A double hollow rod central pipe leak detection device

Abstract

The utility model discloses a kind of center pipe leak detection devices of double hollow rod, and double hollow rod center pipe is connected, it includes: center pipe joint, device main body and conical sealing top rod, the device main body upper end is connected with the lower end of the center pipe joint and inside composition is by the passage from inlet to outlet, the double hollow rod center pipe is connected with the center pipe joint, and the double hollow rod center pipe lower end interface is connected with the passage inlet intercommunication;Conical sealing top rod is contained in the fixed groove of the device main body and reciprocating sliding under the action of elastic member, the top of the conical sealing top rod and the top of fixed groove are abutted and matched, it opens the passage when sliding to the bottom of fixed groove, and when sliding to the top of fixed groove, seal passage.The utility model solves the problem of judging whether double hollow sucker rod center pipe leaks.

Description

Technical Field

[0001] This utility model relates to the field of hot water circulation heating maintenance of double hollow rods for oil wells in oilfields, and in particular to a leak detection device for the central tube of a double hollow rod. Background Technology

[0002] Currently, during the extraction of high-pour-point oil wells, wax easily forms in the well tubing, causing sucker rod lag, well sticking, and other problems that affect normal well production. Hot water circulation with double hollow sucker rods is a good solution for viscosity reduction in the field. Softened hot water is pumped through the central tube of the double hollow rods using a circulation pump and returns from the annular space between the sucker rod and the central tube. The temperature melts the wax and high-pour-point oil deposits on the tubing and sucker rods, reducing the viscosity of the crude oil, lowering the well load, and ensuring normal well production. However, during the circulation process, sucker rod damage and hot water leakage are prone to occur. If there is a leak in the upper part of the central tube, the hot water will not circulate to the lower part and return to the wellhead, posing a risk of rod breakage in the double hollow rods. Double hollow sucker rod well operations are very costly, and a single operation can result in significant losses for the company. Determining whether the central tube of the double hollow sucker rod is leaking is a major challenge in the field, as there is no mature technology available. Summary of the Invention

[0003] The purpose of this invention is to provide a leak detection device for the central tube of a double hollow rod, which solves the problem of determining whether the central tube of a double hollow rod is leaking.

[0004] To achieve the purpose of this utility model, a double hollow rod center tube leak detection device is provided, connected to a double hollow rod center tube. It includes: a center tube connector, a device body, and a conical sealing top rod. The upper end of the device body is connected to the lower end of the center tube connector, and an internal channel from inlet to outlet is formed. The double hollow rod center tube is connected to the center tube connector, and the lower end interface of the double hollow rod center tube is connected to the inlet of the channel. The conical sealing top rod is housed in a fixed groove of the device body and slides back and forth under the action of an elastic element. The top of the conical sealing top rod abuts against the top of the fixed groove. When it slides to the bottom of the fixed groove, it opens the channel, and when it slides to the top of the fixed groove, it seals the channel.

[0005] Furthermore, the central tube connector is a hollow cylinder, and a sealing ring is provided inside the upper part of the central tube connector for sealing the central tube sealing groove of the connection.

[0006] Furthermore, the central pipe joint has three Y-shaped external pipe threads.

[0007] Furthermore, the main body of the device is a hollow cylinder with threads on the top.

[0008] Furthermore, the conical sealing top rod includes: a conical rod head at the top and a cylindrical slide at the bottom, with a rod body between the rod head and the slide body, and an elastic element sleeved on the rod body.

[0009] Furthermore, the tapered sealing top rod is made of corrosion-resistant downhole-specific carbon steel.

[0010] Furthermore, the elastic element is a spring.

[0011] Furthermore, the spring is a corrosion-resistant spring.

[0012] This invention offers the following advantages: The double hollow rod center tube leak detection device, in conjunction with the center tube of the double hollow sucker rod, establishes a unidirectional fluid flow control channel within the double hollow sucker rod. This channel allows for circulation during normal production and can also be automatically closed when the fluid flow reverses. By controlling the channel closure and combining it with wellhead data, it is possible to clearly determine whether there is a leak in the center tube of the double hollow rod. Leak detection can be performed on the center tube at any time during production and rod lowering operations. This efficiently identifies fault points in double hollow rod production wells, enabling timely and effective measures to prevent major accidents and reduce losses to the company. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of the double hollow rod center tube leak detection device of this utility model; Figure 2 This is a schematic diagram of the structure of the central tube connector of this utility model; Figure 3 This is a schematic diagram of the main body of the device of this utility model; Figure 4 This is a schematic diagram of the structure of the spring of this utility model. Detailed Implementation

[0014] 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.

[0015] Please see Figures 1-4This utility model provides a leak detection device for the central tube of a double hollow rod, which is connected to the central tube of the double hollow rod. It includes: a central tube connector 1, a device body 2 and a conical sealing top rod 3. The upper end of the device body 2 is connected to the lower end of the central tube connector 1 and forms a channel 8 from the inlet 81 to the outlet 82 inside. The external part of the central tube connector 1 is provided with three Y-shaped external tube threads 6 for connecting and fixing to the central tube of the sucker rod.

[0016] The main body 2 of the device is a hollow cylinder with a threaded top. A double hollow rod center tube is connected to a center tube connector 1, and the lower end of the double hollow rod center tube is connected to the inlet 81 of the channel 8. A conical sealing top rod 3 is housed in the fixing groove 21 of the main body 2 and slides back and forth under the action of an elastic element, which in this embodiment is a spring 4. The conical sealing top rod 3 includes: a conical rod head 31 at the top, a cylindrical slide block 32 at the bottom, and a rod body 33 between the rod head 31 and the slide block 31. A spring 4 is fitted onto the conical sealing rod body 3. The top of the conical sealing top rod 3 abuts against the top 22 of the fixing groove 21. When it slides towards the bottom of the fixing groove 21, it opens the channel 8, and when it slides towards the top of the fixing groove 21, it seals the channel 8. Further optimization is achieved by using corrosion-resistant downhole-specific carbon steel as the material for the conical seal 3.

[0017] The central tube connector 1 is a hollow cylinder. The upper part of the central tube connector 1 is equipped with a sealing ring for sealing the central tube sealing groove 5. The sealing ring can be an O-ring.

[0018] The working process of this utility model's double hollow rod center tube leak detection device is as follows: The leak detection device is connected during the tubing string operation and installed at the lowest end interface of the double hollow rod center tube, sealed with the center tube by a sealing ring. Externally, it is connected and fixed to the double hollow rod center tube via threads. Circulating hot water enters from the wellhead center tube joint 1, passes through the device body 2 and the conical sealing top rod 3 to form an annular space, and finally flows back to the wellhead. This achieves unidirectional circulation of hot water, ensuring normal production. During the reverse circulation process of the leak detection device, the conical sealing top rod 3 controls the flow of hot water and closes the circulation channel. If there is no overflow when the center tube vent valve is opened at the wellhead and the pressure at the double hollow rod circulation inlet does not drop, it can be determined that the tubing is intact and leak-free. If the pressure drops and there is overflow at the outlet, there is a leak in the center tube. The well fault point can be determined by combining this with the well load data. After well completion, hot water is introduced through the circulation outlet for pressure testing; no leakage at the center tube outlet indicates a pass. During normal production, this operation can also be used to verify whether the central tube is leaking when data is abnormal.

[0019] The above are merely preferred embodiments of this utility model, but the scope of protection of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the scope of protection of this utility model.

Claims

1. A leak detection device for a central tube with double hollow rods, connected to a central tube with double hollow rods, characterized in that, It includes: a central pipe connector (1), a device body (2) and a conical sealing top rod (3). The upper end of the device body (2) is connected to the lower end of the central pipe connector (1) and forms a channel from the inlet to the outlet. The double hollow rod central pipe is connected to the central pipe connector (1), and the lower end interface of the double hollow rod central pipe is connected to the inlet of the channel. The conical sealing top rod (3) is housed in the fixed groove of the device body (2) and slides back and forth under the action of the elastic element. The top of the conical sealing top rod (3) abuts against the top of the fixed groove. When it slides to the bottom of the fixed groove, it opens the channel, and when it slides to the top of the fixed groove, it seals the channel.

2. The leak detection device for the central tube of a double hollow rod according to claim 1, characterized in that: The central pipe joint (1) is a hollow cylinder, and the upper part of the central pipe joint (1) is provided with a sealing ring for sealing the central pipe sealing groove (5) for connection.

3. The leak detection device for the central tube of a double hollow rod according to claim 1, characterized in that: The central pipe joint (1) has three Y-shaped external pipe threads (6) on its exterior.

4. The leak detection device for the central tube of a double hollow rod according to claim 1, characterized in that: The main body (2) of the device is a hollow cylinder with threads on the top.

5. A leak detection device for a central tube with double hollow rods according to claim 1, characterized in that: The conical sealing top rod (3) includes: a conical rod head (31) at the top and a cylindrical slide (32) at the bottom. A rod body is located between the rod head (31) and the slide (32), and an elastic element is sleeved on the rod body.

6. A leak detection device for a central tube with double hollow rods according to claim 5, characterized in that: The tapered sealing top rod (3) is made of corrosion-resistant downhole special carbon steel.

7. A leak detection device for a central tube with double hollow rods according to claim 1, characterized in that: The elastic element is a spring (4).

8. A leak detection device for a central tube with double hollow rods according to claim 7, characterized in that: The spring (4) is a corrosion-resistant spring.

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