TOOL FOR INSIDE CHIP SEPARATING PROCESSING OF A TUBE AND METHOD FOR USING THE TOOL

Abstract

A tool is for inside chip-separating processing of a tube. The tool has a housing which is rotatable around a center axis of the tool, a blade holder which is rotatable around an axis of rotation, there being a plurality of blades positioned along the periphery of the blade holder, and a guide element which is arranged to guide the blade holder between an active position and a passive position. Each of the blades has a surrounding cutting edge which forms a working plane which is arranged perpendicularly to the centre axis of the tool. The blades are arranged for alternating contact with the tube when the blade holder is rotating and is in the active position.

Claims

1.-15. (canceled)

16. A tool for inside chip-separating processing of a tube, wherein the tool comprises: a housing which is rotatable around a center axis of the tool; at least two blade holders each comprising a plurality of blades positioned along the periphery of each blade holder; and guide elements arranged to guide the blade holders between an active position and a passive position, wherein each of the blades is arranged in use to alternatingly contact the tube when the blades are in contact with the tube, the housing is rotating and the blade holders are rotating and in the active position; wherein each blade holder is rotatable around a center axis of the blade holder such that the blades alternatingly contact the tube in use.

17. The tool in accordance with claim 16, wherein each of the blades is arranged to rotate around its center axis when the blades are in contact with the tube, the housing is rotating and the blade holder is in the active position.

18. The tool in accordance with claim 16, wherein the center axes of the blades are parallel.

19. The tool in accordance with claim 16, wherein each of the blades has a surrounding cutting edge which forms a working plane; wherein an angle between the working planes of the blades and the working plane of the tool is between 3 and 6 degrees.

20. The tool in accordance with claim 16, wherein the blades have two-sided support.

21. The tool in accordance with claim 16, wherein the blade holders are freely rotatable.

22. The tool in accordance with claim 16, wherein the blade holders are driven.

23. The tool in accordance with claim 16, wherein the guide element is pivotably connected to the housing.

24. The tool in accordance with claim 16, wherein the guide element is displaceably connected to the housing.

25. The tool in accordance with claim 24, wherein the guide element is connected to a linear actuator comprising a wedge-shaped end portion arranged to move the guide element in a radial direction.

26. The tool in accordance with claim 16, wherein the tool includes a rounded end portion.

27. A system for casing milling of a tube for a petroleum well, wherein the system comprises a centering element and a tool, wherein the tool further comprises: a housing which is rotatable around a center axis of the tool; at least two blade holders each comprising a plurality of blades positioned along the periphery of each blade holder; and guide elements arranged to guide the blade holders between an active position and a passive position, wherein each of the blades is arranged in use to alternatingly contact the tube when the blades are in contact with the tube, the housing is rotating and the blade holders are rotating and in the active position; wherein each blade holder is rotatable around a center axis of the blade holder such that the blades alternatingly contact the tube in use.

28. A method for using a tool for removing a portion of a tube, the method comprising the steps of: lowering the tool into a tube and to a depth at which a portion of the tube should desirably be removed; providing a rotation of the housing around the center axis of the tool; moving the tool in an axial direction in the tube; moving at least one blade holder into an active position so that the plurality of blades engage with the tube in a processing manner; moving the tool at an axial speed such that the plurality of blades penetrate the tube wall and chips are separated from the tube; stopping the rotation of the housing 1, and moving the at least one blade holder into a passive position when a desired length of the tube has been removed.

29. The method in accordance with claim 28, wherein the method further comprises the step of providing a rotation of the blade holders.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0071] In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings, in which:

[0072] FIG. 1 shows, in perspective, the tool positioned in a tube;

[0073] FIG. 2a shows the tool in an active position, seen from the side;

[0074] FIG. 2b shows the tool in the active position, seen from below;

[0075] FIG. 3a shows the tool in a passive position, seen from the side;

[0076] FIG. 3b shows the tool in the passive position, seen from below;

[0077] FIG. 4a shows a blade holder with rotatable blades;

[0078] FIG. 4b shows the blade holder of FIG. 4a from above;

[0079] FIG. 5 shows a blade holder with fixed blades;

[0080] FIG. 6a shows a side view of a cutting tool with angled blades;

[0081] FIG. 6b shows the cutting tool of FIG. 6a in perspective;

[0082] FIG. 7 shows a section of the tool; and

[0083] FIG. 8 shows the tool connected to a tool holder.

DETAILED DESCRIPTION OF THE DRAWINGS

[0084] Reference is made first to FIGS. 1, 2a, 2b, 3a and 3b:

[0085] A tool 1 is mounted on a centring element 80 and shown positioned inside a tube 90 with an internal surface 91. A portion of the tube 90 has been removed in the FIGS. in order to better show the invention.

[0086] The tool 1 comprises a housing 10 which is shown with three cutting tools 20, each comprising a blade holder 21 provided with a plurality of blades 22. Three cutting tools 20 contribute to a self-centring effect of the tool 1 and the necessary stability of the tool 1 during internal processing of the tube 90.

[0087] The housing 10 comprises a cylindrical portion 12 and a rounded end portion 11. The rounded end portion 11 makes the tool 1 have a penetrating effect when the tool 1 is lowered down the tube 90 in the direction R2. The housing 10 comprises a slot 13 arranged to accommodate the cutting tool 20. In an alternative embodiment (not shown), the end portion 11 may have another penetrating shape. In an alternative embodiment (not shown), the end portion 11 may be adapted for being coupled to another tool or element.

[0088] The cylindrical portion 12 may be formed of a tube, rod element or casting. The rounded end portion 11 may be formed of a rod element or casting.

[0089] In FIGS. 1, 2a, 2b, 3a, 3b and 4, the blades 22 are shown as rotatable blades. The rotatable blades 22 are shown positioned axially on a working surface 24 of the blade holder 21. The blades 22 may be fixed blades 22, as shown in FIG. 5. In FIG. 5, the blades 22 are shown positioned radially to the working surface 24. When the tube 90 is to be processed, the tool 1 rotates in the direction ROT as shown in FIG. 1.

[0090] The cutting tool 20 is shown pivotably connected to the housing 10 via a guide arm 30 (FIGS. 4a, 4b and 5) so that the cutting tool 20 can be moved between an active position A, as shown in FIGS. 1, 2a and 2b, and a passive position B, as shown in FIGS. 3a and 3b.

[0091] The housing 1 is rotatable around a centre axis X1. The rotation may be provided by supplying a fluid to the tool 1. The fluid may be mud, for example. In an alternative embodiment not shown, the rotation may be provided by means of an electric motor.

[0092] Each blade holder 21 has an axis of rotation X2 which is slanted relative to the centre axis X1 of the tool, and each blade holder 21 is freely rotatable around its axis of rotation X2. By the axis of rotation X2 being slanted, a rotation of the blade holder 21 around its axis of rotation X2 may be provided when the blades 22 are in contact with the tube 90 and the housing 10 is rotating around its centre axis X1.

[0093] Each of the rotatable blades 22 can rotate freely around its blade axis X3. The blade holder 21 and the rotatable blades 22a may rotate independently of each other. By the blade holder 21 being rotatable, both the rotatable blades 22a and/or the fixed blades 22b that are mounted on the blade holder 21 may alternatingly be in cutting and rotating contact with an internal surface 91 of the tube 90.

[0094] The tool 1 is arranged to be lowered into the tube 90 in a direction R2. When the tool 1 is being lowered into the tube 90, the cutting tools 20 are positioned in the inactive position B, shown in FIGS. 3a and 3b, so that contact between the blades 22 and the tube 90 can be avoided.

[0095] When the tool 1 is in the desired position in the tube 90, the processing of the tube 90 may begin. The tool 1 is set in rotation around its centre axis X1 and moved in the working direction R1. The cutting tools 20 are moved out radially from the passive position B into the active position A so that the blades 22 come into contact with the internal surface 91 of the tube 90 and can subject the tube 90 to chip-separating processing.

[0096] When the tube 90 is being processed, each of the rotatable blades 22 may rotate around the three centre axes X1, X2 and X3, the blades being moved axially along the centre axis X1 at the same time. The effect of this is that the blades 22 can rotate and penetrate the tube wall through 360 degrees around the centre axis X1 in a desired axial length, for example 50 metres.

[0097] By the centre axes X3 of the rotatable blades 22 being slanted relative to the centre axis X1 of the tube and tool, the blades 22 and the blade holder 21 are brought to rotate, so that the blades 22 that are processing the tube 90 will rotate and alternate continuously.

[0098] The cutting tool 20 that is shown in FIGS. 1-4b has sixteen rotatable blades 22. If each blade 22 has a diameter of 20 mm, for example, this gives each blade 22 a cutting edge with a peripheral length of 63 mm. The total cutting-edge length of the cutting tool 20 as shown will then be approximately 1000 mm. The total cutting-edge length 23 of a tool 1 with three cutting tools 20 will then be 3000 mm. Thereby, in this example, the tool 1 may provide a plurality of cutting edges with a total peripheral length of 3000 millimetres.

[0099] An example: A tube 90 has an internal diameter of 340 mm and a wall thickness of 13 mm, corresponding to an area of 144 cm.sup.2. The tube 90 is to be removed in a length of 50 metres, corresponding to a volume of 720 dm.sup.3. With the above example as a starting point, the invention makes 3000 mm of cutting edge available for processing 720 dm.sup.3 of steel (0.72 m.sup.3). By comparison, a prior-art tool with fixed blades will typically only have 100-300 mm of cutting edge available.

[0100] The cutting tool 20 is shown pivotably connected to the housing 10 via a guide element 30, shown as an arm in the figure. The length of the guide element 30 and the diameter of the cutting tool 22 may be adapted to the dimensions of the tube 90. The adjustment between the passive position A and the active position B can be done by using an actuator. The actuator may be a linear actuator.

[0101] FIGS. 4a and 4b show a cutting tool 20 with rotatable blades 22. The rotatable blades 22 can rotate around third centre axes X3. As shown in FIG. 4b, the blade holder 21 is slanted relative to the guide element 30.

[0102] FIG. 5 shows a cutting tool 20 with fixed blades 22b. As shown in FIG. 4b, the blade holder 21 is slanted relative to the guide element 30. The fixed blades 22b are shown with centre axes X3 that are perpendicular to the working planes of the blades 22b. The blades 22b in FIG. 5 are shown with a polygonal surrounding cutting edge consisting of four cutting-edge segments.

[0103] Reference is now made to FIGS. 6a, 6b, 7 and 8.

[0104] FIGS. 6a and 6b show a third embodiment 21c of the blade holder, in which a plurality of rotatable blades 22c are angled at 5 degrees relative to the centre axis X2 of the blade holder 21. In an embodiment not shown, the angle may be larger or smaller than 5 degrees. The blade holder 21c is arranged for perpendicular mounting to a displaceable guide element 30a, the centre axis X2 of the blade holder being arranged perpendicularly to the centre axis X1 of the tool 1, as shown in FIG. 7. As shown in FIG. 7, the displaceable guide element 30a may be arranged to be displaced perpendicularly to the centre axis X1 of the tool. The blades 22c are supported on two sides, there being a cover 25 mounted on a working side of the blades 22c. When the tube 90 (FIG. 1) is to be processed, the tool 1 rotates in the direction ROT as shown in FIG. 8. The blades 22c are circular and provided with surrounding cutting edges which are divided into a plurality of cutting-edge segments 26 separated by axial grooves 27. The blades 22c have working planes P22, the working planes P22 being arranged to process the tube 90 (FIG. 1).

[0105] The blade holder 21b may be displaced radially between the passive position B and the active position A by the guide element 30a sliding in a linear guide 40, shown as an actuator piston. At a first end 41, the linear guide 40 comprises a wedge with guideways 45 engaging with the guide element 30a. When the linear guide 40 is moved in the axial direction R2, the blade holder 21c is moved radially outwards, the blade holder being rotatably attached to the guide element 30a. When the linear guide 40 is moved in the axial direction R1, the blade holder 21c is moved radially inwards. The axial motion of the linear guide 40 is controlled by carrying liquid, for example mud, into a cylinder chamber 42. The pressure in the cylinder chamber 42 compresses a plurality of return springs 43. When the pressure in the cylinder chamber 42 is reduced, by liquid being drained from the cylinder chamber 42, the return springs push the linear guide back in the direction R1.

[0106] A tubular shaft 50 is rotatably connected, at a first end 51, to a drill string via an epicyclic transmission 53. The epicyclic transmission 53 may be arranged to reverse the direction of rotation from the drill string to the tubular shaft 50 to prevent casing from loosening at threaded connections (collars). Further, the epicyclic transmission 53 may change the number of revolutions so that the tubular shaft 51 may, for example, rotate at half the speed relative to the drill string and, at the same time, transmit a momentum twice as large. The tubular shaft 50 is connected, at a second end, to a centre gear 54 which is arranged to transmit a rotation to three drive lines 60 via gears 55 connected to each of the drive lines 60. Each of the drive lines 60 is connected to respective blade holders 21c. The drive lines 60 transmit the forces to the blade holders 21c via worm drives 61. The drive lines 60 may comprise a plurality of universal joints 62 so that the blade holders 21c can be driven regardless of their radial positions. When the tool 1 is operative, the housing 10 rotates around the tubular shaft 50.

[0107] It should be noted that all the above-mentioned embodiments illustrate the invention, but do not limit it, and persons skilled in the art may construct many alternative embodiments without departing from the scope of the attached claims. In the claims, reference numbers in brackets are not to be regarded as restrictive.

[0108] The use of the verb “to comprise” and its different forms does not exclude the presence of elements or steps that are not mentioned in the claims. The indefinite article “a” or “an” before an element does not exclude the presence of several such elements.

[0109] The fact that some features are indicated in mutually different dependent claims does not indicate that a combination of these features cannot be used with advantage.