CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of United States patent application serial number 16/805,941 , filed on March 2, 2020, and United States patent application serial number 16/883,746, filed on May 26, 2020, both of which are herein incorporated by reference in their entireties.

BACKGROUND OF THE INVENTION Field of the Invention

[0002] The present disclosure relates to wellbore tools. More specifically, the disclosure relates to a debris collection tool utilizing magnets to collect metallic debris in a wellbore.

Description of the Related Art

[0003] Many operations in an oil or gas well often produce a variety of debris in the wellbore. For example, milling operations may produce metallic mill cuttings, which may not be completely removed by simple circulation of fluid in the wellbore. Retrieval tools containing magnets have been used to collect the debris in wellbores. Magnetic retrieval tools typically have magnets disposed on the exterior of the tool. Having the magnets continuously attracting metallic objects is problematic as there are times when the tool needs to be non-attractive to debris, like during run-in. Some tools have electro magnets that can be turned on and off remotely from the surface. These are unreliable and often require a source of power downhole. In any case, having magnets exposed even when not in use increases the chance of damage and malfunction.

[0004] There is a need, therefore, for an improved magnetic retrieval tool for retrieving debris from the wellbore.

SUMMARY OF THE INVENTION

[0005] The present disclosure generally relates to a debris collection tool for use in a wellbore. In one embodiment, the tool includes a cover assembly having a plurality of covers spaced from one another along the length of the assembly creating a gap between adjacent covers. A carrier disposed within the cover assembly is axial movable relative thereto and has a plurality of magnet groups spaced from one another along its length. In an unactuated position of the tool, each of the plurality of magnet groups is under one of the plurality of covers and in an actuated position, each of the plurality of magnets is in a gap between covers. In another embodiment, a method of operating the tool includes running the tool into the wellbore on a string of tubulars to a predetermined depth and thereafter, providing fluid pressure to a piston surface formed on the carrier thereby causing the tool to move from a deactivated position wherein the magnets are covered, to an activated position wherein the magnets are exposed to the wellbore.

[0006] In another embodiment, a debris collection tool includes a mandrel having a longitudinal flowbore therethrough and an inner sleeve disposed around the mandrel. A first array of magnets is arranged on the inner sleeve. A second array of magnets is disposed around the inner sleeve. The debris collection tool further includes an adaptor sleeve concentric with the mandrel and a linkage coupling the adaptor sleeve with the inner sleeve.

[0007] In another embodiment, a debris collection tool includes a mandrel having a longitudinal flowbore therethrough and an inner sleeve disposed around the mandrel. A first array of magnets is arranged on the inner sleeve. The first array of magnets includes a plurality of inner magnets disposed around a circumference of the inner sleeve. The inner sleeve has a longitudinal groove between two adjacent magnets of the first array of magnets. The debris collection tool further includes a second array of magnets disposed around the inner sleeve. The second array of magnets includes an annular arrangement of magnets between a pair of axially spaced end bands and a bridge between two circumferentially adjacent magnets. The bridge is configured to project into the longitudinal groove.

[0008] In another embodiment, a magnet assembly includes first and second annular end bands and an annular arrangement of magnets disposed between the first and second annular end bands. The first and second annular end bands include substantially a non-magnetic material. The magnet assembly further includes a plurality of bridges. Each bridge is disposed between the first and second annular end bands and between circumferentially adjacent magnets of the annular arrangement of magnets. The bridges include substantially a magnetic material.

[0009] In another embodiment, a controller for a wellbore tool includes a first housing defining a first chamber, and a second housing coupled to the first housing and defining a second chamber. The controller further includes a valve block separating the first and second chambers. A piston is axially movable within the first chamber. A sleeve is coupled to the piston, and extends from the first chamber into the second chamber through the valve block. A fastener is coupled to sleeve and coupled to the second housing. The controller further includes a central longitudinal flowbore through the sleeve and the piston. A first bore through the valve block fluidically couples an annulus between the sleeve and the first housing with the second chamber, and a check valve is associated with the first bore. A second bore through the valve block fluidically couples an annulus between the sleeve and the first housing with the second chamber, and a stop valve is associated with the second bore.

BRIEF DESCRIPTION OF THE DRAWINGS

[0010] So that the manner in which the above recited features of the present disclosure can be understood in detail, a more particular description of the disclosure, briefly summarized above, may be had by reference to embodiments, some of which are illustrated in the appended drawings. It is to be noted, however, that the appended drawings illustrate only typical embodiments of this disclosure and are therefore not to be considered limiting of its scope, for the disclosure may admit to other equally effective embodiments.

[0011] Figure 1 is a perspective view of a cover assembly of a debris collection tool.

[0012] Figure 2 is an exploded view of the cover assembly of Figure 1 .

[0013] Figures 3A and 3B are perspective views of a magnet assembly of the debris collection tool. [0014] Figure 4 is a front view of the assembled debris collection tool.

[0015] Figures 5 and 6 are section views of the deactivated debris collection tool taken along lines 5-5 and 6-6 of Figure 4.

[0016] Figure 7 is a section view showing the relationship between the covers and magnets of the debris collection tool in its deactivated position.

[0017] Figure 8 is an enlarged section view showing an upper actuation portion of the debris collection tool.

[0018] Figure 9 is an enlarged section view showing a lower actuation portion of the debris collection tool.

[0019] Figure 10 is a front view of a wavy ring in its natural, wavy state.

[0020] Figure 11 is the enlarged section view of Figure 9 with the wavy washer shown in a flattened state.

[0021] Figure 12 is the enlarged section view of Figure 11 showing the debris collection tool moving to an actuated position.

[0022] Figure 13 is an enlarged section view of Figure 12 showing the debris collection tool in its final activated position.

[0023] Figure 14 is a section view showing an upper portion of the unactuated debris collection tool in a wellbore.

[0024] Figure 15 is a section view showing an upper portion of the actuated debris collection tool in a wellbore.

[0025] Figure 16 is a section view of a reset assembly shown with the debris collection tool in the unactuated position.

[0026] Figure 17 is a section view of the reset assembly shown with the debris collection tool in the actuated position. [0027] Figure 18 is a section view of the reset assembly shown after the debris collection tool has been reset.

[0028] Figure 19 is a perspective view of another embodiment of a debris collection tool.

[0029] Figure 20 is an exploded view of some components of the embodiment of the debris collection tool of Figure 19.

[0030] Figure 21 is a perspective view of one of the components of Figure 20.

[0031] Figure 22 is an exploded view of some components of the embodiment of the debris collection tool of Figure 19.

[0032] Figure 23 is a perspective view of the components of Figure 22 in an assembled configuration.

[0033] Figure 24 is a perspective view of one of the components of Figure 22.

[0034] Figures 25A to 25D present a longitudinal cross-section of the embodiment of the debris collection tool of Figure 19 in an inactive condition.

[0035] Figure 25E is a perspective view showing two components of the embodiment of the debris collection tool of Figure 19.

[0036] Figures 26A to 26D present a longitudinal cross-section of the embodiment of the debris collection tool of Figure 19 in an activated configuration.

[0037] Figures 27A and 27B present a lateral cross-section representation of the embodiment of the debris collection tool of Figure 19 in an inactive configuration.

[0038] Figures 28A and 28B present a lateral cross-section representation of the embodiment of the debris collection tool of Figure 19 in an activated configuration.

[0039] Figure 29 is a longitudinal cross-section of a portion of the embodiment of the debris collection tool of Figure 19 in a wellbore, with the debris collection tool in an inactive configuration. [0040] Figure 30 is a longitudinal cross-section of the portion depicted in Figure 29, with the debris collection tool in an activated configuration.

[0041] Figure 31 shows the embodiment of the debris collection tool of Figure 19 coupled to a controller.

[0042] Figure 32 shows the embodiment of the debris collection tool of Figure 19 coupled to a controller.

[0043] Figure 33 is a longitudinal cross-section of the assembly depicted in Figure 32, showing an upper part of the embodiment of the debris collection tool of Figure 19 coupled to the controller, with the debris collection tool in an inactive configuration.

[0044] Figure 34 shows the assembly depicted in Figure 33 with the debris collection tool in an activated configuration.

[0045] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation.

DETAILED DESCRIPTION

[0046] The present disclosure relates to a debris collection tool for retrieving metallic debris from a wellbore. The debris collection tool may have magnets, and may use magnetic fields to attract metallic debris. The debris collection tool may be switched between an inactive configuration, in which the magnetic fields emanating from the debris collection tool are relatively weak, and an activated configuration, in which the magnetic fields emanating from the debris collection tool are relatively strong.

[0047] The debris collection tool may include components or materials that are deemed to be “magnetic” or “non-magnetic.” A material that is termed “non magnetic” has a low relative magnetic permeability, whereas a material that is termed “magnetic” has a high relative magnetic permeability. Magnetic permeability is a measure of the ability of a material to support the formation of magnetic fields. Relative magnetic permeability is the ratio of the magnetic permeability of the particular material to the magnetic permeability of free space (i.e. a vacuum), and is denoted by the equation: p _r = m / mo where m _G is the relative magnetic permeability of the material, m is the actual magnetic permeability of the material, and mo is the actual magnetic permeability of free space.

[0048] Table 1 provides some example values of relative magnetic permeability for selected materials.

Table 1

Relative Magnetic

Material Permeability (m _G )

Wood 1.00000043

Aluminum 1.000022

Nickel 100 - 600

99.8% pure Iron 5,000 99.95% pure Iron

200,000 annealed in Hydrogen

[0049] Table 1 shows that 99.95% pure iron annealed in hydrogen has a higher relative magnetic permeability than 99.8% pure iron, which has a higher relative magnetic permeability than nickel, which has a higher relative magnetic permeability than aluminum and wood. Thus, as used herein, the terms “magnetic” and “non magnetic” may be considered as relative terms.

[0050] The debris collection tool 500 of the present disclosure is primarily made up of two assemblies: a cover assembly and a magnet assembly. Figure 1 is a perspective view of the cover assembly 100. The assembly is constructed and arranged to cover a magnet assembly 300 (Figure 3A, B) that moves axially within the cover assembly to expose or cover a plurality of magnet groups 310. The cover assembly 100 includes an upper and lower end caps 110 and includes a bore 115 extending the length of the assembly. The assembly also includes a plurality of spaced covers 120 each of which is separated from an adjacent cover by spacer pins 125. Upper and lower end covers 130 are wider than the other covers. Figure 2 is an exploded view of the cover assembly 100 of Figure 1 . Visible in the exploded view are the end caps 110, covers 120, and spacer pins 125 introduced in Figure 1 . Additionally visible are an inner tube 135, a particle shield 140, and a ring assembly 405.

[0051] Figure 3A and 3B are perspective views of the magnet assembly 300. The magnet assembly, in the embodiment shown is installed inside and axially movable within the cover assembly 100 in a manner whereby magnet groups 310 are covered when the tool 500 is in a deactivated position but exposed in an activated position. The assembly 300 includes a carrier 315 having a bore therethrough. Each magnet group consists of magnets disposed radially around the body of the carrier. Each individual magnet 320 is attached to the carrier by a fastener 325. In addition to housing the magnets, the carrier has a piston surface 330 at an upper end and acts as an annular piston to shift the magnet assembly 300 between the two positions of the tool 500. Figure 3B is an enlarged view of a lower end of the carrier 315. As shown, the carrier has a reduced diameter portion 335 at a lower end with a shoulder 340 formed at a transition point between the two outer diameters. The reduced diameter portion and shoulder are integral to shifting the tool 500 as will be explained herein.

[0052] Figure 4 is a front view of the assembled tool 500 showing the covers 120, 130 as well as the spacer pins 125 separating the covers. Figures 5 and 6 are section views of the deactivated tool 500 taken along lines 5-5 and 6-6 of Figure 4. At the center of Figure 5 is bore 115 formed in the inner tube 135 of the cover assembly 100. Surrounding the inner tube and axially movable relative to the inner tube is the carrier 315 and mounted on its outer surface are the magnets 320 attached to the carrier in radial groups 310 with the fasteners 325 also visible in the Figure. Surrounding the carrier 315 and magnet groups 310 is the particle shield 140 with a space provided between the two parts. As will be shown and explained herein, the particle shield 140 is a thin member that functions to prevent magnetically attracted debris from actually coming into contact with the magnets 320. Covering the particle shield is one of the covers 120 with a space between the two parts. Figure 6 is a section view taken through another portion of the deactivated tool 500. The inner tube 135, carrier 315, and particle shield 140 are visible as well as two of the spacer pins 125. The magnets 320 and cover 120 are labeled but not directly visible in the section view of Figure 6.

[0053] Figure 7 is a section view showing the relationship between the covers 120 and magnets 320 of the tool 500 in its deactivated position. Visible is the inner tube 135, carrier 315, magnets 320, fasteners 325, covers 120 and particle shield 140. In the deactivated position, each magnet is underneath a cover preventing its magnetic properties from escaping to the wellbore (not shown) surrounding the tool 500. As will be illustrated and described herein, shifting the tool 500 to the activated position includes moving the carrier with the attached magnets downwards in relation to the covers 120 in order to expose them to debris in the wellbore.

[0054] Figure 8 is an enlarged section view showing an upper actuation portion of the tool 500. As explained, an upper surface 312 of the carrier 315 operates as a piston surface causing the carrier to operate as an annular piston when a predetermined fluid pressure is placed on surface 312. Shown in the Figure is a port 400 creating a fluid path between the bore of the tool 500 and surface 312. As the tool 500 moves to the activated position, the carrier and magnets will move down to a location wherein the magnets are no longer blocked by the covers130, 120.

[0055] Figure 9 is an enlarged section view showing a lower actuation portion of the tool 500. Visible is a lower, reduced diameter portion 335 of carrier 315 having a lower face 317 constructed and arranged to act on a ring assembly 405 in order to initiate the transition of the tool 500 to the activated position. The ring assembly includes a first ring 410 having an inwardly extending shearable arm 415 that is acted upon by lower face 317 and a wavy ring 420 constructed and arranged to flatten and reform in order to compensate and absorb shock from unrelated pressure events in the wellbore that might otherwise actuate the tool 500 at an unwanted time. Figure 10 is a front view of the wavy ring 420 in its natural, wavy state.

[0056] In the deactivated position shown in Figure 9, face 317 is resting on shearable arm 415 and ring 420 retains its natural, wavy shape. Figure 11 is an enlarged section view showing the same parts of the tool 500 as Figure 9. In this view, the carrier 315 acting as an annular piston, has been acted upon at an upper end (not shown) by pressurized fluid and lower face 317 has applied enough pressure on the shearable arm 415 to cause it to flatten the wavy ring 420. In Figure 12, an enlarged view of the same portions of the tool 500, fluid pressure applied to the carrier 315 has increased to the point where the shearable arm 415 of ring 410 has failed and the carrier 315 with its magnet groups 310 is moving downwards to its final, activated position. The downward movement is shown by arrow 600.

[0057] Figure 13 is an enlarged section view showing the same portions of the tool 500 as the previous views, but showing the tool 500 in its final activated position. In this position, the carrier has moved downwards relative to the other portions of the tool 500 until shoulder 340 formed between the different diameters of the carrier has contacted an upper face of first ring 410 preventing additional downward movement.

[0058] Figure 14 is a section view showing an upper portion of the unactuated tool 500 in a wellbore 510 with debris 520 visible in an annular area 525 between the tool 500 and the wellbore walls. As shown, each magnet 320 of each magnet group 310 is blocked by a cover 120, 130. The unactuated position of the tool 500 would be typical during run-in or in the case of multiple operations in the wellbore, at some point prior to a time when collection of debris is needed. For example, in a drilling operation, the tool 500 might remain in its unactuated position until drilling has taken place. In other instances, the tool 500 will be run-in but only actuated after fluid has been circulated in the annulus 525 to stir up debris 520 and make it easier to attract magnetically. Figure 15 is a section view of the same upper portion of the tool 500 shown in Figure 14. Flowever, in Figure 15 the tool 500 is fully actuated and the magnets 320 are “uncovered” with only the particle shield 140 between the magnets and the debris 520 that is being collected.

[0059] In one embodiment, the tool 500 includes a reset assembly 700 permitting the tool 500 to be easily moved to the unactuated state once it has been recovered at the surface of a well. Shifting the tool 500 back to its original position is useful for cleaning the various parts of the tool 500 before it is returned to a facility to be readied for another use.

[0060] Figure 16 is a section view of a reset assembly shown with the tool 500 in the unactuated position. The reset assembly 700 is constructed and arranged to apply pressure to the carrier 315 in order to return it to its original position relative to the cover assembly 100. The assembly 700 includes a spring-loaded reset piston 710 with a spring 720 initially held in a compressed position be two retainers 730. In the embodiment shown, the spring remains compressed throughout the downhole operation of the tool 500.

[0061] Figure 17 is a section view of the reset assembly 700 shown with the tool 500 in the actuated position. As shown, in the actuated position, the carrier 315 has moved downwards relative to the cover assembly 100 and the magnets 320 are exposed to the wellbore where they may attract debris (see Figure 15). In this position the lower surface 317 of the reduced diameter portion 335 of the carrier 315 abuts an upper end 712 of the spring-loaded reset piston 710 which remains anchored in the charged/com pressed position by the retainers 730.

[0062] Figure 18 is a section view of the reset assembly 700 shown after the tool 500 has been reset at the surface of the well. More specifically, retainers 730 have been loosened until they no longer interfere with the movement of the spring loaded reset piston 710 and the piston has moved upwards taking the magnet carrier 315 with it until the carrier is in the original, unactuated position with each magnet 320 blocked by a cover 120. In the position any collected debris can be removed prior to transporting the tool 500.

[0063] In operation, the tool 500 is run into a wellbore on a string of tubulars at such time as there is a need to collect iron-containing-type debris. The tool 500 may be run-in alone or in combination with other tools like a drill bit. A drilling operation may be conducted while the tool 500 is in the wellbore prior to actuating the tool 500. At any time there is a need for collection of debris, the tool 500 can be actuated by providing a predetermined amount of fluid pressure, typically from the surface via port 400 to the upper surface 330 of the carrier 315. Typically, fluid is circulated in the annulus of the wellbore before or at the time the tool 500 is shifted to its actuated position. Once a desired amount of debris is collected, usually determined by circulating over a set period of time, the tool 500 can be removed from the wellbore, the debris discarded, and the tool 500 re-set at the surface for another use.

[0064] Figure 19 is a perspective view of a debris collection tool 1000. The debris collection tool 1000 may include an upper housing 1002. The upper housing 1002 may have an upper centralizer 1004. In some embodiments, the upper centralizer 1004 may move axially and/or rotationally relative to the upper housing 1002. In some embodiments, the upper centralizer 1004 may not move axially or rotationally relative to the upper housing 1002. In some embodiments, the upper centralizer 1004 and the upper housing 1002 have a unitary construction. The upper housing 1002 may be coupled to a bulkhead 1006 of a mandrel 1008 (see Figure 20). The bulkhead 1006 may be coupled to an upper bonnet 1010, which may be coupled to a cover 1012. The cover 1012 may be coupled to a lower bonnet 1014, which may be coupled to a lower housing 1016. The lower housing 1016 may have a lower centralizer 1018. In some embodiments, the lower centralizer 1018 may move axially and/or rotationally relative to the lower housing 1016. In some embodiments, the lower centralizer 1018 may not move axially nor rotationally relative to the lower housing 1016. In some embodiments, the lower centralizer 1018 and the lower housing 1016 have a unitary construction.

[0065] In some embodiments the upper housing 1002 may be omitted. In some embodiments the upper centralizer 1004 may be omitted. In some embodiments the lower housing 1016 may be omitted. In some embodiments, the lower centralizer 1018 may be omitted. The debris collection tool 1000 may be configured to be connected to other tools and/or a workstring at the bulkhead 1006 or, if present, the upper housing 1002. The debris collection tool 1000 may have a central longitudinal flowbore 1020 that continues from an upper end of the upper housing 1002, through the mandrel 1008, and down to a lower end of the lower housing 1016. The debris collection tool 1000 may be configured to be connected to other tools and/or a workstring at the lower bonnet 1014 or, if present, the lower housing 1016. [0066] Figure 20 is an exploded view of some components of the debris collection tool 1000. Figure 22 is an exploded view of some additional components of the debris collection tool 1000. As shown in Figure 20, a mandrel 1008 may include the bulkhead 1006. In some embodiments, the bulkhead 1006 and the mandrel 1008 may be formed as a unitary component. In some embodiments, the bulkhead 1006 and the mandrel 1008 may include multiple parts that are coupled together. The upper bonnet 1010 may encircle the mandrel 1008 in order to be coupled to the bulkhead 1006. An upper shield 1022 may encircle the mandrel 1008 and be coupled to an interior portion of the upper bonnet 1010. A cover 1012 may encircle the mandrel 1008 and be coupled to an interior portion of the upper bonnet 1010. An outer magnet array 1024 may encircle the mandrel 1008 and inside the cover 1012. The lower bonnet 1014 may encircle the mandrel 1008 and be coupled to a lower end of the cover 1012. A lower shield 1026 may encircle the mandrel 1008 and be coupled to an interior portion of the lower bonnet 1014. A floating piston 1028 may encircle the mandrel 1008 and be coupled to an interior portion of the lower bonnet 1014.

[0067] Figure 21 provides a perspective view of an outer magnet assembly 1030 that forms part of the outer magnet array 1024. The outer magnet array 1024 may include one or more outer magnet assembly 1030. The outer magnet assembly 1030 may include an upper end band1032 and a lower end band 1034. The upper end band 1032 and the lower end band 1034 may be annular in shape. In some embodiments, the upper end band 1032 and the lower end band 1034 may be made out of a substantially non-magnetic material. A ring 1036 of outer magnets 1038 may be disposed between the upper end band 1032 and the lower end band 1034 such that each outer magnet 1038 is coupled to the upper end band 1032 and the lower end band 1034. The outer magnets 1038 may be arranged in the ring 1036 such that the poles of each outer magnet 1038 are circumferentially aligned. The outer magnets 1038 may be arranged to form the ring 1036 such that the North pole of one outer magnet 1038 is facing the North pole of a neighboring outer magnet 1038. Similarly, the South pole of one outer magnet 1038 may be facing the South pole of another neighboring outer magnet 1038. [0068] Each pair of circumferentially adjacent outer magnets 1038 of a ring 1036 of outer magnets 1038 may be separated by a bridge 1040. Each outer magnet 1038 may be circumferentially adjacent to a bridge 1040 at the outer magnet’s 1038 North pole and another bridge 1040 at the outer magnet’s 1038 South pole. Hence the ring 1036 of outer magnets 1038 may include a circumferentially aligned sequence of components in which the components form an alternating sequence of outer magnet 1038, bridge 1040, outer magnet 1038, bridge 1040, and so on. Each bridge 1040 may be formed from a magnetic material, such as a grade of steel that has a relatively high relative magnetic permeability. In some embodiments, one or more bridge 1040 may be sized to extend radially inwardly of the ring 1036 of outer magnets 1038.

[0069] Successive rings 1036 of outer magnets 1038 may be axially aligned to form the outer magnet array 1024. Each outer magnet 1038 within a ring 1036 of outer magnets 1038 may be axially aligned with a corresponding outer magnet 1038 of an adjacent ring 1036 of outer magnets 1038. Hence, the outer magnets 1038 may be aligned in rows in addition to being aligned circumferentially. Additionally, each bridge 1040 within a ring 1036 of outer magnets 1038 may be axially aligned with a corresponding bridge 1040 of an adjacent ring 1036 of outer magnets 1038. Hence, the bridges 1040 may be aligned in rows in addition to being aligned circumferentially.

[0070] Each outer magnet 1038 may include a magnetic material. Some example magnetic materials may include, without limitation, ceramic ferrite, neodymium iron boron, samarium cobalt, and aluminum nickel cobalt. The magnetic material may be encased in a non-magnetic material, such as stainless steel, for the physical and chemical protection of the magnetic material.

[0071] Figure 22 is an exploded view of some components of the debris collection tool 1000 that are additional to the components shown in Figure 20. Figure 23 is a perspective view of the components of Figure 22 as assembled according to one embodiment. The debris collection tool 1000 may have an inner sleeve 1042 coupled to an adaptor sleeve 1044 by a linkage 1046. The inner sleeve 1042 may encircle the mandrel 1008, and may have an inner magnet array 1048. The inner magnet array 1048 may be mounted on an outer surface of the inner sleeve 1042. The inner sleeve 1042 may have one or more aperture 1050 that is sized to accept a key 1052 of the linkage 1046. The linkage 1046 may include one or more key 1052, and each key 1052 may be coupled to an elongate member 1054, such as a rod, a strip, a wire, or a tube. The elongate member 1054 may be coupled to a yoke 1056. In some embodiments, one end of the elongate member 1054 may be coupled to a key 1052 and the other end of the elongate member 1054 may be coupled to the yoke 1056. In some embodiments that include multiple elongate members 1054, the multiple elongate members 1054 may be coupled to a single yoke 1056. In some embodiments, the yoke 1056 may be a unitary member. In some embodiments, the yoke 1056 may include multiple parts coupled together. The yoke 1056 may be coupled to an outer surface of the adaptor sleeve 1044. In some embodiments, the coupling between the yoke 1056 and the adaptor sleeve 1044 may include one or more fastener 1058, such as a set screw, a snap ring, a latch, a locking dog, etc. Because of the one or more fastener 1058, the yoke 1056 may have limited scope for axial movement relative to the adaptor sleeve 1044. In some embodiments, the yoke 1056 may be coupled to the adaptor sleeve 1044 such that the yoke 1056 and the adaptor sleeve 1044 may rotate independently of, and relative to, one another.

[0072] In some embodiments, the adaptor sleeve 1044 may be coupled to an adaptor assembly 1060. In some embodiments, the adaptor assembly 1060 may be omitted. In some embodiments, the adaptor assembly 1060 may be configured to couple the adaptor sleeve 1044 to a tool positioned close to the debris collection tool 1000. The tool positioned close to the debris collection tool 1000 may be a controller, such as any of the controllers 1106 depicted in Figures 31 and 32. In some embodiments, a tool, such as a controller, may be positioned close to the debris collection tool 1000, and may be coupled to the adaptor sleeve 1044 without an intermediate adaptor assembly 1060. In some embodiments, the adaptor assembly 1060 may include a single component. In some embodiments, the adaptor assembly 1060 may include multiple components. [0073] As illustrated in Figure 22, the adaptor assembly 1060 may include an adaptor piston 1062 having an adaptor skirt 1064. The adaptor skirt 1064 may be generally cylindrical, and may be sized to fit inside the adaptor sleeve 1044. The adaptor sleeve 1044 may be coupled to the adaptor skirt 1064, and retained in position using a fastener 1066, such as a set screw, a snap ring, a latch, a locking dog, etc. In some embodiments, a longitudinal position of the adaptor sleeve 1044 on the adaptor skirt 1064 may be adjusted. In some embodiments, the longitudinal position of the adaptor sleeve 1044 on the adaptor skirt 1064 may be adjusted by merely sliding the adaptor sleeve 1044 to a desired position. In some embodiments, the longitudinal position of the adaptor sleeve 1044 on the adaptor skirt 1064 may be adjusted by altering a threaded engagement between the adaptor sleeve 1044 and the adaptor skirt 1064. In some embodiments, the adaptor assembly 1060 may include an adaptor extension 1068 coupled to the adaptor piston 1062. The adaptor extension 1068 may include one or more port 1070. The adaptor extension 1068 may include a debris filter 1072 associated with the one or more port 1070.

[0074] Figure 24 is a perspective view of a portion of the inner magnet array 1048 mounted on an outer surface of the inner sleeve 1042. The inner sleeve 1042 may be generally cylindrical and having inner and outer surfaces. The outer surface may have one or more longitudinal groove 1074. An array 1048 of inner magnets 1076 may be disposed on the outer surface of the inner sleeve 1042. The inner magnets 1076 may be arranged such that the inner magnets 1076 may be axially aligned in rows. The inner magnets 1076 may be arranged such that the inner magnets 1076 may be circumferentially aligned. Thus, each group of circumferentially aligned inner magnets 1076 forms a ring 1078 of inner magnets 1076. The inner magnets 1076 may be arranged such that each pair of circumferentially adjacent inner magnets 1076 may be separated by a longitudinal groove 1074. In embodiments in which the inner magnets 1076 are axially aligned and circumferentially aligned, the inner magnets 1076 may be arranged into axially aligned rings of inner magnets 1076. For reference with later figures, the ring 1078 of inner magnets 1076 closest to a lower end of the inner sleeve 1042 may be considered as a first ring 1078 of inner magnets 1076. Similarly, the ring 1078 of inner magnets 1076 next to the first ring 1078 of inner magnets 1076 may be considered as a second ring 1078 of inner magnets 1076.

[0075] The inner magnets 1076 may be arranged such that the poles of each inner magnet 1076 are aligned with a circumference of the corresponding ring 1078 of inner magnets 1076 to which each magnet belongs. The inner magnets 1076 may be arranged within each ring 1078 such that the North pole of one inner magnet 1076 is facing the North pole of a neighboring inner magnet 1076. Similarly, the South pole of one inner magnet 1076 may be facing the South pole of another neighboring inner magnet 1076.

[0076] Each inner magnet 1076 may include a magnetic material. Some example magnetic materials may include, without limitation, ceramic ferrite, neodymium iron boron, samarium cobalt, and aluminum nickel cobalt. The magnetic material may be encased in a non-magnetic material, such as stainless steel, for the physical and chemical protection of the magnetic material.

[0077] Figures 25A to 25D provide a longitudinal cross-sectional view of an embodiment of the debris collection tool 1000 as assembled in the inactive configuration. As shown in Figures 25A and 25B, an upper housing 1002 may have an upper centralizer 1004, and may be coupled to a bulkhead 1006 of a mandrel 1008. An adaptor assembly 1060 may be disposed inside central longitudinal flowbore 1020 of the debris collection tool 1000 through the upper housing 1002 and the mandrel 1008. The adaptor assembly 1060 may include an adaptor extension 1068 coupled to an adaptor piston 1062. The adaptor piston 1062 may be coupled to an adaptor skirt 1064. In some embodiments, the adaptor piston 1062 and the adaptor skirt 1064 may be formed as a unitary component. In some embodiments, the adaptor extension 1068 and the adaptor piston 1062 may be formed as a unitary component. In some embodiments, the adaptor extension 1068, adaptor piston 1062, and the adaptor skirt 1064 together may be formed as a unitary component.

[0078] The adaptor piston 1062 may have one or more seal 1081 that contacts an inner wall 1082 of the upper housing 1002. The upper housing 1002 and/or the upper centralizer 1004 may have one or more port 1084 that fluidically couples an interior portion 1086 of the upper housing 1002 with an exterior of the upper housing 1002. The adaptor piston 1062 may be positioned below the port 1084. Thus, the adaptor piston 1062 may separate the interior portion 1086 of the upper housing that has a direct fluidic connection with an exterior of the upper housing 1002 from an activation chamber 1088 that does not have a direct fluidic connection with an exterior of the upper housing 1002.

[0079] Still with Figures 25A and 25B, in Figure 25A an adaptor sleeve 1044 is shown coupled to the adaptor skirt 1064 of the adaptor assembly 1060 by a threaded connection 1090 that allows for adjustment of the relative axial positioning of the adaptor sleeve 1044 and the adaptor skirt 1064. A fastener 1066 that secures the adaptor sleeve 1044 to the adaptor skirt 1064 after adjustment of their relative axial position is shown in Figure 25B. The adaptor sleeve 1044 and adaptor skirt 1064 may extend into the central longitudinal flowbore 1020 of the debris collection tool 1000 at the bulkhead 1006 of the mandrel 1008.

[0080] A yoke 1056 of a linkage 1046 assembly is shown coupled to the adaptor sleeve 1044, and situated in the activation chamber 1088 of the upper housing 1002. In some embodiments, as shown in Figure 25A, the yoke 1056 may be retained by one or more fastener 1058. The yoke 1056 is shown coupled to elongate members 1054 that extend through secondary bores 1092 of the bulkhead 1006. One or more seals 1080 between each elongate member 1054 and each corresponding secondary bore 1092 inhibits fluid communication through the secondary bores 1092 into, and out of, the activation chamber 1088. As shown in Figure 25B, each elongate member 1054 is coupled to a key 1052 located in a slot 1094 formed in the mandrel 1008. Each key 1052 is shown coupled to an inner sleeve 1042 by projecting into an aperture 1050.

[0081] In Figure 25B, an upper bonnet 1010 is shown coupled to the bulkhead 1006 and extending over the slots 1094 of the mandrel 1008 and an upper portion of the inner sleeve 1042. The upper bonnet 1010 may be constructed out of a non magnetic material, such as a stainless steel. Transitioning from Figure 25B to Figure 25C, an upper shield 1022 is shown within a lower portion of the upper bonnet 1010. In some embodiments, the upper shield 1022 may be omitted. When present, the upper shield 1022 may be constructed out of a magnetic material, such as a magnetic grade of steel. In some embodiments, the upper shield 1022 may be sized to have a length corresponding to a length of a ring 1078 of inner magnets 1076. In some embodiments, the upper shield 1022 may be sized to have a length that is greater than a length of a ring 1078 of inner magnets 1076. An annular gap between an inner surface of the upper shield 1022 and an outer surface of the inner sleeve 1042 may be sized such that the annular gap may accommodate a ring 1078 of inner magnets 1076. When a ring 1078 of inner magnets 1076 is radially aligned with the upper shield 1022, the upper shield 1022 may inhibit the transmission of a magnetic field from the ring 1078 of inner magnets 1076 through the upper bonnet 1010. Thus, magnetic debris will not be prone to accumulate around the upper bonnet 1010, thereby mitigating a risk of the debris collection tool 1000 becoming stuck in a wellbore due to debris accumulation around the upper bonnet 1010.

[0082] As shown in Figure 25C, a cover 1012 extends from the upper bonnet 1010 to a lower bonnet 1014. The cover 1012 may be constructed out of a non-magnetic material, such as a stainless steel. In some embodiments, an outer diameter of the cover 1012 may be less than an outer diameter of the upper bonnet 1010 and less than an outer diameter of the lower bonnet 1014. A lower end of the upper bonnet 1010, an upper end of the lower bonnet 1014, and the cover 1012 may define a debris collection zone 1096. The debris collection zone 1096 may thus be recessed with respect to the upper bonnet 1010 and the lower bonnet 1014. Such recessing of the debris collection zone 1096 enables debris to be accumulated on the cover 1012 and mitigates a risk of the debris being washed off due to fluid flow around the exterior of the debris collection tool 1000. Such recessing of the debris collection zone 1096 also mitigates a risk of the debris collection tool 1000 becoming stuck in a wellbore due to debris accumulation around the cover 1012.

[0083] The lower bonnet 1014 may be constructed out of a non-magnetic material, such as a stainless steel. A lower shield 1026 is shown within an upper portion of the lower bonnet 1014. In some embodiments, the lower shield 1026 may be omitted. When present, the lower shield 1026 may be constructed out of a magnetic material, such as a magnetic grade of steel. In some embodiments, the lower shield 1026 may be sized to have a length corresponding to a length of a ring 1078 of inner magnets 1076. In some embodiments, the lower shield 1026 may be sized to have a length that is greater than a length of a ring 1078 of inner magnets 1076. An annular gap between an inner surface of the lower shield 1026 and an outer surface of the inner sleeve 1042 may be sized such that the annular gap may accommodate a ring 1078 of inner magnets 1076. When a ring 1078 of inner magnets 1076 is radially aligned with the lower shield 1026, the lower shield 1026 may inhibit the transmission of a magnetic field from the ring 1078 of inner magnets 1076 through the lower bonnet 1014. Thus, magnetic debris will not be prone to accumulate around the lower bonnet 1014, thereby mitigating a risk of the debris collection tool 1000 becoming stuck in a wellbore due to debris accumulation around the lower bonnet 1014.

[0084] As shown in Figure 25C, within the cover 1012, and extending from the upper bonnet 1010 to the lower bonnet 1014 there may be an outer magnet array 1024 having one or more ring 1036 of outer magnets 1038. In embodiments in which the outer magnet array 1024 includes more than one ring 1036 of outer magnets 1038, the rings 1036 of outer magnets 1038 may be longitudinally stacked between the upper bonnet 1010 and the lower bonnet 1014. The ring 1036 of outer magnets 1038 adjacent to the lower shield 1026 may be considered as a first ring 1036 of outer magnets 1038. Similarly, the ring 1036 of outer magnets 1038 next to the first ring 1036 of outer magnets 1038 may be considered as a second ring 1036 of outer magnets 1038. Figure 25C illustrates the inner sleeve 1042 extending over the mandrel 1008, through the cover 1012 and the outer magnet array 1024, and into an upper portion of the lower bonnet 1014. An inner magnet array 1048 on the inner sleeve 1042 is shown positioned within the outer magnet array 1024.

[0085] In some embodiments, a first ring 1078 of inner magnets 1076 may be positioned within the lower shield 1026. In some embodiments, the inner magnet array 1048 may have one ring 1078 of inner magnets 1076 additional to the number of rings 1036 of outer magnets 1038 of the outer magnet array 1024. Flence, a debris collection tool 1000 may include n rings 1036 of outer magnets 1038 and n+1 rings 1078 of inner magnets 1076. In some embodiments, each outer magnet 1038 of the outer magnet array 1024 may be adjacent to, and radially aligned with, a corresponding inner magnet 1076 of the inner magnet array 1048. Thus, each outer magnet 1038 of a first ring 1036 of outer magnets 1038 may be radially adjacent to a corresponding inner magnet 1076 of a second ring 1078 of inner magnets 1076, and so on, such that each outer magnet 1038 of the last (n ^th ) ring 1036 of outer magnets 1038 may be radially adjacent to a corresponding inner magnet 1076 of the last (n+1 ^th ) ring 1078 of inner magnets 1076.

[0086] Figure 25E shows a cut-away perspective view of a ring 1036 of outer magnets 1038 positioned over a ring 1078 of inner magnets 1076. For clarity, only a single ring 1036 of outer magnets 1038 is depicted. Each outer magnet 1038 may be radially adjacent to, and radially aligned with, a corresponding inner magnet 1076. In some embodiments, as illustrated, a radially inward portion of each bridge 1040 of the ring 1036 of outer magnets 1038 may be located in a corresponding longitudinal groove 1074 of the inner sleeve 1042. Therefore, as the inner sleeve 1042 and inner magnet array 1048 moves axially with respect to the outer magnet array 1024, the interaction between each bridge 1040 and the corresponding longitudinal groove 1074 maintains the alignment between individual rows of inner magnets 1076 and corresponding individual rows of outer magnets 1038. In some embodiments, the interaction between each bridge 1040 and a floor 1098 of each corresponding longitudinal groove 1074 may maintain a separation between each outer magnet 1038 and each corresponding radially adjacent inner magnet 1076.

[0087] Returning to Figure 25C, the mandrel 1008 extends through the upper bonnet 1010, through the inner sleeve 1042, and through the lower bonnet 1014. A floating piston 1028 may be contained within an annular space between the lower bonnet 1014 and the mandrel 1008. Seals 1083, 1085 may inhibit the passage of fluid past the floating piston 1028. A sealed compartment may be defined by the annular space between an outer surface of the mandrel 1008 and the inner surfaces of the upper housing 1002, the upper bonnet 1010, the cover 1012, and the lower bonnet 1014; the sealed compartment being bounded at an upper end by the seals 1080 between the elongate members 1054 and the secondary bores of the bulkhead 1006, and at a lower end by the floating piston 1028. The sealed compartment may contain a clean fluid, such as a hydraulic oil, so as to facilitate the movement of the inner sleeve 1042 during operation. During assembly of the debris collection tool 1000, the clean fluid may be introduced into the sealed compartment through one or more filling port 1100 in the upper bonnet 1010 and/or the lower bonnet 1014. Additionally, a filling port 1100 may be use to evacuate air from the sealed compartment while the clean fluid is introduced into the sealed compartment through another filling port 1100.

[0088] The annular space between the lower bonnet 1014 and the mandrel 1008 may be exposed to a pressure external to the debris collection tool 1000 through port 1102. The floating piston 1028 may move within the annular space between the lower bonnet 1014 and the mandrel 1008 in order to balance a pressure within the sealed compartment with a pressure external to the debris collection tool 1000. Further, in Figure 25D, the lower bonnet 1014 may be coupled to a lower housing 1016. The mandrel 1008 may be coupled to the lower housing 1016. The lower housing 1016 may have a lower centralizer 1018.

[0089] Figures 26A to 26D show the debris collection tool 1000 of Figures 25A to 25D in the activated configuration. The debris collection tool 1000 may be switched from the inactive to the activated configurations by the application of pressure in the central longitudinal flowbore 1020 below any present adaptor assembly 1060. This may be achieved, for example, by applying pump pressure to a fluid within a workstring to which the debris collection tool 1000 may be coupled.

[0090] With reference to Figures 26A and 26B, pressure inside the central longitudinal flowbore 1020 may be communicated between the adaptor sleeve 1044 and the adaptor skirt 1064, and/or between the adaptor skirt 1064 and the bulkhead 1006, to the activation chamber 1088. Because of the seals between the elongate member(s) 1054 and the secondary bore(s) of the bulkhead 1006, the pressure in the activation chamber 1088 may not be communicated through the secondary bore(s) of the bulkhead 1006. Pressure in the activation chamber 1088 acts on one side of the adaptor piston 1062. Pressure external to the debris collection tool 1000, communicated through the port(s) 1084 acts on an opposing side of the adaptor piston 1062. When a force on the adaptor piston 1062 resulting from the pressure in the activation chamber 1088 exceeds an opposing force on the adaptor piston 1062 resulting from the pressure external to the debris collection tool 1000, the adaptor piston 1062 will experience a net force urging the adaptor piston 1062 to move longitudinally away from the bulkhead 1006. Figure 26A shows the adaptor piston 1062 having moved to a position at which the debris collection tool 1000 is in the activated configuration.

[0091] Still referring to Figures 26A and 26B, when the adaptor piston 1062 moves longitudinally, the adaptor extension 1068 and the adaptor skirt 1064 may move in the same direction. When the adaptor skirt 1064 moves longitudinally, the adaptor sleeve 1044 may move in the same direction. When the adaptor sleeve 1044 moves longitudinally, the yoke 1056 of the linkage 1046 may move in the same direction. When the yoke 1056 moves longitudinally, the elongate member(s) 1054 may move in the same direction with respect to the bulkhead 1006, and the key(s) 1052 may move longitudinally within the slot(s) of the mandrel 1008. Longitudinal movement of the key(s) 1052 may cause the inner sleeve 1042 to move in the same direction.

[0092] With reference to Figures 26B and 26C, longitudinal movement of the inner sleeve 1042 may move the inner magnet array 1048 longitudinally with respect to the outer magnet array 1024, the upper shield 1022, and the lower shield 1026. Rotational alignment of the inner magnet array 1048 with respect to the outer magnet array 1024 may be maintained at least in part by the bridges 1040 of the rings 1036 of outer magnets 1038 interspersed between the inner magnets 1076. Rotational alignment of the inner magnet array 1048 with respect to the outer magnet array 1024 may be maintained at least in part by the bridges 1040 of the rings 1036 of outer magnets 1038 being inserted in the longitudinal grooves 1074 of the inner sleeve 1042. Such longitudinal movement of the inner magnet array 1048 displaces each ring 1078 of inner magnets 1076. Thus, the first ring 1078 of inner magnets 1076 is displaced from a location of radial alignment with the lower shield 1026 to a position whereby each inner magnet 1076 of the first ring 1078 of inner magnets 1076 become radially aligned with a corresponding outer magnet 1038 of the first ring 1036 of outer magnets 1038. Each ring 1078 of inner magnets 1076 may be similarly displaced from radial alignment with one ring 1036 of outer magnets 1038 to become radially aligned with an adjacent ring 1036 of outer magnets 1038. However, in some embodiments, the last ( n+1 ^ih ) ring 1078 of inner magnets 1076 may be displaced from radial alignment with the last (n ^th ) ring 1036 of outer magnets 1038 to become radially aligned with the upper shield 1022.

[0093] Figure 27A presents a schematic lateral cross-section of the debris collection tool 1000 to illustrate exemplary juxtapositions of the inner magnets 1076 and the outer magnets 1038 in the inactive configuration. Figure 27B presents a schematic lateral cross-section of the debris collection tool 1000 to illustrate an exemplary magnetic field resulting from the arrangement shown in Figure 27A.

[0094] Figure 27 A shows a ring 1036 of outer magnets 1038 radially aligned with a ring 1078 of inner magnets 1076. Additionally, each outer magnet 1038 of the ring 1036 of outer magnets 1038 is radially aligned with a corresponding inner magnet 1076 of the ring 1078 of inner magnets 1076. In Figure 27A, the North pole of each outer magnet 1038 is adjacent to, and radially aligned with, the South pole of a corresponding inner magnet 1076. Similarly, the South pole of each outer magnet 1038 is adjacent to, and radially aligned with, the North pole of a corresponding inner magnet 1076. Additionally, the North pole of each outer magnet 1038 is circumferentially adjacent the North pole of a neighboring outer magnet 1038, and the South pole of each outer magnet 1038 is circumferentially adjacent the South pole of a neighboring outer magnet 1038. Furthermore, the North pole of each inner magnet 1076 is circumferentially adjacent the North pole of a neighboring inner magnet 1076, and the South pole of each inner magnet 1076 is circumferentially adjacent the South pole of a neighboring inner magnet 1076.

[0095] As illustrated in Figure 27B, because of the arrangement described above, a magnetic field 1104 emanating from (for example) the North pole of an outer magnet 1038 is repelled by the North pole of the circumferentially adjacent neighboring outer magnet 1038, but is attracted to the South pole of the radially adjacent neighboring inner magnet 1076. Similarly, a magnetic field 1104 emanating from (for example) the North pole of an inner magnet 1076 is repelled by the North pole of the circumferentially adjacent neighboring inner magnet 1076, but is attracted to the South pole of the radially adjacent neighboring outer magnet 1038. Therefore, the magnetic fields 1104 may be substantially contained in the areas between circumferentially and radially adjacent magnets. Since these areas contain the bridges 1040 of the rings 1036 of outer magnets 1038, and the bridges 1040 may be constructed out of magnetic material, the magnetic fields 1104 may be concentrated in the bridges 1040. Such a concentration of the magnetic fields 1104 may result in the debris collection tool 1000 projecting a weak, negligible, or substantially no, magnetic field into the environment immediately external to the cover 1012. Therefore, when the debris collection tool 1000 is in the inactive configuration, very little, or substantially no, magnetic debris may accumulate in the debris collection zone 1096.

[0096] Figure 28A presents a schematic lateral cross-section of the debris collection tool 1000 to illustrate exemplary juxtapositions of the inner magnets 1076 and the outer magnets 1038 in the activated configuration. Figure 28B presents a schematic lateral cross-section of the debris collection tool 1000 to illustrate an exemplary magnetic field resulting from the arrangement shown in Figure 28A.

[0097] For the purposes of illustration, the ring 1036 of outer magnets 1038 in Figure 28A is the same ring 1036 of outer magnets 1038 in Figure 27A. Flowever, because the inner sleeve 1042 with the inner magnet array has moved longitudinally, the ring 1078 of inner magnets 1076 of Figure 27A has been replaced by a new ring 1078 of inner magnets 1076 that is axially adjacent to the ring 1078 of inner magnets 1076 of Figure 27A. Thus, if the ring 1078 of inner magnets 1076 of Figure 27A is the r* ^h ring 1078 of inner magnets 1076, the new ring 1078 of inner magnets 1076 of Figure 28A would be the r-1 ^tu ring 1078 of inner magnets 1076.

[0098] Consistent with the ring 1078 of inner magnets 1076 in Figure 27A, the North pole of each inner magnet 1076 in Figure 28A is circumferentially adjacent the North pole of a neighboring inner magnet 1076, and the South pole of each inner magnet 1076 is circumferentially adjacent the South pole of a neighboring inner magnet 1076. In contrast to Figure 27A, however, Figure 28A shows that the North pole of each outer magnet 1038 is adjacent to, and radially aligned with, the North pole of a corresponding inner magnet 1076. Similarly, the South pole of each outer magnet 1038 is adjacent to, and radially aligned with, the South pole of a corresponding inner magnet 1076.

[0099] As illustrated in Figure 28B, because of the arrangement described above, a magnetic field 1104 emanating from (for example) the North pole of an outer magnet 1038 is repelled by the North pole of the circumferentially adjacent neighboring outer magnet 1038, and is repelled by the North pole of the radially adjacent neighboring inner magnet 1076. Therefore, the magnetic fields 1104 are not substantially contained in the areas between circumferentially and radially adjacent magnets. Instead, the magnetic field 1104 created by each outer magnet 1038 may extend from the North pole of the outer magnet 1038 outward through the cover 1012 into the environment external to the debris collection tool 1000, and return through the cover 1012 to the South pole of the outer magnet 1038. The relative lack of containment of the magnetic fields 1104 in the areas between circumferentially and radially adjacent magnets may cause the magnetic field 1104 in the environment external to the debris collection tool 1000 to be relatively strong compared to when the debris collection tool 1000 is in the inactive configuration. Therefore, when the debris collection tool 1000 is in the activated configuration, magnetic items in the environment external to the debris collection tool 1000 may be attracted to the debris collection zone 1096, and magnetic debris may accumulate in the debris collection zone 1096.

[00100] As shown in Figure 28B, a magnetic field 1104 may pass through the mandrel 1008. In some embodiments, the mandrel 1008 may be constructed out of a magnetic material, and may have a sufficiently large wall thickness such that the magnetic field experienced in the central longitudinal flowbore 1020 through the mandrel 1008 may be relatively weak. Flence, a propensity for magnetic particles to accumulate in the central longitudinal flowbore 1020 through the mandrel 1008 may be mitigated.

[00101] In use, the debris collection tool 1000 may be coupled to a workstring. In some embodiments, the debris collection tool 1000 may be coupled to a workstring to which one or more additional tool may be coupled. The additional tool(s) may include, without limitation, any one or more of a cutting tool, a scraping tool, a perforating tool, a drilling tool, a milling tool, a motor, an explosive tool, a jetting tool, a filter tool, a circulation diverting tool, a packer, a packer setting tool, a bridge plug, a bridge plug setting tool, a liner expansion tool, a cementing tool, a pressure testing tool, an inflow testing tool, a pressure surge mitigation tool, a seat for a ball or dart, a catcher for a ball or dart, a fishing tool, a disconnect tool, a data gathering tool, a data recording tool, a telemetry tool, or combination(s) thereof.

[00102] The workstring with the debris collection tool 1000 may be inserted into a wellbore. As shown in Figure 29, the debris collection tool 1000 may be initially in the inactive configuration upon insertion in the wellbore 1156. If present, other tools on the workstring may be actuated in the wellbore 1156 while the debris collection tool 1000 is in the inactive configuration. As shown in Figure 29, magnetic particles 1158 may not accumulate in the debris collection zone 1096. The debris collection tool 1000 may be transitioned to the activated configuration while in the wellbore 1156.

[00103] As described above, the debris collection tool 1000 may be transitioned to the activated configuration by the application of pressure in the central longitudinal flowbore 1020. Such pressurizing may be achieved by pumping a fluid through the workstring into the central longitudinal flowbore 1020. The pressurizing may be assisted by pumping the fluid through a nozzle below the debris collection tool 1000, such that the flow of the fluid through the nozzle creates a back pressure that is experienced in the central longitudinal flowbore 1020. The pressurizing may be assisted by landing a blocking object, such as a ball or a dart, on a seat below the activation chamber 1088 of the debris collection tool 1000. The seat may be part of the debris collection tool 1000, or may be positioned below the debris collection tool 1000. The blocking object may substantially obstruct the passage of fluid therearound, and thus further pumping of fluid after the blocking object lands on the seat will increase the pressure in the workstring and in the longitudinal flowbore of the debris collection tool 1000.

[00104] Once transitioned into the activated configuration, the debris collection tool 1000 may now attract magnetic particles 1158 to the debris collection zone 1096, as shown in Figure 30. The debris collection tool 1000 may remain in the activated configuration while other tools on the workstring are actuated. The debris collection tool 1000 may remain in the activated configuration while the workstring and the debris collection tool 1000 are retrieved from the wellbore 1156.

[00105] The debris collection tool 1000 may be coupled to a controller for use in a wellbore 1156. Figure 31 shows a controller 1106 with a debris collection tool 1000. The controller 1106 may be configured to couple to an upper end of the upper housing 1002 of the debris collection tool 1000. A control sleeve (not shown) in the controller 1106 may be configured to couple to the adaptor extension 1068 or to the adaptor piston 1062 of the debris collection tool 1000.

[00106] In some embodiments, the controller 1106 may selectively prevent or allow movement of the adaptor sleeve 1044, thereby selectively preventing or allowing the debris collection tool 1000 to transition between inactive and activated configurations. The controller 1106 may switch between preventing and allowing the debris collection tool 1000 to transition between inactive and activated configurations upon being triggered. In some embodiments, the controller 1106 may be triggered by landing a dropped object on a seat, such as per a controller depicted in U.S. patent no. 8,540,035, the disclosure of which is incorporated herein by reference.

[00107] In some embodiments, the controller 1106 may be triggered by telemetry of a signal. The signal may be conveyed to the controller 1106 by any one of: a RFID tag; electronically through a wire; electromagnetically; acoustically through a fluid, such as a fluid pressure pulse; acoustically through the workstring or a casing of a wellbore 1156; fluid flow modulation; workstring manipulation, such as rotation and/or axial movement; or combination(s) thereof. The controller 1106 may operate similarly to any of the controllers depicted in U.S. patent numbers 8,540,035; 9,115,573; 9,382,769; and 10,087,725; the disclosures of which are incorporated herein by reference.

[00108] Flence, the debris collection tool 1000 may be maintained in the inactive configuration by the controller 1106 even if the debris collection tool 1000 experiences a pressure in the longitudinal flowbore that otherwise would be sufficient to trigger the debris collection tool 1000 to transition into the activated configuration. Therefore, the controller 1106 may prevent premature activation of the debris collection tool 1000 while other operations (such as cutting, scraping, milling, packer setting, pressure testing, fishing, etc.) are being conducted using the workstring and any other tools coupled to the workstring. When it is desired to activate the debris collection tool 1000, the controller 1106 may be prompted by any of the techniques described above and in the above-cited references to permit upward movement of the adaptor sleeve 1044, and any attached components of the adaptor assembly 1060. Then, the application of sufficient pressure in the longitudinal flowbore of the debris collection tool 1000 may activate the debris collection tool 1000, as described above.

[00109] Figure 32 shows a controller 1106 with the debris collection tool 1000. The controller 1106 may selectively prevent or allow movement of the adaptor sleeve 1044, thereby selectively preventing or allowing the debris collection tool 1000 to transition between inactive and activated configurations. The controller 1106 may be configured to switch selectively between preventing and allowing the transition of the debris collection tool 1000 without requiring the use of a blocking object landing on a seat and without requiring the use of telemetry. The controller 1106 may be configured to couple to the bulkhead 1006 of the debris collection tool 1000. Hence, the upper housing 1002 and upper centralizer 1004 may be omitted from the debris collection tool 1000.

[00110] Figures 33 and 34 show a longitudinal cross-sectional view of the controller 1106 of Figure 32 together with an upper portion of the debris collection tool 1000. Figure 33 illustrates components of the controller 1106 when the debris collection tool 1000 is in the inactive configuration. Figure 34 illustrates components of the controller 1106 when the debris collection tool 1000 is in the activated configuration.

[00111] T urning to Figure 33, the controller 1106 may have a top sub 1108 coupled to a block housing 1110. In some embodiments, the top sub 1108 and the block housing 1110 may be integrally formed. The block housing 1110 may be coupled to a piston housing 1112. The piston housing 1112 may include a centralizer 1114. The piston housing 1112 may be coupled to a bottom sub 1116. In some embodiments, as shown in Figure 33, the piston housing 1112 and the bottom sub 1116 may be integrally formed. The bottom sub 1116 may be coupled to the debris collection tool 1000. As shown in Figure 33, the bottom sub 1116 may be coupled to the bulkhead 1006 of the debris collection tool 1000.

[00112] The piston housing 1112 may have a piston chamber 1118. A control piston 1120 may be located inside the piston chamber 1118. One or more seal 1121 may inhibit the passage of fluid between the control piston 1120 and an inner wall of the piston chamber 1118. The control piston 1120 may be positioned proximate to a lower end of the piston chamber 1118. A biasing member 1122, such as a spring, may inhibit the control piston 1120 from moving axially away from the lower end of the piston chamber 1118. The control piston 1120 may be coupled to a piston sleeve 1124 that extends from the control piston 1120, through the piston chamber 1118, and into the block housing 1110. In some embodiments, the control piston 1120 and the piston sleeve 1124 may be integrally formed. The control piston 1120 may be coupled to an extension sleeve 1126 that extends from the control piston 1120 into the bottom sub 1116. In some embodiments, the control piston 1120 and the extension sleeve 1126 may be integrally formed. The adaptor sleeve 1044 of the debris collection tool 1000 may be coupled to the extension sleeve 1126. The adaptor sleeve 1044 may be coupled to the extension sleeve 1126 in a similar manner to the coupling between the adaptor sleeve 1044 and the adaptor skirt 1064, illustrated in Figures 25A and 25B.

[00113] In some alternative embodiments, the adaptor sleeve 1044 may be coupled to the adaptor extension 1068, and the adaptor extension 1068 may be coupled to the extension sleeve 1126. The adaptor sleeve 1044 may be coupled to the adaptor extension 1068 in a similar manner to the coupling between the adaptor sleeve 1044 and the adaptor skirt 1064, illustrated in Figures 25A and 25B.

[00114] As illustrated in Figure 33, a central longitudinal flowbore 1128 of the controller 1106 may extend from the top sub 1108, through the piston sleeve 1124, control piston 1120 and extension sleeve 1126, and be fluidically coupled to the central longitudinal flowbore 1020 of the debris collection tool 1000. [00115] As illustrated in Figure 33, because the bottom sub 1116 of the controller 1106 is coupled to the bulkhead 1006 of the debris collection tool 1000, the activation chamber 1088 of the debris collection tool 1000 is defined at least in part by the bottom sub 1116 and the bulkhead 1006. A bottom side of the control piston 1120 may be fluidically coupled to the activation chamber 1088.

[00116] The portion of the piston chamber 1118 above the control piston 1120 and between an external surface of the piston sleeve 1124 and an internal surface of the piston housing 1112, may contain a control fluid, such as a hydraulic oil. The piston chamber 1118 may be bounded at an upper end by a valve block 1130 of the block housing 1110. The valve block 1130 may separate the piston chamber 1118 from an upper chamber 1134 of the block housing 1110. A transfer bore 1132 in the valve block 1130 may provide a fluid pathway between the piston chamber 1118 and the upper chamber 1134. The transfer bore 1132 may have a check valve 1136. The check valve 1136 may allow the passage of control fluid from the piston chamber 1118 to the upper chamber 1134, but inhibit the passage of control fluid from the upper chamber 1134 to the piston chamber 1118. A reset bore 1138 in the valve block 1130 may provide a fluid pathway between the piston chamber 1118 and the upper chamber 1134. The reset bore 1138 may have a stop valve 1140. The stop valve 1140 may be adjustable to selectively allow or inhibit the passage of control fluid from the piston chamber 1118 to the upper chamber 1134, and the passage of control fluid from the upper chamber 1134 to the piston chamber 1118. In some embodiments, the stop valve 1140 may be a removable plug.

[00117] The upper chamber 1134 may contain a balance piston 1142. The balance piston 1142 may be sealed against an inner surface of the block housing 1110 and an outer surface of the piston sleeve 1124 that extends through the block housing 1110, and therefore separates the upper chamber 1134 into upper and lower portions. Hence, the transfer bore 1132 and the reset bore 1138 of the valve block 1130 may be fluidically coupled with the lower portion of the upper chamber 1134. The block housing 1110 may have a port 1144 that allows the pressure of fluid external to the block housing 1110 to be communicated to the upper portion of the upper chamber 1134. [00118] A piston block 1146 may be coupled to and around the piston sleeve 1124 within the upper chamber 1134. The piston block 1146 may be configured to move axially as a result of the piston sleeve 1124 moving axially. The piston block 1146 may be temporarily retained in a first position by a fastener 1148, such as a latch, locking dog, collet, snap ring, shear ring, shear screw, shear pin, or the like. The fastener 1148 may temporarily secure the piston block 1146 to the block housing 1110. Thus, the piston block 1146, piston sleeve 1124, control piston 1120, and extension sleeve 1126 may be temporarily inhibited from moving axially. As a result of this, the adaptor sleeve 1044 may be temporarily inhibited from moving axially, and therefore the debris collection tool 1000 may be temporarily maintained in the inactive configuration. In some embodiments, the fastener 1148 may be omitted. Nevertheless, the piston block 1146, piston sleeve 1124, control piston 1120, and extension sleeve 1126 may be temporarily inhibited from moving axially upward because of a downward force produced by the biasing member 1122 and the pressure of the control fluid in the piston chamber 1118. Hence, in use, when coupled to a workstring, the debris collection tool 1000 may be maintained in the inactive configuration while the workstring and other tools coupled to the workstring may be operated by fluid pressures that otherwise would transition the debris collection tool 1000 to the activated configuration. Thus, the debris collection may be selectively transitioned from the inactive configuration to the active configuration.

[00119] In order to transition the debris collection tool 1000 to the activated configuration, an activation pressure may be applied in the central longitudinal flowbore 1020 of the debris collection tool 1000. As described above, pressure applied in the central longitudinal flowbore 1020 of the debris collection tool 1000 may be communicated around the adaptor sleeve 1044 to the activation chamber 1088. The pressure in the activation chamber 1088 may be communicated to the bottom of the control piston 1120 of the controller 1106, resulting in the control piston 1120 experiencing an upwardly-directed force. This upwardly-directed force may be counteracted by the downward force produced by the biasing member 1122 and the pressure of the control fluid in the piston chamber 1118. In embodiments that include the fastener 1148, the upwardly-directed force on the control piston 1120 is also resisted by the fastener 1148. By increasing the pressure in the central longitudinal flowbore 1020 of the debris collection tool 1000, the pressure in the activation chamber 1088 increases. Thus the pressure on the bottom of the control piston 1120 of the controller 1106 increases, and the upwardly-directed force on the control piston 1120 increases accordingly. When the upwardly-directed force on the control piston 1120 exceeds the resistance provided by the downward force produced by the biasing member 1122 and the pressure of the control fluid in the piston chamber 1118 plus the force required to defeat the fastener 1148 (if present), such as a shear force, the control piston 1120 may begin to move upward.

[00120] When the control piston 1120 moves upward, control fluid in the piston chamber 1118 flows through the transfer bore 1132, through the check valve 1136, and into the lower portion of the upper chamber 1134. The balance piston 1142 may therefore move upward, and some of the fluid in the upper portion of the upper chamber 1134 may be vented to an exterior of the controller 1106 through the port 1144. Because the control piston 1120 moves upward, the piston sleeve 1124 and piston block 1146 also move upward. Additionally, the extension sleeve 1126 moves upward, as does the adaptor sleeve 1044 of the debris collection tool 1000 to which the extension sleeve 1126 is coupled. As described above, this results in the linkage 1046 moving upward, and thus the inner sleeve 1042 and inner magnet array 1048 of the debris collection tool 1000 also move upward. Hence, the debris collection tool 1000 transitions from the inactive configuration to the activated configuration.

[00121] Per the preceding description, Figure 34 shows the controller 1106 and the upper portion of the debris collection tool 1000 of Figure 33 when the debris collection tool 1000 has transitioned to the activated configuration. Although the application of pressure in the central longitudinal flowbore 1020 of the debris collection tool 1000 is required to transition the debris collection tool 1000 to the activated condition, the pressure need not be maintained in order to retain the debris collection tool 1000 in the activated condition. Upon reducing the pressure in the central longitudinal flowbore 1020 of the debris collection tool 1000, the control piston 1120 may experience a net downward force from the biasing member 1122 and any residual pressure of the control fluid in the piston chamber 1118. However, the control piston 1120 may be pressure-locked because the control fluid in the lower portion of the upper chamber 1134 is inhibited from transferring back into the piston chamber 1118. The stop valve 1140 inhibits fluid flow through the reset bore 1138, and the check valve 1136 inhibits fluid flow back into the piston chamber 1118 through the transfer bore 1132. Thus, once the debris collection tool 1000 has been transitioned to the activated configuration, the controller 1106 may resist the influence of further operational pressure fluctuations and manipulations, hence maintaining the debris collection tool 1000 in the activated configuration. Accordingly, an inadvertent transition of the debris collection tool 1000 back to the inactive configuration, which would result in the release of accumulated particles, may be avoided. Therefore, magnetic debris may accumulate in the debris collection zone 1096, and may remain in place while the debris collection tool 1000 is retrieved from the wellbore 1156.

[00122] When the controller 1106 and debris collection tool 1000 are retrieved from a wellbore 1156, the debris collection tool 1000 may be transitioned back to the inactive configuration to allow for the accumulated debris to be released, and to allow for the debris collection tool 1000 to be run anew into the wellbore 1156. Furthermore, the controller 1106 may be reset.

[00123] As shown in Figure 34, the fastener 1148 has been defeated, and in this case has become separated into two pieces 1148a and 1148b. The pieces 1148a and 1148b may be removed, and the fastener 1148 may be replaced once the controller 1106 has been reset. The piece 1148a remaining in a wall of the block housing 1110 may be removed by conventional methods. The piece 1148b in the piston block 1146 may be removed through an access port 1150. Alignment between the piston block 1146 and the access port 1150 may be maintained by an alignment key 1152 in a wall of the block housing 1110 interacting with an alignment slot 1154 in the piston block 1146.

[00124] To reset the controller 1106 and transition the debris collection tool 1000 back to an inactive configuration, a flow path may be established for the control fluid to travel from the lower portion of the upper chamber 1134 to the piston chamber 1118, thereby releasing the control piston 1120 from the hydraulic lock. The establishment of the fluid flow path may be achieved by adjustment of the stop valve 1140 to open the flow path through the reset bore 1138. In some embodiments, the stop valve 1140 may be switched from a closed condition to an open condition. In some embodiments, the stop valve 1140 may be removed. In some embodiments, the stop valve 1140 may be partially removed, sufficiently to open the flow path through the reset bore 1138. Upon opening the flow path through the reset bore 1138, the biasing member 1122 may push the control piston 1120 downward, and control fluid may flow through the reset bore 1138 from the lower portion of the upper chamber 1134 into the piston chamber 1118. When the control piston 1120 has reached the end of its travel, the stop valve 1140 may be adjusted to close the flow path through the reset bore 1138.

[00125] Downward movement of the control piston 1120 results in downward movement of the piston block 1146. When the control piston 1120 has reached the end of its travel, a replacement fastener 1148 may be inserted into the piston block 1146. In some embodiments, the replacement fastener 1148 may be omitted. Downward movement of the control piston 1120 also results in downward movement of the extension sleeve 1126, and hence downward movement of the adaptor sleeve 1044 and the linkage 1046 of the debris collection tool 1000. Thus, the inner sleeve 1042 and inner magnet array 1048 of the debris collection tool 1000 also move downward. Hence, the debris collection tool 1000 transitions from the activated configuration to the inactive configuration. Debris accumulated around the debris collection tool 1000 may be cleared from the debris collection tool 1000, and the debris collection tool 1000 may then be run back into the wellbore 1156, if required.

[00126] Various embodiments have been described of a debris collection tool and other apparatus associated with a debris collection tool. In one embodiment, a debris collection tool may include a mandrel having a longitudinal flowbore therethrough and an inner sleeve disposed around the mandrel. A first array of magnets may be arranged on the inner sleeve. A second array of magnets may be disposed around the inner sleeve. The debris collection tool further may include an adaptor sleeve concentric with the mandrel and a linkage coupling the adaptor sleeve with the inner sleeve. [00127] In another embodiment, a debris collection tool may include a mandrel having a longitudinal flowbore therethrough and an inner sleeve disposed around the mandrel. A first array of magnets may be arranged on the inner sleeve. The first array of magnets may include a plurality of inner magnets disposed around a circumference of the inner sleeve. The inner sleeve may have a longitudinal groove between two adjacent magnets of the first array of magnets. The debris collection tool further may include a second array of magnets disposed around the inner sleeve. The second array of magnets may include an annular arrangement of magnets between a pair of axially spaced end bands and may include a bridge between two circumferentially adjacent magnets. The bridge may be configured to project into the longitudinal groove. In some embodiments, the debris collection tool further may include an adaptor sleeve concentric with the mandrel and a linkage coupling the adaptor sleeve with the inner sleeve.

[00128] In another embodiment, a magnet assembly may include first and second annular end bands and may include an annular arrangement of magnets disposed between the first and second annular end bands. The first and second annular end bands may include substantially a non-magnetic material. The magnet assembly further may include a plurality of bridges. Each bridge may be disposed between the first and second annular end bands and between circumferentially adjacent magnets of the annular arrangement of magnets. The bridges may include substantially a magnetic material.

[00129] In another embodiment, a controller for a wellbore tool may include a first housing defining a first chamber, and a second housing coupled to the first housing and defining a second chamber. The controller further may include a valve block separating the first and second chambers. A piston may be axially movable within the first chamber. A sleeve may be coupled to the piston, and may extend from the first chamber into the second chamber through the valve block. A fastener may be coupled to sleeve and may be coupled to the second housing. The controller further may include a central longitudinal flowbore through the sleeve and the piston. A first bore through the valve block may fluidically couple an annulus between the sleeve and the first housing with the second chamber, and a check valve may be associated with the first bore. A second bore through the valve block may fluidically couple an annulus between the sleeve and the first housing with the second chamber, and a stop valve may be associated with the second bore.

[00130] While the foregoing is directed to embodiments of the present invention, other and further embodiments of the invention may be devised without departing from the basic scope thereof, and the scope thereof is determined by the claims that follow.