A fishing device and method for a downhole choke integrating internal and external fishing

Abstract

The present invention discloses a salvage device and method for a downhole choke that integrates internal and external salvage. The present invention relates to the technical field of salvaging a downhole choke to the ground. The device comprises a joint, a circular cylinder with an opening at the bottom of the joint being fixedly provided at the bottom, a center rod with an opening that extends downward through the circular cylinder being fixedly provided inside the circular cylinder and located on its top wall, and a aligning ball head being detachably connected to the extended end of the center rod; an inner salvage assembly for hooking the annular step surface inside the salvage neck being provided on the center rod and located on both the left and right sides thereof; and an outer salvage assembly for hooking the annular boss of the salvage neck being provided on both the left and right sides of the circular cylinder. The beneficial effects of the present invention are that the downhole choke can be successfully salvaged to the ground, greatly improving the efficiency of salvaging the downhole choke.

Description

Technical Field

[0001] The present invention relates to the technical field of salvaging a downhole choke to the ground, in particular to a salvaging device and method for a downhole choke integrating internal and external salvaging. Background Art

[0002] In the process of underground oil and gas production, the downhole choke is indispensable. The downhole choke 1 is firmly fixed in the wellbore 2 through the processes of anchoring mechanism positioning, sealing element isolation, etc. Figure 1 As shown, the installed downhole choke 1 can effectively reduce the downhole oil pressure and improve the liquid carrying capacity of the single well itself, thereby ensuring that the oil and gas in the well can be smoothly produced.

[0003] In order to facilitate workers to salvage the downhole choke 1 from the wellbore 2 to the ground (the purpose of salvaging the downhole choke 1 to the ground is to facilitate workers to clean the choke nozzle in the downhole choke 1), workers usually fix a fishing neck 3 on the top end of the downhole choke 1 before installing the downhole choke 1 into the wellbore 2. After the fishing neck 3 is installed, the downhole choke 1 with the fishing neck 3 is fixed in the wellbore 2. Figure 2 As shown; wherein the structure of the fishing neck 3 is as shown Figure 3~Figure 4 As shown, it includes a straight cylinder 4, an annular boss 5 fixed on the outer cylindrical surface of the upper end of the straight cylinder 4, an outer conical surface 6 is provided on the outer edge of the annular boss 5, an inner conical surface 7 is provided in the upper end of the straight cylinder 4, and an annular step surface 8 is provided on the inner wall of the middle part of the straight cylinder 4.

[0004] After the downhole choke 1 has been used for a period of time, workers use a salvage tool to salvage the downhole choke 1 to the ground in the following manner:

[0005] Sa, the top of the fishing tool 10 is hung on the head end of the wire 9 of the wire unwinding mechanism, and the fishing tool 10 is initially placed just above the wellbore 2, as shown in FIG. Figure 5 As shown, under the gravity of the salvage tool 10, the steel wire 9 is in a taut state; then the power part of the steel wire unwinding mechanism is controlled to rotate forward, the steel wire unwinding mechanism gradually unwinds the steel wire 9, and the salvage tool 10 gradually moves downward along the wellbore 2;

[0006] Sb. When the wire 9 of the wire unwinding mechanism has been unwound to a certain number of turns, the worker turns off the power part of the wire unwinding mechanism. At this time, the two locking blocks 11 on the salvage tool 10 are just outside the salvage neck 3. Figure 6 As shown; then, a pressurized fluid is introduced into the fishing tool 10 through a pressure pump. Under the pressure of the fluid, the two locking blocks 11 of the fishing tool 10 move toward the fishing neck 3 and then respectively hook onto the bottom surfaces of the left and right ends of the annular boss 5 of the fishing neck 3, as shown. Figure 7As shown;

[0007] Sc. The power part of the wire unwinding mechanism is controlled to reverse, and the wire unwinding reels in the wire 9. The wire 9 drives the fishing tool 10 to gradually move upward. The two locking blocks 11 of the fishing tool 10 lift the annular boss 5 upward, thereby driving the fishing neck 3 to move upward. The fishing neck 3 in turn drives the downhole choke 1 to move upward, thereby finally achieving the purpose of salvaging the downhole choke 1 to the ground.

[0008] However, although the cooperation between the existing fishing tool 10 and the wire unwinding mechanism can salvage the downhole choke 1 to the surface, the following technical defects still exist:

[0009] Since the outer wall of the downhole choke 1 is firmly attached to the wellbore 2, that is, the friction between the outer wall of the downhole choke 1 and the inner wall of the wellbore 2 is very large, therefore, when the two locking blocks 11 are in the process of lifting the annular boss 5 of the fishing neck 3 upward, the lifting force to overcome the friction between the outer wall of the downhole choke 1 and the wellbore 2 is all concentrated on the bottom surface of the annular boss 5, and the annular boss 5 has been corroded by the hydrogen sulfide gas in the well and has poor fracture resistance, resulting in the annular boss 5 of the fishing neck 3 being broken during the lifting process of the fishing neck 3, which in turn leads to the failure of fishing the downhole choke 1.

[0010] To solve this problem, the only way is to frequently adjust the position of the fishing tool 10 so that the two locking blocks 11 of the fishing tool 10 are clamped onto the unbroken portion of the annular boss 5, thereby fishing the downhole choke 1 to the surface. Although this method can successfully fish the downhole choke 1 to the surface, it requires multiple operations to fish the downhole choke 1 to the surface, which undoubtedly increases the fishing time of the downhole choke 1 and thus reduces the fishing efficiency of the downhole choke 1.

[0011] Therefore, there is an urgent need for a salvaging device and method that can successfully salvage the downhole choke to the ground and greatly improve the salvage efficiency of the downhole choke. Summary of the Invention

[0012] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a downhole choke salvaging device and method that can successfully salvage the downhole choke to the ground and greatly improve the downhole choke salvage efficiency, integrating internal and external salvage.

[0013] The objectives of the present invention are achieved through the following technical solutions: a fishing device for a downhole choke that integrates internal and external fishing, comprising a joint, a circular cylinder with an opening at the bottom fixed to the bottom of the joint, a center rod fixed inside the circular cylinder and on the top wall thereof with an opening that extends downward through the circular cylinder, an alignment ball head detachably connected to an extended end of the center rod, the diameter of the alignment ball head being equal to the inner diameter of the straight cylinder of the fishing neck;

[0014] An inner salvage assembly for hooking the annular step surface in the salvage neck is provided on the center rod and on both the left and right sides thereof. The inner salvage assembly on the left side includes a first base fixedly provided on the cylindrical surface of the center rod, a first polished rod fixedly provided on the right end surface of the first base, an inner slip that can move left and right is slidably sleeved on the first polished rod, and a first horizontal spring is sleeved on the first polished rod, and the first horizontal spring is respectively fixed on the first base and the inner slip;

[0015] A first guide block is fixedly provided on the upper end of the inner slip, and the first guide block is slidably mounted in the guide groove of the first base. A first hook block is fixedly provided on the outer side of the lower end of the inner slip, and a first conical surface is provided on the outer side of the first hook block.

[0016] An outer salvage assembly for hooking the annular boss of the salvage neck is provided in the circular cylinder and on both the left and right sides. The outer salvage assembly on the right side includes a second base fixed on the inner wall of the circular cylinder, a second polished rod fixed on the left end surface of the second base, an outer slip that can move left and right is slidably sleeved on the second polished rod, and a second horizontal spring is sleeved on the second polished rod. The second horizontal spring is respectively fixed on the second base and the outer slip.

[0017] A second guide block is fixedly provided on the upper end of the outer slip, and the second guide block is slidably installed in the guide groove of the second base. A second hook block is fixedly provided on the inner side of the lower end of the outer slip, and a second cone surface is provided on the inner side of the second hook block.

[0018] A lifting ring for connecting with a steel wire is fixedly provided on the top of the joint.

[0019] An external thread is provided on the cylindrical surface of the lower end of the center rod, and an internal thread hole is provided on the top surface of the alignment ball head. The internal thread hole of the alignment ball head is threadedly connected to the external thread of the center rod to be connected to the lower end of the center rod.

[0020] The first conical surface matches the inner conical surface of the fishing neck, and the second conical surface matches the outer conical surface of the fishing neck.

[0021] The inner slip, the first guide block and the first hook block located on the right side of the center rod are integrally formed; the outer slip, the second guide block and the second hook block located on the right side of the circular cylinder are integrally formed.

[0022] The two inner salvage assemblies are symmetrically arranged about the central rod, and the two outer salvage assemblies are symmetrically arranged about the central rod.

[0023] The joint, the circular cylinder and the center rod are coaxially arranged, and the outer diameter of the circular cylinder is smaller than the inner diameter of the wellbore.

[0024] A method for salvaging a downhole choke that integrates internal and external salvaging, comprising the following steps:

[0025] S1. Tie and secure the lifting ring of the salvage device to the head end of the steel wire of the wire unwinding mechanism, and initially lower the salvage device directly above the wellbore. Under the gravity of the joint, the circular cylinder, and the center rod of the salvage device, the steel wire is kept taut. Then, the power part of the steel wire unwinding mechanism is controlled to rotate forward, and the steel wire unwinding mechanism gradually unwinds the steel wire, and the salvage device gradually moves downward along the wellbore.

[0026] S2. As the fishing device continues to be lowered, the spherical surface of the alignment ball first contacts the inner conical surface of the fishing neck. Then, under the action of the gravity load of the joint, the circular cylinder and the center rod, the alignment ball passes downward through the inner conical surface and enters the fishing neck. At this time, the joint, the circular cylinder and the center rod are on the same vertical line as the fishing neck.

[0027] S3. As the salvaging device continues to be lowered, the first conical surfaces of the first hook blocks of the two inner salvaging assemblies contact the inner conical surface of the salvaging neck. Subsequently, under the action of the gravity load of the joint, the circular cylinder, and the center rod, the inner conical surface of the salvaging neck gradually pushes the first hook block inward, and the first hook block drives the inner slips to gradually move inward along the first polished rod, and the inner slips gradually compress the first horizontal spring. After the first hook block of the inner salvaging assembly passes downward through the inner conical surface of the salvaging neck, the first hook block, the inner slips, and the compressed first horizontal spring remain stationary in the horizontal direction.

[0028] S4. As the salvage apparatus continues to be lowered, the second conical surfaces of the second hooks of the two outer salvage assemblies come into contact with the outer conical surfaces of the annular bosses of the salvage necks. Subsequently, under the gravity load of the joint, the circular cylinder, and the center rod, the outer conical surfaces of the annular bosses gradually push the second hooks outward, which in turn drives the outer slips to gradually move outward along the second polished rod, and the outer slips gradually compress the second horizontal spring. After the second hook of the outer salvage assembly passes downward through the outer conical surfaces of the annular bosses, the second hook, the outer slips, and the compressed second horizontal spring remain stationary in the horizontal direction.

[0029] S5. As the fishing device continues to be lowered, the first hook of the inner fishing assembly just passes downward through the annular step surface inside the fishing neck. Under the elastic restoring force of the compressed first horizontal spring, the inner slip moves outward along the first polished rod, and the inner slip drives the first hook to move outward synchronously, so that the first hook moves to just below the annular step surface of the fishing neck.

[0030] At the same time, the second hook of the outer salvage assembly just passes downward through the annular boss of the salvage neck. Under the elastic restoring force of the second horizontal spring in a compressed state, the outer slip moves inward along the second polished rod, and the outer slip drives the second hook to move inward synchronously, so that the second hook moves to just below the annular boss of the salvage neck.

[0031] S6. Control the power part of the wire unwinding mechanism to reverse, so that the wire unwinding reverses the wire reeling, and the wire lifts the fishing device upward. At this time, the first hook of the inner fishing assembly applies part of the lifting force to the annular step surface of the fishing neck. At the same time, the second hook of the outer fishing assembly applies another part of the lifting force to the annular boss of the fishing neck, thereby driving the fishing neck upward. The fishing neck in turn drives the downhole choke upward, thereby finally achieving the purpose of salvaging the downhole choke to the ground.

[0032] The present invention has the following advantages: the downhole choke can be successfully salvaged to the ground, and the salvaging efficiency of the downhole choke is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic diagram of a downhole choke fixed in a wellbore;

[0034] Figure 2 A schematic diagram of a downhole choke with a fishing neck fixed in a wellbore;

[0035] Figure 3 It is a structural diagram of the salvage neck;

[0036] Figure 4 for Figure 3 The main cross-sectional diagram of

[0037] Figure 5 This is a schematic diagram of the prior art fishing tool being initially placed just above the wellbore;

[0038] Figure 6 This is a schematic diagram of a salvage tool in the prior art in which both locking blocks are located outside the salvage neck;

[0039] Figure 7 A schematic diagram of two locking blocks of a salvage tool being hooked onto the annular boss of a salvage neck;

[0040] Figure 8 It is a structural schematic diagram of the present invention;

[0041] Figure 9 for Figure 8 The main cross-sectional diagram of

[0042] Figure 10 This is a schematic diagram of the connection between the center rod and the alignment ball head;

[0043] Figure 11 It is a structural diagram of the inner salvage assembly on the left;

[0044] Figure 12 for Figure 11 Schematic diagram of the connection between the first guide block, the first hook block and the inner slip;

[0045] Figure 13 for Figure 12 The main cross-sectional diagram of

[0046] Figure 14 The schematic diagram of the structure of the outer salvage assembly on the right;

[0047] Figure 15 for Figure 14 Schematic diagram of the connection between the second guide block, the second hook block and the outer slip;

[0048] Figure 16 for Figure 15 The main cross-sectional diagram of

[0049] Figure 17 A schematic diagram showing the initial placement of the salvage device directly above the wellbore;

[0050] Figure 18 Schematic diagram of the ball head passing downward through the inner conical surface and entering the fishing neck for alignment;

[0051] Figure 19 Schematic diagram showing that the first conical surfaces of the first hook blocks of the two inner fishing assemblies are in contact with the inner conical surface of the fishing neck;

[0052] Figure 20 A schematic diagram of the first hook of the inner fishing assembly passing downward through the inner conical surface of the fishing neck;

[0053] Figure 21 Schematic diagram showing that the second conical surfaces of the second hook blocks of the two outer salvage assemblies are in contact with the outer conical surface of the annular boss of the salvage neck;

[0054] Figure 22 A schematic diagram of the second hook of the outer fishing assembly passing downward through the outer conical surface of the annular boss of the fishing neck;

[0055] Figure 23 A schematic diagram of the first hook of the inner fishing assembly passing downward through the annular step surface inside the fishing neck;

[0056] Figure 24 Schematic diagram of the first hook moving to the position just below the annular step surface of the fishing neck;

[0057] In the picture:

[0058] 1- downhole choke, 2- wellbore, 3- fishing neck, 4- straight cylinder, 5- annular boss, 6- outer conical surface, 7- inner conical surface, 8- annular step surface, 9- steel wire, 10- fishing tool, 11- locking block;

[0059] 12- joint, 13- circular cylinder, 14- center rod, 15- aligning ball head;

[0060] 16- inner salvage assembly, 17- first base, 18- first polished rod, 19- inside slips, 20- first horizontal spring, 21- first guide block, 22- first hook block, 23- first cone;

[0061] 24-external salvage assembly, 25-second base, 26-second polished rod, 27-outer slip, 28-second horizontal spring, 29-second guide block, 30-second hook block, 31-second cone, 32-lifting ring. DETAILED DESCRIPTION

[0062] The present invention will be further described below with reference to the accompanying drawings, and the protection scope of the present invention is not limited to the following:

[0063] like Figures 8 to 16 As shown, a salvage device for a downhole choke that integrates internal and external salvage is shown. It includes a joint 12, the top of which is fixedly provided with a lifting ring 32 for connecting to a steel wire, the bottom of which is fixedly provided with a circular cylinder 13 with an opening at the bottom, a center rod 14 with an opening extending downward through the circular cylinder 13 and fixedly provided on its top wall, the extended end of the center rod 14 being detachably connected to a aligning ball head 15, the diameter of which is equal to the inner diameter of the straight cylinder 4 of the salvage neck 3; the joint 12, the circular cylinder 13, and the center rod 14 are coaxially arranged, the outer diameter of the circular cylinder 13 being smaller than the inner diameter of the wellbore 2. The cylindrical surface of the lower end of the center rod 14 is provided with an external thread, and the top surface of the aligning ball head 15 is provided with an internal threaded hole, the internal threaded hole of the aligning ball head 15 being threadedly connected to the external thread of the center rod 14 to connect to the lower end of the center rod 14.

[0064] An inner salvage assembly 16 for hooking the annular step surface 8 in the salvage neck 3 is provided on the center rod 14 and on its left and right sides. The two inner salvage assemblies 16 are symmetrically arranged about the center rod 14. The inner salvage assembly 16 on the left side includes a first base 17 fixedly arranged on the cylindrical surface of the center rod 14, a first polished rod 18 fixedly arranged on the right end surface of the first base 17, an inner slip 19 that can move left and right is slidably sleeved on the first polished rod 18, a first horizontal spring 20 is sleeved on the first polished rod 18, and the first horizontal spring 20 is respectively fixed on the first base 17 and the inner slip 19; a first guide block 21 is fixedly provided on the upper end of the inner slip 19, and the first guide block 21 is slidably installed in the guide groove of the first base 17, a first hook block 22 is fixedly provided on the outer side of the lower end of the inner slip 19, and a first cone surface 23 is opened on the outer side of the first hook block 22;

[0065] An outer salvage assembly 24 for hooking the annular boss 5 of the salvage neck 3 is provided inside the circular cylinder 13 and on both the left and right sides. The two outer salvage assemblies 24 are symmetrically arranged about the center rod 14. The outer salvage assembly 24 on the right side includes a second base 25 fixedly provided on the inner wall of the circular cylinder 13, a second polished rod 26 fixedly provided on the left end surface of the second base 25, an outer slip 27 that can move left and right is slidably sleeved on the second polished rod 26, a second horizontal spring 28 is sleeved on the second polished rod 26, and the second horizontal spring 28 is respectively fixed on the second base 25 and the outer slip 27; a second guide block 29 is fixedly provided on the upper end of the outer slip 27, and the second guide block 29 is slidably installed in the guide groove of the second base 25, a second hook block 30 is fixedly provided on the inner side of the lower end of the outer slip 27, and a second cone surface 31 is provided on the inner side of the second hook block 30.

[0066] The first tapered surface 23 mates with the inner tapered surface 7 of the fishing neck 3, and the second tapered surface 31 mates with the outer tapered surface 6 of the fishing neck 3. The inner slip 19, first guide block 21, and first hook block 22 on the right side of the center rod 14 are integrally formed; the outer slip 27, second guide block 29, and second hook block 30 on the right side of the circular cylinder 13 are integrally formed.

[0067] A method for salvaging a downhole choke that integrates internal and external salvaging, comprising the following steps:

[0068] S1, the lifting ring 32 of the salvage device is tied and fixed to the head end of the steel wire 9 of the steel wire unwinding mechanism, and the salvage device is initially placed just above the wellbore 2, as shown in FIG. Figure 17 As shown, under the weight of the joint 12, the circular cylinder 13 and the center rod 14 of the salvage device, the steel wire 9 is in a taut state; then the power part of the steel wire unwinding mechanism is controlled to rotate forward, and the steel wire unwinding mechanism gradually unwinds the steel wire 9, and the salvage device gradually moves downward along the wellbore 2;

[0069] S2. As the salvage device continues to be lowered, the spherical surface of the alignment ball head 15 first contacts the inner conical surface 7 of the salvage neck 3. Then, under the action of the gravity load of the joint 12, the circular cylinder 13 and the center rod 14, the alignment ball head 15 passes downward through the inner conical surface 7 and enters the salvage neck 3. Figure 18 As shown, at this time, the joint 12, the circular cylinder 13, the center rod 14 and the fishing neck 3 are on the same vertical line;

[0070] S3. As the salvage device continues to be lowered, the first conical surfaces 23 of the first hooks 22 of the two inner salvage components 16 are in contact with the inner conical surface 7 of the salvage neck 3. Figure 19 As shown, then under the action of the gravity load of the joint 12, the circular cylinder 13 and the center rod 14, the inner conical surface 7 of the fishing neck 3 gradually pushes the first hook block 22 inward, and the first hook block 22 drives the inner slip 19 to gradually move inward along the first polished rod 18, and the inner slip 19 gradually compresses the first horizontal spring 20. The movement direction of the inner slip 19 is as shown in FIG. Figure 19 When the first hook block 22 of the inner fishing assembly 16 passes downward through the inner conical surface 7 of the fishing neck 3, as shown in the solid arrow; Figure 20 As shown, the first hook 22, the inner slip 19 and the first horizontal spring 20 in a compressed state are all kept stationary in the horizontal direction;

[0071] S4. As the salvage device continues to be lowered, the second conical surfaces 31 of the second hooks 30 of the two outer salvage components 24 are in contact with the outer conical surface 6 of the annular boss 5 of the salvage neck 3. Figure 21 As shown, then under the action of the gravity load of the joint 12, the circular cylinder 13 and the center rod 14, the outer conical surface 6 of the annular boss 5 gradually pushes the second hook block 30 outward, and the second hook block 30 drives the outer slip 27 to gradually move outward along the second polished rod 26, and the outer slip 27 gradually compresses the second horizontal spring 28. The movement direction of the outer slip 27 is as shown in FIG. Figure 21 When the second hook block 30 of the outer salvage assembly 24 passes downward through the outer conical surface 6 of the annular boss 5, as shown in the hollow arrow; Figure 22 As shown, the second hook block 30, the outer slip 27 and the second horizontal spring 28 in a compressed state are all kept stationary in the horizontal direction;

[0072] S5. As the salvaging device continues to be lowered, the first hook block 22 of the inner salvaging assembly 16 just passes downward through the annular step surface 8 in the salvaging neck 3. Figure 23 As shown, under the elastic restoring force of the first horizontal spring 20 in the compressed state, the inner slip 19 moves outward along the first polished rod 18, and the inner slip 19 drives the first hook block 22 to move outward synchronously. The movement direction of the first hook block 22 is as shown in FIG. Figure 23As shown by the solid arrow in the middle, the first hook block 22 moves to the position just below the annular step surface 8 of the fishing neck 3, as shown in FIG. Figure 24 As shown;

[0073] At the same time, the second hook block 30 of the outer fishing assembly 24 also just passes downward through the annular boss 5 of the fishing neck 3. Figure 23 As shown, under the elastic restoring force of the second horizontal spring 28 in the compressed state, the outer slip 27 moves inward along the second polished rod 26, and the outer slip 27 drives the second hook block 30 to move inward synchronously. The movement direction of the second hook block 30 is as shown in FIG. Figure 23 As shown by the hollow arrow, the second hook block 30 moves to the position just below the annular boss 5 of the fishing neck 3, as shown in FIG. Figure 24 As shown;

[0074] S6. The power part of the wire unwinding mechanism is controlled to reverse, and the wire unwinding reels in the wire 9. The wire 9 lifts the fishing device upward. At this time, the first hook 22 of the inner fishing assembly 16 applies part of the lifting force to the annular step surface 8 of the fishing neck 3. At the same time, the second hook 30 of the outer fishing assembly 24 applies another part of the lifting force to the annular boss 5 of the fishing neck 3, thereby driving the fishing neck 3 to move upward. The fishing neck 3 in turn drives the downhole choke 1 to move upward, thereby finally achieving the purpose of salvaging the downhole choke 1 to the ground.

[0075] Among them, from steps S3 to S5, under the action of the gravity load of the joint 12, the circular cylinder 13 and the center rod 14, the first hook block 22 of the inner fishing assembly 16 is adaptively moved to just below the annular step surface 8 of the fishing neck 3, and at the same time, the second hook block 30 of the outer fishing assembly 24 is adaptively moved to just below the annular boss 5 of the fishing neck 3; then in step S6, during the process of lifting the downhole choke 1, the first hook block 22 of the inner fishing assembly 16 applies part of the lifting force to the annular step surface 8 of the fishing neck 3, and at the same time, the second hook block 30 of the outer fishing assembly 24 applies another part of the lifting force to the annular boss 5 of the fishing neck 3. That is to say, the lifting force that overcomes the friction between the outer wall of the downhole choke 1 and the wellbore 2 is distributed not only on the annular boss 5 of the fishing neck 3, but also on the annular step surface 8 of the fishing neck 3. Compared with the method of using Figures 5 to 7 The salvage method shown does not concentrate all the lifting force to overcome the friction between the outer wall of the downhole choke 1 and the wellbore 2 on the annular boss 5, thereby effectively avoiding the annular boss 5 corroded by hydrogen sulfide gas from breaking during the lifting process, thereby ensuring that the downhole choke 1 is successfully salvaged to the ground.

[0076] In addition, since the annular boss 5 of the fishing neck 3 will not break during the fishing process, compared with the Figures 5 to 7The salvaging method shown does not require frequent adjustment of the position of the salvage assembly for salvage, and can salvage the downhole choke 1 to the ground in one go, thereby greatly shortening the salvage time of the downhole choke 1 and greatly improving the salvage efficiency of the downhole choke 1.

Claims

1. A fishing device for a downhole choke that integrates internal and external fishing, characterized by: It comprises a joint (12), a circular cylinder (13) with an opening at the bottom of the joint (12), a central rod (14) with an opening penetrating downward through the circular cylinder (13) fixedly provided in the circular cylinder (13) and on the top wall thereof, an alignment ball head (15) is detachably connected to an extended end of the central rod (14), and the diameter of the alignment ball head (15) is equal to the inner diameter of the straight cylinder (4) of the fishing neck (3); An inner salvage assembly (16) for hooking the annular step surface (8) in the salvage neck (3) is provided on the center rod (14) and on both the left and right sides thereof. The inner salvage assembly (16) on the left side includes a first base (17) fixed on the cylindrical surface of the center rod (14), a first polished rod (18) fixed on the right end surface of the first base (17), an inner slip (19) that can move left and right is slidably sleeved on the first polished rod (18), a first horizontal spring (20) is sleeved on the first polished rod (18), and the first horizontal spring (20) is fixed on the first base (17) and the inner slip (19), respectively; A first guide block (21) is fixedly provided at the upper end of the inner slip (19), and the first guide block (21) is slidably mounted in the guide groove of the first base (17). A first hook block (22) is fixedly provided at the outer side of the lower end of the inner slip (19), and a first conical surface (23) is provided at the outer side of the first hook block (22); An outer salvage assembly (24) for hooking the annular boss (5) of the salvage neck (3) is provided inside the circular cylinder (13) and on both the left and right sides thereof. The outer salvage assembly (24) on the right side comprises a second base (25) fixedly provided on the inner wall of the circular cylinder (13), a second polished rod (26) fixedly provided on the left end surface of the second base (25), an outer slip (27) movable leftward and rightward is slidably sleeved on the second polished rod (26), a second horizontal spring (28) is sleeved on the second polished rod (26), and the second horizontal spring (28) is fixedly provided on the second base (25) and the outer slip (27), respectively. A second guide block (29) is fixedly provided at the upper end of the outer cava (27), and the second guide block (29) is slidably mounted in the guide groove of the second base (25). A second hook block (30) is fixedly provided on the inner side of the lower end of the outer cava (27), and a second conical surface (31) is provided on the inner side of the second hook block (30); The two inner salvage assemblies (16) are symmetrically arranged about the central rod (14), and the two outer salvage assemblies (24) are symmetrically arranged about the central rod (14).

2. The fishing device for a downhole choke integrating internal and external fishing according to claim 1, characterized in that: A lifting ring (32) for connecting to a steel wire is fixedly provided on the top of the joint (12).

3. The fishing device for a downhole choke integrating internal and external fishing according to claim 2, characterized in that: An external thread is provided on the cylindrical surface of the lower end of the center rod (14), and an internal thread hole is provided on the top surface of the alignment ball head (15). The internal thread hole of the alignment ball head (15) is threadedly connected to the external thread of the center rod (14) to be connected to the lower end of the center rod (14).

4. The fishing device for a downhole choke integrating internal and external fishing according to claim 3, characterized in that: The first conical surface (23) cooperates with the inner conical surface (7) of the salvage neck (3), and the second conical surface (31) cooperates with the outer conical surface (6) of the salvage neck (3).

5. The fishing device for a downhole choke integrating internal and external fishing according to claim 4, characterized in that: The inner slip (19), the first guide block (21) and the first hook block (22) located on the right side of the center rod (14) are integrally formed; the outer slip (27), the second guide block (29) and the second hook block (30) located on the right side of the circular cylinder (13) are integrally formed.

6. The fishing device for a downhole choke integrating internal and external fishing according to claim 5, characterized in that: The joint (12), the circular cylinder (13) and the center rod (14) are coaxially arranged, and the outer diameter of the circular cylinder (13) is smaller than the inner diameter of the wellbore (2).

7. A method for salvaging a downhole choke integrating internal and external salvage, using the salvaging device for a downhole choke integrating internal and external salvage according to claim 6, characterized in that: It includes the following steps: S1. Tie and fix the lifting ring (32) of the salvage device to the head end of the steel wire (9) of the steel wire unwinding mechanism, and initially place the salvage device just above the wellbore (2). Under the gravity of the joint (12), the circular cylinder (13) and the center rod (14) of the salvage device, the steel wire (9) is in a taut state; then control the power part of the steel wire unwinding mechanism to rotate forward, and the steel wire unwinding mechanism gradually unwinds the steel wire (9), and the salvage device gradually moves downward along the wellbore (2); S2. As the salvage device continues to be lowered, the spherical surface of the alignment ball head (15) first comes into initial contact with the inner conical surface (7) of the salvage neck (3). Then, under the action of the gravity load of the joint (12), the circular cylinder (13) and the center rod (14), the alignment ball head (15) passes through the inner conical surface (7) downward and enters the salvage neck (3). At this time, the joint (12), the circular cylinder (13), the center rod (14) and the salvage neck (3) are on the same vertical line; S3. As the salvaging device continues to be lowered, the first conical surfaces (23) of the first hook blocks (22) of the two inner salvaging components (16) are in contact with the inner conical surface (7) of the salvaging neck (3). Subsequently, under the action of the gravity load of the joint (12), the circular cylinder (13) and the center rod (14), the inner conical surface (7) of the salvaging neck (3) gradually pushes the first hook block (22) inward, and the first hook block (22) drives the inner slip (19) to move gradually inward along the first light rod (18), and the inner slip (19) gradually compresses the first horizontal spring (20); after the first hook block (22) of the inner salvaging component (16) passes downward through the inner conical surface (7) of the salvaging neck (3), the first hook block (22), the inner slip (19) and the first horizontal spring (20) in the compressed state all remain stationary in the horizontal direction; S4. As the salvaging device continues to be lowered, the second conical surfaces (31) of the second hook blocks (30) of the two outer salvaging components (24) are in contact with the outer conical surface (6) of the annular boss (5) of the salvaging neck (3). Subsequently, under the action of the gravity load of the joint (12), the circular cylinder (13) and the center rod (14), the outer conical surface (6) of the annular boss (5) gradually pushes the second hook block (30) outward, and the second hook block (30) drives the outer slip (27) to gradually move outward along the second polished rod (26), and the outer slip (27) gradually compresses the second horizontal spring (28); after the second hook block (30) of the outer salvaging component (24) passes downward through the outer conical surface (6) of the annular boss (5), the second hook block (30), the outer slip (27) and the second horizontal spring (28) in the compressed state all remain stationary in the horizontal direction; S5. As the salvaging device continues to be lowered, the first hook block (22) of the inner salvaging assembly (16) just passes downward through the annular step surface (8) inside the salvaging neck (3). Under the elastic restoring force of the first horizontal spring (20) in a compressed state, the inner slip (19) moves outward along the first polished rod (18), and the inner slip (19) drives the first hook block (22) to move outward synchronously, so that the first hook block (22) moves to just below the annular step surface (8) of the salvaging neck (3); At the same time, the second hook block (30) of the outer salvage assembly (24) also just passes downward through the annular boss (5) of the salvage neck (3), and under the elastic restoring force of the second horizontal spring (28) in the compressed state, the outer cava (27) moves inward along the second polished rod (26), and the outer cava (27) drives the second hook block (30) to move inward synchronously, so that the second hook block (30) moves to just below the annular boss (5) of the salvage neck (3); S6. The power part of the wire unwinding mechanism is controlled to reverse, and the wire unwinding reels the wire (9). The wire (9) lifts the salvage device upward. At this time, the first hook block (22) of the inner salvage assembly (16) applies a part of the lifting force to the annular step surface (8) of the salvage neck (3). At the same time, the second hook block (30) of the outer salvage assembly (24) applies another part of the lifting force to the annular boss (5) of the salvage neck (3), thereby driving the salvage neck (3) to move upward. The salvage neck (3) in turn drives the downhole choke (1) to move upward, thereby finally achieving the purpose of salvaging the downhole choke (1) to the ground.

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