WO2002086279A1

WO2002086279A1 - Apparatus for running tubulars

Info

Publication number: WO2002086279A1
Application number: PCT/CA2002/000519
Authority: WO
Inventors: Robert Patrick Appleton
Original assignee: Tesco Corporation
Priority date: 2001-04-19
Filing date: 2002-04-16
Publication date: 2002-10-31
Also published as: GB0109586D0; AU2002249040A1; WO2002086279A8

Abstract

An apparatus (10) for handling tubulars with respect to a borehole (13) includes a mandrel (12) having a plurality of angled faces (16) and an external sliding sleeve (20) carried on the mandrel. The sliding sleeve has connected for sliding movement therewith a plurality of grapples (22). The grapples are positioned to overlie the mandrel faces. At least one of the mandrel faces or the inner surfaces of the grapples are angled such that rotation of the mandrel relative to the grapples causes the grapples to be driven radially outwardly from the mandrel. In use, the apparatus is inserted into a tubular and the grapples are driven outwardly by relative rotation of the grapples and the mandrel to cause the grapples to engage against the inner surface of the tubular in which the apparatus is positioned.

Description

APPARATUS FOR RUNNING TUBULARS

The present invention relates to apparatus for use in the oil and gas exploration and extraction industries. More specifically, the invention relates to an apparatus for running tubulars into a borehole.

In the construction of oil or gas wells it is usually necessary to line the borehole with a string of tubulars known as casing. Because of the length of the casing required, individual sections of casing are typically progressively added to the string as it is lowered into a well from a drilling platform. The section to be added is restrained from falling into the well by some tubular engagement means, typically a spider or the like, and is lowered into the well to position the threaded pin of the casing section adjacent the threaded box of the casing in the well. The sections are then joined by relative rotation of the sections.

It is common practice to use a power tong to torque the connection to a predetermined torque in order to connect the sections of casing. Alternately, a top drive may be used; that is, a top driven rotational system used for drilling purposes.

Where a top drive system is used to make the connection, the use of a spider to restrain the section of casing to be added may be problematic, due to the configuration of the top drive apparatus on the drilling platform. It is therefore known to make use of an apparatus connected to the top drive, which can be inserted into the section of tubular to be added, and engaged therewith to hold the section in place. Such apparatus may comprise one or more grapples which may be hydraulically operated to engage an inner surface of the tubular. Summarv of the Invention

An apparatus has been invented for handling tubular. The apparatus is connectable to a top drive and can be used to grip the tubulars from the inside.

According to a first aspect of the present invention, there is provided an apparatus for running tubulars into and/or out of a borehole, the apparatus comprising a mandrel and a plurality of grapples, wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel.

Rotation in one circumferential direction may act to urge the grapples radially outwardly. Rotation in an opposite circumferential direction may act to urge the grapples radially inwardly.

The apparatus can include further means for moving the grapples radially with respect to the mandrel.

According to a second aspect of the present invention, there is provided an apparatus for running tubulars into and/or out of a borehole, the apparatus comprising a tubular mandrel having a plurality of exterior faces, and a plurality of grapples mounted on the mandrel, each grapple having a inner surface mounted against a corresponding face of the mandrel, wherein at least one of the grapple inner surface and its corresponding mandrel face is angled such that relative rotation of the mandrel and the grapples acts to move the grapples radially with respect to the mandrel.

Thus, an apparatus in accordance with the invention may be connected to a top drive and inserted into a tubular to be lowered into or removed from a borehole. Rotation of the mandrel relative to the grapples will cause the grapples to move outwardly of the mandrel, and so engage or tighten against an inner surface of the tubular section.

In a most preferred embodiment the apparatus is adapted for running tubulars comprising well casing. Preferably the grapples are biased radially inwardly, such that the grapples will automatically disengage from a tubular if there is no force driving them radially outwardly and causing them to remain engaged.

Preferably the faces of the mandrel are angled. Certain embodiments of the invention may be provided with angled faces on both the mandrel and the grapples; either all faces on each or selected faces on each.

Preferably the faces are angled circumferentially. Preferably the faces are angled so as to taper in the same circumferential direction. Thus, rotation of the mandrel in one direction will cause the grapples to all move radially inwardly, while rotation in the other direction will cause the grapples to all move radially outwardly. This will be of assistance in making the connection between tubular sections, as rotation of the apparatus in a first direction may be selected to engage the grapples and tighten the connection between sections, while rotation in the opposite direction will disengage the grapples without loosening the connection, allowing the apparatus to be retrieved.

Preferably the grapples are provided with teeth to facilitate grasping the tubular to be handled. The teeth may be serrated or diamond shaped teeth, or include horizontal and/or vertically aligned whickers.

The angled faces may in addition be angled axially, such that relative axial movement of the mandrel and the grapples causes the grapples to move radially with respect to the mandrel. Thus, the grapples may be engaged with a tubular firstly by axial movement of the mandrel, with fine adjustments being made to the degree of engagement by means of rotation of the mandrel.

The apparatus may further be provided with positive locking means to maintain the grapples in engagement with a tubular should the apparatus otherwise fail. The positive locking means may be provided in conjunction with axially angled faces, and/or in conjunction with circumferentially angled faces. The positive locking means may comprise for example a spring or the like.

In use, the apparatus may be connected to a top drive unit via a threaded connection at its upper end, or to a kelly driven rig via a pump joint latched into an elevator. Both systems have available a means of connecting to a circulating system that will permit the tubular being handled to be filled or circulated at any time during the running operation. In preferred embodiments, the mandrel of the apparatus is equipped with a through bore to permit tubular fill-up and circulation to take place at any time. There may also be provided a packer on the tool to permit isolation of a section of the tubular.

The apparatus can include any number of grapples and mandrel faces in one circumferential arrangement and it can include a plurality of spaced apart circumferential arrangements. In one embodiment, the apparatus further comprises a second plurality of mandrel faces and a second plurality of grapples having inner surfaces, at least one of the mandrel faces or the grapple inner surfaces being angled, the second plurality of mandrel faces and grapples being axially spaced from the first plurality of mandrel faces and grapples. This allows the apparatus to be used to engage more than one tubular section simultaneously, or simply to engage a single tubular section at two locations.

The second plurality of mandrel faces and grapples may have faces or inner surfaces angled in the same direction or a different direction to those of the first plurality. In one embodiment, the faces are tapered in an opposite rotational direction to those of the first plurality so that rotation of the mandrel in either direction, relative to the grapples, may permit selective engagement of one of the plurality of grapples with an internal wall of a tubular.

The apparatus may further comprise a stabbing guide or a bull-nose centralizer to facilitate handling of tubulars.

According to a third aspect of the present invention, there is provided a method of running tubulars into and/or out of a borehole, the method comprising the steps of:

locating in a tubular an apparatus comprising a mandrel and a plurality of grapples wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel; rotating at least one of the mandrel and the grapples, to urge the grapples radially outward with respect to the mandrel, thereby engaging the grapples with a wall of the tubular;

moving the apparatus and the engaged tubular relative to a wellbore; and

rotating at least one of the mandrel and the grapples, to urge the grapples radially inward with respect to the mandrel, thereby disengaging the grapples from a wall of the tubular.

According to a further aspect of the present invention, there is provided a method of casing a wellbore, the method comprising the steps of:

locating in a casing section an apparatus comprising a mandrel and a plurality of grapples wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel;

rotating one of the mandrel and the grapples, to urge the grapples radially outward with respect to the mandrel, thereby engaging the grapples with a wall of the casing;

lowering the apparatus and casing into a wellbore; and rotating one of the mandrel and the grapples, to urge the grapples radially inward with respect to the mandrel, thereby disengaging the grapples from a wall of the casing.

Brief Description of the Drawings

These and other aspects of the present invention will now be described by way of example only and with reference to the accompanying drawings, in which:

Figure 1 shows an axial sectional view of an apparatus in accordance with one embodiment of the present invention;

Figure 2 shows a transverse sectional view through the mandrel of the apparatus of Figure 1 taken along line I Ml;

Figure 3 shows the mandrel of Figure 2 with a plurality of grapples mounted thereon; Figure 4 shows an axial sectional view of an apparatus in accordance with one embodiment of the present invention;

Figure 5 shows a transverse sectional view through the mandrel of the apparatus of Figure 4 taken along line V-V;

Figure 6 shows transverse sectional view through the mandrel of the apparatus of Figure 4 taken along line VI-VI;

Figure 7 shows the mandrel of Figure 4 with a plurality of grapples mounted thereon; and

Figure 8 shows an axial sectional view of another apparatus according to the invention.

Detailed Description of the Present Invention

Referring to Figures 1 to 3, this shows an apparatus 10 for running tubulars 11 such as casing into a borehole 13 in accordance with an embodiment of the present invention. The apparatus 10 comprises a tubular mandrel 12 having a bore 14 formed therethrough along its long axis 12x. The mandrel 12 bears a number of external angled faces 16 on the mandrel 12. Mounted on the mandrel 12 is an external sliding sleeve 20. The sleeve 20 carries a plurality of arms 21 with grapples 22 on their outer ends. The grapples are each set adjacent a corresponding angled face 16 on the mandrel 12. The inner surface 23 of each grapple, that is, the surface adjacent the angled face 16 of the mandrel 12, is also angled to correspond with the mandrel face, while the outer surface of each grapple 22 is provided with serrated teeth 26, for engaging an inner surface of tubular 11.

Figure 2 shows that the faces 16 are angled circumferentially around the mandrel. In other words, in a transverse section through mandrel a line r extending radially from axis 12x of the mandrel would pass non-orthogonally through face 16 such that the angle α defined between line r and face 16, in the circumferential direction would not equal 90°. In the illustrated embodiment, the mandrel faces angle inwardly toward axis 12x in a circumferential direction such that the face side 16' is closer to the center axis 12x than side 16". Figure 3 shows the same transverse section of mandrel 12 as in Figure 2 with grapples 22 mounted thereon. It can be seen from these Figures that the inner surfaces 23 of the grapples 22 are arranged to taper in a complementary direction to the radial circumferential taper of the mandrel faces 16. In this way, a grapple is in its most retracted position when it is positioned closest to side 16' and is driven out away from the mandrel as it is moved towards side 16".

As can be seen from Figure 1 , the mandrel faces 16 are also angled to taper in a radial direction axially along the mandrel 12 and the inner surfaces of the grapples are correspondingly tapered to act in a wedge-type lock with the faces. In the illustrated embodiment, the faces angle inwardly toward axis 12x from their lower ends to their upper ends and grapples taper from their upper ends to their lower ends to ride over the radial axial angle of the faces. In this way, the grapples will be in a retracted position when they are positioned on the upper ends of faces 16.

The apparatus 10 further includes a resilient biasing member 28 extending circumferentially around the apparatus 10 and in contact with the grapples 22. The biasing member serves to bias the grapples 22 radially inward against the mandrel 12, so as to retract the grapples 22 in the absence of any countervailing force. The resilient biasing member can be, for example, an elastomeric o-ring, a c-spring or other means. The mandrel has shoulders 29 built up between adjacent faces 16 to separate the faces and to act as walls against which grapples 22 can butt to limit the degree to which they can slide circumferentially along their corresponding faces.

The sliding sleeve and the mandrel must be connected together in such a way that they can move both axially and rotationally relative to each other. In one embodiment, sleeve is connected through bearings to mandrel to permit rotation and sliding movement thereover. A drive system is provided to act between the sleeve and the mandrel to drive the sleeve axially or rotationally over the mandrel. A shoulder 30 or other means can be used to limit axial movement of the sleeve. The drive system can be, for example, a conventional hydraulic fluid arrangement to permit selective axial movement of the sliding sleeve 20 along the mandrel on actuation of the hydraulic arrangement. ln addition to the components herein described, the apparatus 10 may also optionally incorporate a packer assembly can also be mounted about the mandrel to provide sealing engagement with the inner surface of the tubular; and/or a rubber stabbing guide.

In use, the apparatus 10 functions as follows. The apparatus 10 is first inserted into the bore of tubular 11. The sleeve 20 is held in the retracted position relative to the mandrel to maintain the grapples 22 in a retracted position on their corresponding faces, such that they do not contact the inner surface of the tubular. When the apparatus 10 is at the correct installation depth within the tubular, the sleeve is driven downwards, as by injection of hydraulic fluid into a hydraulic drive assembly. This downward movement relative to the mandrel, presses the grapples 22 against the angled faces 16 of the mandrel 12. The grapples 22 are thus forced outwards, as arms 21 flex, into contact with the inner surface of the tubular to form a mechanical friction grip. To enhance the engagement between the apparatus and the tubular, a top drive or the like is used to apply torque to the mandrel 12, so causing it to rotate. Because the grapples are frictionally gripped to the tubular, the mandrel rotates relative to the grapples 22. This causes the circumferential taper of the mandrel faces 16 to be brought to bear against the grapples 22 thereby further forcing the grapples 22 outward to engage more firmly with the casing section, and so to rotate the casing section along with the apparatus 10. This reduces the risk that the grapples 22 will inadvertently become disengaged from the casing section.

In the illustrated embodiment, wherein the mandrel faces angle inwardly toward axis 12x in a counterclockwise circumferential direction (when viewed from the bottom), rotation of the mandrel also in a counterclockwise direction, as shown by arrow A, relative to the grapples acts to drive them out.

To retrieve the apparatus 10 from the casing section, the mandrel 12 is rotated in the opposite direction until the grapples 22 are retracted out of contact with the inner surface of the tubular or until they are at their most retracted position. The sliding sleeve 20 is then driven upwardly to bring the grapples 22 out of contact with the angled faces 16. The resilient member 28 around the grapples 22 causes them to retract and pull away from the inner surface of the tubular. The apparatus 10 may then be pulled out of the tubular. Referring to Figures 4 to 7, another apparatus 10a is shown having two grapple arrangements. In particular, apparatus 10a includes a mandrel 12a having an upper set of faces 16 and, spaced therebelow, a lower set of faces 18. A sliding sleeve 20a is mounted on mandrel 12a for axial movement thereover. Sliding sleeve 20a has connected thereto a plurality of upper grapples 22a and, connected therebelow by arm 21a, a plurality of lower grapples 24. Upper grapples 22a are each formed and positioned to ride along one corresponding face 16 and each of lower grapples 24 are formed and positioned to ride along one corresponding lower face 18.

As can be seen from Figure 4, the angled mandrel faces 16, 18 are angled to taper in a radial direction axially along the mandrel 12. Figure 5, a sectional view of the mandrel 12 at the location of upper angled faces 16, shows that the faces 16 are also angled circumferentially around the mandrel. Figures 6 and 7 are sectional views of the mandrel 12 at the location of the lower set of angled faces 18, and illustrate that these faces 18 have an equivalent angle of inclination in an opposite circumferential direction to those of faces 16. The grapples 24 have inner surfaces correspondingly tapered so that, when the tool is positioned in a casing section, they can work with faces 18 to create a wedge lock between the mandrel and the inner surface of the casing in the circumferential direction.

Apparatus 10a is shown handling a casing section for casing a wellbore. In particular, apparatus 10a is inserted into a casing section 11 in preparation for engaging it to connect it into a casing string extending into a borehole.

Where the apparatus 10a has two grapple arrangements, and the mandrel faces 16, 18 are of opposite tapers, the apparatus 10a may be used to drive rotation of a casing section in both a clockwise and a counterclockwise direction to connect and also disconnect casing sections. In particular, torque in one direction will cause the upper set of grapples 22 to ride over faces 16 and engage with the casing wall and torque of the mandrel 12a in the opposite direction will cause the second set of grapples 24 to engage with the casing section wall, so allowing the casing section to be rotated to disconnect the section from the casing string. Ref erring to Figure 8, there is shown another apparatus according to the present invention. The apparatus 10b has four grapple arrangements. As such the mandrel 12b includes a first, second, third and fourth set of faces 16b, 17, 18b, 19, respectively, positioned directly adjacent each other and the sliding sleeve 20b has connected thereto a plurality of grapples (only one can be seen in this sectional view) each including four ramps 22b, 23, 24b, 25. The ramps are positioned such that one overlies each face of the mandrel. In this embodiment, in addition to the radial axial angle of the faces, all of faces 16b, 17, 18b and 19 angle inwardly toward axis 12x in the circumferential clockwise direction (when viewed from the top), so that the grapples will be driven radially outwardly when torquing up casing connections using a top drive, which is driven in a clockwise direction when viewed from the top.

Apparatus 10b includes a stabbing guide 40 and a packer 42. A drive system is shown for sliding sleeve 20b including a pair of hydraulic fluid chambers 44, 46.

It will be apparent that many other changes may be made to the illustrative embodiments, while falling within the scope of the invention and it is intended that all such changes be covered by the claims appended hereto.

Claims

Claims:

1. An apparatus for running tubulars into and/or out of a borehole, the apparatus comprising a mandrel and a plurality of grapples, wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel.

2. The apparatus of claim 1 wherein rotation in one circumferential direction acts to urge the grapples radially outwardly and rotation in an opposite circumferential direction acts to urge the grapples radially inwardly.

3. The apparatus of claim 1 further comprising means for moving the grapples radially with respect to the mandrel.

4. An apparatus for running tubulars into and/or out of a borehole, the apparatus comprising a tubular mandrel having a plurality of exterior faces, and a plurality of grapples mounted on the mandrel, each grapple having a inner surface mounted against a corresponding face of the mandrel, wherein at least one of the grapple inner surface and its corresponding mandrel face is angled such that relative rotation of the mandrel and the grapples acts to move the grapples radially with respect to the mandrel.

5. The apparatus of claim 4 wherein the apparatus is connectable to a top drive to apply torque to the mandrel.

6. The apparatus of claim 4 wherein the grapples are biased radially inwardly.

7. The apparatus of claim 4 wherein the faces of the mandrel are angled.

8. The apparatus of claim 7 wherein the mandrel faces are angled circumferentially.

9. The apparatus of claim 8 wherein the mandrel faces are angled in the same direction.

10. The apparatus of claim 4 wherein the inner surfaces of the grapples are angled.

11. The apparatus of claim 7 wherein the grapple inner surfaces are angled circumferentially.

12. The apparatus of claim 8 wherein the grapple inner surfaces are angled in the same direction.

13. The apparatus of claim 4 wherein the grapples are provided with teeth to facilitate grasping the tubular to be handled.

14. The apparatus of claim 4 wherein the faces are angled axially, such that relative axial movement of the mandrel and the grapples causes the grapples to move radially with respect to the mandrel.

15. The apparatus of claim 4 further comprising a positive locking means to maintain the grapples in the outwardly extending position should the apparatus otherwise fail.

16. The apparatus of claim 4 the mandrel of the apparatus is equipped with a through bore to permit tubular fill-up and circulation to take place at any time. There may also be provided a packer on the tool to permit isolation of a section of the tubular.

17. The apparatus of claim 4 further comprising a second plurality of mandrel faces and a second plurality of grapples having inner surfaces, at least one of the mandrel faces or the grapple inner surfaces being angled, the second plurality of mandrel faces and grapples being axially spaced from the plurality of mandrel faces and grapples.

18. The apparatus of claim 17 wherein the second plurality of mandrel faces are angled circumferentially in a different direction than the plurality of mandrel faces.

19. A method of running tubulars into and/or out of a borehole, the method comprising the steps of: locating in a tubular an apparatus comprising a mandrel and a plurality of grapples wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel; rotating at least one of the mandrel and the grapples, to urge the grapples radially outward with respect to the mandrel, thereby engaging the grapples with a wall of the tubular; moving the apparatus and the engaged tubular relative to a wellbore; and rotating at least one of the mandrel and the grapples, to urge the grapples radially inward with respect to the mandrel, thereby disengaging the grapples from a wall of the tubular.

20. A method of casing a wellbore, the method comprising the steps of: locating in a casing section an apparatus comprising a mandrel and a plurality of grapples wherein relative rotation of the mandrel and grapples acts to urge the grapples radially with respect to the mandrel; rotating one of the mandrel and the grapples, to urge the grapples radially outward with respect to the mandrel, thereby engaging the grapples with a wall of the casing; lowering the apparatus and casing into a wellbore; and rotating one of the mandrel and the grapples, to urge the grapples radially inward with respect to the mandrel, thereby disengaging the grapples from a wall of the casing.