GB2264736A

GB2264736A - Gripper head beam

Info

Publication number: GB2264736A
Application number: GB9303368A
Authority: GB
Inventors: John Kloumann; Graham Evans
Original assignee: James Howden and Co Ltd
Current assignee: James Howden and Co Ltd
Priority date: 1992-03-04
Filing date: 1993-02-19
Publication date: 1993-09-08
Also published as: NO930759L; GB9303368D0; NO930759D0

Abstract

A gripper head beam 24 is pivotally mounted in a pipe handling apparatus, said beam comprising: a beam body; gripper means 28 mounted on said body and adapted to grip a pipe; and, laterally extending engagement means at one end of said beam body, said engagement means being engageable with an end of the pipe to assist in providing a support for the pipe as it is moved towards a position in which its axis is vertical. In a first embodiment (Fig 1) a foot 34 on a telescopic arm engages and supports the lower end of the pipe 30. In a second embodiment (not shown) an additional gripper engages the shoulder of a pipe box at the upper end of the pipe. <IMAGE>

Description

GRIPPER HEAD BEAM The present invention relates to a gripper head beam, for use in handling pipes between a rack where they are stored horizontally and their point of use, where they are substantially vertical. This finds application in oil drilling, when the pipes form a drill string.

In general, a gripper.head beam has two or more gripping means by which a pipe is gripped, which the head is manoeuvred from a horizontal position at a pipe rack to a vertical position above the drill deck.

Considerable reliance is therefore placed on the friction between the gripping means and the pipe. The weight of the pipe can be significant (up to 5 tons) so that the consequence of gripper unreliability may be grave.

According to the present invention there is provided a gripper head beam being pivotally mounted in a pipe handling apparatus, said beam comprising: a beam body; gripper means mounted on said body and adapted to grip a pipe; and, laterally extending engagement means at one end of said beam body, said engagement means being engageable with an end of the pipe to assist in providing a support for the pipe as it is moved towards a position in which its axis is vertical.

Advantageously, the engagement means are adapted to provide axial support by engagement with an axially downwardly facing surface of the pipe. Suitably the engagement means are movable laterally of the gripper head beam, and axially of the pipe.

In one preferred embodiment the engagement means is a foot adapted to engage the lower end of the pipe. In another preferred embodiment, the engagement means comprises a further gripper means adapted to grip the pipe adjacent its upper end, and more preferably at the upset tool box end.

The invention will be further understood from the following description, when taken together with the attached drawings which are given by way of example only and in which: Figure 1 is a schematic side elevation of one embodiment of the invention shown in use with a carriage for mounting pipes on an oil rig; and, Figures 2 to 4 are schematic side elevations of a second embodiment of the invention.

Referring now to the drawing, it will be seen that a pipe rack 10 is mounted at a spaced location from the vertical axis 12 of an oil rig which is shown schematically at 14. Extending longitudinally between the pipe rack 10 and the axis 12 is a track 14 usually in the form of a pair of rails. Axially movable along this track 14 is a carriage 16. The movement of the carriage is under the action of any suitable means (not shown) which may, for example, be in the form of a variable speed rack and pinion drive, powered by a self-contained hydraulic power pack mounted on the carriage. Other methods of drive include a chain or winch or a simple electric motor drive.

Pivotally mounted at 18 on the carriage is a boom 20 which is capable of being raised and lowered about the pivot point 18 by a hydraulic ram arrangement 22. The boom 20 is pivotally mounted at its inboard end 18 and has, at its outboard end 23 a pivotally mounted gripper head beam 24, pivoting of which is brought about by a hydraulic cylinder 26 or other means, such as a rotary actuator.

The gripper head beam 24 is shown as having two hydraulically operated gripper heads 28 which are adapted to grip any of the pipes 30 in the pipe rack 10. In Figures 1 and 4 of the drawings the lowest of the pipes 30 is shown in full line as being gripped.

It will be noted that the gripper head beam 24 has a telescopic end portion 32 which again may be hydraulically controllable and at the free end of the telescopic end 32 there is provided a foot 34 which extends laterally from the end of the beam and is adapted to engage the end of the pipe 30 being gripped. Preferably an end cap (not shown) is mounted on the foot, this having a peripheral skirt and/or a central spike with which the end of the pipe is engaged. The end cap may be replaceable by other end caps having peripheral skirts of a different diameter to accommodate pipes of a different diameter.

One would need to provide a number of different end caps to suit different pipe sizes, but in normal operation, particularly in producing a drill string, one would be using for an extended period pipes of the same diameter so this does not pose any real problem. Additionally, or alternatively, one could provide a central spike, which could be tapered, to engage the interior of a pipe end.

Finally, the pipe rack 10 is shown as being mounted on a transversely movable shuttle system 36 which enables each pipe in the pipe rack 10 to be positioned immediately below the gripper beam 24 and its grippers 28.

Figure 1 illustrates how the apparatus operates.

In practice, with the carriage 16 in its fully retracted position, that is to say as shown slightly to the left of the full line position, and indicated by the reference numeral 38, a cassette 10 of pipes 30 is positioned underneath the track 14 by the shuttle 36. The gripper heads 28 are opened and the gripper head beam 24 is lowered, by operation of the hydraulic rams 22 and 26. Sensors (not shown) mounted within the gripper head contact the pipe and this contact stops the lowering movement produced by the rams 22,26.

The carriage 16 is then moved forwardly, that is to say to the right, until the foot 34 engages the end of the pipe. A sensor (not shown) on the foot 34 stops the carriage movement and initiates closure of the gripper heads 28.

Once the pipe is gripped, it is lifted by means of operation of the rams 22,26, and the carriage is moved to the right. Various positions of the pivot 18 are indicated in the drawing and it will be appreciated that as the pivot 18 moves to the right and the boom 20 and gripper head beam 24 are pivoted upwardly, so the pipe gripped is moved to a more vertical position. Finally, it will arrive so that the axis of the pipe is on the axis 12 of the rig 14.

During this lifting motion, the foot 34 provides a significant support for the weight of the pipe 30 and the gripper heads do not have to prevent axial movement of the pipe, but only serve to retain the pipe.

Once the pipe is in the correct vertical position, the pipe is attached to, and the weight taken by, the top drive system of the rig or other means. This is facilitated by the presence of the foot 34. The top drive system raises the pipe to clear the foot 34 and the grippers 28 are then released.

The carriage 16 is then moved back towards the left and the boom 20 and gripper head beam 24 are lowered and returned back to the start position 38 on the track 14.

It will be appreciated that the structure of the present invention is a relatively safe structure, there being little chance of the pipes being dropped, because of the simplicity of operation, this being a simple reciprocating motion of the carriage and the operation, e.g., hydraulically, of a boom and a beam, the pipe being supported all the time by the foot 34.

As an alternative, instead of the track 14 being fixed, it could be mounted on a wheeled gantry which will permit the gantry, complete with the tracks and carriage and all its component parts either to traverse the pipe deck or to traverse the width of the pipe rack. If the apparatus traverses the pipedeck, then the apparatus becomes a "stand alone" system and will not require any feeder device, such as the shuttle system 36. If the traverse is limited roughly to the width of the pipe rack, then the apparatus can deal with the indexing operation to pick up the pipes from the rack, thereby reducing the shuttle system to that of a simple conveyor arrangement.

Figures 2 to 4 show a second embodiment of the invention, also in use with a pipe carriage for an oil rig.

In this embodiment, the gripper head beam comprises a further gripper means 40 adapted to engage pipe 30. Gripper 40 is selectively movable laterally of the gripper head beam and parallel to the axis of pipe 30, preferably by means of a telescopically extensible arm 42.

In this embodiment a rack and pinion arrangement (not shown) is used, although if the stroke needed is suitable a hydraulic cylinder may be used. Gripper 40 is preferably used in a position when it is above the gripper head beam, but it may, if convenient, be used beneath it. In use, the gripper head 40 is initially used as a conventional gripper in a head beam. The initial operation of the carriage and beam in Figure 2 is similar to the initial operation described in connection with Figure 1, but differs in that whereas the carriage is moved to engage foot 34 with the end of the pipe to be gripped, gripper 40 operates as do grippers 28, i.e. conventionally, but spaced apart from the main body of the gripper head beam.

As shown in Figures 3 and 4 carriage assembly and gripper head beam are then controlled so that the pipe 30 is aligned with the axis 12 of the rotary table or the axis 12' of the mousehole on the drill deck.

The pressure with which grippers 28 hold the pipe is then relieved to the extent that the pipe may slide axially while still being retained laterally. This sliding is then effected by controlled retraction of arm 42, so that the pipe may be stabbed into the drill pipe or casing string.

If the gripper 40 is at the upper end of the gripper head beam, as shown in Figures 2 to 4, it may provide support via the upset box end of the pipe. Thus the main grippers 28 need only lightly grasp the pipe, since it is positively axially supported by the engagement of the gripper 40 with the upset box end of the pipe.

In a presently preferred embodiment of the invention, gripper 40 is capable of supporting the weight of the pipe alone so that grippers 28 are used for lateral support only, and has a stroke of approximately 3.5m compared to a standard maximum pipe length of 14m.

Claims

1. A gripper head beam being pivotally mounted in a pipe handling apparatus, said beam comprising: (a) a beam body; (b) gripper means mounted on said body and adapted to grip a pipe; and, (c) laterally extending engagement means at one end of said beam body, said engagement means being engageable with an end of the pipe to assist in providing a support for the pipe as it is moved towards a position in which its axis is substantially vertical.

2. A gripper head beam according to claim 1 wherein the engagement means provide axial support by engagement with an axially downwardly facing surface of the pipe.

3. A gripper head beam according to claim 1 or 2 when the engagement means are movable laterally of the gripper head beam, and axially of the pipe.

4. A gripper head beam according to claim 1, 2 or 3 wherein the engagement means is a foot adapted to engage the lower end of the pipe.

5. A gripper head beam according to claim 3 further comprising a sensor on said foot adapted to sense engagement of said foot with the end of the pipe.

6. A gripper head beam according to claim 4 or 5 further comprising a replaceable end cap on said foot, said cap having a skirt and/or a central spike adapted to engage the end of the pipe.

7. A-gripper head beam according to claim 1, 2 or 3 wherein the laterally extending engagement means comprise a further gripper means adapted to grip the pipe.

8. A gripper head beam according to claim 7 wherein the further gripper means are adapted to grip the pipe adjacent its upper end.

9. A gripper head beam according to claim 7 or 8 wherein the further gripper means are reciprocable towards and/or away from the beam body so as to drive the pipe along its axis.

10. A gripper head beam according to claim 7, 8 or 9 wherein the further gripper means are reciprocable by means of a rack and pinion.

11. A gripper head beam according to claim 7, 8 or 9 wherein the further gripper means are reciprocable by means of a hydraulic cylinder.

12. A gripper head beam according to any one of claims 7 to 11 wherein the further gripper means are reciprocable so as controllably to insert an aligned pipe into a mousehole or abut an aligned pipe against the drill or casing string.

13. A gripper head beam constructed and arranged to operate substantially as hereinbefore described with reference to the attached Figures.

14. A pipe handling apparatus comprising a gripper head beam according to any preceding claim, and means to effect movement of said gripper head beam between a substantially horizontal position adjacent a pipe deck on an oil rig, and a substantially vertical position above the drill deck of the oil rig.