Hydraulic fishing spear sealing assembly and using method thereof

Abstract

The lower end of an upper connector is connected with a body, the body is sleeved with a sealing component and a sealing push ring, the upper end of the sealing push ring is embedded into an opening in the end of the sealing component, an outer rack is fixed to the inner hole wall of the sealing push ring, a gear is arranged at an installation opening of the body, and the gear is meshed with the outer rack. A center rod is installed in an inner hole of the body, an inner hole of the center rod is of a blind hole structure with the upper end closed, a communication opening communicated with the inner hole is formed in the periphery of the upper end of the center rod, the periphery of the hollow rod is movably sleeved with a back cap, a rack piston and a reset spring in sequence from top to bottom, and the rack piston is meshed with the gear. A gear and rack structure is adopted, it is guaranteed that a sealing component is in an original state and is smaller than the inner diameter of a fish when the fishing spear sealing assembly is put into the fish or lifted upwards to fish the fish, and when sealing is needed, a pump is started to press the sealing component under the action of liquid pressure and the rack and gear structure to open the sealing component, and sealing and outer circulation are established. The sealing stability is enhanced, and the fishing success rate is increased.

Description

TECHNICAL FIELD

[0001] The present application relates to a hydraulic spear sealing assembly and its use method, belonging to the technical field of oil and gas field exploitation fishing equipment. BACKGROUND

[0002] The oil and gas fishing operation is a very complex process, and generally uses a spear to carry out fishing operation. The simple use of the spear to fish the fish cannot form a seal, and once the fish annulus is blocked by the stuck debris, the mud circulation cannot be used to flush the fish annulus. In the prior art, the conventional fishing operation is to fix a rubber sleeve at the outer circle of the shaft of the lower end of the spear to form an inner seal of the fish to establish an external circulation. The size of the rubber sleeve is larger than the inner hole of the fish, and the seal is formed by extrusion. However, the downhole environment is complex, and such structure causes the spear to be not easy to enter the fish, and the rubber ring is easy to be damaged before entering the inner hole of the fish, resulting in seal failure. SUMMARY

[0003] The purpose of the present application is to provide a hydraulic spear sealing assembly and its use method. When used with the spear to fish the fish, the outer annulus can form a stable high-pressure mud circulation during the fishing operation of the fish.

[0004] The technical scheme of the present application is a hydraulic spear sealing assembly, comprising an upper joint, a body connected to the lower end of the upper joint, a sealing component and a sealing push ring successively sleeved on the outer periphery of the body from top to bottom, the sealing component being a downward opening structure, the upper end of the sealing push ring being embedded into the opening at the end of the sealing component, the upper end surface of the sealing component abutting against the lower end surface of the upper joint, an external gear rack being fixed on the inner hole wall of the sealing push ring, an installation port being provided on the body, a gear being provided at the installation port, the gear being engaged with the external gear rack, a center rod being loaded in the large hole of the upper segment of the inner hole of the body, the inner hole of the center rod being a blind hole structure with a closed upper end, a communication port being provided on the outer periphery of the center rod and being in communication with the inner hole, a back cap, a gear rack piston and a return spring successively movably sleeved on the outer periphery of the hollow rod from top to bottom, the gear rack piston abutting against the back cap and the return spring at both ends, the return spring being in a compressed state and the gear rack piston covering the communication port under normal circumstances, the gear rack piston being engaged with the gear.

[0005] In the foregoing hydraulic spear sealing assembly, the sealing component comprises a metal piece with a U-shaped structure and a rubber piece with an open lower end, the upper end of the rubber piece being sleeved into the metal piece, and the upper end surface of the metal piece abutting against the lower end surface of the upper joint.

[0006] In the foregoing hydraulic spear sealing assembly, the lower end of the rubber piece is a horn mechanism with an outward opening, and the upper end of the sealing push ring is a conical structure.

[0007] The lower end of the sealing push ring is provided with an axial groove, and the convex ribs on the outer periphery of the upper end of the body are clamped into the axial groove.

[0008] The lower end of the center rod is provided with a step, and the back cap is threadedly connected to the outer periphery of the upper end of the center rod.

[0009] The middle part of the rack piston is a rack structure, and the two ends are smooth surface structures.

[0010] The inner hole wall of the sealing push ring is fixed with a plurality of outer racks, and the body is arrayed with a plurality of mounting ports, and each mounting port is provided with a gear.

[0011] A use method of the hydraulic fishing spear sealing assembly, the sealing push ring is opened outwardly by the gear, the outer rack and the rack piston moving in the axial direction of the hollow rod, so that the sealing part is reliably sealed with the pipe column, and the sealing push ring returns under the action of the reset spring to make the sealing part retract and unseal when the sealing operation is completed and the pressure is released.

[0012] In the use method of the hydraulic fishing spear sealing assembly, the medium with pressure is injected into the water eye of the hydraulic fishing spear sealing assembly, the rack piston moves downward under the action of the pressure and extrudes the reset spring, and the communication port is exposed to form a passage, the rack piston drives the gear to rotate during the movement, so that the outer rack and the sealing push ring move upward, and the sealing push ring extends into the sealing part.

[0013] The sealing assembly of the present application adopts a gear and rack structure, which ensures that the sealing part of the fishing spear sealing assembly is in the original state and smaller than the inner diameter of the fish when the fishing spear and the sealing assembly are placed in the fish or when the fishing spear is lifted to fish the fish, and the sealing part is opened by the liquid pressure and the gear and rack structure when sealing is needed, so that the sealing and external circulation are established.

[0014] When the fishing spear and the sealing assembly are placed in the fish or when the foreign matter stuck in the outer annulus is washed away by the circulating mud, the pump is closed and pressurized, at this time, the rack piston is pushed upward by the reset spring, the sealing push ring moves downward, and the rubber part of the sealing part is closed to stop working, so that the service life of the sealing assembly is increased, and the fishing spear is more easily put into the inner hole of the fish when the fishing spear is used to fish the fish.

[0015] The sealing part rubber piece is expanded outwardly to press and seal the inner hole of the fish, the inner flow channel of the water eye is opened, the mud is circulated outwardly to flush the jammed sundries in the fish outer annular space, the expansion force of the sealing part is increased with the pressure in a certain range, the leakage is avoided, the stability of the sealing is enhanced, and the success rate of fishing is improved. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 Fig. 1 is a structural schematic diagram of the present application when the pump is not opened and pressurized;

[0017] Figure 2 Fig. 2 is a structural schematic diagram of the present application when the pump is opened and pressurized;

[0018] Figure 3 Fig. 3 is a structural schematic diagram of the present application when the present application is used with the fish spear;

[0019] Figure 4 Fig. 4 is a three-dimensional structural schematic diagram of the present application;

[0020] Figure 5 Fig. 5 is a three-dimensional structural schematic diagram of the central rod;

[0021] Figure 6 Fig. 6 is an installation structural schematic diagram of the gear.

[0022] The figure marks are as follows: 1 is an upper joint, 2 is a body, 3 is a sealing part, 4 is a sealing push ring, 5 is an outer rack, 6 is a gear, 7 is a central rod, 8 is a communication port, 9 is a rack piston, 10 is a reset spring, 11 is a metal piece, 12 is a rubber piece, 13 is an axial groove, 14 is a convex rib, and 15 is a back cap. DETAILED DESCRIPTION

[0023] The present application is further described below in combination with the drawings and examples, but is not as the basis for limiting the present application.

[0024] The embodiment of the present application discloses a hydraulic spear sealing assembly, which comprises an upper joint 1, a body 2 is threadedly connected to the lower end of the upper joint 1, a sealing part 3 and a sealing push ring 4 are sequentially sleeved on the outer periphery of the body 2 from top to bottom, the sealing part 3 is of a downward opening structure, the upper end of the sealing push ring 4 is embedded into the opening at the end of the sealing part 3, the upper end surface of the sealing part 3 abuts against the lower end surface of the upper joint 1, an external gear rack 5 is fixed on the inner hole wall of the sealing push ring 4, an installation port is arranged on the body 2, a gear 6 is arranged at the installation port, the gear 6 is engaged with the external gear rack 5, a central rod 7 is arranged in the large hole of the upper section of the inner hole of the body 2, the inner hole of the central rod 7 is a blind hole structure with a closed upper end, a plurality of communication openings 8 are arranged on the outer periphery of the upper end of the central rod 7 and are communicated with the inner hole, a hollow rod 7 is sequentially movably sleeved with a back cap 15, a gear rack piston 9 and a reset spring 10 from top to bottom on the outer periphery of the central rod 7, the gear rack piston 9 abuts against the back cap 9 and the reset spring 10 at two ends respectively, under normal circumstances, the reset spring 10 is in a compressed state, and the gear rack piston 9 covers the communication openings 8, and the gear rack piston 9 is engaged with the gear 6.

[0025] The sealing part 3 comprises a metal piece 11 with a U-shaped structure and a rubber piece 12 with an open lower end, the upper end of the rubber piece 12 is sleeved into the metal piece 11, the upper end surface of the metal piece 11 abuts against the lower end surface of the upper joint 1, and the sealing part 3 is limited and fixed through the structure, so that the sealing part 3 cannot slide upward after being extruded by the sealing push ring 4.

[0026] The lower end of the rubber piece 12 is a horn mechanism opening outward, and the upper end of the sealing push ring 4 is a conical structure, so that the rubber piece 12 can be well expanded when the sealing push ring 4 moves upward, and sealing is realized.

[0027] The lower end of the sealing push ring 4 is provided with an axial groove 13, and a convex rib 14 on the outer periphery of the upper end of the body 2 is clamped into the axial groove 13, so that the sealing push ring 4 and the body 2 cannot rotate relative to each other, and the external gear rack 5 in the inner hole of the sealing push ring 4 and the gear 6 are always in engagement.

[0028] The lower end of the central rod 7 is provided with a step, one end of the reset spring 10 abuts against the step, and the back cap 15 is threadedly connected to the outer periphery of the upper end of the central rod 7. During installation, the reset spring 10 and the gear rack piston 9 are sleeved on the outer periphery of the central rod 7, and then the back cap 15 is screwed, so that the reset spring 10 and the gear rack piston 9 are limited and fixed, and installation and disassembly are convenient.

[0029] The middle part of the gear rack piston 9 is a gear rack structure, and the two ends are smooth surface structures. The gear rack part is used for cooperating with the gear 6, and the smooth surface structures at the two ends form a seal between the inner hole wall of the body 2.

[0030] A plurality of outer toothed racks 5 are arranged and fixed on the inner hole wall of the sealing push ring 4, and a plurality of mounting ports are arrayed on the body 2, and each mounting port is provided with a gear 6, and the stability of the whole structure is ensured by the plurality of gears 6 and the plurality of outer toothed racks 5.

[0031] The hydraulic spear sealing assembly mainly comprises an upper joint 1, a body 2, a sealing component 3, a sealing push ring 4, a toothed rack piston 9, a reset spring 10, a center rod 7, a back cap 15, a gear 6 and the like.

[0032] Specific parts cooperation and functions are as follows:

[0033] The upper joint 1:

[0034] 1. The upper inner hole is provided with a connecting thread matched with a drilling tool, and is used for connecting the drilling tool;

[0035] 2. The lower part is threadedly connected with the body 2, forms a seal and transmits torque, and can also compress the sealing component 3, so that the sealing component 3 is fixed with the body 2 and forms a sealing surface.

[0036] The sealing component 3:

[0037] 1. The upper part is a metal piece 11, and the lower part is a rubber piece 12, which is extruded to open the inner hole of the rubber piece 12 to form a seal;

[0038] 2. The lower part of the rubber piece 12 is in contact with the sealing push ring 4, and the contact surface is a tapered surface, when the sealing push ring 4 moves upward, it will extrude the sealing component 3 outward, so that the rubber piece 12 opens outward;

[0039] 3. When working, the sealing component 3 is located in the fish falling inner hole, and when the rubber piece 12 is extruded to open outward, the sealing component 3 can form a seal with the fish falling inner hole.

[0040] The sealing push ring 4:

[0041] 1. The upper tapered surface of the sealing push ring 4 is in contact with the sealing component 3, and the cooperation and effect have been described above;

[0042] 2. The inner hole of the sealing push ring 4 is gap-fitted with the body 2, and can slide axially on the body 2;

[0043] 3. The inner hole of the sealing push ring 4 is fixed with the outer toothed rack 5, the outer toothed rack 5 is engaged with the gear 6, and when the gear 6 rotates, it can drive the sealing push ring 4 to slide on the body 2;

[0044] 4. An axial groove 13 is formed in the lower end surface of the sealing push ring 4, which cooperates with the protruding rib 14 of the body 2 to ensure that the sealing push ring 4 cannot rotate relative to the body 2, so that the outer toothed rack 5 in the inner hole of the sealing push ring 4 is always in meshing state with the gear 6.

[0045] Gear 6:

[0046] 1. Gear 6 is sleeved on the gear shaft. During installation, the gear 6 is placed at the installation port of the body 2, the gear shaft is inserted from the insertion hole on one side of the installation port, and after passing through the gear 6, it is inserted into the insertion hole on the other side. The threaded plug with the gear shaft is placed at the insertion hole on both sides, so as to realize the fixed installation of the gear 6.

[0047] 2. The bottom end of the gear 6 is engaged with the rack piston 9, and the top end is engaged with the external rack 5.

[0048] Center rod 7:

[0049] 1. The center rod 7 is in interference fit with the body 2, and is relatively fixed and sealed;

[0050] 2. The center rod 7 is in clearance fit with the inner hole of the rack piston 9, and the rack piston 9 can slide axially and be sealed in the center rod 7;

[0051] 3. The center rod 7 has a communication port 8 in the upper part, and when the rack piston 9 slides through the position of the communication port 8, the channel is opened, and the liquid can flow from the upper inner hole of the body 2 to the lower inner hole of the body through the inner hole of the center rod 7.

[0052] Back cap 15:

[0053] 1. The back cap 15 is threadedly connected with the upper end of the center rod 7, and blocks the lower end rack piston 9, so as to avoid the rack piston 9 from sliding out.

[0054] Rack piston 9:

[0055] 1. The inner hole of the rack piston 9 is in clearance fit with the center rod 7, and the rack piston 9 can slide axially and be sealed in the center rod 7;

[0056] 2. The outer circle of the rack piston 9 is in clearance fit with the body 2, and the rack piston 9 can slide axially and be sealed in the inner hole of the body 2;

[0057] 3. The lower end of the rack piston 9 has a reset spring 10, and the reset spring 10 is always in a compressed state;

[0058] 4. When the upper part of the tool is pressurized, the rack piston 9 is compressed, and when the pressure is greater than the elastic force and friction force of the reset spring 10, the rack piston 9 will move downward, and when it moves to the position where the communication port 8 of the center rod 7 is opened, the channel is opened, and the fluid can flow downward.

[0059] The principle of the hydraulic spear sealing assembly of the application is that the gear 6, the external rack 5 and the rack piston 9 move in the axial direction of the hollow rod 7 to drive the sealing push ring 4 to open the sealing part 3 outward to form reliable sealing with the pipe string. When the sealing operation is completed and the pressure is released, the sealing push ring 4 is moved back under the action of the reset spring 10 to make the sealing part 3 retract to release the sealing, so as to facilitate the tool to be taken out.

[0060] During use, by injecting pressure medium into the water eye of the hydraulic spear sealing assembly, the rack piston 9 moves downward under the action of pressure and extrudes the return spring 10, and the communication port 8 is exposed to form a passage. The rack piston 9 drives the gear 5 to rotate during the movement, thereby driving the external rack 5 and the sealing push ring 4 to move upward, so that the sealing push ring 4 extends into the sealing component 3.

[0061] The hydraulic spear sealing assembly of the present application is in the original state when the pump is not started, at this time, the rack piston 9 is in the upper limit position under the thrust of the return spring 10, the sealing push ring 4 is in the lower limit position, the rubber part 12 of the sealing component 3 is closed, the diameter is smaller than the inner diameter of the fish, and the sealing component 3 is in the original state and does not form a seal with the inner wall of the fish. After the pump is started and pressurized, it is in a sealed state, the spear and the hydraulic spear sealing assembly are lowered to the inner hole of the fish, and the spear slips engage the inner hole of the fish. At this time, the hydraulic spear sealing assembly is also in the inner hole of the fish, the pump is pressurized, at this time, the rack piston 9 moves downward under the action of pressure, the gear 6 rotates to drive the sealing push ring 4 to move upward, thereby extruding the rubber part 12 of the sealing component 3 to expand outward and form a seal with the inner hole of the fish. At this time, the passage at the communication port 8 of the center rod 7 is open, the mud can pass through the water eye to the lower part, and the sealing component 3 is always in a sealed state. The mud flows to the annulus outside the fish to flush the stuck debris in the annulus, so that the flushed stuck debris returns upward, reducing the force of the stuck fish. After the stuck debris in the annulus is flushed away, the fish can be pulled out by lifting the spear under the action of the spear and the fish. At this time, the pump is stopped, the pressure on the upper part of the rack piston 9 is reduced, and the return spring 10 drives the rack piston 9 to move upward. At this time, the sealing push ring 4 is driven to move downward, the rubber part 12 of the sealing component 3 is retracted, and the hydraulic spear sealing assembly and the inner hole of the fish are not sealed.

Claims

1. A hydraulic spear seal assembly, characterized by: The utility model provides a sealing assembly of hydraulic grab hook, including upper joint (1), the lower end of upper joint (1) is connected with body (2), and the outer periphery of body (2) is from top to bottom with sealing component (3) and sealing push ring (4) sleeve joint, sealing component (3) is to the downward opening structure, and the upper end of sealing push ring (4) is embedded to sealing component (3) end opening, and the upper end surface of sealing component (3) is against the lower end surface of upper joint (1), and the inner hole wall of sealing push ring (4) is fixed with external gear rack (5), and the upper body (2) is provided with installation mouth, and the installation mouth is provided with gear (6), and gear (6) is engaged with external gear rack (5), and the upper segment big hole of body (2) inner hole is loaded with center rod (7), and the inner hole of center rod (7) is the blind hole structure of upper end closure, and the upper end outer periphery of center rod (7) is equipped with the communication port (8) of communication with inner hole, and hollow rod (7) outer periphery is from top to bottom in proper order with back cap (15), rack piston (9) and reset spring (10) movable sleeve joint, and rack piston (9) both ends are respectively against back cap (9) and reset spring (10), and rack piston (9) is engaged with gear (6), and under normal circumstances, rack piston (9) will cover communication port (8).

2. A hydraulic spear seal assembly as defined in claim 1, wherein: The sealing component (3) includes a U-shaped metal piece (11) and a rubber piece (12) with an open lower end, the upper end of the rubber piece (12) is sleeved into the metal piece (11), and the upper end surface of the metal piece (11) is against the lower end surface of the upper joint (1).

3. A hydraulic spear seal assembly as defined in claim 2, wherein: The lower end of the rubber piece (12) is a horn mechanism opening outward, and the upper end of the sealing push ring (4) is a conical structure.

4. A hydraulic spear seal assembly as defined in claim 1, wherein: The lower end of the sealing push ring (4) is provided with an axial groove (13), and the protruding rib (14) on the outer periphery of the upper end of the body (2) is clamped into the axial groove (13).

5. A hydraulic spear seal assembly as defined in claim 1, wherein: The lower end of the center rod (7) is provided with a step, one end of the reset spring (10) is against the step, and the back cap (15) is threadedly connected to the outer periphery of the upper end of the center rod (7).

6. A hydraulic spear seal assembly as defined in claim 1, wherein: The middle part of the rack piston (9) is a rack structure, and the two ends are smooth surface structures.

7. A hydraulic spear seal assembly as defined in claim 1, wherein: A plurality of external gear racks (5) are fixed on the inner hole wall of the sealing push ring (4), and a plurality of installation mouths are arrayed on the body (2), and one gear (6) is arranged at each installation mouth.

8. A method of using a hydraulic spear seal assembly as claimed in any one of claims 1-7, characterized by: When the sealing operation is completed, the sealing push ring (4) moves back under the action of the reset spring (10) to make the sealing component (3) retract and release the seal.

9. The method of using a hydraulic spear seal assembly of claim 8, wherein: By injecting the medium with pressure into the water eye of the hydraulic grab hook sealing assembly, the rack piston (9) moves downward and presses the reset spring (10) under the action of the pressure, and the communication port (8) is exposed to form a passage, the rack piston (9) drives the gear (5) to rotate during the movement, thereby driving the external gear rack (5) and the sealing push ring (4) to move upward, and the sealing push ring (4) extends into the sealing component (3).

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