A multi-purpose fish falling and salvaging tool and fish falling and salvaging method

Abstract

This invention relates to a multi-functional fish retrieval tool and method. The retrieval tool includes: an upper connector, the upper end of which can be fixedly connected to a drill bit; a retrieval cylinder, the upper end of which is fixedly connected to the lower end of the upper connector, and the retrieval cylinder has multiple inverted windows; a female cone, fixed to the lower end of the retrieval cylinder, the female cone having a conical inner wall surface with internal threads; a milling shoe, fixedly connected to the lower end of the female cone, the milling shoe being cylindrical, and the inner diameter of the milling shoe being slightly larger than the inner diameter of the upper end of the female cone; and an anti-drop net, located inside the retrieval cylinder, the outer circumference of the anti-drop net being connected to the inner wall of the retrieval cylinder, the middle part of the anti-drop net allowing fish and debris to pass through, the middle part of the anti-drop net tilting upwards to fit with the outer wall of the fish or debris when the fish or debris passes through the middle part of the anti-drop net, and the anti-drop net remaining horizontal after the fish or debris has passed through. The multi-functional fish retrieval tool of the present invention can overcome the shortcomings of existing retrieval tools, such as high failure rate in retrieving deformed fish and easy drill jamming during milling.

Description

Technical Field

[0001] This invention relates to the field of oil and gas well fishing operations, specifically to a multi-functional fish retrieval and fish retrieval method. Background Technology

[0002] In oil, gas, and water well production, it is common to encounter situations where production tubing corrodes and breaks off, resulting in fish falling into the well. Conventional methods for dealing with corroded tubing strings include internal retrieval tools such as male cones and spears, and external retrieval tools such as retrieval tubes.

[0003] In actual production, it is common to encounter tubing that is severely corroded but still has a certain strength and is deformed at the top. Using conventional internal and external retrieval tools often results in low retrieval efficiency or retrieval failure. At the same time, because the fish has a certain strength, using traditional grinding and milling methods will result in low milling efficiency and generate a large amount of iron sheet, causing drill jamming accidents. Summary of the Invention

[0004] This invention provides an all-in-one fish retrieval tool that overcomes the shortcomings of existing retrieval tools, such as high failure rate in retrieving deformed fish and easy drill jamming during milling.

[0005] The multi-functional fish retrieval tool of the present invention includes:

[0006] The upper connector, the upper end of which can be fixedly connected to the drill bit;

[0007] The retrieval tube has its upper end fixedly connected to the lower end of the upper connector. The retrieval tube is provided with multiple inverted windows. Each inverted window is formed by partially penetrating and cutting through the wall of the retrieval tube. The lower end of each inverted window is integral with the wall of the retrieval tube, and the upper part is inclined inward into the retrieval tube at an angle of less than 90°. The windows formed by partially cutting through the wall of the retrieval tube are sealed by a sealing plate.

[0008] A female cone is fixed to the lower end of the retrieval cylinder. The female cone has a conical inner wall surface. The inner diameter of the lower end of the female cone is larger than the inner diameter of the upper end, and its inner wall surface has internal threads.

[0009] A milling shoe is fixedly connected to the lower end of the mother cone. The milling shoe is cylindrical, and its inner diameter is slightly larger than the inner diameter of the upper end of the mother cone.

[0010] An anti-drop net is located inside the retrieval tube. The outer circumference of the anti-drop net is connected to the inner wall of the retrieval tube. The middle part of the anti-drop net allows fish and debris to pass through. When fish and debris pass through the middle part of the anti-drop net, the middle part of the anti-drop net tilts upward to cooperate with the outer wall of the fish or debris. After the fish and debris pass through, the anti-drop net remains horizontal or tilts upward in the middle.

[0011] Preferably, the lower end face of the milling shoe is provided with a circulation groove, which connects the inside and outside of the milling shoe.

[0012] Preferably, the lower end face of the milling shoe is provided with two radially tangentially extending circulation grooves.

[0013] As a preferred option, multiple inverted windows are arranged in a spiral on the retrieval tube.

[0014] Preferably, the material of the sealing sheet is the same as that of the retrieval tube.

[0015] Preferably, the anti-drop net includes multiple anti-drop bars, one end of each anti-drop bar is fixed to the retrieval cylinder, and the other end is a free end.

[0016] Preferably, the anti-drop strip is a metal sheet, one end of which is connected to the retrieval tube by welding, and the other ends of multiple anti-drop strips intersect or overlap.

[0017] Preferably, the mother cone and the retrieval cylinder are integrated.

[0018] The present invention also provides a method for retrieval of fallen fish, comprising the following steps:

[0019] S1, fix the retrieval tool to the lower end of the drill bit, wherein the retrieval tool is the multi-in-one fish retrieval tool as described above;

[0020] S2, use the milling shoe of the retrieval tool to adjust the deformed part of the fish by aligning it with the upper part of the fish, and rotate the drill bit while lowering it during the adjustment.

[0021] S3, after the trimming is completed, rotate the drill bit in the opposite direction to make the fragments enter the retrieval tube and pass through the middle of the anti-drop net;

[0022] S4, rotate forward and lower the drill bit to allow the finished fish to enter the mother cone for knot making;

[0023] S5, continue to rotate and lower the drill bit so that the upper end of the finished fish passes through the mother cone, the anti-fall net and the area with the inverted window, and cooperates with the anti-fall net and the inverted window;

[0024] S6, stop rotating the drill bit, lift up the retrieval tool, and remove the fallen fish.

[0025] Compared with the prior art, the present invention has the following advantages: The multi-functional fish retrieval tool of the present invention can first mill irregular and strong fish to make their shape more regular, making it easier for the fish to enter the mother cone and increasing the probability of the fish entering the mother cone. When the retrieval tool descends, the internal thread of the mother cone can squeeze the outer wall of the fish to create a loop, thereby tightly grasping the fish and sending it upward into the retrieval tube. The anti-drop net allows larger fragments to pass through from the middle upwards and prevents them from falling downwards from the retrieval tube and causing the drill to jam. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of an all-in-one fish-catching tool according to an embodiment of the present invention, cut along a cross section passing through the axis.

[0027] Figure 2 This is a schematic diagram of the milling shoe of the multi-functional fish retrieval tool according to an embodiment of the present invention, viewed from below.

[0028] Figure Labels

[0029] 1. Connector;

[0030] 2. Salvage tube; 21. Inverted window; 22. Sealing plate;

[0031] 3 mother cones;

[0032] 4 milling shoe, 41 circulation groove;

[0033] 5. Prevents network drop. Detailed Implementation

[0034] This invention provides a multi-functional tool for retrieving fallen tubing from oil and gas wells. Most fallen tubing is tubing, and this invention is particularly suitable for retrieving tubing that has become deformed and corroded but still retains a certain degree of strength. Figure 1As shown, the salvage tool in this embodiment includes: an upper connector 1, a salvage cylinder 2, a female cone 3, a milling shoe 4, and an anti-drop net 5. The upper end of the upper connector 1 is fixedly connected to the drilling tool via threads, allowing the drilling tool to rotate with the entire salvage tool. The lower end of the upper connector 1 is fixedly connected to the upper end of the salvage cylinder 2 via threads. The female cone 3 is fixed to the lower end of the salvage cylinder 2. The female cone 3 has a conical inner wall surface, with the inner diameter of the lower end being larger than the inner diameter of the upper end, and its inner wall surface having internal threads. In this embodiment, the female cone 3 and the salvage cylinder 2 are integrally formed and made of metal. The milling shoe 4 is fixedly connected to the lower end of the mother cone 3. The milling shoe 4 is cylindrical, and the milling shoe 4, mother cone 3, retrieval cylinder 2, and upper connector 1 are coaxial. The inner diameter of the milling shoe 4 is slightly larger than the inner diameter of the upper end of the mother cone 3. The milling shoe 4 can trim deformed fish, making its shape more regular, and can ensure that the diameter of the fish trimmed by the milling shoe 4 is slightly larger than the minimum inner diameter of the mother cone 3. In this way, when the mother cone 3 descends, the internal thread of the mother cone 3 can squeeze the outer wall of the fish to create a thread, thereby tightly grasping the fish and sending it upward. The milling shoe 4 can also mill objects in the annulus between the fish and the well wall, removing objects that prevent the fish to be retrieved from entering the mother cone. The anti-fall net 5 is located inside the retrieval cylinder 2. The outer circumference of the anti-fall net 5 is connected to the inner wall of the retrieval cylinder 2. The middle section of the anti-fall net 5 allows fish and the milling shoe 4 to pass through the debris generated by the fish. When the fish and debris pass through the middle section of the anti-fall net 5, the middle section of the anti-fall net 5 tilts upward to fit against the outer wall of the fish or debris. After the fish and debris pass through, the anti-fall net 5 remains horizontal or tilts upward from the horizontal plane at an angle of 5°-30°. The anti-fall net 5 prevents the debris from falling downward. Here, "fragments" refers to pieces larger than debris.

[0035] The multi-functional fish retrieval tool of this invention can first mill irregular and strong fish to make their shape more regular, facilitating their entry into the mother cone 3 and increasing the probability of them entering the mother cone 3. The milling shoe 4 can also mill objects in the annular space between the fish and the well wall, removing objects that hinder the fish from entering the mother cone, which also increases the probability of the fish entering the mother cone 3. When the retrieval tool descends, the internal thread of the mother cone 3 can squeeze the outer wall of the fish to create a snap, thereby tightly grasping the fish and sending it upward into the retrieval cylinder 2. The anti-drop net 5 allows larger fragments to pass upward through its middle and prevents them from falling downward from the retrieval cylinder 2 and causing the drill bit to jam.

[0036] The lower end face of the milling shoe 4 is provided with a circulation groove 41, which connects the inside and outside of the milling shoe 4. When the milling shoe 4 mills the fish, the end face of the milling shoe 4 and the plane of the fish will form a fit, and the circulation groove 41 forms a channel between the two, allowing the drilling fluid to circulate better inside and outside the retrieval tube. The drilling fluid can return the milling debris to the well surface. Figure 2As shown, in this embodiment, the lower end face of the milling shoe 4 is provided with two radially extending and unidirectional circulation grooves 41.

[0037] like Figure 1 As shown, the retrieval tube 2 is provided with multiple inverted windows 21. Each inverted window 21 is formed by partially cutting through the wall of the retrieval tube 2. The lower end of each inverted window 21 is integral with the wall of the retrieval tube 2, while the upper part is inclined inwards towards the retrieval tube 2 at an angle less than 90°, preferably 30°-60°. The windows formed by partially cutting through the wall of the retrieval tube 2 are sealed by a sealing plate 22. In this embodiment, three inverted windows 21 are arranged in a spiral pattern on the retrieval tube 2, covering the entire circumference of the retrieval tube 2. This spiral pattern applies an upward force to the entire outer wall of the fallen fish. In this embodiment, the sealing plate 22 is made of the same material as the retrieval tube 2, namely metal.

[0038] The anti-fall net 5 includes multiple anti-fall strips, each with one end fixed to the retrieval tube 2 and the other end free. Each anti-fall strip is a metal sheet, with one end welded to the retrieval tube 2. The other ends of the multiple anti-fall strips intersect or overlap, or are close together to form holes with a diameter smaller than the outer diameter of the fish. When a fish enters the retrieval tube 2, the anti-fall strips tilt upwards, their other ends engaging with the fish. As the fish continues to move upwards above the anti-fall net 5, the anti-fall strips essentially return to their flat surface, preventing fragments from falling downwards. The anti-fall net 5 can be a single layer or multiple layers along the length of the retrieval tube.

[0039] In this embodiment, the female cone 3 and the retrieval cylinder 2 are integral, that is, a conical inner wall surface is formed at the lower end of the retrieval cylinder 2 and a thread is provided on the conical inner wall surface.

[0040] The present invention also provides a method for retrieval of fallen fish, comprising the following steps:

[0041] S1, fix the retrieval tool to the lower end of the drill bit, wherein the retrieval tool is the multi-in-one fish retrieval tool as described above;

[0042] S2, use the milling shoe 4 of the retrieval tool to adjust the deformed part of the fish above it, and rotate the drill bit while lowering it during the adjustment.

[0043] S3, after the trimming is completed, the drill bit is rotated in the opposite direction so that the liquid carries the fragments into the retrieval cylinder 2 and passes through the middle of the anti-fall net 5. Here, "reverse" means that the rotation direction of the drill bit after the trimming is completed is opposite to the rotation direction of the drill bit when the milling shoe 4 trims the fallen fish.

[0044] S4, rotate forward and lower the drill bit so that the finished fish falls into the mother cone 3 to make a knot;

[0045] S5, continue to rotate and lower the drill bit so that the upper end of the fish that has been trimmed passes through the mother cone 3, the anti-fall net 5 and the area with the inverted window 21, and cooperates with the anti-fall net 5 and the inverted window 21;

[0046] S6, stop rotating the drill bit, lift up the retrieval tool, and remove the fallen fish.

[0047] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Various modifications or equivalent substitutions made by those skilled in the art to the present invention within its spirit and scope of protection also fall within the scope of protection of the present invention.

Claims

1. A multi-functional fish-catching tool, characterized in that, include: The upper connector, the upper end of which can be fixedly connected to the drill bit; The retrieval tube has its upper end fixedly connected to the lower end of the upper connector. The retrieval tube is provided with multiple inverted windows. Each inverted window is formed by partially penetrating and cutting through the wall of the retrieval tube. The lower end of each inverted window is integral with the wall of the retrieval tube, and the upper part is inclined inward into the retrieval tube at an angle of less than 90°. The windows formed by partially cutting through the wall of the retrieval tube are sealed by a sealing plate. A female cone is fixed to the lower end of the retrieval cylinder. The female cone has a conical inner wall surface. The inner diameter of the lower end of the female cone is larger than the inner diameter of the upper end, and its inner wall surface has internal threads. A milling shoe is fixedly connected to the lower end of the mother cone. The milling shoe is cylindrical, and its inner diameter is slightly larger than the inner diameter of the upper end of the mother cone. An anti-drop net is located inside the retrieval tube. The outer circumference of the anti-drop net is connected to the inner wall of the retrieval tube. The middle part of the anti-drop net allows fish and debris to pass through. When fish and debris pass through the middle part of the anti-drop net, the middle part of the anti-drop net tilts upward to cooperate with the outer wall of the fish or debris. After the fish and debris pass through, the anti-drop net remains horizontal or tilts upward in the middle.

2. The salvage tool according to claim 1, characterized in that, The lower end face of the milling shoe is provided with a circulation groove, which connects the inside and outside of the milling shoe.

3. The salvage tool according to claim 2, characterized in that, The lower end face of the milling shoe is provided with two radially extending and unidirectional circulation grooves.

4. The salvage tool according to claim 1, characterized in that, Multiple inverted windows are arranged in a spiral on the retrieval tube.

5. The salvage tool according to claim 1, characterized in that, The material of the sealing plate is the same as that of the retrieval tube.

6. The salvage tool according to claim 1, characterized in that, The anti-drop net includes multiple anti-drop bars, one end of each anti-drop bar is fixed to the retrieval tube, and the other end is a free end.

7. The salvage tool according to claim 6, characterized in that, The anti-fall strip is a metal sheet, one end of which is connected to the retrieval tube by welding, and the other ends of multiple anti-fall strips intersect or overlap.

8. The salvage tool according to claim 1, characterized in that, The mother cone and the retrieval tube are integrated.

9. A method for retrieving fallen fish, characterized in that, Includes the following steps: S1, fix the retrieval tool to the lower end of the drill bit, wherein the retrieval tool is any one of the multi-in-one fish retrieval tools according to claims 1-8; S2, use the milling shoe of the retrieval tool to adjust the deformed part of the fish by aligning it with the upper part of the fish, and rotate the drill bit while lowering it during the adjustment. S3, after the trimming is completed, rotate the drill bit in the opposite direction to make the fragments enter the retrieval tube and pass through the middle of the anti-drop net; S4, rotate forward and lower the drill bit to allow the finished fish to enter the mother cone for knot making; S5, continue to rotate and lower the drill bit so that the upper end of the finished fish passes through the mother cone, the anti-fall net and the area with the inverted window, and cooperates with the anti-fall net and the inverted window; S6, stop rotating the drill bit, lift up the retrieval tool, and remove the fallen fish.

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