Multi-stage female tap

Abstract

The utility model discloses a multistage female tap which comprises an upper female tap and a lower female tap which are connected through screw threads, spiral screw threads used for making threads for the outer wall of a falling object are arranged in the upper female tap and the lower female tap, and the aperture of an internal through hole from one end, far away from the upper female tap, of the lower female tap to one end, far away from the lower female tap, of the lower female tap is gradually reduced; the end, away from the upper female cone, of the lower female cone is connected with a shark mouth guiding shoe, arc-shaped openings are formed in the upper side and the lower side of the end, away from the lower female cone, of the shark mouth guiding shoe respectively, and the vertex of the upper arc-shaped opening is farther than the vertex of the lower arc-shaped opening than the lower female cone. The problem that in the prior art, due to the fact that a falling object body is fragile, an object cannot be grabbed, and fishing efficiency is low is solved.

Description

Technical Field

[0001] The utility model belongs to the technical field of fishing for dropped objects in oilfield pipes, and particularly relates to a multi-stage female taper Background Art

[0002] A female taper is a commonly used fishing tool for dropped objects in pipes. It is specifically used to make threads on the outer wall of pipe-shaped objects such as tubing and drill pipes, and can be used to fish for rod-shaped dropped objects without an inner hole or with a blocked inner hole. However, when the existing female taper is used to fish for corroded tubing or dropped objects in pipes with relatively weak body strength, due to the relatively fragile body of the dropped object, during the process of making threads and fishing, there are situations where the object cannot be grasped firmly and the fishing is not solid, and the phenomenon of thread detachment often occurs, resulting in low fishing efficiency. Summary of the Utility Model

[0003] The purpose of the utility model is to provide a multi-stage female taper, which solves the problem of low fishing efficiency caused by the relatively fragile body of the dropped object in the prior art, resulting in the inability to grasp the object firmly.

[0004] The technical solution adopted by the utility model is that the multi-stage female taper includes an upper female taper and a lower female taper connected by threads. The upper female taper and the lower female taper are internally provided with spiral threads for making threads on the outer wall of the dropped object, and the inner through-hole diameter from the end of the lower female taper far from the upper female taper to the end of the upper female taper far from the lower female taper gradually decreases; a shark nose guide shoe is connected to the end of the lower female taper far from the upper female taper. Arc-shaped openings are respectively formed on the upper and lower sides of the end of the shark nose guide shoe far from the lower female taper, and the vertex of the upper arc-shaped opening is farther from the lower female taper than the vertex of the lower arc-shaped opening.

[0005] The features of the utility model further lie in that

[0006] The upper female taper includes an upper female taper upper sub, the inner wall of the upper female taper upper sub is provided with threads for connecting with a drill pipe, the other end of the upper female taper upper sub is connected with an upper female taper barrel, and the spiral threads for making threads on the outer wall of the dropped object are formed on the inner wall of the upper female taper barrel. The end of the upper female taper barrel far from the upper female taper upper sub is connected with an upper female taper lower sub, and the upper female taper lower sub is connected with the lower female taper.

[0007] The inner through-diameter of the upper female taper barrel gradually decreases from the end close to the upper female taper lower sub to the other end, and the taper ratio of the through-diameter of the upper female taper barrel is 1:20.

[0008] The lower female taper includes a lower female taper upper sub, one end of the lower female taper upper sub is threadedly connected with the upper female taper lower sub, the other end is connected with a lower female taper barrel, and the spiral threads for making threads on the outer wall of the dropped object are arranged on the inner wall of the lower female taper barrel. The end of the lower female taper barrel far from the lower female taper upper sub is connected with a lower female taper lower sub, and the lower female taper lower sub is threadedly connected with the shark nose guide shoe.

[0009] The inner diameter of the lower female taper cylinder decreases from one end near the lower sub of the lower female taper to the other end, and the taper ratio of the inner diameter of the lower female taper cylinder is 1:20.

[0010] The inner wall of the upper sub of the lower female taper is lined with milling materials.

[0011] The rotation directions of the spiral threads in the upper female taper cylinder and the lower female taper cylinder are unified as left-handed or right-handed.

[0012] The beneficial effects of the present utility model are as follows:

[0013] (1) The multi-stage female taper of the present utility model includes an upper female taper and a lower female taper. The inner diameter of the upper female taper is smaller, and the inner diameter of the lower female taper is larger. The function of the lower female taper is to initially shape the corroded oil pipe by rotating to make a thread, removing the rust and scale on the surface of the corroded fish head. The function of the upper female taper is to capture the stronger part of the corroded fish head by rotating to make a thread, avoiding accidental unthreading due to inability to grasp or fish firmly, resulting in the failure of fishing.

[0014] At the same time, the effective space of the inner cavity of the guide shoe is greatly increased by the upper and lower asymmetrically opened shark nose guide shoes, which is used to guide the severely deformed fish head into the inner cavity of the female taper.

[0015] (2) By lining the inner wall of the upper sub of the lower female taper with milling materials in the multi-stage female taper of the present utility model, the rust on the outer surface of the corroded fish head can be cleaned during rotation, making it easier for the spiral threads inside the upper female taper cylinder to make a thread on the outer wall of the dropped object, improving the success rate of fishing. Description of the Drawings

[0016] Figure 1 is a schematic structural diagram of the multi-stage female taper of the present utility model;

[0017] Figure 2 is the structure of the shark nose guide shoe in the multi-stage female taper of the present utility model;

[0018] Figure 3 is a schematic structural diagram of the upper female taper in the multi-stage female taper of the present utility model;

[0019] Figure 4 is a schematic structural diagram of the lower female taper in the multi-stage female taper of the present utility model.

[0020] In the figure, 1. upper female taper, 1-1. upper sub of the upper female taper, 1-2. upper female taper cylinder, 1-3. lower sub of the upper female taper, 2. lower female taper, 2-1. upper sub of the lower female taper, 2-2. lower female taper cylinder, 2-3. lower sub of the lower female taper, 3. shark nose guide shoe. Detailed Implementation Manner

[0021] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.

[0022] Embodiment 1

[0023] The multi-stage female taper of the present utility model, as Figure 1 shown, includes an upper female taper 1. One end of the upper female taper 1 is connected to a drill pipe, and the other end is connected to a lower female taper 2. One end of the lower female taper 2 away from the upper female taper 1 is connected to a shark nose guide shoe 3 for guiding the fish top into the inner cavity of the female taper.

[0024] Furthermore, as Figure 2 shown, on the upper and lower sides of one end of the shark nose guide shoe 3 away from the lower female taper 2, arc-shaped openings are respectively formed. The upper and lower arc-shaped openings are asymmetric. The vertex of the upper arc-shaped opening is farther from the lower female taper than the vertex of the lower arc-shaped opening, thus forming a shark nose-like structure, greatly increasing the effective space of the inner cavity of the guide shoe for guiding a severely deformed fish top into the inner cavity of the female taper.

[0025] Embodiment 2

[0026] The multi-stage female taper of the present utility model includes an upper female taper 1. One end of the upper female taper 1 is connected to a drill pipe, and the other end is connected to a lower female taper 2. One end of the lower female taper 2 away from the upper female taper 1 is connected to a shark nose guide shoe 3 for guiding the fish top into the inner cavity of the female taper.

[0027] Furthermore, as Figure 3 shown, the upper female taper 1 includes an upper female taper upper sub 1-1. The inner wall of the upper female taper upper sub 1-1 is provided with threads for connecting to the drill pipe. The other end of the upper female taper upper sub 1-1 is connected to an upper female taper cylinder 1-2. The inner wall of the upper female taper cylinder 1-2 is provided with spiral threads for threading the outer wall of the dropped object. The internal through diameter of the upper female taper cylinder 1-2 gradually decreases from the end close to the lower female taper 2 to the end of the upper female taper upper sub 1-1, and the taper ratio of the through diameter of the upper female taper cylinder 1-2 is 1:20. In view of the special properties of the corroded fish top, the taper ratio inside the upper female taper cylinder 1-2 is designed to be 1:20, thereby increasing the threading length of the inner wall of the upper female taper cylinder 1-2 and improving the fishing success rate. One end of the upper female taper cylinder 1-2 away from the upper female taper upper sub 1-1 is connected to an upper female taper lower sub 1-3, and the upper female taper lower sub 1-3 is connected to the lower female taper 2.

[0028] Embodiment 3

[0029] The multi-stage female taper of the utility model includes an upper female taper 1. One end of the upper female taper 1 is connected to a drill pipe, and the other end is connected to a lower female taper 2. One end of the lower female taper 2 away from the upper female taper 1 is connected to a shark nose guide shoe 3 for guiding the fish top into the inner cavity of the female taper.

[0030] Further, as Figure 4 shown, the lower female taper 2 includes an upper joint 2-1 of the lower female taper. One end of the upper joint 2-1 of the lower female taper is threadedly connected to the lower joint 1-3 of the upper female taper, and the other end is connected to a barrel 2-2 of the lower female taper. A spiral thread is provided on the inner wall of the barrel 2-2 of the lower female taper for threading the outer wall of the dropped object. The inner diameter of the barrel 2-2 of the lower female taper gradually decreases from the end close to the shark nose guide shoe 3 to the end of the upper female taper 1, and the slope ratio of the inner diameter of the barrel 2-2 of the lower female taper is the same as that of the inner slope of the barrel 1-2 of the upper female taper. In this embodiment, the slope ratio of the inner diameter of the barrel 2-2 of the lower female taper is 1:20. The threading length on the inner wall of the barrel 2-2 of the lower female taper is increased to improve the fishing success rate. One end of the barrel 2-2 of the lower female taper away from the upper joint 2-1 of the lower female taper is connected to a lower joint 2-3 of the lower female taper, and the lower joint 2-3 of the lower female taper is threadedly connected to the shark nose guide shoe 3.

[0031] Further, the diameter at the minimum inner diameter of the barrel 2-2 of the lower female taper is larger than the diameter at the maximum inner diameter of the barrel 1-2 of the upper female taper.

[0032] Embodiment 4

[0033] Based on Embodiment 3, a milling material is laid on the inner wall of the upper joint 2-1 of the lower female taper for cleaning the rust on the outer surface of the corroded fish top during rotation, so that the spiral thread inside the barrel 1-2 of the upper female taper can more easily thread the outer wall of the dropped object, and the barrel 1-2 of the upper female taper can be fastened to the dropped object through thread engagement, improving the fishing success rate.

[0034] Further, the rotation directions of the spiral threads in the upper female taper 1 and the lower female taper 2 are unified as left-handed or right-handed, that is, the rotation directions of the spiral threads in the barrel 1-2 of the upper female taper and the barrel 2-2 of the lower female taper are unified as left-handed or right-handed.

[0035] When the multi-stage female taper of the utility model is in use, it is specifically implemented according to the following steps:

[0036] Step 1: Connect all threaded connection parts between the upper female taper 1 and the lower female taper 2 firmly. Threadedly connect the upper joint 1-1 of the upper female taper to the fishing string, and threadedly connect the lower joint 2-3 of the lower female taper to the shark nose guide shoe 3.

[0037] Step 2: Lower the female taper to the position of the fish top, apply appropriate drilling pressure, and select to rotate the string left-handedly or right-handedly on the ground according to the left-handed or right-handed rotation of the fishing string to achieve the purpose of the fishing string.

[0038] Step 3: After threading is completed, lift out the fishing string.

Claims

1. Multi-stage female taper, characterized in that, It includes an upper female taper (1) and a lower female taper (2) connected by screw threads. The upper female taper (1) and the lower female taper (2) are internally provided with spiral threads for threading the outer wall of the dropped object, and the aperture of the internal through-hole from the end of the lower female taper (2) far from the upper female taper (1) to the end of the upper female taper (1) far from the lower female taper (2) becomes smaller from large. One end of the lower female taper (2) far from the upper female taper (1) is connected with a shark nose guide shoe (3). Circular arc openings are respectively arranged on the upper and lower sides of one end of the shark nose guide shoe (3) far from the lower female taper (2). The vertex of the upper circular arc opening is farther from the lower female taper (2) than the vertex of the lower circular arc opening.

2. The multi-stage female tap according to claim 1, wherein, The upper female taper (1) includes an upper female taper upper sub (1-1). Threads for connecting with the drill pipe are arranged on the inner wall of the upper female taper upper sub (1-1). The other end of the upper female taper upper sub (1-1) is connected with an upper female taper cylinder (1-2). The spiral threads for threading the outer wall of the dropped object are arranged on the inner wall of the upper female taper cylinder (1-2). One end of the upper female taper cylinder (1-2) far from the upper female taper upper sub (1-1) is connected with an upper female taper lower sub (1-3), and the upper female taper lower sub (1-3) is connected with the lower female taper (2).

3. The multi-stage female tap according to claim 2, wherein The internal diameter of the upper female taper cylinder (1-2) becomes smaller from large from the end close to the upper female taper lower sub (1-3) to the other end, and the diameter slope ratio of the upper female taper cylinder (1-2) is 1:

20.

4. The multi-stage female tap according to claim 2 or 3, characterized in that, The lower female taper (2) includes a lower female taper upper sub (2-1). One end of the lower female taper upper sub (2-1) is threadedly connected with the upper female taper lower sub (1-3), and the other end is connected with a lower female taper cylinder (2-2). The spiral threads for threading the outer wall of the dropped object are arranged on the inner wall of the lower female taper cylinder (2-2). One end of the lower female taper cylinder (2-2) far from the lower female taper upper sub (2-1) is connected with a lower female taper lower sub (2-3), and the lower female taper lower sub (2-3) is threadedly connected with the shark nose guide shoe (3).

5. The multi-stage female tap according to claim 4, wherein, The internal diameter of the lower female taper cylinder (2-2) becomes smaller from large from the end close to the lower female taper lower sub (2-3) to the other end, and the diameter slope ratio of the lower female taper cylinder (2-2) is 1:

20.

6. The multi-stage female tap according to claim 4, wherein, The inner wall of the lower female taper upper sub (2-1) is paved with milling materials.

7. The multi-stage female taper according to claim 4, wherein The rotation directions of the spiral threads in the upper female taper cylinder (1-2) and the lower female taper cylinder (2-2) are unified as left-handed or right-handed.

Images