CN114542440A

CN114542440A - Self-draining oil pump

Info

Publication number: CN114542440A
Application number: CN202011338128.0A
Authority: CN
Inventors: 罗恩勇; 郎宝山; 蒋明; 吴非; 柳盛森; 蒋川; 张乾赐; 刘冬雷; 狄强; 王书慧
Original assignee: Petrochina Co Ltd
Current assignee: Petrochina Co Ltd
Priority date: 2020-11-25
Filing date: 2020-11-25
Publication date: 2022-05-27
Anticipated expiration: 2040-11-25
Also published as: CN114542440B

Abstract

The invention relates to a self-oil-drainage oil well pump which comprises a pump cylinder and a plunger, wherein the plunger can be arranged in the pump cylinder in a vertically sliding manner, the top of the plunger is connected with a downward-placing pipe column, the bottom of the plunger is provided with a first ball valve which is communicated upwards in a one-way manner, a second ball valve which is communicated upwards in a one-way manner is arranged in the pump cylinder and is positioned below the first ball valve, the top of the second ball valve is fixedly provided with a first ejector rod, and the top of the second ball valve is provided with a second ejector rod in a vertically movable manner; the first ball valve moves downwards along with the plunger until the top end of the first ejector rod is abutted against the bottom of a first valve ball in the first ball valve so as to push the first valve ball to move upwards until the first ball valve is opened; and the top end of the second ejector rod is abutted against the bottom of the first ball valve, and the second ejector rod is pushed to move downwards to the bottom end of the second ejector rod to be abutted against the top edge of a second valve ball in the second ball valve, so that the second valve ball is pushed to deviate to one side to open the second ball valve. The invention solves the technical problems of great control difficulty and poor oil drainage effect of the underground oil drainer.

Description

Self-draining oil pump

Technical Field

The invention relates to the technical field of oil extraction engineering, in particular to an oil-well pump capable of automatically draining oil.

Background

With the continuous expansion of the scale of fireflooding and SAGD (steam assisted gravity drainage), the outer diameter of an oil well pump is continuously increased in order to improve the lifting displacement of the oil well. However, the problem also occurs, that is, in order to ensure the reliability of the oil well pump during operation, the oil drain is not usually installed in the oil well of the large-diameter oil well pump, so that finally, when the pipe string is lifted, the liquid in the oil pipe is unscrewed at the coupling along with the connection with the oil pipe, the liquid in the oil pipe splashes outwards, which is very unfavorable for the safety of oil well operation and environment, and meanwhile, an operator needs to operate at the well mouth, so that the health of the operator is very unfavorable. At present, although various underground oil drains aiming at large-diameter oil-well pumps exist, the underground oil drains are difficult to adapt to underground complex environments, the control difficulty is high, and misoperation (namely, opening in advance or not opening when opening is needed) often occurs.

Aiming at the problems that the related technology underground oil drainer is large in control difficulty and poor in oil drainage effect, an effective solution is not provided at present.

Therefore, the inventor provides the self-oil-drainage oil well pump by virtue of experience and practice of related industries for many years so as to overcome the defects in the prior art.

Disclosure of Invention

The invention aims to provide a self-oil-drainage oil well pump, which can put down a plunger after oil pumping operation is finished, and control a ball valve in a pump cylinder to be automatically opened through the plunger, so that residual oil in a pipe column is discharged out of a shaft, thereby achieving the purpose of oil drainage, being simple to operate and thorough in oil drainage, ensuring the safety of pipe column lifting operation and avoiding environmental pollution.

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

the invention provides a self-draining oil well pump which is arranged at the bottom of a sucker rod and is driven into a preset position in a shaft along with the sucker rod, wherein the self-draining oil well pump comprises a pump cylinder and a plunger, the pump cylinder and the plunger are both vertically arranged and are of cylindrical structures with two open ends, the plunger can be arranged in the pump cylinder in a vertically sliding manner, the top of the plunger is connected with a lowering pipe column, the bottom of the plunger is provided with a first ball valve which is communicated upwards in a one-way manner, the interior of the pump cylinder is arranged below the first ball valve and is provided with a second ball valve which is communicated upwards in a one-way manner, the top of the second ball valve is fixedly provided with a first ejector rod, and the top of the second ball valve is provided with a second ejector rod which can move upwards and downwards;

the first ball valve moves downwards along with the plunger until the top end of the first ejector rod is abutted against the bottom of a first valve ball in the first ball valve so as to push the first valve ball to move upwards to open the first ball valve; and the top end of the second ejector rod is abutted against the bottom of the first ball valve, and the second ejector rod is pushed to move downwards to the bottom end of the second ejector rod to be abutted against the top edge of a second valve ball in the second ball valve, so that the second valve ball is pushed to deviate to one side to open the second ball valve.

In a preferred embodiment of the present invention, the self-draining oil-well pump further includes a third ball valve that is communicated in one direction upwards, and the third ball valve is disposed on the top of the plunger;

first gaps are reserved among the outer wall of the plunger, the outer wall of the first ball valve, the outer wall of the third ball valve and the inner wall of the pump barrel, so that a liquid passing channel for communicating the upper portion of the third ball valve with the lower portion of the first ball valve is formed.

In a preferred embodiment of the present invention, the first ball valve includes a first valve housing, a first ball seat, and the first ball valve, the first valve housing is a vertically arranged cylindrical structure with two open ends, the first ball seat is an annular structure, a top of the first valve housing is connected to a bottom of the plunger, the first ball seat is arranged in the first valve housing, a limiting plate is arranged in the first valve housing above the first ball seat to partition between the limiting plate and the first ball seat to form a first chamber, a first liquid passing hole communicated with the first chamber is formed in the limiting plate, the first ball valve is movably arranged in the first chamber, and a seat seal is formed between the first ball valve and the first ball seat.

In a preferred embodiment of the present invention, the first ball valve further includes a compression ring, the compression ring is a vertically arranged cylindrical structure with two open ends, the compression ring is arranged at the bottom of the first valve cover, and the top of the compression ring abuts against the bottom of the first ball seat.

In a preferred embodiment of the present invention, the second ball valve includes a second valve housing, a second ball seat, and the second valve ball, the second valve housing is a vertically arranged cylindrical structure with a sealed top and an open bottom, the second ball seat is an annular structure, the top of the second valve housing is connected to the bottom of the pump barrel, the second ball seat is disposed in the second valve housing to form a second chamber by partitioning between the top of the second valve housing and the second ball seat, the top of the second valve housing is provided with a second liquid passing hole communicated with the second chamber, the second valve ball is movably disposed in the second chamber, and a seating seal is formed between the second valve ball and the second ball seat.

In a preferred embodiment of the present invention, the self-draining oil well pump further includes a lower joint, the lower joint is a vertically arranged cylindrical structure with two open ends, the lower joint is arranged at the bottom of the second valve housing, and the top of the lower joint abuts against the bottom of the second ball seat.

In a preferred embodiment of the present invention, the first push rod is vertically disposed above the second valve housing, a bottom of the first push rod is connected to a top of the second valve housing, and a top of the first push rod can extend into the first ball valve from below the first ball valve and abut against the bottom of the first ball valve.

In a preferred embodiment of the present invention, an installation sleeve is disposed on one side of the top of the second valve housing, which is located on the first ejector rod, the installation sleeve is a cylindrical structure which is vertically disposed and has two open ends, the bottom of the second ejector rod penetrates through the installation sleeve and extends into the second chamber, a pressing cap is disposed on the top of the second ejector rod, a spring which pushes the second ejector rod to move upwards for resetting is sleeved on the second ejector rod, and two ends of the spring are respectively abutted to the bottom of the pressing cap and the top of the installation sleeve.

In a preferred embodiment of the present invention, a pin is disposed on an outer wall of the second ejector rod, an annular first boss and an annular second boss are respectively disposed on an inner wall of the mounting sleeve along a circumferential direction of the mounting sleeve, the first boss is located above the second boss, and the pin is slidably embedded between a bottom of the first boss and a top of the second boss;

the bottom of the first boss and the top of the second boss are respectively and continuously provided with a plurality of first zigzag limiting grooves and a plurality of second zigzag limiting grooves along the circumferential direction of the mounting sleeve, each first limiting groove and each second limiting groove are vertically staggered, and a second gap is reserved between each first limiting groove and the adjacent second limiting groove, so that the pin can slide between the first limiting groove and the second limiting groove through the second gap.

In a preferred embodiment of the present invention, an inner wall of the first position-limiting groove extends vertically, and another opposite inner wall of the first position-limiting groove extends obliquely; one inner wall of the second limiting groove extends vertically, the other opposite inner wall of the second limiting groove extends obliquely, and the inclination direction of the inner wall in the first limiting groove is opposite to that of the inner wall in the second limiting groove.

In a preferred embodiment of the present invention, the bottom of each two adjacent second limiting grooves is respectively provided with a first extending groove and a second extending groove which are communicated with the corresponding second limiting groove, and the first extending groove and the second extending groove both extend in a direction away from the first limiting groove;

the length of the first extending groove is greater than the distance that the first ball valve moves downwards to abut against the first valve ball and the first ejector rod, and the length of the first extending groove is less than the distance that the second ejector rod moves downwards to abut against the second valve ball;

the length of the second extending groove is larger than the distance of the second ejector rod moving downwards to abut against the second valve ball.

In a preferred embodiment of the present invention, the third ball valve includes a third valve housing, a third valve ball, and a third ball seat, the third valve housing is vertically arranged and has a cylindrical structure with two open ends, the third ball seat is an annular structure, the third ball seat is arranged in the third valve housing, the third valve ball is movably arranged in the third valve housing and located above the third ball seat, and a seat is formed between the third valve ball and the third ball seat.

In a preferred embodiment of the present invention, a ball joint is connected between the third ball valve and the top of the plunger, the ball joint has a vertically arranged cylindrical structure with two open ends, and the top of the ball joint abuts against the bottom of the third ball seat.

In a preferred embodiment of the invention the top of the third bonnet is connected to the bottom of the lowering string.

In a preferred embodiment of the present invention, an upper joint is disposed at the top of the pump cylinder, the upper joint is a vertically disposed cylindrical structure with two open ends, the bottom of the upper joint is connected to the top of the pump cylinder, and the top of the upper joint is connected to the bottom of the sucker rod.

From the above, the self-draining oil pump of the invention has the characteristics and advantages that: a plunger capable of sliding up and down is arranged in the pump barrel, a first ball valve which is communicated in a one-way upwards is arranged at the bottom of the plunger, a second ball valve which is communicated in a one-way upwards is arranged below the first ball valve, the top of the second ball valve is provided with a fixed first mandril and a second mandril which can move up and down, and by lowering the plunger, the first ball valve can be driven to move downwards, the first push rod pushes the first ball valve to move upwards until the first ball valve is opened, and the second push rod pushes the second ball valve to deflect to one side until the second ball valve is opened, thereby can make the surplus fluid in pump barrel and the sucker rod that is located first ball valve top release to the pit shaft through first ball valve and second ball valve in proper order, reach the purpose of automatic draining, easy operation, the draining is thorough, avoids surplus fluid to splash outwards, has improved the security of playing the tubular column operation greatly, prevents the pollution to the environment and to the harm that operating personnel is healthy.

Drawings

The drawings are only for purposes of illustrating and explaining the present invention and are not to be construed as limiting the scope of the present invention.

Wherein:

FIG. 1: is a structural schematic diagram of the self-draining oil well pump.

FIG. 2: which is a partial enlargement of the position a in fig. 1.

FIG. 3: which is a partial enlarged view of the position B in fig. 1.

FIG. 4 is a schematic view of: a partial enlarged view of the position C in fig. 1.

FIG. 5: a partial enlarged view of the position D in fig. 4.

FIG. 6: the invention is a schematic diagram of the position relationship between a first boss, a second boss and a pin in the self-draining oil well pump.

The reference numbers in the invention are:

1. a pump barrel; 2. A first ball valve;

201. a first valve cover; 2011. A limiting plate;

2012. a first liquid passing hole; 2013. A first chamber;

202. a first valve ball; 203. A first ball seat;

204. a compression ring; 3. A plunger;

4. a pin; 5. A second ball valve;

501. a second valve cover; 5011. A second liquid passing hole;

5012. a second chamber; 502. A second valve ball;

503. a second ball seat; 6. A third ball valve;

601. a third valve cover; 602. A third valve ball;

603. a third ball seat; 7. A ball seat joint;

8. an upper joint; 9. A lower joint;

10. a liquid passing channel; 11. A second ejector rod;

12. installing a sleeve; 1201. A first boss;

1202. a second boss; 1203. A first limit groove;

1204. a second limit groove; 1205. A first extension groove;

1206. a second extension groove; 13. Pressing the cap;

14. a spring; 15. A first ejector rod;

16. a second gap.

Detailed Description

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

As shown in fig. 1 to 6, the present invention provides a self-draining oil pump, which is disposed at the bottom of a sucker rod and is lowered to a predetermined position in a well bore along with the sucker rod. The self-draining oil well pump comprises a pump cylinder 1 and a plunger 3, wherein the pump cylinder 1 and the plunger 3 are both of cylindrical structures which are arranged along the vertical direction and have two open ends, the plunger 3 can be arranged in the pump cylinder 1 in a vertically sliding manner (namely along the axial direction of the pump cylinder 1), the top of the plunger 3 is connected with a lowering pipe column, the bottom of the plunger 3 is provided with a first ball valve 2 which is communicated upwards in a one-way manner, the inside of the pump cylinder 1 is positioned below the first ball valve 2 and is provided with a second ball valve 5 which is communicated upwards in a one-way manner, the top of the second ball valve 5 is fixedly provided with a first ejector rod 15, and the top of the second ball valve 5 is provided with a second ejector rod 11 which can move upwards and downwards; the top of the plunger 3 is connected with a lowering pipe column, the plunger 3 is driven by the lowering pipe column to move downwards, the first ball valve 2 synchronously moves downwards along with the plunger 3 until the top end of the first ejector rod 15 is abutted against the bottom of the first valve ball 202 in the first ball valve 2, and the first valve ball 202 is pushed to move upwards until the first ball valve 2 is opened; and the top end of the second ejector rod 11 is abutted against the bottom of the first ball valve 2, and the second ejector rod 11 is pushed to move downwards to the bottom end of the second ejector rod 11 to be abutted against the top edge of a second valve ball 502 in the second ball valve 5, so that the second valve ball 502 is pushed to deviate towards one side until the second ball valve 5 is opened, and then the oil drainage operation can be completed.

The invention is provided with a plunger 3 which can slide up and down in a pump cylinder 1, a first ball valve 2 which is communicated upwards in a one-way is arranged at the bottom of the plunger 3, a second ball valve 5 which is communicated upwards in a one-way is arranged below the first ball valve 2, a fixed first ejector rod 15 and a second ejector rod 11 which can move up and down are arranged at the top of the second ball valve 5, the first ball valve 2 can be driven to move downwards by lowering the plunger 3, and then the first ejector rod 15 pushes a first valve ball 202 to move upwards until the first ball valve 2 is opened, and simultaneously the second ejector rod 11 pushes a second valve ball 502 to deviate to one side until the second ball valve 5 is opened, thereby the pump cylinder 1 above the first ball valve 2 and the residual oil in a sucker rod are discharged into a shaft through the first ball valve 2 and the second ball valve 5 in sequence, the purpose of automatic oil drainage is achieved, the operation of the whole oil drainage process is simple, the oil drainage is thorough, the residual oil is prevented from splashing outwards, the safety of the operation of the pipe string is greatly improved, and the pollution to the environment and the harm to the health of operators are prevented.

In an alternative embodiment of the present invention, as shown in fig. 1 and 2, an upper joint 8 is provided at the top of the pump barrel 1, the upper joint 8 is a cylindrical structure provided along the vertical direction and having two open ends, the inner wall of the bottom of the upper joint 8 is in threaded connection with the outer wall of the top of the pump barrel 1, and the inner wall of the top of the upper joint 8 is in threaded connection with the outer wall of the bottom of the sucker rod, so as to facilitate the disassembly and assembly of the pump barrel 1, and is suitable for field operation.

In an alternative embodiment of the present invention, as shown in fig. 1 and 2, the self-draining oil well pump further includes a third ball valve 6 which is communicated in a one-way manner upwards, and the third ball valve 6 is arranged at the top of the plunger 3; first gaps are reserved among the outer wall of the plunger 3, the outer wall of the first ball valve 2, the outer wall of the third ball valve 6 and the inner wall of the pump barrel 1, so that a liquid passing channel 10 communicating the upper portion of the third ball valve 6 with the lower portion of the first ball valve 2 is formed. After the first ball valve 2 and the second ball valve 5 are synchronously opened, only the residual oil in the plunger 3 between the third ball valve 6 and the first ball valve 2 is discharged into the shaft through the first ball valve 2 and the second ball valve 5 in sequence, and the residual oil in the pump cylinder 1 above the third ball valve 6 and in the sucker rod flows to the lower part of the first ball valve 2 through the liquid passage 10 and is discharged into the shaft through the second ball valve 5, so that the oil drainage operation of the oil well pump is completed.

Specifically, as shown in fig. 1 and 2, the third ball valve 6 includes a third valve housing 601, a third ball 602, and a third ball seat 603, the third valve housing 601 is a cylindrical structure that is vertically disposed and has openings at both ends, the third ball seat 603 is an annular structure that is coaxially disposed with the third valve housing 601, the third ball seat 603 is fixedly disposed in the third valve housing 601, the third ball 602 is movably disposed in the third valve housing 601 above the third ball seat 603, and a bottom outer wall of the third ball 602 abuts against an annular inner edge at the top of the third ball seat 603, so that a seat seal is formed between the third ball 602 and the third ball seat 603.

Further, the outer wall of the bottom of the lowering pipe column is connected with the inner wall of the top of the third valve cover 601 through threads.

Further, as shown in fig. 1 and 2, a ball seat joint 7 is connected between the top of the third ball valve 6 and the plunger 3, the ball seat joint 7 is of a cylindrical structure with two open ends and is arranged along the vertical direction, the top outer wall of the ball seat joint 7 is connected with the bottom inner wall of the third valve housing 601 through threads, the bottom outer wall of the ball seat joint 7 is connected with the top outer wall of the plunger 3 through threads, the top of the ball seat joint 7 is abutted against the bottom of the third ball seat 603, the third ball seat 603 is fixed through the ball seat joint 7, and the installation stability of the third ball seat 603 is guaranteed.

Specifically, as shown in fig. 1 and 3, the first ball valve 2 includes a first valve housing 201, a first ball seat 203 and a first ball 202, the first valve housing 201 is a cylindrical structure which is arranged along a vertical direction and has two open ends, the first ball seat 203 is an annular structure which is arranged coaxially with the first valve housing 201, a top outer wall of the first valve housing 201 is connected with a bottom inner wall of the plunger 3 by a thread, the first ball seat 203 is fixedly arranged in the first valve housing 201, and a limit plate 2011 is arranged above the first ball seat 203 in the first valve housing 201, a first chamber 2013 is formed between the limiting plate 2011 and the first ball seat 203 in a separated mode, the limiting plate 2011 is provided with a plurality of first liquid passing holes 2012 communicated with the first chamber 2013, the first valve ball 202 can be movably arranged in the first chamber 2013, and the outer wall of the bottom of the first valve ball 202 is abutted against the annular inner edge of the top of the first ball seat 203, so that a seat seal is formed between the first valve ball 202 and the first ball seat 203.

Further, as shown in fig. 1 and fig. 3, the first ball valve 2 further includes a compression ring 204, the compression ring 204 is a cylindrical structure which is vertically arranged and has two open ends, the compression ring 204 is arranged at the bottom of the first valve housing 201, the upper outer wall of the compression ring 204 is in threaded connection with the inner wall of the bottom of the first valve housing 201, and the top of the compression ring 204 is abutted against the bottom of the first ball seat 203, so that the first ball seat 203 is fixed through the compression ring 204, and the stability of installation of the first ball seat 203 is ensured.

Specifically, as shown in fig. 1 and 4, the second ball valve 5 includes a second valve housing 501, a second ball seat 503 and a second valve ball 502, the second valve housing 501 is a cylindrical structure with a top sealed and a bottom open along the vertical direction, the second ball seat 503 is an annular structure coaxially arranged with the second valve housing 501, the top outer wall of the second valve housing 501 is connected with the bottom inner wall of the pump barrel 1 by a screw thread, the second ball seat 503 is fixedly arranged in the second valve housing 501, a second chamber 5012 is formed between the top of the second valve housing 501 and the second ball seat 503 in a partitioned manner, a plurality of second liquid passing holes 5011 communicated with the second chamber 5012 are formed in the top of the second valve housing 501, the second valve ball 502 is movably arranged in the second chamber 5012, and the outer wall of the bottom of the second valve ball 502 abuts against the inner annular edge of the top of the second ball seat 503, so that a seat seal is formed between the second valve ball 502 and the second ball seat 503.

Further, as shown in fig. 1 and 4, the self-draining oil well pump further comprises a lower joint 9, the lower joint 9 is arranged along the vertical direction and has a cylindrical structure with two open ends, the lower joint 9 is arranged at the bottom of the second valve housing 501, the top outer wall of the lower joint 9 is in threaded connection with the bottom inner wall of the second valve housing 501, the top of the lower joint 9 is abutted against the bottom of the second ball seat 503, the second ball seat 503 can be fixed through the lower joint 9, the installation stability of the second ball seat 503 is ensured, and an internal thread is further arranged on the inner wall of the lower joint 9, so that other functional pipe columns can be connected conveniently.

Further, as shown in fig. 1, 4, and 5, the first push rod 15 is disposed above the second valve housing 501 in the vertical direction, the bottom of the first push rod 15 is connected with the middle position of the top of the second valve housing 501 through threads, during the downward movement of the first ball valve 2, the top of the first push rod 15 can extend into the first ball valve 2 from below the first ball valve 2 and abut against the bottom of the first valve ball 202, so as to push the first valve ball 202 open, the first ball valve 2 is opened, and the remaining oil between the first ball valve 2 and the third ball valve 6 is sequentially discharged into the wellbore through the first ball valve 2 and the second ball valve 5.

In an alternative embodiment of the present invention, as shown in fig. 1, 4, and 5, a mounting sleeve 12 is disposed on a side of the top of the second valve housing 501, which is located on the first plunger 15, the mounting sleeve 12 is connected to the second valve housing 501 through a screw thread, the mounting sleeve 12 is a cylindrical structure that is disposed along a vertical direction and has two open ends, the second plunger 11 is disposed along the vertical direction, the bottom of the second plunger 11 passes through the mounting sleeve 12 and extends into the second chamber 5012, the top of the second plunger 11 is located above the mounting sleeve 12, a pressing cap 13 is fixedly arranged at the top of the second ejector rod 11, a spring 14 is sleeved on the second ejector rod 11, one end of the spring 14 is abutted against the bottom of the pressing cap 13, the other end of the spring 14 is abutted against the top of the mounting sleeve 12, in the downward movement state of the second lift pin 11, the second lift pin 11 can be pushed upward by the elastic force of the spring 14 to return to the original position.

In an alternative embodiment of the present invention, as shown in fig. 1, 4 to 6, a pin 4 is fixedly disposed on an outer wall of the second ejector 11, an annular first boss 1201 and an annular second boss 1202 are respectively disposed on an inner wall of the mounting sleeve 12 along a circumferential direction of the mounting sleeve 12, the first boss 1201 is located above the second boss 1202, and the pin 4 is slidably embedded between a bottom of the first boss 1201 and a top of the second boss 1202; a plurality of zigzag first limiting grooves 1203 are continuously arranged at the bottom of the first boss 1201 along the circumferential direction of the mounting sleeve 12, one inner wall of each first limiting groove 1203 extends vertically, and the other opposite inner wall of each first limiting groove 1203 extends obliquely; a plurality of second zigzag limiting grooves 1204 are continuously formed in the top of the second boss 1202 along the circumferential direction of the mounting sleeve 12, one inner wall of each second limiting groove 1204 extends vertically, the other opposite inner wall of each second limiting groove 1204 extends obliquely, the inclination direction of the inner wall of each first limiting groove 1203 is opposite to that of the inner wall of each second limiting groove 1204, each first limiting groove 1203 and each second limiting groove 1204 are staggered in the vertical direction, and a second gap 16 is reserved between each first limiting groove 1203 and two adjacent second limiting grooves 1204 of the first limiting groove 1203, so that the pin 4 can slide between the first limiting groove 1203 and the second limiting grooves 1204 through the second gap 16. The upward movement and downward movement of the pin 4 can be limited through the first limiting groove 1203 and the second limiting groove 1204, so that the downward movement distance of the second ejector rod 11 is limited, and the second ejector rod 11 can be restored to the original height in the upward movement process.

Further, as shown in fig. 6, the bottom of each of the two adjacent second limiting grooves 1204 is provided with a first extending groove 1205 and a second extending groove 1206 which are communicated with the corresponding second limiting groove 1204, and the first extending groove 1205 and the second extending groove 1206 both extend in a direction away from the first limiting groove 1203; the length of the first extension slot 1205 is greater than the distance that the first ball valve 2 moves downwards to abut against the first valve ball 202 and the first push rod 15, the length of the first extension slot 1205 is less than the distance that the second push rod 11 moves downwards to abut against the second valve ball 502, and the length of the second extension slot 1206 is greater than the distance that the second push rod 11 moves downwards to abut against the second valve ball 502. When the oil well pump is installed, the pin 4 can be assembled in the first limit groove 1203 in advance, and the first limit groove 1203 is opposed to the inclined inner wall of the second limit groove 1204 communicating with the first extension groove 1205 in the vertical direction, after being lowered to a predetermined position in the wellbore, and pressed from the surface, the first ball valve 2 may push the pin 4 downward into the first extension slot 1205, the downward moving distance of the second push rod 11 is limited by the first extending slot 1205, the length of the first extending slot 1205 can ensure that the first push rod 15 pushes the first valve ball 202 upwards, and the second push rod 11 and the second valve ball 502 are not contacted, in this state, the first ball valve 2 is opened, the second ball valve 5 is still in the closed state, the state is maintained for a certain time, if the pressure in the pump barrel 1 and the sucker rod is unchanged, the sealing performance of the pipe column can be determined to be good, and the leakage detection operation of the pipe column is completed. Then, the ground is not pressed, the second mandril 11 moves upwards under the action of the elastic force of the spring 14, and the pin 4 enters another first limit groove 1203 adjacent to the original first limit groove 1203 in the process of moving upwards due to the guiding action of the inclined inner wall of the first limit groove 1203. When carrying out the draining operation, promote plunger 3 to move down through transferring the tubular column, first ball valve 2 can promote second ejector pin 11 and move down and get into to the second extending groove 1206 in, it is spacing to carry out the distance that moves down of second ejector pin 11 through the second extending groove 1206, the length of second extending groove 1206 can guarantee that first ejector pin 15 upwards pushes away first valve ball 202, second ejector pin 11 promotes second valve ball 502 and takes place the skew simultaneously, then under this state, first ball valve 2 and second ball valve 5 all open, accomplish the draining operation of tubular column promptly.

The using process of the invention is as follows:

assembling: the first ball valve 2, the second ball valve 5 and the third ball valve 6 are installed in the pump barrel 1, the setting pin 4 is located in a first limiting groove 1203, and the first limiting groove 1203 is vertically opposite to the inclined inner wall of a second limiting groove 1204 communicated with the first extending groove 1205 (i.e. the position a in fig. 6).

And (4) leakage checking: the oil well pump is put into a preset position in a shaft along with the sucker rod, the oil well pump is pressed into the pump barrel 1 through the ground, the first ball valve 2, the second ball valve 5 and the third ball valve 6 are all in a closed state, pressure liquid pushes the plunger 3 and the first ball valve 2 to move downwards, the first ball valve 2 pushes the second ejector rod 11 to move downwards, the pin 4 on the second ejector rod 11 stops moving downwards after moving downwards to the bottom position (namely, the position b in the figure 6) of the first extension groove 1205, and then the downward movement distance of the second ejector rod 11 is limited through the first extension groove 1205, at the moment, the first ejector rod 15 can push the first valve ball 202 upwards and open, the second ejector rod 11 and the second valve ball 502 are not in contact, the state is kept for a certain time, if the ground pressure is stable and does not fall, the sealing performance of the pipe column is good, and normal operation can be realized; if the pressure is reduced, the initial position of the pin 4 may be installed in a misplaced manner (that is, the pin is installed at the position c in fig. 6), so that the second valve ball 502 is pushed away by the second ejector rod 11, the first ball valve 2 and the second ball valve 5 are both in an open state, and at this time, the pipe column needs to be lifted out to readjust the position of the pin 4, and then the pipe column is lowered into the shaft for continuous testing; if the pressure is reduced during the continuous test, the leakage problem of the pump barrel 1 or the sucker rod is shown, and the pipe column needs to be pulled out for leakage detection and maintenance until the leakage problem is solved.

Oil drainage: when oil drainage needs to be carried out on residual oil in the pipe column, the plunger 3 is lowered, the first ball valve 2 can push the second ejector rod 11 to move downwards to enter the bottom position (namely, the position d in fig. 6) of the second extension groove 1206, at the moment, the first ejector rod 15 pushes the first valve ball 202 upwards and pushes the second valve ball 502 to deflect, the first ball valve 2 and the second ball valve 5 are both opened, and the residual oil between the first ball valve 2 and the third ball valve 6 is discharged into a shaft through the first ball valve 2 and the second ball valve 5 in sequence; and residual oil above the third ball valve 6 is discharged to a shaft through the liquid passing channel 10 and the second ball valve 5 in sequence, so that oil drainage operation of the pipe column is completed.

The self-draining oil pump has the characteristics and advantages that:

one, this can be from draining formula oil-well pump is suppressed through ground, can promote first ball valve 2 and second ball valve 5 completion opening action in the pump barrel 1 respectively through first ejector pin 15 and second ejector pin 11, thereby can make the surplus fluid in pump barrel 1 and the sucker rod release to the pit shaft smoothly in, reach the purpose of automatic draining, whole draining process operation is simple, the draining is thorough, avoid surplus fluid to splash outwards, the security of playing the tubular column operation has been improved greatly, prevent pollution to the environment and the harm to operating personnel health.

Secondly, this can be from draining formula oil-well pump is through the cooperation of first boss 1201, second boss 1202 and pin 4, can go into the pit shaft back under the oil-well pump, tests the leak operation to oil-well pump and sucker rod, carries out oil pumping and draining operation under the good prerequisite of assurance tubular column leakproofness, effectively improves the security and the operating efficiency of operation.

The above description is only an exemplary embodiment of the present invention, and is not intended to limit the scope of the present invention. Any equivalent changes and modifications that can be made by one skilled in the art without departing from the spirit and principles of the invention should fall within the protection scope of the invention.

Claims

1. An oil-well pump capable of draining oil automatically is arranged at the bottom of an oil pumping rod and is lowered to a preset position in a shaft along with the oil pumping rod, it is characterized in that the self-draining oil well pump comprises a pump cylinder (1) and a plunger (3), the pump cylinder (1) and the plunger (3) are both vertically arranged and have cylindrical structures with two open ends, the plunger (3) is arranged in the pump cylinder (1) in a manner of sliding up and down, the top of the plunger (3) is connected with a lowering pipe column, the bottom of the plunger (3) is provided with a first ball valve (2) which is communicated upwards in a one-way, a second ball valve (5) which is communicated upwards in a one-way is arranged in the pump cylinder (1) and is positioned below the first ball valve (2), a first ejector rod (15) is fixedly arranged at the top of the second ball valve (5), a second ejector rod (11) is arranged at the top of the second ball valve (5) in a manner of moving up and down;

the first ball valve (2) moves downwards along with the plunger (3) until the top end of the first ejector rod (15) is abutted against the bottom of a first valve ball (202) in the first ball valve (2) so as to push the first valve ball (202) to move upwards to open the first ball valve (2); and the top end of the second ejector rod (11) is abutted against the bottom of the first ball valve (2), and the second ejector rod (11) is pushed to move downwards to the bottom end of the second ejector rod (11) to be abutted against the top edge of a second valve ball (502) in the second ball valve (5), so that the second valve ball (502) is pushed to deviate to one side until the second ball valve (5) is opened.

2. The self-draining pump according to claim 1, further comprising a third ball valve (6) which is in one-way communication upwards, wherein the third ball valve (6) is arranged on the top of the plunger (3);

first gaps are reserved among the outer wall of the plunger (3), the outer wall of the first ball valve (2), the outer wall of the third ball valve (6) and the inner wall of the pump barrel (1) so as to form a liquid passing channel (10) for communicating the upper part of the third ball valve (6) with the lower part of the first ball valve (2).

3. The oil-well pump capable of draining oil automatically according to claim 2, wherein the first ball valve (2) comprises a first valve cover (201), a first ball seat (203) and the first valve ball (202), the first valve cover (201) is a vertically arranged cylindrical structure with two open ends, the first ball seat (203) is an annular structure, the top of the first valve cover (201) is connected with the bottom of the plunger (3), the first ball seat (203) is arranged in the first valve cover (201), a limiting plate (2011) is arranged in the first valve cover (201) and above the first ball seat (203) so as to form a first chamber (2013) by separating between the limiting plate (2011) and the first ball seat (203), a first liquid passing hole (2012) communicated with the first chamber (2013) is formed in the limiting plate (2011), the first valve ball (202) is movably disposed within the first chamber (2013), a setting being formed between the first valve ball (202) and the first ball seat (203).

4. The self-draining oil well pump according to claim 3, wherein the first ball valve (2) further comprises a compression ring (204), the compression ring (204) is a vertically arranged cylindrical structure with two open ends, the compression ring (204) is arranged at the bottom of the first valve cover (201), and the top of the compression ring (204) is abutted against the bottom of the first ball seat (203).

5. The oil-well pump as claimed in claim 2 or 3, characterized in that the second ball valve (5) comprises a second valve cover (501), a second ball seat (503) and a second valve ball (502), the second valve cover (501) is a vertically arranged cylindrical structure with a closed top and an open bottom, the second ball seat (503) is an annular structure, the top of the second valve cover (501) is connected with the bottom of the pump barrel (1), the second ball seat (503) is arranged in the second valve cover (501) to form a second chamber (5012) by separating between the top of the second valve cover (501) and the second ball seat (503), the top of the second valve cover (501) is provided with a second liquid through hole (5011) communicated with the second chamber (5012), and the second valve ball (502) is movably arranged in the second chamber (5012), a setting is formed between the second valve ball (502) and the second ball seat (503).

6. The self-draining oil well pump according to claim 5, further comprising a lower joint (9), wherein the lower joint (9) is a vertically arranged cylindrical structure with two open ends, the lower joint (9) is arranged at the bottom of the second valve cover (501), and the top of the lower joint (9) is abutted against the bottom of the second ball seat (503).

7. The self-draining oil well pump according to claim 5, wherein the first top rod (15) is vertically arranged above the second valve cover (501), the bottom of the first top rod (15) is connected with the top of the second valve cover (501), and the top of the first top rod (15) can extend into the first ball valve (2) from the lower part of the first ball valve (2) and abut against the bottom of the first ball valve (202).

8. The self-oil-drainage oil well pump as claimed in claim 5, wherein a mounting sleeve (12) is arranged on one side of the first ejector rod (15) at the top of the second valve cover (501), the mounting sleeve (12) is a cylindrical structure which is vertically arranged and has two open ends, the bottom of the second ejector rod (11) penetrates through the mounting sleeve (12) and extends into the second cavity (5012), a pressing cap (13) is arranged at the top of the second ejector rod (11), a spring (14) which pushes the second ejector rod (11) to move upwards and return is sleeved on the second ejector rod (11), and two ends of the spring (14) are respectively abutted to the bottom of the pressing cap (13) and the top of the mounting sleeve (12).

9. The oil-well pump capable of self oil drainage according to claim 8, wherein a pin (4) is arranged on the outer wall of the second ejector rod (11), an annular first boss (1201) and an annular second boss (1202) are respectively arranged on the inner wall of the mounting sleeve (12) along the circumferential direction of the mounting sleeve (12), the first boss (1201) is positioned above the second boss (1202), and the pin (4) is slidably embedded between the bottom of the first boss (1201) and the top of the second boss (1202);

the bottom of the first boss (1201) and the top of the second boss (1202) are respectively and continuously provided with a plurality of serrated first limiting grooves (1203) and a plurality of serrated second limiting grooves (1204) along the circumferential direction of the mounting sleeve (12), each first limiting groove (1203) and each second limiting groove (1204) are vertically staggered, and a second gap (16) is reserved between the first limiting groove (1203) and the adjacent second limiting groove (1204), so that the pin (4) can slide between the first limiting groove (1203) and the second limiting groove (1204) through the second gap (16).

10. The self-draining oil well pump of claim 9, wherein one inner wall of the first limiting groove (1203) extends vertically, and the other opposite inner wall of the first limiting groove (1203) extends obliquely; one inner wall of the second limiting groove (1204) extends vertically, the other opposite inner wall of the second limiting groove (1204) extends obliquely, and the inclination direction of the inner wall in the first limiting groove (1203) is opposite to that of the inner wall in the second limiting groove (1204).

11. The oil-well pump of claim 9, wherein the bottoms of two adjacent second limiting grooves (1204) are respectively provided with a first extending groove (1205) and a second extending groove (1206) which are communicated with the corresponding second limiting groove (1204), and the first extending groove (1205) and the second extending groove (1206) both extend in a direction away from the first limiting groove (1203);

the length of the first extension groove (1205) is greater than the distance that the first ball valve (2) moves downwards to abut against the first valve ball (202) and the first ejector rod (15), and the length of the first extension groove (1205) is less than the distance that the second ejector rod (11) moves downwards to abut against the second valve ball (502);

the length of the second extension groove (1206) is larger than the distance of the second ejector rod (11) moving downwards to abut against the second valve ball (502).

12. The self-draining oil well pump according to claim 2, wherein the third ball valve (6) comprises a third valve housing (601), a third valve ball (602) and a third ball seat (603), the third valve housing (601) is a vertically arranged cylindrical structure with two open ends, the third ball seat (603) is an annular structure, the third ball seat (603) is arranged in the third valve housing (601), the third valve ball (602) is movably arranged in the third valve housing (601) and located above the third ball seat (603), and a seat seal is formed between the third valve ball (602) and the third ball seat (603).

13. The self-draining pump according to claim 12, wherein a ball seat joint (7) is connected between the third ball valve (6) and the top of the plunger (3), the ball seat joint (7) is a vertically arranged cylindrical structure with two open ends, and the top of the ball seat joint (7) is abutted against the bottom of the third ball seat (603).

14. The self-draining pump according to claim 12, wherein the top of the third bonnet (601) is connected to the bottom of the lowering string.

15. The oil-well pump capable of draining oil automatically according to claim 1, characterized in that the top of the pump barrel (1) is provided with an upper joint (8), the upper joint (8) is a vertically arranged cylindrical structure with two open ends, the bottom of the upper joint (8) is connected with the top of the pump barrel (1), and the top of the upper joint (8) is connected with the bottom of the sucker rod.