CN114592819B

CN114592819B - Oil pumping machine well head high molecular composite particle multistage sealing device

Info

Publication number: CN114592819B
Application number: CN202210338824.4A
Authority: CN
Inventors: 高帅
Original assignee: Daqing Dannuo Petroleum Technology Development Co ltd
Current assignee: Daqing Dannuo Petroleum Technology Development Co ltd
Priority date: 2022-04-01
Filing date: 2022-04-01
Publication date: 2022-07-22
Anticipated expiration: 2042-04-01
Also published as: CN114592819A

Abstract

A multi-stage sealing device of polymer composite particles at a wellhead of a pumping unit relates to the field of wellhead sealing devices and comprises a sealing box, a blowout preventer, a following offset follower and a blowout preventer, wherein the sealing box comprises a shell A, an annular air bag and flexible polymer composite spherical particles, the air bag is positioned in the shell A, the flexible polymer composite spherical particles are filled in the inner side of the annular of the air bag, the upper part of the air bag is communicated with an air release pipe, and the lower part of the air bag is communicated with a liquid inlet pipe; the blowout preventer comprises a shell B, a sealing flashboard A and a sealing flashboard B, wherein two vertical parallel-arranged sealing partition plates are connected in the shell B in a sealing mode, an inner cavity of the shell B is divided into three chambers by the two sealing partition plates, the sealing flashboard A and the sealing flashboard B are both located in the middle chamber, arc-shaped notches are formed in the close surfaces of the sealing flashboard A and the sealing flashboard B, and overlapping edges are formed in the two ends of the arc-shaped notches of the sealing flashboard A and the sealing flashboard B. The invention upgrades and improves the existing wellhead sealing device of the pumping unit, and is more suitable for the actual use requirement.

Description

Oil pumping machine well head high molecular composite particle multistage sealing device

Technical Field

The invention belongs to the field of wellhead sealing devices, and particularly relates to a multistage sealing device for polymer composite particles at a wellhead of an oil pumping unit.

Background

The traditional wellhead sealing device for the polished rod of the oil pumping unit mainly comprises a packing box, a well plugging device, a following device, a blowout preventer and the like, wherein the packing box plays a role in polished rod sealing; when the packing is replaced, the well plugging device needs to be closed, the well is temporarily plugged, and well fluid is prevented from leaking out when the packing is replaced; the follower can compensate 10-20mm of horizontal displacement of the polished rod and compensate vertical swing at a certain angle; when the polish rod breaks down, the blowout preventer is automatically closed, and oil leakage of the blowout preventer is prevented.

The traditional wellhead sealing device of the pumping unit has many defects, such as: 1. the main reasons for the short sealing period of the traditional packing box (the average sealing period of a normal water drive oil well is about 30 days, the average sealing period of a ternary drive oil well and a polymer drive oil well is about one week to 10 days, and the average sealing period of an individual well is about 3 days) are that the sealing flexibility between the packing and the polish rod is small, and the polish rod and the packing are in eccentric wear. 2. The traditional blowout preventer is sealed by two semicircular plates and forms polished rod seal (the two semicircular plates are respectively connected through bolts to drive the two semicircular plates to move left and right), but the well sealing effect is not ideal, mainly because the sealing plate is not only sealed with the polished rod, but also sealed with another sealing plate in butt joint, so as long as the sealing plate is abutted to the arc-shaped sealing surface of the polished rod or the abutting surfaces of the two semicircular plates, the other sealing surface is abutted to the target position difficultly. 3. The well closing plug is hinged in the traditional blowout preventer, the hinged shaft is provided with a torsion spring, in order to realize rapid well closing, the torsion force of the torsion spring is usually large, the well closing plug rotates to open after a polished rod is inserted into the blowout preventer, but the well closing plug always generates friction with the polished rod in the reciprocating motion process of the polished rod, the friction not only can cause the polished rod to generate single-side eccentric wear, but also can cause the well closing plug to be damaged due to friction, so that the well closing is not tight after the polished rod is broken.

Disclosure of Invention

In order to solve the problems that a packing box is short in service cycle and a blowout preventer is not ideal in sealing, the invention provides a polymer composite particle multistage sealing device for a wellhead of a pumping unit. The sealing flashboards of the blowout preventer do not have abutting surfaces but have overlapping surfaces, and the overlapping surfaces are sealed through the top pins, so that the sealing performance is improved.

The technical scheme provided by the invention is as follows: a multi-stage sealing device for polymer composite particles at a wellhead of an oil pumping unit comprises a sealing box, a well plugging device, a following-up follower and a blowout preventer, wherein the sealing box comprises a shell A, an annular air bag and flexible polymer composite spherical particles, the air bag is positioned in the shell A, the flexible polymer composite spherical particles are filled in the annular inner side of the air bag, the upper part of the air bag is communicated with an air release pipe, the lower part of the air bag is communicated with a liquid inlet pipe, the air release pipe is connected with a pressure relief one-way valve in series, the other end of the liquid inlet pipe is connected with a hydraulic cylinder, a piston is arranged in the hydraulic cylinder, liquid in the cylinder is pressed into the liquid inlet pipe through the piston, and the liquid inlet pipe is connected with the liquid inlet one-way valve in series; the well sealing device comprises a shell B, a sealing flashboard A and a sealing flashboard B, wherein two vertical sealing partition boards which are arranged in parallel are connected in the shell B in a sealing way, the inner cavity of the shell B is divided into three chambers by the two sealing partition boards, the sealing flashboard A and the sealing flashboard B are both positioned in the middle chamber, the approach surfaces of the sealing flashboard A and the sealing flashboard B are respectively provided with an arc notch, both ends of the arc notch of the sealing flashboard A and the arc notch of the sealing flashboard B are respectively provided with a lapping edge, both sides of the two sealing partition boards are respectively provided with a long hole for communicating the middle chamber and the chambers at both sides, the side surface of each sealing flashboard is respectively and fixedly connected with two guide boards, the guide boards respectively extend into the chambers at both sides through the long holes, the two guide boards in each chamber are simultaneously and rotatably connected with a stud with opposite in the rotating direction, one end of the stud extends out of the shell B and is rotatably sealed with the shell B, and the end part of the stud extending out of the shell B is fixedly connected with a driven rotating wheel, install the drive runner on the casing B, drive runner and driven runner meshing, the casing upper end and the lower extreme of overlap joint behind two sealed flashboard locks rigid coupling respectively have short set, it has the knock pin to slide sealed grafting respectively in the short set, the knock pin lower extreme rigid coupling respectively has the sloping block, the sloping block of upside supports through the inclined plane with sealed flashboard B up end, the sloping block of downside supports through the inclined plane with sealed flashboard A lower terminal surface, the short set of one end threaded connection who keeps away from sealed flashboard has adjusting nut, be provided with pressure spring between adjusting nut lower extreme and the knock pin.

The technical scheme is as follows: the blowout preventer comprises a shell C, wherein a blowout preventing seat is arranged in the shell C, the blowout preventing seat is provided with a central hole for a polished rod to pass through, the lower end of the blowout preventing seat is hinged with a blowout preventing cover, a strong torsion spring is arranged on a hinged shaft, the blowout preventing cover covers the blowout preventing seat under the action of the torsion spring so as to play a blowout preventing role, the blowout preventing seat is provided with an axial hole, a trigger pin is arranged in the hole in a sliding mode, the end part, far away from the polished rod, of the axial hole is connected with a plug in a threaded mode, a trigger spring is arranged between the plug and the trigger pin, the trigger pin has a tendency of sliding to the center of the blowout preventing seat under the action of the trigger spring, one end, far away from the polished rod, of the trigger pin is provided with a clamping block with a bulge, the blowout preventing cover is connected with a guy rope, the other end of the guy rope is connected with a supporting block with a recess, the supporting block leans against the shell C, and the bulge of the clamping block is clamped in the recess of the supporting block so as to limit the movement of the supporting block; the trigger pin is provided with an annular groove, the blowout prevention seat is provided with an axial limiting inserted rod, and the limiting inserted rod is inserted into the annular groove so as to limit the trigger pin.

The technical scheme is as follows: the air bag air-conditioning device is characterized by further comprising a controller, a pressure sensor is arranged between the shell A and the air bag, the piston rod of the piston is controlled to move through the motor, the output end of the pressure sensor is connected with the input end of the controller, and the output end of the controller is connected with the motor.

The beneficial effects of the invention are as follows:

1. in the invention, along with the change of seasons or weather, when the air temperature is reduced from high, the air pressure in the air bag is reduced along with the reduction of the temperature, when the pressure sensor detects that the pressure value of the air bag is less than a set value, the controller starts the motor, the motor pushes the piston to move downwards, the liquid in the hydraulic cylinder is extruded into the air bag, and the air pressure in the air bag is supplemented; when the pressure sensor detects that the pressure value of the air bag is larger than the set value, the controller turns off the motor, the piston stops pressing, and the air bag is not pressed. On the contrary, when the air temperature rises from low, the air pressure in the air bag increases along with the rise of the temperature, and when the pressure is greater than the set value, the pressure relief one-way valve automatically opens to keep the pressure intensity in the air bag not to exceed the set value all the time.

2. Two half sealing flashboards of the traditional blowout preventer need to be adjusted by two bolts, and the two sealing flashboards need to be synchronously adjusted, so that the traditional blowout preventer is very inconvenient.

3. The two half sealing flashboards of the traditional blowout preventer need to be abutted and sealed with a polished rod and abutted and sealed between two sealing flashboards, so that in the process of pushing the sealing flashboards, if one sealing surface is abutted in place, the flashboards are difficult to push so that the other sealing surface is abutted in place, and the problem of poor sealing exists.

4. In order to improve the well closing speed of the blowout preventer when a rod is broken, the torsion force of a torsion spring at the blowout prevention cover of the traditional blowout preventer is larger, so that a larger friction force exists between the polished rod and the blowout prevention cover when the polished rod normally reciprocates, the friction force at the position damages the polished rod and the blowout prevention cover, and in order to thoroughly avoid the friction force at the position, the triggering structure is designed. Compared with the existing blowout preventer, the blowout preventer provided by the invention not only ensures the closing speed of the blowout preventer, but also thoroughly avoids the friction problem between the blowout preventer and the polish rod, and thoroughly solves the friction damage problem.

Drawings

Fig. 1 is a schematic view of the overall structure of the present invention.

Fig. 2 is a schematic structural view of the sealing case of the present invention.

FIG. 3 is a cross-sectional view of a blowout preventer of the present invention.

FIG. 4 is a top view of the blowout preventer of the present invention.

FIG. 5 is a schematic diagram of the configuration of the blowout preventer of the present invention.

In the figure: 1. a sealing box; 2. a blowout preventer; 3. a blowout preventer; 4. a follower following along with the deviation; 101. an electric motor; 102. a piston; 103. a pressure sensor; 104. a hydraulic cylinder; 105. a liquid inlet pipe; 106. a liquid inlet check valve; 107. a nylon centralizing sleeve; 108. a shell A; 109. an air bag; 110. flexible polymer composite spherical particles; 111. an air escape pipe; 112. a pressure relief check valve; 201. a housing B; 202. sealing the gate plate A; 203. short sleeve; 204. driving the rotating wheel; 205. sealing the gate plate B; 206. a sloping block; 207. a knock pin; 208. a compression spring; 209. adjusting the nut; 210. a guide plate; 211. a stud; 212. a driven runner; 213. sealing the partition plate; 301. a housing C; 302. a resisting block; 303. a clamping block; 304. a plug; 305. a trigger spring; 306. a trigger pin; 307. a limiting inserted rod; 308. a blowout preventer seat; 309. rope stretching; 310. and (4) an anti-spraying cover.

Detailed Description

In order to make the technical problems, technical solutions and advantageous effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The embodiment comprises sealing boxes 1, a blowout preventer 2, a following follower 4 and a blowout preventer 3, wherein the number of the sealing boxes 1 is 2 or more than two, and therefore when a polished rod moves up and down, the sealing boxes 1 realize two-stage or three-stage flexible dynamic sealing on the polished rod. The seal box 1, the blowout preventer 2, the following follower 4 and the blowout preventer 3 are sequentially connected into a whole from top to bottom, and a channel for a light rod to pass through is arranged in the center of each component.

Different from the traditional packing box structure, as shown in fig. 2, the sealing box 1 of the present embodiment includes a casing a108, an annular air bag 109 and flexible polymer composite spherical particles 110, the air bag 109 is located in the casing a108 and is attached to the inner wall of the casing a108, the flexible polymer composite spherical particles 110 are filled inside the annular air bag 109, the flexible polymer composite spherical particles 110 are round spherical particles, the flexible polymer composite spherical particles 110 are directly contacted with a polish rod, and a nylon straightening sleeve 107 is provided in the casing a108 above and below the flexible polymer composite spherical particles 110. In the embodiment, the circular particles have fluidity, and under the constant external force pressure, when the particles close to a polished rod are worn and consumed, other particles can continuously flow under the pressure to supplement vacancies, so that long-term sealing is achieved, and experiments show that the flexible particles can be flexibly sealed for more than 10 months. However, since the gas pressure inside the air bag 109 changes significantly with the change of the outside temperature, the flexible sealing of the flexible polymer composite spherical particles 110 to the polish rod is affected, in order to keep the air pressure inside the air bag 109 constant, in this embodiment, a liquid inlet pipe 105 is communicated with the lower part of the air bag 109, the other end of the liquid inlet pipe 105 is connected with a hydraulic cylinder 104, a piston 102 is arranged inside the hydraulic cylinder 104, the liquid inside the cylinder is pressed into the liquid inlet pipe 105 through the piston 102, and a liquid inlet check valve 106 is connected in series on the liquid inlet pipe 105; when the temperature is reduced from high along with the change of seasons or weather, the air pressure in the air bag 109 is reduced along with the reduction of the temperature, when the pressure sensor 103 detects that the pressure value of the air bag 109 is smaller than a set value, the controller sends a command to start the motor 101, the motor 101 pushes the piston 102 to move downwards to squeeze the liquid in the hydraulic cylinder 104 into the air bag 109 to supplement the air pressure in the air bag 109, when the pressure sensor 103 detects that the pressure value of the air bag 109 is larger than the set value, the controller sends a command to stop pressing the motor 101, and the air bag 109 finishes supplementing the pressure. The upper part of the air bag 109 is communicated with an air escape pipe 111, and the air escape pipe 111 is connected with a pressure relief one-way valve 112 in series; when the outside temperature rises from low, the pressure of the air bag 109 is increased, and when the pressure is greater than a set value, the pressure relief one-way valve 112 is automatically opened to keep the pressure in the air bag 109 not exceeding the set value all the time.

As shown in fig. 3 and 4, the blowout preventer 2 of the present embodiment includes a housing B201, a sealing gate plate a202, and a sealing gate plate B205, two vertical sealing partition plates 213 arranged in parallel are connected in the housing B201 in a sealing manner, the two sealing partition plates 213 divide an inner cavity of the housing B201 into three chambers, the sealing gate plate a202 and the sealing gate plate B205 are both located in the chamber in the middle, the approaching surfaces of the sealing gate plate a202 and the sealing gate plate B205 are both provided with arc gaps, and both ends of the arc gaps of the sealing gate plate a202 and the sealing gate plate B205 are both provided with overlapping edges. Two half sealed flashboards of traditional blowout preventer 2 need lean on with the polished rod to lean on sealed again and need two sealed flashboards between lean on sealedly, like this at the in-process of propulsion sealed flashboard, if a sealed face supports and leans on to target in place, then it makes another sealed face also to support and lean on to target in place to hardly advance the flashboard, consequently, there is not tight problem of sealing, different with 2 structures of traditional blowout preventer, this embodiment two half sealed flashboards only need support with the polished rod and lean on to target in place, do not need two sealed flashboards to butt, there is the overlap joint part two sealed flashboards, the overlap joint part is pushing up tightly through knock pin 207, realize the sealing of overlap joint face, consequently, this embodiment has fully guaranteed that the well sealing is reliable, well head oil spilling when avoiding changing compound spherical granule of flexible macromolecule 110.

As shown in fig. 4, two sides of each of the two sealing partition plates 213 are provided with long holes for communicating the middle chamber with the chambers on the two sides, two guide plates 210 are fixedly connected to the side surface of each sealing gate plate, the guide plates 210 extend into the chambers on the two sides through the long holes, the two guide plates 210 in each side chamber are simultaneously screwed with a stud 211 with opposite screwing directions, one end of the stud 211 extends out of the casing B201 and is rotationally sealed with the casing B201, the end portion of the stud 211 extending out of the casing B201 is fixedly connected with a driven runner 212, the casing B201 is provided with a driving runner 204, and the driving runner 204 is meshed with the driven runner 212. When the well is sealed, only the driving rotating wheel 204 needs to be adjusted, the two stud bolts 211 can synchronously rotate, and then the two sealing flashboards synchronously move in opposite directions.

The shaft cross-section of sealed flashboard be the L type, two sealed flashboards shape is the same and be central symmetry, during the shut-in, constitute a cuboid behind two sealed flashboards overlap joint.

As shown in fig. 3, in order to realize rapid sealing of the overlapping surfaces of the two sealing gate plates, the upper end and the lower end of the casing at the overlapping position of the two sealing gate plates after being fastened are respectively fixedly connected with a short sleeve 203, a top pin 207 is respectively inserted into the short sleeve 203 in a sliding and sealing manner, the lower end of the top pin 207 is respectively fixedly connected with an inclined block 206, the upper inclined block 206 on the upper side abuts against the upper end surface of the sealing gate plate B205 through an inclined surface, and the lower inclined block 206 on the lower side abuts against the lower end surface of the sealing gate plate a202 through an inclined surface; when seal gate A202 slides toward the polish rod, under the action of the ramp, ramp block 206 exerts an upward force on it; when the sealing gate B205 slides towards the polish rod, the sloping block 206 exerts a downward force on the polish rod under the action of the sloping surface, so that the overlapping surface of the sealing gate is sealed after the well is sealed.

An adjusting nut 209 is connected to one end of the short sleeve 203 far away from the sealing flashboard in a threaded mode, and a compression spring 208 is arranged between the lower end of the adjusting nut 209 and the ejector pin 207. The adjustment nut 209 is screwed to adjust the elastic pressure of the top pin 207 and the inclined block 206 against the seal shutter, thereby adjusting the sealing degree of the overlapping surface.

The conventional blowout preventer 3 comprises a housing C301, a blowout preventer seat 308 is arranged in the housing C301, the blowout preventer seat 308 is provided with a central hole for a polished rod to pass through, the lower end of the blowout preventer seat 308 is hinged with a blowout preventer cover 310, a powerful torsion spring is arranged on the hinged shaft, and the blowout preventer cover 310 covers the blowout preventer seat 308 under the action of the torsion spring so as to play a blowout preventing role. Unlike the conventional blowout preventer 3: the blowout prevention seat 308 is provided with an axial hole, a trigger pin 306 is arranged in the hole in a sliding mode, the end, far away from the polished rod, of the axial hole is connected with a plug 304 in a threaded mode, a trigger spring 305 is arranged between the plug 304 and the trigger pin 306, the trigger pin 306 tends to slide towards the center of the blowout prevention seat 308 under the action of the trigger spring 305, one end, far away from the polished rod, of the trigger pin 306 is provided with a clamping block 303 with a protrusion, the blowout prevention cover 310 is connected with a stretching rope 309, the other end of the stretching rope 309 is connected with a butting block 302 with a recess, the butting block 302 leans against the shell C301, and the protrusion of the clamping block 303 is clamped in the recess of the butting block 302, so that the butting block 302 is limited to move. The invention designs a triggering structure, when the polished rod normally works, the abutting block 302 leans against the shell C301, the bulge of the clamping block 303 is clamped at the concave position of the abutting block 302, so that the movement of the abutting block 302 is limited, the abutting block 302 pulls open the blowout-preventing cover 310 through the guy wire 309, the blowout-preventing cover 310 is ensured not to be contacted with the polished rod, however, after the polished rod is broken, the triggering pin 306 slides to the center of the blowout-preventing seat 308 under the action of the triggering spring 305, the limitation of the abutting block 302 by the clamping block 303 is instantly released, the blowout-preventing cover 310 is instantly closed under the action of the torsion spring, and the effect of well closing and blowout releasing is achieved. Compared with the existing blowout preventer 3, the invention not only ensures the closing speed of the blowout preventer 310, but also thoroughly avoids the problem of friction between the blowout preventer 310 and a polish rod, and thoroughly solves the problem of friction damage.

For ease of installation, the trigger pin 306 has an annular groove, and the blowout preventer 308 has an axial limit bayonet 307, the limit bayonet 307 being inserted into the annular groove to limit the trigger pin 306. After the polish rod is installed, the limit insert rod 307 is pulled out.

In order to realize automatic adjustment of the pressure in the air bag 109, the present embodiment further includes a controller, a pressure sensor 103 is disposed between the housing a108 and the air bag 109, the piston rod of the piston 102 is controlled by the motor 101 to move, the present embodiment further includes a solar panel and a storage battery, the solar panel absorbs solar energy and converts the solar energy into electric energy to be stored in the storage battery, the storage battery supplies power to the motor 101, the output end of the pressure sensor 103 is connected with the input end of the controller, and the output end of the controller is connected with the motor 101.

Claims

1. The utility model provides a multistage sealing device of beam-pumping unit well head polymer composite particle, includes seal box (1), blowout preventer (2), following inclined to one side follower (4) and preventer (3), and four connect gradually from top to bottom and become an organic whole, its characterized in that: the sealing box (1) comprises a shell A (108), an annular air bag (109) and flexible polymer composite spherical particles (110), wherein the air bag (109) is positioned in the shell A (108), the flexible polymer composite spherical particles (110) are filled in the inner side of a circular ring of the air bag (109), the upper part of the air bag (109) is communicated with an air release pipe (111), the lower part of the air bag (109) is communicated with a liquid inlet pipe (105), a pressure release one-way valve (112) is connected on the air release pipe (111) in series, the other end of the liquid inlet pipe (105) is connected with a hydraulic cylinder (104), a piston (102) is arranged in the hydraulic cylinder (104), liquid in the cylinder is pressed into the liquid inlet pipe (105) through the piston (102), and a liquid inlet one-way valve (106) is connected on the liquid inlet pipe (105) in series; the blowout preventer (2) comprises a shell B (201), a sealing flashboard A (202) and a sealing flashboard B (205), wherein two vertical sealing partition boards (213) which are arranged in parallel are connected in the shell B (201) in a sealing manner, the inner cavity of the shell B (201) is divided into three chambers by the two sealing partition boards (213), the sealing flashboard A (202) and the sealing flashboard B (205) are both positioned in the middle chamber, the close surfaces of the sealing flashboard A (202) and the sealing flashboard B (205) are respectively provided with an arc-shaped gap, both ends of the arc-shaped gap of the sealing flashboard A (202) and the sealing flashboard B (205) are respectively provided with overlapping edges, both sides of the two sealing partition boards (213) are respectively provided with a long hole for communicating the middle chamber and two side chambers, the side surface of each sealing flashboard is respectively and fixedly connected with two guide plates (210), the guide plates (210) respectively extend into the chambers on both sides through the long holes, the two guide plates (210) in each side chamber are simultaneously and are in screwed connection with a double-headed stud (211) with opposite screwing directions, the end part of the stud (211) extending out of the shell B (201) is fixedly connected with a driven rotating wheel (212), the shell B (201) is provided with a driving rotating wheel (204), the driving rotating wheel (204) is meshed with the driven rotating wheel (212), the upper end and the lower end of the shell B (201) at the joint of the two sealed flashboards after being buckled are fixedly connected with a short sleeve (203) respectively, a jacking pin (207) is inserted in the short sleeve (203) in a sliding sealing and inserting mode respectively, the lower end of the jacking pin (207) is fixedly connected with an inclined block (206) respectively, the upper inclined block (206) on the upper side is abutted against the upper end face of the sealed flashboard B (205) through an inclined plane, the lower inclined block (206) on the lower side is abutted against the lower end face of the sealed flashboard A (202) through an inclined plane, one end of the short sleeve (203) far away from the sealed flashboard is in threaded connection with an adjusting nut (209), and a compression spring (208) is arranged between the lower end of the jacking pin (207).

2. The multistage sealing device of polymer composite particles for the wellhead of the oil pumping unit according to claim 1, characterized in that: the blowout preventer (3) comprises a shell C (301), a blowout preventing seat (308) is arranged in the shell C (301), the blowout preventing seat (308) is provided with a central hole for a polished rod to pass through, the lower end of the blowout preventing seat (308) is hinged with a blowout preventing cover (310), a powerful torsion spring is arranged on a hinged shaft, the blowout preventing cover (310) covers the blowout preventing seat (308) under the action of the torsion spring so as to play a blowout preventing role, the blowout preventing seat (308) is provided with an axial hole, a trigger pin (306) is arranged in the hole in a sliding mode, the end, far away from the polished rod, of the axial hole is connected with a plug (304) in a threaded mode, a trigger spring (305) is arranged between the plug (304) and the trigger pin (306), the trigger pin (306) has a tendency of sliding towards the center of the blowout preventing seat (308) under the action of the trigger spring (305), one end, far away from the polished rod, of the trigger pin (306) is provided with a clamping block (303) with a bulge, the anti-blowout preventing cover (310) is connected with a guy rope (309), the other end of the stretching rope (309) is connected with a pressing block (302) with a recess, the pressing block (302) leans against the shell C (301), and the protrusion of the clamping block (303) is clamped at the recess of the pressing block (302), so that the movement of the pressing block (302) is limited.

3. The multistage sealing device of polymer composite particles for the wellhead of the pumping unit according to claim 2, characterized in that: the trigger pin (306) is provided with an annular groove, the blowout preventer (308) is provided with an axial limiting inserted rod (307), and the limiting inserted rod (307) is inserted into the annular groove so as to limit the trigger pin (306).

4. The multistage sealing device of polymer composite particles for the wellhead of the oil pumping unit according to claim 1, characterized in that: the air bag type piston air-conditioning system is characterized by further comprising a controller, a pressure sensor (103) is arranged between the shell A (108) and the air bag (109), the piston rod of the piston (102) is controlled to move through the motor (101), the output end of the pressure sensor (103) is connected with the input end of the controller, and the output end of the controller is connected with the motor (101).

5. The multistage sealing device of polymer composite particles for the wellhead of the pumping unit according to claim 1, characterized in that: the number of the sealing boxes (1) is not less than two, and the two sealing boxes (1) are located above the blowout preventer (2).