CN212272121U - Negative pressure plug removal device and negative pressure plug removal tubular column - Google Patents

Abstract

The utility model relates to a stifled tubular column is separated to negative pressure unblock device and negative pressure, wherein, the negative pressure is separated stifled device and is included the center tube, go up the takeover, take over and the tail pipe down, and the lower part of center tube downwards forms the ladder pipe that an external diameter enlarges, goes up the lower part of takeover and is tubulose and the upper portion outside setting that encircles the center tube at an interval, and this interval forms annular space, and the cover is equipped with in proper order on the ladder pipe and sits and seal sheath and packing element mechanism. A piston pipe is sleeved in the annular space at the upper part of the central pipe, a convex ring with a reduced diameter is formed downwards on the inner wall of the lower part of the tail pipe, a sealing ball is positioned in the tail pipe, and a plurality of centralizing ribs extending along the axis of the tail pipe are formed on the inner wall of the upper part of the tail pipe. The utility model discloses can produce strong negative pressure pumping to along with water hammer vibration effect, strengthen greatly and separate stifled effect, and simple structure can not cause secondary pollution to the stratum.

Description

Negative pressure plug removal device and negative pressure plug removal tubular column

Technical Field

The utility model relates to an oil field removes stifled technical field, especially relates to a stifled tubular column is removed to negative pressure unblock device and negative pressure.

Background

In the development process of an oil field mainly based on water injection development, an oil layer is inevitably blocked by impurities, pipe column corrosion and falling objects and the like in injected water in the injection process, and particularly in a near-wellbore area, the injection pressure of a water well is increased, the injection amount does not reach the standard and the like due to the blockage often occur, so that the water injection development effect is influenced. At present, a plurality of common blockage removal modes of the oil field comprise acidification blockage removal, ultrasonic blockage removal and the like. The acidizing blockage removal method has the best effect, but is easy to generate secondary pollution to the stratum, and meanwhile, a large-scale vehicle set is required to be matched for construction, so that the cost is higher, the operation period is long, meanwhile, the method is not universal, and the method needs to use a corresponding chemical method for stratum pollution caused by different pollutants, so that great difficulty is brought to construction and medicine selection; the ultrasonic blockage removal technology has a good effect on ground tests, and the effect is not obvious in the actual field application process.

Negative pressure unblocking is also a common unblocking means. The most common method is to generate negative pressure through liquid jet, and the principle is to form high-speed jet through a nozzle by high-pressure working water so as to generate negative pressure around the nozzle. This negative pressure device has certain not enough: firstly, the device structure is complicated, has a plurality of cavities, when guaranteeing sealing performance, can lead to holistic wearability not good to because this method can only produce the negative pressure, and can't produce compound mechanical effect such as accompanying water hammer vibration, consequently, the unblock effect is relatively poor.

Therefore, the inventor provides a negative pressure blockage relieving device and a negative pressure blockage relieving pipe column by virtue of experience and practice of related industries for many years, so as to overcome the defects in the prior art.

SUMMERY OF THE UTILITY MODEL

An object of the utility model is to provide a stifled tubular column is separated to negative pressure unblock device and negative pressure can produce strong negative pressure swabbing to along with the water hammer vibration effect, strengthen greatly and separate stifled effect, and simple structure can not cause secondary pollution to the stratum.

The purpose of the utility model can be realized by adopting the following technical scheme:

the utility model provides a negative pressure blockage relieving device, which comprises a central tube, an upper connecting tube, a lower connecting tube and a tail tube which are vertically arranged, wherein the lower part of the central tube downwards forms a stepped tube with an expanded outer diameter; the upper part of the upper connecting pipe is fixed at the upper end of the central pipe, the lower part of the upper connecting pipe is tubular and is arranged around the outer side of the upper part of the central pipe at intervals, the intervals form an annular space, and the middle part of the lower connecting pipe is sleeved and fixed at the outer side of the lower end of the stepped pipe; a setting sheath and a rubber cylinder mechanism are sequentially sleeved on the stepped pipe in the vertical direction between the lower end of the upper connecting pipe and the upper end of the lower connecting pipe, the upper end of the setting sheath extends to the inner side of the lower end of the upper connecting pipe, a non-return ring is arranged between the inner wall of the middle part of the setting sheath and the outer wall of the upper part of the stepped pipe, the non-return ring is fixed with the setting sheath, the inner side of the non-return ring can be axially sleeved on the stepped pipe in a downward unidirectional movement manner, and the lower part of the setting sheath is connected with the stepped pipe through a shearing pin;

a piston pipe is sleeved on the upper part of the central pipe and positioned in the annular space and divides the annular space into an upper annular space and a lower annular space, the lower end of the piston pipe abuts against the upper end surface of the setting sheath, and a plurality of liquid inlet holes communicated with the upper annular space are formed in the circumferential direction of the side wall of the upper part of the central pipe; the tail pipe is arranged at the lower end of the lower connecting pipe, a convex ring with a reduced diameter is formed downwards on the inner wall of the lower part of the tail pipe, a sealing ball is arranged in the tail pipe and above the convex ring, a plurality of centralizing ribs extending along the axis of the centralizing ribs are formed on the inner wall of the upper part of the tail pipe, the centralizing ribs are arranged at intervals along the circumferential direction of the tail pipe, and the diameter of an inscribed circle formed by the inner walls of the centralizing ribs is larger than that of the sealing ball.

The utility model discloses an in the preferred embodiment, every inner wall of righting the muscle is the cambered surface, and the diameter of the circular through-hole that the inner wall of a plurality of muscle of righting enclosed is greater than the diameter of ball sealer.

In a preferred embodiment of the present invention, the diameter of the circular through hole is larger than the diameter of the sealing ball by 4-6 mm.

In a preferred embodiment of the present invention, the top surface of each centering rib is formed with an inclined surface inclined upward from the inner cavity of the tail pipe to the outer wall of the tail pipe, and the top surface of the protruding ring is a conical surface gradually expanding upward.

The utility model discloses an among the preferred embodiment, set up annular groove at the middle part inner wall of setting the sheath, the stopping ring cover is established in annular groove, is equipped with vertical incision on the lateral wall of stopping ring, encircles the locking tooth that is equipped with many zigzags along its circumference at the internal face of stopping ring, is equipped with many tooth sockets that match with the locking tooth at ladder pipe upper portion outer wall, and the locking tooth can block to be established in the tooth socket that corresponds.

In a preferred embodiment of the present invention, the central tube includes an inner central tube, an outer central tube and a connecting sleeve, the outer central tube is sleeved on the outer side of the lower portion of the inner central tube at intervals, and the lower end of the inner central tube and the lower end of the outer central tube are fixedly connected through the connecting sleeve; the outer central tube forms the stepped tube, and the liquid inlet hole is formed in the side wall of the upper portion of the central tube.

The utility model discloses an among the preferred embodiment, go up the takeover and become knot and cylinder liner including top connection, joint, the upper end of center tube including fixed is established to the inboard cover of lower extreme of top connection, and the lower extreme outside of top connection becomes to detain fixed connection through the joint with the upper end of cylinder liner is inboard, forms foretell annular space between the lower part inner wall of cylinder liner and the upper end outer wall of interior center tube, and it is inboard that the upper end of setting the sheath extends to the lower extreme of cylinder liner.

In a preferred embodiment of the present invention, the setting sheath comprises a stop sleeve and a setting piston sleeve which are arranged up and down, and the setting piston sleeve is connected with the outer central tube through a shearing pin; the upper end of the backstop sleeve extends to the inner side of the lower end of the cylinder sleeve, a stepped hole with an enlarged diameter is formed downwards on the inner wall of the lower end of the backstop sleeve, and the annular groove is formed between the upper shaft shoulder of the stepped hole and the upper end face of the setting piston sleeve.

In a preferred embodiment of the present invention, the lower end inner wall of the upper joint is in threaded connection with the upper end outer wall of the inner central tube, the lower end outer wall of the upper joint is in threaded connection with the inner wall of the joint buckle, the outer wall of the joint buckle is in threaded connection with the upper end inner wall of the cylinder sleeve, the lower end outer wall of the inner central tube is in threaded connection with the inner wall of the connecting sleeve, the outer wall of the connecting sleeve is in threaded connection with the lower end inner wall of the outer central tube, the lower end outer wall of the outer central tube is in threaded connection with the middle inner wall of the lower connecting tube, and an annular sealing ring; and annular sealing rings are respectively arranged between the inner wall of the piston pipe and the outer wall of the upper part of the inner central pipe as well as between the outer wall of the piston pipe and the inner wall of the cylinder sleeve.

The utility model discloses an in a preferred embodiment, packing element mechanism includes that a plurality of covers establish the packing element on outer center tube, presss from both sides between two adjacent packing elements and establishes a fender ring.

The utility model also provides a stifled tubular column is separated to negative pressure, include from last plug valve, the pipe that oils and foretell negative pressure that connects extremely down in proper order and separate stifled device.

The utility model discloses an in the preferred embodiment, still be equipped with between last oil pipe and the stifled device of negative pressure unblock and be the bleeder and the lower oil pipe that set up from top to bottom.

From the above, the negative pressure blockage removing device of the utility model can make the rubber sleeve mechanism set by pressing, and then the device can generate a strong negative pressure pumping effect on the oil layer when moving upwards, so as to pump the oil layer dirt in the near wellbore area into the wellbore; the device can generate water hammer vibration effect during downward movement to generate certain acting force on the stratum so as to enhance the blockage removing effect, and further can realize the effects of removing dirt, removing scales and removing blockage of the area close to the well by repeated pumping of the up-and-down reciprocating motion of the device and water hammer vibration, thereby greatly improving the blockage removing effect and generating no secondary pollution on the stratum. Simultaneously, through setting up a plurality of muscle of rightting, can play the effect of direction rightting to the ball sealer, can the centering when guaranteeing the ball sealer downstream, especially when being applied to highly deviated well, can avoid causing the problem that the tail pipe bottom can't close completely because of the ball sealer skew is not placed in the middle, and then guarantee that device upward movement in-process tail pipe bottom seals all the time and closes, guarantees that the device can normally clear up stifled operation. The whole device has simple structure, simple and convenient operation and low cost.

Drawings

The drawings are only intended to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

FIG. 1: does the utility model provides a negative pressure unblocks device's schematic structure diagram.

FIG. 2: is a cross-sectional view taken along the line a-a in fig. 1.

FIG. 3: does the utility model provides a structure schematic diagram of stifled tubular column is separated to negative pressure.

The reference numbers illustrate:

100. a negative pressure unblocking device;

1. a central tube; 11. an inner center tube; 111. a liquid inlet hole; 12. an outer center tube; 13. connecting sleeves;

2. an upper connecting pipe; 21. an upper joint; 22. changing the joint; 23. a cylinder liner;

3. setting the sheath; 31. a withdrawal stopping sleeve; 311. an annular groove; 32. setting a piston sleeve; 321. shearing the pin;

4. a rubber cylinder mechanism; 41. a rubber cylinder; 42. a baffle ring;

5. a lower connecting pipe;

6. a piston tube;

7. a tail pipe; 71. a convex ring; 72. righting the rib;

8. a sealing ball;

200. a plug valve;

300. feeding an oil pipe;

400. an oil drain device;

500. discharging an oil pipe;

600. a sleeve.

Detailed Description

In order to clearly understand the technical features, objects, and effects of the present invention, embodiments of the present invention will be described with reference to the accompanying drawings.

As shown in fig. 1 and 2, the present embodiment provides a negative pressure unblocking apparatus 100, which includes a central pipe 1, an upper connection pipe 2, a lower connection pipe 5, and a tail pipe 7, which are vertically disposed.

Wherein, the lower part of center tube 1 forms the ladder pipe that an external diameter enlarges downwards, goes up the upper portion of taking over 2 and fixes the upper end at center tube 1, goes up the lower part of taking over 2 and is tubulose and set up around the upper portion outside of center tube 1 with interval, and this interval forms annular space, and the lower extreme outside at the ladder pipe is fixed in the middle part cover of taking over 5 down. The upper and lower direction of being located between 2 lower extremes of upper pipe and the lower pipe 5 upper ends of lower connecting pipe on the ladder pipe is equipped with in proper order and sits and seals sheath 3 and packing element mechanism 4, the upper end of sitting and sealing sheath 3 extends to the lower extreme inboard of upper pipe 2, it is equipped with a retaining ring (not shown in the figure) to sit between the middle part inner wall of sheath 3 and the ladder pipe upper portion outer wall, retaining ring and sitting and sealing sheath 3 are fixed, the inboard of retaining ring can be the axial and establish on the ladder pipe with one-way displacement ground cover down, the lower part of sitting and sealing sheath 3 is passed through shearing pin 321 and is connected with the ladder pipe.

On the upper portion of center tube 1 and be located the annular space endotheca and establish a piston pipe 6 to annular space cuts apart into annular space and annular space down, and the lower extreme of piston pipe 6 supports and leans on the up end of setting sheath 3, sets up a plurality ofly and the feed liquor hole 111 of last annular space intercommunication in the upper portion lateral wall circumference of center tube 1. The tail pipe 7 is arranged at the lower end of the lower connecting pipe 5, a convex ring 71 with a reduced diameter is formed downwards on the inner wall of the lower part of the tail pipe 7, the sealing ball 8 is positioned in the tail pipe 7 and above the convex ring 71, a plurality of centralizing ribs 72 extending along the axis of the centralizing ribs are formed on the inner wall of the upper part of the tail pipe 7, the centralizing ribs 72 are arranged at intervals along the circumferential direction of the tail pipe 7, and the diameter of an inscribed circle formed by the inner walls of the centralizing ribs 72 is larger than the diameter of the sealing ball 8.

Specifically, the upper end of the piston tube 6 is generally tubular and disposed around the outer side of the upper end of the inner center tube 11 at a space, and the space constitutes the above-mentioned upper annular space. When the device is used, the negative pressure blocking removing device 100 is placed in a well along with a pipe column at a specified position, water is injected into the central pipe 1 to be pressurized, liquid enters the upper annular space through the liquid inlet hole 111, the liquid pushes the piston pipe 6 to move downwards, the piston pipe 6 pushes the setting sheath 3 downwards, after the shearing pin 321 is sheared by hydraulic pressure, the piston pipe 6 pushes the setting sheath 3 to continue to move downwards, the rubber barrel extruding mechanism 4 is extruded to expand, and setting is completed. After being seated, the common rubber cylinder mechanism 4 is spaced from the inner wall of the sleeve 600 by 8-10 mm so as to facilitate the up-and-down movement of the negative pressure blockage removing device 100. The arrangement of the retaining ring can ensure that the rubber cylinder mechanism 4 is always in a pressing state.

Then the negative pressure block removing device 100 reciprocates up and down along with the pipe column, when the negative pressure block removing device 100 moves upwards, the sealing ball 8 blocks the bottom of the tail pipe 7 under the action of the gravity of liquid in the pipe column, and the pipe column generates a strong negative pressure pumping action on an oil layer in the ascending process, so that dirt of the oil layer in a near-well zone is pumped into a shaft. When the negative pressure blockage relieving device 100 moves downwards, strong impact action is generated between the bottom of the negative pressure blockage relieving device 100 and liquid, the physical action of water hammer vibration is generated, certain acting force is generated on the stratum, and blockage relieving is facilitated.

Meanwhile, liquid enters from the bottom of the tail pipe 7 and has a thrust force on the sealing ball 8, when the thrust force reaches a certain value, the sealing ball 8 is jacked open, the sealing ball 8 moves upwards, and the bottom of the tail pipe 7 is opened; at this time, dirt in the shaft enters the inner cavity of the central tube 1 together with liquid, and then is lifted to a pollution tank through the upper tubular column. When the negative pressure deblocking device 100 moves upwards again, the gravity of the liquid in the pipe column generates downward thrust on the sealing ball 8 to push the sealing ball 8 to move downwards to block the bottom of the tail pipe 7; then the oil layer continues to generate the pumping action of negative pressure. The up-and-down reciprocating motion can realize the blockage removing effect, and the water injection pressure is obviously reduced after normal construction.

In addition, when the device is applied to a deviated well or even a highly deviated well (generally, when the included angle between the axis of the well shaft and the vertical direction is more than 5 degrees, the deviated well is called as a deviated well, and when the included angle is more than 30 degrees, the deviated well is called as a highly deviated well), and the sealing ball 8 is attached to the side wall of the lower side of the pipe column under the action of gravity and cannot be centered in the downward movement process of the pipe column, so that the sealing ball 8 cannot completely seal the bottom end of the tail pipe 7, and the operation is influenced. In this embodiment, the plurality of centering ribs 72 are formed on the inner wall of the tail pipe 7, so that the movement space of the sealing ball 8 can be limited to a certain extent, and the sealing ball 8 can be guided and centered to prevent the sealing ball 8 from shifting.

Therefore, the negative pressure block removal device 100 in this embodiment can set the rubber sleeve mechanism 4 by pressing, and then the device can generate a pumping effect of strong negative pressure on an oil layer when moving upwards, so as to pump dirt of the oil layer in the near wellbore zone into the wellbore; the device can generate water hammer vibration effect during downward movement to generate certain acting force on the stratum so as to enhance the blockage removing effect, and further can realize the effects of removing dirt, removing scales and removing blockage of the area close to the well by repeated pumping of the up-and-down reciprocating motion of the device and water hammer vibration, thereby greatly improving the blockage removing effect and generating no secondary pollution on the stratum. Meanwhile, the sealing ball 8 can be guided and centered by arranging the plurality of centering ribs 72, the problem that the bottom end of the tail pipe 7 cannot be completely closed due to the fact that the sealing ball 8 is not centered when the sealing ball 8 moves downwards is solved, especially when the sealing ball is applied to a highly-deviated well, the bottom of the tail pipe 7 is always sealed and closed in the upward movement process of the device, and the device can normally perform blockage removing operation. The whole device has simple structure, simple and convenient operation and low cost.

In a specific implementation manner, generally, the inner wall of each of the centering ribs 72 is an arc surface, and the diameter of the circular through hole surrounded by the inner walls of the plurality of centering ribs 72 is larger than the diameter of the sealing ball 8.

In order to ensure the righting guide effect of the righting rib 72 on the sealing ball 8 and avoid sand jamming caused by too small gap between the righting rib and the sealing ball 8, the diameter of the circular through hole is larger than the diameter of the sealing ball 8 by 4-6 mm, namely the gap between the sealing ball 8 and the inner wall of the righting rib 72 is 2-3 mm. The number of the centering ribs 72 is determined according to actual needs, and for example, three centering ribs 72 are provided in the present embodiment.

In order to facilitate the smooth descending of the sealing ball 8, the top surface of each centering rib 72 is formed with an inclined surface which is inclined upwards from the inner cavity of the tail pipe 7 to the outer wall of the tail pipe 7. In order to ensure the sealing effect between the sealing ball 8 and the convex ring 71, the top surface of the convex ring 71 is a tapered surface which is gradually enlarged upwards.

In practical application, an annular groove 311 is formed in the inner wall of the middle of the setting sheath 3, the anti-return ring is sleeved in the annular groove 311, a longitudinal notch is formed in the side wall of the anti-return ring, a plurality of zigzag locking teeth are annularly arranged on the inner wall surface of the anti-return ring along the circumferential direction of the anti-return ring, a plurality of tooth grooves matched with the locking teeth are formed in the outer wall surface of the upper portion of the stepped pipe, and the locking teeth can be clamped in the corresponding tooth grooves.

Therefore, the anti-return ring and the stepped pipe have the function of moving in one direction and not returning back, so that the setting sheath 3 cannot move back after moving downwards, and the rubber cylinder mechanism 4 is ensured to be always in a pressing state. Of course, the anti-retraction ring may also adopt other structural forms as long as it can ensure that the setting sheath 3 does not retract after moving down, and this embodiment is only an example.

Further, for convenience of processing and installation, the central tube 1 includes an inner central tube 11, an outer central tube 12 and a connecting sleeve 13, the outer central tube 12 is disposed at an interval outside the lower portion of the inner central tube 11, and the lower end of the inner central tube 11 and the lower end of the outer central tube 12 are fixedly connected through the connecting sleeve 13. The outer central tube 12 forms the stepped tube, the liquid inlet hole 111 is formed in the upper side wall of the central tube 1, and the tooth socket is formed in the upper side wall of the outer central tube 12. Wherein, the outer central tube 12 and the inner central tube 11 are sleeved at intervals, so that the material and the cost can be saved.

The upper connecting pipe 2 comprises an upper joint 21, a joint buckle 22 and a cylinder sleeve 23, the inner side of the lower end of the upper joint 21 is fixedly sleeved on the upper end of the inner central pipe 11, the outer side of the lower end of the upper joint 21 is fixedly connected with the inner side of the upper end of the cylinder sleeve 23 through the joint buckle 22, the inner wall of the lower part of the cylinder sleeve 23 and the outer wall of the upper end of the inner central pipe 11 form the annular space, and the upper end of the setting sheath 3 extends to the inner side of the lower end of the cylinder sleeve 23. The upper end of the piston tube 6 generally abuts against the lower end face of the coupling buckle 22.

The setting jacket 3 includes a stopping sleeve 31 and a setting piston sleeve 32 which are vertically arranged, and the setting piston sleeve 32 is connected with the outer central tube 12 through a shearing pin 321. The upper end of the retaining sleeve 31 extends to the inner side of the lower end of the cylinder sleeve 23, the inner wall of the lower end of the retaining sleeve 31 is downward formed with a stepped hole with an enlarged diameter, and the annular groove 311 is formed between the upper shaft shoulder of the stepped hole and the upper end surface of the setting piston sleeve 32.

Specifically, an annular groove is further formed in the upper outer wall of the outer center tube 12, a through hole is formed in the side wall of the setting piston sleeve 32, and the shearing pin 321 is inserted into the through hole and the groove. When the central tube 1 is pressurized, the liquid pushes the piston tube 6 to move downwards, the piston tube 6 sequentially pushes the stopping sleeve 31 and the setting piston sleeve 32, and after the shearing pin 321 is sheared by the pushing force, the piston tube 6 continues to push the stopping sleeve 31 and the setting piston sleeve 32 to move downwards, so that the rubber cylinder mechanism 4 is extruded.

Further, in order to facilitate installation, the sealing of the inner cavity of the central tube 1 and the upper annular space is ensured simultaneously, the lower end inner wall of the upper joint 21 is in threaded connection with the upper end outer wall of the inner central tube 11, the lower end outer wall of the upper joint 21 is in threaded connection with the inner wall of the joint buckle 22, the outer wall of the joint buckle 22 is in threaded connection with the upper end inner wall of the cylinder sleeve 23, the lower end outer wall of the inner central tube 11 is in threaded connection with the inner wall of the connecting sleeve 13, the outer wall of the connecting sleeve 13 is in threaded connection with the lower end inner wall of the outer central tube 12, the lower end outer wall of the outer central tube 12 is in threaded connection with the middle inner wall. Annular sealing rings are respectively arranged between the inner wall of the piston pipe 6 and the upper outer wall of the inner central pipe 11 and between the outer wall of the piston pipe 6 and the inner wall of the cylinder sleeve 23.

In the actual use process, in order to ensure that the packing element mechanism 4 can be normally set, the packing element mechanism 4 includes a plurality of packing elements 41 sleeved on the outer central tube 12, and a retaining ring 42 is clamped between two adjacent packing elements 41, thereby avoiding the condition that the process length of a single packing element 41 causes S-shaped bending. The number of the glue cartridges 41 is determined as needed, and for example, three glue cartridges 41 are provided in total in the present embodiment.

In addition, in a possible implementation manner, in order to save materials and cost, the upper end of the lower connecting pipe 5 is disposed around the outer side of the lower end of the outer central pipe 12 in a tubular shape at intervals, and then a stop ring 42 is required to be interposed between the lowermost rubber cylinder 41 and the upper end of the lower connecting pipe 5 to ensure that the rubber cylinder 41 is normally expanded.

As shown in fig. 3, the present embodiment further provides a negative pressure deblocking pipe string, which comprises a plug valve 200, an upper oil pipe 300 and the negative pressure deblocking device 100, which are sequentially connected from top to bottom.

In the initial state, the plug valve 200 is in the open state. When the device works, after the whole pipe column is controlled to be lowered into a designed position by an operating machine, the valve of the sleeve 600 is closed, the plug valve 200 is kept in an open state, and the pump truck is pressed to expand and set the rubber cylinder mechanism 4 of the negative pressure blocking removal device 100. Then keeping the plug valve 200 open, connecting the upper end of the pipe column with a hose line to a pollution tank, driving the pipe column to reciprocate up and down by using an operating machine, and generating a negative pressure pumping effect on an oil layer when the pipe column moves upwards so as to pump dirt of the oil layer into a shaft; when the pipe column moves downwards, the physical action of water hammer vibration is generated, and dirt in the shaft enters the pipe column along with liquid and is lifted to a pollution tank. The up-and-down reciprocating motion realizes the blockage removing function.

Wherein, plug valve 200 here mainly plays prevents the effect of spouting, in the course of the work, if the blowout phenomenon appears, in time closes plug valve 200 to guarantee construction safety.

In practical application, an oil drain 400 and an oil drain pipe 500 which are vertically arranged are further arranged between the oil supply pipe 300 and the negative pressure blockage relieving device 100.

After the plug removal operation is completed, the plug valve 200 is firstly removed, and then the oil drainer 400 is opened by throwing a rod into the pipe column so as to discharge the liquid in the pipe column, so that the clean production is realized and the construction safety is ensured. And finally, the tubular column is lifted out, and normal oil extraction operation at the wellhead can be carried out.

The above description is only exemplary of the present invention, and is not intended to limit the scope of the present invention. Any person skilled in the art should also realize that such equivalent changes and modifications can be made without departing from the spirit and principles of the present invention.

Claims (12)

1. A negative pressure blockage removing device is characterized by comprising a central pipe, an upper connecting pipe, a lower connecting pipe and a tail pipe which are vertically arranged, wherein the lower part of the central pipe downwards forms a stepped pipe with an expanded outer diameter;

the upper part of the upper connecting pipe is fixed at the upper end of the central pipe, the lower part of the upper connecting pipe is tubular and is arranged around the outer side of the upper part of the central pipe at intervals, the intervals form an annular space, and the middle part of the lower connecting pipe is sleeved and fixed at the outer side of the lower end of the stepped pipe; a setting sheath and a rubber cylinder mechanism are sequentially sleeved on the stepped pipe in the vertical direction between the lower end of the upper connecting pipe and the upper end of the lower connecting pipe, the upper end of the setting sheath extends to the inner side of the lower end of the upper connecting pipe, a non-return ring is arranged between the inner wall of the middle part of the setting sheath and the outer wall of the upper part of the stepped pipe, the non-return ring is fixed with the setting sheath, the inner side of the non-return ring can be axially sleeved on the stepped pipe in a downward unidirectional movement manner, and the lower part of the setting sheath is connected with the stepped pipe through a shearing pin;

a piston pipe is sleeved on the upper part of the central pipe and positioned in the annular space and divides the annular space into an upper annular space and a lower annular space, the lower end of the piston pipe abuts against the upper end surface of the setting sheath, and a plurality of liquid inlet holes communicated with the upper annular space are formed in the circumferential direction of the side wall of the upper part of the central pipe;

the tail pipe is arranged at the lower end of the lower connecting pipe, a convex ring with a reduced diameter is formed downwards on the inner wall of the lower part of the tail pipe, a sealing ball is arranged in the tail pipe and above the convex ring, a plurality of centralizing ribs extending along the axis of the centralizing ribs are formed on the inner wall of the upper part of the tail pipe, the centralizing ribs are arranged at intervals along the circumferential direction of the tail pipe, and the diameter of an inscribed circle formed by the inner walls of the centralizing ribs is larger than that of the sealing ball.

2. The negative pressure deblocking device of claim 1,

the inner wall of each righting rib is an arc surface, and the diameter of a circular through hole formed by the inner walls of the righting ribs is larger than that of the sealing ball.

3. The negative pressure deblocking device of claim 2,

the diameter of the circular through hole is 4-6 mm larger than that of the sealing ball.

4. The negative pressure deblocking device of claim 1,

the top surface of each righting rib is provided with an inclined surface which is inclined upwards from the inner cavity of the tail pipe to the outer wall of the tail pipe, and the top surface of the convex ring is a conical surface which is gradually enlarged upwards.

5. The negative pressure deblocking device of claim 1,

the inner wall of the middle part of the setting sheath is provided with an annular groove, the anti-backing ring is sleeved in the annular groove, the side wall of the anti-backing ring is provided with a longitudinal notch, the inner wall surface of the anti-backing ring is provided with a plurality of zigzag locking teeth along the circumferential direction, the outer wall surface of the upper part of the stepped pipe is provided with a plurality of tooth grooves matched with the locking teeth, and the locking teeth can be clamped in the corresponding tooth grooves.

6. The negative pressure deblocking device of claim 5,

the central tube comprises an inner central tube, an outer central tube and a connecting sleeve, the outer central tube is sleeved on the outer side of the lower part of the inner central tube at intervals, and the lower end of the inner central tube is fixedly connected with the lower end of the outer central tube through the connecting sleeve; the outer central tube forms the stepped tube, and the liquid inlet hole is arranged on the side wall of the upper part of the central tube.

7. The negative pressure deblocking device of claim 6,

the upper connecting pipe comprises an upper joint, a joint buckle and a cylinder sleeve, the upper end of the inner central pipe is fixedly sleeved on the inner side of the lower end of the upper joint, the outer side of the lower end of the upper joint is fixedly connected with the inner side of the upper end of the cylinder sleeve through the joint buckle, an annular space is formed between the inner wall of the lower portion of the cylinder sleeve and the outer wall of the upper end of the inner central pipe, and the upper end of the setting protective sleeve extends to the inner side of the lower end of the cylinder sleeve.

8. The negative pressure deblocking device of claim 7,

the setting protective sleeve comprises a stop sleeve and a setting piston sleeve which are arranged up and down, and the setting piston sleeve is connected with the outer central tube through a shearing pin; the upper end of the backstop sleeve extends to the inner side of the lower end of the cylinder sleeve, a stepped hole with an enlarged diameter is formed downwards on the inner wall of the lower end of the backstop sleeve, and the annular groove is formed between the upper shaft shoulder of the stepped hole and the upper end face of the setting piston sleeve.

9. The negative pressure deblocking device of claim 7,

the inner wall of the lower end of the upper joint is in threaded connection with the outer wall of the upper end of the inner central tube, the outer wall of the lower end of the upper joint is in threaded connection with the inner wall of the joint change buckle, the outer wall of the joint change buckle is in threaded connection with the inner wall of the upper end of the cylinder sleeve, the outer wall of the lower end of the inner central tube is in threaded connection with the inner wall of the connecting sleeve, the outer wall of the connecting sleeve is in threaded connection with the inner wall of the lower end of the outer central tube, the outer wall of the lower end of the outer central tube is in; and annular sealing rings are respectively arranged between the inner wall of the piston pipe and the outer wall of the upper part of the inner central pipe as well as between the outer wall of the piston pipe and the inner wall of the cylinder sleeve.

10. The negative pressure deblocking device of claim 6,

the rubber tube mechanism comprises a plurality of rubber tubes sleeved on the outer central tube, and a retaining ring is clamped between every two adjacent rubber tubes.

11. A negative pressure plug removal pipe column, which is characterized by comprising a plug valve, an upper oil pipe and the negative pressure plug removal device according to any one of claims 1 to 10, which are sequentially connected from top to bottom.

12. The negative pressure unplugging string of claim 11,

an oil drainer and a lower oil pipe which are arranged up and down are also arranged between the upper oil pipe and the negative pressure blockage relieving device.

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