FIELD OF THE INVENTION
This invention relates generally to rotary drilling apparatus for oil and gas wells and in particular to apparatus for handling power tongs on the rig floor.
BACKGROUND OF THE INVENTION
Rotary drilling operations for oil and gas wells generally employs a drill string consisting of many joints of drill pipe at the top of the string and several joints of drill collars at the bottom of the string nears the bit.
Periodically during the drilling of a well when the string, partially or entirely, must be removed from the hole. Such cases include the need for changing bits, running casing or for other reasons. Also, as the drilling progresses and the bore hole becomes deeper, additional joints or stands of pipe must be added for drilling to continue.
To add or remove drill pipe or drill collar segments to or from the drill string, the existing connections between the drill pipe or drill collar segments must be broken loose and then rotated multiple times to disengage the threaded connection and separate the segments so the segments may be removed from the drill string. The pipe sections must be rotated clockwise and retightened before drilling can recommence. For these operations, current art utilizes large machines known as power tongs, to hydraulically make these connections. These machines are large and unwieldy and require means to support them and move them around the drill floor.
Current methods for handling power tongs include telescoping arms as well as hydraulically powered linkage mechanisms. These types of mechanisms are complicated and often contain highly loaded components. Such mechanisms are often restricted in their range of motion and travel.
Additionally, linkage mechanisms often do not operate in a linear fashion throughout the extension and retraction travel and are difficult for the operator to become skilled at operating. In some instances, the level of expertise required is so great that the designers have incorporated expensive computerized controls.
SUMMARY OF THE INVENTION
The present invention provides for an economical and versatile alternative method for controlling the movement of rig tools about the rig floor. The central entity in the invention is a boom of substantially fixed length supported by an attached support structure. The boom is moveable axially with respect to the support structure and is fully or partially supported by bearing means incorporated within said support structure. Incorporated within said support structure is a means for linearly moving the arm with respect to the support structure. The support structure may be mounted on a fixed post or on an existing portion of the rig structure.
The preferred embodiment of a manipulator of the present invention has a boom of a box-beam configuration supported by flanged rollers incorporated into a bearing housing. The bearing housing is supported by a slewing housing below it. The slewing housing is supported by a cylindrically tubular post and is pivotable about the vertical axis of the post. The tubular post is removable and supported at its lower end by a socket affixed to the rig structure. The bearing housing is pivotable in a vertical direction with respect to the slewing housing using one or more hydraulic cylinders. The power tong is supported at the outermost end of the boom using a gimble suspension and may also incorporate a swivel means to allow rotation of the power tong below the gimble. The boom is moveable in a horizontally axial direction with respect to the bearing housing by means of one or more rack and pinion gear drives. The action of the gear drive causes the boom and, thereby, the power tong to be moved toward and away from the fixed post location toward and away from well center and other locations about the rig floor. When the stewing motion allowed by the slewing housing is added to the linear motion caused by the gear drive, it is possible to position the power tong over a large area of the rig floor. The action of the hydraulic cylinders causes the bearing housing to tilt vertically with respect to the slewing housing, thereby causing the end of the boom to rise, thus raising the level of the power tong.
In alternate embodiments of manipulators of the present invention, the power tong may be suspended by a cable attached to the rig structure well above the rig floor. In these cases, a manipulator of the present invention would be similar in its basic configuration but required to react different and, generally lesser, loadings. In these alternative embodiments, the bearing and slewing housings and the related post or other support structures provide support predominately in lateral directions only and react the side loads imposed by the non-vertical components of the cable loading. This arrangement would decrease the vertical loads imposed on the boom and other structures, allowing them to be made lighter and/or increase the range of motion of the arm in one or more directions. The gear drive would move the boom as described above and such configurations may also provide a slewing capability, either manually or powered, to allow rotation of the boom about a fixed vertical axis. The external supporting structure may be allowed to be rotated manually but be provided with fixed stops for the particular locations such as well center or the mousehole. In the case of tools suspended from a cable, provisions must be made to either allow the power tong to move vertically with respect to the boom or to allow the boom and bearing housing to pivot vertically to follow such vertical motion of the power tong.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view of a manipulator of the present invention illustrating the boom in the retracted position.
FIG. 2 is a partially sectioned view similar to FIG. 1.
FIG. 3 is a sectional view as defined in FIG. 2.
FIG. 4 is a side view similar to FIG. 1 illustrating the boom in the extended position.
FIG. 5 is a side view similar to FIG. 2 illustrating the boom in the extended position and the bearing housing pivoted vertically.
FIG. 6 is a top view of FIG. 1 illustrating the boom in the retracted condition and showing the power tong in a position away from well center.
FIG. 7 is a top view similar to FIG. 6 illustrating the boom in a partially extended condition and showing the power tong in position at well center.
FIG. 8 is a top view similar to FIG. 7 illustrating the boom in an extended and slewed condition and showing the power tong in position at the mousehole. It also shows the power tong rotated about the end of the boom to properly align with the tilt of the mousehole.
FIG. 9 is a side view of an alternate embodiment of a manipulator of the present invention showing the end of the boom suspended from a cable and hydraulic cylinder.
FIG. 10 is a side view of an alternate embodiment of a manipulator of the present invention wherein the rig tool is suspended from a cable and the manipulator is supported directly by the rig structure.
DETAILED DESCRIPTION OF THE INVENTION
The manipulators of the present invention are used to move around rig tools such as power tongs to different locations about the rig floor.
The manipulators of the present invention have a boom of a substantially fixed length. The power tong is attached to one end of the boom. The boom is supported along a portion of its length by bearings incorporated into a bearing housing. The boom is moveable with respect to the bearing housing allowing the attached power tong to be moved to various locations on the rig floor.
FIGS. 1 through 10 show how the manipulators of the present invention are assembled and operate.
FIG. 1 is a side view of a manipulator of the present invention. The power tong 1 is supported from the boom 5 by a gimble mechanism 6 and suspension link 7. The gimble mechanism 6 may or may not include a swivel means to allow the rotation of the power tong below the gimble mechanism 6. Boom 5 is supported by bearing housing 4. Bearing housing 4 is in turn supported by slewing housing 11. Slewing housing 11 is supported by post 2. Post to is removable from and supported by socket 25. Socket 25 is affixed to the rig structure 3.
FIG. 2 is a partially sectioned view of a manipulator of the present invention. The boom 5 is supported by rollers 10 incorporated in the bearing housing 4. One or more gear racks 8 are affixed to the boom 5. One or more hydraulic motors 16 are attached to the bearing housing. A pinion gear 15 is attached to each of the hydraulic motors 16. When the hydraulic motors 16 are actuated, the pinions 15 acting upon the gear racks 8 cause the boom 5 to move axially through the bearing housing 4. The bearing housing 4 is supported by slewing housing 11 by means of a pivot pin 14 and one or more hydraulic cylinders 9. The slewing housing 11 is vertically supported by thrust bearing 12 and cylindrical post 2. The slewing housing 11 incorporates upper slewing rollers 13 and lower stewing rollers to react overhung loading. Upper slewing roller 13b is behind and hidden by upper slewing roller 13 and lower slewing roller 13c is behind and hidden by lower slewing roller 13a and are not shown in this view.
FIG. 3 is a sectional view of a manipulator of the present invention as defined in FIG. 2 showing the arrangement of upper slewing rollers 13 and 13b, lower slewing rollers 13a and 13c mounted in slewing housing 11 and acting on cylindrical post 2
FIG. 4 is a side view of a manipulator of the present invention similar to FIG. 1 showing the boom 5 in the extended condition with respect to bearing housing 4. The extension of boom 5 is the result of the hydraulic motor(s) 16 causing the rotation of pinion gear(s) 15. The rotation of pinion gear(s) 15 acting upon gear rack(s) 8 causes the linear movement of boom 5 attached thereto.
FIG. 5 is a side view of a manipulator of the present invention similar to FIG. 4 showing the extended boom 5 in the elevated condition. The bearing housing 4 is attached to the slewing housing 11 by pivot pin 14. Actuating hydraulic cylinder(s) 9 causes the bearing housing 4 to pivot about pivot pin 14, changing the elevation of the power tong 1 by the tilting of boom 5. The gimble mechanism 6 allows the power tong 1 to remain the same vertical orientation as the boom 5 rotates with respect to the horizontal plane.
FIG. 6 is a top view of a manipulator of the present invention showing boom 5 in the retracted condition with respect to bearing housing 4. Slewing housing 2 is directly below bearing housing 4 and post 2 is directly below stewing housing 4.
FIG. 7 is a top view of a manipulator of the present invention similar to FIG. 6 showing boom 5 in a partially extended condition with respect to bearing housing 4 with power tong 1 in position at the well center 23.
FIG. 8 is a top view of a manipulator of the present invention similar to FIG. 6 showing boom 5 in a further extended position with respect to bearing housing 4. Additionally, FIG. 8 shows boom 5, bearing housing 2 and slewing housing 11 slewed with respect to post 2 thus allowing power tong 1 to be positioned at mouse hole position 24. Power tong 1 is shown swiveled with respect to gimble 6 so that the angle of the power tong 1 may be aligned with the angle of the tilted mouse hole if required.
FIG. 9 shows how the manipulator of the present invention maybe used with a hanging cable 18 and hydraulic cylinder 19 to increase the extension and/or decrease the structural requirements of boom 5a, bearing housing 4a, slewing housing 11a and post 2a. Bearing housing 4a incorporates a drive motor 16a and attached pinion gear 15a behind it and not shown acting upon a gear rack 8a affixed to boom 5a to provide linear movement of boom 5a.
FIG. 10 shows how a manipulator of the present invention may be used with a hanging cable 18a and hydraulic cylinder 19b supporting power tong 1. In this configuration the manipulator is supported by a portion the rig structure such as a derrick leg 22. The slewing housing 11b is supported by an attachment bracket 21. The stewing housing 11b supports the bearing housing 4b. The bearing housing 4b in turn supports the boom 5b. At it's outboard end, boom 5b is equipped with a sheave 26 or other bearing means to allow it to push directly against the hanging cable or the rod of the hydraulic cylinder. Bearing housing 4b incorporates a drive motor 16b and attached pinion gear 15b acting upon a gear rack 8b affixed to boom 5b to provide linear movement of boom 5b. This configuration eliminates the need for the boom to pivot to follow the change in elevation of the power tong.
The invention is not limited to the specific embodiments as described above, but rather is applicable to all variations within the scope of the claims.
Patent Application
20080245522
