A carbon dioxide fracturing ground pipeline heating device and temperature control system

Abstract

The application provides a ground pipeline heating device and temperature control system for carbon dioxide fracturing, the heating device comprises a high-pressure pipeline heating device and a low-pressure pipeline heating device, wherein the high-pressure pipeline heating device comprises an electromagnetic heater; the low-pressure pipeline heating device comprises a U-shaped tubular electric heating element. The temperature control system for carbon dioxide fracturing comprises a CO2 storage tank, a CO2 booster pry and a fracturing pump truck connected in sequence through pipelines, and the ground pipeline heating device. The heating device has the advantages of precise heating, fast reaction speed, real-time monitoring of CO2 temperature, and the like, and can start / stop the electric heating device through an electric control cabinet. The heating device can be remotely controlled by a mobile phone program when the mobile phone is in WIFI mode, and is safe and reliable in operation, and can automatically alarm when the temperature is too high.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas field exploration and development, and is applicable to heating liquid CO2 during the CO2 fracturing stage of oil and gas wells to increase the temperature of liquid CO2 inside the pressure pipeline. Specifically, it relates to a surface pipeline heating device and temperature control system for carbon dioxide fracturing. Background Technology

[0002] Currently, carbon dioxide fracturing in China has not yet implemented actual carbon dioxide ground pipeline heating under real-world operating conditions. A review of literature and patents reveals relevant papers and invention patents, but there are no reports of practical applications.

[0003] The purpose of this invention is to protect the surface pipeline heating technology for carbon dioxide fracturing, and to achieve phase conversion of carbon dioxide in the wellbore by real-time control of the temperature of liquid carbon dioxide in high and low pressure pipelines. Summary of the Invention

[0004] The purpose of this invention is to address at least one of the aforementioned deficiencies in the prior art. For example, one objective of this invention is to provide a ground pipeline heating device for carbon dioxide fracturing; another objective of this invention is to provide a temperature control system for carbon dioxide fracturing.

[0005] To achieve the above objectives, the present invention provides a ground pipeline heating device for carbon dioxide fracturing, the heating device comprising a high-pressure pipeline heating device and a low-pressure pipeline heating device, wherein the high-pressure pipeline heating device comprises an electromagnetic heater; and the low-pressure pipeline heating device comprises a U-shaped tubular electric heating element.

[0006] Alternatively, the high-pressure pipeline heating device uses an electromagnetic heater, which consists of an electromagnetic heating controller and an induction heating coil.

[0007] Alternatively, the high-pressure pipeline heating device can achieve real-time control of the outlet temperature by installing an electromagnetic coil and a temperature sensor outside the high-pressure pipeline and using a temperature control system.

[0008] Alternatively, the electromagnetic heater is a device that converts electrical energy into heat energy using the principle of electromagnetic heating; the high-pressure pipeline has a pipe thickness of no more than 8mm, is made of carbon steel, uses liquid CO2 as the heating medium, and has an output displacement of 0.6-1.0m³ per unit fracturing pump truck. 3 The pressure is increased by 0.5 min to heat the liquid in the pipeline to 30°C. An electromagnetic coil is uniformly wound on the high-pressure pipeline. The electromagnetic coil is made of silicone. An explosion-proof electromagnetic controller and an explosion-proof control box are installed. The control, display and operation of the heater are all operated on the explosion-proof control box.

[0009] Alternatively, the low-pressure pipeline heating device consists of a U-shaped tubular electric heating element, a body, and a control system. The U-shaped tubular electric heating element is made by placing a high-temperature resistance wire inside a metal tube and tightly filling the gaps with crystalline magnesium oxide powder with good insulation and thermal conductivity. Using the tubular electric heating element as the heating element and installing a flow guide baffle inside the cylinder can make the gas heat up evenly during flow.

[0010] Alternatively, the low-pressure pipeline heating device uses a digital display temperature controller, a power regulator, and a temperature measuring element to form a measurement, regulation, and control loop. During the electric heating process, the temperature measuring element sends the electrical signal of the heating device outlet temperature to the digital display temperature controller for amplification, comparison, and display of the measured temperature value. At the same time, it outputs a signal to the input terminal of the solid-state relay to control the heating device, thereby giving the control cabinet good control accuracy and regulation characteristics.

[0011] Alternatively, the high-pressure pipeline heating device and the low-pressure pipeline heating device can be operated independently or used in series. The two devices are connected to the temperature control system via wires and can be controlled remotely and locally to achieve local data storage and remote monitoring.

[0012] Another aspect of the present invention provides a temperature control system for carbon dioxide fracturing, the system comprising: a CO2 storage tank, a CO2 pressurization skid and a fracturing pump truck connected in sequence by pipelines, and the aforementioned heating device.

[0013] Optionally, the system further includes a CO2 temperature and data acquisition and monitoring system unit, wherein the detection unit is equipped with an explosion-proof control system for a high-pressure pipeline heating device and a low-pressure pipeline heating device;

[0014] The explosion-proof control system for the high-pressure pipeline heating device includes one over-temperature protection point for each electromagnetic coil, one temperature display point at the pipeline inlet, and one temperature control point at the outlet, totaling multiple temperature points with a temperature control accuracy of ±1℃.

[0015] Alternatively, the CO2 storage tank, CO2 booster skid, fracturing pump truck, and heating device are all connected by low-temperature resistant stainless steel braided pipelines.

[0016] Alternatively, the CO2 storage tank is used to store liquid CO2 at a storage temperature of -20 to -25°C.

[0017] Alternatively, the CO2 booster skid draws CO2 from the CO2 storage tank and supplies it to the fracturing truck via a low-pressure pipeline.

[0018] Alternatively, the low-pressure pipeline heating device heats the CO2 in the low-pressure pipeline by connecting a dedicated pipeline heater, thereby raising the CO2 temperature, but not exceeding -15 to -10°C.

[0019] Alternatively, the fracturing pump truck can deliver heated liquid CO2 to the oil and gas well via a high-pressure pipeline.

[0020] Compared with the prior art, the beneficial effects of the present invention include at least one of the following:

[0021] (1) The heating device of the present invention can realize the phase conversion of carbon dioxide in the well barrel by real-time control of the temperature of liquid carbon dioxide in the high and low pressure pipelines.

[0022] (2) The heating device of the present invention has the advantages of precise heating, fast response speed, and the ability to start / stop the electric heating device through the electrical control cabinet while monitoring the CO2 temperature in real time.

[0023] (3) The heating device of the present invention is designed for CO2 fracturing construction sites in oil fields. It can be remotely controlled by a mobile phone program when in WIFI mobile phone mode. It is safe and reliable to operate and can automatically alarm for over-temperature. Attached Figure Description

[0024] The above and other objects and / or features of the present invention will become clearer from the following description taken in conjunction with the accompanying drawings, in which:

[0025] Figure 1 A schematic diagram of the connection of the ground pipeline heating device for carbon dioxide fracturing according to the present invention is shown.

[0026] Figure 2 A schematic diagram of the circulation of the high-pressure pipeline heating device of the present invention is shown.

[0027] Figure 3 A schematic diagram of the circulation of the low-pressure pipeline heating device of the heating device of the present invention is shown.

[0028] Explanation of key figure labels:

[0029] 1-CO2 storage tank; 2-CO2 booster skid; 3-Low-pressure pipeline heating device; 31-Pipeline heater; 32-Heat-using equipment; 4-Fracturing pump truck; 5-High-pressure pipeline heating device; 51-High-pressure pipeline electromagnetic coil; 52-Temperature control system; 6-Oil and gas wellhead;

[0030] a1 - First low-pressure pipeline, a2 - Second low-pressure pipeline, a3 - Third low-pressure pipeline;

[0031] b1 - First high-pressure pipeline, b2 - Second high-pressure pipeline. Detailed Implementation

[0032] In the following description, a ground pipeline heating device and temperature control system for carbon dioxide fracturing according to the present invention will be explained in detail with reference to exemplary embodiments.

[0033] This invention designs two heating devices. The high-pressure pipeline on the ground is heated by an electromagnetic heater, while the low-pressure pipeline is heated by a U-shaped tubular electric heating element with a high-temperature resistance wire placed inside a metal tube and an external resistance wire, which assists in heating the liquid CO2 from the outside of the pipeline, thereby increasing the temperature of the liquid CO2 inside the pressure pipeline.

[0034] Exemplary Example 1

[0035] This exemplary embodiment provides a ground pipeline heating device for carbon dioxide fracturing. The heating device includes a high-pressure pipeline heating device and a low-pressure pipeline heating device. The high-pressure pipeline heating device includes an electromagnetic heater, and the low-pressure pipeline heating device includes a U-shaped tubular electric heating element.

[0036] In this embodiment, the high-pressure pipeline heating device uses an electromagnetic heater, which consists of an electromagnetic heating controller and an induction heating coil.

[0037] In this embodiment, as Figure 1 As shown, the high-pressure pipeline heating device achieves real-time control of the outlet temperature by installing an electromagnetic coil and a temperature sensor on the outside of the high-pressure pipeline and using a temperature control system.

[0038] In this embodiment, the electromagnetic heater is a device that converts electrical energy into heat energy using the principle of electromagnetic heating; the high-pressure pipeline has a pipe thickness of no more than 8mm, is made of carbon steel, uses liquid CO2 as the heating medium, and has an output displacement of 0.6-1.0m³ per unit of fracturing pump truck. 3 The pressure is increased by 0.5 min to heat the liquid in the pipeline to 30°C. An electromagnetic coil is uniformly wound on the high-pressure pipeline. The electromagnetic coil is made of silicone. An explosion-proof electromagnetic controller and an explosion-proof control box are installed. The control, display and operation of the heater are all operated on the explosion-proof control box.

[0039] In this embodiment, the low-pressure pipeline heating device consists of a U-shaped tubular electric heating element, a body, and a control system. The U-shaped tubular electric heating element is made by placing a high-temperature resistance wire inside a metal tube and tightly filling the gaps with crystalline magnesium oxide powder with good insulation and thermal conductivity. Using the tubular electric heating element as the heating element and installing a flow guide baffle inside the cylinder can make the gas heat up evenly during flow.

[0040] In this embodiment, as Figure 2As shown, the low-pressure pipeline heating device uses a digital display temperature regulator, a power regulator, and a temperature measuring element to form a measurement, regulation, and control loop. During the electric heating process, the temperature measuring element sends the electrical signal of the heating device outlet temperature to the digital display temperature regulator for amplification, comparison, and display of the measured temperature value. At the same time, it outputs a signal to the input terminal of the solid-state relay to control the heating device, thereby giving the control cabinet good control accuracy and regulation characteristics.

[0041] In this embodiment, the high-pressure pipeline heating device and the low-pressure pipeline heating device can operate independently or be used in series. The two devices are connected to the temperature control system via wires and can be controlled remotely and locally to achieve local data storage and remote monitoring.

[0042] Exemplary Example 2

[0043] This exemplary embodiment provides a temperature control system for carbon dioxide fracturing, such as Figure 1 As shown, the system includes: a CO2 storage tank 1 connected to a CO2 booster skid 2 via a first low-pressure pipeline a1; a CO2 booster skid 2 connected to a low-pressure pipeline heating device 3 via a second low-pressure pipeline a2; a low-pressure pipeline heating device 3 connected to a fracturing pump truck 4 via a third low-pressure pipeline a3; a fracturing pump truck 4 connected to a high-pressure pipeline heating device 5 via a first high-pressure pipeline b1; and a high-pressure pipeline heating device 5 connected to an oil and gas wellhead 6 via a second high-pressure pipeline b2.

[0044] In this embodiment, the system further includes a CO2 temperature and data acquisition and monitoring system unit, which is equipped with a high-pressure pipeline heating device and a low-pressure pipeline heating device explosion-proof control system.

[0045] The explosion-proof control system for the high-pressure pipeline heating device has one over-temperature protection point for each electromagnetic coil, one temperature display point at the pipeline inlet, and one temperature control point at the outlet, totaling multiple temperature points with a temperature control accuracy of ±5℃; the explosion-proof control system for the high-pressure pipeline heating device has a temperature control accuracy of ±3℃.

[0046] In this embodiment, the CO2 storage tank, CO2 booster skid, fracturing pump truck, and heating device are all connected by low-temperature resistant stainless steel braided pipelines.

[0047] In this embodiment, the CO2 storage tank is used to store liquid CO2 at a storage temperature of -20 to -25°C.

[0048] In this embodiment, the CO2 booster skid draws CO2 from the CO2 storage tank and supplies it to the fracturing truck through a low-pressure pipeline.

[0049] In this embodiment, the low-pressure pipeline heating device heats the CO2 in the low-pressure pipeline by connecting a dedicated pipeline heater, thereby raising the CO2 temperature, but not exceeding -15 to -10°C.

[0050] In this embodiment, the fracturing pump truck delivers heated liquid CO2 to the oil and gas well via a high-pressure pipeline.

[0051] To better understand the exemplary embodiments described above, further explanation is provided below with specific examples.

[0052] Example

[0053] The features of a ground pipeline heating device for carbon dioxide fracturing are:

[0054] Step 1, as follows Figure 2 As shown, the high-pressure pipeline electromagnetic coil 51 is wound around the outside of the high-pressure pipeline and connected to the temperature control system 52, so that the fracturing pump truck 4 is connected to the above-mentioned device through the high-pressure pipeline, and connected in numerical order and arrow direction.

[0055] Step 2, as follows Figure 3 As shown, the CO2 booster skid 2 is connected to the pipeline heater 31, and the pipeline heater 31 is connected to the heat-using equipment 32. The outlet of the heat-using equipment 32 is connected to the inlet of the pipeline heater 31, and the outlet of the pipeline heater 31 is connected to the inlet of the heat-using equipment 32. The heat is then supplied to the fracturing pump truck 4 through a low-pressure pipeline.

[0056] Step 3: After the connection is completed, the two sets of devices can operate independently or be used in series.

[0057] Step 4: The two devices are connected to the temperature control system via wires, enabling remote and local control, and achieving local data storage and remote monitoring.

[0058] Although the present invention has been described above in conjunction with exemplary embodiments and accompanying drawings, those skilled in the art should understand that various modifications can be made to the above embodiments without departing from the spirit and scope of the claims.

Claims

1. A ground pipeline heating device for carbon dioxide fracturing, characterized in that, The heating device includes a high-pressure pipeline heating device and a low-pressure pipeline heating device, wherein... High-pressure pipeline heating devices include electromagnetic heaters; The low-pressure pipeline heating device includes a U-shaped tubular electric heating element.

2. The surface pipeline heating device for carbon dioxide fracturing according to claim 1, characterized in that, The high-pressure pipeline heating device uses an electromagnetic heater, which consists of an electromagnetic heating controller and an induction heating coil.

3. The surface pipeline heating device for carbon dioxide fracturing according to claim 1, characterized in that, The high-pressure pipeline heating device achieves real-time control of the outlet temperature by installing an electromagnetic coil and a temperature sensor on the outside of the high-pressure pipeline and using a temperature control system.

4. The surface pipeline heating device for carbon dioxide fracturing according to claim 2, characterized in that, The electromagnetic heater is a device that converts electrical energy into heat energy using the principle of electromagnetic heating; the high-pressure pipeline has a pipe thickness of no more than 8mm, is made of carbon steel, uses liquid CO2 as the heating medium, and has an output displacement of 0.6-1.0m³ per unit of fracturing pump truck. 3 The pressure is increased by 0.5 min to heat the liquid in the pipeline to 30°C. An electromagnetic coil is uniformly wound on the high-pressure pipeline. The electromagnetic coil is made of silicone. An explosion-proof electromagnetic controller and an explosion-proof control box are installed. The control, display and operation of the heater are all operated on the explosion-proof control box.

5. The surface pipeline heating device for carbon dioxide fracturing according to claim 1, characterized in that, The low-pressure pipeline heating device consists of a U-shaped tubular electric heating element, a main body, and a control system. The U-shaped tubular electric heating element is made by placing a high-temperature resistance wire inside a metal tube and tightly filling the gaps with crystalline magnesium oxide powder with good insulation and thermal conductivity. Using the tubular electric heating element as the heating element and installing a flow guide baffle inside the cylinder can ensure that the gas is heated evenly during flow.

6. The surface pipeline heating device for carbon dioxide fracturing according to claim 1, characterized in that, The low-pressure pipeline heating device uses a digital display temperature controller, power regulator, and temperature measuring element to form a measurement, regulation, and control loop. During the electric heating process, the temperature measuring element sends the electrical signal of the heating device outlet temperature to the digital display temperature controller for amplification, comparison, and display of the measured temperature value. At the same time, it outputs a signal to the input terminal of the solid-state relay to control the heating device, thereby giving the control cabinet good control accuracy and regulation characteristics.

7. The surface pipeline heating device for carbon dioxide fracturing according to claim 1, characterized in that, The high-pressure pipeline heating device and the low-pressure pipeline heating device can be operated independently or used in series. The two devices are connected to the temperature control system by wires and can be controlled remotely and locally to achieve local data storage and remote monitoring.

8. A temperature control system for carbon dioxide fracturing, characterized in that, The system includes: a CO2 storage tank, a CO2 booster skid, and a fracturing pump truck connected in sequence by pipelines, and a heating device as described in any one of claims 1 to 7.

9. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The system also includes a CO2 temperature and data acquisition and monitoring system unit, which is equipped with an explosion-proof control system for a high-pressure pipeline heating device and a low-pressure pipeline heating device; wherein... The explosion-proof control system for high-pressure pipeline heating devices has one over-temperature protection point for each electromagnetic coil, one temperature display point at the pipeline inlet, and one temperature control point at the outlet, totaling multiple temperature points with a temperature control accuracy of ±1℃.

10. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The CO2 storage tank, CO2 booster skid, fracturing pump truck, and heating device are all connected by low-temperature resistant stainless steel braided pipelines.

11. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The CO2 storage tank is used to store liquid CO2 at a temperature of -20 to -25°C.

12. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The CO2 booster skid draws CO2 from the CO2 storage tank and supplies it to the fracturing truck through a low-pressure pipeline.

13. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The low-pressure pipeline heating device heats the CO2 in the low-pressure pipeline by connecting a dedicated pipeline heater, thereby raising the CO2 temperature, but not exceeding -15 to -10°C.

14. The temperature control system for carbon dioxide fracturing according to claim 8, characterized in that, The fracturing pump truck delivers heated liquid CO2 to the oil and gas wells via high-pressure pipelines.

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