Sectional type electric heating assisted thickened oil recovery system and method

Abstract

The invention belongs to the technical field of oil exploitation, and particularly discloses a sectional type electric heating auxiliary thickened oil exploitation system and method.The system comprises a power supply station, a voltage transformation power regulation cabinet, a junction box, an injection and production pry, a power supply section cable, a cable connector, a wellhead, a production sleeve, a main pipe, an auxiliary pipe, a heating section cable, a hanger and a screen pipe, the production sleeve is connected with a wellhead, the hanger is located in the production sleeve, the screen pipe is connected with the production sleeve through the hanger, the main pipe is located in the production sleeve, the auxiliary pipe is located in the production sleeve and the screen pipe, and the heating section cable is located in the auxiliary pipe. The heating section cable is composed of a central supporting line, a plurality of heating modules, a plurality of module spacing layers and a metal sheath from inside to outside, the plurality of heating modules are uniformly connected to the central supporting line in series, the plurality of module spacing layers are located between two adjacent heating modules, and each heating module is integrated with an SIC power switch. And the heating section cable is connected with the power supply section cable through a cable joint.

Description

Technical Field

[0001] This invention relates to the field of petroleum extraction technology, specifically to a segmented electrically heated assisted heavy oil extraction system and method. Background Technology

[0002] Oil is typically found deep underground in porous and permeable reservoir formations, sealed by impermeable caprocks. The principle of oil extraction is to gradually release reservoir energy and extract crude oil through staged technologies. First, primary recovery utilizes the natural energy of the formation to propel crude oil to the surface; this stage typically recovers 5%-20% of the original geological reserves. As natural energy is depleted, secondary recovery replenishes formation pressure through water or gas injection, creating an artificially driven system that increases the recovery rate to 30%-40%. When the reservoir enters a high water-cut phase, tertiary recovery employs technologies such as chemical flooding (e.g., polymers, surfactants), thermal flooding (steam injection), and miscible flooding. By reducing oil-water interfacial tension and improving crude oil fluidity, the recovery rate can be further enhanced, potentially reaching over 50%.

[0003] Downhole electric heating technology, as an important engineering means to address the fluidity problems of heavy oil with high viscosity and wax deposition, mainly relies on mature methods such as electric heating rods and integrated heaters. Its core principle is to directly convert electrical energy into heat energy, and then use heating elements arranged in the wellbore to raise the temperature of the target formation and the surrounding fluid. This aims to effectively reduce crude oil viscosity, melt deposited paraffin, or improve near-wellbore seepage conditions, thereby maintaining or restoring oil well productivity.

[0004] However, existing electric heating systems have a fundamental limitation: they cannot achieve precise, segmented, and independent electric heating control along the production wellbore. Current methods typically only provide uniform heating across the entire heating section, or the heating power is monotonically distributed along the wellbore length, lacking fine-tuning. This extensive heating approach cannot provide differentiated, independently controllable temperature fields for different depths and properties in heterogeneous reservoirs. This results in non-target sections being ineffectively heated, wasting significant energy, while target sections may be underheated or overheated, hindering efficient thermal energy utilization and precise improvements in the extraction of complex reservoirs. Summary of the Invention

[0005] The purpose of this invention is to provide a segmented electric heating-assisted heavy oil extraction system and method to solve the problems of existing cable heating modes being unable to provide targeted heating, resulting in ineffective heating of non-target layers and insufficient or excessive heating of target layers, which restricts the efficiency of thermal energy utilization and the extraction effect of complex oil reservoirs.

[0006] To achieve the above objectives, the basic solution provided by this invention is as follows: a segmented electrically heated assisted heavy oil extraction system, comprising an above-ground power supply station, a transformer control cabinet, a junction box, an injection-production skid, a power supply section cable, a cable connector, and a wellhead; and underground components including a production casing, main pipe, auxiliary pipe, heating section cable, a hanger, and a screen pipe. The power supply station is electrically connected to the transformer control cabinet, which is also electrically connected to the junction box and the injection-production skid. The power supply section cable is connected to the transformer control cabinet, the production casing is connected to the wellhead, and the hanger is located underground. Inside the production casing, the screen tube is connected to the production casing via a hanger. The main tube is located inside the production casing, the secondary tube is located inside both the production casing and the screen tube, and the heating section cable is located inside the secondary tube. The heating section cable consists of a central support line, several heating modules, several module spacers, and a metal sheath from the inside out. Several heating modules are evenly connected in series on the central support line, and several module spacers are located between two adjacent heating modules. Each heating module integrates a SiC power switch. The heating section cable and the power supply section cable are connected via a cable connector.

[0007] The working principle of this invention is as follows: A power station provides high-voltage electrical energy, which is converted to a suitable voltage and precisely regulated by a transformer and power control cabinet. One path is transmitted via a power supply cable to a junction box, and then connected via a cable connector to a heating section cable located inside the downhole auxiliary pipe. The other path directly powers the injection-production skid. The heating section cable is its core component. Its central support line contains heating modules integrated with SiC power switches, which generate Joule heat through the high-speed switching action of the SiC devices after being energized. This heat is efficiently transferred to the auxiliary pipe and its surrounding environment through a metal sheath, directly heating the heavy oil in the reservoir and significantly reducing its viscosity. Simultaneously, the injection-production skid uses electrical energy to heat the fluid into steam and inject it into the oil layer to assist in oil displacement, or directly pumps the heated and viscosity-reduced heavy oil to the surface.

[0008] The beneficial effects of this invention are as follows: The heating module using SiC power switches in this system is a key breakthrough. SiC material is resistant to high temperatures, has a high switching frequency, and low losses, enabling the heating section to generate high-temperature heat efficiently and stably in the high-temperature environment downhole. It also allows for precise power and temperature zone control, improving thermal efficiency and heating uniformity. The modular series design, combined with module spacers and a metal sheath, ensures both the reliability of electrical connections and heat dissipation, while providing robust mechanical protection and extending cable life. Direct heating of the oil reservoir effectively reduces the viscosity of deep heavy oil, improving fluidity and recovery rate. The integrated electrothermal design avoids the high energy consumption and heat loss of traditional steam boilers, resulting in a relatively simplified system structure and more environmentally friendly and energy-efficient operation. This system significantly improves the economics and technical feasibility of heavy oil extraction, and is particularly suitable for deep, extra-heavy oil reservoirs or reservoirs where steam drive is ineffective.

[0009] Option 2, a preferred option of the basic scheme, involves a transformer control cabinet connected to an air supply unit. This unit includes a ground-level air collection assembly and underground transmission ducts. The ground-level air collection assembly consists of a fan, a collection duct, an air supply duct, and a sleeve. The underground transmission duct connects L-shaped and straight pipes. The collection duct is sealed to the fan outlet and also connects to the straight pipe. The horizontal sections of the straight pipe and L-shaped pipe are detachably connected. Several baffles are installed inside the straight pipe. The vertical end of the L-shaped pipe above ground connects to the air supply duct, which is sealed to the sleeve. An air regulating chamber is located at the bottom of the transformer control cabinet, and the sleeve connects to this chamber. This underground ducting method utilizes the surrounding environment for air cooling. The duct material uses materials with high thermal conductivity, such as aluminum. The baffles inside the straight pipe prevent fine dust from entering through the air inlet, and the detachable design facilitates the removal of the straight pipe from underground for cleaning.

[0010] Option 3, an optimal choice from Option 2, involves installing a dust cover around the transformer control cabinet. This dust cover has several ventilation holes, each equipped with a filter. A door panel is located on one side of the dust cover. The filter-equipped ventilation holes allow for controlled airflow between the inside and outside of the dust cover. This ensures efficient heat dissipation for the transformer control cabinet while forming a physical barrier to prevent the intrusion of external dust, oil, and foreign objects. Combined with the openable door panel, it balances equipment protection with ease of maintenance, improving the operational reliability of core electrical equipment in the harsh environment of the oilfield.

[0011] Option 4, a preferred option of Option 2, features a one-way bearing on the fan shaft. A pressure collection box is fixedly connected to the fan shaft. A first bevel gear is fixed to the outer ring of the one-way bearing. A second bevel gear is located inside the pressure collection box, meshing with the first bevel gear. A connecting rod is fixed to the second bevel gear, and several blades are mounted on the connecting rod. Both the connecting rod and the blades are located within the pressure collection box. A pressure discharge pipe is connected to one side of the pressure collection box, with its free end located at the cable connector. Utilizing the rotational kinetic energy of the fan shaft, the blades within the pressure collection box are driven by the one-way bearing, bevel gear one, and bevel gear two to generate a directional pressurized airflow. This airflow is then precisely blown through the pressure discharge pipe to the cable connector, achieving efficient active cooling and dust protection without the need for additional power.

[0012] Option 5, a preferred option of Option 4, involves installing a mounting bracket on one side of the cable connector, with an infrared thermal imager mounted on the bracket. The mounting bracket precisely positions the infrared thermal imager on the side of the cable connector, enabling non-contact, real-time dynamic monitoring of its surface temperature field, avoiding installation damage and response delays associated with contact temperature measurement.

[0013] Option 6, which is the preferred option of Option 5, is equipped with several thermocouples on the main pipe, screen pipe, and heating section cable. The transformer power control cabinet, power supply section cable, cable joint, SiC power switch, injection and extraction skid, fan, and infrared thermal imager are all connected to the PLC controller.

[0014] Option 7, a segmented electrically heated assisted heavy oil extraction method, includes the following steps: S1: Inject 80-120℃ saturated water into the reservoir through vertical wells, controlling the saturated water volume at 20-27t and controlling the injection pressure at 70%-90% of the formation fracture pressure; S2: Synchronously start the cable of the built-in heating section of the auxiliary pipe, use segmented temperature control technology to heat the saturated water, use thermocouples to monitor the downhole temperature, control the temperature of the vertical section at 150-250℃, control the temperature of the horizontal section at 250-350℃, and control the temperature gradient of the heating section within ±2℃. S3: Saturated water is heated to form steam, which enters the oil layer for preheating, maintaining the wellbore temperature at 100-150℃; S4: Inject saturated steam into the horizontal well, with the temperature controlled at 240-320℃ and the injection rate at 8-15 m³ / h. Inject nitrogen into the vertical well to assist in volume expansion, with the nitrogen injection volume accounting for 5-15% of the steam volume. S5: The staff closes the wellhead and begins the well shut-in operation, controlling the well shut-in time to 20-60 days. During this period, thermocouples are used to monitor the downhole temperature and maintain the reservoir temperature at 150-200℃. S6: After the well is shut down, start production in the horizontal well, monitor the bottom hole pressure in real time, and control the saturated steam pressure to 70-90% of the formation fracture pressure. After the reservoir steam replaces the liquid, it is squeezed into the screen pipe and then enters the production casing from the screen pipe and is extracted by the main pump.

[0015] Option 8 is an optimal choice from Option 7. The segmented temperature control technology in step S2 is as follows: Vertical section: The temperature for vertical depths of 10-60m is controlled at 150±5℃, the temperature for vertical depths of 61-110m is controlled at 200±5℃, and the temperature for vertical depths of 111-180m is controlled at 245±5℃. Horizontal section: The temperature at a distance of 10-130m from the vertical section is controlled at 260±5℃, the temperature at a distance of 131-240m from the vertical section is controlled at 300±5℃, and the temperature at a distance of 240-380m from the vertical section is controlled at 345±5℃.

[0016] Option 9, which is the preferred option of Option 8, controls the dryness of the injected steam at 75-85%.

[0017] Option 10, a preferred option to Option 9, involves using a non-stop fluid replacement method by adjusting the nozzles during extraction. The specific details are as follows: When the injection-to-sumption ratio is <0.9 or the pump inlet pressure is > saturated steam pressure, gradually reduce the nozzle size by 0.3-0.7 mm each time. When the temperature at the end of the horizontal section suddenly rises by 20°C, gradually enlarge the nozzle by 0.5-1mm each time. Attached Figure Description

[0018] Figure 1 This is a process diagram of a segmented electrically heated assisted heavy oil extraction system and method according to the present invention; Figure 2 This is a downhole structure schematic diagram of a segmented electrically heated assisted heavy oil extraction system and method according to the present invention; Figure 3 This is a perspective view of the dust cover and air supply unit in a segmented electrically heated assisted heavy oil extraction system and method of the present invention. Figure 4 yes Figure 3 Enlarged view of point A in the middle; Figure 5 yes Figure 3 A 3D view with the dust cover removed; Figure 6 This is a perspective view of the air regulating chamber in a segmented electrically heated assisted heavy oil extraction system and method of the present invention; Figure 7 This is a schematic diagram of the straight pipe and the diverter plate in a segmented electrically heated assisted heavy oil extraction system and method of the present invention; Figure 8 This is a three-dimensional view of the wellhead, power supply cable, heating cable, cable connector, and infrared thermal imager in a segmented electric heating assisted heavy oil extraction system and method according to the present invention. Figure 9 This is a perspective view of a segmented electrically heated assisted heavy oil extraction system and method of the present invention, in which the blower is without the pressure collection box; Figure 10 yes Figure 9 Enlarged view of point B in the middle; Figure 11 This is a schematic diagram of the internal structure of the heating section cable in a segmented electrically heated assisted heavy oil extraction system and method of the present invention. Detailed Implementation

[0019] The present invention will be further described in detail below through specific embodiments: The reference numerals in the accompanying drawings include: 1. Power supply station, 2. Transformer control cabinet, 3. Junction box, 4. Injection / production skid, 5. Power supply section cable, 6. Cable joint, 7. Wellhead, 8. Production casing, 9. Main pipe, 10. Secondary pipe, 11. Heating section cable, 111. Central support line, 112. Heating module, 113. Module spacer layer, 114. Metal sheath, 115. SiC power switch, 12. Air supply unit, 121. Fan, 122. Air collection unit. 123. Air supply duct, 124. Pipe sleeve, 125. L-shaped pipe, 126. Straight pipe, 127. Diverter plate, 13. Screen pipe, 14. Dust cover, 15. Ventilation hole, 16. Filter screen, 17. Door panel, 18. One-way bearing, 19. Pressure collection box, 20. Bevel gear one, 21. Bevel gear two, 22. Connecting rod, 23. Blade, 24. Pressure discharge pipe, 25. Fixing bracket, 26. Infrared thermal imager, 27. Thermocouple, 28. Hanger, 29. Air regulating chamber.

[0020] Example 1 The implementation examples are basically as follows Figures 1 to 11The diagram shows a segmented electrically heated assisted heavy oil extraction system, comprising a power station 1, a transformer control cabinet 2, a junction box 3, an injection / production skid 4, a power supply cable 5, a cable connector 6, and a wellhead 7 located above ground; and a production casing 8, a main pipe 9, a secondary pipe 10, a heating section cable 11, a hanger 28, and a screen pipe 13 located underground. The power station 1 is electrically connected to the transformer control cabinet 2, which is also electrically connected to the junction box 3 and the injection / production skid 4. The power supply cable 5 is connected to the transformer control cabinet 2. The production casing 8 is connected to the wellhead 7. The hanger 28 is located inside the production casing 8. The screen pipe 13 is connected to the production casing 8 via the hanger 28. The main pipe 9 is located inside the production casing 8, and the secondary pipe 10 is located between the production casing 8 and the wellhead 7. Inside the screen tube 13, the heating section cable 11 is located inside the secondary tube 10. The heating section cable 11 consists of a central support line 111, several heating modules 112, several module spacers 113, and a metal sheath 114 from the inside out. The heating modules 112 are evenly connected in series on the central support line 111. The module spacers 113 are located between two adjacent heating modules 112. Each heating module 112 integrates a SiC power switch 115. The heating section cable 11 is connected to the power supply section cable 5 through a cable connector 6. The transformer power control cabinet 2 is connected to an air supply unit 12. The air supply unit 12 includes a ground air collection assembly and an underground transmission pipe. The ground air collection assembly consists of a fan 121, an air collection pipe 122, and a power supply... The system consists of duct 123 and sleeve 124. The underground transmission pipeline is connected by an L-shaped pipe 125 and a straight pipe 126. The collecting duct 122 is sealed to the outlet of the fan 121. The collecting duct 122 is connected to the straight pipe 126. The straight pipe 126 is detachably connected to the horizontal section of the L-shaped pipe 125. Several diverter plates 127 are installed inside the straight pipe 126. One end of the vertical section of the L-shaped pipe 125, located above ground, is connected to the supply duct 123. The supply duct 123 is sealed to the sleeve 124. The transformer control cabinet 2 has an air regulating chamber 29 at its bottom, and the sleeve 124 is connected to the air regulating chamber 29. A dust cover 14 is installed outside the transformer control cabinet 2. The dust cover 14 has several ventilation holes 15, and each ventilation hole 15 is equipped with a filter screen 16. One side of the dust cover 14... A door panel 17 is provided on the side. A one-way bearing 18 is provided on the shaft of the fan 121. A pressure collecting box 19 is fixedly passed through the shaft of the fan 121. A bevel gear 20 is fixedly connected to the outer ring of the one-way bearing 18. A bevel gear 21 is provided inside the pressure collecting box 19. The bevel gear 20 meshes with the bevel gear 21. A connecting rod 22 is fixedly connected to the bevel gear 21. Several blades 23 are provided on the connecting rod 22. The connecting rod 22 and the blades 23 are all located inside the pressure collecting box 19. A pressure discharge pipe 24 is connected to one side of the pressure collecting box 19. The free end of the pressure discharge pipe 24 is located at the cable joint 6. A fixing frame 25 is provided on one side of the cable joint 6. An infrared thermal imager 26 is provided on the fixing frame 25. Several thermocouples 27 are provided on the main pipe 9, the screen pipe 13, and the heating section cable 11.Transformer control cabinet 2, power supply cable 5, cable connector 6, SiC power switch 115, injection / mining skid 4, fan 121, and infrared thermal imager 26 are all connected to the PLC controller.

[0021] The implementation method of this embodiment is as follows: Power station 1 transmits high-voltage electrical energy to transformer power control cabinet 2. After voltage regulation and power adjustment, transformer power control cabinet 2 divides the power into two paths: one path transmits the power to junction box 3 via power supply section cable 5, and then connects to heating section cable 11 in downhole auxiliary pipe 10 via cable connector 6; the other path directly supplies power to injection and production skid 4 to drive injection and production operations. The core of heating section cable 11 consists of multiple heating modules 112 connected in series by central support line 111. Each module integrates SiC power switch 115. After being powered on, Joule heat is generated through high-frequency switching, and the heavy oil around screen pipe 13 is evenly heated through metal sheath 114 to reduce its viscosity. At the same time, the air supply unit 12 starts: the fan 121 rotates forward, and the airflow is delivered to the air supply duct 123 through the air collection duct 122, the straight duct 126 and the L-shaped duct 125. Finally, it is injected into the air regulating cavity 29 at the bottom of the transformer power regulating cabinet 2 through the pipe sleeve 124 for forced heat dissipation. When the fan blows air, the diverter plate 127 in the straight duct 126 further resists the sand and dust, ensuring that there are no impurities in the air blown into the transformer power regulating cabinet 2. After the air is blown and cooled for a period of time, the ground part of the straight duct 126 is twisted in the opposite direction to disassemble it and clean the sand and dust inside. After cleaning, the straight duct 126 is inserted into the ground and tightened in the forward direction. In addition, the infrared thermal imager 26 monitors the temperature of the cable joint 6 in real time. When the temperature is ≥65℃, the blower 121 is automatically reversed. The one-way bearing 18 on the shaft of the blower 121 drives the first bevel gear 20 to drive the second bevel gear 21, causing the connecting rod 22 and blades 23 in the pressure collecting box 19 to rotate and generate directional airflow. This airflow is then blown through the pressure discharge pipe 24 to cool and prevent dust from entering the cable joint 6. When the temperature is <50℃, the blower 121 resumes forward rotation. Thermocouples 27 on the main pipe 9, screen pipe 13, and heating section cable 11 collect downhole temperature data. All information is synchronously connected to the PLC controller along with the blower 121, injection and production skid 4, SIC power switch 115, and other equipment to achieve intelligent power distribution, temperature control, and fault early warning for the entire system.

[0022] Example 2 The implementation examples are basically as follows Figure 1 and Figure 11 As shown: A segmented electrically heated assisted heavy oil extraction method includes the following steps: S1: Inject 80-120℃ saturated water into the reservoir through vertical wells, controlling the saturated water volume at 20-27t and controlling the injection pressure at 70%-90% of the formation fracture pressure; S2: Synchronously start the auxiliary pipe built-in heating section cable 11, and use segmented temperature control technology to heat the saturated water. Use thermocouple 27 to monitor the downhole temperature, control the temperature of the vertical section at 150-250℃, the temperature of the horizontal section at 250-350℃, and control the temperature gradient of the heating section within ±2℃. The specific segmented temperature control technology is as follows: Vertical section: The temperature for vertical depths of 10-60m is controlled at 150℃, the temperature for vertical depths of 61-110m is controlled at 200℃, and the temperature for vertical depths of 111-180m is controlled at 245℃. Horizontal section: Control the temperature at 260℃ for 10-130m from the vertical section, at 300℃ for 131-240m from the vertical section, and at 345℃ for 240-380m from the vertical section; S3: Saturated water is heated to form steam, which enters the oil layer for preheating, maintaining the wellbore temperature at 100-150℃; S4: Inject saturated steam into the horizontal well at a temperature of 300℃ and an injection rate of 15 m³ / h. Inject nitrogen into the vertical well to assist in expansion, with the nitrogen injection volume accounting for 10% of the steam volume. Control the dryness of the injected steam at 75%. S5: The staff closes the wellhead and begins the well shut-in operation, controlling the well shut-in time to 45 days. During this period, thermocouple 27 is used to monitor the downhole temperature and maintain the reservoir temperature at 150℃. S6: After the well is shut down, horizontal well production is started, and the bottom hole flowing pressure is monitored in real time. The saturated steam pressure is controlled to 70% of the formation fracture pressure. After the reservoir steam replaces the fluid, it is squeezed into screen pipe 13 and then enters the production casing 8 from screen pipe 13. It is then extracted by the pumping pump of the main pipe 9. During the production process, the fluid replacement method without stopping the well is adopted by adjusting the oil nozzle. The specific details are as follows: When the injection-to-sampling ratio is <0.9 or the pump inlet pressure is > saturated steam pressure, gradually reduce the nozzle size by 0.5 mm each time. When the temperature at the end of the horizontal section suddenly rises by 20°C, the nozzle is gradually enlarged by 0.8 mm each time.

[0023] The above descriptions are merely embodiments of the present invention, and common knowledge regarding specific structures and characteristics is not elaborated upon here. It should be noted that those skilled in the art can make various modifications and improvements without departing from the structure of the present invention, and these should also be considered within the scope of protection of the present invention. These modifications and improvements will not affect the effectiveness of the present invention or the practicality of the patent. The scope of protection claimed in this application should be determined by the content of its claims, and the specific embodiments described in the specification can be used to interpret the content of the claims.

Claims

1. A segmented electrically heated assisted heavy oil extraction system, characterized in that, The system includes an above-ground power supply station (1), transformer control cabinet (2), junction box (3), injection / production skid (4), power supply section cable (5), cable connector (6), and wellhead (7); and an underground production casing (8), main pipe (9), auxiliary pipe (10), heating section cable (11), hanger (28), and screen pipe (13). The power supply station (1) is electrically connected to the transformer control cabinet (2), the transformer control cabinet (2) is electrically connected to the junction box (3), the transformer control cabinet (2) is electrically connected to the injection / production skid (4), the power supply section cable (5) is connected to the transformer control cabinet (2), the production casing (8) is connected to the wellhead (7), the hanger (28) is located inside the production casing (8), and the screen pipe (13) is connected to the production casing (8) through the hanger (28). The main pipe (9) is located inside the production sleeve (8), the secondary pipe (10) is located inside the production sleeve (8) and the screen pipe (13), the heating section cable (11) is located inside the secondary pipe (10), the heating section cable (11) consists of a central support line (111), several heating modules (112), several module spacers (113) and a metal sheath (114) from the inside out, several heating modules (112) are evenly connected in series on the central support line (111), several module spacers (113) are located between two adjacent heating modules (112), each heating module (112) integrates a SIC power switch (115), the heating section cable (11) and the power supply section cable (5) are connected through a cable connector (6).

2. The segmented electrically heated assisted heavy oil extraction system according to claim 1, characterized in that, The transformer control cabinet (2) is connected to an air supply unit (12). The air supply unit (12) includes a ground air collection assembly and an underground transmission pipeline. The ground air collection assembly consists of a fan (121), an air collection pipe (122), an air supply pipe (123), and a pipe sleeve (124). The underground transmission pipeline is connected by an L-shaped pipe (125) and a straight pipe (126). The air collection pipe (122) is sealed to the air outlet of the fan (121). The air collection pipe (122) and the air outlet of the fan (121) are connected to the air supply unit (124). A straight pipe (126) is connected, and the horizontal section of the straight pipe (126) is detachably connected to the horizontal section of the L-shaped pipe (125). Several diverter plates (127) are provided inside the straight pipe (126). The vertical section of the L-shaped pipe (125) is connected to the air supply pipe (123) at one end on the ground. The air supply pipe (123) is sealed to the pipe sleeve (124). The bottom of the transformer power control cabinet (2) is provided with an air conditioning chamber (29). The pipe sleeve (124) is connected to the air conditioning chamber (29).

3. A segmented electrically heated assisted heavy oil extraction system according to claim 2, characterized in that, The transformer power control cabinet (2) is provided with a dust cover (14), and the dust cover (14) is provided with several ventilation holes (15). Each ventilation hole (15) is provided with a filter screen (16), and a door panel (17) is provided on one side of the dust cover (14).

4. A heavy oil extraction system according to claim 2, characterized in that, The fan (121) has a one-way bearing (18) on its shaft. A pressure collection box (19) is fixedly connected through the fan (121) shaft. A bevel gear (20) is fixedly connected to the outer ring of the one-way bearing (18). A bevel gear (21) is provided inside the pressure collection box (19). The bevel gear (20) meshes with the bevel gear (21). A connecting rod (22) is fixedly connected to the bevel gear (21). Several blades (23) are provided on the connecting rod (22). The connecting rod (22) and several blades (23) are located inside the pressure collection box (19). A pressure discharge pipe (24) is connected to one side of the pressure collection box (19). The free end of the pressure discharge pipe (24) is located at the cable connector (6).

5. A segmented electrically heated assisted heavy oil extraction system according to claim 4, characterized in that, The cable connector (6) has a fixing frame (25) on one side, and an infrared thermal imager (26) is mounted on the fixing frame (25).

6. A segmented electrically heated assisted heavy oil extraction system according to claim 5, characterized in that, Several thermocouples (27) are provided on the main pipe (9), screen pipe (13) and heating section cable (11). The transformer power control cabinet (2), power supply section cable (5), cable connector (6), SIC power switch (115), injection and extraction skid (4), fan (121) and infrared thermal imager (26) are all connected to the PLC controller.

7. A segmented electrically heated assisted heavy oil extraction method, characterized in that, Includes the following steps: S1: Inject 80-120℃ saturated water into the reservoir through vertical wells, controlling the saturated water volume at 20-27t and controlling the injection pressure at 70%-90% of the formation fracture pressure; S2: Synchronously start the cable (11) of the built-in heating section of the auxiliary pipe, use segmented temperature control technology to heat the saturated water, use thermocouple (27) to monitor the downhole temperature, control the temperature of the vertical section at 150-250℃, control the temperature of the horizontal section at 250-350℃, and control the temperature gradient of the heating section within ±2℃. S3: Saturated water is heated to form steam, which enters the oil layer for preheating, maintaining the wellbore temperature at 100-150℃; S4: Inject saturated steam into the horizontal well, with the temperature controlled at 240-320℃ and the injection rate at 8-15 m³ / h. Inject nitrogen into the vertical well to assist in volume expansion, with the nitrogen injection volume accounting for 5-15% of the steam volume. S5: The staff closes the wellhead and begins the well shut-in operation, controlling the well shut-in time to 20-60 days. During this period, thermocouples are used to monitor the downhole temperature and maintain the reservoir temperature at 150-200℃. S6: After the well is shut down, start production in the horizontal well, monitor the bottom pressure in real time, and control the saturated steam pressure to 70-90% of the formation fracture pressure. After the reservoir steam replaces the liquid, it is squeezed into the screen pipe (13) and enters the production casing (8) from the screen pipe (13) and is extracted by the pumping pump of the main pipe (9).

8. A segmented electrically heated assisted heavy oil extraction method according to claim 7, characterized in that, The segmented temperature control technology in step S2 is as follows: Vertical section: The temperature for vertical depths of 10-60m is controlled at 150±5℃, the temperature for vertical depths of 61-110m is controlled at 200±5℃, and the temperature for vertical depths of 111-180m is controlled at 245±5℃. Horizontal section: The temperature at a distance of 10-130m from the vertical section is controlled at 260±5℃, the temperature at a distance of 131-240m from the vertical section is controlled at 300±5℃, and the temperature at a distance of 240-380m from the vertical section is controlled at 345±5℃.

9. A segmented electrically heated assisted heavy oil extraction method according to claim 8, characterized in that, The dryness of the injected steam should be controlled at 75-85%.

10. A segmented electrically heated assisted heavy oil extraction method according to claim 9, characterized in that, During the extraction process, a non-stop fluid replacement method using adjustable nozzles is adopted, the specific details of which are as follows: When the injection-to-sumption ratio is <0.9 or the pump inlet pressure is > saturated steam pressure, gradually reduce the nozzle size by 0.3-0.7 mm each time. When the temperature at the end of the horizontal section suddenly rises by 20°C, gradually enlarge the nozzle by 0.5-1mm each time.

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