Wellhead blowout preventer for rod-pumped well

Abstract

The utility model relates to the technical field of oil field wellhead production devices, in particular to a rod-pumped well wellhead blowout preventer which comprises a blowout prevention gland body replacing an original wellhead sealing packing box top cover, a through penetrating hole is formed in the center of the blowout prevention gland body, a polish rod enters a well through the penetrating hole, and a hinged movable baffle is arranged in the blowout prevention gland body. And the movable baffle is upwards overturned to be buckled with the through hole of the blowout prevention gland. The utility model provides a rod-pumped well wellhead blowout preventer, which is characterized in that a top end gland of a wellhead sealing packing box is replaced by a blowout prevention gland main body, a movable baffle which is upwards turned over is arranged in the blowout prevention gland main body in a hinged manner, and after a polish rod is broken off, the movable baffle can be upwards turned over under the pressure of underground crude oil to be buckled with a blowout prevention gland through hole to seal a wellhead. And underground crude oil is prevented from being sprayed out from the top end of the wellhead sealing packing box after the polish rod is broken and falls off, and yield loss is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of oilfield wellhead production devices, in particular to a wellhead blowout prevention device for a pumping well. Background Art

[0002] During the production process of a pumping well, the wellhead sealing packing box is an important sealing device. By squeezing the packing downward to increase the pressure between the packing and the polished rod, the wellhead is sealed to ensure that the well fluid cannot leak out during normal production. In the prior art, the polished rod is susceptible to corrosion from the well fluid during long-term work underground. The corroded polished rod constantly rubs and collides with the packing and other components during the long-term work process, causing the polished rod to break and fall off. After the polished rod falls off, it will fall into the well and vacate the interface at the top of the wellhead sealing box. The crude oil at the bottom of the well will be sprayed out from the interface at the top of the wellhead packing box. Also sprayed out is part of the crude oil that flows back through the return oil pipeline in the metering room, resulting in a large-scale leakage of crude oil, a serious loss of crude oil production, and pollution to the surrounding environment, posing a major safety hazard. Therefore, in response to the above shortcomings, a wellhead blowout preventer for a pumping well is proposed. Summary of the Invention

[0003] The utility model aims to provide a wellhead blowout prevention device for a pumping well, so as to overcome the defect in the prior art that after the polished rod breaks and falls off, a large amount of crude oil in the well and in the metering room is ejected from the top interface of the wellhead sealing packing box, causing crude oil production loss and environmental pollution.

[0004] In order to achieve the above-mentioned purpose, the utility model provides a wellhead blowout prevention device for a pumping well, comprising:

[0005] A tubular blowout preventer gland body, wherein a cavity is provided in the blowout preventer gland body, wherein the bottom of the blowout preventer gland body is connected to the top end of the wellhead sealing packing box via a thread;

[0006] The center of the blowout preventer gland body is provided with a blowout preventer gland through-hole which runs through from top to bottom, and the polished rod passes downward into the blowout preventer gland through-hole and passes through the blowout preventer gland body;

[0007] A movable baffle is provided in the cavity of the blowout preventer gland body, and the movable baffle is hinged to the inner wall of the blowout preventer gland body to form an upside-down flip structure;

[0008] The size of the upper surface of the movable baffle matches the perforation of the anti-blowout pressure cover, and the movable baffle is turned upward and buckled with the perforation of the anti-blowout pressure cover.

[0009] Preferably, a connecting rod is provided on the edge of the movable baffle, the bottom end of the connecting rod is connected to the edge of the movable baffle, and the top end is hinged to the inner wall of the anti-blowout cover body.

[0010] Preferably, the connecting rod is bent upward, and the top end of the movable baffle is inclined outward when the movable baffle is in a stationary state.

[0011] Preferably, a connecting pin is provided at the hinged joint between the connecting rod and the blowout preventer cover body, the connecting pin passes through the top end of the connecting rod and both ends of the connecting pin are horizontally inserted into the inner wall of the blowout preventer cover body.

[0012] Preferably, a sealing ring is provided on the edge of the upper surface of the movable baffle.

[0013] Preferably, a pressure relief channel is provided on the side wall of the blowout prevention cover body, and a pressure relief plug is provided at the outlet of the pressure relief channel.

[0014] Preferably, an annular boss is provided on the inner wall of the bottom end of the blowout preventer cover body along the circumferential direction, a hole in the blowout preventer cover passes downward through the boss, and a downward guiding structure is provided on the inner edge of the upper surface of the boss.

[0015] Preferably, a handle is provided on the outer wall of the blowout preventer cover body, and the direction of the handle is perpendicular to the blowout preventer cover body.

[0016] The utility model provides a pumping well wellhead blowout prevention device with the following beneficial effects:

[0017] The utility model provides a blowout prevention device for a wellhead of a pumping well, wherein the top cover of a wellhead sealing packing box is replaced by a blowout prevention cover body, and a movable baffle which is hinged and flipped upward is provided inside. After the polished rod breaks off, the movable baffle will flip upward under the pressure of the downhole crude oil and engage with the perforated hole of the blowout prevention cover to seal the wellhead, thereby preventing the downhole crude oil from spraying out from the top of the wellhead sealing packing box after the polished rod breaks off, thereby reducing production losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is the structural diagram of the wellhead blowout preventer of the pumping well.

[0019] Legend:

[0020] 1. Handle; 2. Blowout preventer cover body; 3. Movable baffle; 4. Pressure relief plug; 5. Connecting pin; 6. Blowout preventer cover perforation. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0022] like Figure 1As shown, the present invention provides a wellhead blowout preventer device for a pumping well, comprising: a tubular blowout preventer gland body 2, wherein a cavity is defined within the blowout preventer gland body 2. The bottom of the blowout preventer gland body 2 is threadedly connected to the top of a wellhead sealing packing box. The blowout preventer gland body 2 serves as the main body of the device, providing support and mounting. After being connected to the wellhead sealing packing box, it replaces the original top cover of the wellhead sealing packing box. After the blowout preventer gland body 2 is rotated, the threads allow the blowout preventer gland body 2 to move up and down at the top of the wellhead sealing packing box, performing the same function as the original top cover of the wellhead sealing packing box. As the blowout preventer gland body 2 moves downward, it squeezes the packing within the wellhead sealing packing box, causing the packing to contract inward and squeeze the polished rod, thereby sealing the polished rod. During operation, if the polished rod breaks or falls off, the top of the blowout preventer gland body 2 automatically seals, preventing the crude oil and well fluid from flowing back upward and spraying out, causing crude oil production loss and environmental pollution.

[0023] Among them, the side wall of the blowout preventer gland body 2 is provided with a pressure relief channel, and the outlet of the pressure relief channel is provided with a pressure relief plug 4. After the polished rod breaks, the blowout preventer gland body 2 will seal the top to prevent the original oil and well fluid in the well from splashing. At this time, the crude oil and well fluid in the well inside the blowout preventer gland body 2 will accumulate in the cavity of the blowout preventer gland body 2, causing the internal hydraulic pressure to increase. Before handling the broken polished rod and installing a new polished rod, it is necessary to release the internal pressure first to prevent the crude oil and well fluid in the well from splashing again during the maintenance process. The pressure relief channel is used to connect the inside and outside of the blowout preventer gland body 2. During maintenance, it is only necessary to install the receiving equipment at the outlet of the pressure relief channel and then remove the pressure relief plug 4 to relieve the pressure inside the blowout preventer gland body 2.

[0024] It should be noted that a handle 1 is provided on the outer wall of the blowout preventer gland body 2, oriented perpendicularly to the blowout preventer gland body 2. This handle 1 is used to rotate the blowout preventer gland body 2. During operation, simply applying force to the blowout preventer gland body 2 causes the handle 1 to drive the blowout preventer gland body 2 to rotate synchronously, thereby adjusting the position of the blowout preventer gland body 2 at the top of the wellhead sealing box. During operation, the handle 1 forms a simple lever structure on the surface of the blowout preventer gland body 2, reducing the manpower required to adjust the blowout preventer gland body 2 and lowering the workload of the operator.

[0025] In the present invention, a blowout preventer cover through-hole 6 is provided in the center of the blowout preventer cover body 2, which passes through the blowout preventer cover through-hole 6 downwardly. The polished rod passes through the blowout preventer cover through-hole 6 through the blowout preventer cover body 2. The blowout preventer cover through-hole 6 is mainly used to provide space for the polished rod to pass through. After the blowout preventer cover body 2 is installed, the polished rod passes through the blowout preventer cover body 2 and the wellhead sealing packing box downwardly into the well, and moves up and down with the drive of the power motor to perform oil pumping. A movable baffle 3 is provided in the cavity of the blowout preventer cover body 2. The movable baffle 3 is hinged to the inner wall of the blowout preventer cover body 2 to form an up-and-down flipping structure. The upper surface size of the movable baffle 3 matches the blowout preventer cover through-hole 6. The movable baffle 3 flips upward and engages with the blowout preventer cover through-hole 6. The movable baffle 3 is inside the blowout preventer gland body 2. When the polished rod breaks, the downhole pressure will push the crude oil and well fluid in the well upward. At this time, the well fluid contacts the movable baffle 3. Under the thrust of the well fluid, the movable baffle 3 flips upward around the hinge with the blowout preventer gland body 2, sealing the blowout preventer gland perforation 6 from the inside, thereby preventing the crude oil and well fluid from splashing out of the well. When the movable baffle 3 closes the blowout preventer gland perforation 6, the blowout preventer gland 3 is mainly affected by its own gravity and the pressure of the downhole liquid. The pressure of the downhole liquid is usually much greater than the gravity of the movable baffle 3. Therefore, before the internal pressure of the blowout preventer gland body 2 is released, the blowout preventer gland 3 will always maintain a sealed state on the blowout preventer gland perforation 6, thereby preventing the wellhead from splashing when the polished rod breaks.

[0026] The movable baffle 3 is provided with a connecting rod at its edge, the bottom end of the connecting rod being connected to the edge of the movable baffle 3 and the top end being hinged to the inner wall of the blowout preventer gland body 2. The movable baffle 3 is hinged to the blowout preventer gland body 2 via the connecting rod. When the movable baffle 3 is opened, it hangs down under its own gravity below the connection with the blowout preventer gland body 2. The connecting rod keeps the connection between the movable baffle 3 and the blowout preventer gland body 2 away from the working position of the polished rod, preventing the movable baffle 3 and the polished rod from being too close to each other during normal operation, thereby preventing the two from contacting and wearing each other, or damaging the polished rod by colliding with each other, thereby improving the safety of the device.

[0027] Furthermore, the connecting rod is upwardly curved, and the top end of the movable baffle 3 is tilted outward when at rest. Due to the upward curvature of the connecting rod, the angle at which the movable baffle 3 hangs downward in the static state changes from perpendicular to the horizontal plane to an angle relative to the horizontal plane, and the tilt is outward relative to the blowout preventer cover body 2. When the fluid flowing upward downhole contacts the lower surface of the movable baffle 3, a constant force pushes the movable baffle 3 upward, making its movement more sensitive and improving the efficiency of sealing the blowout preventer cover perforation 6.

[0028] It should be noted that a connecting pin 5 is provided at the hinged joint between the connecting rod and the blowout preventer pressure cover body 2. The connecting pin 5 passes through the top of the connecting rod and the two ends of the connecting pin 5 are inserted into the inner wall of the blowout preventer pressure cover body 2 in the horizontal direction. The connecting rod realizes the hinged connection between the blowout preventer pressure cover body 2 and the movable baffle 3 through the connecting pin 5. Both ends of the connecting pin 5 are inserted into the inner wall of the blowout preventer pressure cover body 2, which can effectively improve the stability of the connection and prevent the movable baffle 3 from separating from the blowout preventer pressure cover body 2 during operation. In order to improve the sealing performance of the device, a sealing ring is usually provided on the edge of the upper surface of the movable baffle 3. After the movable baffle 3 is flipped upward to seal the blowout preventer pressure cover perforation 6, the sealing ring fills the gap between the movable baffle 3 and the blowout preventer pressure cover perforation 6 to prevent the underground liquid from flowing out from the gap between the two.

[0029] In addition, an annular boss is circumferentially formed on the inner wall of the bottom end of the blowout preventer gland body 2. A blowout preventer gland perforation 6 extends downward through the boss, and a downward guide structure is provided on the inner edge of the upper surface of the boss. During the lowering of the polished rod, after the polished rod enters the blowout preventer gland body 2, it contacts the wire structure of the lower boss. The guide structure guides the polished rod to the correct position, allowing it to smoothly extend downward into the packing, thereby ensuring the normal operation of the device and improving its stability.

[0030] During the blowout prevention process at the wellhead, after the polished rod breaks, the movable baffle 3, under the action of the pressure of the downhole liquid, immediately turns upward to seal the blowout prevention cover perforation 6, thereby achieving wellhead sealing, thus avoiding the oil splashing in the well caused by the staff's inability to find the polished rod break in time, and being able to always maintain the inlet seal under the action of the pressure difference before the downhole pressure is balanced. At this time, the pressure relief plug 4 is removed to open the pressure relief channel, and the downhole crude oil and well fluid flow out from the pressure relief channel. After the collecting device is placed at the outlet of the pressure relief channel to collect the well fluid flowing out, the pressure in the blowout prevention cover body 2 gradually decreases. When the pressure stabilizes, the movable baffle 3 gradually falls down and separates from the blowout prevention cover perforation 6 under the action of its own gravity, and the wellhead is opened. At this time, the downhole pressure has stabilized, and the well fluid and crude oil will not spray out from the wellhead. The wellhead device can be disassembled to salvage the broken polished rod or a new polished rod can be directly installed to continue oil production.

[0031] Combine Figure 1 The following is a detailed description of the steps of the pumping well blowout preventer:

[0032] Step 1: After assembling the device according to the device structure, install the blowout preventer gland body on the top of the wellhead sealing packing box to replace the top cover of the crude oil.

[0033] Step 2: Lower the polished rod into the well, tighten the blowout preventer gland, and then start the pumping unit to pump oil. During this process, the polished rod extends from top to bottom into the blowout preventer gland through-hole. The bottom end of the polished rod passes through the blowout preventer gland under the action of the internal guide structure of the blowout preventer gland and downward through the packing and into the well. The blowout preventer gland is tightened to squeeze the packing below so that the packing clamps the polished rod to seal it. The polished rod moves in the well under the drive of the pumping unit to pump oil.

[0034] Step 3: After a long period of operation, the polished rod is corroded and worn by the well fluid, breaking. The movable baffle is activated in time to seal the inlet to prevent the splashing of crude oil. After the polished rod breaks, it falls down along the wellhead into the well. The crude oil and well fluid flow upward under the action of the downhole pressure. When the crude oil and well fluid flow through the movable baffle, they push the movable baffle upward, causing it to flip upward and perforate the sealing cover, thus sealing the wellhead.

[0035] Step 4: Open the pressure relief plug to release the pressure. After the pressure relief plug is opened, the pressure relief channel is connected to the blowout preventer gland body. The internal high-pressure liquid flows out of the pressure relief channel to reduce the pressure inside the blowout preventer gland body. When the pressure gradually decreases and balances with the external pressure, the movable baffle falls back to its original position under the action of its own gravity.

[0036] Step 5: After the pressure stabilizes, dismantle the wellhead assembly and salvage the polished rod or directly install a new polished rod to start pumping oil according to work requirements.

[0037] Finally, it should be noted that the above is only a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art can still modify the technical solutions described in the aforementioned embodiments or make equivalent replacements for some of the technical features therein. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A blowout prevention device for a pumping well, characterized in that: include: A tubular blowout preventer gland body (2), wherein a cavity is provided in the blowout preventer gland body (2), and the bottom of the blowout preventer gland body (2) is connected to the top of the wellhead sealing packing box via a thread; The center of the blowout preventer cover body (2) is provided with a blowout preventer cover through-hole (6) which passes through the blowout preventer cover body (2); the polished rod passes downward through the blowout preventer cover through-hole (6) and passes through the blowout preventer cover body (2); A movable baffle (3) is provided in the cavity of the blowout prevention cover body (2), and the movable baffle (3) is hinged to the inner wall of the blowout prevention cover body (2) to form an upside-down flip structure; The upper surface size of the movable baffle (3) matches the blowout-proof pressure cover perforation (6), and the movable baffle (3) is turned upward to engage with the blowout-proof pressure cover perforation (6).

2. The blowout prevention device for a pumping well according to claim 1, characterized in that: A connecting rod is provided on the edge of the movable baffle (3), the bottom end of the connecting rod is connected to the edge of the movable baffle (3), and the top end is hinged to the inner wall of the anti-blowout pressure cover body (2).

3. The blowout prevention device for a pumping well according to claim 2, characterized in that: The connecting rod is bent upward, and the top end of the movable baffle (3) is tilted outward in a stationary state.

4. The blowout prevention device for a pumping well according to claim 3, characterized in that: A connecting pin (5) is provided at the hinged joint between the connecting rod and the blowout preventer cover body (2). The connecting pin (5) passes through the top end of the connecting rod, and both ends of the connecting pin (5) are inserted into the inner wall of the blowout preventer cover body (2) in a horizontal direction.

5. The blowout prevention device for a pumping well according to claim 4, characterized in that: A sealing ring is provided on the edge of the upper surface of the movable baffle (3).

6. The blowout prevention device for a pumping well according to claim 5, characterized in that: A pressure relief channel is provided on the side wall of the blowout prevention cover body (2), and a pressure relief plug (4) is provided at the outlet of the pressure relief channel.

7. The blowout prevention device for a pumping well according to claim 6, characterized in that: The inner wall of the bottom end of the anti-blowout cover body (2) is provided with an annular boss along the circumferential direction, the anti-blowout cover through-hole (6) passes through the boss downward, and the inner edge of the upper surface of the boss is provided with a downward guide structure.

8. The blowout prevention device for a pumping well according to claim 7, characterized in that: The outer wall of the blowout prevention cover body (2) is provided with a handle (1), and the direction of the handle (1) is perpendicular to the blowout prevention cover body (2).

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