Shock absorbing device for preventing hydraulic packer from losing seal at the moment of ball seat falling

Abstract

The utility model relates to a shock damper for preventing hydraulic packer from losing sealing at the moment of ball seat knockdown, including upper joint, compression spring, middle joint, rubber tube assembly, rubber tube back ring, mandrel and lower joint, the outside of upper joint lower extreme is provided with middle joint, and the inside of upper joint lower extreme is equipped with spring seat, and the inside of middle joint is equipped with the reduced diameter step, and the lower part of middle joint is equipped with rubber tube assembly, and the lower extreme of rubber tube assembly is equipped with rubber tube back ring, and middle joint, rubber tube assembly and rubber tube back ring are covered in the outside of mandrel, and the upper end of mandrel is equipped with the limit ring, and the middle part of mandrel is equipped with the pressure transmission hole, and the outer diameter of limit ring is less than the inner diameter of middle joint and greater than the inner diameter of reduced diameter step, and limit ring is used in cooperation with reduced diameter step, and the compression spring is equipped between limit ring and spring seat, and the compression spring is covered in the outside of spring seat and mandrel upper end, and the lower extreme of mandrel is equipped with lower joint. The utility model solves the problem of hydraulic packer supporting ball seat knockdown at the moment, and the problem of hydraulic packer losing sealing caused by the upward force of pipe column.

Description

Technical Field

[0001] This utility model relates to the field of oil and gas well operations, and more specifically, to a shock-absorbing device to prevent the hydraulic packer from losing its seal momentarily when it knocks off the ball seat. Background Technology

[0002] Hydraulic packers are commonly used in reservoir stimulation, well testing, and completion operations to protect the upper casing or seal leaks in the upper casing, ensuring wellbore safety or high-efficiency oil production. During setting, a setting ball seat is required, and the shear value of the setting ball seat pin must be higher than the complete setting pressure of the hydraulic packer. After successful setting and sealing, high pressure is injected into the tubing to knock off the ball seat to clear the oil and gas flow path. At the moment the setting ball seat knocks off, a reaction force exists on the tubing string. This reaction force pushes the tubing string above the setting ball seat. Under the combined effect of the bulging effect, the hydraulic packer mandrel experiences an upward impact force. If this upward force exceeds the design value of the hydraulic packer's release pin, it will cause premature loss of sealing. Summary of the Invention

[0003] The technical problem to be solved by this utility model is to provide a shock-absorbing device to prevent the hydraulic packer from losing its seal momentarily when it is knocked down from the ball seat. This solves the problem that the hydraulic packer loses its seal prematurely when the ball seat of the hydraulic packer is knocked down, due to the upward force on the tubing.

[0004] The technical solution adopted by this utility model to solve its technical problem is as follows: A shock-absorbing device is constructed to prevent the hydraulic packer from instantly losing its seal when it hits the ball seat. This device includes an upper connector, a compression spring, an intermediate connector, a rubber sleeve assembly, a rubber sleeve back ring, a mandrel, and a lower connector. The intermediate connector is located on the outer side of the lower end of the upper connector, and a spring seat is located inside the lower end of the upper connector. A diameter-reducing step is provided inside the intermediate connector. The rubber sleeve assembly is located at the lower part of the intermediate connector, and a rubber sleeve back ring is located at the lower end of the rubber sleeve assembly. The intermediate connector, the rubber sleeve assembly, and the rubber sleeve back ring are fitted around the mandrel. A limiting ring is provided at the upper end of the mandrel. A pressure transmission hole is provided in the middle of the shaft. The outer diameter of the limiting ring is smaller than the inner diameter of the intermediate joint and larger than the inner diameter of the reduced diameter step. The limiting ring is used in conjunction with the reduced diameter step. A compression spring is provided between the limiting ring and the spring seat. The compression spring is sleeved on the outside of the upper end of the spring seat and the mandrel. A lower joint is provided at the lower end of the mandrel. The intermediate joint is fixedly connected to the upper joint. The spring seat is fixedly connected to the upper joint. The intermediate joint is fixedly connected to the rubber sleeve assembly. The rubber sleeve assembly is fixedly connected to the rubber sleeve back ring. The mandrel is fixedly connected to the lower joint.

[0005] According to the above scheme, the upper part of the upper connector is provided with an oil pipe female thread, and the intermediate connector is connected to the upper connector by a thread.

[0006] According to the above scheme, a locking screw is provided at the connection between the intermediate joint and the upper joint.

[0007] According to the above scheme, the spring seat and the upper connector are connected by threads.

[0008] According to the above scheme, the intermediate joint is connected to the rubber sleeve assembly by threaded connection.

[0009] According to the above scheme, the rubber sleeve assembly and the rubber sleeve back ring are connected by threads.

[0010] According to the above scheme, the mandrel and the lower connector are connected by threads, and the lower end of the lower connector is provided with an oil pipe male thread.

[0011] According to the above scheme, the upper connector and the intermediate connector are sealed by an O-ring, the intermediate connector and the rubber sleeve assembly are sealed by an O-ring, the rubber sleeve assembly and the rubber sleeve back ring are sealed by an O-ring, the rubber sleeve back ring and the mandrel are sealed by an O-ring, and the mandrel and the lower connector are sealed by an O-ring.

[0012] The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in this utility model, has the following beneficial effects:

[0013] 1. This utility model utilizes a designed rubber sleeve. During positive pressurization, hydraulic pressure enters the rubber sleeve through the pressure transmission hole on the mandrel, causing the rubber sleeve to expand. After expansion, the rubber sleeve anchors to the inner wall of the casing or the open hole wall, preventing the tubing string from moving. When the pressure value continues to rise and knocks down the ball seat, the rubber sleeve continues to anchor to the inner wall of the casing or the open hole wall, transmitting the upward reaction force of the tubing string at the moment of knocking down the ball seat to the casing or the open hole wall. This greatly offsets the impact on the hydraulic packer mandrel, preventing the hydraulic packer mandrel from being stressed and unsealed. Subsequently, the hydraulic pressure acting inside the rubber sleeve disappears, and the rubber sleeve gradually returns to its original state.

[0014] 2. This utility model incorporates a compression spring between the limiting ring and the spring seat. Upon impact with the ball seat, the spindle tends to move upwards. The compression spring stores elastic potential energy to counteract the impact force generated by the upward movement of the spindle, thus working in conjunction with the rubber sleeve to dampen vibrations and improve the stability of the damping device. Simultaneously, the spring force prevents the spindle from moving, avoiding wear on the O-ring seal between the rubber sleeve back ring and the spindle, ensuring reliable sealing of the damping device. Attached Figure Description

[0015] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0016] Figure 1This is a structural schematic diagram of the shock-absorbing device of this utility model to prevent the hydraulic packer from losing its seal instantly when it hits the ball seat;

[0017] Figure 2 yes Figure 1 Enlarged schematic diagram of the intermediate damping device;

[0018] Figure 3 This is a schematic diagram of the shock-absorbing device of this utility model that prevents the hydraulic packer from losing its seal momentarily when it hits the ball seat.

[0019] Explanation of reference numerals in the attached diagram: 1-Upper connector; 2-Locking screw; 3-O-ring seal; 4-Spring seat; 5-Compression spring; 6-Intermediate connector; 7-Limiting ring; 8-Reduced diameter step; 9-Roller assembly; 10-Roller back ring; 11-Mandrel; 12-Lower connector; 13-Pressure transmission hole. Detailed Implementation

[0020] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0021] like Figure 1-2 As shown, the shock-absorbing device of this utility model for preventing the hydraulic packer from losing its seal instantly when it hits the ball seat includes an upper connector 1, a compression spring 5, an intermediate connector 6, a rubber tube assembly 9, a rubber tube back ring 10, a spindle 11, a lower connector 12, an "O" ring seal 3, and a locking screw 2.

[0022] The upper connector 1 has an oil pipe female thread on its upper part, an intermediate connector 6 on its lower external part, and a spring seat 4 on its lower internal part. The intermediate connector 6 has a reduced diameter step 8 inside, and a rubber sleeve assembly 9 on its lower part. The rubber sleeve assembly 9 has a rubber sleeve back ring 10 on its lower end. The intermediate connector 6, the rubber sleeve assembly 9, and the rubber sleeve back ring 10 are fitted onto the outside of the mandrel 11. The mandrel 11 has a limiting ring 7 on its upper end and a pressure transmission hole 13 in its middle.

[0023] During pressurization, hydraulic pressure enters the rubber sleeve through the pressure transmission hole 13 on the mandrel 11, causing the rubber sleeve to expand. After expansion, the rubber sleeve anchors to the inner wall of the casing or the open hole wall, preventing the tubing string from moving. When the pressure value continues to rise and knocks down the ball seat, the rubber sleeve continues to anchor to the inner wall of the casing or the open hole wall, transmitting the upward reaction force of the tubing string at the moment of knocking down the ball seat to the casing or the open hole wall. This greatly offsets the impact on the hydraulic packer mandrel 11, preventing the hydraulic packer mandrel 11 from being unsealed due to force. Subsequently, the hydraulic pressure acting inside the rubber sleeve disappears, and the rubber sleeve gradually returns to its original state.

[0024] The outer diameter of the limiting ring 7 is smaller than the inner diameter of the intermediate joint 6 but larger than the inner diameter of the reduced-diameter step 8. The limiting ring 7 works in conjunction with the reduced-diameter step 8. A compression spring 5 is provided between the limiting ring 7 and the spring seat 4. The compression spring 5 is sleeved on the outer side of the spring seat 4 and the upper end of the spindle 11. At the moment the ball seat is struck, the spindle 11 tends to move upward. The compression elastic potential energy stored in the compression spring 5 counteracts the impact force generated by the upward movement of the spindle 11, thus working with the rubber sleeve to absorb shock and improve the stability of the shock absorption device. At the same time, the elastic force of the compression spring 5 prevents the spindle 11 from moving, avoiding wear on the "O"-ring seal 3 between the rubber sleeve back ring 10 and the spindle 11, ensuring the reliable sealing of the shock absorption device.

[0025] The lower end of the spindle 11 is provided with a lower connector 12, and the lower end of the lower connector 12 is provided with an oil pipe male thread.

[0026] The intermediate connector 6 is connected to the upper connector 1, the spring seat 4 is connected to the upper connector 1, the intermediate connector 6 is connected to the rubber sleeve assembly 9, the rubber sleeve assembly 9 is connected to the rubber sleeve back ring 10, and the spindle 11 is connected to the lower connector 12 via threaded connections. A locking screw 2 is provided between the intermediate connector 6 and the upper connector 1.

[0027] The upper connector 1 is sealed to the intermediate connector 6, the intermediate connector 6 is sealed to the rubber tube assembly 9, the rubber tube assembly 9 is sealed to the rubber tube back ring 10, the rubber tube back ring 10 is sealed to the mandrel 11, and the mandrel 11 is sealed to the lower connector 12 by the “O” ring 3.

[0028] This utility model also provides a method for operating a shock-absorbing device to prevent the hydraulic packer from instantly losing its seal when it hits the ball seat, including the following steps:

[0029] 1) Select a damping device with an appropriate bore diameter based on the outer diameter of the steel ball that is matched with the seat.

[0030] 2) Move the mandrel to the lowest point so that the lower end face of the upper mandrel is in contact with the upper end face of the limiting retaining ring;

[0031] 3) Connect the pressure testing fixture to the internal thread of the upper oil pipe and the external thread of the lower oil pipe of the lower mandrel respectively. Sleeve a sleeve with an inner diameter slightly larger than the outer diameter of the shock absorber outside the shock absorber and put the rubber sleeve assembly inside the sleeve.

[0032] 4) Connect the test pump and conduct an overall sealing test on the shock absorber to ensure that there is no leakage during pressure testing and that the packer is properly seated.

[0033] 5) The upper and lower threads of the shock absorber should be tightened to the standard torque before being lowered into the well;

[0034] 6) When the completion string is lowered to the design position, drop the steel ball. After the steel ball is seated, inject well fluid into the tubing. After the hydraulic packer is set and verified to be sealed, continue injecting well fluid to set the ball seat and seal the ball seat.

[0035] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims. All of these forms are within the protection scope of the present invention.

Claims

1. A shock-absorbing device to prevent the hydraulic packer from instantly losing its seal when it hits the ball seat, characterized in that, The device includes an upper connector, a compression spring, an intermediate connector, a rubber sleeve assembly, a rubber sleeve back ring, a mandrel, and a lower connector. The intermediate connector is located on the outer side of the lower end of the upper connector, and a spring seat is located inside the lower end of the upper connector. A diameter-reducing step is located inside the intermediate connector. The rubber sleeve assembly is located at the lower part of the intermediate connector, and a rubber sleeve back ring is located at the lower end of the rubber sleeve assembly. The intermediate connector, rubber sleeve assembly, and rubber sleeve back ring are fitted onto the outside of the mandrel. A limiting ring is located at the upper end of the mandrel, and a pressure-transmitting hole is located in the middle of the mandrel. The outer diameter of the limiting ring is smaller than the inner diameter of the intermediate connector but larger than the inner diameter of the diameter-reducing step. The limiting ring cooperates with the diameter-reducing step. A compression spring is located between the limiting ring and the spring seat, and the compression spring is fitted onto the outer side of the spring seat and the upper end of the mandrel. A lower connector is located at the lower end of the mandrel. The intermediate connector is fixedly connected to the upper connector, the spring seat is fixedly connected to the upper connector, the intermediate connector is fixedly connected to the rubber sleeve assembly, the rubber sleeve assembly is fixedly connected to the rubber sleeve back ring, and the mandrel is fixedly connected to the lower connector.

2. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 1, is characterized in that... The upper connector is provided with an oil pipe female thread, and the intermediate connector is connected to the upper connector by a thread.

3. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 2, is characterized in that... The connection between the intermediate joint and the upper joint is provided with a locking screw.

4. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 1, is characterized in that... The spring seat and the upper connector are connected by a threaded connection.

5. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 1, is characterized in that... The intermediate connector is connected to the rubber sleeve assembly via threaded connections.

6. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it knocks off the ball seat, as described in claim 1, is characterized in that... The rubber sleeve assembly is connected to the rubber sleeve back ring by a threaded connection.

7. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 1, is characterized in that... The mandrel is connected to the lower connector by a threaded connection, and the lower connector has a male thread for oil pipes at its lower end.

8. The shock-absorbing device for preventing the hydraulic packer from instantly losing its seal when it hits the ball seat, as described in claim 1, is characterized in that... The upper connector and the intermediate connector are sealed by an O-ring, the intermediate connector and the rubber sleeve assembly are sealed by an O-ring, the rubber sleeve assembly and the rubber sleeve back ring are sealed by an O-ring, the rubber sleeve back ring and the mandrel are sealed by an O-ring, and the mandrel and the lower connector are sealed by an O-ring.

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