Microwave-assisted steam oil extraction device for heavy oil well and use method of microwave-assisted steam oil extraction device

Abstract

The invention discloses a thick oil well microwave-assisted steam oil extraction device and a using method thereof, the thick oil well microwave-assisted steam oil extraction device comprises an oil extraction lifting system connected with a steam injection system, and the thick oil well microwave-assisted steam oil extraction device is characterized by further comprising a microwave heating system connected with a shaft pipe column of the oil extraction lifting system. The microwave heating system comprises a microwave generating device, a microwave waveguide tube bundle and a microwave heating short section which are connected in sequence; the microwave generating and transmitting device can generate microwaves, and the microwaves are transmitted to the microwave heating short section through the microwave waveguide tube bundle. The temperature and dryness of high-temperature steam can be maintained when the high-temperature steam is conveyed along a shaft, the fluidity of thickened oil during extraction can be improved, and the requirement for heat preservation and dryness protection in the whole steam huff and puff extraction process of the thickened oil can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of heavy oil extraction, and specifically to a microwave-assisted steam oil production device for heavy oil wells and its usage method. Background Art

[0002] In China, heavy oil resources are rich in reserves, widely distributed, and have great development potential. Due to the high viscosity and poor fluidity of heavy oil, it is difficult to flow in the formation and to be lifted in the wellbore. Currently, mainly based on the characteristic that the viscosity of heavy oil decreases as the temperature rises, thermal oil recovery, that is, injecting high-temperature steam into the formation, is used to develop heavy oil reservoirs. Common methods include steam huff and puff, steam flooding, gravity-assisted steam drainage (SAGD), etc. Currently, the most widely used development method in China is steam huff and puff.

[0003] Steam huff and puff development is a method in which high-temperature steam is first injected into the oil well. After the steam injection is completed, the well is shut in. After the high-temperature steam heats the heavy oil in the oil layer, the well is reopened to produce the heavy oil. Steam huff and puff development usually faces two problems. One is that during the transportation of high-temperature steam in the oil wellbore, heat loss of the high-temperature steam will inevitably occur, resulting in a decrease in steam temperature and steam dryness, and further affecting the heating effect of the steam on the formation, leading to poor oil well production. The other is that although the heavy oil has fluidity after being heated by high-temperature steam in the formation, after it flows into the oil wellbore, the temperature of the heavy oil will gradually decrease and its fluidity will become poor, or even lose its fluidity, resulting in difficulties in lifting the heavy oil in the oil wellbore or the oil wellbore being blocked by heavy oil.

[0004] In response to these two problems, there is an urgent need in the industrial field for an efficient, economical, and convenient method for injecting steam and insulating oil production in heavy oil wells to ensure that the steam dryness and temperature in the wellbore do not decrease during steam injection, and that the heavy oil maintains good fluidity in the wellbore during heavy oil production.

[0005] Publication (Announcement) No.: CN115704556A discloses a heavy oil thermal recovery steam production system based on the complementarity of heat pumps and concentrated solar energy, including a solar heat collection subsystem, a heat pump subsystem, a steam production subsystem, and a supplementary combustion and energy storage subsystem; using clean and renewable solar energy resources in the field of heavy oil thermal recovery to open up a new way for the clean and efficient exploitation of heavy oil, replacing part of the fossil energy with solar energy to reduce pollutant emissions. Through the heat pump unit, a large amount of waste heat from oilfield sewage can be fully utilized to preheat the steam required for oil production, which can effectively improve the overall energy utilization efficiency of the system. With the help of the heat pump unit, low-temperature solar waste heat, high-temperature solar energy, and boiler heating modes, the "grade matching and cascade utilization" of energy can be realized, reducing the irreversible loss during the energy utilization process and improving the economic efficiency of system operation. The solar steam production scheme adopts a double-loop system, which can more flexibly adjust the steam parameters according to the steam injection requirements.

[0006] This prior art reduces the energy consumed in steam flooding by using green energy, but it cannot solve the problems of temperature and dryness decline during the downhole process of the injected gas and the temperature drop and viscosity increase during the uphole process of the heavy oil.

[0007] Publication (Announcement) Number: CN217001807U discloses an injection-production string for steam huff and puff wells. The injection-production string for steam huff and puff wells of the present utility model includes: a combined tubing string, which includes an upper tubing section and a lower tubing section, and the upper tubing section is a heat-insulating tubing; a packer, which is located between the upper tubing section and the lower tubing section; an eccentric heavy oil pump, which is connected in series on the lower tubing section; a compensator, which is connected in series on the lower tubing section; and a steam distribution unit, which is connected to the lower end of the lower tubing section for injecting steam into the production casing. The injection-production string for steam huff and puff wells of this prior art generally ensures the heating effect of steam on the heavy oil, reduces the oil production resistance, ensures the length change during the thermal expansion and contraction of the tubing string, and protects the tubing string from being easily damaged.

[0008] This prior art delays the temperature and dryness decline during the downhole process of the gas by increasing the heat preservation means on the tubing. When the wellbore of the oil well is relatively long, the steam temperature and dryness will still decline, and the oil production efficiency still cannot reach the highest level.

[0009] Publication (Announcement) Number: CN111255424B discloses a thermal recovery string and an oil production method thereof. The thermal recovery string includes: a tubing string arranged in the wellbore; a packer, which is spacedly arranged in the horizontal section of the wellbore and is located on both sides of the casing perforation or screen slot on the wellbore; a thermal oil production valve, which is arranged on the tubing string for oil production and corresponds to the area of the casing perforation or screen slot on the wellbore; and a thermal injection valve, which is used for injecting steam. The thermal injection valve is arranged behind the thermal oil production valve and is alternately arranged with the thermal oil production valve in the horizontal section of the tubing string and corresponds to the area of the casing perforation or screen slot. This thermal recovery string can improve the development degree of heavy oil reservoirs.

[0010] This prior art controls the steam huff and puff direction through multiple thermal oil production valves to achieve uniform steam injection, but the steam temperature and dryness will still decline, and the oil production efficiency still cannot reach the highest level.

[0011] In summary, the technical solutions, the technical problems to be solved, and the beneficial effects of the above-disclosed technologies are all different from those of the present invention. There is no technical inspiration in the above-disclosed technical documents for more technical features, the technical problems to be solved, and the beneficial effects of the present invention. Summary of the Invention

[0012] In view of the above-mentioned defects existing in the prior art, the object of the present invention is to ensure zero reduction in the temperature and dryness of high-temperature steam in the wellbore during steam injection, maximize the bottom-hole steam dryness; during the production of heavy oil, it can also keep the temperature of the heavy oil in the oil well wellbore from decreasing, ensure the fluidity of the heavy oil in the wellbore, reduce the power consumption of the oil production lifting system, and prevent the heavy oil from blocking the oil well wellbore.

[0013] To achieve the above object, the present invention adopts the following technical solutions:

[0014] A microwave-assisted steam oil production device for heavy oil wells includes an oil production lifting system, the oil production lifting system is connected to a steam injection system, and further includes a microwave heating system, the microwave heating system is connected to the wellbore string of the oil production lifting system.

[0015] The oil production lifting system includes a wellbore string and a pumping unit;

[0016] The pumping unit is connected to a tubing head, the lower end of the tubing head is connected with a wellbore tubing and a casing head, and the lower end of the casing head is connected with a wellbore casing to sleeve the wellbore tubing therein.

[0017] The steam injection system includes a high-temperature steam boiler and a steam transmission pipeline, and the high-temperature steam boiler is connected to the tubing head through the steam transmission pipeline.

[0018] The microwave heating system includes a microwave generating device, a microwave waveguide bundle, and a microwave heating stub connected in sequence;

[0019] The microwave generating and transmitting device can generate microwaves and transmit the microwaves to the microwave heating stub through the microwave waveguide bundle.

[0020] The microwave generating device includes a controller, a magnetron, and a power divider connected in sequence;

[0021] The controller is used to control the power switch and the power divider; the magnetron is used to convert the supplied electrical energy into microwave energy.

[0022] A temperature monitoring device is provided on the microwave heating stub, and at least two microwave heating stubs are provided on the wellbore tubing;

[0023] The number of microwave waveguides in the microwave waveguide bundle is the same as the number of microwave heating stubs, at least two;

[0024] The microwave heating stubs are connected to the microwave waveguides one by one to form a plurality of, at least two mutually independent microwave heating paths.

[0025] The microwave waveguides are aggregated into a microwave waveguide bundle;

[0026] The microwave waveguide bundle penetrates through the casing head and is connected to the output end of the wave divider;

[0027] The wave divider can control the opening and closing of each independent microwave heating path.

[0028] The microwave waveguide is made of a hollow metal hose, its surface is wrapped with an insulating coating, and its interior is filled with a wave - guiding material.

[0029] The upper and lower ends of the microwave heating short section are connected to the wellbore tubing string, and the material of the microwave heating short section is the same as that of the wellbore tubing string.

[0030] To achieve the above - mentioned purpose, the present invention adopts the following technical solutions:

[0031] A method for using a microwave - assisted steam oil production device for viscous oil wells includes the following steps:

[0032] S1: Gas injection preparation; Shut down the oil production lifting system, set the steam temperature warning value, start the high - temperature steam boiler to produce high - quality steam, and the high - quality steam flows through the steam transmission pipeline to the wellhead of the oil well;

[0033] S2: Steam wellbore heat and dryness preservation; The steam flows from the wellhead through the tubing to the bottom of the well. When the steam flows through the microwave heating short section, the steam temperature is detected by the temperature monitoring device in the microwave heating short section. When the steam temperature is lower than or equal to the warning value, the microwave heating system starts to work. The controller in the microwave heating device controls the power supply to convert electrical energy into microwave energy by the magnetron. The wave divider controls the microwave transmission path and transmits the microwave into the microwave heating short section in a warning state. After the microwave enters the microwave heating short section, a microwave heating field is formed in the short - section cavity to heat the steam flowing through it. After microwave heating, the steam temperature is raised above the warning value;

[0034] When the steam temperature is higher than the warning value, the microwave heating system does not generate microwaves;

[0035] The high - temperature gas reaches the bottom of the well after passing through multiple microwave heating short sections;

[0036] S3: Viscous oil extraction preparation; Shut down the steam injection system, set the lowest oil temperature warning value, and after the steam fully heats the viscous oil in the formation, open the oil production lifting system;

[0037] S4: Thermal insulation for heavy oil extraction; When extracting oil from the bottom of the well, the heavy oil flows towards the wellhead through the tubing. The temperature of the heavy oil is detected by the temperature monitoring device in the microwave heating section. When the temperature of the heavy oil is lower than or equal to the warning value, the microwave heating system starts to work. The controller in the microwave heating device controls the power supply to convert the electrical energy of the magnetron into microwave energy. The wave divider controls the microwave transmission path and transmits the microwave into the microwave heating section in a warning state. After the microwave enters the microwave heating section, a microwave heating field is formed in the short - section cavity to heat the heavy oil flowing through it. After microwave heating, the temperature of the heavy oil rises above the warning value;

[0038] When the temperature of the heavy oil is higher than the warning value, the microwave heating system does not generate microwaves;

[0039] The heavy oil is extracted from the wellhead after passing through multiple microwave heating sections.

[0040] The present invention has the following beneficial effects compared with the prior art:

[0041] 1) It can ensure that the dryness and temperature of the steam do not decrease during the steam injection stage when the steam is transported in the wellbore, improve the temperature and dryness of the steam when it reaches the bottom of the well, increase the heat carried by the steam for heating the formation, expand the heating range of the steam in the reservoir, enable steam stimulation to extract a wider range of heavy oil with higher efficiency, and improve the single - well production capacity of heavy - oil wells and the ultimate recovery rate of heavy - oil reservoirs.

[0042] 2) The steam has a wide thermal insulation range and can still increase the temperature and dryness of high - temperature steam above 200 degrees Celsius, overcoming the defect that the traditional wellbore heating and insulation method is only applicable to low - temperature ranges.

[0043] 3) It can ensure that the temperature of the heavy oil does not decrease during the lifting process of the heavy oil in the wellbore during the oil production stage, ensure that the heavy oil maintains good fluidity during the lifting process, reduce the energy consumption of the oil well lifting system, reduce the risk of the heavy oil blocking the wellbore due to the loss of fluidity, and save the chemical agent costs and labor costs generated by methods such as mixing with light oil or injecting viscosity - reducing agents.

[0044] 4) It does not change the structure of the wellbore tubing string of the oil well, does not occupy the space inside the tubing, does not affect the normal operation of the oil production system, and the microwave heating device can be adapted to most of the wellbore tubing string structures that have been put into use, with wide applicability.

[0045] 5) It can simultaneously meet the thermal insulation requirements of the steam in the steam injection stage and the heavy oil in the oil production stage, without the need to replace the wellbore tubing string when switching between the steam injection stage and the oil production stage, realizing the integrated use of the tubing string for injection and production in steam stimulation, reducing the adjustment workload in the injection and production stages of the oil well, and having high convenience;

[0046] 6) It can flexibly set the microwave heating position according to the actual on-site situation, and real-time regulate the working state of the set microwave heating short section to meet the personalized needs of steam injection and heavy oil lifting, with strong flexibility. Brief Description of the Drawings

[0047] Figure 1 It is a schematic structural diagram of a microwave-assisted steam oil production device and method for heavy oil wells provided by the present invention.

[0048] In the figure, 1. Controller; 2. Magnetron; 3. Wave divider; 4. Microwave waveguide bundle; 5. Microwave heating short section; 6. Temperature monitoring device; 7. High-temperature steam boiler; 8. Ground steam transmission pipeline; 9. Tubing head; 10. Casing head; 11. Wellbore casing; 12. Wellbore tubing; 13. Pumping unit Detailed Embodiments

[0049] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0050] Please refer to Figure 1 , a microwave-assisted steam oil production device for heavy oil wells provided by the present invention and its usage method, including an oil production lifting system, a steam injection system connected to the oil production lifting system, and further including a microwave heating system connected to the wellbore string of the oil production lifting system;

[0051] The oil production lifting system includes a wellbore string and a pumping unit 13. The pumping unit 13 is connected to the tubing joint 9. The lower end of the tubing head 9 is connected with a wellbore tubing 12 and a casing head 10. The lower end of the casing head 10 is connected with a wellbore casing 11 to sleeve the wellbore tubing 12 therein;

[0052] The steam injection system includes a high-temperature steam boiler 7 and a steam transmission pipeline 8. The high-temperature steam boiler 7 is connected to the tubing joint 9 through the steam transmission pipeline 8;

[0053] The microwave heating system includes a microwave generating device, a microwave waveguide bundle 4, and a microwave heating short section 5 connected in sequence;

[0054] The microwave generating and transmitting device can generate microwaves and transmit the microwaves to the microwave heating short section 5 through the microwave waveguide bundle 4;

[0055] The microwave generating device includes a controller 1, a magnetron 2, and a wave divider 3 connected in sequence; the controller 1 is used to control the power switch and the wave divider 3; the magnetron 2 is used to convert the supplied electrical energy into microwave energy;

[0056] A temperature monitoring device is provided on the microwave heating nipple 5, and multiple, at least two, microwave heating nipples are provided on the wellbore tubing; the temperature monitoring device 6 can measure the temperature of the fluid flowing through the microwave heating nipple 5;

[0057] The number of the microwave heating nipples 5 is the same as the number of the microwave waveguides in the microwave waveguide bundle 4, which is multiple, at least two. The microwave heating nipples 5 are connected to the microwave waveguides one by one to form multiple, at least two independent microwave heating paths. The specific position and specific number of the microwave heating nipples 5 are determined according to the length of the oil wellbore, the power of the microwave generator, and the actual physical properties of the steam and heavy oil.

[0058] The microwave waveguides are aggregated into a microwave waveguide bundle 4. The microwave waveguide bundle 4 passes through the casing head 9 and is connected to the output end of the wave divider 3. The wave divider 3 can control the opening and closing of each independent microwave heating path.

[0059] The wave divider 3 is located between the magnetron 2 and the microwave waveguide bundle 4 and can be used to selectively transport the microwaves generated by the magnetron 2 into the microwave waveguides in the microwave waveguide bundle 4. This selective control process is controlled by the controller 1. At the same time, the wave divider 3 can block the microwaves reflected from the microwave waveguide bundle 4 to protect the magnetron.

[0060] The microwave waveguides in the microwave waveguide bundle 4 are made of hollow metal hoses, the surface is wrapped with an insulating coating, and the inside of the tube is filled with a wave guiding material.

[0061] The insulating coating on the surface of the microwave waveguides in the microwave waveguide bundle 4 can reduce the loss of microwave energy. The inside of the tube is filled with polytetrafluoroethylene material with good wave guiding properties. The polytetrafluoroethylene as the filling material can improve the transmission performance of microwaves in the microwave waveguides.

[0062] The microwave heating nipple 5 is a tubing nipple with a microwave waveguide connected to the outer wall. Its upper end and lower end are connected to the wellbore tubing string, and the material is the same as that of the tubing string.

[0063] When microwaves enter the microwave heating nipple 5, they will be reflected in the cylindrical space inside the microwave heating nipple 5, and the heating flow will increase the temperature or dryness of the high-temperature steam or heavy oil passing through the microwave heating nipple 5.

[0064] The controller 1 can receive and process the temperature data of the temperature monitoring device 6. Whether the microwave heating sub-section 5 functions as a heater is controlled in real time by the controller 1. When it is not necessary for the microwave heating sub-section 5 at a certain position to operate, the controller 1 can control the diplexer 3 to close the connection between the magnetron 2 and the microwave waveguide, cutting off the microwave transmission.

[0065] Embodiment 1:

[0066] During high-temperature steam injection, the steam in the wellbore is thermally insulated and kept dry.

[0067] When the oil well enters the steam injection stage of steam huff and puff, the oil production lifting system is temporarily shut down, and the high-temperature steam boiler 7 starts to operate, generating high-temperature steam. The high-temperature steam passes through the ground steam transmission pipeline 8 and enters the tubing head 9 of the wellhead Christmas tree of the oil well, and then enters the wellbore tubing 12. After the high-temperature steam is transported in the wellbore tubing 12 for a certain distance, since the temperature of the high-temperature steam is 200 - 350 °C, which is much higher than the temperature of the wellbore and the formation outside the wellbore, the heat of the high-temperature steam will dissipate outward through the wellbore tubing 12 and the wellbore casing 11, and the temperature of the high-temperature steam will gradually decrease. After the temperature of the high-temperature steam drops to a certain extent, part of the steam will be re-liquefied, resulting in a decrease in the dryness of the high-temperature steam. When the high-temperature steam flows in the wellbore tubing 12 and passes through the temperature monitoring device 6 in the microwave heating sub-section 5, the temperature of the high-temperature steam is measured.

[0068] When the temperature of the high-temperature steam is lower than or equal to the set warning value, the temperature monitoring device 6 puts the corresponding microwave heating sub-section 5 into a warning state;

[0069] The controller 1 starts to operate. The controller 1 turns on the power switch to enable the magnetron 2 to convert electrical energy into microwave energy. The controller 1 controls the selective connection of the diplexer 3 to transmit the microwave into the microwave waveguide in the warning state, and finally the microwave enters the microwave heating sub-section 5 in the warning state;

[0070] The high-temperature steam in the microwave heating sub-section 5 in the warning state generates polar molecular oscillations under the action of the microwave, increasing the temperature. The originally partially liquefied water will also be re-converted into steam, returning to a high-temperature and high-dryness state.

[0071] When the gas temperature is higher than the warning value, the microwave heating system does not generate microwaves;

[0072] The high-temperature steam undergoes the above process several times in the wellbore and finally reaches the bottom of the well, entering the formation in a high-temperature and high-dryness state, fully heating the heavy oil in the formation, and achieving the purpose of significantly improving the heavy oil recovery rate.

[0073] Embodiment 2:

[0074] During heavy oil production, the heavy oil in the wellbore is thermally insulated.

[0075] After the steam injection is completed, the high-temperature steam boiler 7 suspends operation. After the steam fully heats the heavy oil in the formation, the oil production lifting system starts to work. The heavy oil in the formation is heated by the steam, its temperature rises, its viscosity decreases, and its fluidity increases. It then enters the casing 11 of the oil well borehole and the tubing 12 of the wellbore through formation seepage.

[0076] After the oil production lifting system starts to work, the heavy oil in the tubing 12 of the wellbore flows upward in the tubing 12 of the wellbore under the action of pumping. Since the temperature of the heated heavy oil is higher than the original formation temperature, the heavy oil will also lose heat in the wellbore and its temperature will decrease. When the temperature of the heavy oil decreases to a certain extent, the viscosity of the heavy oil increases and its fluidity becomes poor.

[0077] At this time, the heavy oil will flow through the microwave heating section 5, and the temperature of the heavy oil is monitored by the temperature monitoring device 6 in the microwave heating section 5.

[0078] When the temperature is lower than or equal to the warning value, the controller 1 turns on the power switch to convert the electrical energy of the magnetron 2 into microwave energy. The controller 1 controls the selective connection of the power divider 3 to transmit the microwave to the microwave waveguide in the warning state, and finally the microwave enters the microwave heating section 5 in the warning state. Under the action of the microwave in the microwave heating section 5, the heavy oil generates polar molecular oscillations and its temperature rises rapidly. The viscosity of the heavy oil decreases again and its fluidity increases, so it can continue to flow upward.

[0079] When the temperature of the heavy oil is higher than the warning value, the microwave heating system does not generate microwaves.

[0080] The heavy oil undergoes the above process several times before flowing to the wellhead, and finally is successfully lifted from the bottom of the well to the wellhead.

[0081] It should be noted that the controller 1 used in the present invention adopts a conventional PLC or single-chip microcomputer, which can be directly purchased, wired and used. The magnetron 2 is a microwave generating element, which is an existing technology and is well known to those skilled in the art.

[0082] Combining all embodiments, the usage method of this device:

[0083] S1: Injection gas preparation;

[0084] Shut down the oil production lifting system, set the warning value of the steam temperature, start the steam injection system to produce high-quality steam, and the high-quality steam flows to the wellhead of the oil well through the steam transmission pipeline 8.

[0085] S2: Steam wellbore heat preservation and moisture preservation

[0086] The steam flows from the wellhead to the bottom of the well through the tubing, and the temperature of the steam in the tubing is detected by the temperature monitoring device 6 in the microwave heating section 5.

[0087] When the steam temperature is lower than or equal to the warning value, the microwave heating system starts to work. The controller 1 in the microwave heating device controls the power supply to enable the magnetron 2 to convert electrical energy into microwave energy. The wave divider 3 controls the microwave transmission path and transmits the microwave into the microwave heating stub 5 in a warning state. After the microwave enters the microwave heating stub 5, a microwave heating field is formed in the stub cavity to heat the steam flowing through it.

[0088] When the gas temperature is higher than the warning value, the microwave heating system does not generate microwaves.

[0089] The high-temperature gas reaches the bottom of the well after passing through multiple microwave heating stubs 5; it enters the formation in a high-temperature and high-quality state to fully heat the heavy oil in the formation.

[0090] S3: Preparation for heavy oil extraction;

[0091] Close the steam injection system. After the steam fully heats the heavy oil in the formation, start the oil production lifting system.

[0092] S4: Heat preservation for heavy oil extraction;

[0093] After the oil production lifting system starts to work, the heavy oil in the wellbore tubing 12 flows upward in the wellbore tubing 12 under the action of pumping. When it flows through the microwave heating stub 5, the temperature of the heavy oil is monitored by the temperature monitoring device 6 in the microwave heating stub 5.

[0094] When the temperature is lower than or equal to the warning value, the microwave heating system starts to work. The controller 1 in the microwave heating device controls the power supply to enable the magnetron 2 to convert electrical energy into microwave energy. The wave divider 3 controls the microwave transmission path and transmits the microwave into the microwave heating stub 5 in a warning state. After the microwave enters the microwave heating stub 5, a microwave heating field is formed in the stub cavity to heat the heavy oil; the viscosity of the heavy oil decreases again and its fluidity increases, so it can continue to flow upward.

[0095] When the temperature of the heavy oil is higher than the warning value, the microwave heating system does not generate microwaves.

[0096] The high-temperature heavy oil is produced from the wellhead after passing through multiple microwave heating stubs 5.

[0097] For the components themselves that are not elaborated in this application and the connection methods of the components in this application, they all belong to the well-known technologies in the technical field. They can be directly applied without further elaboration.

[0098] In the present invention, the term "a plurality of" means two or more, unless otherwise clearly defined. Terms such as "installed", "connected", "coupled", "fixed", etc. should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral connection; "coupled" can be a direct connection or an indirect connection through an intermediate medium. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0099] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or unit referred to must have a specific direction, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of the present invention.

[0100] In the description of this specification, the descriptions of terms such as "one embodiment", "some embodiments", "specific embodiments", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or instance. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0101] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A microwave-assisted steam oil production device for heavy oil wells, comprising an oil production lifting system, wherein the oil production lifting system is connected to a steam injection system, It is characterized in that further comprising a microwave heating system, and the microwave heating system is connected to the wellbore string of the oil production lifting system.

2. The microwave-assisted steam oil production device for heavy oil wells according to claim 1, wherein The oil production lifting system includes a wellbore string and a pumping unit; The pumping unit is connected to a tubing joint, and a wellbore tubing and a casing head are connected to the lower end of the tubing head, and a wellbore casing is connected to the lower end of the casing head to sleeve the wellbore tubing therein.

3. A microwave-assisted steam injection production device for heavy oil wells according to claim 2, characterized in that, The steam injection system includes a high-temperature steam boiler and a steam transmission pipeline, and the high-temperature steam boiler is connected to the tubing joint through the steam transmission pipeline.

4. A microwave-assisted steam injection production device for heavy oil wells according to claim 3, characterized in that The microwave heating system includes a microwave generating device, a microwave waveguide bundle, and a microwave heating stub connected in sequence; The microwave generating and transmitting device can generate microwaves and transmit the microwaves to the microwave heating stub through the microwave waveguide bundle.

5. A microwave-assisted steam oil recovery device for heavy oil wells according to claim 4, characterized in that, The microwave generating device includes a controller, a magnetron, and a wave divider connected in sequence; The controller is used to control the power switch and the wave divider; the magnetron is used to convert the supplied electrical energy into microwave energy.

6. A microwave-assisted steam injection production device for heavy oil wells according to claim 5, characterized in that, A temperature monitoring device is provided on the microwave heating stub, and at least two microwave heating stubs are provided on the wellbore tubing; The number of microwave waveguides in the microwave waveguide bundle is the same as the number of microwave heating stubs; The microwave heating stubs are connected to the microwave waveguides one by one to form a plurality of, at least two independent microwave heating paths.

7. A microwave-assisted steam oil recovery device for heavy oil wells according to claim 6, characterized in that, The microwave waveguides are aggregated into a microwave waveguide bundle; The microwave waveguide bundle passes through the casing head and is connected to the output end of the wave divider; The wave divider can control the opening and closing of each independent microwave heating path.

8. A microwave-assisted steam oil recovery device for heavy oil wells according to claim 7, characterized in that The microwave waveguide is made of a hollow metal hose, the surface is wrapped with an insulating coating, and the inside of the tube is filled with a wave guiding material.

9. The microwave-assisted steam oil production device for heavy oil wells according to claim 9, characterized in that, The upper and lower ends of the microwave heating stub are connected to the wellbore tubing string, and the material of the microwave heating stub is the same as that of the wellbore tubing string.

10. A method for using a microwave-assisted steam oil production device for heavy oil wells, comprising the following steps: S1: The step of gas injection preparation; S2: The step of gas injection and heat preservation; S3: The step of heavy oil extraction preparation; S4: The step of heavy oil extraction and heat preservation.

11. A method for using a microwave-assisted steam injection production device for heavy oil wells according to claim 11, characterized in that, The specific steps are as follows: S1: Gas injection preparation; Shut down the oil production lifting system, set the steam temperature warning value, start the high-temperature steam boiler to produce high-quality steam, and the high-quality steam flows to the wellhead of the oil well through the steam transmission pipeline; S2: Steam wellbore heat preservation and dryness preservation; The steam flows from the wellhead through the tubing to the bottom of the well. When the steam flows through the microwave heating stub, the steam temperature is detected by the temperature monitoring device in the microwave heating stub. When the steam temperature is lower than or equal to the warning value, the microwave heating system starts to work. The controller in the microwave heating device controls the power supply to make the magnetron convert electrical energy into microwave energy, and the wave divider controls the microwave transmission path to transmit the microwaves into the microwave heating stub in a warning state. After the microwaves enter the microwave heating stub, a microwave heating field is formed in the stub cavity to heat the steam flowing through it. After microwave heating, the steam temperature is raised above the warning value; When the steam temperature is higher than the warning value, the microwave heating system does not generate microwaves; The high-temperature gas reaches the bottom of the well after passing through multiple microwave heating short sections; S3: Preparation for heavy oil extraction; Shut down the steam injection system, set the minimum oil temperature warning value, and after the steam fully heats the heavy oil in the formation, turn on the oil production lifting system; S4: Heat preservation for heavy oil extraction; Extract oil from the bottom of the well. The heavy oil flows towards the wellhead through the tubing. The temperature of the heavy oil is detected by the temperature monitoring device in the microwave heating short section. When the temperature of the heavy oil is lower than or equal to the warning value, the microwave heating system starts to work. The controller in the microwave heating device controls the power supply to convert the electrical energy of the magnetron into microwave energy. The wave divider controls the microwave transmission path and transmits the microwave into the microwave heating short section in a warning state. After the microwave enters the microwave heating short section, a microwave heating field is formed in the short section cavity to heat the heavy oil flowing through it. After microwave heating, the temperature of the heavy oil is raised above the warning value; When the temperature of the heavy oil is higher than the warning value, the microwave heating system does not generate microwaves; The heavy oil is produced from the wellhead after passing through multiple microwave heating short sections.

Images