Double-circulation-path submersible motor system with gradient temperature detection and fault pre-judgment functions
By using the gradient temperature detection and fault prediction functions of the dual-circulation submersible motor system, the problems of low heat dissipation efficiency and frequent faults of high-temperature submersible motors have been solved, achieving efficient heat dissipation and fault prediction, and reducing the risks and costs of downhole operations.
Patent Information
- Application Number
- CN202511244158.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-02
- Publication Date
- 2025-11-21
AI Technical Summary
In existing heavy oil extraction, high-temperature submersible motors have low heat dissipation efficiency, frequent failures, and lack effective fault prediction functions, resulting in frequent well workover operations, increased costs, and the risk of secondary damage.
The system employs a dual-circulation submersible motor system, combined with gradient temperature detection and fault prediction functions. It monitors temperature changes through Tesla valve channel heat dissipation and fiber optic temperature probes, and combines the inverter's preset fault prediction algorithm to achieve real-time monitoring and prediction in high-temperature environments.
It significantly improves heat dissipation efficiency, reduces the probability of failure, extends equipment life, enhances the safety and reliability of downhole operations, and reduces the need for well workover operations.
Smart Images
Figure CN120999974A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of petroleum extraction technology, and more specifically, it relates to a dual-circulation submersible motor system with gradient temperature detection and fault prediction functions. Background Technology
[0002] Heavy oil injection-production technology is one of the important technical means for heavy oil extraction, but existing processes have significant technical bottlenecks in the injection-production conversion process. Due to the high viscosity and poor fluidity of heavy oil, injection-production conversion usually requires well workover operations, including replacing injection-production tubing and adjusting downhole equipment. These workover operations not only require the suspension of production activities, but also the use of workover equipment and professional personnel, resulting in a significant increase in operating costs and a longer operation cycle. Furthermore, frequent workover operations may cause secondary damage to the oil reservoir, affecting the recovery rate.
[0003] In high-temperature electric pump injection and production processes, existing submersible motors typically employ a single circulation path, resulting in low heat dissipation efficiency. Especially in high-temperature environments, the motors exhibit poor reliability and are prone to failure due to overheating, failing to meet the requirements for long-term stable operation under high-temperature conditions. Furthermore, existing submersible motors lack effective fault prediction capabilities, leading to frequent sudden failures, further increasing the demand and cost of well workover operations. Summary of the Invention
[0004] This invention aims to at least solve one of the technical problems existing in the prior art. To this end, this invention provides a dual-circulation submersible motor system with gradient temperature detection and fault prediction functions, aiming to achieve pre-assessment of the operating conditions of high-temperature submersible motors and predict unit failure risks in advance.
[0005] To achieve the above objectives, the present invention adopts the following technical solution: a dual-circulation submersible motor system with gradient temperature detection and fault prediction functions, including a motor body, a heat sink, an optical fiber temperature probe, an optical fiber demodulator, a motor oil tank, a reference motor, a heating resistor, a PLC, a current sensor, a voltage sensor, and an insulation DC resistance tester. The motor body is installed inside the oil well to simulate the actual situation downhole. One or more heat dissipation blocks are provided on the outer wall of the motor body. The heat dissipation blocks have a Tesla valve structure inside. Multiple temperature measuring points are provided at different positions on the outer wall and inside of the motor body. Each temperature measuring point is equipped with a fiber optic temperature measuring probe to monitor the temperature field around and inside the motor body. The fiber optic demodulator is installed at the wellhead of the oil well and connected to the fiber optic temperature probe via the motor's main power cable. At the same time, the fiber optic demodulator is connected to the PLC to transmit the temperature rise of various positions of the motor body detected by the fiber optic temperature probe to the PLC. The control motor is placed in the motor oil sump used to simulate the downhole environment. Heating resistors are installed on the outer wall and inside of the control motor at the same locations as the temperature measuring points on the motor body. These heating resistors are connected to the PLC via a frequency converter. The PLC controls the heating resistors to heat to a specified temperature through the frequency converter, creating a simulated temperature field around and inside the control motor that is identical to that of the motor body. This facilitates direct observation of the control motor's operation under high temperatures in a land-based laboratory. A current sensor, a voltage sensor, and an insulation DC resistance tester are installed at the output position of the control motor to monitor the current, voltage, and insulation data of the control motor in real time. This allows the control motor to be alerted to potential faults when it experiences large current fluctuations, overload, undervoltage, or insulation degradation.
[0006] Preferably, the Tesla valve structure has multiple flow holes inside the heat sink for fluid to pass through, with the inlet holes located at the upper end of the heat sink. Utilizing the Tesla valve's rapid forward conduction, the fluid flow rate outside the motor body is accelerated. At the same time, utilizing the Tesla valve's slow reverse conduction, turbulence of the high-temperature well fluid outside the motor body is avoided, forming stable upper and lower flow channels that complement the heat dissipation flow channels inside the motor body, thus forming a dual flow channel.
[0007] Preferably, the motor body includes: a base for fixing the motor body; a first bellows connected to the motor body to ensure the motor oil can breathe freely during temperature rise and fall; an oil injection valve for injecting motor oil; a rotor assembly and a stator assembly disposed inside the motor body; a motor head installed below the rotor assembly and stator assembly for providing cable and lead wire connections; a lead wire connector disposed outside the motor head; a settling chamber shell disposed above the motor head, with a settling shaft guard tube disposed inside the settling chamber shell; a breather pipe disposed inside the settling chamber shell, and an overflow valve disposed on the breather pipe for releasing oil pressure after the motor body temperature rises; a second bellows for controlling the breathing of the motor oil and, together with the overflow valve, controlling the oil pressure; a connector connected to the second bellows; a mechanical seal disposed inside the connector for preventing liquid leakage and ensuring the internal sealing of the motor body; and a transport cap located at the top of the motor body for providing protection during transport of the motor body.
[0008] The present invention has the following advantages due to the adoption of the above technical solutions: This invention achieves dual-path circulation for a high-temperature submersible motor (SLM) through a Tesla valve, significantly improving the motor's internal heat dissipation efficiency and fluid distribution uniformity. Simultaneously, combined with downhole gradient temperature detection technology, it enables real-time monitoring of temperature changes during SLM operation, providing accurate data support for subsequent fault prediction. Furthermore, this invention incorporates a fault prediction algorithm pre-set in the frequency converter, analyzing the dynamic changes in SLM operating parameters to predict potential fault risks in advance. This invention not only provides a comprehensive pre-assessment of SLM operating conditions but also effectively reduces the probability of sudden failures, extends equipment lifespan, and provides strong technical support for the safety and reliability of downhole operations. Attached Figure Description
[0009] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Throughout the drawings, the same reference numerals denote the same parts. In the drawings: Figure 1 This is a structural block diagram of a dual-circulation submersible motor system provided in an embodiment of the present invention; Figure 2 This is a schematic diagram of the structure of a motor body provided in an embodiment of the present invention.
[0010] The labels for the attached figures are as follows: 1-Motor body; 2-Heat sink; 3-Fiber optic temperature probe; 4-Fiber optic demodulator; 5-Motor oil bath; 6-Reference motor; 7-Heating resistor; 8-PLC; 9-Current sensor; 10-Voltage sensor; 11-Insulation DC resistance tester; 12-Frequency converter; 101-Base; 102-First bellows; 103-Oil injection valve; 104-Rotor assembly; 105-Stator assembly; 106-Motor head; 107-Lead wire connector; 108-Settling chamber shell; 109-Settling shaft protector tube; 110-Breathing tube; 111-Overflow valve; 112-Second bellows; 113-Connector; 114-Mechanical seal; 115-Transport cap. Detailed Implementation
[0011] To make the objectives, technical solutions, and advantages of the present invention clearer, specific embodiments of the present invention will be further described below with reference to the accompanying drawings. Although exemplary embodiments of the present invention are shown in the drawings, it should be understood that the present invention can be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present invention and to fully convey the scope of the present invention to those skilled in the art.
[0012] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" 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 this invention and simplifying the description, and are not intended to 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 invention.
[0013] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.
[0014] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0015] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0016] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0017] This invention provides a dual-circulation submersible motor system with gradient temperature detection and fault prediction functions. The system includes a motor body, a Tesla valve heat sink, a fiber optic temperature probe, a fiber optic demodulator, a motor oil sump, a control motor, a resistance temperature detector (RTD), a PLC, a current sensor, a voltage sensor, and an insulation DC resistance tester. This invention achieves dual-circuit circulation for the submersible motor through a Tesla valve channel. Through downhole gradient temperature detection technology and a fault prediction algorithm preset in the frequency converter, it enables pre-assessment of the operating conditions of high-temperature units and early prediction of unit failure risks. This invention not only provides a comprehensive pre-assessment of the submersible motor's operating conditions but also effectively reduces the probability of sudden failures, extends equipment lifespan, and provides strong technical support for the safety and reliability of downhole operations.
[0018] The following is a detailed description of the dual-circulation submersible motor system with gradient temperature detection and fault prediction functions provided in the embodiments of the present invention, with reference to the accompanying drawings.
[0019] Please see Figure 1The dual-circulation submersible motor system with gradient temperature detection and fault prediction functions provided in this embodiment includes a motor body 1, a heat sink 2, a fiber optic temperature probe 3, a fiber optic demodulator 4, a motor oil tank 5, a reference motor 6, a heating resistor 7, a PLC 8, a current sensor 9, a voltage sensor 10, and an insulation DC resistance tester 11. The motor body 1 is installed inside the oil well to simulate actual downhole conditions. One or more heat sinks 2 are installed on the outer wall of the motor body 1. The heat sink 2 has a Tesla valve structure with multiple flow holes for fluid passage. The inflow holes are located at the upper end of the heat sink 2. Utilizing the rapid forward flow characteristic of the Tesla valve, the fluid flow rate outside the motor body 1 is accelerated. Simultaneously, utilizing the slow reverse flow characteristic of the Tesla valve, turbulence of the high-temperature well fluid outside the motor body 1 is avoided, forming stable upper and lower flow channels that complement the internal heat dissipation channels of the motor body 1, creating a dual-channel system. Multiple temperature measuring points are installed at different locations on the outer wall and inside the motor body 1. Each temperature measuring point is equipped with a fiber optic temperature probe 3 to monitor the temperature field around and inside the motor body 1. A fiber optic demodulator 4 is installed at the wellhead and connected to the fiber optic temperature probe 3 via the motor's main power cable. The fiber optic demodulator 4 is also connected to a PLC 8 to transmit the fiber optic signals. Temperature rise detected by temperature probe 3 at various locations on motor body 1 is transmitted to PLC 8. A control motor 6 is placed in an oil bath 5 simulating the downhole environment. Heating resistors 7 are installed on the outer wall and inside of the control motor 6 at the same locations as the temperature measurement points on motor body 1. Heating resistors 7 are connected to PLC 8 via frequency converter 12. PLC 8 controls the heating resistors 7 to reach a specified temperature (i.e., the same temperature as the measurement point) via frequency converter 12, creating a simulated temperature field around and inside the control motor 6 identical to that of motor body 1. This facilitates direct observation of the operation of the control motor 6 under high temperatures in a land-based laboratory. A current sensor 9, a voltage sensor 10, and an insulation DC resistance tester 11 are installed at the output position of the control motor 6 to monitor the current, voltage, and insulation data of the control motor 6 in real time. This allows the control motor 6 to detect faults such as large current fluctuations, overload, undervoltage, and insulation degradation, indicating a potential fault risk in motor body 1.
[0020] Please see Figure 2The motor body 1 includes: a base 101 for fixing the motor body 1; a first bellows 102 connected to the motor body 1 to ensure that the motor oil can breathe freely during temperature rise and fall; an oil injection valve 103 for injecting motor oil; a rotor assembly 104 and a stator assembly 105 disposed inside the motor body 1; a motor head 106 installed below the rotor assembly 104 and the stator assembly 105 for providing cable and lead wire connections; a lead wire connector 107 disposed outside the motor head 106; and a settling chamber housing 108 disposed above the motor head 106, with a settling shaft protector tube disposed inside the settling chamber housing 108. 109; Breathing tube 110, located inside the settling chamber shell 108, and equipped with an overflow valve 111, used to release oil pressure after the motor body 1 heats up; Second bellows 112, used to control the motor oil breathing, and together with the overflow valve 111, to control the oil pressure; Connector 113, connected to the second bellows 112; Mechanical seal 114, located inside the connector 113, used to prevent liquid leakage and ensure the internal sealing of the motor body 1; Transport cap 115, located at the top of the motor body 1, used to provide protection during the transport of the motor body 1.
[0021] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. 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. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.
Claims
1. A dual-circulation submersible motor system with gradient temperature detection and fault prediction functions, characterized in that, Includes motor body, heat sink, fiber optic temperature probe, fiber optic demodulator, motor oil bath, reference motor, heating resistor, PLC, current sensor, voltage sensor, and insulation DC resistance tester; The motor body is installed inside the oil well to simulate the actual situation downhole. One or more heat dissipation blocks are provided on the outer wall of the motor body. The heat dissipation blocks have a Tesla valve structure inside. Multiple temperature measuring points are provided at different positions on the outer wall and inside of the motor body. Each temperature measuring point is equipped with a fiber optic temperature measuring probe to monitor the temperature field around and inside the motor body. The fiber optic demodulator is installed at the wellhead of the oil well and connected to the fiber optic temperature probe via the motor's main power cable. At the same time, the fiber optic demodulator is connected to the PLC to transmit the temperature rise of various positions of the motor body detected by the fiber optic temperature probe to the PLC. The control motor is placed in the motor oil sump used to simulate the downhole environment. Heating resistors are installed on the outer wall and inside of the control motor at the same locations as the temperature measuring points on the motor body. These heating resistors are connected to the PLC via a frequency converter. The PLC controls the heating resistors to heat to a specified temperature through the frequency converter, creating a simulated temperature field around and inside the control motor that is identical to that of the motor body. This facilitates direct observation of the control motor's operation under high temperatures in a land-based laboratory. A current sensor, a voltage sensor, and an insulation DC resistance tester are installed at the output position of the control motor to monitor the current, voltage, and insulation data of the control motor in real time. This allows the control motor to be alerted to potential faults when it experiences large current fluctuations, overload, undervoltage, or insulation degradation.
2. The dual-circulation submersible motor system according to claim 1, characterized in that, The Tesla valve structure has multiple flow holes inside the heat sink for fluid to pass through, with the inlet holes located at the upper end of the heat sink. Utilizing the Tesla valve's rapid forward conduction, it accelerates the fluid flow rate outside the motor body. At the same time, utilizing the Tesla valve's slow reverse conduction, it prevents turbulence of the high-temperature well fluid outside the motor body, forming a stable upper and lower flow channel. This complements the heat dissipation flow channel inside the motor body, forming a dual flow channel.
3. The dual-circulation submersible motor system according to claim 1, characterized in that, The motor body includes: The base is used to fix the motor body; The first bellows is connected to the motor body to ensure that the motor oil can breathe freely during temperature rise and fall. The oil injection valve is used to inject motor oil; The rotor assembly and stator assembly are located inside the motor body; The motor head, mounted below the rotor assembly and stator assembly, is used to provide cable and lead connections; A lead wire connector is disposed outside the motor head; A settling chamber housing is disposed above the motor head, and a settling shaft protector tube is disposed inside the settling chamber housing; A breathing tube is installed inside the outer shell of the settling chamber, and an overflow valve is provided on the breathing tube to release oil pressure after the motor body temperature rises. The second bellows is used to control the breathing of the motor oil and, together with the overflow valve, plays the role of controlling the oil pressure. The connector is used to connect to the second bellows. A mechanical seal is installed inside the connector to prevent liquid leakage and ensure the internal sealing of the motor body; A transport cap, located at the very top of the motor body, is used to provide protection during the transport of the motor body.