Special female tap for fishing screw drill

Abstract

The utility model relates to the technical field of screw salvage, in particular to a special female tap for salvage of a screw drill, which comprises a special female tap, a straight buckle and a conical buckle, the straight buckle and the conical buckle are arranged inside the special female tap, the straight buckle is communicated with the inside of the conical buckle, the straight buckle is communicated with the outer side of the special female tap, and the conical buckle is communicated with the outer side of the special female tap. A connecting opening is formed in the peripheral side of the end, away from the straight buckle, of the inner wall of the special female taper and connected with an outer drill rod, and at least three drainage grooves are formed in the inner wall of the taper buckle. Under the combined use of the straight buckle and the conical buckle, the special female tap can be in double-layer connection positioning with a salvaged screw rod, the effect of double-layer connection positioning of the special female tap and the screw rod is achieved, the situation of falling in the salvage process is prevented, the double functions of simultaneous salvage and circulation can be achieved, the success probability of unfreezing salvage is greatly improved, and the salvage efficiency is improved. A large amount of manpower, material resources and financial resources can be saved through one-time fishing success, and major assets are protected against loss.

Description

Technical Field

[0001] This utility model relates to the field of screw retrieval technology, specifically a special female cone for retrieval screw drill tools. Background Technology

[0002] Although screw drill bit technology is very mature, it can still occasionally break and fall into the well. Conventional retrieval cones cannot simultaneously achieve retrieval and drilling fluid circulation when the drive shaft assembly falls into the well due to stuck drill bit. Therefore, circulation and unsticking measures cannot be implemented. In this case, it is necessary to go down the drill bit multiple times to disassemble the drive shaft assembly into multiple parts and retrieve each part one by one.

[0003] Stuck drill bit prevents simultaneous retrieval and drilling fluid circulation when the drive shaft assembly is lowered into the well. Multiple drilling operations are required to retrieve each component of the drive shaft assembly one by one, wasting a significant amount of manpower, material resources, financial resources, and drilling time.

[0004] Therefore, a special mother cone for retrieval screw drill tools is proposed to solve the problems mentioned above. Utility Model Content

[0005] To address the shortcomings of existing technologies, this utility model provides a special female cone for retrieving screw drill bits. Its unique structure enables dual functions of retrieval and drilling fluid circulation. A unique retrieval tool structure is designed specifically for the special structure of the screw drill bit drive shaft assembly. This dual function allows for simultaneous vibration of the moving drill bit, circulation of sand, and acid soaking to release stuck parts, significantly increasing the probability of successful unsticking. There is even a chance of successful unsticking and retrieval in a single attempt.

[0006] To achieve the above objectives, this utility model provides the following technical solution: it includes a dedicated female cone, and a straight buckle and a conical buckle disposed inside the dedicated female cone, wherein the straight buckle is internally connected to the conical buckle and the straight buckle is externally connected to the dedicated female cone;

[0007] The inner wall of the special female cone is provided with a connection port on the periphery of the end away from the straight buckle, and the connection port is connected to the outer drill rod;

[0008] The inner wall of the cone buckle has at least three drainage grooves.

[0009] Preferably, the straight buckle has a uniform overall structure, and the inner wall of the straight buckle is provided with threads for buckling.

[0010] Preferably, the cone buckle has an overall cone-shaped structure, and the inner wall of the cone buckle is provided with threads for buckling.

[0011] Preferably, the tapered buckle is at its maximum point near the connection port, and the diameter of the maximum point of the tapered buckle is smaller than the diameter of the straight buckle.

[0012] Preferably, the three drainage grooves are evenly distributed on the inner periphery of the straight buckle, and the drainage grooves are inclined at the same angle as the conical buckle.

[0013] Preferably, the connection port has a tapered structure, and the inner wall of the connection port is provided with NC threads.

[0014] Compared with the prior art, this utility model provides a special female cone for retrieving screw drill bits, which has the following beneficial effects:

[0015] 1. By using a combination of straight and conical buckles, it can achieve a double connection and positioning with the screw being retrieved, forming a double-layer connection and positioning effect between the dedicated female cone and the screw, preventing it from falling off during the retrieval process.

[0016] 2. Compared with the existing technology, the special salvage tool of this application can realize the dual functions of simultaneous salvage and circulation, which greatly improves the probability of successful card unlocking and salvage. A successful salvage in one go can save a lot of manpower, material resources and financial resources, and protect important assets from loss.

[0017] 3. By setting the tapered buckle to a tapered shape, the movement space of the screw gradually decreases as it moves inside the tapered buckle, resulting in a stronger tightening effect as the movement distance increases. This further improves the strength of the screw connection during retrieval. Combined with the tapped thread on the inner wall of the tapered buckle, it ensures the tightness of the connection between the special female cone and the screw. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the cross-sectional structure of the special mother cone of this utility model;

[0019] Figure 2 This is a schematic diagram of the overall structure of the special female cone of this utility model;

[0020] Figure 3 This is a schematic diagram of the vertical cross-section structure of the special mother cone of this utility model;

[0021] Figure 4 This is a schematic diagram of the utility model in use.

[0022] In the diagram: 1. Straight thread; 2. Conical thread; 3. Connecting port; 4. Drainage groove; 5. Special female cone. Detailed Implementation

[0023] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0024] Example:

[0025] Please see Figure 1 - Figure 4 In this embodiment, a special female cone for retrieval screw drill includes a special female cone 5, and a straight buckle 1 and a conical buckle 2 disposed inside the special female cone 5. The straight buckle 1 and the conical buckle 2 are internally connected, and the straight buckle 1 is connected to the outside of the special female cone 5.

[0026] A connection port 3 is provided on the circumference of the inner wall of the special female cone 5 away from the straight thread 1, and the connection port 3 is connected to the outer drill rod.

[0027] The inner wall of the cone buckle 2 has at least three drainage grooves 4;

[0028] Among them, the overall external structure of the special female cone 5 is the same as that of the existing female cone, and its internal straight buckle 1, cone buckle 2 and connecting port 3 are in a connected state.

[0029] By using the combination of straight buckle 1 and conical buckle 2, it can be double-connected and positioned with the screw being retrieved, forming a double-layer connection and positioning effect between the special female cone 5 and the screw, preventing it from falling off during the retrieval process;

[0030] Furthermore, by combining straight buckle 1 and conical buckle 2, the positioning depth of the screw is increased, thereby increasing the contact area of ​​the screw positioning and preventing the screw from becoming loose and falling off due to insufficient contact area, thus improving the salvage efficiency.

[0031] With the connection of the drainage channel 4, the drilling fluid on the outside can flow through the drainage channel 4 into the cone buckle 2, the straight buckle 1 and the screw, so as to achieve the effect of synchronous operation of fishing and drilling fluid circulation.

[0032] The straight buckle 1 has a uniform structure, and the inner wall of the straight buckle 1 is provided with threads for buckling.

[0033] The cone buckle 2 has an overall cone-shaped structure, and the inner wall of the cone buckle 2 is provided with threads for buckling;

[0034] The cone buckle 2 has its maximum cone shape at the end closest to the connection port 3, and the diameter of the maximum cone shape is smaller than the diameter of the straight buckle 1.

[0035] Three drainage channels 4 are evenly distributed on the inner wall periphery of the straight buckle 1, and the drainage channels 4 and the conical buckle 2 have the same inclination.

[0036] The connection port 3 has a tapered structure, and the inner wall of the connection port 3 is provided with NC50 threads;

[0037] By setting the straight thread 1 to a uniform structure, the smooth and stable movement of the screw through the inside of the straight thread 1 can be ensured, and the screw surface can be tapped under the support of the threaded thread inside the straight thread 1.

[0038] By setting the tapered buckle 2 to a tapered shape, the movement space of the screw gradually decreases as it moves inside the tapered buckle 2, resulting in a stronger tightening effect as the movement distance increases. This further improves the strength of the screw connection during retrieval. Combined with the tapped thread on the inner wall of the tapered buckle 2, it ensures the tightness of the connection between the special female cone 5 and the screw.

[0039] The specific operation process is as follows:

[0040] The first step is to connect connector 3 to the drill pipe and begin drilling. The second step is to drill down until the top of the fish head (straight thread 1) contacts the top of the drive shaft assembly. The third step is to rotate the special female cone 5, causing straight thread 1 to begin forming threads on the screw, and the special female cone 5 gradually moves downwards. The fourth step is to wait until the special female cone 5 has moved downwards to a certain point, at which point the cone thread 2 begins to contact the drive shaft assembly, and the threading process begins. The fifth step is to stop moving downwards when the special female cone 5 stops, indicating that the threading is complete. The sixth step is to turn on the drilling fluid to begin circulation, thus completing the fishing and drilling fluid circulation process. Figure 4 The middle arrow points to the flow path and direction of the drilling fluid.

[0041] The installation, connection, or setting methods disclosed in this embodiment are all common mechanical connection methods. As long as they can achieve their beneficial effects, they can be implemented. Therefore, this embodiment will not elaborate on their specific structural composition and working principle.

[0042] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A special female cone for retrieval screw drill bits, characterized in that: It includes a dedicated female cone (5), and a straight buckle (1) and a conical buckle (2) disposed inside the dedicated female cone (5). The straight buckle (1) is internally connected to the conical buckle (2), and the straight buckle (1) is externally connected to the dedicated female cone (5). The inner wall of the special female cone (5) is provided with a connection port (3) on the periphery of the end away from the straight buckle (1), and the connection port (3) is connected to the outer drill rod; The inner wall of the cone buckle (2) is provided with at least three drainage grooves (4).

2. The special female cone for retrieval screw drill bit according to claim 1, characterized in that: The straight buckle (1) has a uniform structure, and the inner wall of the straight buckle (1) is provided with threads for buckling.

3. The special female cone for retrieval screw drill bit according to claim 1, characterized in that: The cone buckle (2) has an overall cone-shaped structure, and the inner wall of the cone buckle (2) is provided with threads for buckling.

4. The special female cone for retrieval screw drill bit according to claim 2, characterized in that: The tapered buckle (2) is at its maximum point near the connection port (3), and the diameter of the maximum point of the tapered buckle is smaller than the diameter of the straight buckle (1).

5. The special female cone for retrieval screw drill bit according to claim 1, characterized in that: The three drainage grooves (4) are evenly distributed on the inner wall periphery of the straight buckle (1), and the drainage grooves (4) and the conical buckle (2) have the same inclination.

6. The special female cone for retrieval screw drill bit according to claim 1, characterized in that: The connection port (3) has a tapered structure, and the inner wall of the connection port (3) is provided with NC50 threads.

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