in the slip frames  8 ,  108 ,  208  and rotationally constrained by engagement of the side edges of the slips  10 , 110 , 210  with shoulders of the slip frames  8 , 108 , 208 . 
         [0046]    Guide means  32 , preferably in the form of a mating profiles formed on the side edges of the slip  10 , 110 , 210  and the slip frames  8 , 108 , 208 , guide the slips radially outwardly when raised and radially inwardly when lowered by actuation of the cylinders  15 , 115 , 215 . Most preferably, guide means  32  take the form of a tongue and groove system that comprises either a tongue formed on the side edges of the slip  10 ,  110 ,  210  and a groove formed on the shoulders of the slip frame  8 ,  108 ,  208  or vice versa 
         [0047]    The insert carrier  12 ,  112 ,  212  of the present invention provides a unique means of carrying one or more dies  30 ,  130 , 230  on the insert carrier  12 ,  112 ,  212 , which can in turn be easily removed from the slip  10 ,  110 ,  210  and replaced. This allows for rapid change out of the dies  30 ,  130 ,  230  should they be come worn or damaged, and eliminates the need for removing individual dies from a slip  10 ,  110 ,  210 . A slot and tab profile  34 ,  134 ,  234  on the slip  10 ,  110 ,  210  and die carrier  12 ,  112 ,  212  acts as a means to radially retain the insert carrier  12 ,  112 ,  212  within the slip  10 ,  110 ,  210 . 
         [0048]    The inner face of slips  8 , 108 , 208  of the present invention are most preferably formed with a vertical upper surface  38 ,  138 ,  238  and an inclined lower surface  40 ,  140 ,  240  on the inner face of the slip  10 ,  110 ,  210 . A shoulder  36 ,  136 ,  236  exists between the vertical upper surface  38 ,  138 ,  238  and the inclined lower surface  40 ,  140 ,  240 . The outer face of the insert carrier  12 ,  112 ,  212  of the present invention are most preferably formed with a vertical upper surface  50 ,  150 ,  250  and an inclined lower surface  52 ,  152 ,  252  of. A ledge  48 ,  148 ,  248  is formed at the intersection of the vertical upper surface  50 ,  150 ,  250  and the inclined lower surface  52 ,  152 ,  252 . 
         [0049]    Axial loads from the casing section or casing string are preferably transferred into the mating inclined lower surfaces  40 ,  140 ,  240  of slip  10 , 110 ,  210  and inclined lower surfaces  52 ,  152 ,  252  of the insert carrier  12 ,  112 ,  212 . These mating lower inclined surfaces serve to support a portion of the axial load of the casing section or string and transfer some of the load bearing burden away from a thinner toe end of the slip  10 ,  110 ,  210  to a thicker upper portion of the slip  10 ,  110 ,  210 . A portion of the axial load is also preferably carried in the shoulder  36 , 136 , 236  of the upper surface of the  38 , 138 , 238  of the slip. This advantageously transfers some load away from a somewhat thinner lower inclined surface  40 , 140 , 240  to the somewhat thicker upper surface  38 , 138 , 238 . 
         [0050]    A singular retaining means  46 , 146 , 246  serves to retain the dies  30  to the insert carrier. Most preferably the singular retaining means takes the form of a singular die and insert carrier retainer plate  46 ,  146 ,  246  that is screwed, bolted or otherwise suitably removably attached to a top surface of the insert carrier  12 ,  112 ,  212 . The retainer plate  46 ,  146 ,  246  can be easily removed for inspection or replacement of the die  30 ,  130 ,  230  or insert carrier  12 ,  112 ,  212  without the need for removing separate plates for the die carrier and for the die. 
         [0051]    With reference to  FIG. 14 , a sliphead  16 ,  116 ,  216  is preferably separately machined and bolted to the slip  10 ,  110 ,  210 . Unlike slip heads that are traditionally casted or welded to a slip, the present sliphead  16 ,  116 ,  216  can easily be disconnected to service the slip  10 ,  110 ,  210  or insert carrier  12 ,  112 ,  212 . 
         [0052]      FIGS. 15   a  and  15   b  show further details of a preferred embodiment of the present actuator timing plate  14 ,  114 ,  214  and sliphead  16 ,  116 ,  216 . Each sliphead  16 , 116 ,  216  is preferably machined separately to the slip  10 ,  110 ,  210  itself and removably affixed to an upper end of each slip  10 , 110 ,  210 . The sliphead  16 , 116 ,  216  preferably comprises one or more rollers or cam followers  42 ,  142 ,  242  or more preferably one or more pairs of rollers or cam followers  42 , 142 ,  242  in an axially spaced arrangement with one another. The cam followers  42 ,  142 , 242  are rollably received in one or more cam follower caps  44 , 144 ,  244  located around the actuator timing plate  14 ,  114 ,  214 . The actuator timing plate  14 ,  114 ,  214  is further connected to one or more cylinders (not shown) to actuate setting and releasing of the slips  10 ,  110 ,  210  on the casing sections or the casing string. To set the slips  10 ,  110 ,  210  on the casing sections or casing string, the cylinders push the actuator timing plate  14 ,  114 ,  214  down. This in turn leads the slips  10 ,  110 ,  210  to travel both downwardly and radially inwardly along slip frames  8 ,  108 ,  208 . Radial movement of the slips  10 ,  110 ,  210  is accommodated in the actuator timing plate  14 ,  114 ,  214  by corresponding radial movement of the cam followers  42 ,  142 ,  242  inside the cam follower caps  44 ,  144 ,  244 . 
         [0053]    In a typical operation, as illustrated in  FIG. 16 , the present elevator assembly  2  and other optional devices are attached directly or indirectly to a travelling block. The elevator  2  is then lowered to a position near the rig floor to permit single joint elevator  200  to pick up a new joint of casing that has been raised from a pipe rack adjacent to the rig. 
         [0054]    The elevator  2  is raised, coupled to the single joint elevator  200  by two of the four elevator support bars  3  to thereby pull the casing joint up and along the rig&#39;s v-door ramp until it is raised above the existing casing string, set in a flush mount spider  60  or a top mount spider  18 . 
         [0055]    The elevator  2  is lowered to allow the male thread of the casing joint to engage the female thread of the uppermost casing of the casing string. 
         [0056]    The threads are then made up between the new casing joint and the uppermost casing of the casing string, set in the flush mount spider  60  or top mount spider  18 . 
         [0057]    Once made up, the single joint elevator  200  is released and the slips  10  in elevator  2  are set. The weight of the entire casing string, previously supported by a flush mount spider  60  or top mount spider  18 , will now be transferred to the elevator  2 , once the flush mount spider  60  or top mount spider  18  has been opened. The newly connected casing and casing string is then lowered into the well bore until the uppermost casing of the casing string reaches the rig floor. The flush mount spider  60  or top mount spider  18  is then set on the new uppermost casing, thereby taking over the load of the entire casing string. Once the flushmount spider  60  or top mount spider  18  is set, the elevator assembly  2  can be released, allowing the single joint elevator  200  to prepare to pick-up a new joint of casing. 
         [0058]    In the foregoing specification, the inventions have been described with a specific embodiments thereof; however, it will be evident that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention.

Summary:
A tubular handling tool is taught for use as an elevator, comprising one or more slips movably retained by one or more upper and lower rings, wherein the upper and lower rings provide constraint against radial expansion forces. A frame is taught for an elevator comprising one or more upper and lower rings and one or more removable means for connecting the upper and lower rings and attaching the frame to a top drive. A tubular handling tool is taught for use as a top mount spider comprising one or more slips movably retained by one or more upper and lower rings, wherein the upper and lower rings provide constraint against radial expansion forces. A tubular handling tool is taught for use as a flush mount spider comprising one or more slips movably retained on an upper ring and a lower ring. A slip is taught comprising a movable sliphead.