Plunger fishing tool

Abstract

A plunger salvage tool comprises two salvage claws, an expansion sleeve, a sleeve, a center rod, a first stress application rod, a second stress application rod and a locking block, the two salvage claws are two symmetrical elastic metal claws, protruding clamping claws are arranged on the inner walls of the front ends of the salvage claws, and the clamping claws are used for catching and fixing the neck of a salvage plunger when in a contraction state; the locking block is installed in the lock pin hole, and when the center rod is screwed out, the locking block can be driven to pull the fishing claw to slide on the expansion sleeve; the expansion sleeve is a hollow shaft sleeve, a sleeve is arranged on the expansion sleeve in a sleeving mode, internal threads are arranged to be connected with threads at the end of the rear half section of the expansion sleeve, a center rod is arranged in the expansion sleeve, the rear end of the sleeve is coaxially connected with the corresponding position of the center rod through coarse threads, and a first stress application rod is arranged on the sleeve and is perpendicular to and fixed to the wall of the sleeve. When the first stress application rod is used for fixing the sleeve, the center rod is screwed in or out of the sleeve by rotating the center rod.

Description

Technical Field

[0001] The utility model relates to an oil well construction tool and device, in particular to a plunger fishing tool. Background Art

[0002] The plunger gas lift technology is an economical and effective method for oil production by drainage. Plunger gas lift is an artificial lift method for oil wells. Its basic principle is to use a freely moving plunger to move up and down in the tubing to lift the oil out of the well. The gas lift energy comes from the gas in the tubing-casing annulus, and the most commonly used gas lift gas is the produced associated gas. The working principle of plunger gas lift is to lift the oil well through the up and down movement of the plunger. The plunger moves up and down in the tubing to lift the oil out of the well. When the plunger falls by its own weight, the valve at the bottom opens to allow oil to enter the tubing. When the plunger collides with the buffer at the bottom of the well, the valve closes. The gas in the well or the injected gas makes the plunger move upward to lift the oil. Plunger gas lift is applicable to high gas-oil ratio wells with weak natural flowing capacity or low production.

[0003] Putting a plunger into the gas well borehole and using the gas production volume of the gas well to push the plunger to run periodically in the tubing. The plunger forms a mechanical sealing interface between the lifted gas and liquid, which can effectively prevent the gas from flowing upward and the liquid from falling back, reduce the "slippage" effect of the liquid, and increase the liquid drainage efficiency of the gas well.

[0004] In the application of the plunger gas lift technology, to ensure its effectiveness and safety, the plunger needs to be taken out for inspection and replacement regularly. However, there is currently a problem that the tubing diameter of a large number of construction wells does not match the plunger blowout preventer pipe of the gas production tree, which makes it impossible to use a conventional manual plunger catcher to capture and put the running plunger; only rely on the plunger sleeve to capture and use a special fishing tool to fish and recover and put the plunger. However, when fishing and recovering and putting the plunger, there is a risk of the plunger falling. Once it hits the valve plate of the gas production tree valve, it may cause damage to the plunger and the valve, thus affecting the operation of the plunger and the normal production of the gas well.

[0005] To solve the above problems, we have developed a new type of plunger fishing tool. This tool can not only effectively complete the tasks of fishing and recovering and putting the plunger, but also avoid the risk of the plunger falling, ensuring the normal operation and production safety of the gas well.

[0006] The prior art uses a strong magnetic fishing rod to adsorb the plunger through its large magnetic properties, so as to realize the operations of fishing and recovering and putting the plunger.

[0007] During the process of using a strong magnetic fishing rod to fish and retrieve and place the plunger, due to unstable operation or scraping during the hoisting and lowering process, there is a risk of the plunger falling; moreover, during the production operation process of the plunger, foreign objects are likely to adhere to its surface, which further affects the adsorption performance of the strong magnetic fishing rod, thereby increasing the possibility of the plunger falling. Once the plunger falls and hits the valve plate of the gas production tree valve, it may also cause damage to the plunger and the valve. Summary of the Invention

[0008] The technical problem to be solved by the present invention is to address the deficiencies of the above tools and develop a plunger fishing tool.

[0009] The technical solution of the present invention is a plunger fishing tool, which is characterized by including two fishing claws, an expansion sleeve, a sleeve, a center rod, a first and a second force - increasing rod, and a locking block. The two fishing claws are two symmetric elastic metal claws. The inner wall of the front end of the fishing claw is provided with a protruding clamping claw (90 - degree shoulder) for capturing and fixing the fishing neck of the retrieved plunger when in the contracted state.

[0010] The front half of the fishing claw is a claw rod and a claw, and the rear half of the fishing claw is a semi - cylindrical arc - shaped groove. A locking pin hole is opened on the surface of the rear half of the fishing claw. After the provided locking block is installed in the locking pin hole, when the center rod is screwed out, it can drive the locking block and then pull the fishing claw to slide on the expansion sleeve; the expansion sleeve is a hollow bushing, the diameter of the front end is larger than that of the rear end and the wall thickness is the same. Two grooves are opened on the column wall of the front half of the expansion sleeve for embedding the front half of the two fishing claws. The rear half of the expansion sleeve is wrapped by the semi - cylindrical arc - shaped groove of the rear half of the fishing claw and is wrapped to the journal part of the expansion sleeve; two symmetric locking block slideways are opened on the rear half of the expansion sleeve, and the end of the rear half of the expansion sleeve is provided with an external thread; a sleeve is sleeved on the expansion sleeve and is provided with an internal thread for connecting with the thread at the end of the rear half of the expansion sleeve. The center rod is inside the expansion sleeve, and the rear end of the sleeve and the corresponding position of the center rod are coaxially connected by a coarse - thread screw. A first force - increasing rod is provided on the sleeve, and the first force - increasing rod is perpendicular and fixed to the sleeve wall. When using the first force - increasing rod to fix the sleeve, the center rod is screwed into or out of the sleeve by rotating the center rod; the center rod is provided with two steps. The first step contacts the locking block for driving the locking block and then driving the fishing claw to move upward (backward) along the groove of the expansion sleeve, so that the fishing claw gradually opens. When the second step contacts the expansion sleeve housing, the center rod is stopped; a spring is sleeved on the claw rod and the claw. When the center rod is screwed in, the fishing claw moves forward (forward) along the groove of the expansion sleeve, and the spring tightens the fishing claw.

[0011] The locking block is a convex structure, the upper convex part is inserted into the locking pin hole of the fishing claw and at the same time inserted into the locking block slideway on the expansion sleeve and contacts the outer edge of the center rod; the bottom surface of the convex shape is an arc structure, the radian is the same as the outer diameter of the center rod body and adheres to the center rod body, and the bottom surface of the locking block slides freely on the surface of the center rod; the upper convex part of the locking block moves freely in the locking block slideway of the expansion sleeve.

[0012] When the center rod is rotated out, the center rod drives the locking block and then pulls the fishing claw to move upward along the expansion sleeve groove to put it in an expanded state; when the center rod is rotated in, under the action of the spring force, the fishing claw moves downward along the expansion sleeve groove, and the fishing claw is slowly released until it reaches the predetermined groove position of the expansion sleeve, putting it in a retracted state.

[0013] The expansion sleeve is provided with two symmetrical grooves corresponding to the two salvage claws respectively. When the salvage claws are sleeved in the expansion sleeve and embedded in the grooves, the salvage claws are in a contracted state; when the salvage claws are pulled upward, the salvage claws gradually expand along the grooves and are in an expanded state.

[0014] When the spring and the center rod are screwed in, the fishing claws can move downward along the expansion sleeve groove under the action of the spring force.

[0015] Each fishing claw has two 45-degree steps and one 30-degree step on its surface. These steps mate with the step surfaces of the expansion sleeve groove, allowing the fishing claw to precisely retract and expand along the position of the expansion sleeve groove. The center rod is sheathed in the expansion sleeve, and the rear half of the center rod has external threads that mate with the internal threads of the sleeve. The first and second force rods are fixed to the sleeve and the center rod respectively. When the center rod is unscrewed, it drives the locking block, which in turn drives the fishing claw to move upward along the expansion sleeve groove, causing it to expand. After assembly, the locking block can move along the locking block slide on the expansion sleeve.

[0016] Beneficial effects: The salvage tool is modular in design and simple in structure. It can be quickly assembled and disassembled on site, and its parts can be replaced.

[0017] (1) Through the rotation of the center rod, the locking block and the fishing claw are linked together, so that the relative position between the fishing claw and the expansion sleeve can be quickly adjusted.

[0018] (2) The unique design structure allows the fishing claw to be quickly and flexibly contracted and expanded by adjusting the relative position of the fishing claw and the expansion sleeve, thereby accurately executing the salvage and deployment tasks of the plunger.

[0019] (3) This equipment is specially designed for plunger gas lift wellheads. Compared with traditional methods, its fishing claws show more stable performance when clawing out the plunger, effectively avoiding the accidental fall of the plunger.

[0020] (4) The tool is easy to operate, saves operation time, can quickly switch between salvage and delivery modes, and can adapt to various complex working environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1A This is a schematic diagram of the salvage claw structure;

[0022] Figure 1BSchematic diagram of the structure when the two fishing claws are combined; the combined joint is the locking pin hole 2;

[0023] Figure 2A Schematic diagram of the expansion sleeve structure (cross-sectional view);

[0024] Figure 2B Schematic diagram of the expansion sleeve structure (outer shape view);

[0025] Figure 3 Schematic diagram when the fishing claw is sleeved on the expansion sleeve and at the groove position;

[0026] Figure 4 Schematic diagram of the sleeve structure;

[0027] Schematic diagram of the central rod structure of Figure 5;

[0028] Figure 6 Schematic diagram of the locking block structure;

[0029] Figure 7 Schematic diagram of the spring structure;

[0030] Figure 8 Schematic diagram of the tool assembly (in the retracted state of the fishing claw).

[0031] Figure 9 Schematic diagram of the tool assembly (in the expanded state of the fishing claw).

[0032] Figure 10 Schematic diagram when the fishing tool is fishing (clamped).

[0033] Figure 11 Schematic diagram when the fishing tool is fishing (released). Detailed implementation method

[0034] As shown in the figure, the fishing claw 1 has two symmetric locking pin holes 2. After the locking block is installed in the locking pin hole, when the central rod is screwed out, it can drive the locking block and then pull the fishing claw.

[0035] Two symmetric fishing claws are designed. There is a 90-degree shoulder (i.e., a right-angled step) inside the fishing claw. When the fishing claw is in the retracted state, it is used to capture and fix the fishing neck of the fishing plunger. The front

[0036] The surface of a single fishing claw is designed with two 45-degree shoulders and one 30-degree shoulder. These shoulders fit with the shoulder surfaces of the expansion sleeve grooves, enabling the fishing claw to perform precise contraction and expansion operations along the position of the expansion sleeve grooves.

[0037] The expansion sleeve 3 is a hollow sleeve. The diameter of the front end is larger than that of the rear end. There is a groove 4 at the front end; and an external thread 3-1 at the rear end;

[0038] The central rod is sleeved inside the expansion sleeve. The rear half section of the central rod is provided with an external thread 6, which mates with the internal thread of the sleeve. The first and second force - applying rods are respectively fixed to the sleeve and the central rod. When the central rod is screwed out backward, it drives the locking block, and then drives the fishing claws to move upward along the grooves of the expansion sleeve, making them in an open state. After assembly, the locking block can move on the locking - block slideway on the expansion sleeve;

[0039] Each fishing claw surface is provided with two 45 - degree stepped shoulders and one 30 - degree stepped shoulder. These stepped shoulders fit with the stepped surfaces of the grooves of the expansion sleeve, enabling the fishing claws to perform precise contraction and opening operations along the positions of the grooves of the expansion sleeve.

[0040] When the central rod is screwed out, the central rod drives the locking block and then pulls the fishing claws to move upward along the grooves of the expansion sleeve, making them in an expanded state. When the central rod is screwed in, under the action of the spring force, the fishing claws move downward along the grooves of the expansion sleeve, and the fishing claws slowly release until the fishing claws reach the predetermined groove position of the expansion sleeve, making them in a contracted state.

[0041] The front end of the expansion sleeve 3 is provided with two symmetrical grooves 4 corresponding to the protrusions of the claw catches of the two fishing claws. When the fishing claws are sleeved inside the expansion sleeve and are in the embedded groove positions, the fishing claws are in a contracted state. When the fishing claws are pulled upward, the fishing claws gradually expand along the groove positions, and the fishing claws are in an expanded state.

[0042] There are two symmetrical locking - block slideways 5 opened on the expansion sleeve. After the tool is assembled, the locking block can move on the locking - block slideway on the expansion sleeve. See Figure 2A 、 Figure 2B 、 Figure 3 Schematic diagram of the fishing claws sleeved on the expansion sleeve and in the groove positions.

[0043] The sleeve 7 is connected to the expansion sleeve through an internal thread 8. The sleeve and the central rod are coaxially connected by a coarse - thread screw. The sleeve is provided with a first force - applying rod 9, and the first force - applying rod is perpendicular and fixed to the sleeve wall. When using the first force - applying rod to fix the sleeve, the rotation of the central rod can achieve the screwing in or out of the central rod inside the sleeve. See Figure 4 Schematic diagram of the sleeve structure.

[0044] The central rod is divided into two parts. The front end 10 - 3 and the rear end 10 - 4 of the central rod are connected by an anchoring method. The rear end of the central rod is provided with a second force - applying rod 9 - 1 that is perpendicular and fixed to the central rod. The rotation of the central rod realizes the screwing in or out of the central rod inside the sleeve. The front end of the central rod is screwed into the sleeve through a threaded sleeve;

[0045] After the fishing tool is assembled, when the fishing claws are in the contracted state, as the central rod is screwed out a certain distance, the first shoulder surface 10-1 at the front end of the central rod contacts the locking block. Continuing to screw out the rear end of the central rod, the front end of the central rod drives the locking block through the thread and the step, and then drives the fishing claws to move upward along the groove of the expansion sleeve, causing the fishing claws to gradually expand. When the second shoulder surface 10-2 of the central rod contacts the expansion sleeve housing, the central rod cannot be screwed out further. At this time, the fishing claws are fully expanded, and this is the release state of the fishing tool.

[0046] When the fishing claws are in the contracted state, as the central rod is screwed in, under the action of the spring force, the fishing claws move downward along the groove of the expansion sleeve, and the fishing claws are slowly released until the fishing claws reach the predetermined groove position of the expansion sleeve and are in the contracted state.

[0047] Other accessories, the locking block 11, the locking block is a convex structure. When installed, the upper convex part is inserted into the locking pin hole of the fishing claw. The bottom surface of the convex part is an arc structure, and the radian is consistent with the outer diameter of the central rod body. When the central rod is screwed in and out, the locking block can slide freely on the surface of the central rod; at the same time, the locking block can move freely in the locking block slideway of the expansion sleeve when the central rod is screwed in and out.

[0048] Function: When the central rod is screwed out, it drives the locking block and then drives the fishing claws to move upward along the groove of the expansion sleeve to make them in the expanded state. When the central rod is screwed in, under the action of the spring force of the spring 12, the fishing claws can move downward along the groove of the expansion sleeve.

[0049] Working principle Figure 8 、 Figure 9 、 Figure 10 、 Figure 11 :

[0050] (1) Plunger delivery

[0051] As Figure 9 The schematic diagram of the fishing tool carrying the plunger shown, the fishing tool carries the plunger. After lowering it to the position of the plunger sleeve and seating it, fix the force-applying rod on the fixed sleeve. By rotating the force-applying rod of the central rod, the central rod is slowly screwed out. As the central rod is screwed out a certain distance, the first shoulder surface 10-1 of the central rod contacts the locking block. Continuing to screw out the central rod, the central rod drives the locking block and then drives the fishing claws to move upward along the groove of the expansion sleeve, causing the fishing claws to gradually expand. When the second shoulder surface 10-2 of the central rod contacts the expansion sleeve housing, the central rod cannot be screwed out further. At this time, the fishing claws are fully expanded, and at this time the plunger 13 is released. Lift the fishing tool, and the delivery of the plunger is completed.

[0052] (2) Plunger fishing

[0053] The fishing tool is in the release state. Lower the fishing tool to the plunger fishing neck. As Figure 10As shown in the figure, the force-applying rod on the fixed central rod rotates the force-applying rod on the rotating sleeve, causing the sleeve to move downward. Under the action of the spring force, the fishing claws move downward along the grooves of the expansion sleeve, and the fishing claws slowly release until they reach the predetermined groove position of the expansion sleeve, making them in a contracted state. At this time, lifting the fishing tool will lift the plunger out of the plunger sleeve, thus completing the fishing of the plunger.

[0054] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those of ordinary skill in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of the present invention without departing from the principles and purposes of the present invention.

Claims

1. A plunger fishing tool, characterized in that, It includes two fishing claws, an expansion sleeve, a sleeve, a center rod, a first and a second force - increasing rod, and a locking block. The two fishing claws are two symmetrical elastic metal claws. The inner wall of the front end of the fishing claw is provided with a protruding clamping claw, which is used to capture and fix the neck of the fishing plunger in the contracted state. The front half of the fishing claw is a claw rod and a claw, and the rear half of the fishing claw is a semi - cylindrical arc groove. A lock pin hole is opened on the surface of the rear half of the fishing claw. The provided locking block is installed in the lock pin hole. When the center rod is screwed out, it can drive the locking block and then pull the fishing claw to slide on the expansion sleeve. The expansion sleeve is a hollow shaft sleeve. The diameter of the front end is larger than that of the rear end and the wall thickness is the same. Two grooves are opened on the column wall of the front half of the expansion sleeve for embedding the front half of the two fishing claws. The rear half of the expansion sleeve is wrapped by the semi - cylindrical arc groove of the rear half of the fishing claw and is wrapped to the journal part of the expansion sleeve. Two symmetrical locking - block slideways are opened on the rear half of the expansion sleeve, and the end of the rear half of the expansion sleeve is an external thread. A sleeve is sleeved on the expansion sleeve and is provided with an internal thread to connect with the thread at the end of the rear half of the expansion sleeve. The center rod is inside the expansion sleeve. The rear end of the sleeve is coaxially connected with the corresponding position of the center rod by a coarse - thread screw. A first force - increasing rod is provided on the sleeve. The first force - increasing rod is perpendicular and fixed to the sleeve wall. When using the first force - increasing rod to fix the sleeve, screwing the center rod in or out in the sleeve is achieved by rotating the center rod. A spring is sleeved on the claw rod and the claw. When the center rod is screwed in, the fishing claw moves forward along the groove of the expansion sleeve, and the spring makes the fishing claw tighten. The center rod is provided with two steps. The first step contacts the locking block, which is used to drive the locking block and then drive the fishing claw to move backward along the groove of the expansion sleeve, making the fishing claw gradually open. When the second step contacts the expansion - sleeve housing, the center rod is stopped. The locking block is a convex structure. The upper convex part is inserted into the lock pin hole of the fishing claw and at the same time inserted into the locking - block slideway on the expansion sleeve and contacts the outer edge of the center rod. The bottom surface of the convex shape is an arc structure, and the radian is the same as the outer diameter of the center - rod body and adheres to the center - rod body. The bottom surface of the locking block slides freely on the surface of the center rod. The upper convex part of the locking block moves freely in the locking - block slideway of the expansion sleeve.

2. The plunger fishing tool according to claim 1, characterized in that, Each fishing claw surface is provided with two 45 - degree steps and a 30 - degree step, and these steps fit with the step surfaces of the expansion - sleeve groove.

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