Series-arranged electric high-speed booster pump matched with nonmetallic cable pipe for oil and gas well

Abstract

The application discloses a cascade type electric high-speed well bottom booster pump matched with a nonmetal cable pipe of an oil and gas well and relates to the field of booster pumps. The cascade type electric high-speed well bottom booster pump matched with the nonmetal cable pipe of the oil and gas well comprises a cascade type inclined flow well bottom booster pump accommodated in a casing pipe, a carrier wave sensor arranged at an air inlet end of the cascade type inclined flow well bottom booster pump and a multi-channel cable pipe connected with an air outlet end. The cascade type inclined flow well bottom booster pump comprises at least two-stage compressor units, and the air paths of the compressor units are connected in series, and the driving motor circuits are connected in parallel. The multi-channel cable pipe is internally provided with a central gas pipe channel serving as an output path of natural gas, circumferentially provided with cable channels and the like, and used for supplying power to the motor of each stage of compressor and providing a signal path for the carrier wave sensor. The application can effectively overcome the pipeline resistance through the multi-stage active pressurization at the well bottom, so that a low-pressure well which cannot be exploited by a traditional technology can be restored to production. The design constitutes a complete downhole gas production system of a natural gas well.

Description

Technical Field

[0001] This application relates to the field of booster pump technology, and in particular to a cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells. Background Technology

[0002] During natural gas well production, as natural gas reserves gradually decrease, formation pressure continuously declines. When the bottomhole flowing pressure can no longer overcome the resistance within the well casing, the gas well enters the artificial intervention recovery stage. Existing artificial gas production technologies mainly include bubble drainage, gas lift, pumping and drainage, or combinations thereof.

[0003] However, these traditional methods have limited effectiveness for low-yield old wells or marginal wells with low gas reserves and low formation pressure, and are usually accompanied by high investment and high costs. They may even shorten the overall recovery life of gas wells due to improper processes. Summary of the Invention

[0004] This application provides a cascade-type bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells, thus solving the problems mentioned in the background art.

[0005] This application provides a cascade-type bottom-hole electric high-speed booster pump for use with non-metallic cable-laying tubing in oil and gas wells, comprising: a cascade-type inclined-flow bottom-hole booster pump, housed within the casing of the oil and gas well, with its inlet end used to draw in natural gas from the bottom of the well; a carrier wave sensor, disposed at the inlet end of the cascade-type inclined-flow bottom-hole booster pump, used to collect downhole formation parameters in real time and transmit data via power line carrier communication; and a multi-channel cable-laying tubing, its lower end connected to the outlet end of the cascade-type inclined-flow bottom-hole booster pump, and its upper end extending to the wellhead; wherein... The cascade-type inclined flow bottom-hole booster pump includes at least two compressor units, and the gas flow channels of each compressor unit are connected in series to form a continuous series booster gas path; the drive motors of each compressor unit are connected through parallel circuits; the multi-channel cable laying pipe has a composite channel structure, with a central gas pipe channel in the middle and at least one independent cable channel in its circumference; the inner diameter of the central gas pipe channel is smaller than the inner diameter of a conventional oil production pipe, and it is connected to the gas outlet end of the cascade-type inclined flow bottom-hole booster pump;

[0006] In one possible implementation, the compressor unit includes: a motor housing with a sealed interior; a drive motor housed within the motor housing; and a mixed-flow compressor impeller connected to the output end of the drive motor and rotatably connected to the inlet end of the motor housing; wherein an annular airflow channel is formed between the outer wall of the motor housing and the inner wall of the sleeve; and the sleeve is provided with an electrical interface communicating with the cable channel of the multi-channel cable duct for connecting to power and carrier signals.

[0007] In one possible implementation, the compressor unit further includes a guide tail section disposed at the outlet end of the motor housing; the guide tail section is configured to converge the gas passage cross-section at its outlet end to a preset size, the preset size being matched with the air intake requirements of the mixed-flow compressor impeller of the next stage compressor unit.

[0008] In one possible implementation, the outer wall of the motor housing is provided with a spiral oblique flow air passage groove along its axial direction; the spiral oblique flow air passage groove and the inner wall of the sleeve form the annular air flow channel.

[0009] In one possible implementation, the drive motor is a permanent magnet synchronous high-speed motor.

[0010] In one possible implementation, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable conduit for oil and gas wells also includes a sand-proof pipe string; the sand-proof pipe string is located at the air inlet end of the cascade inclined flow bottom-hole booster pump and is used to filter solid impurities in the formation.

[0011] In one possible implementation, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable laying pipe for the oil and gas well also includes a centralizer; the centralizer is disposed on the outer wall of the multi-channel cable laying pipe and is used to center the multi-channel cable laying pipe within the casing.

[0012] In one possible implementation, the total pressure ratio of the cascaded inclined flow bottom booster pump is 1.2 to 3.0, and the rotational speed of each compressor unit is in the range of 15,000 to 50,000 r / min.

[0013] In one possible implementation, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable laying pipe for the oil and gas well also includes wellhead hanging hardware; the wellhead hanging hardware is disposed at the top of the multi-channel cable laying pipe.

[0014] One or more technical solutions provided in the embodiments of this application have at least the following technical effects:

[0015] This application provides a cascaded bottom-hole electric high-speed booster pump for use with non-metallic cable-stayed tubing in oil and gas wells, comprising a cascaded inclined flow bottom-hole booster pump, a carrier sensor, and a multi-channel cable-stayed tubing. This application uses cables within the multi-channel cable-stayed tubing to power parallel drive motors and the carrier sensor, driving at least two series-connected compressor units to sequentially compress the bottom-hole natural gas in multiple stages, forming a continuous pressurized gas path. Simultaneously, downhole data collected by the carrier sensor is transmitted to the surface via power line carrier communication through the same cable. The pressurized natural gas is efficiently lifted to the wellhead through a small-diameter central gas pipe channel in the middle of the multi-channel cable-stayed tubing. This integrated solution directly addresses the challenges of exploiting low-production, low-pressure wells, effectively overcoming pipeline resistance through active bottom-hole pressurization, enabling production to resume in low-pressure wells that cannot be exploited using traditional methods. The integrated multi-channel cable-stayed tubing and small-diameter central gas pipe channel design reduces flow resistance and operating costs. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the accompanying drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of the structure of a cascade bottom-hole electric high-speed booster pump for use with non-metallic cable pipes in oil and gas wells, provided in an embodiment of this application.

[0018] Figure 2 A series gas flow path model for each stage of the compressor unit provided in the embodiments of this application;

[0019] Figure 3 This is a schematic diagram of the compressor unit provided in the embodiments of this application;

[0020] Figure 4 This is a schematic diagram of the parallel circuit connection of the drive motors of each stage of the compressor unit provided in the embodiments of this application.

[0021] Icons: 1-Cascade-type mixed-flow bottom-hole booster pump; 11-Compressor unit; 111-Motor housing; 1111-Helical mixed-flow air passage groove; 112-Drive motor; 113-Mixed-flow compressor impeller; 114-Guide tail section; 2-Casing; 3-Carrier sensor; 4-Multi-channel cable laying pipe; 5-Sand control pipe string; 6-Center; 7-Wellhead hanging hardware; 8-Channel body; 9-Cable; 10-Plug-in power terminal. Detailed Implementation

[0022] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0023] In the description of the embodiments of this application, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing the embodiments of this application and for simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Furthermore, the terms "installed," "connected," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0024] This application provides a cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells, such as... Figures 1 to 4 As shown. The non-metallic cable casing of this oil and gas well is equipped with a cascade bottom-hole electric high-speed booster pump, which includes a cascade inclined flow bottom-hole booster pump 1, a carrier sensor 3, and a multi-channel cable casing 4. The cascade inclined flow bottom-hole booster pump 1 is housed within the casing 2 of the oil and gas well, and its air inlet is used to draw in natural gas from the bottom of the well. The carrier sensor 3 is located at the air inlet of the cascade inclined flow bottom-hole booster pump 1 and is used to collect downhole formation parameters in real time and transmit the data via power line carrier communication. Specifically, the carrier sensor 3 is coupled to a cable 9, modulating the collected parameter signals onto the carrier frequency of the power supply cable 9, which is then demodulated and processed by the ground control system to achieve bidirectional data transmission in the power supply circuit.

[0025] The lower end of the multi-channel cable pipe 4 is connected to the outlet end of the cascade-type inclined flow bottom-hole booster pump 1, and the upper end extends to the wellhead. The cascade-type inclined flow bottom-hole booster pump 1 includes at least two compressor units 11, with the gas channels of each compressor unit 11 connected in series to form a continuous series booster gas path. The drive motors 112 of each compressor unit 11 are connected via parallel circuits. The multi-channel cable pipe 4 has a composite channel structure, with a central gas pipe channel in its middle and at least one independent cable channel circumferentially arranged therearound. The inner diameter of the central gas pipe channel is smaller than that of a conventional oil production pipe and is connected to the outlet end of the cascade-type inclined flow bottom-hole booster pump 1. The cable 9 within the cable channel provides power to the drive motors 112 of each stage of the parallel circuit and the carrier sensor 3, and constitutes the transmission medium for power line carrier communication.

[0026] It should be noted that this application uses the cable 9 in the multi-channel cable pipe 4 to power the parallel drive motors 112 and carrier sensors 3, driving at least two series-connected compressor units 11 to sequentially compress the bottom-hole natural gas in multiple stages, forming a continuous pressurized gas path. Simultaneously, downhole data collected by the carrier sensors 3 is transmitted to the surface via power line carrier communication through the same cable 9. The pressurized natural gas is efficiently lifted to the wellhead through the small-diameter central gas pipe channel in the middle of the multi-channel cable pipe 4. This integrated solution directly addresses the challenges of exploiting low-production, low-pressure wells, effectively overcoming pipeline resistance through active bottom-hole pressurization, enabling low-pressure wells that cannot be exploited using traditional methods to resume production. The integrated multi-channel cable pipe 4 and small-diameter central gas pipe channel design reduce flow resistance and operating costs.

[0027] In this embodiment, the compressor unit 11 includes a motor housing 111, a drive motor 112, and a mixed-flow compressor impeller 113. The motor housing 111 has a sealed interior. The drive motor 112 is housed within the motor housing 111. The mixed-flow compressor impeller 113 is connected to the output end of the drive motor 112 and rotatably connected to the inlet end of the motor housing 111. An annular airflow channel is formed between the outer wall of the motor housing 111 and the inner wall of the casing 2. The casing 2 is provided with an electrical interface communicating with the cable channel of the multi-channel cable laying pipe 4 for receiving power and carrier signals. This electrical interface communicates with the cable channel of the multi-channel cable laying pipe 4 to reliably connect the power and carrier signals from the cable 9 to the downhole equipment housed within the casing 2.

[0028] It should be noted that this application seals the drive motor 112 within the motor housing 111 and constructs an annular gas flow channel between the motor housing 111 and the casing 2. This design has the following advantages: it greatly saves downhole space, laying a structural foundation for achieving multi-stage series connection and obtaining a high pressure ratio; it completely isolates the core drive components from the complex natural gas flow in the well, fundamentally improving the long-term operational reliability and safety of the drive motor 112 under harsh well conditions; and the annular gas flow channel cleverly utilizes the natural environment downhole, providing an effective heat dissipation path for the drive motor 112.

[0029] In this embodiment, the compressor unit 11 further includes a guide tail section 114 disposed at the outlet end of the motor housing 111. The guide tail section 114 is configured to converge the gas passage cross-section at its outlet end to a preset size, which matches the air intake requirements of the diagonal flow compressor impeller 113 of the next stage compressor unit 11.

[0030] It should be noted that this application effectively regulates the airflow pattern by converging the cross-section of the high-speed gas flow channel after the current stage pressurization to a preset size that matches the intake requirements of the impeller 113 of the next stage mixed-flow compressor. This smoothly guides the gas into the next stage, reduces eddies and impact losses at the interstage connection, and ensures that the gas kinetic energy is efficiently converted into pressure energy. As a result, the series-connected compressor units 11 can smoothly transition and work together, ultimately ensuring that the entire cascaded mixed-flow well bottom booster pump 1 achieves the designed overall boosting efficiency and operational stability.

[0031] In this embodiment, a spiral-shaped oblique flow air passage groove 1111 is provided circumferentially along the axial direction of the outer wall of the motor housing 111. The spiral-shaped oblique flow air passage groove 1111 and the inner wall of the sleeve 2 form an annular air flow channel.

[0032] It should be noted that the spiral flow channel formed by the spiral oblique flow channel groove 1111 can conform to the gas flow trajectory, effectively guide the airflow to flow in the predetermined spiral direction, and reduce frictional resistance and local eddy loss. This structure maximizes the gas flow area within the limited wellbore space, while enhancing the orderliness of the airflow organization through the wall effect.

[0033] In this embodiment, the drive motor 112 is a permanent magnet synchronous high-speed motor.

[0034] Furthermore, the sleeve 2 of this application is provided with a channel body 8 corresponding to the cable channel of the multi-channel cable laying pipe 4, and a cable 9 is installed in the channel body 8. This application uses a 3-660V plug-in cable as the power supply line for the parallel motor, which is connected to the drive motor 112 through a plug-in power terminal 10. The drive motor 112 is a permanent magnet synchronous high-speed motor, and its operation is controlled by a ground control system.

[0035] In this embodiment, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable conduit for oil and gas wells also includes a sand-proof pipe string 5. The sand-proof pipe string 5 is located at the air inlet end of the cascade inclined flow bottom-hole booster pump 1 and is used to filter solid impurities in the formation.

[0036] It should be noted that the sand-proof pipe string 5 of this application can effectively block solid impurities such as sand and rock fragments from entering the high-speed rotating compressor unit 11 with natural gas. This fundamentally avoids the high-speed erosion and wear of solid particles on the impeller 113 of the mixed flow compressor, as well as the potential damage to the sealing structure of the motor housing 111. This ensures the long-term operational stability and service life of the cascade mixed flow bottom-hole booster pump 1 under complex formation conditions.

[0037] In this embodiment, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable laying pipe for oil and gas wells also includes a centralizer 6. The centralizer 6 is disposed on the outer wall of the multi-channel cable laying pipe 4 and is used to center the multi-channel cable laying pipe 4 within the casing 2.

[0038] In this embodiment, the total pressure ratio of the cascaded inclined flow bottom booster pump 1 is 1.2 to 3.0, and the rotational speed of each stage compressor unit 11 is 15,000 to 50,000 r / min.

[0039] It should be noted that a moderate total pressure ratio range can meet the lifting requirements of most low-pressure gas wells while avoiding the efficiency decline and structural complexity caused by excessively high single-stage pressure ratios. The high-speed design of 15,000 to 50,000 r / min per stage allows the single-stage compressor to operate with high efficiency even under the extreme size constraints of the wellbore. Through the technical path of "small number of stages and high speed", the optimal balance of power, efficiency and volume is finally achieved in the narrow downhole space, thus achieving the expected production increase target.

[0040] In this embodiment, the cascade bottom-hole electric high-speed booster pump used with the non-metallic cable laying pipe for oil and gas wells also includes a wellhead hanging hardware 7. The wellhead hanging hardware 7 is disposed on the top of the multi-channel cable laying pipe 4.

[0041] It should be noted that this application achieves reliable suspension and force support for the entire downhole pressurization system by setting wellhead hanging hardware 7 at the top of the multi-channel cable laying pipe 4.

[0042] Specifically, the design power of each stage of the drive motor 112 can be independently configured according to the load of its corresponding compressor unit 11 (i.e., the same or different), but all drive motors 112 must maintain strict phase synchronization. This requirement ensures that the rotation of each stage of the mixed-flow compressor impeller 113 maintains precise angular consistency, thereby enabling coordination and drive by the same frequency converter on the ground, ensuring the smooth operation and control efficiency of the entire booster system.

[0043] One specific implementation of the cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells described in this application is as follows.

[0044] This downhole booster system, through a cascade-type inclined flow bottom-hole booster pump 1 installed inside casing 2, a multi-channel cable pipe 4, and supporting components, constructs a novel downhole natural gas booster extraction method. The system establishes new pressure segments downhole: the first segment is the pressure drop from the formation to the inlet of the cascade-type inclined flow bottom-hole booster pump 1 (Pr-P1), and the second segment is the pressure drop from the outlet of the cascade-type inclined flow bottom-hole booster pump 1 to the wellhead (P1-P2). Here, Pr is the formation pressure, P1 is the outlet pressure of the cascade-type inclined flow bottom-hole booster pump 1, and P2 is the wellhead pressure.

[0045] With the well shut in, the downhole booster system is in pressure equilibrium, P2≈P1≈Pr, and the gas flow is static. When gas production begins, the cascade-type inclined flow bottomhole booster pump 1 starts operating, with its outlet pressure P1=Pr+ΔP (ΔP being the boost pressure value). At this point, P1 effectively replaces the original formation pressure Pr as the lifting power source. Because P1>Pr, the downhole booster system's ability to overcome wellbore flow resistance is significantly enhanced, thus enabling the lifting of natural gas that would otherwise be impossible to recover naturally to the wellhead.

[0046] When the cascade-type inclined flow bottom-hole booster pump 1 is in operation, a relative negative pressure is generated at its inlet end, which promotes the accumulation of formation natural gas towards the cascade-type inclined flow bottom-hole booster pump 1, thereby improving the gas permeability. This scheme is particularly suitable for gas wells with low gas reserves and low formation pressure.

[0047] As a key improvement in this embodiment, the inner diameter of the central gas channel of the multi-channel cable-laying pipe 4 is smaller than that of conventional oil production pipes. This small-diameter central gas channel has a smooth and continuous inner surface, and its gas resistance is only 1 / 2 to 2 / 3 of that of conventional oil pipes. Under the thrust of the cascade-type inclined flow bottom-hole booster pump 1, the gas velocity in the channel is high, the liquid carrying capacity is enhanced, and production stability is further guaranteed.

[0048] In a specific calculation and design case, for a low-production well with a depth of approximately 2500 meters and a formation pressure of 1.5 MPa (Pr), the design employs a 2400-meter-long multi-channel cable duct 4 (with a central gas channel inner diameter of 50 mm) and a cascade-type inclined flow bottom-hole booster pump 1 consisting of a 5-stage compressor unit 11 and a total pressure ratio of 1.5. This cascade-type inclined flow bottom-hole booster pump 1 is designed to operate at a speed of 25000-40000 r / min, with a matching drive motor 112 having a total power of 30 kW, and the gas is filtered through a sand-proof pipe 5.

[0049] Calculations show that to achieve a daily production of 7000 cubic meters and a wellhead pressure P2 of 0.8 MPa, the minimum bottomhole flowing pressure (Prpre) required for conventional tubing gas production is approximately 1.7-2.1 MPa. This embodiment, through downhole pressurization, achieves an effective bottomhole flowing pressure (Princreased) of 2.25 MPa (i.e., 1.5 MPa × 1.5). Since Princreased > Prpre, this demonstrates that the technical solution of this application has the capability to meet production requirements. Furthermore, the multi-channel cable-laying pipe 4 has lower gas resistance, enabling the system to achieve production enhancement targets more efficiently.

[0050] This application provides a bottom-hole electric high-speed booster method for oil and gas wells using non-metallic cable-laying pipes. The method employs a cascade-type bottom-hole electric high-speed booster pump used with the aforementioned oil and gas well non-metallic cable-laying pipes. The method includes the following steps:

[0051] S1: The cascade-type inclined flow bottom booster pump 1 and the multi-channel cable laying pipe 4 are lowered and fixed to a predetermined depth inside the casing 2 of the oil and gas well by means of the wellhead hanging hardware 7, wherein the centralizer 6 ensures that the multi-channel cable laying pipe 4 is centered inside the casing 2.

[0052] S2: The cable 9 in the cable channel of the multi-channel cable laying pipe 4 supplies power to the various levels of drive motors 112 and carrier sensor 3; at the same time, the carrier sensor 3 collects downhole formation parameters in real time and uses power line carrier communication technology to transmit the collected data to the ground control system through the same cable 9.

[0053] S3: Under the action of pressure difference, the formation natural gas is filtered by the sand-proof pipe string 5 installed at the air inlet of the cascade-type inclined flow bottom booster pump 1 and then sucked into the cascade-type inclined flow bottom booster pump 1.

[0054] S4: Start the drive motor 112 of each stage compressor unit 11 to drive the impeller 113 of the mixed flow compressor to rotate at high speed, with a speed range of 15,000 to 50,000 r / min; natural gas flows through each stage of the series compressor unit 11 in sequence and is compressed step by step under the guidance of the annular gas flow channel and the guide tail section 114, so that the total pressure ratio reaches 1.2 to 3.0, thereby obtaining a lifting pressure higher than the formation pressure at the gas outlet of the cascade mixed flow bottom booster pump 1.

[0055] S5: The pressurized high-pressure natural gas enters the central gas channel of the multi-channel cable pipe 4, which has an inner diameter smaller than that of the conventional oil production pipe. Driven by the lifting pressure, it moves toward the wellhead at a high flow rate, effectively overcoming flow resistance and hydrostatic pressure, and is lifted to the surface.

[0056] S6: The ground control system dynamically adjusts the speed and operating status of each stage of drive motor 112 based on the real-time downhole data transmitted by the carrier sensor 3, so as to achieve precise control of the downhole pressurization condition and optimized system operation.

[0057] It should be noted that the core of the pressurization method in this application lies in the organic combination of three major technical elements: "bottom hole cascade pressurization," "integrated power supply and communication," and "small-diameter high-speed lifting," forming an active and efficient downhole pressure management system. This method successfully transforms the natural depletion-type production of low-pressure, low-production wells described in the background technology into "active pressurization-type production with artificial intervention." By creating a new and higher bottom hole pressure to replace the original insufficient formation pressure, it overcomes the technical bottleneck of limited effectiveness and high cost of traditional processes in low-production wells.

[0058] The various embodiments in this specification are described in a progressive manner. For the same or similar parts between the various embodiments, please refer to each other. Each embodiment focuses on describing the differences from other embodiments.

[0059] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells, characterized in that, include: A cascade-type inclined flow bottom-hole booster pump (1) is housed in the casing (2) of an oil and gas well, and its inlet end is used to draw in natural gas from the bottom of the well. A carrier sensor (3) is installed at the air inlet of the cascaded inclined flow bottom booster pump (1) to collect downhole formation parameters in real time and transmit data through power line carrier communication. The lower end of the multi-channel cable laying pipe (4) is connected to the outlet end of the cascade-type inclined flow bottom booster pump (1), and the upper end extends to the wellhead; The cascaded inclined flow bottom-hole booster pump (1) includes at least two stages of compressor units (11), and the gas channels of each stage of the compressor units (11) are connected in series to form a continuous series booster gas path; the drive motors (112) of each stage of the compressor units (11) are connected by parallel circuits; the multi-channel cable pipe (4) has a composite channel structure, with a central gas pipe channel in the middle and at least one independent cable channel in the circumference; the inner diameter of the central gas pipe channel is smaller than the inner diameter of a conventional oil production pipe and is connected to the outlet end of the cascaded inclined flow bottom-hole booster pump (1); The cable (9) in the cable channel provides power to the various stages of the drive motor (112) of the parallel circuit and the carrier sensor (3), and constitutes the transmission medium for the power line carrier communication; The compressor unit (11) includes: The motor housing (111) has a sealed internal structure; The drive motor (112) is housed within the motor housing (111); The impeller (113) of the mixed-flow compressor is connected to the output end of the drive motor (112) and rotatably connected to the inlet end of the motor housing (111); An annular air flow channel is formed between the outer wall of the motor housing (111) and the inner wall of the sleeve (2); The sleeve (2) is provided with an electrical interface that communicates with the cable channel of the multi-channel cable laying pipe (4) for accessing power and carrier signals; The outer wall of the motor housing (111) is provided with a spiral oblique flow air passage groove (1111) along its axial direction. The annular airflow channel is formed between the spiral oblique flow channel groove (1111) and the inner wall of the sleeve (2); The total pressure ratio of the cascaded inclined flow bottom booster pump (1) is 1.2 to 3.0, and the speed range of each compressor unit (11) is 15,000 to 50,000 r / min; the design power of each stage drive motor (112) is independently configured according to the load of its corresponding compressor unit (11); The power supply line for the parallel drive motor (112) is provided by a 3-660V plug-in cable and connected to the drive motor (112) via a plug-in power terminal (10).

2. The cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells according to claim 1, characterized in that, The compressor unit (11) also includes a guide tail section (114) disposed at the outlet end of the motor housing (111); The guide tail section (114) is configured to converge the gas passage cross section at its outlet end to a preset size, which matches the intake requirements of the slant compressor impeller (113) of the next-stage compressor unit (11).

3. The cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells according to claim 1, characterized in that, The drive motor (112) is a permanent magnet synchronous high-speed motor.

4. The cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells according to claim 1, characterized in that, It also includes sand-proof pipe strings (5); The sand-proof pipe string (5) is installed at the air inlet of the cascade-type inclined flow bottom booster pump (1) and is used to filter solid impurities in the formation.

5. The cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells according to claim 1, characterized in that, It also includes a centralizer (6); The straightener (6) is disposed on the outer wall of the multi-channel cable laying pipe (4) to center the multi-channel cable laying pipe (4) within the sleeve (2).

6. The cascade bottom-hole electric high-speed booster pump for use with non-metallic cable-laying pipes in oil and gas wells according to claim 1, characterized in that, It also includes wellhead hanging hardware (7); The wellhead hanging hardware (7) is installed on the top of the multi-channel cable laying pipe (4).

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