Method and apparatus for connecting tubulars using a top drive

Abstract

An apparatus for facilitating the connection of tubulars, said apparatus comprising a winch, at least one wire line, and a device for gripping the tubular, the arrangement being such that, in use, the winch can be used to winch said at least one wire and said device to position a tubular below said top drive.

Description

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a method and apparatus for facilitating the connection of tubulars using a top drive and is, more particularly but not exclusively, for facilitating the connection of a section or stand of casing to a string or casing.

2. Description of the Related Art

In the construction of wells such as oil or gas wells, it is usually necessary to line predrilied holes with a string of tubulars known as casing. Because of the size of the casing required, sections or stands of say two sections of casing are connected to each other as they are lowered into the well from a platform. The first section or stand of casing is lowered into the well and is usually restrained from falling into the well by a spider located in the platform's floor. Subsequent sections or stands of casing are moved from a rack to the well centre above the spider. The threaded pin of the section or stand of casing to be connected is located over the threaded box of the casing in the well to form a string of casing. The connection is made-up by rotation therebetween.

It is common practice to use a power tong to torque the connection up to a predetermined torque in order to perfect the connection. The power tong is located on the platform, either on rails, or hung from a derrick on a chain. However, it has recently been proposed to use a top drive for making such connection.

Prior to the present invention, pipe handling devices moved pipes to be connected to a tubular string from a rack to the well centre using articulated arms or, more commonly, a pipe elevator suspended from the drilling tower.

The present invention provides an alternative to these devices.

SUMMARY OF THE INVENTION

Accordingly, a first aspect of the present invention provides an apparatus for facilitating the connection of tubulars, said apparatus comprising a winch, at least one wire line and a device for gripping a tubular the arrangement being such that, in use, the winch can be used to winch said at least one wire and said device to position a tubular below said top drive.

Further features are set out in claims 2 to 6.

According to a second aspect of the present invention there is provided a method of facilitating the connection of tubulars using a top drive and comprising the steps of attaching at least one wire to a tubular, the wire depending from the top drive or from a component attached thereto, and winching the wire and the tubular upwards to a position beneath the top drive.

According to a third aspect of the present invention there is provided an apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising an elevator and a pair of bails, characterized in that said elevator is, in use, movable in relation to said pair of bails.

According to a fourth aspect of the present invention there is provided: an apparatus for facilitating the connection of tubulars using a top drive, said apparatus comprising an elevator and a pair of bails, characterized in that said elevator is, in use, movable relative to said pair of bails.

BRIEF DESCRIPTION OF THE DRAWINGS

For a better understanding of the present invention and in order to show how the same may be carried into effect reference will now be made, by way of example, to the accompanying drawings in which:

FIGS. 1 a to 1e are perspective views of an apparatus in accordance with a first embodiment of the present invention at various stages of operation; and

FIGS. 2 a to 2d are perspective views of an apparatus in accordance with a second embodiment of the invention at various stages of operation.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Referring to FIGS. 1a to 1e there is shown an apparatus which is generally identified by reference numeral 1.

The apparatus 1 comprises a clamp 2 for retaining a tubular 3. The clamp 2 is suspended on wires 4, 5 which are connected thereto on opposing sides thereof. The wire 5 passes through an eye 6 in lug 7 which is attached to a spherical bearing in arm 8 of a suspension unit 9 at the point at which the arm 8 is connected to a hydraulic motor. The wire is connected to the hydraulic motor 10 in a corresponding manner. The suspension unit 9 is of a type which enables displacement of the tubular 3 when connected to a tool 17 (see below), relative to a top drive 13, along a number of different axes. The wires 4, 5 pass across the suspension unit 9 and over pulley wheels 11 which are rotatably arranged on a plate 12. The plate 12 is fixed in relation to a top drive generally identified by reference numeral 13. The wires 4, 5 then pass over drums 14 to which the wires 4, 5 are also connected. The drums 14 are rotatable via a hydraulic winch motor 15.

In use, the clamp 2 is placed around a tubular below a box 16 thereof. The hydraulic winch motor 15 is then activated, which lifts the tubular 3 (conveniently from a rack) and towards a tool 17 for gripping the tubular 3 (FIG. 1b). The tubular 3 encompasses the tool 17 at which point the hydraulic winch motor 15 is deactivated (FIG. 1c). During this operation the elevator 18 is held away from the tool 17 by piston and cylinders 19, 20 acting on bails 21 and 22. The suspension unit 9 allows the hydraulic motor 10 and the arrangement depending therebelow to move in vertical and horizontal planes relative to the top drive 13. The eyes 6 in lugs 7 maintain the wires 4 and 5 in line with the tubular 3 during any such movement. The tool 17 may now be used to connect the tubular to the tubular string. More particularly, the tool may be of a type which is inserted into the upper end of the tubular, with gripping elements of the tool being radially displaceable for engagement with the inner wall of the tubular so as to secure the tubular to the tool. Once the tool is secured to the tubular, the hydraulic motor 10 is activated which rotates the tool 17 and hence the tubular 3 for engagement with a tubular string held in a spider.

The clamp 2 is now released from the tubular 3, and the top drive 13 and hence apparatus 1 is now lifted clear of the tubular 3. The elevator 18 is now swung in line with the apparatus 1 by actuation of the piston and cylinders 19 and 20 (FIG. 1d).

The top drive 13 is then lowered, lowering the elevator 18 over the box 16 of the tubular 3. The slips in the elevator 18 are then set to take the weight of the entire tubular string. The top drive is then raised slightly to enable the slips in the spider to be released and the top drive is then lowered to introduce the tubular string into the borehole.

Referring to FIGS. 2a to 2d there is shown an apparatus which is generally identified by reference numeral 101.

The apparatus 101 comprises an elevator 102 arranged at one end of bails 103, 104. The bails 103, 104 are movably attached to a top drive 105 via axles 106 which are located in eyes 107 in the other end of the bails 103, 104. Piston and cylinders 108, 109 are arranged between the top drive 105 and the bails. One end of the piston and cylinders 108, 109 are movably arranged on axles 110 on the top drive. The other end of the piston and cylinders 108, 109 are movably arranged on axles 111, 112 which are located in lugs 113, 114 located approximately one-third along the length of the bails 103, 109.

The elevator 102 is provided with pins 115 on either side thereof and projecting therefrom. The pins 115 are located in slots 116 and 116g. A piston 117, 118 and cylinder 119, 120 are arranged in each of the bails 103, 104. The cylinders are arranged in slot 121, 122. The piston 117, 118 are connected at their ends to the pins 115. The cylinders 119, 120 are prevented from moving along the bails 103, 104 by cross members 123 and 124. A hole is provided in each of the cross members to allow the pistons to move therethrough.

In use, a tubular 125 is angled from a rack near to the well centre. The tubular may however remain upright in the rack. The clamp 102 is placed around the tubular below a box 126 (FIG. 2a). The top drive is raised on a track on a derrick. The tubular is lifted from the rack and the tubular swings to hang vertically (FIG. 2b). The piston and cylinders 108, 109 are actuated, extending the pistons allowing the bails 103, 104 to move to a vertical position. The tubular 125 is now directly beneath a tool 127 for internally gripping and rotating the tubular 125 (FIG. 2c). The pistons 117, 118 and cylinders 119, 120 are now actuated. The pins 115 follow slot 116 and the clamp 102 moves upwardly, lifting the tubular 125 over the tool 127 (FIG. 2d). The tool 127 can now be actuated to grip the tubular 125.

At this stage the elevator 102 is released and the top drive 105 lowered to enable the tubular 125 to be connected to the string of tubulars in the slips and torqued appropriately by the top drive 105.

The pistons 117, 118 and cylinders 119, 120 are meantime extended so that after the tubular 125 has been connected the top drive 105 can be raised until the elevator 102 is immediately below the box. The elevator 102 is then actuated to grip the tubular 125 firmly. The top drive 105 is then raised to lift the tubular string sufficiently to enable the wedges in the slips to be withdrawn. The top drive 105 is then lower to the drilling platform, the slips applied, the elevator 102 raised for the tubular 125 and the process repeated.

While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.

Claims

1. A method for facilitating the connection of tubulars using a top drive, comprising: connecting an elevator to the top drive or a component attached to the top drive using a pair of bails;using the elevator to move a first tubular to a position below the top drive;gripping an inner wall of the first tubular and supporting the weight of the first tubular with the top drive; androtating the first tubular using the top drive, thereby connecting the first tubular to a second tubular.

2. The method of claim 1, further comprising using the elevator to move the first tubular in relation to the pair of bails towards or away from the top drive for gripping the first tubular.

3. The method of claim 1, wherein the first tubular and the second tubular comprise casings.

4. The method of claim 1, wherein moving the first tubular to the position below the top drive comprises moving the first tubular into axial alignment with the top drive.

5. A method of connecting casing sections by using a top drive, comprising: closing a slip around a first casing section;engaging an elevator with a second casing section;operating a bail actuator to move the elevator and the second casing section into substantial alignment with the top drive;gripping an inner wall of the second casing section and supporting a weight of the second casing section with the top drive;rotating the second casing section using the top drive to join the second casing section to the first casing section to form a joint and a casing string;supporting the weight of the casing string with the top drive; andopening the slip.

6. The method of claim 5, wherein the top drive includes at least one radially displaceable gripping element for engagement with the inner wall of the second casing section.

7. The method of claim 5, further comprising compensating for a weight of the second casing section.

8. The method of claim 5, wherein the elevator is coupled to the top drive using at least one bail.

9. The method of claim 8, wherein operating the bail actuator to move the elevator comprises rotating the at least one bail about a substantially horizontal axis.

10. The method of claim 9, further comprising moving the second casing section axially relative to the top drive to a position to be gripped by the top drive.

11. The method of claim 10, wherein moving the second casing section axially relative to the top drive comprises moving the elevator closer to a rotational axis of an output of the top drive.

12. The method of claim 9, wherein at least two bails are used to couple the elevator to the top drive.

13. The method of claim 9, further comprising moving the elevator closer to a rotational axis of an output of the top drive.

14. The method of claim 10, wherein the top drive includes at least one radially displaceable gripping element for gripping the inner wall of the second casing section.

15. The method of claim 14, wherein the gripping element is disposed on a gripping member operatively connected to the top drive.

16. The method of claim 14, wherein the gripping element moves radially outward to engage the inner wall of the second casing section.

17. The method of claim 5, wherein the elevator is coupled to the top drive using at least two bails, wherein each of the at least two bails is located substantially equidistant from a vertical axis of the top drive.

18. The method of claim 17, wherein the each of the at least two bails share a common axis of rotation.

19. The method of claim 5, wherein the bail actuator comprises at least one piston and cylinder assembly.

20. The method of claim 5, wherein the slip is a component of a spider.

21. An apparatus for connecting casing sections by using a top drive, comprising: at least one elevator;at least one bail operatively coupled to the top drive at one end and the at least one elevator at another end;an actuator operatively coupled to the at least one bail and configured to rotate the at least one bail about a horizontal axis, whereby the at least one elevator is moved from a first location substantially below the top drive to a second location out from under the top drive; andat least one gripping element operatively coupled to the top drive and configured to be radially displaceable for engagement with an inner wall of a casing.

22. The apparatus of claim 21, wherein the at least one elevator is pivotally coupled to the at least one bail.

23. The apparatus of claim 21, wherein the at least one elevator is adapted to maintain the casing in a substantially vertical position as the casing is moved into alignment with the vertical axis.

24. The apparatus of claim 23, wherein the at least one gripping element is rotatable by the top drive.

25. The apparatus of claim 21, wherein each of the at least two bails are equidistant from the vertical axis.

26. The apparatus of claim 21, wherein the at least two bails share a common axis of rotation.

27. The apparatus of claim 21, further comprising an axial actuator adapted to move the at least one elevator closer to the pivot point.

28. The apparatus of claim 21, wherein at least two bails are coupled to the at least one elevator.

29. A method of connecting casings using a top drive assembly, comprising: providing a top drive assembly having a top drive and at least one radially displaceable gripping element for gripping a casing;supporting an elevator from the top drive assembly with at least one bail, the at least one bail having an actuator coupled thereto, the actuator adapted to pivot the at least one bail about a horizontal axis;closing a slip around a first casing;engaging a second casing with the elevator;moving the second casing to a well center by operating the actuator;gripping the second casing with the top drive assembly;threading the second casing to the first casing by rotating an output of the top drive to form a joint and a casing string;opening the slip;lowering the casing string through the slip;closing the slip around the casing string; anddisengaging the top drive assembly from the casing string.

30. The method of claim 29, wherein the horizontal axis intersects a central axis of the top drive.

31. The method of claim 29, wherein the slip comprises a component of a spider.