High-strength fishing spear

Abstract

The utility model discloses a high-strength fishing spear which comprises an upper connector, and a spring sleeve, a slip, a piston extending cylinder, a piston and a guide cone are sequentially arranged on the upper connector. A spring is arranged between the upper joint and the spring sleeve; a plurality of key grooves which are evenly distributed in the circumferential direction are formed in the middle of a spear rod of the upper connector, the slips are embedded into the key grooves, and the key grooves are meshed with the slips through slope steps. The two ends of the slip are embedded into the spring sleeve and the piston extending cylinder respectively, and the piston extending cylinder is connected with the piston through threads. One end of the guide cone abuts against the piston, and the other end is in threaded connection with the upper connector. And an adjusting screw is also embedded into the tail end of the guide cone. The fishing tool can be used for fishing falling objects with inner holes, such as drill rods, oil pipes, casing pipes, liner pipes, packers, water distributors, bottom-hole regulators and the like, and can be used for carrying out vibration jam releasing and reverse reversing operation on the clamped falling objects. And under the condition that the underground fallen objects cannot be lifted out, the fallen objects can be separated in a mechanical manner and a hydraulic manner, so that the safety of the salvage pipe column is ensured.

Description

Technical Field

[0001] The utility model relates to the technical field of well completion and well repair in oil and gas fields, in particular to a hydraulically retractable high-strength fishing spear. Background Art

[0002] With the continuous increase in reserves and production in the offshore oil and gas industry and the rapid development of the deepwater industry, conventional slider spears or retractable spears are commonly used in current well repair and salvage operations. When the target is recovered or the fish is stuck, the slider spear cannot be safely withdrawn underground. Retractable spears are difficult to transmit and even more difficult to withdraw due to wellbore restrictions, deviated sections, horizontal section lengths, torque, tension, and bit pressure. This results in minor rework and serious overhauls, increasing the difficulty of operations. Utility Model Content

[0003] In order to solve the problem that conventional retractable fishing spears cannot be used normally in ultra-deep wells, horizontal wells and production wells without the ability to rotate the tubing string, the utility model provides a high-strength fishing spear, which can solve the above problem by hydraulic release and forward release, thereby greatly improving the reliability and safety of the fishing operation.

[0004] The utility model is realized by adopting the following technical solutions.

[0005] A high-strength salvage spear comprises an upper joint, on which a spring sleeve, slips, a piston extension cylinder, a piston and a guide cone are sequentially arranged; a spring is provided between the upper joint and the spring sleeve; a plurality of key slots uniformly distributed along the circumference are formed in the middle of the spear shaft of the upper joint, the slips are embedded in the key slots, and the key slots and the slips are engaged with each other via sloped steps; the two ends of the slips are respectively embedded in the spring sleeve and the piston extension cylinder, and the piston extension cylinder is connected to the piston via a thread; one end of the guide cone abuts against the piston, and the other end is threadedly connected to the upper joint; an adjusting screw is also embedded in the tail end of the guide cone.

[0006] Furthermore, a plurality of slope steps 1 are provided at the bottom of the keyway; a plurality of slope steps 2 are provided on the inner side of the slip, and the slope steps 1 and the slope steps 2 are meshed with each other.

[0007] Furthermore, the angles between the first slope step and the second slope step and the horizontal line are both 17°.

[0008] Furthermore, a longitudinal pressure-conducting hole is provided at the tail of the upper joint.

[0009] Furthermore, a boss 1 is formed on the inner wall of the spring sleeve, and the boss 1 is embedded in the key slot and slides along the key slot.

[0010] Furthermore, the outer wall of the slip is provided with a left-handed fishing thread.

[0011] Furthermore, a second boss is provided on the inner wall of the piston extension cylinder, and the second boss is embedded in the key groove and slides along the key groove.

[0012] Furthermore, a through hole is formed inside the adjusting screw, and the diameter of the through hole is smaller than the diameter of the through hole of the upper joint.

[0013] This application has the following beneficial effects.

[0014] (1) The salvage spear of the utility model has high strength: due to the ingenious design of the slip part, the salvage spear can exert a large tonnage of gripping force without slipping;

[0015] (2) The utility model can realize the release by forward rotation in emergency situations: since the slip is designed with a left-handed salvage thread on the outside, the release can be achieved by forward rotation of the pipe string;

[0016] (3) The utility model can realize hydraulic release in emergency situations: the hydraulic force pushes the slips to move along the slope in the keyway of the upper joint, thereby realizing the release function;

[0017] (4) The utility model has an undercut function: the slips and the upper joint lance are connected by a keyway, so torque can be transmitted to perform undercut operations. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural diagram of the utility model;

[0019] Figure 2 It is a structural diagram of the upper joint of the utility model;

[0020] Figure 3 This is a schematic diagram of the structure of the utility model slip Figure 1 ;

[0021] Figure 4 This is a schematic diagram of the structure of the utility model slip Figure 2 .

[0022] Among them, 1. Upper joint; 11. Spear rod; 12. Keyway; 13. Slope step 1; 14. Pressure guide hole; 2. Spring; 3. Spring sleeve; 31. Boss 1; 4. Slip; 41. Slope step 2; 42. Salvage thread; 5. Piston extension cylinder; 51. Boss 2; 6. Piston; 7. Guide cone; 8. Adjustment screw. DETAILED DESCRIPTION

[0023] The present patent application is further described below with reference to the embodiments.

[0024] like Figure 1-4 As shown, a high-strength salvage spear includes an upper joint 1, a spring 2, a spring sleeve 3, a slip 4, a piston extension tube 5, a piston 6, a guide cone 7, and an adjusting screw 8.

[0025] The upper connector 1 and spring sleeve 3 form a cavity for accommodating the spring 2. One end of the slip 4 rests on boss 1 31 within the spring sleeve 3, and the other end rests on boss 2 51 within the piston extension cylinder 5. The piston extension cylinder 5 is threadedly connected to the piston 6. The guide cone 7 is threadedly connected to the upper connector 1, with the other end of the guide cone 7 resting on the piston 6. The adjusting screw 8 is also threadedly connected to the guide cone 7. The spring 2 of this application is compressed during installation. Under the action of the spring force, the slip 4 slides along the sloped step 13 of the upper connector 1 to reach its maximum outer diameter.

[0026] Specifically, the upper joint 1 of the present application adopts an integrated structure, with a joint thread connected to the drill string at the upper end and a lower end connected to the guide cone 7. A through hole is provided in the center of the upper joint 1, and a keyway 12 is milled evenly in the middle of the lance 11 of the upper joint 1 for accommodating the slips 4. The bottom of the keyway 12 is designed with multiple sloped steps 13, preferably 5 sloped steps 13. A longitudinal pressure guide hole 14 is designed at the tail of the upper joint 1.

[0027] The spring housing 3 is hollow, with the spring 2 housed at one end and evenly spaced bosses 31 at the other. The placement and number of bosses 31 correspond to the key slots 12 on the lance 11. The bosses 31 are positioned within the key slots 12 and can slide back and forth along the direction of the key slots 12. To the right of the bosses 31 is a larger hole, into which one end of the slip 4 is inserted and rests against the bosses 31.

[0028] The slip 4 is an elongated strip designed to fit within the keyway 12 of the lance 11. It features a left-handed, zigzag fishing thread 42 on its exterior and multiple ramp steps 41 on its interior, which mesh with ramp steps 13 within the keyway 12. Specifically, both ramp steps 13 and 41 are angled at 17° with the horizontal. This allows for longitudinal movement when the slip 4 and the upper connector 1 undergo lateral relative movement. The left-handed fishing thread 42 on the slip 4 allows for release by rotating the pipe string forward.

[0029] The piston extension tube 5 is hollow and features evenly distributed second bosses 51. The placement and number of these bosses 51 correspond to the key slots 12 on the lance 11. These bosses 51 are positioned within the key slots 12 and can slide back and forth along the direction of the key slots 12. The end of the slip 4, distal from the spring sleeve 3, is positioned within the piston extension tube 5 and rests against the second bosses 51 within the piston extension tube 5. The other end of the piston extension tube 5 is threaded for connection to the piston 6.

[0030] One end of the guide cone 7 is matched with the piston 6, and the interior is connected to the tail of the upper joint 1 through an internal thread. The other end of the guide cone 7 is designed with an internal thread, and the adjusting screw 8 is screwed into the threaded hole. The adjusting screw 8 of the present application is a hexagon socket screw with a through hole inside. The diameter of the through hole is smaller than the diameter of the through hole of the upper joint 1.

[0031] The utility model upper joint 1, piston 6 and guide cone 7 together form a hydraulic system. Parts such as piston 6, piston extension cylinder 5, slips 4 and spring sleeve 3 can move left and right under the action of hydraulic force and spring 2 elastic force.

[0032] The utility model is connected to the lowermost end of the fishing string. When the tool and the slip reach the fish cavity, the slip 4 automatically retracts under the action of the hanging weight, so that the slip completely enters the fish cavity, and the spring 2 is compressed. When the pipe string is lifted, the spring 2 pushes the slip 4 outward, forcing the slip teeth to bite into the inner wall of the fallen object. At the same time, due to the action of multiple slope steps 13 in the keyway 12 in the middle of the upper connector 1, the slip 4 also expands outward, thereby grasping the fallen fish. The slip and the tool core shaft are connected by a keyway, so torque can be transmitted for reverse operation. When the fallen fish is stuck and cannot be lifted out, the following two methods can be used for disengagement according to actual needs on site: A: Mechanical disengagement: By rotating the pipe string to the right, the tool is turned out of the fish cavity; B: Hydraulic disengagement: Under the action of hydraulic force, the piston 6 pushes the slip 4 back, and the tool can be lifted out of the fish cavity.

[0033] The specific operation method of the utility model is as follows:

[0034] 1. Check on the ground whether the slip size (actual measurement) is appropriate, whether the spring is tightened, and apply engine oil to the slips and slip grooves.

[0035] 2. Lower the drill string to the top of the fish, remember the hanging weight and square of the drill string, start the pump to wash the well and rinse the fish head.

[0036] 3. Lower the drill string, introduce it into the fish cavity, check whether the fish is entering the cavity and whether the fish is entering the cavity, as well as the changes in the suspended weight.

[0037] 4. Slowly lift the drill string. When the suspended weight increases, the fish has been caught.

[0038] 5. When performing the inverted operation, lift the hanging weight to the designed inverted load, and then increase it by 10 to 20 kN before performing the inverted operation.

[0039] When the fish is stuck and cannot be lifted out, the following two methods can be used to disengage it according to the actual needs on site:

[0040] (1) Add 5-10kN lifting force to the original hanging weight, then rotate the string forward to remove the tool from the fish cavity;

[0041] (2) Lower the tubing string and start pumping to flush the well (displacement is controlled at 15m3 / h). Under the action of hydraulic force, the piston pushes the slips to retract, and the pipe string is slowly lifted to lift the tool out of the fish cavity.

[0042] The embodiments of this specific implementation method are all preferred embodiments of the present utility model, and are not intended to limit the scope of protection of the present utility model. Therefore, any equivalent changes made based on the structure, shape, and principle of the present utility model should be included in the scope of protection of the present utility model.

Claims

1. A high-strength salvage spear, characterized by: The invention comprises an upper joint (1), on which a spring sleeve (3), a slip sleeve (4), a piston extension cylinder (5), a piston (6) and a guide cone (7) are sequentially arranged; a spring (2) is arranged between the upper joint (1) and the spring sleeve (3); a plurality of key slots (12) uniformly distributed along the circumference are formed in the middle of the lance (11) of the upper joint (1), the slip sleeve (4) is embedded in the key slots (12), and the key slots (12) and the slip sleeve (4) are engaged with each other through a slope step; the two ends of the slip sleeve (4) are respectively embedded in the spring sleeve (3) and the piston extension cylinder (5), and the piston extension cylinder (5) is connected to the piston (6) through a thread; one end of the guide cone (7) abuts against the piston (6), and the other end is threadedly connected to the upper joint (1); and an adjusting screw (8) is also embedded in the tail end of the guide cone (7).

2. A high-strength salvage spear according to claim 1, characterized in that: The bottom of the keyway (12) is provided with a plurality of slope steps 1 (13); the inner side of the slip (4) is provided with a plurality of slope steps 2 (41), and the slope steps 1 (13) and the slope steps 2 (41) are meshed with each other.

3. The high-strength salvage spear according to claim 2, characterized in that: The angles between the first slope step (13) and the second slope step (41) and the horizontal line are both 17 degrees.

4. The high-strength salvage spear according to claim 1, characterized in that: A longitudinal pressure-guiding hole (14) is provided at the tail of the upper joint (1).

5. The high-strength salvage spear according to claim 1, characterized in that: A boss (31) is formed on the inner wall of the spring sleeve (3), and the boss (31) is embedded in the key slot (12) and slides along the key slot (12).

6. The high-strength salvage spear according to claim 1, characterized in that: The outer wall of the slip (4) is provided with a left-handed fishing thread (42).

7. The high-strength salvage spear according to claim 1, characterized in that: A second boss (51) is provided on the inner wall of the piston extension cylinder (5), and the second boss (51) is embedded in the key groove (12) and slides along the key groove (12).

8. The high-strength salvage spear according to claim 1, characterized in that: A through hole is formed inside the adjusting screw (8), and the diameter of the through hole is smaller than the diameter of the through hole of the upper joint (1).

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