Lead screw driven rodless reciprocating electric submersible pump

Abstract

The utility model provides a lead screw driven rodless reciprocating electric submersible pump which comprises an oil pipe, an oil discharge cavity cover plate, an upper working cavity liquid discharge valve, a cylinder body, an upper working cavity end cover, a lead screw, a plunger, an upper working cavity liquid inlet valve, a lower working cavity end cover, a lower working cavity liquid discharge valve and a lower working cavity liquid inlet valve. The oil discharge cavity cover plate is mounted at the top of the cylinder body, is communicated with the oil pipe and provides an oil discharge channel; oil and gas lifting and conveying are achieved in the motion mode that the lead screw rotates to drive the plunger, and it is guaranteed that high-viscosity, gas-liquid mixed-phase, high-solid-impurity-content crude oil and other multi-phase fluids are conveyed in a high-energy-efficiency and high-displacement mode under the high sand content and various chemical environments.

Description

Technical Field

[0001] The utility model belongs to the technical field of oil and gas exploitation and pressurized transportation, and particularly relates to a screw-driven rodless reciprocating submersible electric pump. Background Art

[0002] With the development and utilization of offshore oil and gas resources, subsea oil and gas lifting and transportation have become an important part of the petroleum industry. Traditional subsea oil and gas transportation mainly relies on mechanical equipment such as centrifugal pumps and screw pumps, and these devices have shown various limitations and disadvantages in long-term applications. For centrifugal pumps: The efficiency of centrifugal pumps is relatively low when dealing with high-viscosity fluids, especially under low-flow conditions, the efficiency further decreases; when working in fluids containing sand or other solid particles, the impeller and pump body of the centrifugal pump are prone to wear; corrosive substances in the seawater environment can accelerate the corrosion of the pump, affecting the life and reliability of the pump; the maintenance cost of centrifugal pumps is relatively high, especially in the subsea environment, the maintenance and replacement costs are even more expensive. For screw pumps: For extremely high-viscosity fluids, the operating efficiency of screw pumps decreases, and they are prone to blockage; as the usage time increases, the volumetric efficiency of screw pumps will decrease due to wear; screw pumps are relatively sensitive to solid particles and impurities and are prone to damage; compared with the screw-driven rodless reciprocating submersible electric pump, the energy consumption of screw pumps is relatively high under certain working conditions.

[0003] The screw-driven rodless reciprocating submersible electric pump is a key device for this purpose, and it is used for oil and gas lifting and transportation in deep-sea environments. Through its reciprocating motion, the screw-driven rodless reciprocating submersible electric pump can effectively handle multiphase fluids, including high-viscosity, gas-liquid mixed-phase, and high-solid-impurity-containing crude oil. This pump is usually designed to withstand the high pressure and low temperature environments of the seabed and has good corrosion resistance. The screw-driven rodless reciprocating submersible electric pump includes a pump body, a motor, a reciprocating mechanism, an oil suction port, and an oil discharge port. The motor drives the reciprocating mechanism to make the piston in the pump body produce reciprocating motion, thereby realizing the suction and discharge of oil. The screw-driven rodless reciprocating submersible electric pump adopts a reciprocating mechanism and high-wear-resistant materials to reduce wear and extend the service life. The piston is designed with special materials and structures to adapt to high-viscosity oil quality and reduce energy consumption; the screw-driven rodless reciprocating submersible electric pump is highly sealed to reduce oil leakage and improve the lifting efficiency. Compared with traditional centrifugal pumps and single-screw pumps, the screw-driven rodless reciprocating submersible electric pump has many advantages: high efficiency: the optimized reciprocating mechanism and piston design improve the operation efficiency in high-viscosity oil fields; long life: the use of high-wear-resistant materials significantly extends the service life of the equipment; low maintenance cost: the structure is simple and easy to maintain, reducing the operating cost; strong environmental adaptability: it can operate stably in high-sand-content and various chemical environments. Content of the Utility Model

[0004] For the above purposes, the present utility model provides a screw-driven rodless reciprocating submersible electric pump, which realizes oil and gas lifting and transportation through the movement form of driving a plunger by the rotation of a screw rod, ensuring high-energy efficiency and high displacement in transporting high-viscosity, gas-liquid mixed-phase, high-solid-impurity crude oil and other multiphase fluids under high sand content and various chemical environments.

[0005] The technical solution adopted by the present utility model is as follows: A screw-driven rodless reciprocating submersible electric pump includes a tubing, an oil discharge chamber cover plate, an upper working chamber liquid discharge valve, a cylinder block, an upper working chamber end cover, a screw rod, a plunger, an upper working chamber liquid inlet valve, a lower working chamber end cover, a lower working chamber liquid discharge valve, and a lower working chamber liquid inlet valve; The oil discharge chamber cover plate is installed on the top of the cylinder block and is connected to the tubing to provide an oil discharge channel; The upper working chamber end cover and the lower working chamber end cover are respectively installed at the upper and lower ends of the cylinder block to realize the installation and positioning of the screw rod; The plunger is matched with the screw rod, installed in the cylinder block, coaxial with the cylinder block, and realizes reciprocating up and down movement under the drive of the screw rod, forming a periodically changing working chamber between the upper working chamber end cover and the lower working chamber end cover to realize the suction, pressurization, and discharge of the medium; The upper working chamber liquid discharge valve, the lower working chamber liquid discharge valve, the upper working chamber liquid inlet valve, and the lower working chamber liquid inlet valve are respectively installed at the liquid inlet end and the liquid discharge end of the cylinder block to control the entry and discharge of oil.

[0006] Further, in the present utility model, the screw rod rotates periodically forward and backward under the drive of a motor, thereby driving the cooperating plunger to reciprocate up and down along the axis; During the reciprocating movement of the plunger, a periodically changing upper working chamber and a lower working chamber are formed between the plunger and the upper working chamber end cover and the lower working chamber end cover; When the plunger moves upward, the volume of the lower working chamber increases, and under the action of the pressure difference, the lower working chamber liquid inlet valve opens, and the oil continuously enters the working chamber, while the volume of the upper working chamber decreases, the internal oil pressure increases, and is discharged through the upper working chamber liquid discharge valve; On the contrary, when the plunger moves downward, the volume of the upper working chamber increases, and under the action of the pressure difference, the upper working chamber liquid inlet valve opens, and the oil continuously enters the working chamber, while the volume of the lower working chamber decreases, the internal oil pressure increases, and is discharged through the lower working chamber liquid discharge valve; With the periodic change of the volumes of the upper working chamber and the lower working chamber, finally, the oil is sucked in from the liquid inlet end, pressurized, and discharged to the oil discharge chamber to complete the pressurization and transportation of the medium.

[0007] Further, in the present utility model, the upper working chamber liquid inlet valve, the upper working chamber liquid inlet and discharge channel, the upper working chamber, and the upper working chamber liquid discharge valve together constitute the upper working chamber medium pressurization and transportation channel; The lower working chamber liquid inlet valve, the lower working chamber liquid inlet and discharge channel, the lower working chamber, and the lower working chamber liquid discharge valve together constitute the lower working chamber medium pressurization and transportation channel; The upper working chamber liquid discharge valve, the lower working chamber liquid discharge valve, the upper working chamber liquid inlet valve, and the lower working chamber liquid inlet valve control the entry and discharge of oil in the channel through the pressure difference.

[0008] Furthermore, a static sealing device is provided between the oil drainage cavity cover plate and the cylinder block of the present utility model to prevent oil leakage; a static sealing device is provided between the upper working cavity end cover and the cylinder block to prevent high-pressure oil from leaking from the drainage cavity A into the upper working cavity B; a dynamic sealing device is provided between the plunger, the lead screw and the cylinder block to prevent oil from leaking between the upper working cavity B and the lower working cavity C.

[0009] Furthermore, a bidirectional thrust bearing is arranged in the upper working cavity end cover and the lower working cavity end cover of the present utility model. The bearing is connected to the lead screw to control the pure rotational movement of the lead screw in the working cavity. At the same time, it ensures that the lead screw always pulls the plunger during rotation, reduces the thrust on the lead screw, and extends the service life of the lead screw.

[0010] Furthermore, the upper working cavity, the upper working cavity inlet and outlet channels, the lower working cavity, and the lower working cavity inlet and outlet channels of the present utility model work in parallel. After the individual upper working cavity inlet and outlet valve group or the lower working cavity inlet and outlet valve group is damaged, the remaining working cavity can still continue to work, extending the service life of the submersible electric pump.

[0011] Furthermore, the cylinder block and the combined plunger of the present utility model have two combined configurations, both of which are composed of a working cavity drainage valve, a lower working cavity inlet valve, an upper working cavity drainage valve, and an upper working cavity inlet valve. The upper drainage cavity D and the lower drainage cavity E are semi-circular ring channels, the supporting plunger and the upper working cavity B and the lower working cavity C are cylinders, and the cylinder block as a whole is a jacketed cylinder block. This configuration can effectively save the pump body space, increase the working cavity volume, and the middle of the annular jacket is separated by two rib plates. It is suitable for large-displacement oil and gas transportation, can transport fluids at high frequencies, and can minimize fatigue damage during the transmission process.

[0012] Furthermore, the lower working cavity drainage valve, the lower working cavity inlet valve, the upper working cavity drainage valve, and the upper working cavity inlet valve of the present utility model are all one-way ball valves.

[0013] Furthermore, the cylinder block described in this article is integrally cast, and the rest of the components are bolted and installed on the cylinder block, reducing the installation cost of the device.

[0014] Furthermore, the lead screw in the present utility model can use a ball screw or a threaded screw, etc.

[0015] The present utility model has the following advantages compared with the prior art:

[0016] 1) The lead screw-driven rodless reciprocating submersible electric pump proposed by the present utility model adopts an advanced lead screw drive technology, effectively improving the energy conversion efficiency. Under the same power conditions, the pump can achieve higher fluid transportation efficiency, and is particularly suitable for complex undersea and energy-intensive oil and gas transportation environments;

[0017] 2) The rodless reciprocating submersible electric pump driven by a lead screw proposed in the present utility model takes into account the sand grains and impurities often contained in undersea oil and gas. By using wear-resistant materials and optimizing the structure, the durability and reliability in fluid containing impurities are greatly improved;

[0018] 3) The rodless reciprocating submersible electric pump driven by a lead screw proposed in the present utility model simplifies the overall structure and maintenance work through the design of two parallel working chambers, especially in the difficult-to-access undersea environment. Its design makes the long-term operation of the pump more stable and reduces the operation interruption caused by maintenance and repair;

[0019] 4) The rodless reciprocating submersible electric pump driven by a lead screw proposed in the present utility model ensures the pure rotational motion of the lead screw through the design of thrust bearings at both ends of the lead screw, effectively reducing the overall length of the pump and ensuring that the lead screw is in a tensile state during reciprocating rotation. This design reduces the stress on the lead screw, makes the long-term operation of the pump more stable, and extends the service life of the pump;

[0020] 5) The rodless reciprocating submersible electric pump driven by a lead screw proposed in the present utility model is specially designed for the complex chemical properties of undersea oil and gas and can more effectively handle fluids with different viscosities and chemical compositions. This adaptability gives the lead screw-driven submersible screw pump obvious advantages in the changing undersea oil and gas transportation environment.

[0021] 6) The rodless reciprocating submersible electric pump driven by a lead screw proposed in the present utility model takes into account the usage requirements under different operating conditions and provides two cylinder blocks with different structural forms, which can respectively meet the usage requirements of large displacement and low frequency as well as small displacement and high frequency, expanding the application field of the submersible electric pump. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The present utility model will be further described below with reference to the drawings:

[0023] Figure 1 It is a schematic diagram of Configuration I of the submersible electric pump of the present utility model;

[0024] Figure 2 It is a schematic diagram of Configuration II of the submersible electric pump of the present utility model;

[0025] Figure 3 It is a multi-section sectional view of Configuration I of the submersible electric pump of the present utility model;

[0026] Figure 4 It is a multi-section sectional view of Configuration II of the submersible electric pump of the present utility model;

[0027] Figure 5 It is a three-dimensional model of Configuration I of the cylinder block of the submersible electric pump of the present utility model;

[0028] Figure 6This is the 3D model of the cylinder configuration II of the submersible electric pump of the present utility model.

[0029] Reference numerals in the figure: 1 - tubing; 2 - drain cavity cover plate; 3 - upper working cavity drain valve; 4 - cylinder block; 5 - upper working cavity end cover; 6 - lead screw; 7 - plunger; 8 - upper working cavity inlet valve; 9 - lower working cavity end cover; 10 - lower working cavity drain valve; 11 - lower working cavity inlet valve. Specific embodiments

[0030] The present utility model will be further described in detail below with reference to the attached drawings and examples:

[0031] Example 1

[0032] Figure 1 Schematic diagram of the configuration I of the submersible electric pump of the present utility model, a rodless reciprocating submersible electric pump driven by a lead screw, used for oil and gas lifting, mainly including tubing 1, drain cavity cover plate 2, upper working cavity drain valve 3, cylinder block 4, upper working cavity end cover 5, lead screw 6, plunger 7, upper working cavity inlet valve 8, lower working cavity end cover 9, lower working cavity drain valve 10, and lower working cavity inlet valve 11. Among them, the drain cavity cover plate 2 is installed on the top of the cylinder block 4 and is connected to the tubing 1 at the same time, forming a drain channel, which allows the oil to be discharged smoothly from the inside of the cylinder block. At the same time, an inner cylinder is arranged inside the cylinder block 4, and the inner cylinder divides the inside of the cylinder block 4 into an interlayer channel between the outer wall of the inner cylinder and the inner wall of the cylinder block 4 and a channel inside the inner cylinder. The upper working cavity end cover 5 and the lower working cavity end cover 9 are respectively fixedly installed at the upper and lower ends of the inner space of the inner cylinder. These two end covers not only provide the necessary support for the installation and positioning of the lead screw 6, but also ensure the structural stability of the whole mechanism. In this structure, the plunger 7 is slidably installed between the upper working cavity end cover 5 and the lower working cavity end cover 9. The plunger 7 is used in cooperation with the lead screw 6. The upper end of the lead screw 6 is rotationally supported by the upper working cavity end cover 5, and the lower end is rotationally supported by the lower working cavity end cover 9. The plunger 7 moves up and down axially under the drive of the forward and reverse rotation of the lead screw 6. To prevent the plunger 7 from rotating with the lead screw 6, the inner wall surface of the inner cylinder and the outer wall surface of the plunger are in keyway fit, or the inner cylinder and the plunger with non-circular cross-sections can be used. This movement enables the plunger 7 to form a periodically changing working chamber between the upper working cavity end cover 5 and the lower working cavity end cover 9, thereby realizing the processes of medium suction, pressurization, and discharge. In addition, the upper working cavity drain valve 3 and the lower working cavity drain valve 10 are installed near the upper end (drain end) of the interlayer channel, and the upper working cavity inlet valve 8 and the lower working cavity inlet valve 11 are respectively installed at the lower end (inlet end) of the interlayer channel.

[0033] Figure 3 This is the multi-section sectional view of the configuration I of the submersible electric pump of the present utility model, Figure 5 This is the 3D model of the cylinder configuration I of the submersible electric pump of the present utility model, combined with Figure 3 and Figure 5, preferably, an upper ring plate and a lower ring plate are respectively arranged near the upper end and the lower end of the interlayer channel. The upper working chamber drain valve 3 and the lower working chamber drain valve 10 are one-way valves arranged on the upper ring plate and opening towards the oil pipe 1. The upper working chamber inlet valve 8 and the lower working chamber inlet valve 11 are one-way valves arranged on the lower ring plate and opening towards the inside of the cylinder block 4. And the interlayer channel is divided into two left and right spaces by longitudinal rib plates (not shown in the figure), namely the upper drain chamber D on the left side and the lower drain chamber E on the right side. The upper and lower ends of the two longitudinal rib plates are respectively fixed to the upper ring plate and the lower ring plate. The upper working chamber drain valve 3 and the upper working chamber inlet valve 8 are arranged corresponding to the upper drain chamber D to control the lifting action of the space on this side. The lower working chamber drain valve 10 and the lower working chamber inlet valve 11 are arranged corresponding to the lower drain chamber E to control the lifting action of the space on this side. A channel connecting the upper working chamber B of the plunger 7 and the upper drain chamber D is opened on the side wall of the inner cylinder near the upper working chamber end cover 5, and a channel connecting the lower working chamber C of the plunger 7 and the lower drain chamber E is opened on the side wall near the lower working chamber end cover 9. And a plurality of oil drain through holes are opened on the side wall of the part of the inner cylinder between the upper ring plate and the oil drain chamber cover plate 2. The main function of these valves is to control the entry and discharge of oil to ensure the normal operation of the entire system. Through the coordinated work of these components, the effective operation of the hydraulic system and the effective transmission of the medium are guaranteed.

[0034] During the working process of the adjusting mechanism, under the control of the control system, the lead screw 6 rotates forward and reverses periodically driven by the motor. This rotation drives the cooperating plunger 7 to reciprocate up and down along the axis. During this movement process, periodic upper working chamber B and lower working chamber C are formed between the plunger 7 and the upper working chamber end cover 5 and the lower working chamber end cover (9). When the plunger 7 moves upward, the volume of the lower working chamber C increases. At this time, due to the pressure difference, the lower working chamber inlet valve 11 opens, allowing oil to continuously flow into the working chamber. At the same time, the volume of the upper working chamber B decreases, resulting in an increase in the oil pressure therein, which is discharged through the upper working chamber drain valve 3. On the contrary, when the plunger 7 moves downward, the volume of the upper working chamber B increases. Similarly, due to the pressure difference, the upper working chamber inlet valve 8 opens, allowing oil to flow in. At this time, the volume of the lower working chamber C decreases, and the oil pressure inside it increases, which is discharged through the lower working chamber drain valve 10. This periodic change in the volumes of the upper working chamber B and the lower working chamber C realizes the processes of oil suction, pressurization, and discharge. The oil is sucked in through the liquid inlet end, pressurized, and discharged from the liquid discharge end, thus completing the functions of pressurization and conveying of the medium. In this way, the system effectively controls the flow of oil, ensuring the stable operation and high performance of the hydraulic system.

[0035] Embodiment 2

[0036] See Figure 2, which is a schematic diagram of the II configuration of the submersible electric pump of the present utility model. The structures of the upper working chamber end cover 5 and the lower working chamber end cover 9 are designed in a T shape, so that the inner diameter of the inner cylinder is increased, the working volumes of the upper working chamber B and the lower working chamber C are increased, and the volumes of the upper liquid discharge chamber D and the lower liquid discharge chamber E on the right side are reduced. When the plunger 7 moves up and down, the internal pressure in the upper liquid discharge chamber D and the lower liquid discharge chamber E on the right side reacts more sensitively, and the opening and closing of each liquid inlet valve and liquid discharge valve are faster, improving the overall working efficiency of the submersible electric pump of the present utility model. Figure 4 It is a multi-section sectional view of the II configuration of the submersible electric pump of the present utility model. Figure 6 It is a three-dimensional model of the cylinder block configuration II of the submersible electric pump of the present utility model. The shape of the longitudinal rib plate is shown in this embodiment. The annular space between the cylinder block 4 and the inner cylinder is divided into two semi-circular ring cavities with the two symmetrically arranged rib plates.

[0037] Although the specific implementation manners of the present utility model are described above in conjunction with the drawings, it is not a limitation to the protection scope of the present utility model. Those skilled in the art should understand that based on the technical solution of the present utility model, various modifications or deformations that can be made by those skilled in the art without creative efforts are still within the protection scope of the present utility model.

Claims

1. A screw-driven rodless reciprocating submersible electric pump, characterized in that: It includes an oil pipe (1), an oil drain cavity cover plate (2), an upper working cavity liquid discharge valve (3), a cylinder block (4), an upper working cavity end cover (5), a lead screw (6), a plunger (7), an upper working cavity liquid inlet valve (8), a lower working cavity end cover (9), a lower working cavity liquid discharge valve (10), and a lower working cavity liquid inlet valve (11); The oil drain cavity cover plate (2) is installed on the top of the cylinder block (4), and a through hole communicating with the oil pipe (1) is provided on the oil drain cavity cover plate (2); an inner cylinder is arranged inside the cylinder block (4), and the inner cylinder divides the inside of the cylinder block (4) into a cylindrical space inside the inner cylinder and an annular space outside the inner cylinder; the upper working cavity end cover (5) and the lower working cavity end cover (9) are respectively installed at the upper end and the lower end inside the inner cylinder to respectively support the positioning and rotation of the upper and lower parts of the lead screw (6); the plunger (7) is only installed in the inner cylinder to slide up and down, and the lead screw (6) acts on the plunger to drive the plunger (7) to perform reciprocating up and down motion; An upper ring plate and a lower ring plate are respectively arranged at the upper end and the lower end near the annular space. The upper working cavity liquid discharge valve (3) and the lower working cavity liquid discharge valve (10) are one-way valves arranged on the upper ring plate, and the upper working cavity liquid inlet valve (8) and the lower working cavity liquid inlet valve (11) are one-way valves arranged on the lower ring plate.

2. The submersible electric pump according to claim 1, further characterized in that: Two longitudinally extending rib plates are arranged in the annular space to divide the annular space into an upper liquid discharge cavity D and a lower liquid discharge cavity E; the upper working cavity liquid discharge valve (3) and the upper working cavity liquid inlet valve (8) are arranged corresponding to the upper liquid discharge cavity D, and the lower working cavity liquid discharge valve (10) and the lower working cavity liquid inlet valve (11) are arranged corresponding to the lower liquid discharge cavity E; An upper working cavity B is formed between the plunger (7) and the upper working cavity end cover (5), a lower working cavity C is formed between the plunger (7) and the lower working cavity end cover (9), the upper working cavity B communicates with the upper liquid discharge cavity D, and the lower working cavity C communicates with the lower liquid discharge cavity E.

3. The submersible electric pump according to claim 2, further characterized in that: The cross-sections of the upper working cavity end cover (5) and the lower working cavity end cover (9) are both T-shaped, and their large-diameter ends are arranged opposite to each other. The upper and lower ends of the inner cylinder are respectively fixed on the large-diameter ends of the upper working cavity end cover (5) and the lower working cavity end cover (9) to fixedly install the inner cylinder inside the cylinder block (4).

4. The submersible electric pump according to any one of claims 1-3, further characterized in that: The opening directions of the upper working cavity liquid discharge valve (3) and the lower working cavity liquid discharge valve (10) are towards the direction of the oil pipe (1), and the opening directions of the upper working cavity liquid inlet valve (8) and the lower working cavity liquid inlet valve (11) are towards the inside direction of the cylinder block (4).

5. The submersible electric pump according to claim 4, further characterized in that: The valve cores of the upper working cavity liquid discharge valve (3), the lower working cavity liquid discharge valve (10), the upper working cavity liquid inlet valve (8), and the lower working cavity liquid inlet valve (11) are all spherical.

6. The submersible electric pump according to any one of claims 1-3, further characterized in that: A static sealing device is provided between the oil drain cavity cover plate (2) and the cylinder block (4) to prevent oil leakage; a static sealing device is provided between the upper working cavity end cover (5) and the inner cylinder; a dynamic sealing device is provided between the plunger (7) and the lead screw (6) to prevent oil and impurities from flowing into the connection between the plunger and the lead screw, wearing the lead screw and the plunger, and at the same time preventing oil leakage between the upper working cavity B and the lower working cavity C.

7. The submersible electric pump according to any one of claims 1-3, further characterized in that: A bi-directional thrust bearing is installed inside the upper working chamber end cover (5) and the lower working chamber end cover (9). The bearing is connected to the lead screw (7) to control the pure rotational movement of the lead screw in the working chamber. At the same time, it ensures that the lead screw always maintains a pulling state on the plunger during rotation, reducing the thrust on the lead screw and extending the service life of the lead screw.

8. The submersible electric pump according to any one of claims 1-3, further characterized in that: The forward and reverse rotation of the lead screw is achieved by connecting a servo motor or a bi-directional motor.

9. The submersible electric pump according to any one of claims 1-3, further characterized in that: The cylinder block (4), the inner cylinder, and two longitudinal rib plates are integrally cast. The remaining components are bolted and installed on the cylinder block.

10. The submersible electric pump according to any one of claims 1-3, further characterized in that: The lead screw can be a ball screw or a threaded screw.

Images