A blowout preventer for oil wells

Abstract

The utility model discloses a kind of oil pipe blowout preventer plugging devices for oil well, including upper sleeve, lower sleeve, plugging core, elastic limiting mechanism and tension spring;Lower sleeve is installed on the lower end of upper sleeve by screw thread, and the barrel wall of lower sleeve is provided with multiple liquid inlet through holes;Elastic limiting mechanism is arranged on the barrel wall of upper sleeve, for plugging core is positioned and unlocked position;One end of tension spring is connected plugging core, and the other end is connected the bottom cover of lower sleeve, and plugging core is provided with downward tension by tension spring.Down plugging core has two kinds of state, in plugging state, fixed in the inside of upper sleeve by elastic limiting mechanism, and plugging the inside passage of upper sleeve;In falling state, plugging core is located lower sleeve bottom, and upper sleeve inside passage is punched through.

Description

Technical Field

[0001] This utility model belongs to the field of oil well construction technology, specifically relating to a blowout prevention and plugging device for oil well tubing. Background Technology

[0002] During the installation of tubing in an oil well, the tubing's interior is typically open. Therefore, if the bottom of the tubing is not sealed, oil and gas in the well can be forced upwards due to increased pressure, causing high-altitude oil and gas spraying, interrupting operations, and potentially leading to pollution or fire accidents, resulting in significant losses. Therefore, an easily operable sealing device is needed to block the bottom of the tubing, preventing oil and gas from spraying out of the open tubing during installation, thereby controlling pollution and accidents. Utility Model Content

[0003] The purpose of this invention is to overcome the shortcomings of the prior art and provide a blowout prevention and plugging device for oil well tubing.

[0004] This utility model is achieved through the following technical solution:

[0005] A blowout preventer for oil well tubing includes an upper sleeve, a lower sleeve, a plugging core, an elastic limiting mechanism, and a tension spring.

[0006] The lower sleeve is threaded onto the lower end of the upper sleeve, and the lower sleeve has multiple liquid inlet holes on its wall.

[0007] The sealing core has two states: sealing and falling. In the sealing state, it is fixed inside the upper sleeve by an elastic limiting mechanism, blocking the internal channel of the upper sleeve. In the falling state, the sealing core is located at the bottom of the lower sleeve, and the internal channel of the upper sleeve is open.

[0008] The sealing core is a cylinder with a conical surface at the top. Correspondingly, a limiting part is provided on the inner wall of the upper sleeve to limit the conical surface.

[0009] The elastic limiting mechanism is installed on the wall of the upper sleeve and is used to limit and unlock the sealing core. The elastic limiting mechanism includes a spring, a piston, a limiting post, a sliding sleeve, and an air passage. A transverse mounting cavity is provided on the wall of the upper sleeve. The outer end of the mounting cavity is open, and the inner end of the mounting cavity is closed. The spring, piston, limiting post, and sliding sleeve are all installed in the mounting cavity. The spring is located at the tail of the piston, and the front end of the piston is connected to the limiting post. The limiting post is arranged transversely. The sliding sleeve is fixedly installed at the port position of the mounting cavity, and the limiting post slides through the sliding sleeve. The air passage is arranged vertically. The upper port of the air passage is connected to the upper port of the upper sleeve, and the lower port of the air passage is connected to the mounting cavity. A concave hole corresponding to the position of the limiting post is provided on the outer wall of the sealing core.

[0010] One end of the tension spring is connected to the sealing core, and the other end is connected to the bottom cover of the lower sleeve. The tension spring provides downward tension to the sealing core.

[0011] In the above technical solution, the upper end of the upper sleeve is provided with an internal thread for connection with the bottom end of the oil pipe.

[0012] In the above technical solution, the outer diameter of the lower sleeve is smaller than the outer diameter of the upper sleeve.

[0013] In the above technical solution, a sealing ring is provided on the outer wall of the sealing core to achieve a seal between the sealing core and the inner wall of the upper sleeve.

[0014] In the above technical solution, a tension spring mounting cavity is provided at the bottom center of the sealing core, and the top of the tension spring is connected to the top of the tension spring mounting cavity; after the sealing core is lowered, the tension spring retracts into the tension spring mounting cavity, so that the sealing core is in stable contact with the bottom cover of the lower sleeve, ensuring the stability of the sealing core.

[0015] In the above technical solution, a hook is provided at the top center of the sealing core. By pulling the sealing core upward with the hook, the sealing core can be sealed.

[0016] The advantages and beneficial effects of this utility model are as follows:

[0017] This utility model's oil pipe anti-blowout sealing device effectively solves the problem of oil spraying during oil pipe lowering construction. During construction, the oil pipe anti-blowout sealing device is threadedly connected to the bottom end of the oil pipe to be lowered. During lowering, the sealing core of the device blocks the internal channel, preventing oil from entering the oil pipe. Once the oil pipe reaches the designated position, pressure is applied to the inside of the pipe, providing air pressure to the mounting cavity between the piston and the sliding sleeve through the air passage. This drives the piston to move outward, causing the piston to disengage the limiting pin from the concave hole of the sealing core, thus unlocking and limiting the sealing core. After unlocking and limiting, the sealing core falls to the bottom of the lower sleeve under the tension of the spring. After falling, the sealing core is positioned below the liquid inlet hole on the lower sleeve wall, and the spring retracts into the spring mounting cavity of the sealing core, ensuring stable contact between the sealing core and the bottom cover of the lower sleeve, guaranteeing the stability of the sealing core. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the oil pipe anti-blowout sealing device of this utility model (the sealing core is in the sealing state).

[0019] Figure 2 This is a schematic diagram of the structure of the oil pipe anti-blowout sealing device of this utility model (the sealing core is in the falling state).

[0020] Figure 3 This is a schematic diagram of the elastic limiting mechanism of the oil pipe anti-blowout sealing device of this utility model.

[0021] For those skilled in the art, other related figures can be obtained from the above figures without any creative effort. Detailed Implementation

[0022] To enable those skilled in the art to better understand the present invention, the technical solution of the present invention will be further described below with reference to specific embodiments.

[0023] See appendix Figure 1 A blowout preventer for oil well tubing includes an upper sleeve 1, a lower sleeve 2, a plugging core 3, an elastic limiting mechanism 4, and a tension spring 5.

[0024] The upper sleeve 1 has an internal thread 101 at its upper end for connection to the bottom end of the oil pipe. The lower sleeve 2 is threaded onto the lower end of the upper sleeve 1. The lower sleeve 2 has multiple inlet holes 201 on its wall, allowing oil to enter the lower sleeve 2 and then flow upwards into the upper sleeve 1. Furthermore, the outer diameter of the lower sleeve 2 is smaller than the outer diameter of the upper sleeve 1.

[0025] The sealing core 3 has two states: sealing and falling. In the sealing state (see attached diagram) Figure 1 The sealing core 3 is fixed inside the upper sleeve 1 by the elastic limiting mechanism 4, sealing the internal channel of the upper sleeve 1 and preventing oil from entering the oil pipe; when it is necessary to switch to the falling state, the elastic limiting mechanism 4 unlocks the limiting position of the sealing core 3, and the sealing core 3 falls to the bottom of the lower sleeve 2 (attached). Figure 2 This opens up the internal channel of the upper sleeve 1, allowing the oil to pass through the upper sleeve 1 and enter the oil pipe upwards.

[0026] Specifically, the sealing core 3 is a column with a tapered surface 301 at its top that gradually decreases in diameter from bottom to top. Correspondingly, a limiting part 102 is provided on the inner wall of the upper sleeve 1 to limit the tapered surface 301, thereby preventing the sealing core 3 from moving upward. Two sealing rings 6 are provided on the outer wall of the sealing core 3 to achieve a seal between the sealing core 3 and the inner wall of the upper sleeve 1.

[0027] The elastic limiting mechanism 4 is installed on the cylinder wall of the upper sleeve 1, and is used to limit and unlock the sealing core 3. In the limited position, the elastic limiting mechanism 4 limits the sealing core 3 to prevent it from falling; in the unlocked position, the sealing core 3 falls. For details, see the appendix. Figure 3 The elastic limiting mechanism 4 includes a spring 401, a piston 402, a limiting post 403, a sliding sleeve 404, and an air passage 405. A transverse mounting cavity 103 is provided on the wall of the upper sleeve 1. The outer end of the mounting cavity 103 is open, and the inner end is closed. The spring 401, piston 402, limiting post 403, and sliding sleeve 404 are all installed within the mounting cavity 103. The spring 401 is located at the tail of the piston 402. The front end of 402 is connected to a limiting post 403, which is arranged horizontally. A sliding sleeve 404 is fixedly installed at the port position of the mounting cavity 103, and the limiting post 403 slides through the sliding sleeve 404. The air passage 405 is arranged vertically, with its upper port connected to the upper port of the upper sleeve 1 and its lower port connected to the mounting cavity 10. In addition, a concave hole 302 corresponding to the position of the limiting post 403 is provided on the outer wall of the sealing core 3. In the limited position, under the action of the spring 401, the outer end of the limiting post 403 is inserted into the concave hole 302 of the sealing core 3, thereby preventing the sealing core 3 from falling; when it is necessary to unlock the limited position, positive pressure is provided to the mounting cavity 10 between the piston 402 and the sliding sleeve 404 through the air passage 405, driving the piston 402 to move outward (compressing the spring 401), and the piston 402 drives the limiting post 403 to disengage from the concave hole 302 of the sealing core 3.

[0028] One end of the tension spring 5 is connected to the sealing core 3, and the other end is connected to the bottom cover 21 of the lower sleeve 2. The tension spring 5 provides downward tension to the sealing core 3. After the elastic limiting mechanism 4 unlocks and limits the sealing core 3, the sealing core 3 can fall smoothly to the bottom of the lower sleeve 2 under the tension of the tension spring 5.

[0029] Furthermore, a tension spring mounting cavity 303 is provided at the bottom center of the sealing core 3. The top of the tension spring 5 is connected to the top of the tension spring mounting cavity 303, so that after the sealing core 3 is lowered, the tension spring 5 can retract into the tension spring mounting cavity 303, thereby saving space at the bottom of the lower sleeve 2 (after the sealing core 3 is lowered, it should be located below the liquid inlet hole 201 on the wall of the lower sleeve 2, so as not to block the liquid inlet hole 201 and to avoid the oil flowing in from the liquid inlet hole 201 from causing an upward impact force on the sealing core 3. Therefore, the bottom of the lower sleeve 2 must have enough space to accommodate the sealing core 3. The design of the tension spring mounting cavity 303 of this utility model can effectively save space at the bottom of the lower sleeve 2), and make the sealing core 3 in stable contact with the bottom cover 21 of the lower sleeve 2, ensuring the stability of the sealing core 3 (without the tension spring mounting cavity 303, the tension spring 5 is equivalent to a protrusion, which will cause the sealing core 3 to be unstable).

[0030] Furthermore, a hook 304 is provided at the top center of the sealing core 3. By pulling the sealing core 3 upward through the hook 304, the sealing core 3 can reach the sealing state. That is, during the process of pulling the sealing core 3 upward, since the top of the sealing core 3 is a conical surface 301, the conical surface 301 can act on the limiting post 403 of the elastic limiting mechanism 4, compressing the spring 401 outward with the limiting post 403. When the sealing core 3 reaches the limiting position, the limiting post 403 is exactly aligned with the concave hole 302 on the sealing core 3. At this time, the spring 401 rebounds, pushing the limiting post 403 into the concave hole 302.

[0031] The method of using the oil pipe blowout prevention and plugging device of this utility model is as follows:

[0032] Step 1: First, pull the sealing core 3 upward using the hook 304 to achieve the sealing state. During the upward movement of the sealing core 3, since the top of the sealing core 3 is a conical surface 301, the conical surface 301 can act on the limiting post 403 of the elastic limiting mechanism 4 to compress the spring 401 outward. When the sealing core 3 reaches the limiting position, the limiting post 403 is aligned with the concave hole 302 on the sealing core 3. At this time, the spring 401 rebounds, pushing the limiting post 403 into the concave hole 302.

[0033] Step 2: Then, thread the upper end of the upper sleeve 1 to the bottom end of the oil pipe to be lowered.

[0034] Step 3: Lower the tubing into the well and to the designated location.

[0035] Step 4: After reaching the designated position, pressurize the oil pipe and provide air pressure to the mounting cavity 10 between the piston 402 and the sliding sleeve 404 through the air passage 405. Drive the piston 402 to move outward. The piston 402 drives the limiting post 403 to disengage from the concave hole 302 of the sealing core 3, thereby unlocking and limiting the sealing core 3. After the sealing core 3 is unlocked and limited, it falls smoothly to the bottom of the lower sleeve 2 under the tension of the tension spring 5. After falling, the sealing core 3 is located below the liquid inlet hole 201 on the wall of the lower sleeve 2, and the tension spring 5 is retracted in the tension spring mounting cavity 303 of the sealing core 3, so that the sealing core 3 is in stable contact with the bottom cover 21 of the lower sleeve 2, ensuring the stability of the sealing core 3.

[0036] For ease of explanation, spatial relative terms such as “up,” “down,” “left,” and “right” are used in the embodiments to describe the relationship of one element or feature shown in the figures relative to another element or feature. It should be understood that, in addition to the orientations shown in the figures, spatial terms are intended to include different orientations of the device in use or operation. For example, if the device in the figures is inverted, an element described as being “down” of other elements or features would be positioned “up” of those other elements or features. Therefore, the exemplary term “down” can encompass both up and down orientations. The device may be positioned in other ways (rotated 90 degrees or in other orientations), and the spatial relative descriptions used herein will be interpreted accordingly.

[0037] Moreover, relational terms such as “first” and “second” are used merely to distinguish one component from another that has the same name, without necessarily requiring or implying any such actual relationship or order between the components.

[0038] The present invention has been described above by way of example. It should be noted that, without departing from the core of the present invention, any simple modifications, alterations or other equivalent substitutions that can be made by those skilled in the art without creative effort fall within the protection scope of the present invention.

Claims

1. A blowout preventer for oil well tubing, characterized in that: It includes an upper sleeve, a lower sleeve, a sealing core, an elastic limiting mechanism, and a tension spring; The lower sleeve is threaded onto the lower end of the upper sleeve, and the lower sleeve has multiple liquid inlet holes on its wall. The sealing core has two states: sealing and falling. In the sealing state, it is fixed inside the upper sleeve by an elastic limiting mechanism, blocking the internal channel of the upper sleeve. In the falling state, the sealing core is located at the bottom of the lower sleeve, and the internal channel of the upper sleeve is open. The sealing core is a cylinder with a conical surface at the top. Correspondingly, a limiting part is provided on the inner wall of the upper sleeve to limit the conical surface. The elastic limiting mechanism is installed on the wall of the upper sleeve and is used to limit and unlock the sealing core. The elastic limiting mechanism includes a spring, a piston, a limiting post, a sliding sleeve, and an air passage. A transverse mounting cavity is provided on the wall of the upper sleeve. The outer end of the mounting cavity is open, and the inner end of the mounting cavity is closed. The spring, piston, limiting post, and sliding sleeve are all installed in the mounting cavity. The spring is located at the tail of the piston, and the front end of the piston is connected to the limiting post. The limiting post is arranged transversely. The sliding sleeve is fixedly installed at the port position of the mounting cavity, and the limiting post slides through the sliding sleeve. The air passage is arranged vertically. The upper port of the air passage is connected to the upper port of the upper sleeve, and the lower port of the air passage is connected to the mounting cavity. A concave hole corresponding to the position of the limiting post is provided on the outer wall of the sealing core. One end of the tension spring is connected to the sealing core, and the other end is connected to the bottom cover of the lower sleeve. The tension spring provides downward tension to the sealing core.

2. The blowout preventer for oil well tubing according to claim 1, characterized in that: The upper end of the upper sleeve is provided with an internal thread for connection to the bottom end of the oil pipe.

3. The blowout preventer for oil well tubing according to claim 1, characterized in that: The outer diameter of the lower sleeve is smaller than the outer diameter of the upper sleeve.

4. The blowout prevention and plugging device for oil well tubing according to claim 1, characterized in that: A sealing ring is provided on the outer wall of the sealing core to achieve a seal between the sealing core and the inner wall of the upper sleeve.

5. The blowout preventer for oil well tubing according to claim 1, characterized in that: A tension spring mounting cavity is provided at the bottom center of the sealing core, and the top of the tension spring is connected to the top of the tension spring mounting cavity; after the sealing core is lowered, the tension spring retracts into the tension spring mounting cavity.

6. The oil tubing blowout prevention and plugging device for oil wells according to claim 1, characterized in that: A hook is installed at the top center of the sealing core.

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