Magnetic Fishing Tool with Alternative Flow Capability and Method

Abstract

The magnetic fishing tool has an axial flow passage through a valve member and one or more magnets for initial dispersal of debris away from the fish. Once engaged to the fish the flow direction can be altered by moving the valve member to open lateral ports and to close the straight through path so that fluid circulates above the fish to clear debris from ahead of the fish on the trip out of the hole. This can be accomplished with an object landed on a seat in the valve member, which causes it to shift axially to expose the lateral ports. Optionally the valve member can be shifted with flow in which case the flow will continue axially as well as laterally for the retrieval of the fish.

Description

FIELD OF THE INVENTION

The field of the invention is magnetic fishing tools and related methods and more particularly where the flow can be directed down to the fish and then redirected for circulation above the magnet during retrieval of the fish.

BACKGROUND OF THE INVENTION

At times magnetic objects need to be removed from a borehole in a process called fishing. These operations typically involve fluid movement for debris agitation around the object to be retrieved known as the fish. Magnets are used to bring a connection close to the fish with the hope of engaging the fish in a way that will allow it to be pulled out of the hole and retained for the trip up the hole to the surface. Other applications simply use magnets to capture debris loosened by cleaning devices. These designs are illustrated in U.S. Pat. No. 5,348,086; US20130000884; U.S. Pat. Nos. 8,689,877; 6,357,539 (FIG. 7); U.S. Pat. Nos. 6,629,562; 3,905,631 and 4,059,155.

One issue with the prior designs is that they either lacked a circulation path altogether or their circulation path was exclusively downwardly oriented toward the fish. The idea was to disperse debris to facilitate dispersal of debris around the fish to enhance the chance of grabbing the fish for the trip out of the hole. The flow regime was always deployed in a single direction and this allowed the suspended debris to settle back down as the fish removal was attempted. The present invention addresses this shortcoming in the prior design by allowing the flow direction to be changed from the time up to engagement of the fish until the time it is desired to bring out the fish. The flow direction is changed from straight down toward the fish to laterally or uphole orientation to disperse or fluidize debris ahead of the fish to enhance the removal of the fish and minimize the chance of getting the fish stuck on the way out of the hole. To make this happen a flow through valve member is positioned to block lateral or uphole flow until the fish is engaged. Thereafter, the valve member can be activated with higher flow or a dropped object on a seat to shift the valve member and open ports that will direct flow laterally or in an uphole direction to aid the removal process for the fish. These and other aspects of the present invention will be more readily apparent to those skilled in the art from a review of the description of the preferred embodiment and the associated drawings with the understanding that the full scope of the invention is to be determined from the appended claims.

SUMMARY OF THE INVENTION

The magnetic fishing tool has an axial flow passage through a valve member and one or more magnets for initial dispersal of debris away from the fish. Once engaged to the fish the flow direction can be altered by moving the valve member to open lateral ports and to close the straight through path so that fluid circulates above the fish to clear debris from ahead of the fish on the trip out of the hole. This can be accomplished with an object landed on a seat in the valve member, which causes it to shift axially to expose the lateral ports. Optionally the valve member can be shifted with flow in which case the flow will continue axially as well as laterally for the retrieval of the fish.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a section view of the magnetic fishing tool with a protective cover for shipping;

FIG. 2 is an enlarged view of the circle shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIG. 1 shows a fishing tool body 10 having an upper connection thread 12 and a lower end open recess 14 in which resides at least one magnet 16. A passage 18 extends from thread 12 to recess 14. A sleeve 20 has a passage 22 and outer peripheral seals 24 against the body 10 in the passage 18. Flow entering passage 18 continues through passage 22 and out recess 14 past the magnet or magnets 16 when running in the hole toward the fish, not shown, that is to be retrieved. Also shown in FIG. 1 is a protective cover 26 with handles 28 that is removed before the body 10 is run in the hole on a variety of conveyances that are not shown. Such conveyances can be rigid or coiled tubing, for example, so that pressurized fluid can be delivered through passages 18 and 22 on the way to the fish.

During running in the lateral ports 30, three of which are visible in the section view of FIG. 1, are closed as they are located between seal assemblies 32 and 34. While the ports 30 are shown at 90 degrees to the axis of body 10 the ports can be tilted in an uphole direction or they can be tangentially located with respect to the outer surface of the body 10 or they can also be skewed relative to the axis of body 10 in a manner that creates a swirl pattern in an uphole direction to push away debris as the fish that is not shown is brought out of the hole. The orientation of the ports 30 can have one or more of the attributes described above. They can be in a single row or multiple rows. They can be equally spaced in multiple orientations or randomly spaced. They can be all the same size and shape or different shapes or sizes. For running in the seat 36 is in the FIG. 1 position and can be optionally retained in that position by a breakable member such as a shear pin or ring, for example. Optionally, the seat 36 can be made of a material that disintegrates or otherwise goes away with exposure to well conditions or the passage of time to allow running in with ports 30 closed and passage 18 open and at a later time after the fish is attached the ports 30 can open with flow through passage 18 continuing. Preferably, the seat 36, which serves as a flow diverter, has a landing location 38 for a similarly shaped object such as plug 40 shown in dashed lines. It further has a through passage 23 to communicate with passage 22 when plug 40 is not present. With plug 40 in position the passage 22 is isolated and the ports 30 are opened as the seat 36 shifts in tandem with the plug 40 to open the ports 30. If there is a retainer, shown schematically as 42, it will be defeated with the force of fluid pressure on object 40. Optionally, object 40 can disintegrate with time or exposure to well conditions as well as seat 36 if it is desired to reopen passage 22 on the way out of the hole with the fish that is not shown.

FIG. 2 illustrates a removable cap 42 used for protection when tripping in the hole to not expose a thread 44 that can be used in a different trip with cap 42 removed to mount various tools such as cut lip guide, washover shoe, muleshoe, wall hook guide and etc. With cap 42 in place the fishing is done with only the magnets 16. As mentioned before the protective cover 26 would also come off before the body 10 is run into the borehole.

Those skilled in the art will appreciate that the magnetic fishing tool described above has the capability to switch flow direction through its body so that going in the hole the flow is directed downwardly toward the fish and after a grip is obtained the flow orientation can be reoriented to circulate out above the fish either laterally or in an uphole direction to keep debris fluidized ahead of the fish as the fish is brought out of the hole. It is preferable to cut off flow going straight through the tool with the fish engaged as that reduces the chances of the fish becoming dislodged from the tool on the way out of the hole. The magnets help with alignment of the body with the fish so that a grip can be obtained by a tool connected near the magnets or by a thread on the magnetic fishing tool engaging the fish directly. The change of flow configuration can also be accomplished in a variety of ways such as a pressure actuated indexing device that is capable of opening ports 30 and closing them multiple times if it is necessary to change the direction of the flow exiting body 10 more than once. The flow diverter device can move axially or turn or both to redirect flow from axial to lateral or in an uphole direction. It can be moved with a shift tool or without well intervention. Different types of magnets can be used although permanent magnets are preferred for simplicity and to avoid the provision of power to tool.

The above description is illustrative of the preferred embodiment and many modifications may be made by those skilled in the art without departing from the invention whose scope is to be determined from the literal and equivalent scope of the claims below:

Claims

1. A magnetic fishing tool for downhole use, comprising:

a body comprising a through passage and at least one wall port;

at least one magnet mounted adjacent to a lower end of said body;

a flow diverter in said passage for selectively directing flow between a first direction toward said magnet and a second direction out said at least on wall port.

2. The tool of claim 1, wherein:

said flow diverter responsive to pressure differential.

3. The tool of claim 1, wherein:

said through passage passing through said at least one magnet.

4. The tool of claim 1, wherein:

said at least one wall port comprises multiple wall ports.

5. The tool of claim 4, wherein:

said wall ports oriented laterally to a longitudinal axis of said body or toward an uphole end of said body.

6. The tool of claim 4, wherein:

said wall ports oriented to create a swirling fluid motion in a direction toward an uphole end of said body.

7. The tool of claim 4, wherein:

said ports are identical and equally spaced.

8. The tool of claim 4, wherein:

said ports are different and randomly spaced.

9. The tool of claim 1, wherein:

said flow diverter selectively retained in said passage against axial movement.

10. The tool of claim 1, wherein:

said flow diverter formed to accept an object to close off said passage to allow pressure buildup for opening said at least one port.

11. The tool of claim 1, wherein:

said flow diverter capable of alternating flow between said first and second direction more than once.

12. The tool of claim 1, wherein:

said at least one magnet comprising a permanent magnet.

13. The tool of claim 1, wherein:

said body comprising an exterior thread adjacent a lower end thereof.

14. The tool of claim 1, further comprising:

a removable protective cover for said body for use during shipping.

15. The tool of claim 1, wherein:

at least a portion of said flow diverter disintegrates with exposure to downhole conditions or the passage of time.

16. A fishing method for downhole use, comprising:

providing a through passage in a body and at least one wall port;

locating at least one magnet adjacent to a lower end of said body;

selectively directing flow, with a flow diverter in said passage, between a first direction past said magnet on approach to a fish to be captured and a second direction out said at least on wall port as the fish is brought out of a downhole location.

17. The method of claim 16, wherein:

operating said flow diverter responsive to pressure differential.

18. The method of claim 16, wherein:

locating said through passage through said at least one magnet.

19. The method of claim 16, wherein:

providing multiple wall ports as said at least one wall port.

20. The method of claim 19, wherein:

orienting said wall ports laterally to a longitudinal axis of said body or toward an uphole end of said body.

21. The method of claim 19, wherein:

orienting said wall ports to create a swirling fluid motion in a direction toward an uphole end of said body.

22. The method of claim 19, wherein:

configuring said ports identically and with equal spacing.

23. The method of claim 19, wherein:

configuring said ports differently and with random spacing.

24. The method of claim 16, wherein:

selectively retaining said flow diverter in said passage against axial movement.

25. The method of claim 16, wherein:

forming said flow diverter to accept an object to close off said passage to allow building pressure for opening said at least one port.

26. The method of claim 16, wherein:

alternating flow in said flow diverter between said first and second direction more than once.

27. The method of claim 16, wherein:

providing a permanent magnet as said at least one magnet.

28. The method of claim 16, wherein:

locating an exterior thread adjacent a lower end of said body

29. The method of claim 16, further comprising:

covering said body during shipping with a removable protective cover.

30. The method of claim 16, wherein:

disintegrating at least a portion of said flow diverter with exposure to downhole conditions or the passage of time.