Well Tool Modules for Radial Drilling and Anchoring

Abstract

A drilling module is for radial drilling in a well and an anchoring module is for use in a well tool. The drilling module has a piston for receiving a drill for the radial drilling, and for displacing the drill in a radial direction towards a wall of the well and a cylinder for receiving and guiding the piston. Both the piston and the cylinder are guide-free and of a non-circular shape, at least in a portion, to prevent relative rotation between them. The anchoring module has an extent in the axial direction of the well. The anchoring module includes a displacement device arranged to push against a portion of the wall of the well to press the anchoring module against an opposite portion of the wall of the well. The displacement device is oblong in the axial direction of the anchoring module.

Claims

1. A drilling module for radial drilling in a well, the well being defined by a wall and the well having an extent in an axial direction, the drilling module comprising: a piston for receiving a drill for the radial drilling, and for displacing the drill in a radial direction towards the wall of the well; and a cylinder for receiving and guiding the piston, wherein both the piston and the cylinder are guide-free and of a non-circular shape, at least in a portion, to prevent relative rotation there between.

2. The drilling module according to claim 1, wherein the piston and the cylinder have an oval shape, at least in a portion.

3. The drilling module according to claim 1, wherein the piston and the cylinder have a triangular shape, at least in a portion.

4. The drilling module according to claim 1, wherein the piston is telescopic.

5. The drilling module according to claim 1, wherein the piston is fluid-operated.

6. The drilling module according to claim 1, wherein the drilling module includes a motor arranged to rotate the cylinder housing which, via the piston, rotates the drill.

7. An anchoring module for use in a well tool in a well, the well being defined by a wall and the well having an extent in an axial direction, the anchoring module comprising: in a position of application of the anchoring module, an extent in the axial direction of the well, and a displacement device arranged to push, in a position of application of the displacement device, against a portion of the wall of the well to thereby press the anchoring module against an opposite portion of the wall of the well, wherein the displacement device is oblong in the axial direction of the anchoring module.

8. The anchoring module according to claim 7, wherein the displacement device includes at least one displacement element.

9. The anchoring module according to claim 8, wherein the at least one displacement element is positioned along a common axis which is parallel to the axial direction of the anchoring module.

10. The anchoring module according to claim 7, wherein the displacement device has an axial extent which is orthogonal to an axial direction of the anchoring module.

11. The anchoring module according to claim 8, wherein the displacement element is telescopic in an axial direction of the displacement device.

12. The anchoring module according to claim 7, wherein the displacement device is oval.

13. The anchoring module according to claim 7, wherein the displacement device is fluid-operated.

14. The anchoring module according to claim 7, wherein the anchoring module further has a safety device for releasing the pressure of the anchoring module against the wall of the well.

15. The anchoring module according to claim 14, wherein the safety device includes an accumulator.

16. The anchoring module according to claim 14, wherein the safety device is arranged to withdraw the displacement device from the wall of the well.

17. A well tool comprising a drilling module for radial drilling in a well, the well being defined by a wall and the well having an extent in an axial direction, the drilling module comprising: a piston for receiving a drill for the radial drilling, and for displacing the drill in a radial direction towards the wall of the well; and a cylinder for receiving and guiding the piston, wherein both the piston and the cylinder are guide-free and of a non-circular shape, at least in a portion, to prevent relative rotation there between.

18. The well tool according to claim 17, comprising an anchoring module, which is connected to the drilling module, a displacement device of the anchoring module being placed on the opposite side from the drill of the drilling module in the position of application of the displacement device.

19. A well tool comprising: an anchoring module for use in a well tool in a well, the well being defined by a wall and the well having an extent in an axial direction, the anchoring module comprising: in a position of application of the anchoring module, an extent in the axial direction of the well, and a displacement device arranged to push, in a position of application of the displacement device, against a portion of the wall of the well to thereby press the anchoring module against an opposite portion of the wall of the well, wherein the displacement device is oblong in the axial direction of the anchoring module.

20. The well tool according to claim 19, wherein the well tool comprises: a well-operation device connected to the anchoring module, the well-tool device having an operation zone for carrying out well operations, the operation zone of the well-operation device being positioned opposite to the displacement device of the anchoring module.

21. The well tool according to claim 20, wherein the well-operation device is a drilling module for radial drilling in a well, the well being defined by a wall and the well having an extent in an axial direction, the drilling module comprising: a piston for receiving a drill for the radial drilling, and for displacing the drill in a radial direction towards the wall of the well; and a cylinder for receiving and guiding the piston, wherein both the piston and the cylinder are guide-free and of a non-circular shape, at least in a portion, to prevent relative rotation there between, for radial drilling in a well.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0048] In what follows, an example of a preferred embodiment is described, which is visualized in the accompanying drawings, in which:

[0049] FIG. 1 shows a lateral section of a drilling module for radial drilling, with the drill retracted;

[0050] FIG. 2 shows a lateral section of the drilling module with the drill retracted, the piston and the cylinder having been rotated 90 degrees in relation to in FIG. 1;

[0051] FIG. 3 shows a lateral section of the drilling module in FIG. 2, but with the drill pushed out;

[0052] FIG. 4 shows an exemplary embodiment of a piston according to the invention;

[0053] FIG. 5 shows a longitudinal section of an anchoring module in a well, the anchoring module being in a passive position;

[0054] FIG. 6 shows the anchoring module of FIG. 5, but where a displacement element is in contact with the wall of the well;

[0055] FIG. 7a shows a cross section of a well with an anchoring module in which both the displacement element and the anchoring module are in contact with the wall of the well, on the opposite side from each other;

[0056] FIG. 7b shows a longitudinal section along the line A-A indicated in FIG. 7a;

[0057] FIG. 8 shows a longitudinal section corresponding to FIG. 7b, but in which the safety device has been activated and the displacement element retracted;

[0058] FIG. 9 shows a partially cut-away perspective view of an anchoring module in a casing; and

[0059] FIG. 10 shows a well tool including an anchoring module and a drilling module for radial drilling.

DETAILED DESCRIPTION OF THE DRAWINGS

[0060] Like or corresponding elements are indicated by the same reference numerals in the figures.

[0061] Specifications of position and orientation, such as upper, lower, above, below, vertical and horizontal refer to the position shown in the figures.

[0062] FIG. 1 shows a longitudinal section of a drilling module 1 in a passive position. In the drilling module 1 is shown, here, a recess 13 or opening 13 in which a cylinder housing 10 and a cylinder 12 are accommodated. The cylinder housing 10 may also be referred to as a rotary body 10 as it is set into rotation by means of a motor 15 via a system for power and rotation transmission which includes, for example, a shaft 16, necessary ball bearings 17 and two gears 14 forming a bevel-gear drive, one gear 14 of which is attached to the cylinder housing 10, for example with screws. The motor 15 may be an electric motor or a fluid-operated motor, for example. The motor 15 and the system for power and rotation transmission to the cylinder housing 10 of the drilling module 1 will not be described in further detail herein as they are prior art known per se and are considered to be obvious to a person skilled in the art.

[0063] The cylinder 12 is arranged to receive and guide a piston 11, alternatively called a feeding plunger 11. The piston 11 and the cylinder 12 are of a non-circular shape, at least in a portion. In FIG. 1, the section through the piston 11 and cylinder 12 has been made across the smallest diameter, whereas the piston 11 and cylinder 12 of FIG. 2 have been rotated 90 degrees in relation to in FIG. 1. Thus, the non-circular shape, oval in this case, of the piston 11 and cylinder 12 appears. The shape of the piston 11 is shown best in FIG. 4. The piston 11 is further arranged to receive a drill 3. In both FIG. 1 and FIG. 2, the piston 11 is shown fully retracted into the cylinder 12. During drilling, the piston 11, which is shown here as hydraulically operated, will be carried upwards in the cylinder 12, accordingly in a radial direction out towards a well wall 21 (shown in FIG. 10). The entrance and the exit for hydraulic oil are at the bottom of the cylinder housing 10, but are not shown in the figures as the hydraulic operation of a piston in a cylinder is considered to be technically obvious. The piston 11 and the cylinder 12 are formed in such a way that the piston 11 cannot rotate in the cylinder 12, for example by a first portion 111 of the piston 11 being oval in its circumference and being tightly enclosed by a correspondingly oval shape of the cylinder 12. The rotation of the cylinder housing 10 will thus be transmitted to the piston 11 and through this to the drill 3. The drill 3 is attached to a second portion 112 of the piston 11.

[0064] FIG. 3 shows the drilling module 1 of FIG. 2, but with the piston and thereby the drill 3 at maximum displacement relative to the cylinder 12.

[0065] In FIG. 4 is shown, as mentioned above, a piston 11 with a first portion 111 which is oval. In this embodiment, the piston 11 has a second portion 112 which is circular. The drill 3 (shown in FIGS. 1-3) is received and attached in a recess 113 in the second portion 112 of the piston 11.

[0066] FIG. 5 shows an anchoring module 6 in the well 2, the well 2 possibly comprising a casing 2, and the well 2 being defined by the wall 21. The anchoring module 6 is part of a larger well tool 5 (see FIG. 10). In the exemplary embodiment shown here, the well tool 5 and thereby the anchoring module 6 are run into the well 2, approximately centred in the well 2. It is also possible to run the well tool 5 into the well 2 in contact with the wall 21 of the well. The anchoring module 6 has an axial direction A which is approximately parallel to the longitudinal direction of the well 2. The anchoring module 6 is provided with a displacement device 7, the displacement device 7 being shown here in the form of one displacement element 71 which comprises an outer piston 711, an inner piston 712 and a foot 713. In other embodiments, it is conceivable for the displacement device 7 to include several displacement elements 71. The foot 713 forms the contact surface of the displacement element 71 against the well 2 in the position of application. The inner piston 712 and the outer piston 711 are fluid-operated and activated in such a way that they project from the anchoring module 6 into contact with the well wall 21 and are then pushed further out until the anchoring module 6 achieves close contact with the opposite well wall 21 and is clamped against this.

[0067] In an embodiment with several displacement elements 71, it is further conceivable that the displacement elements 71 may share one or more elements. For example, it is conceivable that several displacement elements 71 may share one foot 713, in order thus to have a larger contact surface against the internal wall 21 of the well 2.

[0068] In the embodiment shown, the displacement device 7 has an axial direction a which is orthogonal to the axial direction A of the anchoring module 6.

[0069] In FIG. 5 is further shown a safety device 8 in the form of an accumulator 81 which includes an accumulator piston 811, a spring 812 and a bleed-off port 813. The accumulator 81 is charged as the outer piston 711 and the inner piston 712 of the displacement element 71 are activated for the first time. Hydraulic oil is forced in under the two pistons 711, 712 until they have been pushed out all the way, and hydraulic oil then runs on through a hydraulic inlet line 814 of the accumulator 81, so that the accumulator piston 811 is forced back. The energy is stored by the spring 812 being tensioned. A check valve (not shown) in the hydraulic inlet line 814 of the accumulator 81 prevents the accumulator 81 from discharging. The two pistons 711, 712 are provided with seals in a technically obvious manner as known for hydraulic pistons.

[0070] FIG. 6 shows the same anchoring module 6 as FIG. 5, the only difference being that the outer piston 711 and the inner piston 712 are activated so that the foot 713 of the displacement element 71 has been moved into contact with the wall 21 of the well 2 and the anchoring module 6 thus has been displaced in the direction of the opposite wall 21.

[0071] An in- and outlet 72 for a hydraulic line for the extension and retraction of the displacement element 71 has been indicated. When the displacement element 71 of the displacement device 7 is activated, the hydraulic oil will enter through the in- and outlet 72 and press against the bottom side of both the outer piston 711 and the inner piston 712. The pistons 711, 712 are thus displaced outwards in the axial direction a into contact with the well wall 21. Conversely, a surface on the top side of the piston is pressurized to push the piston back. The accumulator pressure works against the pressure with which the pistons 711, 712 are forced outwards. The bleed-off port 813 ensures that a pressure so high that the system locks will not build up in the accumulator 81.

[0072] In FIG. 7a is shown a cross section of the well 2 or the casing 2 in which the well tool 5 including the anchoring module 6 is located. It can be seen from the figure that the displacement device 7 is in its extended position with the foot 713 in contact with the wall 21 of the well 2 and the opposite side of the anchoring module 6 has achieved contact with the wall 21 of the well 2, so that the anchoring module 6 is clamped in the well 2. The line A-A is indicated in the figure and the section A-A is shown in FIG. 7b.

[0073] The fact that, in this exemplary embodiment, there are an outer piston 711 and an inner piston 712 indicates that the displacement element 71 is telescopic. Displacement elements 71 with further possibilities of extension through more telescopic links are conceivable in the same way as a displacement device 7 which is not telescopic is conceivable.

[0074] FIG. 8 shows the situation after the displacement element 71 has been withdrawn by means of the safety device 8, shown here as an accumulator 81. When the safety device 8 is activated, the spring 812 is released, so that the accumulator piston 811 forces the hydraulic oil back through the hydraulic line 814 of the accumulator 81 and onto a surface (not shown) above the seals of the outer piston 711 and the inner piston 712, respectively, so that the two pistons 711, 712 are pushed back, into the anchoring module 6. The displacement device 7 is deactivated, that is to say withdrawn from the wall 21 of the well 2. Now, the anchoring module 6 and thereby the well tool 5 of which the anchoring module 6 forms part, are not clamped any longer, and can be pulled out if desired.

[0075] In FIG. 9, the anchoring module 6 is shown in perspective in a partially cut-away casing 2. The displacement device 7 is shown here in the form of a telescopic, oval displacement element 71. The oval shape ensures a best possible power transmission, and to further contribute to stability and power transmission, the contact surface of the foot 713 may be slightly curved, for example adapted to the relevant curvature of the well 2. The foot 713 itself may preferably be formed in tempered steel or another suitable material and maybe with grooves or some other means for increased friction against the well wall 21.

[0076] FIG. 10 shows the anchoring module 6 as it forms part of the well tool 5, the well tool 5 also including a well-operation device 9, shown here in the form of the drilling module 1 for radial drilling. The anchoring module 6 and the well-operation device 9 are preferably placed on the opposite side from each other, so that as the anchoring module 6 pushes the well tool 5 towards the wall 21 of the well 2, the well-operation device 9 will come into contact with the wall 21 and thus achieve its maximum radial reach.

[0077] The drilling module 1 and the anchoring module 6 are preferably positioned in the vicinity of each other, maybe next to each other, in the well tool 5. The drilling module 1 and the anchoring module 6 are further preferably positioned in such a way in the well tool 5 that, in the position of application, the displacement device 7 and the piston 11 project in opposite directions. As the anchoring module 6 pushes the well tool 5 towards the wall 21 of the well 2, the drilling module 1 will come into contact with the wall 21 and thus achieve further axial reach.

[0078] 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 dependent claims. In the claims, reference numbers in brackets are not to be considered restrictive. The use of the verb “to comprise” and its various 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. The invention may be implemented by means of hardware comprising several separate elements and by means of a suitably programmed computer. In apparatus claims that mention several means, several of these means may be included in one and the same element of the hardware. The fact that some features are mentioned in mutually different dependent claims does not indicate that a combination of these features cannot be used with advantage. In the figures, like or corresponding features are indicated by the same reference numbers or markings.