Wireline cleaning tool

Abstract

The present invention relates to a wireline cleaning tool for cleaning at least part of a well, the wireline cleaning tool having a first tool end connectable to a wireline and a second tool end, the wireline cleaning tool comprising an electric motor powered through the wireline, a pump driven by the electric motor, the pump having a pump outlet and a pump inlet, and a collection chamber having at least one chamber inlet, wherein the pump is configured to provide a jet stream, and the second tool end has a tool inlet fluidly connected with the chamber inlet for suction into the chamber of well fluid having fluid elements into the chamber, and the second tool end has a tool outlet fluidly connected with the pump outlet for ejecting the jet stream into the well surrounding the tool. The invention also relates to a downhole tool string comprising the wireline cleaning tool and a driving unit / downhole tractor.

Description

[0001] The present invention relates to a wireline cleaning tool for cleaning at least part of a well, the wireline cleaning tool having a first tool end connectable to a wireline and a second tool end. The invention also relates to a downhole tool string comprising the wireline cleaning tool and a driving unit such as a downhole tractor.

[0002] Some cleaning tools use mechanical cleaning in the form of a drilling or milling head in front of the tool to clean e.g. an inner face of a casing of debris or other solids where a pump provides suction through inlets in the head into a bailer for collecting the released particles, i.e. the debris or other solids, through a filter and out through a tool outlet. These mechanical cleaning tools risk machining into the casing wall, thereby increasing the inner diameter and deteriorating the casing from within. Other tools running on drill pipe or coiled tubing use the pressurised fluid supplied from surface through the drill pipe or coiled tubing to release and clean the inner face of the casing by fluid jetting. These jetting tools do not risk machining into the casing but are not always capable of cleaning sufficiently, nor are they able to collect the released particles in the same run, and thus the particles may be scattered while pulling out of hole and running a bailer in to collect the particles.

[0003] It is an object of the present invention to wholly or partly overcome the above disadvantages and drawbacks of the prior art. More specifically, it is an object to provide an improved cleaning tool able to clean a well in an easy and simple manner while run on wireline.

[0004] The above objects, together with numerous other objects, advantages and features, which will become evident from the below description, are accomplished by a solution in accordance with the present invention by a wireline cleaning tool for cleaning at least part of a well, the wireline cleaning tool having a first tool end connectable to a wireline and a second tool end, the wireline cleaning tool comprising:

[0005] an electric motor powered through the wireline,

[0006] a pump driven by the electric motor, the pump having a pump outlet and a pump inlet, and

[0007] a collection chamber having at least one chamber inlet, wherein the pump is configured to provide a jet stream, and the second tool end has a tool inlet fluidly connected with the chamber inlet for suction into the chamber of well fluid having fluid elements and a tool outlet fluidly connected with the pump outlet for ejecting the jet stream into the well surrounding the tool.

[0008] The tool thus provides a wireline-powered solution combining jetting for cleaning and collection of fluid elements so that elements released by the jetting are collected in the chamber. The jet stream from the pump is therefore used for both suction through the tool inlet and jetting of fluid through the tool outlet.

[0009] Moreover, the wireline cleaning tool may further comprise a fluid channel connecting the pump outlet and the tool outlet.

[0010] A long fluid channel provides the possibility of having a long chamber for collection while jetting.

[0011] Also, the wireline cleaning tool may further comprise a one-way valve, a check valve or a flap valve having a flapper element arranged in connection with the chamber inlet for preventing fluid from escaping through the chamber inlet.

[0012] Furthermore, the wireline cleaning tool may also comprise a filter fluidly connected with a chamber outlet for letting well fluid without the fluid elements pass the filter while the fluid elements are collected in the chamber.

[0013] In addition, the wireline cleaning tool may further comprise a circulation chamber connected with the filter for receiving the well fluid without the fluid elements.

[0014] Moreover, the circulation chamber may have a round interface at an end of the circulation chamber so as to guide the well fluid in an efficient manner in order to minimise the loss of flow velocity of the well fluid.

[0015] Further, the wireline cleaning tool comprises a venturi element having a flow channel connecting a first element end with a second element end, the first element end being arranged to receive the jet stream from the pump outlet, and the second element end being connected to the fluid channel.

[0016] The venturi element provides a suction effect so that well fluid is sucked into the jet stream.

[0017] Moreover, the venturi element may be arranged in the circulation chamber.

[0018] Further, the venturi element may comprise a restriction creating a lower pressure in the circulation chamber.

[0019] Also, the venturi element may be arranged at a distance from the pump outlet.

[0020] By having a distance between the first element end and the pump outlet, well fluid in the circulation chamber is sucked into the jet stream and ejected out of the tool outlet.

[0021] In addition, the fluid channel may extend through the chamber.

[0022] Furthermore, the chamber may be an annular chamber.

[0023] Moreover, the chamber may extend through the fluid channel so that the fluid channel is an annular fluid channel circumferenting the chamber.

[0024] Also, the wireline cleaning tool may further comprise a nozzle in fluid connection with the pump outlet.

[0025] In addition, the wireline cleaning tool may further comprise a diverting unit for diverting the jet stream radially outwards.

[0026] Moreover, the diverting unit may comprise part of the fluid channel and part of a suction channel being in fluid communication with the chamber outlet.

[0027] Also, the pump may be a centrifugal pump.

[0028] In addition, suction through the tool inlet may occur simultaneously with the jetting of fluid through the tool outlet.

[0029] Moreover, the tool outlet and the tool inlet may be arranged at a distance between them that is less than 5 cm, preferably less than 3 cm.

[0030] Furthermore, the tool outlet and the tool inlet may be arranged with a wall thickness between the tool inlet and the tool outlet that is less than 2 cm.

[0031] Also, the tool outlet and the tool inlet may be arranged in a front face of the second tool end.

[0032] By having the tool outlet and the tool inlet close to each other in the front face, the released elements from the jetting are almost entirely collected in the chamber and not partly scattered into the well.

[0033] The wireline cleaning tool mentioned above may also be a cleaning tool having no pump or electric motor, where the first tool end of the cleaning tool is connected to a pipe outlet of a pipe, such as coiled tubing or a drill pipe, and where the cleaning tool has a second tool end, and the cleaning tool comprises a collection chamber having at least one chamber inlet wherein liquid supplied through the pipe provides a jet stream, the second tool end having a tool inlet fluidly connected with the chamber inlet for suction into the chamber of well fluid having fluid elements and a tool outlet fluidly connected with the pipe outlet for ejecting the jet stream into the well surrounding the tool.

[0034] Finally, the invention relates to a downhole tool string comprising the wireline cleaning tool and a driving unit / downhole tractor.

[0035] The invention and its many advantages will be described in more detail below with reference to the accompanying schematic drawings, which for the purpose of illustration show some non-limiting embodiments and in which:

[0036] FIG. 1 shows a wireline cleaning tool seen from a side,

[0037] FIG. 2 is a cross-sectional view of part of the wireline cleaning tool,

[0038] FIG. 3 shows a cross-sectional view of part of another wireline cleaning tool,

[0039] FIG. 4 shows a cross-sectional view A-A of the tool shown in FIG. 3, and

[0040] FIG. 5 shows a cross-sectional view B-B of the tool shown in FIG. 3.

[0041] All the figures are highly schematic and not necessarily to scale, and they show only those parts which are necessary in order to elucidate the invention, other parts being omitted or merely suggested.

[0042] FIG. 1 shows a wireline cleaning tool 1 for cleaning at least part of a well 50 having a casing 20 with an inner face 22 which needs cleaning, e.g. because fluid elements have precipitated on the inner face or on completion components forming part of the casing. The wireline cleaning tool 1 has a first tool end 23 connectable to a wireline 3 and a second tool end 24 facing the bottom of the well 50. The wireline cleaning tool 1 comprises an electric motor 2 powered from surface through the wireline 3, a pump 4 driven by the electric motor, the pump 4 having a pump outlet 5 and a pump inlet 7. Furthermore, the tool 1 comprises a collection chamber 6 for collecting released or freely flowing fluid elements entering through at least one chamber inlet 8. The pump 4 is configured to provide a jet stream. The second tool end 24 has a tool inlet 9 fluidly connected with the chamber inlet 8 for suction into the collection chamber 6 of well fluid having the fluid elements, and the second tool end 24 has a tool outlet 10 fluidly connected with the pump outlet for 5 ejecting the jet stream into the well 50 surrounding the tool 1 in a front 25. The tool 1 thus provides a wireline-powered solution combining jetting for cleaning and collection of fluid elements so that the elements released by the jetting are almost all collected in the collection chamber 6. The tool 1 provides a simple solution which does not result in a very long tool as the jet stream from the pump 4 is used for both suction through the tool inlet 9 into the collection chamber 6 and jetting of fluid through the tool outlet 10.

[0043] As shown in FIG. 2, the wireline cleaning tool 1 further comprises a fluid channel 11 connecting the pump outlet 5 and the tool outlet 10 for guiding the jet stream out through the tool outlet 10. The wireline cleaning tool 1 also comprises a one-way valve 12, such as a check valve or a flap valve 12a having a flapper element 26 arranged in connection with the chamber inlet 8 for preventing fluid from escaping through the chamber inlet 8. The wireline cleaning tool 1 further comprises a filter 14 fluidly connected with a chamber outlet 15 for letting well fluid without the fluid elements pass the filter 14 while the fluid elements are collected in the chamber 6. In another embodiment, the filter 14 may be arranged in the collection chamber 6 fluidly between the chamber inlet 8 and the chamber outlet 15. The wireline cleaning tool 1 moreover comprises a circulation chamber 16 connected with the filter 14 or the collection chamber 6 if the filter 14 is arranged in the collection chamber 6 (as illustrated in FIG. 3), and the circulation chamber 16 is configured to receive the well fluid without the fluid elements and to circulate the well fluid into the fluid channel 11. A venturi element 17 having a flow channel 29 connecting a first element end 18 with a second element end 19 is arranged in the circulation chamber 16 for creating a lower pressure in the circulation chamber 16, creating suction of well fluid from the circulation chamber 16. The first element end 18 of the venturi element 17 is arranged to receive the jet stream from the pump outlet 5, and the second element end 19 is connected to the fluid channel 11. The well fluid from the circulation chamber 16 is thus sucked through the filter 14 out of the circulation chamber 16 into the jet stream and led through the fluid channel 11 out through the tool outlet 10 in the front of the tool 1. The venturi element 17 comprises a restriction 27 creating a lower pressure in the circulation chamber 16. The venturi element 17 is arranged at a distance from the pump outlet 5 in order for the well fluid to enter the jet stream. In another embodiment, the pump outlet 5 may be connected directly to the first element end 18 of the venturi element 17 by a tube that has at least one opening for the well fluid to enter into the jet stream. By having a distance between the first element end 18 and the pump outlet 5 or the opening in the tube, well fluid in the circulation chamber 16 is sucked into the jet stream and ejected out of the tool outlet 10.

[0044] As can be seen in FIG. 2, the fluid channel 11 extends through the collection chamber 6, and the collection chamber 6 is an annular chamber. In this way, the jet stream is not diverted and therefore does not lose much of its pressure from the pump 4 to the tool outlet 10.

[0045] In FIG. 3, the wireline cleaning tool 1 further comprises a diverting unit 32 for diverting the jet stream radially outwards as illustrated by dotted lines, while guiding the well fluid from the collection chamber 6 to the first element end 18 of the venturi element 17. Thus, the diverting unit 32 comprises part of the fluid channel 11 and part of a suction channel 31 being in fluid communication with the chamber outlet 15. In FIG. 3, the filter 14 is arranged in the collection chamber 6, forming an annular flow path 34 in the collection chamber 6 so that well fluid with fluid elements flows from the tool inlet 9 into the annular flow path 34 and past the filter 14 so that the fluid elements remain in the collection chamber 6. The well fluid without the fluid elements then flows out of the chamber outlet 15 and further into the suction channels 31, which are also shown in a cross-sectional view in FIG. 4. The diverting unit 32 is shown in a cross-sectional view in FIG. 4, which shows that the jet stream is guided to flow radially outwards through connecting channel sections 11B and into two fluid channels 11. The flow in the connecting channel sections 11B is illustrated by dotted lines in FIG. 3. The cross-sectional view in FIG. 5 shows the fluid channels 11 of FIG. 4 arranged on the outside of the suction channel 31, which is in fluid communication with the chamber outlet 15. The circulation chamber 16 may have a round interface 35 at an end of the circulation chamber 16 facing the pump 4 so as to guide the well fluid from the chamber 16 in an efficient manner in order to minimise the loss of flow velocity of the well fluid when the well fluid changes direction, as illustrated by arrows, before entering the jet stream. Depending on the object in the casing or well to be cleaned, the chosen solution is either the solution shown in FIG. 2 where the jet stream is both centred and decentralised in relation to the front of the tool 1, and the suction is decentralised, or the solution shown in FIG. 3 where the jet stream is decentralised, and the suction is centralised.

[0046] In another embodiment, the collection chamber 6 extends through the fluid channel 11 so that the fluid channel 11 is an annular fluid channel circumferenting the chamber 6. The venturi element 17 then directs the jet stream from a centre of the tool 1 to the fluid channel 11 formed between the tool housing and the chamber 6 arranged in the centre. The wireline cleaning tool 1 further comprises a nozzle 21 in fluid connection with the pump outlet 5 in order to provide the jet stream. The pump 4 is a centrifugal pump or a similar pump.

[0047] The wireline cleaning tool 1 provides suction through the tool inlet 9 simultaneously with the jetting of fluid through the tool outlet 10 as both the jetting out of the tool outlet 10 and the suction in through the tool inlet 9 are provided by the same pump 4. The jet stream from the pump 4 is both directed for jetting and creating the suction of well fluid in through the chamber inlet 8, past the filter 14 through the suction channel 31 and into the circulation chamber 16. The tool outlet 10 and the tool inlet 9 are arranged at a small distance from each other. The distance is less than 5 cm, and preferably less than 3 cm, as shown in FIG. 2. The tool outlet 10 and the tool inlet 9 are arranged with a small wall thickness between them of less than 2 cm. The tool 1 has a round front face 28, and the tool outlet 10 and the tool inlet 9 are arranged in the front face 28 of the second tool end 24. The invention further relates to a downhole tool string 100, shown in FIG. 2, comprising the wireline cleaning tool 1 and a driving unit / downhole tractor (not shown).

[0048] The wireline cleaning tool 1 may also be a cleaning tool 1 having no pump or electric motor, where the first tool end 23 of the cleaning tool 1 is connected to a pipe outlet 5a of a pipe 4a, such as coiled tubing or a drill pipe. The tool 1 is connected to the pipe outlet 5a instead of the pump outlet 5 as shown in FIG. 2. The tool parts disclosed in FIG. 2 are the same as in the wireline cleaning tool 1 so that the cleaning tool 1 run on the pipe comprises the collection chamber 6 having the at least one chamber inlet 8 wherein liquid supplied through the pipe 4a provides a jet stream, and the second tool end 24 has a tool inlet 9 fluidly connected with the chamber inlet 8 for suction into the chamber 6 of well fluid having fluid elements and a tool outlet 10 fluidly connected with the pipe outlet 5a for ejecting the jet stream into the well surrounding the tool 1.

[0049] By “fluid” or “well fluid” is meant any kind of fluid that may be present in oil or gas wells downhole, such as natural gas, oil, oil mud, crude oil, water, etc. By “gas” is meant any kind of gas composition present in a well, completion or open hole, and by “oil” is meant any kind of oil composition, such as crude oil, an oil-containing fluid, etc. Gas, oil and water fluids may thus all comprise other elements or substances than gas, oil and / or water, respectively.

[0050] By “casing” or “well tubular metal structure” is meant any kind of pipe, tubing, tubular, liner, string, etc., used downhole in relation to oil or natural gas production.

[0051] In the event that the tool is not submergible all the way into the casing, a downhole tractor can be used to push the tool all the way into position in the well. The downhole tractor may have projectable arms having wheels, wherein the wheels contact the inner surface of the casing for propelling the tractor and the tool forward in the casing. A downhole tractor is any kind of driving tool capable of pushing or pulling tools in a well downhole, such as a Well Tractor®.

[0052] Although the invention has been described above in connection with preferred embodiments of the invention, it will be evident to a person skilled in the art that several modifications are conceivable without departing from the invention as defined by the following claims.

Claims

1. A wireline cleaning tool for cleaning at least part of a well, the wireline cleaning tool having a first tool end connectable to a wireline and a second tool end, the wireline cleaning tool comprising:an electric motor powered through the wireline,a pump driven by the electric motor, the pump having a pump outlet and a pump inlet, anda collection chamber having at least one chamber inlet,wherein the pump is configured to provide a jet stream, and the second tool end has a tool inlet fluidly connected with the chamber inlet for suction into the chamber of well fluid having fluid elements, and the second tool end has a tool outlet fluidly connected with the pump outlet for ejecting the jet stream into the well surrounding the tool, characterised in that the cleaning tool further comprises a venturi element having a flow channel connecting a first element end with a second element end, the first element end being arranged to receive the jet stream from the pump outlet, and the second element end being connected to the fluid channel.

2. A wireline cleaning tool according to claim 1, further comprising a fluid channel connecting the pump outlet and the tool outlet.

3. A wireline cleaning tool according to claim 1, further comprising a one-way valve, a check valve or a flap valve having a flapper element arranged in connection with the chamber inlet for preventing fluid from escaping through the chamber inlet.

4. A wireline cleaning tool according to claim 1, further comprising a filter fluidly connected with a chamber outlet for letting well fluid without the fluid elements pass the filter while the fluid elements are collected in the collection chamber.

5. A wireline cleaning tool according to claim 4, further comprising a circulation chamber connected with the filter for receiving the well fluid without the fluid elements.

6. A wireline cleaning tool according to claim 1, wherein the venturi element is arranged in the circulation chamber.

7. A wireline cleaning tool according to claim 1, wherein the venturi element is arranged at a distance from the pump outlet.

8. A wireline cleaning tool according to claim 2, wherein fluid channel extends through the chamber.

9. A wireline cleaning tool according to claim 1, further comprising a nozzle in fluid connection with the pump outlet.

10. A wireline cleaning tool according to claim 1, further comprising a diverting unit for diverting the jet stream radially outwards.

11. A wireline cleaning tool according to claim 1, wherein suction through the tool inlet occurs simultaneously with the jetting of fluid through the tool outlet.

12. A wireline cleaning tool according to claim 1, wherein the tool outlet and the tool inlet are arranged at a distance between them that is less than 5 cm, and preferably less than 3 cm.

13. A wireline cleaning tool according to claim 1, wherein the tool outlet and the tool inlet are arranged in a front face of the second tool end.

14. A downhole tool string comprising the wireline cleaning tool according to claim 1 and a driving unit / downhole tractor.

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