Abstract:
Devices and method for engaging a casing member for manipulation. A hydraulic torque locking mechanism is incorporated into a casing manipulation assembly. The hydraulic torque locking mechanism includes a clutch mechanism that is actuated using surface pump pressure from tool circulation.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    1. Field of the Invention 
         [0002]    The invention relates generally to a torque locking mechanism used in conjunction with casing manipulation systems. 
         [0003]    2. Description of the Related Art 
         [0004]    A number of systems are employed wherein drilling or reaming operations are done using casing strings. In these systems, a drilling tool or reaming tool is mounted upon a casing string in order to drill a wellbore or to enlarge or smooth an existing wellbore. The casing string and mounted drilling/reaming tool is rotated by a rig top drive unit at the surface. 
         [0005]    At times, these drilling or reaming tools can become stuck or require repositioning or manipulation from surface. In order to do this, a casing manipulation tool must be interconnected between the top drive unit and the casing string when the casing string needs manipulation. The casing manipulation tool allows the casing to be secured such that it can be pulled on, set down on and rotated. Casing manipulation tools are described in U.S. Pat. Publ. No. US 201210111556 by Palmer et al. and U.S. Pat. Publ. 2012/0125632 by Blair et al. Both of these references are owned by the assignee of the present application and are herein incorporated by reference in their entirety. Typically, right-hand rotation provided by the top drive is used to set the slips of the casing manipulation tool to cause it to grip the casing string. 
       SUMMARY OF THE INVENTION 
       [0006]    The invention provides systems and methods for preventing inadvertent unsetting of a casing manipulation tool by left-hand rotation of a casing string or casing member. In a described embodiment, a casing manipulation assembly includes a central mandrel that is rotated by a top drive unit and a housing that radially surrounds the mandrel. When the mandrel is rotated by the top drive, the housing is moved axially with respect to the mandrel in order to set slips within the casing string or member. 
         [0007]    In a described embodiment, a hydraulic torque locking mechanism is incorporated into a casing manipulation assembly. The hydraulic torque locking mechanism includes a clutch mechanism that is actuated using surface pump pressure from tool circulation. The fluid pressure acts upon a piston that is moveable to selectively engage the clutch mechanism. Thus, the torque locking mechanism is moveable between an unengaged position and an engaged position. The torque locking mechanism selectively locks rotation of the housing with respect to the mandrel. 
         [0008]    In operation, the torque locking mechanism and casing manipulation tool are operably interconnected with a top drive device. The casing manipulation assembly is then run into the casing string and the torque locking mechanism shoulders on top of the casing string. The torque locking mechanism is run-in in the unengaged position. Thereafter, after applying set down weight of the torque locking mechanism to provide friction resistance, the top drive device provides right-hand rotation to cause the casing manipulation tool to become set within and grip the casing member. Next, the torque locking mechanism is moved from the unengaged position to the engaged position by pump pressure. When the torque locking mechanism is engaged, right-hand torque is now transmitted from the top drive to the casing string. Any left-hand rotation to the casing is prevented by the engagement of clutch teeth in the torque locking mechanism. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0009]    For a thorough understanding of the present invention, reference is made to the following detailed description of the preferred embodiments taken in conjunction with the accompanying drawings, wherein like reference numerals designate like or similar elements throughout the several figures of the drawings and wherein: 
           [0010]      FIG. 1  is a side, cross-sectional view of an exemplary wellbore containing a casing manipulation tool in accordance with the present invention. 
           [0011]      FIG. 2  is an external, isometric view of an exemplary torque locking mechanism constructed in accordance with the present invention in the run-in position. 
           [0012]      FIG. 3  is an enlarged external, isometric view of interior portions of he torque locking mechanism shown in  FIG. 2 . 
           [0013]      FIG. 4  is a side, cross-sectional view of the torque locking mechanism shown in  FIG. 2  with the mechanism also in a run-in position. 
           [0014]      FIG. 5  is an external, isometric view of the torque locking mechanism shown in  FIGS. 3-4 , now in an engaged position. 
           [0015]      FIG. 6  is a side, cross-sectional view of an exemplary casing manipulation assembly, now engaged with a casing member. 
       
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0016]      FIG. 1  depicts a rig  10  having a derrick  12  with a rig floor  14  at its lower end and having an opening  16  through which a wellbore  18  can be accessed. The wellbore  18  is shown to contain a portion of casing  20 . A work string  22  is shown suspended from a rotary top drive drilling unit  24  of a type known in the art which is used to rotate the work string  22 . A pipe handler assembly  26  is also suspended from the drilling unit  24  and is operable to suspend the work string  22 . Fluid can be introduced into the upper end of the work string  22  through a swivel  28  connected to the upper end of the top drive unit  24 . The swivel  28  and connected top drive unit  24  and pipe handler  26  are, in turn, suspended from a traveling block  30  which is suspended and moved upwardly and downwardly by a line  32  which is connected at its upper end to a crown block (not shown) and actuated by draw works  34 . 
         [0017]    Affixed to the lower end of the work string  22  is a casing manipulation assembly, generally indicated at  36 . The casing manipulation assembly  36  is shown in greater detail in  FIG. 2  and includes a casing manipulation tool  38  and a hydraulic torque locking mechanism  40 . The casing manipulation tool  38  features a packoff mandrel assembly  42  and a friction block assembly wherein friction blocks  44  as biased radially outwardly by springs  45  (see  FIG. 6 ). In addition, the casing manipulation tool  38  includes a slip assembly  46  which includes anchoring slips  48  that are moved radially outwardly to grip the interior of the casing  20 . Further details relating to the construction and operation of casing manipulation tools are found in U.S. Pat. Publ. No. US 2012/0111556 by Palmer et al. and U.S. Pat. Publ. 2012/0125632 by Blair et al. However, in general operation, the casing manipulation tool  38  is disposed into the casing  20  and then the top drive unit  24  will apply right-hand rotation to the casing manipulation tool  38  to cause the slips  48  o move radially outwardly into anchoring contact with the casing  20 . 
         [0018]      FIGS. 2-6  depict the exemplary hydraulic torque locking mechanism  40  constructed in accordance with the present invention. The torque locking mechanism  40  includes a central mandrel  50  having a central axial flowbore  52  defined along its length. A housing  54  circumferentially surrounds the central mandrel  50 . In the depicted embodiment, the housing  54  is made up of upper and lower housing portions  56 ,  58  that are secured together by connectors  60 . In  FIGS. 3 and 5 , the lower housing portion  58  has been removed to allow interior components to be seen. As shown in  FIG. 4 , clutch chamber  62  is defined within the lower housing portion  58 . A threaded interface  63  is formed between the housing  54  and the mandrel  50 . In a particular embodiment, the threaded interface  63  has left-handed threading, and right-hand rotation applied by the top drive unit  24  ( FIG. 1 ) will move the mandrel  50  axially with respect to the housing  54 , setting the slips  48 . 
         [0019]    The upper axial end of the central mandrel  50  may be provided with threaded portions, as are known in the art, to allow it to be affixed to a neighboring component. Within the housing  54 , the central mandrel  50  is made up of an enlarged diameter portion  64 , an intermediate diameter portion  66  and a reduced diameter portion  68 . 
         [0020]    An annular piston  70  ( FIG. 4 ) circumferentially surrounds the intermediate diameter and reduced diameter portions  66 ,  68  of the central mandrel  50 . An annular fluid chamber  72  is defined within the housing  54  above the piston  70 . Lateral fluid passages  74  extend from the central axial flowbore  52  to the annular piston chamber  72 . The piston  70  is slidably moveable upon the central mandrel  50 . Anti-rotation guide pins  74  are affixed to the piston  70  by screws  76 . 
         [0021]    A clutch assembly, generally shown at  78  is contained within the clutch chamber  62 . The clutch assembly  78  includes first and second complementary annular clutch pads  80 ,  82 . The clutch pads  80 ,  82  each present complementary teeth  84 . The first clutch pad  80  is affixed to the piston  70 . The second clutch pad  82  is affixed to a clutch ring  86 . The clutch ring  86  is secured to the mandrel  50  by threaded connection  88 . Anti-rotation pins  89  are used to prevent the threaded connection  88  from unthreading. The teeth  84  of the clutch pad  80  and those of the clutch pad  82  will interlock with each other, as depicted in  FIG. 5 , when the clutch pads  80 ,  82  are brought into contact with each other. The clutch assembly  78  can be moved between art unengaged position, depicted in  FIGS. 3-4 , and an engaged position, which is depicted in  FIG. 5 . 
         [0022]    A compression spring  90  is disposed between the piston  70  and the clutch ring  86  and biases the clutch assembly  78  toward the unengaged position. The guide pins  74  are disposed within guide pin recesses  92  that are formed within the surrounding housing  54 . The guide pins  74  can move axially within the recesses  92 . However, location of the pins  74  prevents the affixed piston  70  from rotation with respect to the housing  54 . 
         [0023]    The hydraulic torque locking mechanism  40  is moved from the unengaged position to the engaged position by flowing hydraulic fluid into the work string  22  and into the flowbore  52  of the mechanism  40 . Fluid will enter the annular piston chamber  72  via the lateral passages  74 . Fluid will urge the piston  70  axially downwardly to cause the clutch pads  80 ,  82  to be brought into engagement with each other. Spring  90  is compressed when this occurs. When fluid flow stops, the spring  90  urges the torque locking mechanism back to the unengaged position. 
         [0024]    In operation, the casing manipulation assembly  36  is used to secure the casing  20  and then allow rotation or axial movement to be applied to the casing  20 . The casing  20  is secured by at least partially inserting the casing manipulation tool  38  into the casing  20  and then securing it to the casing  20  by setting the slips  48 . As the casing manipulation tool  38  is inserted into the casing  20 , the friction blocks  44  create a friction mechanism that will grippingly engage the casing  20  (see  FIG. 6 ) as the blocks  44  are biased radially outwardly by the springs  45 . In addition, as depicted in  FIG. 6 , the lower housing portion  58  is placed in contact with the casing  20 . The slips  48  are then set as the work string  22  is rotated by the top drive unit  24 . The applied rotation is in the right-hand direction, and this rotation, via the threaded interface  63 , will move mandrel  50  upwardly, thereby setting the slips  48 . Once the slips  48  are set, the torque locking mechanism  40  is moved from the unengaged position to the engaged position in the manner described above. When engaged, the torque locking mechanism  40  ensures that torque is transmitted from the work string  22  to the casing  20 . When engaged, it also ensures that left-hand torque or backlash is not transmitted from the casing string  20  to the casing manipulation tool  38 . Such left-hand torque might occur as a result of counter-rotation of the casing. This could be caused by increased torque at a specified speed causing the revolutions to slow down, therefore storing energy into the casing string  20 . When the cause of the increase in torque suddenly diminishes, the stored energy in the casing string  20  will “outrun” the desired rotation speed. At that point, the energy that was stored produces a pulse that travels up the casing string  20  in a backwards or left-hand rotation. Engagement of the clutch assembly  78  also prevents the slips  48  from becoming inadvertently unset from the casing  20 , which prevents the work string  22  from unattaching from the casing string  20 . 
         [0025]    It can be seen that the invention provides a casing manipulation assembly  36  that includes a casing manipulation tool  38  that is used to engage a casing member  20  via rotation of a mandrel  50  within the casing manipulation tool  38 . The casing manipulation assembly  36  also includes a torque locking mechanism  40  that can be engaged using hydraulic fluid pressure to lock the casing manipulation tool  38  against counter-rotation. In an exemplary method of operation, the casing manipulation tool  38  is first actuated to set the slips  48 . Thereafter, the torque locking mechanism  40  is engaged using hydraulic fluid pressure. Once the torque locking mechanism  40  is engaged, the top drive unit  24  can rotate the work string  22  to, in turn, rotate the casing member  20 . 
         [0026]    Those of skill in the art will recognize that numerous modifications and changes may be made to the exemplary designs and embodiments described herein and that the invention is limited only by the claims that follow and any equivalents thereof.