1. Field of the Invention
The invention relates generally to a torque locking mechanism used in conjunction with casing manipulation systems.
2. Description of the Related Art
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.
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.
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.
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.
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.
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:
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
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.
An annular piston 70 (
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
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.
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.
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
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.
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.