CN113123950B - A submersible electric plunger pump - Google Patents

Abstract

The invention provides a submersible electric plunger pump, comprising a motor assembly, the motor mover of the motor assembly performs reciprocating linear motion; the first end of the screen tube of the outer cylinder assembly is connected with the motor stator, and the second end of the screen tube is connected to the outer The first end of the barrel structure is connected; the swimming valve assembly of the pump barrel assembly is connected with the second end of the motor mover, and the swimming valve assembly is connected with the first end of the pump barrel structure; the plunger of the plunger assembly The first end of the structure is connected to the fixed valve assembly, and the second end of the plunger structure is connected to the second end of the outer cylinder structure; the pump cylinder assembly is located in the cylinder of the outer cylinder assembly, and the fixed valve assembly and the plunger structure The first end of the pump barrel assembly is located in the barrel of the pump barrel assembly, and the inner diameter of the pump barrel structure is adapted to the outer diameter of the first end of the plunger structure. The technical solution of this embodiment solves the problem of the submersible electric plunger pump in the prior art that the flow area of the electric submersible plunger pump is small without increasing the pump diameter.

Description

A submersible electric plunger pump

technical field

The invention relates to the technical field of oil exploitation equipment, in particular to a submersible electric plunger pump.

Background technique

In recent years, with the increasing demand for oil resources, the mining equipment in the oil mining industry has become more and more diversified in order to adapt to different mining environments and improve mining efficiency.

In the prior art, the oil well pump system is often used for oil lifting. The power unit of the oil well pump system is a pumping unit, which is commonly known as a "kowtow machine". Thereby the oil is continuously lifted and pumped out. However, due to the friction between the sucker rod and the tubing, the sucker rod, tubing, etc. are easy to wear and tear, so it is not suitable for horizontal wells and high-inclination directional wells, and it is impossible to adjust parameters such as the speed that is more convenient to adjust, and the pumping unit is used to output oil. The packing box of the flange at the mouth is prone to oil leakage. In addition, in the prior art, the submersible electric plunger pump has been applied on a certain scale in the oil field as the power device of the oil production system. The submersible electric plunger pump is mainly composed of two major systems: the submersible linear motor system and the oil well pump system. The submersible linear motor system directly converts electrical energy into reciprocating linear motion, and the oil well pump system lifts the bottom hole liquid to the wellhead. In the submersible electric plunger pump, the mover push rod of the submersible linear motor system is directly connected to the plunger of the oil pump system, and the stator of the submersible linear motor system is connected to the pump barrel of the oil well pump system, that is, the submersible linear motor and the pumping system are connected. After the oil pump is connected on the ground, it is lowered into the well with the oil pipe.

Submersible electric plunger pumps are mainly used in thin oil wells, and can also be used in heavy oil wells. Since the downhole liquid is fed through the swimming valve (the valve is reciprocating with the plunger or the pump barrel, the liquid in the pump can be pumped Excluded one-way ball valve) enters, then enters the inner diameter of the plunger, and then enters the pump barrel, because the floating valve has a small flow area, and the frictional resistance between the oil and the flow channel is large, which affects the pump efficiency.

At present, in order to increase the oil lifting efficiency of the submersible electric plunger pump, it is necessary to increase the flow area of the swimming valve in the submersible electric plunger pump, but the current solution is to increase the pump of the submersible electric plunger pump. diameter, and then increase the diameter of the swimming valve. This structural change, on the one hand, increases the outer diameter of the submersible electric plunger pump, making it impossible to run in small casing oil wells; on the other hand, increases the lifting thrust and power of the linear motor of the submersible electric plunger pump , affecting the depth of the submersible electric plunger pump, reducing the scope of application of the submersible electric plunger pump.

Contents of the invention

The main purpose of the present invention is to provide an electric submersible plunger pump to solve the problem that the electric submersible plunger pump in the prior art has a small flow area without increasing the pump diameter. The problem.

In order to achieve the above object, the present invention provides a submersible electric plunger pump, including a motor assembly, the motor assembly includes a motor stator, a motor mover and a cable, the first end of the motor mover is passed through the motor stator, and the cable and The motor stator is electrically connected, and the motor mover performs reciprocating linear motion; it also includes an outer cylinder assembly, which includes a screen tube and an outer tube structure. The first end of the screen tube is connected to the motor stator, and the second end of the screen tube is connected to the outer tube. The first end of the structure is connected; the pump barrel assembly, the pump barrel assembly includes the pump barrel structure and the swimming valve assembly, the first end of the swimming valve assembly is connected with the second end of the motor rotor, and the swimming valve The second end of the assembly is connected with the first end of the pump barrel structure; the plunger assembly, the plunger assembly includes a fixed valve assembly and a plunger structure, the first end of the plunger structure is connected with the fixed valve assembly, and the column The second end of the plug structure is connected with the second end of the outer cylinder structure; the pump cylinder assembly is located in the cylinder of the outer cylinder assembly, the first end of the fixed valve assembly and the plunger structure are located in the cylinder of the pump cylinder assembly, and the pump cylinder The inner diameter of the structure matches the outer diameter of the first end of the plunger structure.

Further, the outer cylinder structure includes a joint and an outer working cylinder, the first end of the outer working cylinder is connected to the second end of the screen pipe, and the second end of the outer working cylinder is connected to the first end of the joint.

Further, the electric submersible plunger pump also includes an oil pipe connected to the second end of the joint.

Further, the plunger structure includes a plunger suspension tube and a plunger sleeve, the first end of the plunger sleeve is connected to the fixed valve assembly, and the second end of the plunger sleeve is connected to the first end of the plunger suspension tube. Connected, the second end of the plunger suspension tube is connected with the joint.

Further, the second end of the plunger suspension tube is connected to the inner wall at the middle position of the joint.

Further, the second end of the pump barrel structure is located between the first end of the plunger suspension barrel and the second end of the plunger suspension barrel, and the second end of the pump barrel structure has an inward flange.

Further, the inner diameter of the pump barrel structure is in clearance fit with the outer diameter of the first end of the plunger structure.

Further, an oil inlet passage is provided on the side of the first end of the movable valve assembly, the plunger structure 42 is a cylindrical structure, and the area of the oil inlet passage is larger than the cross-sectional area of the plunger structure.

Further, the side of the screen pipe has an oil inlet channel for communicating with the inner space of the outer cylinder assembly and the outer space of the outer cylinder assembly.

Further, the submersible electric plunger pump further includes a centralizer, and the centralizer is arranged on the stator of the motor and is located on a side of the stator of the motor away from the rotor of the motor.

Applying the technical solution of the present invention, when using the electric submersible plunger pump to pump oil, the electric submersible plunger pump is lowered into the casing of the oil well, and when the motor component drives the motor mover to perform a downstroke action, the motor mover drives the The pump barrel assembly moves backward. At this time, the fixed valve assembly is closed under the pressure in the oil pipe, and the floating valve assembly is opened under the pressure of the oil layer, and the oil enters the cavity between the pump barrel assembly and the plunger assembly. Inside. When the motor assembly drives the motor mover to do an upstroke, the motor mover drives the pump barrel assembly to move forward, so that the pressure of the oil entering the cavity between the pump barrel assembly and the plunger assembly rises, and the swimming valve assembly is closed. , the oil cannot flow back, and the pressure of the oil in the cavity between the pump barrel assembly and the plunger assembly rises further, the fixed valve assembly is opened, and then the oil passes through the fixed valve assembly and the plunger structure in turn from the submerged The oil is discharged from the electric plunger pump. The up and down strokes of the above-mentioned motor mover, the forward and backward movements are repeated continuously, and the continuous oil pumping and lifting work of the submersible electric plunger pump can be realized, so that the oil at the bottom of the well is lifted to the wellhead through the oil pipe. In addition, by arranging the pump barrel assembly in the barrel of the outer barrel assembly, and then setting the first end of the plunger assembly in the barrel of the pump barrel assembly, this nesting structure makes the diameter of the swimming valve assembly larger than The diameter of the fixed valve assembly, so that the diameter of the floating valve assembly is increased compared with the diameter of the fixed valve assembly, so that the flow area of the floating valve assembly is relatively increased, and the oil lift is increased. Lifting efficiency, and will not increase the pump diameter of the submersible electric plunger pump. The technical scheme of the invention effectively solves the problem of the submersible electric plunger pump in the prior art that the flow area of the electric submersible plunger pump is small without increasing the pump diameter.

Description of drawings

The accompanying drawings constituting a part of the present application are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute an improper limitation of the present invention. In the attached picture:

Fig. 1 shows a schematic diagram of the overall structure of an embodiment of a submersible electric plunger pump according to the present invention.

Wherein, the above-mentioned accompanying drawings include the following reference signs:

10. Motor component; 11. Motor stator; 12. Motor mover; 13. Cable; 20. Outer cylinder component; 21. Screen tube; 22. Outer cylinder structure; 221. Joint; 222. Outer cylinder; 30. Pump Barrel assembly; 31. Pump barrel structure; 32. Swimming valve assembly; 40. Plunger assembly; 41. Fixed valve assembly; 42. Plunger structure; 421. Plunger suspension tube; 422. Plunger sleeve barrel; 50, oil pipe; 60, centralizer; 70, casing.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and examples.

It should be pointed out that the following detailed description is exemplary and intended to provide further explanation to the present application. Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs.

For the convenience of description, spatially relative terms may be used here, such as "on ...", "over ...", "on the surface of ...", "above", etc., to describe the The spatial positional relationship between one device or feature shown and other devices or features. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, devices described as "above" or "above" other devices or configurations would then be oriented "beneath" or "above" the other devices or configurations. under other devices or configurations". Thus, the exemplary term "above" can encompass both an orientation of "above" and "beneath". The device may be otherwise oriented (rotated 90 degrees or at other orientations) and the spatially relative descriptions used herein interpreted accordingly.

Now, exemplary embodiments according to the present application will be described in more detail with reference to the accompanying drawings. These example embodiments may, however, be embodied in many different forms and should not be construed as limited to only the embodiments set forth herein. It should be understood that these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the concept of these exemplary embodiments to those of ordinary skill in the art. In the drawings, the layers are exaggerated for clarity and the thickness of the region, and the same reference numerals are used to designate the same devices, and thus their descriptions will be omitted.

As shown in Figure 1, the submersible electric plunger pump of the present embodiment includes: a motor assembly 10, the motor assembly 10 includes a motor stator 11, a motor mover 12 and a cable 13, and the first end of the motor mover 12 is passed through the motor In the stator 11, the cable 13 is electrically connected to the motor stator 11, and the motor mover 12 performs reciprocating linear motion; it also includes an outer cylinder assembly 20, the outer cylinder assembly 20 includes a screen pipe 21 and an outer cylinder structure 22, and the first end of the screen pipe 21 It is connected with the motor stator 11, and the second end of the screen pipe 21 is connected with the first end of the outer cylinder structure 22; the pump cylinder assembly 30, the pump cylinder assembly 30 includes the pump cylinder structure 31 and the swimming valve assembly 32, the swimming valve assembly The first end of the Er assembly 32 is connected with the second end of the motor mover 12, and the second end of the moving Er assembly 32 is connected with the first end of the pump barrel structure 31; the plunger assembly 40, the plunger assembly 40 Including a fixed valve assembly 41 and a plunger structure 42, the first end of the plunger structure 42 is connected to the fixed valve assembly 41, and the second end of the plunger structure 42 is connected to the second end of the outer cylinder structure 22; the pump The cylinder assembly 30 is located in the cylinder of the outer cylinder assembly 20, the first end of the fixed valve assembly 41 and the plunger structure 42 is located in the cylinder of the pump cylinder assembly 30, the inner diameter of the pump cylinder structure 31 is the same as the first end of the plunger structure 42 to match the outer diameter.

Applying the technical solution of the present invention, when using the electric submersible plunger pump to pump oil, the electric submersible plunger pump is lowered into the casing of the oil well, and when the motor component drives the motor mover to perform a downstroke action, the motor mover drives the The pump barrel assembly moves backward. At this time, the fixed valve assembly is closed under the pressure in the oil pipe, and the floating valve assembly is opened under the pressure of the oil layer, and the oil enters the cavity between the pump barrel assembly and the plunger assembly. Inside. When the motor assembly drives the motor mover to do an upstroke, the motor mover drives the pump barrel assembly to move forward, so that the pressure of the oil entering the cavity between the pump barrel assembly and the plunger assembly rises, and the swimming valve assembly is closed. , the oil cannot flow back, and the pressure of the oil in the cavity between the pump barrel assembly and the plunger assembly rises further, the fixed valve assembly is opened, and then the oil passes through the fixed valve assembly and the plunger structure in turn from the submerged The oil is discharged from the electric plunger pump. The up and down strokes of the above-mentioned motor mover, the forward and backward movements are repeated continuously, and the continuous oil pumping and lifting work of the submersible electric plunger pump can be realized, so that the oil at the bottom of the well is lifted to the wellhead through the oil pipe. In addition, by arranging the pump barrel assembly in the barrel of the outer barrel assembly, and then setting the first end of the plunger assembly in the barrel of the pump barrel assembly, this nesting structure makes the diameter of the swimming valve assembly larger than The diameter of the fixed valve assembly, so that the diameter of the floating valve assembly is increased compared with the diameter of the fixed valve assembly, so that the flow area of the floating valve assembly is relatively increased, and the oil lift is increased. Lifting efficiency, and will not increase the pump diameter of the submersible electric plunger pump. The technical scheme of the invention effectively solves the problem of the submersible electric plunger pump in the prior art that the flow area of the electric submersible plunger pump is small without increasing the pump diameter.

It should be noted that the motor assembly 10 can be a linear motor, a hydraulic push rod and other driving devices that can realize reciprocating linear motion. The diameter of the movable valve assembly 32 is larger than that of the fixed valve assembly 41, thereby relatively increasing the oil passage area of the oil inlet passage, relatively increasing the flow area of the floating valve assembly 32, and reducing frictional resistance , to improve pump efficiency. The fixed valve assembly 41 is built into the pump barrel assembly 30, and the diameter of the fixed valve assembly 41 is relatively reduced compared with the original one. Although the diameter reduction of the fixed valve assembly 41 will increase a certain frictional resistance, but Because the diameter of the movable valve assembly 32 is larger than that of the fixed valve assembly 41, the oil flow rate is relatively increased, and the frictional resistance of the fixed valve assembly 41 can be overcome by means of the thrust of the motor rotor, thereby Does not affect pump efficiency.

As shown in Figure 1, in the technical solution of this embodiment, the outer cylinder structure 22 includes a joint 221 and an outer working cylinder 222, the first end of the outer working cylinder 222 is connected with the second end of the screen pipe 21, and the outer working cylinder 222 The second end of the connector 221 is connected to the first end. The joint 221 is an oil outlet for connecting the external oil pipe 50 and installing the outer cylinder assembly. The outer working cylinder 222 protects and fixes the internal structure. There is a gap between the inner wall of the outer working cylinder 222 and the outer wall of the pump barrel structure 31 to ensure that the movement of the pump barrel is not restricted. The outer working cylinder 222 can act on the pump barrel structure 31. to the guiding role. The connections between the joint 221, the outer working cylinder 222 and the screen pipe 21 can all be connected through thread fit, and the connection between the screen pipe 21 and the motor stator 11 can also be connected through thread fit.

As shown in FIG. 1 , in the technical solution of this embodiment, the electric submersible plunger pump further includes an oil pipe 50 connected to the second end of the joint 221 . The oil pipe 50 is used to transport the oil lifted by the submersible electric plunger pump to the surface. The oil pipe 50 and the joint 221 can be connected through thread fit, and the oil pipe is threadedly connected with sealing performance, so as to ensure a good oil transmission effect.

As shown in Figure 1, in the technical solution of this embodiment, the plunger structure 42 includes a plunger suspension tube 421 and a plunger sleeve 422, the first end of the plunger sleeve 422 is connected to the fixed valve assembly 41, The second end of the plunger sleeve 422 is connected to the first end of the plunger suspension tube 421 , and the second end of the plunger suspension tube 421 is connected to the joint 221 . The plunger suspension tube 421 and the plunger sleeve 422 are oil passages, and the plunger sleeve 422 is used for installing and fixing the valve assembly 41 . The first end of the plunger suspension cylinder 421 extends into the pump cylinder structure 31, so that the length of the external pump cylinder structure 31 can be increased, so that the pump cylinder structure 31 will not collide with the internal plunger sleeve 422 when moving. Structural components play a protective role. The plunger structure and the pump barrel structure are clearance fit.

As shown in FIG. 1 , in the technical solution of this embodiment, the second end of the plunger suspension tube 421 is connected to the inner wall at the middle position of the joint 221 . The above structure makes the oil outlet position of the submersible electric plunger pump have better sealing effect.

As shown in Figure 1, in the technical solution of this embodiment, the second end of the pump cylinder structure 31 is located between the first end of the plunger suspension cylinder 421 and the second end of the plunger suspension cylinder 421, the pump cylinder structure 31 The second end has an inwardly facing flange. The inner diameter of the flange is larger than the outer diameter of the plunger suspension tube 421 and smaller than the outer diameter of the plunger sleeve 422 so that the plunger sleeve 422 forms a limit to the pump barrel structure 31 .

As shown in FIG. 1 , in the technical solution of this embodiment, the inner diameter of the pump barrel structure 31 is in clearance fit with the outer diameter of the first end of the plunger structure 42 . The outer wall of the cylinder of the plunger sleeve 422 cooperates with the inner wall of the pump barrel structure 31 in a gap, so that most of the oil passes through the fixed valve assembly 41, and the oil lost from the gap can be ignored.

As shown in Fig. 1, in the technical solution of the present embodiment, the side of the first end of the movable valve assembly 32 is provided with an oil inlet channel, the plunger structure 42 is a cylindrical structure, and the area of the oil inlet channel is larger than that of the column. The cross-sectional area of the plug structure 42. The oil inlet channel on the floating valve assembly 32 is connected with the cavity between the screen pipe 21 and the pump barrel assembly 30, and by increasing the diameter of the floating valve assembly 32, the frictional resistance is reduced, so that the The oil in the valve assembly 32 can fill the cavity between the pump barrel assembly 30 and the plunger assembly 40, which better ensures the oil lifting efficiency.

As shown in FIG. 1 , in the technical solution of this embodiment, the side of the screen pipe 21 has an oil inlet channel for communicating with the inner space of the outer cylinder assembly 20 and the outer space of the outer cylinder assembly 20 . The oil inlet channel facilitates the oil in the casing 70 to enter the cavity of the outer cylinder structure 22 to prepare for the next step. In addition, the oil inlet channel of the screen tube 21 can be a plurality of through holes for the oil to enter the outer cylinder structure 22, and a filter screen can be set on the surface of the screen tube 21, and the oil liquid can be pre-filtered through the filter screen, thereby protecting Submersible electric plunger pump.

As shown in Figure 1, in the technical solution of this embodiment, the submersible electric plunger pump also includes a centralizer 60, and the centralizer 60 is arranged on the motor stator 11, and is located at one side of the motor stator 11 away from the motor rotor 12. side. The centralizer 60 is mainly to straighten the motor stator 11 to prevent the cable 13 from colliding with the bushing 70. After the cable 13 is energized, the motor mover 12 moves up and down in the motor stator 11. In addition, the outer diameter of the centralizer 60 is greater than the outer diameter of the motor stator 11, so that the cable 13 is located in the space formed between the centralizer 60 and the bushing 70, so that the tension between the cable 13 and the wall of the bushing 70 is better relieved. Wear and tear, effectively protect the cable 13.

It should be noted that the joints in the above structures can all be connected by threaded connections, so as to ensure the stability of the structure and better sealing effect. The stroke length of the motor mover 12 is the same as that of the pump barrel assembly 30, and the length of the pump barrel structure 31 can be determined according to actual conditions to ensure that the pump barrel structure 31 and the plunger assembly 40 do not collide when they move with each other. When the motor mover 12 runs over-travel, it can perform pump collision operation, the fixed valve assembly and the floating valve assembly collide, and the wax, sand, etc. deposited on the pump barrel assembly 30 and the plunger assembly 40 will vibrate. Down, the impact of wax, sand, etc. on the fixed valve assembly 41 and the movable valve assembly 32 is reduced, and the working reliability of the oil well pump system is effectively improved. The overtravel work of the motor mover 12 can be turned on and off through a remote control system. In addition, since the submersible electric plunger pump in the present invention does not increase the pump diameter, it can still effectively ensure that the application range of the submersible electric plunger pump is not affected.

It needs to be further explained that Valve (valve in English and valve in Chinese) is similar to a one-way valve. When the Ver ball leaves the Ver ball seat, the flow channel is opened and the fluid can pass through. When the fluid flows in the reverse direction, the Ver ball sits on the Ver ball seat under the action of pressure (or other force), and the flow channel is closed. , The fluid cannot pass through the valve, and the valve is often used on the pump, especially the multi-piston pump, to ensure the one-way flow of the fluid. Swimming valve refers to drilling and oil production operations. During construction, it is installed on the plunger of the oil well pump to reciprocate with the plunger to discharge the liquid in the pump. Fixed ball means that its installation position is fixed, and there is only movement away from and close to the ball seat between the ball and ball seat. In addition, because the submersible electric plunger pump is not limited by the sucker rod of the pumping unit, the submersible electric plunger pump can not only penetrate deep into vertical wells, but also deep into horizontal wells. After the submersible electric plunger pump is placed in the oil well, the outer cylinder assembly 20 will basically not move again, so the submersible electric plunger pump will basically not wear out with the oil well casing. Compared with the pumping unit as the power unit, the submersible electric plunger pump has the following advantages: (1) the energy saving effect is obvious; (2) there is no sucker rod, which avoids the problem of partial wear of the pipe and rod, and is more suitable For directional wells; (3) Intelligent control can be realized, and the parameters of the submersible electric plunger pump can be adjusted by using the buttons in the ground control cabinet, making parameter adjustment simple and convenient; (4) If it is equipped with a remote monitoring system, remote monitoring can be realized (5) The use of electric drive is more environmentally friendly; (6) Using a linear motor to drive a reciprocating submersible pump does not have the packing box sealing problem of the rod pump lifting technology of the pumping unit, so there is no The problem of oil leakage at the packing box.

It should be noted that the terminology used here is only for describing specific implementations, and is not intended to limit the exemplary implementations according to the present application. As used herein, unless the context clearly dictates otherwise, the singular is intended to include the plural, and it should also be understood that when the terms "comprising" and/or "comprising" are used in this specification, they mean There are features, steps, operations, means, components and/or combinations thereof.

It should be noted that the terms "first" and "second" in the description and claims of the present application and the above drawings are used to distinguish similar objects, but not necessarily used to describe a specific sequence or sequence. It is to be understood that the data so used are interchangeable under appropriate circumstances such that the embodiments of the application described herein, for example, can be practiced in sequences other than those illustrated or described herein. Furthermore, the terms "comprising" and "having", as well as any variations thereof, are intended to cover a non-exclusive inclusion, for example, a process, method, system, product or device comprising a sequence of steps or elements is not necessarily limited to the expressly listed instead, may include other steps or elements not explicitly listed or inherent to the process, method, product or apparatus.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and changes. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims (9)

1. a kind of submersible electric plunger pump, comprises motor assembly (10), and described motor assembly (10) comprises motor stator (11), electric mover (12) and cable (13), and described electric mover ( 12) The first end is passed through the motor stator (11), the cable (13) is electrically connected to the motor stator (11), and the motor mover (12) performs reciprocating linear motion; It is characterized in that it also includes: an outer cylinder assembly (20), the outer cylinder assembly (20) includes a screen pipe (21) and an outer cylinder structure (22), the first end of the screen pipe (21) is connected to the motor stator (11), The second end of the screen pipe (21) is connected to the first end of the outer cylinder structure (22); A pump barrel assembly (30), the pump barrel assembly (30) includes a pump barrel structure (31) and a traveling valve assembly (32), the first end of the swimming valve assembly (32) is connected to the The second end of the motor mover (12) is connected, and the second end of the moving valve assembly (32) is connected with the first end of the pump barrel structure (31); A plunger assembly (40), the plunger assembly (40) comprising a fixed valve assembly (41) and a plunger structure (42), the first end of the plunger structure (42) is connected to the fixed valve assembly (41) are connected, and the second end of the plunger structure (42) is connected with the second end of the outer cylinder structure (22); The pump cylinder assembly (30) is located in the cylinder of the outer cylinder assembly (20), and the first end of the fixed valve assembly (41) and the plunger structure (42) is located in the pump cylinder assembly In the barrel of (30), the inner diameter of the pump barrel structure (31) is compatible with the outer diameter of the first end of the plunger structure (42); The side of the first end of the moving valve assembly (32) is provided with an oil inlet passage, the plunger structure (42) is a cylindrical structure, and the area of the oil inlet passage is larger than that of the plunger structure (42) cross-sectional area. 2. The electric submersible plunger pump according to claim 1, characterized in that, the outer cylinder structure (22) comprises a joint (221) and an outer working cylinder (222), and the outer working cylinder (222) The first end is connected with the second end of the screen pipe (21), and the second end of the outer working cylinder (222) is connected with the first end of the joint (221). 3. The electric submersible plunger pump according to claim 2, characterized in that, the electric submersible plunger pump also includes an oil pipe (50), and the first connection between the oil pipe (50) and the joint (221) The two ends are connected. 4. The electric submersible plunger pump according to claim 2, characterized in that, the plunger structure (42) comprises a plunger suspension tube (421) and a plunger sleeve (422), and the plunger sleeve The first end of the cylinder (422) is connected with the fixed valve assembly (41), the second end of the plunger sleeve (422) is connected with the first end of the plunger suspension cylinder (421), The second end of the plunger suspension tube (421) is connected with the joint (221). 5. The electric submersible plunger pump according to claim 4, characterized in that, the second end of the plunger suspension tube (421) is connected to the inner wall at the middle position of the joint (221). 6. The electric submersible plunger pump according to claim 4, characterized in that, the second end of the pump barrel structure (31) is located between the first end of the plunger suspension tube (421) and the column. Between the second ends of the plug suspension cylinder (421), the second end of the pump cylinder structure (31) has an inward flange. 7. The electric submersible plunger pump according to claim 6, characterized in that, the inner diameter of the pump barrel structure (31) is in clearance fit with the outer diameter of the first end of the plunger structure (42). 8. The electric submersible plunger pump according to claim 1, characterized in that, the side of the screen pipe (21) has an oil inlet channel for communicating with the inner space of the outer cylinder assembly (20) and the Describe the outer space of the outer cylinder assembly (20). 9. The electric submersible plunger pump according to any one of claims 1 to 8, characterized in that, the electric submersible plunger pump also comprises a centralizer (60), and the centralizer (60) is arranged on The motor stator (11) is located on the side of the motor stator (11) away from the motor mover (12).

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