Through-the-well tool

Abstract

This invention relates to a well cleaning tool, specifically in the field of oil and gas field development technology. The well cleaning tool of this invention includes: a main body, with a guide head connected to the bottom and a centralizing sleeve connected to the upper end; the maximum outer diameter of the guide head and centralizing sleeve is larger than the maximum outer diameter of the main body, facilitating the well cleaning process; wherein the guide head and centralizing sleeve are constructed to be corroded by acid. When the well cleaning tool becomes stuck and cannot be resolved conventionally, acid can be injected to dissolve the guide head and centralizing sleeve, reducing their outer diameter and thus releasing the stuck tool. The main body also includes a release assembly, with a locking design between the two via a lower connector; if acid etching fails to release the stuck tool, a ball can be dropped into the wellbore, pumped to the locking cylinder, pressurized, and sheared off the shear pins. At this point, the locking fails, and the release assembly can be pulled out of the wellbore to release the stuck tool. This well cleaning tool possesses dissolution and diameter reduction functions as well as an emergency release assembly, improving its ability to handle stuck well cleaning operations and ensuring the safety of well cleaning operations.

Description

Technical Field

[0001] This invention relates to the field of oil and gas field development technology, and in particular to a well cleaning tool. Background Technology

[0002] In various construction activities such as oil and gas field production and development, and downhole operations, well cleaning operations are necessary to diagnose the actual condition of the wellbore and ensure its normal operation. This typically involves lowering cleaning tools to the bottom of the well to test their accessibility and ensure the proper lowering of subsequent tools.

[0003] Currently, well cleaning typically employs mechanical methods, using tools such as well gauges, coiled wireline tubing, and well shoes. However, this approach suffers from drawbacks including long cleaning times, poor cleaning efficiency, and limited tool variety. When encountering obstruction, the tool's own weight is typically used for lifting and lowering, or explosive cutting is employed to resolve the issue. However, for branch wells, well cleaning operations often occur after the branch well window tool has been lowered. These tools have complex structures, and existing well cleaning tools are rigid and strong. When passing through the window tool, there is a risk of getting stuck. Excessive lifting and lowering for unblocking operations or conventional techniques like explosive cutting can easily damage the window tool, causing greater harm to the entire well.

[0004] In other words, current well cleaning tools either have problems with detachment from the well or damage the downhole environment, and are no longer suitable for current well cleaning requirements. Summary of the Invention

[0005] This invention provides a well cleaning tool, which is designed to be easily retrieved.

[0006] The present invention provides a well cleaning tool, comprising: a main body, wherein a guide head is connected to the bottom of the main body, the maximum outer diameter of the guide head being larger than the maximum outer diameter of the main body; wherein the guide head is constructed to be corroded by acid.

[0007] The main body is also equipped with a straightening sleeve, which is spaced apart from the guide head. The maximum outer diameter of the straightening sleeve is larger than the maximum outer diameter of the main body, and the straightening sleeve is constructed to be corroded by acid.

[0008] In one embodiment, the guide head is made of an acid-etchable metal material.

[0009] In one embodiment, the material of the straightening sleeve is an acid-etchable metal material.

[0010] In one embodiment, the well-dredging tool further includes a release assembly, which includes a first connector, a tightening member, and a driving member;

[0011] The first connector includes a resilient connecting portion located at its bottom, the resilient connecting portion being inserted into the interior of the body;

[0012] The expansion member is installed inside the first connector to radially open the elastic connection portion, thereby locking the elastic connection portion with the main body;

[0013] The driving member is used to push the expansion member to move axially, so as to drive the expansion member to separate from the first connecting member, thereby unlocking the elastic connection part from the main body.

[0014] In one embodiment, the resilient connection includes a limiting protrusion extending radially outward, and a limiting groove is formed inside the body. The limiting protrusion is inserted into the limiting groove to lock the first connector to the body.

[0015] In one embodiment, the release assembly further includes a second connector mounted on top of the first connector. The first connector has a first hole, and the tensioning member is installed in the first hole. The second connector has a second hole, and the first hole and the second hole are connected to form a first channel. The drive member is configured to fall along the first channel to pump to the tensioning member.

[0016] In one embodiment, the expansion member has an axially extending third hole, which communicates with the second hole;

[0017] The third hole includes a large hole section and a small hole section that are connected to each other. The large hole section is located above the small hole section, and the diameter of the large hole section is larger than that of the small hole section. The outer diameter of the driving member is smaller than the inner diameter of the large hole section but larger than the inner diameter of the small hole section.

[0018] In one embodiment, the well-dredging tool achieves pressure build-up through a drive component and a small hole section, thereby driving the expansion member to move downwards.

[0019] In one embodiment, the expansion member is connected to the first connector via a shear pin, the shear pin being configured to break when subjected to a shear force greater than or equal to a first shear force, and the maximum pushing force of the drive member is greater than the first shear force.

[0020] In one embodiment, a shearing ring is also installed outside the expansion member for installing shear pins and fixing the expansion member and the first connecting member.

[0021] Compared with the prior art, the advantage of this invention is that it enables efficient well cleaning operations by utilizing the guide head and centralizing sleeve located at the bottom of the main body. Because the guide head and centralizing sleeve are designed to be corroded by acid, when the well cleaning tool gets stuck, acid can be introduced into the wellbore to dissolve the guide head and centralizing sleeve, thereby reducing the outer diameter of the well cleaning tool and facilitating its removal from the wellbore.

[0022] If acid etching is ineffective, a ball can be dropped into the wellbore, i.e., the drive component, to break the shear pin by pressing down, causing the expansion component to descend and release the locking from the main body. The release assembly can then be lifted with a certain load, leaving only the main body downhole. This eliminates the need for explosive cutting and better protects the window and wellbore. Attached Figure Description

[0023] The invention will now be described in more detail with reference to embodiments and the accompanying drawings.

[0024] Figure 1 This is a cross-sectional view of the well-dredging tool in an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 A schematic diagram of the local structure at point A in the middle.

[0026] Figure label:

[0027] 100. Main body;

[0028] 200. Guide head; 210. Flow guide hole;

[0029] 300. Correcting set;

[0030] 400, release assembly; 410, first connector; 411, elastic connection; 4111, limiting protrusion; 420, tensioning component; 421, third hole; 4211, large hole section; 4212, small hole section; 430, driving component; 440, second connector; 450, scissor pin;

[0031] 500, First channel; 510, Second hole;

[0032] 601. First seal; 602. Second seal;

[0033] 701, First pin; 702, Second pin; 703, Shear ring. Detailed Implementation

[0034] The invention will now be further described with reference to the accompanying drawings.

[0035] See Figure 1 and Figure 2As shown, this embodiment of the invention provides a well cleaning tool, which includes: a main body 100 and a guide head 200. The guide head 200 is connected to the bottom of the main body 100, and the maximum outer diameter of the guide head 200 is larger than the maximum outer diameter of the main body 100.

[0036] When well cleaning tools get stuck, it is usually the larger-diameter guide head 200 that gets stuck in the well wall. Since the guide head 200 is designed to be corroded by acid, if it gets stuck during well cleaning, acid can be introduced into the wellbore to corrode the guide head 200, thereby reducing the maximum outer diameter of the well cleaning tool, relieving the sticking, and making it easier to remove the well cleaning tool from the wellbore. This significantly reduces the difficulty of removing the well cleaning tool during well cleaning.

[0037] See Figure 1 and Figure 2 As shown, in some implementations, the bottom of the seeker head 200 is provided with a tapered tip, which can guide the well cleaning tool during its descent. The axis of the tapered tip is collinear with the axis of the main body 100, and the outer diameter of the tapered tip increases uniformly from bottom to top, resulting in a smoothly transitioned tapered surface on the outer surface of the tapered tip.

[0038] See Figure 1 As shown, in some implementations, the bottom of the guide head 200 is also provided with a guide hole 210. As the well cleaning tool moves downward, the liquid or gas in the wellbore can be discharged through the guide hole 210, making the downward movement of the well cleaning tool smoother.

[0039] See Figure 1 As shown, in some implementations, the guide head 200 is mounted outside the body 100 via a first pin 701. The guide head 200 has an internal thread, and the body 100 has an external thread. The guide head 200 is mounted outside the body 100 via a threaded connection between the body 100 and the guide head 200. Of course, the connection method between the body 100 and the guide head 200 is not limited to pin connection or threaded connection; various connection methods such as snap-fit ​​and welding can also be used, as long as the body 100 and the guide head 200 can be connected.

[0040] In some implementations, the seeker head 200 is made of an acid-etchable metal material that can dissolve rapidly in an acidic environment, resulting in complete dissolution or surface dissolution of the seeker head 200. This reduces the maximum outer diameter of the wellbore cleaning tool, making it easier to remove the tool from the wellbore. Furthermore, the seeker head 200 can be made of a soluble aluminum alloy, a type of acid-etchable metal.

[0041] See Figure 1As shown, in some implementations, a centralizing sleeve 300 is also installed on the main body 100. The centralizing sleeve 300 is spaced apart from the guide head 200. The maximum outer diameter of the centralizing sleeve 300 is larger than the maximum outer diameter of the main body 100, and the centralizing sleeve 300 is constructed to be corroded by acid. The well-drainage function can be efficiently achieved through the arrangement of the guide head and the centralizing sleeve. It can be understood that the centralizing sleeve 300 can be a roller-type centralizing sleeve 300, or it can be a one-piece rigid centralizing sleeve 300.

[0042] Because the centralizing sleeve 300 is designed to be corroded by acid, acid can be injected into the wellbore when the well cleaning tool is stuck. The acid can corrode not only the guide head 200 but also the centralizing sleeve 300, thereby reducing its outer diameter and making it easier to remove the well cleaning tool. The centralizing sleeve 300 can be made of a soluble aluminum alloy, which can dissolve relatively quickly in an acidic environment.

[0043] In some implementations, the maximum outer diameter of the centering sleeve 300 is equal to the maximum outer diameter of the guide head 200.

[0044] See Figure 1 As shown, in some implementations, the straightening sleeve 300 is connected to the main body 100 by the second pin 702 and installed outside the main body 100 by a threaded connection. Alternatively, a limiting groove can be provided outside the main body 100, and the straightening sleeve 300 can be installed by installing it in the limiting groove.

[0045] See Figure 1 and Figure 2 As shown, in some implementations, the well cleaning tool further includes a release assembly 400, which includes a first connector 410, a tightening member 420, and a driving member 430. The first connector 410 includes an elastic connecting portion 411 located at its bottom, which is inserted into the body 100. The tightening member 420 is installed inside the first connector 410 to radially open the elastic connecting portion 411, thereby locking the elastic connecting portion 411 to the body 100. The driving member 430 is used to push the tightening member 420 to move axially, thereby driving the tightening member 420 to separate from the first connector 410, thereby unlocking the elastic connecting portion 411 from the body 100.

[0046] During normal well cleaning, the elastic connection 411 is radially opened by the expansion member 420, so that the elastic connection 411 is locked with the main body 100, thereby realizing the locking connection between the first connector 410 and the main body 100 in the release assembly 400.

[0047] When encountering a stuck well during well cleaning, acid can be introduced into the wellbore first, which will corrode the larger diameter guide head 200 and centralizing sleeve 300, thereby reducing the maximum outer diameter of the well cleaning tool and making it easier to remove the tool.

[0048] If introducing acid into the wellbore still fails to allow the well-drilling tool to be successfully removed, the drive component 430 can push the expansion component 420 to move axially, causing the expansion component 420 to disengage from the first connecting component 410. This unlocks the elastic connection part 411 from the main body 100, and by lifting a certain load, the release assembly can be pulled out of the wellbore, leaving only the main body inside.

[0049] In other words, the separation of the main body 100 and the release assembly 400 can be achieved through the action of the driving component 430. Compared with solving the problem of well cleaning tools getting stuck by explosion, the present invention improves the ability to deal with well cleaning tools getting stuck, and can retrieve well cleaning tools more safely without damaging the wellbore.

[0050] See Figure 1 and Figure 2 As shown, in some implementations, the elastic connecting portion 411 includes a limiting protrusion 4111 extending radially outward, and a limiting groove is formed inside the main body 100. When the limiting protrusion 4111 is inserted into the limiting groove, the first connecting member 410 is locked to the main body 100. That is, the elastic connecting portion 4111 locks the first connecting member 410 to the main body 100 by inserting the limiting protrusion 4111 into the limiting groove.

[0051] When the tensioning member 420 is installed on the inner side of the first connector 410, the tensioning member 420 can keep the elastic connecting part 411 pressed towards the main body 100, thereby making the limiting protrusion 4111 of the elastic connecting part 411 more tightly connected with the limiting groove of the main body 100, preventing the limiting protrusion 4111 from disengaging from the limiting groove, and realizing the locking between the elastic connecting part 411 and the main body 100.

[0052] When the tensioning member 420 is pushed out of the first connecting member 410 by the driving member 430, since the inner side of the elastic connecting part 411 is not pressed by the tensioning member 420, the elastic connecting part 411 and the main body 100 are unlocked. A certain load is lifted, and the release assembly can be lifted out of the well, leaving only the main body inside the well.

[0053] See Figure 1 and Figure 2As shown, in some implementations, the release assembly 400 further includes a second connector 440, which is mounted on top of the first connector 410. The first connector 410 has a first hole, and the tensioning member 420 is installed in the first hole. The second connector 440 has a second hole 510, and the first hole and the second hole 510 are connected to form a first channel 500. The driving member falls along the first channel to pump to the tensioning member.

[0054] During normal well cleaning, the elastic connecting part 411 is radially opened using the expansion member 420, locking the elastic connecting part 411 to the main body 100, thus achieving a locking connection between the first connecting part 410 in the release assembly 400 and the main body 100. If the well cleaning tool becomes stuck, acid can be introduced into the wellbore to corrode the larger diameter guide head 200 and the centralizing sleeve 300, thereby reducing the maximum outer diameter of the well cleaning tool and lowering the difficulty of removing it. If introducing acid into the wellbore still fails to remove the tool smoothly, the expansion member 420 can be pushed axially by the drive member 430, causing the expansion member 420 to disengage from the first connecting part 410. This unlocks the elastic connecting part 411 from the main body 100, and by lifting a certain load, the release assembly can be pulled out of the wellbore, leaving only the main body inside.

[0055] See Figure 2 As shown, in some implementations, the tensioning member 420 has an axially extending third hole 421, which is connected to the second hole 510. The third hole 421 includes a large hole section 4211 and a small hole section 4212 that are connected. The large hole section 4211 is located above the small hole section 4212, and the diameter of the large hole section 4211 is larger than that of the small hole section 4212. The outer diameter of the driving member 430 is smaller than the inner diameter of the large hole section 4211 and larger than the inner diameter of the small hole section 4212.

[0056] In other words, the outer diameter of the driving component 430 is between the inner diameter of the large hole section 4211 and the inner diameter of the small hole section 4212. It should be noted that the tightening component 420 is installed inside the second hole 510, and the diameter of the third hole 421 opened in the tightening component 420 is smaller than the diameter of the second hole 510. The small hole section 4212 and the large hole section 4211 smoothly transition, forming a limiting hole structure. This allows the driving component 430 to be pumped to the limiting hole, achieving pressure buildup, thereby shearing the shear pin and enabling the release function.

[0057] See Figure 1 and Figure 2 As shown, in some implementations, the drive element 430 is a sphere with a uniform outer diameter at all points. In other implementations, the drive element 430 may also be a columnar structure or a column with a tapered bottom.

[0058] See Figure 1 and Figure 2 As shown, in some implementations, the tensioning member 420 is connected to the first connecting member 410 via a shear pin 450. The shear pin 450 is configured to break when the shear force it bears is greater than or equal to a first shear force, and the maximum pushing force of the driving member 430 is greater than the first shear force. That is, the tensioning member 420 is held within the first connecting member 410 by the shear pin 450, and the shear pin 450 can break when the driving member 430 pushes the tensioning member 420, thereby separating the tensioning member 420 from the first connecting member 410.

[0059] See Figure 1 and Figure 2 As shown, in some implementations, a shear ring 703 is also installed outside the tensioning member 420 for mounting shear pins and fixing the tensioning member and the first connecting member. Since there are seals on both the top and bottom of the shear ring, installing shear pins here can ensure the sealing of the device.

[0060] In some implementations, a first sealing element 601 is provided between the first connecting member 410 and the second connecting member 440 to seal the gap between them. A second sealing element 602 is also provided between the first connecting member 410 and the main body 100 to seal the gap between them. The use of the first sealing element 601 and the second sealing element 602 ensures a tight seal at the shear ring, thereby guaranteeing the overall airtightness of the device.

[0061] Although the invention has been described with reference to preferred embodiments, various modifications can be made and components can be replaced with equivalents without departing from the scope of the invention. In particular, the technical features mentioned in the various embodiments can be combined in any manner as long as there is no structural conflict. The invention is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A well cleaning tool, characterized in that, It includes: The main body has a guide head connected to its bottom, and the maximum outer diameter of the guide head is greater than the maximum outer diameter of the main body. The guide head is designed to be corroded by acid.

2. The well cleaning tool according to claim 1, characterized in that, The guide head is made of an acid-etchable metal.

3. The well cleaning tool according to claim 1 or 2, characterized in that, The main body is also equipped with a straightening sleeve, which is spaced apart from the guide head. The maximum outer diameter of the straightening sleeve is larger than the maximum outer diameter of the main body, and the straightening sleeve is constructed to be corroded by acid.

4. The well cleaning tool according to claim 1 or 2, characterized in that, It also includes, A release assembly, the release assembly comprising a first connector, a tensioning member, and a driving member; The first connector includes an elastic connecting portion located at its bottom, the elastic connecting portion being inserted into the body; The expansion member is installed inside the first connector to radially open the elastic connection portion, thereby locking the elastic connection portion with the main body; The driving member is used to push the expansion member to move axially, so as to drive the expansion member to separate from the first connecting member, thereby unlocking the elastic connection part from the main body.

5. The well cleaning tool according to claim 4, characterized in that, The elastic connection includes a limiting protrusion extending radially outward, and a limiting groove is formed inside the main body. The limiting protrusion is inserted into the limiting groove to lock the first connector to the main body.

6. The well cleaning tool according to claim 5, characterized in that, The release assembly also includes a second connector, which is installed on top of the first connector. The first connector has a first hole, and the tensioning member is installed in the first hole. The second connector has a second hole, and the first hole and the second hole are connected to form a first channel. The drive member is configured to fall along the first channel to pump to the tensioning member.

7. The well cleaning tool according to claim 6, characterized in that, The expansion member has an axially extending third hole, which is connected to the second hole; The third hole includes a large hole section and a small hole section that are connected to each other. The large hole section is located above the small hole section, and the diameter of the large hole section is larger than that of the small hole section. The outer diameter of the driving member is smaller than the inner diameter of the large hole section but larger than the inner diameter of the small hole section.

8. The well cleaning tool according to claim 7, characterized in that, The well-dredging tool achieves pressure build-up through a drive component and a small hole section, thereby driving the expansion member to move downwards.

9. The well cleaning tool according to claim 4, characterized in that, The expansion member is connected to the first connecting member via a shear pin, the shear pin being configured to break when the shear force it bears is greater than or equal to the first shear force, and the maximum pushing force of the driving member is greater than the first shear force.

10. The well cleaning tool according to claim 9, characterized in that, The expansion member is also equipped with a shearing ring for installing shear pins and fixing the expansion member to the first connecting member.

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