Heating system for heating production fluid from a well using well associated gas to generate power

Abstract

The application discloses a heating system for heating oil well production liquid by utilizing oil well associated gas to generate electricity, and the system comprises a natural gas generator set, a heating body provided with a heating shell and a heat conducting oil pipe filled with heat conducting oil, and a comprehensive control device which is divided into a control part and an alternating current part; three-phase alternating current power from a power grid is electrically connected with an in-out oil temperature controller, a heat conducting oil temperature controller and a heat conducting oil liquid level instrument in the control part; the alternating current part is provided with a generator switch and a single-phase control switch, the single-phase control switch is provided with three single-phase control switches which are electrically connected with three phase lines from a double-throw switch respectively, and the single-phase control switch is electrically connected with a PLC in the control part through a signal cable; the associated gas generated in the oil well production process is used to generate electricity by the natural gas generator set, and the alternating current power generated by the generator is used to heat the heat conducting oil in the heat conducting oil pipe through the generator switch and the double-throw switch; in the case that the associated gas is insufficient, the three-phase alternating current power from the power grid is used to heat the heat conducting oil through the double-throw switch.

Description

Technical Field

[0001] This invention relates to an apparatus for heating oil well produced fluids by generating electricity using associated gas from oil wells, and more particularly to a heating system for heating oil well produced fluids by generating electricity using associated gas from oil wells. Background Technology

[0002] In recent years, with increasingly stringent national environmental protection requirements, gas-fired heating furnaces used in the oil gathering process during the early stages of oilfield development have been gradually phased out due to their failure to meet environmental standards. In summary, the main technologies currently used for heating oil well production fluids are as follows:

[0003] 1. Currently, the most commonly used technology is resistance heating, which has low heating efficiency, high power consumption, and is prone to coking and damage during long-term operation. 2. Photovoltaic technology is clean and economical, but it requires sufficient sunlight and a large well site area, and the investment is large. For a heating power of 20kW, the investment cost is 300,000-400,000 yuan. Energy storage devices have limited storage capacity and rapid degradation, requiring electricity as a backup during periods of no sunlight. 3. Ground source heat pumps are only used for heating and have a short lifespan; they must be used for both heating and cooling. Air source heat pumps have a high investment cost, and their COP (coefficient of performance) is relatively low in winter, only around 2.5, resulting in only average energy savings and a large investment. 4. Low-NOx combustion technology for natural gas is suitable for large boilers. 5. Untreated associated gas fuels and small boilers cannot meet environmental protection emission standards and cannot be used.

[0004] The heating devices for oil well production fluids still need improvement.

[0005] According to the search, the associated gas generated during the production process of oil wells is mainly used for grid-connected power generation. For example, the invention patent with authorization announcement number CN102562285B discloses a practical, simple and reliable small associated gas grid-connected generator set for oil fields. It is a small gas generator set with automatic grid connection function and automatic intermittent operation function. It has a simple structure, is reliable and has a low cost. It is suitable for independent associated gas sources in oil fields with insufficient output or extremely unstable output.

[0006] However, it requires grid connection to generate electricity, which poses safety risks due to the addition of dual power supply points and involves complicated approval procedures, so it cannot be directly used for heating oil well production fluids.

[0007] Chinese patent application CN107171434A discloses a power supply system for oil fields, comprising: a gas collection device for collecting natural gas generated during oil well pumping; a gas generator set for using the collected natural gas as fuel to generate alternating current; a new energy power generation device for generating electricity using new energy sources; a diesel generator set for generating alternating current using diesel fuel; and a switching device including a first controllable switch assembly composed of at least three parallel controllable switches. The first controllable switch assembly is used to control the connection or disconnection of the power supply circuits between the load and the gas generator set, the new energy power generation device, and the diesel generator set, respectively. This patent does not directly address the heating of oil well produced fluids.

[0008] The invention patent with publication number CN112267953A discloses a Stirling power generation system for associated gas in oil fields, which generates electricity by burning associated gas in oil fields. This invention applies Stirling generator sets to the field of associated gas in oil fields; at the same time, the skid-mounted arrangement structure realizes the standardization of customized Stirling generator cogeneration modules. However, this patent still belongs to the grid-connected power generation system, and this patent is not directly used for heating oil well produced fluids. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a heating system that uses associated gas generated during oil well production to heat the oil well's produced fluids. This system utilizes mature natural gas generator technology and directly heats the oil well's produced fluids using associated gas generated during the oil well production process. This improves the utilization efficiency of associated gas and reduces production costs.

[0010] The technical solution of this invention is as follows: A heating system for heating oil well produced fluid using associated gas generated from oil wells includes a natural gas generator set, wherein: the heating element is equipped with a heating shell and a heat transfer oil pipe containing heat transfer oil, the heat transfer oil pipe being installed in the heating shell; the oil well produced fluid enters the heating shell from the oil well produced fluid inlet and flows into the crude oil export pipeline from the oil well produced fluid outlet; the integrated control device is divided into a control section and an AC section, the control section including a rectifier, PLC, inlet and outlet oil temperature controller, heat transfer oil temperature controller, and heat transfer oil level gauge, and three-phase power from the power grid. The AC power supply is electrically connected to the inlet / outlet oil temperature controller, the thermal oil temperature controller, and the thermal oil level gauge via a rectifier. The inlet / outlet oil temperature controller is electrically connected to the outlet oil temperature sensor and the inlet oil temperature sensor installed in the heating element via signal cables. The signal cables of the thermal oil temperature controller and the thermal oil level gauge are respectively electrically connected to the thermal oil temperature sensor and the thermal oil level sensor installed in the thermal oil pipe. The signal cables of the inlet / outlet oil temperature controller, the thermal oil temperature controller, and the thermal oil level gauge are electrically connected to the PLC. The AC section includes a generator switch and a double-throw switch. 、The system consists of a three-phase power switch and a single-phase control switch. Three single-phase control switches are provided, each electrically connected to one of the three phase lines from a double-throw switch. The double-throw switch is installed between the power output terminals of the three-phase power switch and the generator switch. The double-throw switch is sequentially electrically connected to the input terminals of the single-phase control switch and the thermal oil heating power supply. The single-phase control switch is electrically connected to the PLC in the control unit via a signal cable. Associated gas generated during oil well production is separated into liquids by a gas-liquid separator, then passes through a refrigerated dryer and the engine intake pipeline before entering the natural gas generator set. The natural gas engine and generator generate electricity, which is then used to heat the thermal oil in the thermal oil pipe via the generator switch and the double-throw switch. In cases of insufficient associated gas, the thermal oil is heated using the three-phase AC power from the power grid via the double-throw switch.

[0011] Preferably, a flue heat exchanger is installed at the outlet of the flue gas duct of the denitrification device in the natural gas generator set, and a heat transfer oil circulation pump is connected in series in the heat transfer oil pipeline between the inlet of the heat transfer oil pipe and the heat transfer oil outlet of the flue heat exchanger.

[0012] Preferably, the flue heat exchanger is provided with a heat exchanger heat transfer oil outlet, a heat exchanger heat transfer oil inlet, a heat transfer oil heating tube, a flue gas inlet, and a flue gas outlet; the two ends of the heat transfer oil heating tube installed in the flue heat exchanger shell are respectively connected to the heat exchanger heat transfer oil outlet and the heat exchanger heat transfer oil inlet, and the flue gas exhaust pipe outlet of the denitrification device is connected to the flue gas inlet 19-5; the heat transfer oil inlet and outlet of the heat transfer oil tube are respectively connected to the heat exchanger heat transfer oil outlet and the heat exchanger heat transfer oil inlet through heat transfer oil pipelines; the heat transfer oil heating tube is a coil and the outer wall of the coil is provided with metal fins.

[0013] Preferably, the heat-conducting oil pipe is a U-shaped pipe or a U-shaped pipe, and a graphene heating belt is also installed in the heat-conducting oil pipe. There are three graphene heating belts, namely graphene heating belt one, graphene heating belt two and graphene heating belt three. The three phase lines A, B and C of the AC power input terminal of the heat-conducting oil heating power supply are electrically connected to one end of graphene heating belt one, graphene heating belt two and graphene heating belt three respectively, and the other end of graphene heating belt one, graphene heating belt two and graphene heating belt three are electrically connected to the AC neutral line of the heat-conducting oil heating power input terminal.

[0014] Preferably, the heating shell of the heating body is welded to an oil well fluid inlet / outlet end plate and a heat transfer oil inlet / outlet end plate at both ends, and the two ends of the heat transfer oil pipe are a heat transfer oil pipe outlet and a heat transfer oil pipe inlet, respectively. The heat transfer oil pipe outlet and the heat transfer oil pipe inlet are located outside the heat transfer oil inlet / outlet end plate at one end of the heating shell; the oil well fluid inlet and the oil well fluid outlet are located outside the oil well fluid inlet / outlet end plate of the heating shell.

[0015] Preferably, an outlet and an inlet are respectively provided in the rear pipe body of the heat transfer oil pipe outlet and the heat transfer oil pipe inlet. One end of the graphene heating belt one, graphene heating belt two, and graphene heating belt three is led out from the outlet and electrically connected to the three phase lines A, B, and C of the AC power input terminal of the heat transfer oil heating power supply. The other end of the graphene heating belt one, graphene heating belt two, and graphene heating belt three is led out from the inlet and electrically connected to the neutral line of the AC power input terminal of the heat transfer oil heating power supply. High-strength sealant is filled between the outlet and the inlet and the graphene heating belt.

[0016] Preferably, the inlet oil temperature sensor and the outlet oil temperature sensor are respectively installed in the test ports of the oil well production fluid inlet and the oil well production fluid outlet; the thermal oil temperature sensor and the thermal oil level sensor are installed in the outlet of the thermal oil pipe and sealed with high-strength sealant between them; the thermal oil temperature controller and the thermal oil level meter are electrically connected to the thermal oil temperature sensor and the thermal oil level sensor respectively through signal cables.

[0017] Preferably, the outlet of the heat transfer oil pipe is located at the upper part of the heating shell, and a heat transfer oil filling port is provided in the pipe body in front of the outlet of the heat transfer oil pipe.

[0018] Preferably, a filter is connected in series between the gas supply line and the gas-liquid separator, and a gas flow meter and an electric regulating valve are also connected in series in the engine intake line between the refrigerated dryer and the natural gas generator set; the electric regulating valve is electrically connected to the PLC in the control section of the integrated control device via a signal cable.

[0019] Preferably, a 4G remote control module can also be installed in the integrated control device. The 4G remote control module is electrically connected to the PLC and can be wirelessly connected to the operator's mobile phone. The double-throw switch connected to the generator AC power supply or three-phase AC power supply is spaced 5cm-10cm away from the off side of the three-phase AC power supply or generator AC power supply.

[0020] Preferably, in the heating system for generating electricity from associated gas to heat the oil well produced fluid, the surfaces of all components in contact with the oil well produced fluid are chrome-plated, and the outer surface of the heating element is covered with insulation cotton for heat preservation; the generator is designed with a voltage of 400V, and the heating system for generating electricity from associated gas to heat the oil well produced fluid is fixed on a skid-mounted base.

[0021] Compared with existing technologies, the significant advantages of this invention are: oil well extraction generally produces associated gas. Using existing natural gas power generation technology, natural gas separated from associated gas can be directly used to generate electricity at the oil well production site, improving the utilization efficiency of associated gas. In some single wells that cannot be connected to the gathering and transmission pipeline network, associated gas produced can only be directly discharged if not used for power generation, causing air pollution and energy waste. If it is directly used to generate electricity and heat the oil well's produced fluids, it can fully utilize energy, eliminate pollution, and significantly reduce the operating costs of production units.

[0022] Graphene, after chemical treatment, can generate heat and boasts advantages such as high heating efficiency (over 95%) and long service life. Directly using graphene to heat heat transfer oil for oil well production can reduce energy consumption and effectively save production costs for operating units, demonstrating significant application value. While graphene heating technology is highly efficient, it still consumes some electricity, adding to the cost burden for production units. Utilizing associated gas from oil wells to generate electricity for heating elements equipped with graphene heating belts can save energy while ensuring normal oil well production.

[0023] This invention utilizes all available thermal energy by manufacturing a flue heat exchanger. It also fully leverages the heat from the high-temperature exhaust gas of the denitrification unit to heat the heat transfer oil in the heat transfer oil pipes. The heat transfer oil in both the heating element and the heat exchanger's heat transfer oil pipes circulates through a heat transfer oil circulation pump, jointly heating the heat transfer oil and further reducing the heating cost of the oil well's produced fluids. This system boasts high heating efficiency, and during operation, a clearly observable disconnection point of 5-10cm or more is achieved using a double-throw switch, preventing power return to the grid and ensuring safety and reliability.

[0024] This system has the function of monitoring and controlling the temperature of heat transfer oil and oil well produced fluid. After installing a 4G remote control module, it can also realize telemetry, remote control and other functions.

[0025] In summary, this invention can improve the heating efficiency of oil well production fluids, save energy consumption, and reduce production costs, demonstrating significant effectiveness and application value. Attached Figure Description

[0026] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0027] Figure 1 This is a schematic diagram of the overall structure of the present invention.

[0028] Figure 2 for Figure 1 A schematic diagram of the internal structure of the heating element.

[0029] Figure 3 for Figure 2 A schematic diagram of the structure of the center outlet.

[0030] Figure 4 for Figure 2 A schematic diagram of the circuit connection of the graphene heating belt.

[0031] Figure 5 for Figure 1 A schematic diagram of the structure of the middle flue heat exchanger.

[0032] Figure 1 The components include: 1. Integrated control device; 2. Inlet / outlet oil temperature controller; 3. Thermal oil temperature controller; 4. Thermal oil level gauge; 5. Thermal oil heating power supply; 6. AC neutral wire; 7. Thermal oil circulation pump; 8. Heating element; 9. Rectifier; 10. Refrigerated dryer; 11. Skid-mounted base; 12. Three-phase AC power supply; 13. Three-phase power switch; 14. Double-throw switch; 15. Single-phase control switch; 16. Generator switch; 17. Generator AC power supply; 18. Generator; 19. Flue heat exchanger; 20. Denitrification device; 21. Natural gas engine; 22. Engine intake pipeline; 23. Electric regulating valve; 24. Gas flow meter; 25. Gas-liquid separator; 26. Filter; 27. Programmable Logic Controller (PLC).

[0033] Figure 2 - Figure 5 In the middle section: Oil well production fluid inlet 8-1, oil outlet temperature sensor port 8-2, oil well production fluid inlet / outlet end plate 8-3, heating shell 8-4, heat transfer oil 8-5, heat transfer oil pipe 8-6, graphene heating belt 8-7, graphene heating belt one 8-7-1, graphene heating belt two 8-7-2, graphene heating belt three 8-7-3, oil well production fluid 8-8, heat transfer oil inlet / outlet end plate 8-9, high-strength sealant 8-10, cable outlet 8-11. 8-12, heat transfer oil filling port, 8-13, heat transfer oil pipe outlet, 8-14, oil well production fluid outlet, 8-15, oil inlet temperature sensor, 8-16, heat transfer oil pipe inlet, 8-17, heat transfer oil temperature sensor, 8-18, heat transfer oil level sensor, 8-19, flue gas discharge port, 19-1, heat exchanger heat transfer oil outlet, 19-2, heat exchanger heat transfer oil inlet, 19-3, heat transfer oil heating pipe, 19-4, flue gas inlet port, 19-5. Detailed Implementation

[0034] The accompanying drawings are for reference and illustration only and are not intended to limit the scope of protection of this invention. The technical solutions of the embodiments of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this invention, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0036] In the description of this invention, it should be understood that the terms "length," "width," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships, are based on the orientation or positional relationships shown in the accompanying drawings and are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. Furthermore, in the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified.

[0037] See Figure 1 - Figure 2 The heating system for heating oil well produced fluid using associated gas generated from oil wells includes a natural gas generator set. The heating element 8 has a heating shell 8-4 and a heat transfer oil pipe 8-6 containing heat transfer oil 8-5. The heat transfer oil pipe 8-6 is installed in the heating shell 8-4. The oil well produced fluid 8-8 enters the heating shell 8-4 from the oil well produced fluid inlet 8-1 and flows into the crude oil export pipeline from the oil well produced fluid outlet 8-14. The integrated control device 1 is divided into a control section and an AC section. The control section includes a rectifier 9, a PLC, an inlet / outlet oil temperature controller 2, a heat transfer oil temperature controller 3, and a heat transfer oil level gauge 4. The power source is electricity. The three-phase AC power supply 12 of the grid is electrically connected to the inlet / outlet oil temperature controller 2, the thermal oil temperature controller 3, and the thermal oil level gauge 4 via rectifier 9; the inlet / outlet oil temperature controller 2 is electrically connected to the outlet oil temperature sensor 8-2 and the inlet oil temperature sensor 8-15 installed in the heating element 8 via signal cables; the signal cables of the thermal oil temperature controller 3 and the thermal oil level gauge 4 are electrically connected to the thermal oil temperature sensor 8-18 and the thermal oil level sensor 8-19 installed in the thermal oil pipe 8-6, respectively; and the signal cables of the inlet / outlet oil temperature controller 2, the thermal oil temperature controller 3, and the thermal oil level gauge 4 are electrically connected to the PLC. Figure 1 The part below the dashed box in the integrated control device 1 is the AC section, which includes a generator switch 16 and a double-throw switch 14. 、A three-phase power switch 13 and a single-phase control switch 15 are provided. The single-phase control switch 15 has three phases, each electrically connected to one of the three phases from the double-throw switch 14. The double-throw switch 14 is installed between the power output terminal of the three-phase power switch 13 and the power output terminal of the generator switch 16. The double-throw switch 14 is sequentially electrically connected to the input terminals of the single-phase control switch 15 and the heat transfer oil heating power supply 5. The single-phase control switch 15 is electrically connected to the PLC in the control section via a signal cable. The associated gas generated during the oil well production process is separated into liquids by the gas-liquid separator 25, and then passes through the refrigerated dryer 10 and the engine intake pipeline 22 into the natural gas generator set. It generates electricity through the natural gas engine 21 and the generator 18. The generator AC power 17 generated by the generator 18 is used to heat the heat transfer oil 8-5 in the heat transfer oil pipe 8-6 via the generator switch 16 and the double-throw switch 14. In the case of insufficient associated gas, the heat transfer oil 8-5 is heated by using the three-phase AC power 12 of the power grid through the double-throw switch 14. The associated gas generated during the oil well production process is separated into liquids by a gas-liquid separator 25 and then dried by a refrigerated dryer 10 before entering the natural gas generator set, ensuring the safe operation of the natural gas generator set. The programmable logic editor (PLC) can be ordered from the manufacturer as needed.

[0038] Currently, natural gas generator sets using associated gas are mainly used to generate electricity for the power grid. This invention uses the electricity generated by the natural gas generator set using associated gas to directly heat the produced fluids in the oil well. This fully utilizes energy while reducing the processes and steps involved in generating and using electricity from the natural gas generator set. Current natural gas generator sets generally include a natural gas engine 21, a denitrification device 20, and a generator 18. The power output of the natural gas engine 21 is connected to the power input of the generator 18. The denitrification device 20 is connected to the exhaust pipe of the natural gas engine 21, denitrifying the flue gas before it is discharged into the atmosphere. The associated gas produced in the oil well is first separated by a gas-liquid separator 25 before entering the natural gas generator set.

[0039] Based on the above embodiment one, the present invention also has the following embodiments.

[0040] A preferred embodiment: See Figure 1 and Figure 5 A flue heat exchanger 19 is installed at the outlet of the flue gas duct of the denitrification device 20 in the natural gas generator set. A heat transfer oil circulation pump 7 is connected in series in the heat transfer oil pipeline between the heat transfer oil inlet 8-17 of the heat transfer oil pipe 8-6 and the heat transfer oil outlet 19-2 of the heat exchanger of the flue heat exchanger 19.

[0041] To better utilize the heat from the exhaust gas of the natural gas engine 21, this invention installs a flue gas heat exchanger 19 at the exhaust pipe outlet of the denitrification device 20. This allows the heat transfer oil 8-5 in the heat transfer oil pipe 8-6 to exchange heat in the flue gas heat exchanger 19. After the heat from the exhaust gas of the natural gas engine 21 is fully utilized, it is then discharged into the atmosphere through the flue gas heat exchanger 19. This invention not only directly applies the associated gas generated during oil well production to the heating of the oil well's produced fluid via a natural gas generator set, but also further saves electrical energy through the use of the flue gas heat exchanger 19.

[0042] In a preferred embodiment: the flue heat exchanger 19 is provided with a heat exchanger heat transfer oil outlet 19-2, a heat exchanger heat transfer oil inlet 19-3, a heat transfer oil heating tube 19-4, a flue gas inlet 19-5, and a flue gas outlet 19-1; the two ends of the heat transfer oil heating tube 19-4, installed in the flue heat exchanger shell, are respectively connected to the heat exchanger heat transfer oil outlet 19-2 and the heat exchanger heat transfer oil inlet 19-3; the exhaust pipe outlet of the denitrification device 20 is connected to the flue gas inlet 19-5; the heat transfer oil inlet 8-17 and the heat transfer oil outlet 8-13 of the heat transfer oil tube 8-6 are respectively connected to the heat exchanger heat transfer oil outlet 19-2 and the heat exchanger heat transfer oil inlet 19-3 via heat transfer oil pipelines; the heat transfer oil heating tube 19-4 is a coil with metal fins on its outer wall. The metal fins increase the heat exchange area and improve the heat exchange effect. High-temperature flue gas from the exhaust pipe of the denitrification unit 20 enters through the flue gas inlet 19-5 of the flue heat exchanger 19, heats the heat transfer oil in the heat transfer oil heating pipe 19-4 in the heat exchanger shell, and then is discharged into the atmosphere through the exhaust port 19-1. This can make full use of the high-temperature flue gas in the exhaust pipe of the natural gas engine 21, and further save energy.

[0043] A preferred embodiment: See Figure 2 - Figure 4 The heat-conducting oil pipe 8-6 is a U-shaped pipe or a U-shaped pipe. Graphene heating strips 8-7 are also installed in the heat-conducting oil pipe 8-6. There are three graphene heating strips 8-7: graphene heating strip one 8-7-1, graphene heating strip two 8-7-2, and graphene heating strip three 8-7-3. The three phase lines A, B, and C of the AC power input terminal of the heat-conducting oil heating power supply 5 are electrically connected to one end of graphene heating strip one 8-7-1, graphene heating strip two 8-7-2, and graphene heating strip three 8-7-3, respectively. The other ends of graphene heating strip one 8-7-1, graphene heating strip two 8-7-2, and graphene heating strip three 8-7-3 are all electrically connected to the AC neutral line 6 of the input terminal of the heat-conducting oil heating power supply 5. Graphene has excellent electrothermal properties. Placing graphene in the heat transfer oil pipe 8-6 can significantly improve the heating efficiency of the heat transfer oil, enhance the heating effect of the oil well production fluid, and save electricity.

[0044] In a preferred embodiment: the heating shell 8-4 of the heating body 8 is welded to an oil well fluid inlet / outlet end plate 8-3 and a heat transfer oil inlet / outlet end plate 8-9 at both ends, and the heat transfer oil pipe 8-6 is connected to a heat transfer oil pipe outlet 8-13 and a heat transfer oil pipe inlet 8-17 at both ends, respectively. The heat transfer oil pipe outlet 8-13 and the heat transfer oil pipe inlet 8-17 are located outside the heat transfer oil inlet / outlet end plate 8-9 at one end of the heating shell 8-4; the oil well fluid inlet 8-1 and the oil well fluid outlet 8-14 are located outside the oil well fluid inlet / outlet end plate 8-3 of the heating shell 8-4.

[0045] In a preferred embodiment: An outlet 8-11 and an inlet 8-16 are respectively provided in the rear pipe body of the heat transfer oil pipe outlet 8-13 and heat transfer oil pipe inlet 8-17. One end of the graphene heating strip 1 8-7-1, graphene heating strip 2 8-7-2, and graphene heating strip 3 8-7-3 is led out from the outlet 8-11 and electrically connected to the three phase lines A, B, and C of the AC power input terminal of the heat transfer oil heating power supply 5. The other end of the graphene heating strip 1 8-7-1, graphene heating strip 2 8-7-2, and graphene heating strip 3 8-7-3 is led out from the inlet 8-16 and electrically connected to the AC neutral line 6 of the heat transfer oil heating power supply 5. High-strength sealant 8-10 is filled between the outlet 8-11 and inlet 8-16 and the graphene heating strip 8-7 to ensure a sealing effect.

[0046] In a preferred embodiment: the inlet oil temperature sensor 8-15 and the outlet oil temperature sensor 8-2 are respectively installed in the test ports of the oil well production fluid inlet 8-1 and the oil well production fluid outlet 8-14; the thermal oil temperature sensor 8-18 and the thermal oil level sensor 8-19 are installed in the outlet port 8-11 of the thermal oil pipe 8-6 and sealed with high-strength sealant 8-10 between them; the thermal oil temperature controller 3 and the thermal oil level sensor 4 are electrically connected to the thermal oil temperature sensor 8-18 and the thermal oil level sensor 8-19 via signal cables.

[0047] In a preferred embodiment: the heat transfer oil pipe outlet 8-13 is located at the upper part of the heating shell 8-4, and a heat transfer oil filling port 8-12 is provided in the pipe body in front of the outlet 8-11 in the heat transfer oil pipe outlet 8-13. When the liquid level of heat transfer oil 8-5 in the heat transfer oil pipe 8-6 is insufficient, it can be added from the heat transfer oil filling port 8-12.

[0048] In a preferred embodiment: a filter 26 is connected in series between the gas supply line of the associated gas and the gas-liquid separator 25; a gas flow meter 24 and an electric regulating valve 23 are also connected in series in the engine intake line 22 between the refrigerated dryer 10 and the natural gas generator set; the electric regulating valve 23 is electrically connected to the PLC in the control section of the integrated control device 1 via a signal cable. The filter 26 removes impurities from the associated gas before it enters the gas-liquid separator 25, improving the separation effect of the gas-liquid separator 25; the refrigerated dryer 10 removes moisture from the gas separated by the gas-liquid separator 25; the gas flow meter 24 connected in series in the engine intake line 22 measures the amount of associated gas, and the electric regulating valve 23 controls the supply and quantity of associated gas.

[0049] In a preferred embodiment, a 4G remote control module can also be installed in the integrated control device 1. This 4G remote control module is electrically connected to the PLC and can wirelessly connect to the operator's mobile phone. The double-throw switch 14, connected to the generator AC power supply 17 or the three-phase AC power supply 12, is spaced 5cm-10cm away from the off-line side of the three-phase AC power supply 12 or the generator AC power supply 17. When the system uses associated gas for power generation, the double-throw switch 14 is switched on the generator AC power supply 17 side; when associated gas power generation is not possible, the double-throw switch 14 is switched on the three-phase AC power supply 12 side. Both sides of the double-throw switch 14 cannot be switched simultaneously, and there is a clear 5cm-10cm disconnection distance on the off-line side of the double-throw switch 14. This ensures that the electricity generated using associated gas does not return to the grid and also ensures the safety of the natural gas generator set and grid maintenance personnel. The electrical energy at the output of the dual-throw switch is only electrically connected to the graphene heating belt 8-7. Other components in the integrated control device 1 and other equipment in this system, such as the refrigerated dryer 10, gas-liquid separator 25, gas flow meter 24, electric regulating valve 23 and heat transfer oil circulation pump 7, are all powered by the AC power supply 12 of the generator from the power grid, ensuring that the system of this invention can be used normally when the natural gas generator set is not generating electricity.

[0050] The 4G remote control module installed in the integrated control unit 1 can monitor and control the operation of the system at the production site via a WeChat mini-program on a mobile phone through the existing communication network, without the need for on-site personnel. It can obtain information such as the temperature of the oil well's produced fluid 8-8 and heat transfer oil 8-5, the on / off signals of generator 18, and the shutdown alarm of generator 18, so as to facilitate well patrol personnel to go to the site in a timely manner for handling.

[0051] In a preferred embodiment: the surfaces of all components in contact with the oil well fluid in the associated gas power generation and oil well production system are chrome-plated. The outer surface of the heating element 8 is covered with insulation cotton to reduce heat loss. The generator 18 is designed with a voltage of 400V. The associated gas power generation and oil well production system is fixed on the skid-mounted base 11. The surfaces of the components in contact with the oil well fluid include the inner wall of the heating shell 8-4, the outer wall of the heat transfer oil pipe 8-6, the inner wall of the oil well production fluid outlet 8-14, and the inner wall of the oil well production fluid inlet 8-1. All of these components are chrome-plated for corrosion protection, ensuring that they are not corroded by the oil well production fluid and improving their service life. Fixing this heating system on the skid-mounted base 11 facilitates transportation and use on the oil well.

[0052] The heating element 8 in this system is a large-diameter pipe design. The oil well production fluid 8-8 enters the heating element 8 through the oil well production fluid inlet 8-1 at the bottom of the heating element 8 and flows out of the heating element 8 through the oil well production fluid outlet 8-14. One end of the graphene heating belt 1 8-7-1, graphene heating belt 2 8-7-2, and graphene heating belt 3 8-7-3 installed in the heat transfer oil pipe 8-6 in the heating element 8 is led out through the outlet 8-11 and electrically connected to the three phase lines A, B, and C of the input terminal of the heat transfer oil heating power supply 5, respectively. The other end of the graphene heating belt 1 8-7-1, graphene heating belt 2 8-7-2, and graphene heating belt 3 8-7-3 is led out through the inlet 8-16 and electrically connected to the AC neutral line 6 of the input terminal of the heat transfer oil heating power supply 5. The heat transfer oil filling port 8-12 is used to add heat transfer oil 8-5. The oil outlet temperature sensor 8-2 and the oil inlet temperature sensor 8-15 transmit signals to the inlet and outlet oil temperature controller 2 on the integrated control device 1. The heat transfer oil temperature sensor 8-18 and the heat transfer oil level sensor 8-19 installed in the outlet port 8-11 of the heat transfer oil pipe 8-6 are connected to the heat transfer oil temperature controller 3 and the heat transfer oil level sensor 4 respectively via signal cables.

[0053] See Figure 4 When the heating element 8 is powered by the three-phase AC power supply 12 from the power grid or the AC power supply 17 from the generator, when the oil outlet temperature monitored by the oil inlet / outlet temperature controller 2 reaches the set upper limit, the integrated control device 1 can control the single-phase control switch 15 to disconnect the A-phase line, that is, the A-phase line in the single-phase control switch 15; after running for 30 minutes, if the oil outlet temperature monitored by the oil inlet / outlet temperature controller 2 continues to remain at the set upper limit, the integrated control device 1 controls the single-phase control switch 15 to disconnect the B-phase line. ；After 30 minutes of operation, if the oil outlet temperature monitored by the inlet / outlet oil temperature controller 2 continues to remain at the set upper limit, the integrated control device 1 controls the single-phase control switch 15 to disconnect the C-phase line; if the oil outlet temperature monitored by the inlet / outlet oil temperature controller 2 reaches the set lower limit, the integrated control device 1 controls the single-phase control switch 15 to close the C-phase line; if the oil outlet temperature monitored by the inlet / outlet oil temperature controller 2 continues to remain at the set lower limit, the integrated control device 1 controls the single-phase control switch 15 to close the B-phase line; if the oil outlet temperature monitored by the inlet / outlet oil temperature controller 2 continues to remain at the set lower limit, the integrated control device 1 controls the single-phase control switch 15 to close the A-phase line.

[0054] like Figure 1 As shown, in this invention, associated gas generated during the oil well production process is desulfurized in the wellbore and then enters the filter 26, gas-liquid separator 25, and refrigerated dryer 10 through the associated gas inlet pipeline. The refrigerated dryer 10 removes moisture from the associated gas, which then flows through a gas flow meter 24, an electric regulating valve 23, and an engine intake pipeline 22 into a natural gas engine 21 to drive a generator 18 to generate electricity. A denitrification device 20, connected in sequence to the exhaust pipe of the natural gas engine 21, ensures that the associated gas meets environmental protection standards. The flue gas heat exchanger 19 in this invention further reuses the high-temperature flue gas discharged from the exhaust pipe of the denitrification device 20 to heat the heat transfer oil 8-5, further saving energy.

[0055] When the associated gas source is sufficient, the system of this invention can disconnect the three-phase power switch 13 through the integrated control device 1, switch the double-throw switch 14 to the generator AC power supply 17 on the generator side of the generator 18, close the generator switch 16, and start the natural gas engine 21 to drive the generator 18 to generate electricity. The generator 18 is designed with a voltage of 400V and can heat the oil well production fluid 8-8 through graphene heating belt 1 (8-7-1), graphene heating belt 2 (8-7-2), and graphene heating belt 3 (8-7-3).

[0056] The embodiments described above are merely typical examples, but the present invention is not limited to these embodiments. Those skilled in the art can make modifications without departing from the spirit and teachings of the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the inventive spirit and concept of the present invention should be included within the protection scope of the present invention. Therefore, the protection scope is not limited to the above description.

Claims

1. A heating system that uses associated gas from oil wells to generate electricity for heating the produced fluids in oil wells, including a natural gas generator set, characterized in that, The heating element (8) is equipped with a heating shell (8-4) and a heat transfer oil pipe (8-6) containing heat transfer oil (8-5). The heat transfer oil pipe (8-6) is installed in the heating shell (8-4). The oil well production fluid (8-8) enters the heating shell (8-4) from the oil well production fluid inlet (8-1) and flows into the crude oil export pipeline from the oil well production fluid outlet (8-14). The integrated control device (1) is divided into a control section and an AC section. The control section is equipped with a rectifier (9), a PLC, an inlet and outlet oil temperature controller (2), a heat transfer oil temperature controller (3), and a heat transfer oil level gauge (4). The three-phase AC power supply (12) from the power grid is rectified by the rectifier (9) and connected to the inlet and outlet oil temperature controller (2), the heat transfer oil level gauge (3), and the heat transfer oil level gauge (4). The hot oil temperature controller (3) and the thermal oil level gauge (4) are electrically connected; the inlet and outlet oil temperature controller (2) is electrically connected to the outlet oil temperature sensor (8-2) and the inlet oil temperature sensor (8-15) installed in the heating body (8) via signal cables; the signal cables of the thermal oil temperature controller (3) and the thermal oil level gauge (4) are electrically connected to the thermal oil temperature sensor (8-18) and the thermal oil level sensor (8-19) installed in the thermal oil pipe (8-6), respectively; the signal cables of the inlet and outlet oil temperature controller (2), the thermal oil temperature controller (3), and the thermal oil level gauge (4) are electrically connected to the PLC; the AC section is equipped with a generator switch (16) and a double-throw switch (14). 、 A three-phase power switch (13) and a single-phase control switch (15) are provided. The single-phase control switch (15) has three phases, each electrically connected to one of the three phases from a double-throw switch (14). The double-throw switch (14) is installed between the power output terminal of the three-phase power switch (13) and the power output terminal of the generator switch (16). The double-throw switch (14) is electrically connected in sequence to the input terminals of the single-phase control switch (15) and the heat transfer oil heating power supply (5). The single-phase control switch (15) is electrically connected to the PLC in the control section via a signal cable. The oil well production process generates The associated gas is separated into liquids by a gas-liquid separator (25), and then enters the natural gas generator set through a refrigerated dryer (10) and an engine intake line (22). It generates electricity through a natural gas engine (21) and a generator (18). The AC power (17) generated by the generator (18) is used to heat the heat transfer oil (8-5) in the heat transfer oil pipe (8-6) through a generator switch (16) and a double-throw switch (14). In the case of insufficient associated gas, the heat transfer oil (8-5) is heated by using the three-phase AC power (12) of the power grid through the double-throw switch (14).

2. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 1, characterized in that, in A flue heat exchanger (19) is installed at the outlet of the flue gas duct of the denitrification device (20) in the natural gas generator set. A heat transfer oil circulation pump (7) is connected in series in the heat transfer oil pipeline between the heat transfer oil inlet (8-17) of the heat transfer oil pipe (8-6) and the heat transfer oil outlet (19-2) of the heat exchanger of the flue heat exchanger (19).

3. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 2, characterized in that, The flue heat exchanger (19) is provided with a heat exchanger heat transfer oil outlet (19-2), a heat exchanger heat transfer oil inlet (19-3), a heat transfer oil heating tube (19-4), a flue gas inlet (19-5), and a flue gas outlet (19-1); the two ends of the heat transfer oil heating tube (19-4) installed in the flue heat exchanger shell are respectively connected to the heat exchanger heat transfer oil outlet (19-2) and the heat exchanger heat transfer oil inlet (19-3), and the exhaust pipe outlet of the denitrification device (20) is connected to the flue gas inlet (19-5); the heat transfer oil inlet (8-17) and the heat transfer oil outlet (8-13) of the heat transfer oil tube (8-6) are respectively connected to the heat exchanger heat transfer oil outlet (19-2) and the heat exchanger heat transfer oil inlet (19-3) through heat transfer oil pipelines; the heat transfer oil heating tube (19-4) is a coil and the outer wall of the coil is provided with metal fins.

4. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 1 or 2, characterized in that, The heat-conducting oil pipe (8-6) is a U-shaped pipe or a U-shaped pipe. Graphene heating belts (8-7) are also installed in the heat-conducting oil pipe (8-6). There are three graphene heating belts (8-7): graphene heating belt one (8-7-1), graphene heating belt two (8-7-2), and graphene heating belt three (8-7-3). The three phase lines A, B, and C of the AC power input terminal of the heat-conducting oil heating power supply (5) are electrically connected to one end of graphene heating belt one (8-7-1), graphene heating belt two (8-7-2), and graphene heating belt three (8-7-3), respectively. The other end of graphene heating belt one (8-7-1), graphene heating belt two (8-7-2), and graphene heating belt three (8-7-3) are all electrically connected to the AC neutral line (6) of the input terminal of the heat-conducting oil heating power supply (5).

5. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 4, characterized in that, The heating shell (8-4) of the heating body (8) has an oil well fluid inlet / outlet end plate (8-3) and a heat transfer oil inlet / outlet end plate (8-9) welded to both ends. The heat transfer oil pipe (8-6) has a heat transfer oil pipe outlet (8-13) and a heat transfer oil pipe inlet (8-17) at both ends. The heat transfer oil pipe outlet (8-13) and the heat transfer oil pipe inlet (8-17) are located outside the heat transfer oil inlet / outlet end plate (8-9) at one end of the heating shell (8-4). The oil well fluid inlet (8-1) and the oil well fluid outlet (8-14) are located outside the oil well fluid inlet / outlet end plate (8-3) of the heating shell (8-4).

6. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 5, characterized in that, in The outlet (8-13) and inlet (8-17) of the heat transfer oil pipe are respectively provided with an outlet (8-11) and an inlet (8-16) in the rear pipe body. One end of the graphene heating belt one (8-7-1), graphene heating belt two (8-7-2), and graphene heating belt three (8-7-3) is led out from the outlet (8-11) and connected to the three phase wires A, B, and C of the AC power input terminal of the heat transfer oil heating power supply (5). Electrical connection; the other ends of the graphene heating band one (8-7-1), graphene heating band two (8-7-2) and graphene heating band three (8-7-3) are led out from the inlet (8-16) and electrically connected to the AC neutral line (6) of the input terminal of the heat transfer oil heating power supply (5); high-strength sealant (8-10) is filled between the outlet (8-11) and the inlet (8-16) and the graphene heating band (8-7).

7. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 6, characterized in that, The inlet temperature sensor (8-15) and outlet temperature sensor (8-2) are respectively installed in the test ports of the oil well production fluid inlet (8-1) and the oil well production fluid outlet (8-14); the thermal oil temperature sensor (8-18) and the thermal oil level sensor (8-19) are installed in the outlet (8-11) of the thermal oil pipe (8-6) and sealed with high-strength sealant (8-10) between them; the thermal oil temperature controller (3) and the thermal oil level meter (4) are electrically connected to the thermal oil temperature sensor (8-18) and the thermal oil level sensor (8-19) respectively through signal cables.

8. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 6, characterized in that, The heat transfer oil outlet (8-13) is located at the upper part of the heating shell (8-4), and the heat transfer oil filling port (8-12) is provided in the pipe body in front of the outlet (8-11) in the heat transfer oil outlet (8-13).

9. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 2, characterized in that, A filter (26) is connected in series between the gas pipeline for the associated gas and the gas-liquid separator (25). A gas flow meter (24) and an electric regulating valve (23) are also connected in series in the engine intake pipeline (22) between the refrigerated dryer (10) and the natural gas generator set. The electric regulating valve (23) is electrically connected to the PLC in the control section of the integrated control device (1) via a signal cable.

10. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 4, characterized in that, in The integrated control device (1) can also be equipped with a 4G remote control module. The 4G remote control module is electrically connected to the PLC and can be wirelessly connected to the operator's mobile phone. The double-throw switch (14) connected to the generator AC power supply (17) or the three-phase AC power supply (12) is 5cm-10cm away from the off side of the three-phase AC power supply (12) or the generator AC power supply (17).

11. The heating system for heating oil well produced fluids using associated gas generated from oil wells as described in claim 5, characterized in that, The surfaces of all components in contact with the oil well fluid in the associated gas power generation heating system are chrome-plated, and the outer surface of the heating body (8) is covered with insulation cotton for heat preservation. The design voltage of the generator (18) is 400V, and the associated gas power generation heating system for oil well fluid is fixed on the skid-mounted base (11).

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