Retractable coiled tubing fallen object milling and fishing integrated tool

Abstract

The utility model relates to the field of casing milling, cutting and fishing after a coiled tubing falls into a well, in particular to a retreating type coiled tubing falling object casing milling and fishing integrated tool which comprises a cutting assembly, a fishing assembly, an upper connector and a transposition assembly. The cutting assembly and the fishing assembly are linearly connected together, the position changing assembly is connected above the fishing assembly, a position changing pin on a position changing outer cylinder is matched with a short groove or a long groove in a position changing mandrel by rotating the position changing outer cylinder of the position changing assembly, the fishing assembly is controlled to work, the shearing pin is arranged on the fishing assembly, and the shearing pin is arranged on the position changing outer cylinder. When necessary (cutting-off is conducted under the action of strong force), the cutting assembly is controlled to work, the coiled tubing on the inner side is cut off, the state of the integrated tool can be well adjusted to work according to actual requirements, and the integrated tool has the good using effect.

Description

Technical Field

[0001] The utility model relates to the field of milling, cutting and salvaging of a coiled tubing after it falls into a well, in particular to a retractable integrated tool for milling and salvaging fallen coiled tubing. Background Art

[0002] With the rapid development of shale gas, the frequency of coiled tubing (CT) used for sand flushing and unblocking shale gas wellbores has increased significantly. After volume fracturing, sand is produced during the flowback of the fracturing fluid in most shale gas wells, causing wellbore blockage. CT units are typically used to flush and unblock the blockage. Due to a combination of factors, such as formation pressure, flushing fluid properties, and flushing parameters, CT sand sticking often occurs. When unblocking is unsuccessful, the CT must be cut at the wellhead. To clear the wellbore, the CT must be lowered and retrieved.

[0003] The typical salvage operation involves untangling the fish through milling, then lowering a salvage tool to retrieve the entire fish. Alternatively, after partially untangling the fish through milling, the salvage tool is lowered to disassemble the fish and retrieve it in sections. Repeating the milling and salvaging process until the entire fish is recovered. After coiled tubing is cut at the wellhead, its length makes it difficult to completely untie it through a single milling operation, requiring external cutting to disassemble and retrieve the fish in sections.

[0004] After the existing milling, cutting and salvaging tools are put into the fish, they are only allowed to be lowered freely. When the fish is caught when it is pulled up, it cannot be released, thus limiting the free upward movement of the tool string. When using a turntable for milling construction, after the square drill rod is milled, the tool string cannot be lifted up to change single rods, so a top drive is required to smoothly realize the integration of the three functions of milling, cutting and salvaging. Even if a top drive is used for construction, during the period of drilling after the tool is put into the fish, if there is an obstruction in the middle of the single rod of the string, the drill string cannot be lifted up to sit on the hanging card, and the top drive cannot be connected back for milling, which limits the use of the tool. When abnormal parameters such as torque and pump pressure appear during the milling operation, the tool string cannot be moved upward, which is extremely unfavorable for judging and resolving the cause of the abnormal situation. For this reason, the utility model provides a retractable continuous oil pipe milling and salvage integrated tool. Utility Model Content

[0005] The utility model aims to solve the shortcomings of the prior art and proposes a retractable coiled tubing falling object milling and salvaging integrated tool.

[0006] In order to achieve the above-mentioned purpose, the utility model adopts the following technical solutions: a retractable coiled tubing falling object milling and salvaging integrated tool, comprising a cutting assembly, a salvaging assembly, and an upper joint;

[0007] The cutting assembly includes a cutting outer cylinder, the bottom of which is provided with an external threaded connection portion, and the inner side of which is provided with a blade and a push cylinder;

[0008] The salvage assembly includes a salvage outer cylinder, the bottom end of which is fixedly connected to the top end of the cutting outer cylinder, the inner side of which is fixedly connected to a slip seat via a shear pin, and a petal slip is provided on the inner side of the salvage outer cylinder and above the slip seat;

[0009] The transposition assembly also includes a transposition outer cylinder, a transposition core shaft, and a transposition pin. The bottom end of the transposition outer cylinder is fixedly connected to the top end of the salvage outer cylinder, the top end of the transposition outer cylinder is fixedly connected to the upper joint, the top of the upper joint has an internal threaded connection part, the transposition core shaft is fixed to the side of the transposition outer cylinder, and the transposition core shaft is along the radial direction of the transposition outer cylinder, and the transposition core shaft has a part located on the inner side of the transposition outer cylinder, the transposition core shaft is located on the inner side of the transposition outer cylinder, and the side of the transposition core shaft begins to have short grooves, long grooves and spiral grooves connecting the short grooves and the long grooves distributed along its own axial direction, and the part of the transposition pin located on the inner side of the transposition outer cylinder is inserted into the short groove or the long groove.

[0010] As a further description of the above technical solution:

[0011] An inner convex cone portion is provided on the inner side of the cutting outer cylinder for limiting the downward sliding of the blade, and the cutting outer cylinder and the push cylinder are matched with each other in a plum blossom-shaped cross section.

[0012] As a further description of the above technical solution:

[0013] A conical inclined surface is provided at the inner side and the top end of the slip seat, and the conical inclined surface corresponds to the outer side and the bottom end of the petal slip.

[0014] As a further description of the above technical solution:

[0015] The transposition pins are provided in two groups and are symmetrical along the axial section of the transposition outer cylinder.

[0016] As a further description of the above technical solution:

[0017] A threaded hole is provided on the side of the transposition outer cylinder. The transposition pin comprises a threaded section and a cylindrical section. The threaded section cooperates with the threaded hole, and the cylindrical section is located inside the transposition outer cylinder.

[0018] The utility model has the following beneficial effects:

[0019] 1. Compared with the existing technology, this retractable integrated tool for milling and salvaging fallen coiled tubing linearly connects the cutting assembly and the salvaging assembly, and connects the transposition assembly above the salvaging assembly. By rotating the transposition outer cylinder of the transposition assembly, the transposition pin on the transposition outer cylinder cooperates with the short groove or long groove on the transposition core shaft to control the operation of the salvage assembly. The shear pin is provided on the salvage assembly, which can control the operation of the cutting assembly when necessary (cutting under strong force) to cut the inner coiled tubing. This integrated tool can adjust its working state according to actual needs and has a good use effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is an overall cross-sectional view of a retractable coiled tubing milling and salvaging integrated tool proposed in the utility model;

[0021] Figure 2 This is a schematic cross-sectional view of a blade of a retractable coiled tubing falling object milling and salvaging integrated tool proposed in the utility model;

[0022] Figure 3 This is a front view of the transposition mandrel of a retractable coiled tubing falling object milling and salvaging integrated tool proposed in the utility model;

[0023] Figure 4 This is a partially flattened schematic diagram of the transposition mandrel of a retractable coiled tubing falling object milling and salvaging integrated tool proposed in the utility model.

[0024] Legend:

[0025] 1. Cutting outer cylinder; 2. Blade; 3. Push cylinder; 4. Salvage outer cylinder; 5. Slip seat; 6. Split slip; 7. Shear pin; 8. Transposition mandrel; 81. Short groove; 82. Spiral groove; 83. Long groove; 9. Transposition outer cylinder; 10. Transposition pin; 11. Upper joint. DETAILED DESCRIPTION

[0026] Reference Figures 1-4 The utility model provides a retractable coiled tubing falling object milling and salvaging integrated tool, which includes a cutting assembly: a cutting outer cylinder 1, a blade 2 and a push cylinder 3; a salvaging assembly: a salvaging outer cylinder 4, a slip seat 5, a petal slip 6, a shear pin 7 and a transposition core shaft 8; a transposition assembly: a transposition outer cylinder 9, a transposition pin 10 and an upper joint 11.

[0027] The cutting assembly includes a cutting outer cylinder 1, the bottom of which has an external thread connection portion, which is used to connect a sleeve milling shoe and is used during sleeve milling operations. A blade 2 and a push cylinder 3 are provided on the inner side of the cutting outer cylinder 1.

[0028] An inner convex cone is provided on the inner side of the cutting outer cylinder 1 to limit the blade 2 from sliding downward. Specifically, the cutting outer cylinder 1 is a cylinder with three straight holes and two tapered holes. The two ends of the middle straight hole are tapered holes. The cutting outer cylinder 1 and the push cylinder 3 have a plum blossom-shaped cross-section.

[0029] It can achieve that the push cylinder 3 and the cutting outer cylinder 1 can only slide relative to each other and cannot rotate. When the push cylinder 3 moves relative to the blade 2, the inner convex cone limits the blade 2 from sliding downward. At this time, the blade 2 is squeezed and the inner claws clamp the coiled tubing, which can be used to cut the coiled tubing.

[0030] The salvage assembly includes a salvage outer tube 4, the bottom end of which is fixedly connected to the top end of the cutting outer tube 1, the inner side of the salvage outer tube 4 is fixedly connected to a slip seat 5 through a shear pin 7, and a petal slip 6 is provided on the inner side of the salvage outer tube 4 and above the slip seat 5.

[0031] A tapered surface is provided at the inner side and top end of the slip seat 5 , and the tapered surface corresponds to the outer side and bottom end of the petal slip 6 .

[0032] When the split slip 6 is pushed downward, its bottom end cooperates with the top end of the slip seat 5 and squeezes each other, so that the claws of the split slip 6 clamp the coiled tubing for salvage. When necessary, the outer cylinder 4 can be lifted and salvaged to shear the shear pin 7 under strong force.

[0033] It also includes a transposition assembly, which has a transposition outer cylinder 9, a transposition core shaft 8, and a transposition pin 10. The bottom end of the transposition outer cylinder 9 is fixedly connected to the top end of the salvage outer cylinder 4, and the top end of the transposition outer cylinder 9 is fixedly connected to the upper joint 11. The top of the upper joint 11 has an internal threaded connection part, which is used to connect the casing milling pipe. The transposition core shaft 8 is fixed to the side of the transposition outer cylinder 9, and the transposition core shaft 8 is along the radial direction of the transposition outer cylinder 9, and the transposition core shaft 8 has a part located on the inner side of the transposition outer cylinder 9. The transposition core shaft 8 is located on the inner side of the transposition outer cylinder 9. The side of the transposition core shaft 8 begins to have short grooves 81 and long grooves 83 distributed along its own axial direction, and a spiral groove 82 connecting the short grooves 81 and the long grooves 83. The part of the transposition pin 10 located on the inner side of the transposition outer cylinder 9 is inserted into the short groove 81 or the long groove 83.

[0034] The user can realize the conversion of the transposition pin 10 between the short slot 81 and the long slot 83 by controlling the transposition outer cylinder 9 up and down and rotating it at a suitable height.

[0035] Specifically, the cutting outer cylinder 1 is a cylinder provided with three straight holes and two tapered holes, and the cross section of the middle straight hole is plum blossom-shaped.

[0036] The blade 2 is a rotating body with a T-shaped cross section. A plurality of non-through grooves are provided from the thick-walled end to the thin-walled end. Both ends of the outer wall protrusion are conical surfaces of a certain taper. The inner wall protrusion corresponds to the midpoint of the outer cylindrical generatrix at the thick wall, and the cross section of the inner wall protrusion is triangular.

[0037] The push cylinder 3 is a cylinder with a stepped hole, one end face of which is an oblique cone surface and the other end face is a plane surface, and an inner spline groove is provided on the inner wall of the small hole.

[0038] The salvage outer cylinder 4 is a cylinder with two sections of stepped straight holes, with internal and external connecting threads respectively provided at both ends, and a threaded through hole provided on the cylinder wall near the external thread end.

[0039] The slip seat 5 is a cylinder with a straight hole and a tapered hole, and the end faces at both ends are flat. The cross section of the straight hole section is plum blossom-shaped, and the outer wall of the straight hole section is provided with a blind hole.

[0040] The split slip 6 is a hollow, P-shaped rotating body with multiple non-through grooves extending from the thick-walled end to the thin-walled end. The thick-walled end has a tapered outer surface, while the inner cylindrical surface of the thick-walled end is internally threaded. The inner cylindrical surface near the thin-walled end is also internally threaded.

[0041] The shear pin 7 has an external thread on one end and a cylindrical

[0042] The transposition core shaft 8 is a cylinder with a straight-through hole as the inner hole and an outer wall composed of three cylindrical surfaces with gradually decreasing diameters. The largest cylindrical surface of the outer wall is provided with a plurality of long and short alternating grooves along the center line direction, and then a spiral groove is provided from the middle of the short groove to the long groove. The largest cylindrical surface of the outer wall is provided with an external thread on the end side.

[0043] The transposed outer cylinder 9 is a cylinder, with internal and external connecting threads respectively provided at both ends, and a threaded through hole provided on the cylinder wall near the external thread end.

[0044] The transposition pin 10 has an external thread on one end and a cylindrical surface on the other end.

[0045] The upper joint 11 is a cylinder, with internal and external connecting threads respectively provided at both ends.

[0046] After installing the tool's indexing pin 10, the indexing mandrel 8 is rotated vertically and horizontally until the indexing pin 10 is positioned at the uppermost end of the short slot 81 of the indexing mandrel 8. The upper connector 11 is then connected, releasing the tool's split slips 6. The externally threaded end of the cutting outer barrel 1 is connected to the milling shoe, while the internally threaded upper connector 11 receives the milling tube. The milling tube length is selected by the operator.

[0047] Milling: The tool's repositioning pin 10 is placed in the short slot 81 of the repositioning mandrel 8 and lowered into the well. After the fish is in, the split slips 6 remain clamped to the coiled tubing, and the repositioning pin 10 remains at the lower starting point of the short slot 81, preventing the split slips 6 from contacting the slip holder 5. At this point, the tool and the coiled tubing are free, save for the slight clamping force of the split slips 6 themselves. The drill string can be rotated and lowered for milling. To change a single string during milling, the tool string is lifted, and the repositioning pin 10 ascends along the short slot 81 to the upper starting point. At this point, the split slips 6 remain separated from the slip holder 5, and the tool and the coiled tubing remain free, allowing further lifting to replace the single string.

[0048] Fishing: After achieving the desired casing milling, the tool string is slowly lifted while rotating. The indexing pin 10 enters the spiral groove 82 along the middle opening of the short groove 81 and finally enters the long groove 83. As the tool string continues to be lifted, the indexing pin 10 moves upward along the long groove 83, and the slip seat 5 follows it upward. The inner conical surface of the slip seat 5 contacts the outer conical surface of the split slip 6, and the split slip 6 contracts inward to clamp the coiled tubing, forcing the internal threads of the split slip 6 to embed into the outer wall of the coiled tubing, thereby firmly fixing the coiled tubing and achieving fishing.

[0049] Cutting: To perform cutting, the coiled tubing must first be captured (see the salvage procedure). After capture, the tubing is lifted to a desired level, causing the slip seat 5 to shear against the shear pins 7 on the salvage outer tube 4. As the lifting continues, the slip seat 5 descends relative to the tubing until it contacts the upper end of the push tube 3, pushing it further downward. The inner conical surface at the lower end of the push tube 3 and the inner conical surface of the cutting outer tube 1 respectively contact the upper and lower conical surfaces of the blade 2, forcing the blade 2 inward. The triangular protrusion on the inner wall of the blade 2 engages the tubing until it is severed.

[0050] Tool Release: To release the tool, lower and slowly rotate the tool string. As the split slips 6 clamp the coiled tubing, the transposition mandrel 8 is fixed in position. The transposition pin 10 enters the spiral groove 82 along the lower opening of the long groove 83 and ultimately enters the short groove 81. The tool string is then lifted, and the transposition pin 10 moves upward along the short groove 81 to the upper starting point. This drives the transposition mandrel 8 and the split slips 6 upward. Because the slip holder 5 has shear pins 7 that prevent it from moving upward with the split slips 6, further lifting causes the split slips 6 to disengage from the tapered surface of the slip holder 5, releasing the tool.

[0051] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A retractable coiled tubing milling and salvaging integrated tool, comprising a cutting assembly, a salvaging assembly, and an upper joint (11), characterized in that: The cutting assembly comprises a cutting outer cylinder (1), the bottom of the cutting outer cylinder (1) having an external threaded connection portion, and the inner side of the cutting outer cylinder (1) is provided with a blade (2) and a push cylinder (3); The salvage assembly comprises a salvage outer cylinder (4), the bottom end of the salvage outer cylinder (4) is fixedly connected to the top end of the cutting outer cylinder (1), the inner side of the salvage outer cylinder (4) is fixedly connected to a slip seat (5) via a shear pin (7), and a petal slip (6) is provided on the inner side of the salvage outer cylinder (4) and above the slip seat (5); The invention also comprises a transposition assembly, wherein the transposition assembly comprises a transposition outer cylinder (9), a transposition core shaft (8), and a transposition pin (10), wherein the bottom end of the transposition outer cylinder (9) is fixedly connected to the top end of the salvage outer cylinder (4), the top end of the transposition outer cylinder (9) is fixedly connected to an upper joint (11), the top of the upper joint (11) has an internal thread connection portion, the transposition core shaft (8) is fixed to the side of the transposition outer cylinder (9), and the transposition core shaft (8) is arranged along the transposition outer cylinder (9). The transposition core shaft (8) is arranged in a radial direction, and a portion of the transposition core shaft (8) is located on the inner side of the transposition outer cylinder (9). The transposition core shaft (8) is located on the inner side of the transposition outer cylinder (9). A short groove (81), a long groove (83) and a spiral groove (82) connecting the short groove (81) and the long groove (83) are arranged on the side of the transposition core shaft (8) along its own axial direction. The portion of the transposition pin (10) located on the inner side of the transposition outer cylinder (9) is inserted into the short groove (81) or the long groove (83).

2. The retractable coiled tubing milling and salvaging integrated tool according to claim 1, characterized in that: An inner convex cone portion for limiting the downward sliding of the blade (2) is provided on the inner side of the cutting outer cylinder (1), and the cutting outer cylinder (1) and the push cylinder (3) are matched in a plum blossom-shaped cross section.

3. The retractable coiled tubing milling and salvaging integrated tool according to claim 1, characterized in that: A conical surface is provided at the inner side and top end of the slip seat (5), and the conical surface corresponds to the outer side and bottom end of the split slip (6).

4. The retractable coiled tubing milling and salvaging integrated tool according to claim 1, characterized in that: The transposition pins (10) are provided in two groups and are symmetrical along the axial section of the transposition outer cylinder (9).

5. The retractable coiled tubing milling and salvaging integrated tool according to claim 4 is characterized by: A threaded hole is provided on the side of the transposition outer cylinder (9); the transposition pin (10) comprises a threaded section and a cylindrical section; the threaded section cooperates with the threaded hole; and the cylindrical section is located inside the transposition outer cylinder (9).

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