Visual hydrate inhibitor evaluation device and use method

Abstract

The invention discloses a visual hydrate inhibitor evaluation device and a use method, and relates to the technical field of hydrate development and evaluation.The visual hydrate inhibitor evaluation device comprises a kinetic inhibitor storage tank, a gas cylinder, a liquid storage tank, a thermodynamic inhibitor storage tank and at least one visual reaction kettle provided with a stirrer; the visual reaction kettle is connected with a kinetic inhibitor storage tank through a pipeline I; the visual reaction kettle is connected with a thermodynamic inhibitor storage tank through a pipeline II, the pipeline I and the pipeline II are respectively provided with an electromagnetic valve and a flowmeter, and the visual reaction kettle is connected with a gas cylinder through a pipeline III; the visual reaction kettle is connected with a liquid storage tank through a pipeline IV, the pipeline III and the pipeline IV are each provided with a stop valve and a flow meter, the visual reaction kettle is connected with a vacuum pump through a pipeline V, the pipeline V is provided with a stop valve, and the visual reaction kettle is further provided with a temperature sensor and a pressure sensor. The generation condition of hydrate in an experimental environment can be observed in real time, and inhibitor evaluation can be accurately completed by combining the temperature and pressure change range.

Description

Technical Field

[0001] The present invention relates to the technical field of hydrate development evaluation, and in particular to a visual hydrate inhibitor evaluation device and a use method thereof. Background Art

[0002] Hydrate refers to a simple crystalline solid compound formed by water and guest molecules under specific temperature and pressure conditions. Many components in natural gas, such as methane, ethane, propane, carbon dioxide, hydrogen sulfide, etc., can form hydrates. Hydrates generated during the development, processing and transportation of natural gas may cause pipeline blockage, seriously affecting the safe and stable operation of the gathering and transportation system. Adding inhibitors is one of the most effective and economical strategies to solve the hydrate blockage problem. However, this method has certain limitations: for example, the inhibitor effect is unclear, and the amount of inhibitor injection is difficult to grasp in actual application, which ultimately results in waste.

[0003] Hydrate inhibitor evaluation is a very important research direction in the oil industry and other fields. They are used to prevent water from mixing with oil or natural gas and forming hydrates, which is crucial for the safe operation of pipelines and equipment. The following are some common hydrate inhibitor evaluation methods and devices, as well as some of their shortcomings: (1) Rheological method: The performance of hydrate inhibitors is evaluated by measuring the effects of hydrate inhibitors on hydrates, such as viscosity and fluidity. These methods are usually tested using equipment such as a rotational viscometer. This method is limited by the experimental device, which cannot withstand high temperature and pressure and cannot simulate the actual industrial environment. It is not suitable for evaluating the effects of hydrate inhibitors on hydrates under high pressure and high temperature conditions.

[0004] (2) Thermodynamic method: Use pressure-temperature phase equilibrium data to determine the performance of hydrate inhibitors. This includes the use of devices such as high-pressure small-volume cells or Raman spectrometers. This method is limited by the sensitivity of the experimental equipment to experimental conditions and requires accurate experimental control. It is not suitable for rapid evaluation of large-scale industrial applications.

[0005] (3) Molecular simulation: The performance of hydrate inhibitors is predicted by computationally simulating the interaction between hydrate inhibitors and hydrates. This usually requires high-performance computers and molecular dynamics simulation software. This method is limited by the simulation model's dependence on initial parameters and models, requires experimental data verification, and has a high computational cost, making it unsuitable for rapid screening of a large number of compounds.

[0006] (4) Mobile laboratory method: Design a device specifically for simulating the performance of hydrate inhibitors under high pressure and high temperature conditions, including a high pressure circulation device and a high temperature and high pressure device. The experimental device is expensive and requires professional maintenance and operation. At the same time, the device cannot observe the hydrate formation in real time through visual means, which greatly reduces the accuracy of the evaluation experiment.

[0007] (5) Field test method: used to evaluate the performance of hydrate inhibitors in actual industrial sites, including injection tests, in-pipeline tests, etc. This evaluation method is highly dependent on the specific industrial environment, is difficult to generalize, requires shutdown testing, and has operational risks.

[0008] Therefore, there is an urgent need to design a visual hydrate inhibitor evaluation device or to further optimize the existing methods so as to conveniently and quickly evaluate the inhibitors to be put into use on site, especially the evaluation of hydrate inhibitors that can be applied to simulate high temperature and high pressure environments. Summary of the invention

[0009] The purpose of the present invention is to provide a visual hydrate inhibitor evaluation device and a method for use, which can observe the formation of hydrates in an experimental environment in real time, and can accurately complete the inhibitor evaluation in combination with the temperature and pressure variation range, and efficiently guide the on-site hydrate inhibitor injection work.

[0010] The present invention is achieved through the following technical solutions: A visualized hydrate inhibitor evaluation device comprises a kinetic inhibitor storage tank, a gas cylinder, a liquid storage tank, a thermodynamic inhibitor storage tank and at least one visualized reactor provided with a stirrer, wherein the visualized reactor is connected to the kinetic inhibitor storage tank via pipeline I; the visualized reactor is connected to the thermodynamic inhibitor storage tank via pipeline II, both pipelines I and II are provided with solenoid valves and flow meters, the visualized reactor is connected to the gas cylinder via pipeline III; the visualized reactor is connected to the liquid storage tank via pipeline IV, both pipelines III and IV are provided with stop valves and flow meters, the visualized reactor is connected to a vacuum pump via pipeline V, pipeline V is provided with a stop valve, and the visualized reactor is also provided with a temperature sensor and a pressure sensor.

[0011] Furthermore, a pressure reducing valve is provided on pipeline III connected to the gas cylinder, and the experimental gas stored in the gas cylinder is sent to the visualization reactor after the pressure is reduced by the pressure reducing valve; an injection pump is provided on pipeline V, and the experimental liquid in the liquid storage tank is transported to the visualization reactor through the injection pump on pipeline V.

[0012] Furthermore, injection pumps are provided on pipelines I and II, and the kinetic inhibitor storage tank and the thermodynamic inhibitor storage tank deliver corresponding inhibitors to the visualization reactor through the injection pumps on pipelines I and II, respectively.

[0013] Furthermore, the visualization reactor is placed in a low-temperature thermostat, and the low-temperature thermostat is provided with a visual window.

[0014] Furthermore, the vacuum pump is connected to the visualized reactor body through pipeline V, and the pressure in the visualized reactor body is controlled by controlling the opening and closing of the stop valve on pipeline V.

[0015] Furthermore, the solenoid valve on pipeline I is controlled and connected to the flowmeter on pipeline I; the solenoid valve on pipeline II is controlled and connected to the flowmeter on pipeline II.

[0016] Furthermore, it also includes a flow recorder, which is communicatively connected with the flow meters on pipeline III and pipeline IV respectively.

[0017] A method for using an evaluation device, based on the aforementioned visual hydrate inhibitor evaluation device, comprises the following steps: S1. Before the experiment, close the stop valves on pipeline III and pipeline V, adjust the temperature inside the visual reactor to within the preset temperature range, and reset the flowmeter in the evaluation device to zero; S2. When the temperature in the visualized reactor reaches the expected temperature requirement, open the stop valve on pipeline V, start the vacuum pump, and close the stop valve on pipeline V after the pressure in the reactor reaches the preset pressure value; S3: Open the stop valve on pipeline IV again, transfer the experimental liquid in the liquid storage tank to the visualization reactor, and after confirming that the amount of the experimental liquid input meets the experimental requirements through the flow meter on pipeline IV, close the stop valve on pipeline IV; then open the stop valve on pipeline III, inject the experimental gas into the visualization reactor, and after confirming that the amount of the experimental gas input meets the experimental requirements through the flow meter on pipeline III, close the stop valve on pipeline III; S4, then open the solenoid valves on pipelines I and II, and inject the kinetic inhibitor in the kinetic inhibitor tank and the thermodynamic inhibitor in the thermodynamic inhibitor tank into the visualization reactor respectively, and monitor the corresponding inhibitor input amounts through the flow meters provided on pipelines I and II respectively. When the reagent input amounts meet the experimental requirements, close the solenoid valves on the corresponding pipelines; S5. Turn on the agitator on the visualization reactor, and monitor the changes in temperature and pressure in the reactor through the temperature sensor and pressure sensor installed on the visualization reactor. During the experiment, the hydrate formation in the reactor can be observed, and the performance of the inhibitor can be evaluated by combining the observation results with the experimental measurement data. After the experiment, turn off the agitator, wait until the temperature in the visualization reactor is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor.

[0018] Furthermore, the visualization reactor includes two visualization reactors, which are respectively connected to the kinetic inhibitor storage tank, the thermodynamic inhibitor storage tank, the gas cylinder and the liquid storage tank, one of which is used as an experimental reactor and the other is used as a blank control reactor.

[0019] Furthermore, in step S2, the stop valve on pipeline V is closed after the pressure in the kettle reaches -0.1 MPa.

[0020] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. In the present invention, a visual hydrate inhibitor evaluation device is proposed, and a thermodynamic inhibitor storage tank and a kinetic inhibitor storage tank are also set up at the same time, so that the device can perform an inhibition performance evaluation experiment when two inhibitors are added together, providing a theoretical basis for on-site filling work, so as to solve the problem that the current inhibitor evaluation experimental device only judges the hydrate formation by the temperature and pressure changes in the kettle, resulting in inaccurate evaluation results. The reaction device in the evaluation device is a visual reactor, and the visual reactor is preferably placed in a low-temperature insulation box, and a visual window is also provided in the insulation box, which is convenient for real-time observation of the hydrate formation in the kettle during the experiment, and can evaluate the synergistic performance of thermodynamic inhibitors and kinetic inhibitors, which improves the shortcomings of the current hydrate inhibitor evaluation device and has great practical significance for guiding on-site inhibitor filling work.

[0021] 2. In the present invention, this method uses a visual reactor (preferably a double-layer glass reactor) to replace a high-temperature and high-pressure reactor, so that during the inhibitor evaluation experiment, the experimenter can clearly observe the experimental environment in the reactor through a visual window (or a transparent material structure) and clearly understand the hydrate formation time, thereby achieving accurate recording and improving the accuracy of the evaluation results. Most existing methods infer the hydrate formation time by recording the temperature and pressure change data in the device, but the pressure will not change significantly in the early stage of hydrate formation, resulting in the inability of traditional devices to accurately record the hydrate formation time. Therefore, the inaccuracy of the evaluation results can be effectively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic structural diagram of one embodiment of the evaluation device in the present invention.

[0023] Figure 2 It is a structural schematic diagram of another implementation manner of the evaluation device in the present invention.

[0024] Figure 3 It is a structural schematic diagram of another implementation manner of the evaluation device in the present invention.

[0025] Figure 4 It is a graphic representation of the formation of a large amount of white hydrate crystals in the liquid phase in the reactor.

[0026] Figure 5 This is a temperature-pressure curve plotted in the hydrate inhibitor evaluation experiment.

[0027] Among them, 1. Kinetic inhibitor storage tank; 2. Solenoid valve A; 3. Solenoid valve B; 4. Flow meter A; 5. Flow meter B; 6. Injection pump A; 7. Injection pump B; 8. Controller A; 9. Gas cylinder; 10. Pressure reducing valve; 11. Stop valve A; 12. Stop valve B; 13. Flow meter C; 14. Flow meter D; 15. Vacuum pump A; 16. Stop valve C; 17. Constant temperature box A; 18. Visual reactor A; 19. Pressure sensor A; 20. Temperature sensor A; 21. Pressure sensor B; 22. Temperature sensor B; 23. Constant temperature box B; 24 , visual reactor B; 25. stop valve D; 26. stop valve E; 27. vacuum pump B; 28. injection pump C; 29. ​​solenoid valve C; 30. solenoid valve D; 31. flow meter E; 32. flow meter F; 33. controller B; 34. injection pump D; 35. injection pump E; 36. flow recorder; 37. thermodynamic inhibitor storage tank; 38. liquid storage tank; 39. flow meter G; 40. stop valve G; 41. flow meter H; 42. pipeline I; 43. pipeline II; 44. pipeline III; 45. pipeline IV; 46. pipeline V; 47. agitator. DETAILED DESCRIPTION

[0028] The present invention is further described in detail below in conjunction with examples, but the embodiments of the present invention are not limited thereto.

[0029] Example 1 This embodiment is the most basic implementation method, a visual hydrate inhibitor evaluation device, which relates to the technical field of hydrate development evaluation, includes a kinetic inhibitor storage tank 1, a gas cylinder 9, a liquid storage tank 38, a thermodynamic inhibitor storage tank 37 and a visual reactor A18 with a stirrer 47, reference Figure 1 The visualized reactor A18 is connected to the kinetic inhibitor storage tank 1 through pipeline Ⅰ42; the visualized reactor A18 is connected to the thermodynamic inhibitor storage tank 37 through pipeline Ⅱ43, and both pipeline Ⅰ42 and pipeline Ⅱ43 are provided with solenoid valves and flow meters. The visualized reactor A18 is connected to the gas cylinder 9 through pipeline Ⅲ44; the visualized reactor A18 is connected to the liquid storage tank 38 through pipeline Ⅳ45, and both pipeline Ⅲ44 and pipeline Ⅳ45 are provided with stop valves and flow meters. The visualized reactor is connected to the vacuum pump A15 through pipeline Ⅴ46, and pipeline Ⅴ46 is provided with a stop valve. The visualized reactor A18 is also provided with a temperature sensor A20 and a pressure sensor A19.

[0030] When using this evaluation device to evaluate the performance of hydrate inhibitors, the method of using the device includes the following operating steps: S1. Before the experiment, close the stop valves on pipeline III44 and pipeline V46, adjust the temperature inside the visualization reactor A18 to within the preset temperature range, and return the flowmeter in the evaluation device to zero; S2. When the temperature in the visualized reactor A18 reaches the expected temperature requirement, open the stop valve on the pipeline V46, start the vacuum pump A15, and close the stop valve on the pipeline V46 after the pressure in the reactor reaches the preset pressure value; S3: Open the stop valve on pipeline IV45 again, transfer the experimental liquid in the liquid storage tank 38 to the visualization reactor A18, and after confirming that the amount of the input experimental liquid meets the experimental requirements through the flow meter on pipeline IV45, close the stop valve on pipeline IV45; then open the stop valve on pipeline III44, inject the experimental gas into the visualization reactor A18, and after confirming that the amount of the experimental gas input meets the experimental requirements through the flow meter on pipeline III44, close the stop valve on pipeline III44; S4, open the solenoid valves on pipeline I 42 and pipeline II 43 again, inject the kinetic inhibitor in the kinetic inhibitor storage tank 1 and the thermodynamic inhibitor in the thermodynamic inhibitor storage tank 37 into the visualization reactor A18 respectively, monitor the corresponding inhibitor input amount through the flowmeters provided on pipeline I 42 and pipeline II 43 respectively, and close the solenoid valves on the corresponding pipelines when the reagent input amount meets the experimental requirements; S5. Turn on the agitator 47 on the visualization reactor A18, and monitor the changes in temperature and pressure in the reactor through the temperature sensor A20 and the pressure sensor A19 provided on the visualization reactor A18. During the experiment, the hydrate formation in the reactor can be observed, and the performance of the inhibitor can be evaluated by combining the observation results with the experimental measurement data. After the experiment, turn off the agitator 47, wait until the temperature in the visualization reactor A18 is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor body.

[0031] Example 2 This embodiment is a further optimization of the embodiment 1, a visual hydrate inhibitor evaluation device, which relates to the technical field of hydrate development evaluation, comprises a kinetic inhibitor storage tank 1, a gas cylinder 9, a liquid storage tank 38, a thermodynamic inhibitor storage tank 37 and a visual reactor A18 provided with a stirrer 47, and the like. Figure 2The visualized reactor A18 is connected to the kinetic inhibitor storage tank 1 through pipeline Ⅰ42; the visualized reactor A18 is connected to the thermodynamic inhibitor storage tank 37 through pipeline Ⅱ43, and the pipeline Ⅰ42 is provided with a solenoid valve A2 and a flowmeter A4, and the pipeline Ⅱ43 is provided with a solenoid valve C29 and a flowmeter E31. The visualized reactor A18 is connected to the gas cylinder 9 through pipeline Ⅲ44; the pipeline Ⅲ44 is provided with a stop valve A11 and a flowmeter C13, the visualized reactor A18 is connected to the liquid storage tank 38 through pipeline Ⅳ45, and the pipeline Ⅳ45 is provided with a stop valve G40 and a flowmeter H41, the visualized reactor A18 is connected to the vacuum pump A15 through pipeline Ⅴ46, and the pipeline Ⅴ46 is provided with a stop valve C16. The visualized reactor A18 is also provided with a temperature sensor A20 and a pressure sensor A19.

[0032] In this embodiment, a pressure reducing valve 10 is provided on the pipeline III44 connected to the gas cylinder 9, and the experimental gas stored in the gas cylinder 9 is sent to the visualization reactor A18 after the pressure is reduced by the pressure reducing valve 10; an injection pump C28 is provided on the pipeline V46, and the experimental liquid in the liquid storage tank 38 is transported to the visualization reactor A18 through the injection pump C28 on the pipeline V46.

[0033] Preferably, an injection pump A6 and an injection pump D34 are respectively provided on pipeline I 42 and pipeline II 43, and the kinetic inhibitor storage tank 1 and the thermodynamic inhibitor storage tank 37 deliver the corresponding inhibitors to the visualization reactor A18 through the injection pumps A6 and injection pumps D34 on pipeline I 42 and pipeline II 43 respectively.

[0034] Preferably, the visualization reaction kettle A18 is placed in a low-temperature constant temperature box A17, and a visual window is provided on the low-temperature constant temperature box A17.

[0035] Preferably, the vacuum pump is connected to the body of the visualization reactor A18 via pipeline V46, and the pressure inside the visualization reactor A18 is controlled by controlling the opening and closing of the stop valve C16 on the pipeline V46.

[0036] Preferably, the solenoid valve A2 on pipeline Ⅰ42 and the flowmeter A4 on pipeline Ⅰ42 are controlled and connected via controller A8; the solenoid valve D30 on pipeline Ⅱ43 and the flowmeter F32 on pipeline Ⅱ43 are controlled and connected via controller B33.

[0037] Preferably, a flow recorder 36 is also included, and the flow recorder 36 is communicatively connected with the flow meter C13 and the flow meter H41 on the pipeline III 44 and the pipeline IV 45 respectively.

[0038] When using this evaluation device to evaluate the performance of hydrate inhibitors, the method of using the device includes the following operating steps: S1. Before the experiment, close the stop valve A11 and stop valve C16 on pipeline III44 and pipeline V46, adjust the temperature inside the visualization reactor A18 to within the preset temperature range, and return the flowmeter in the evaluation device to zero; S2. When the temperature in the visualized reactor A18 reaches the expected temperature requirement, open the stop valve C16 on the pipeline V46, start the vacuum pump A15, and close the stop valve C16 on the pipeline V46 after the pressure in the reactor reaches the preset pressure value; S3: Open the stop valve G40 on pipeline IV45, transfer the experimental liquid in the liquid storage tank 38 to the visualization reactor A18, and after confirming that the amount of the input experimental liquid meets the experimental requirements through the flow meter H41 on pipeline IV45, close the stop valve G40 on pipeline IV45; open the stop valve A11 on pipeline III44, inject the experimental gas into the visualization reactor A18, and after confirming that the amount of the experimental gas input meets the experimental requirements through the flow meter C13 on pipeline III44, close the stop valve A11 on pipeline III44; S4, then open the solenoid valve A and the solenoid valve B on the pipeline I 42 and the pipeline II 43, and inject the kinetic inhibitor in the kinetic inhibitor tank 1 and the thermodynamic inhibitor in the thermodynamic inhibitor tank 37 into the visual reactor A18 respectively, and monitor the corresponding inhibitor input amount through the flowmeter A4 and the flowmeter E31 provided on the pipeline I 42 and the pipeline II 43 respectively. When the reagent input amount meets the experimental requirements, close the solenoid valve on the corresponding pipeline; S5. Turn on the agitator 47 on the visualization reactor A18, and monitor the changes in temperature and pressure in the reactor through the temperature sensor A20 and the pressure sensor A19 provided on the visualization reactor A18. During the experiment, the hydrate formation in the reactor can be observed, and the performance of the inhibitor can be evaluated by combining the observation results with the experimental measurement data. After the experiment, turn off the agitator 47, wait until the temperature in the visualization reactor A18 is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor body.

[0039] Example 3 Compared with Example 2, this embodiment is different in that it includes two visualized reactors, which are respectively connected to the kinetic inhibitor storage tank 1, the thermodynamic inhibitor storage tank 37, the gas cylinder 9 and the liquid storage tank 38, one of which is used as an experimental reactor and the other is used as a blank control reactor.

[0040] More specifically, the visual hydrate inhibitor evaluation device in this embodiment includes a kinetic inhibitor storage tank 1, a solenoid valve A2, a solenoid valve B3, a flow meter A4, a flow meter B5, an injection pump A6, an injection pump B7, a controller A8, a gas cylinder 9, a pressure reducing valve 10, a stop valve A11, a stop valve B12, a flow meter C13, a flow meter D14, a vacuum pump A15, a stop valve C16, a thermostat A17, a visual reactor A18, a pressure sensor A19, a temperature sensor A20, a pressure Force sensor B21, temperature sensor B22, constant temperature box B23, visual reactor B24, stop valve D25, stop valve E26, vacuum pump B27, injection pump C28, solenoid valve C29, solenoid valve D30, flow meter E31, flow meter F32, controller B33, injection pump D34, injection pump E35, flow recorder 36, thermodynamic inhibitor storage tank 37, liquid storage tank 38 (38), flow meter G39, stop valve G40, flow meter H41, the connection method refers to Figure 3 shown.

[0041] In this embodiment, the visualization reactor A18 is placed in the thermostat A17, and the visualization reactor B24 is placed in the thermostat B23. The visualization reactor A18 and the visualization reactor B24 are both provided with a magnetic stirrer 47. The thermostat A17 and the thermostat B23 are both low-temperature thermostats with visual windows.

[0042] When the evaluation device in this embodiment is used to evaluate the performance of the hydrate inhibitor, the method for using the device includes the following operating steps: S1. Before the experiment, first adjust the stop valve A11, stop valve B12, stop valve C16, stop valve D25, and stop valve E26 of the evaluation device to the closed state, and set the temperature of the thermostat A17 and the thermostat B23 to the preset temperature of the experiment, and return the flowmeter A4, flowmeter B5, flowmeter C13, flowmeter D14, flowmeter E31, flowmeter F32, flowmeter G39 and flowmeter H41 to zero.

[0043] S2. After the temperature in the visualized reactor A18 and the visualized reactor B24 reaches the experimental requirements, open the stop valve C16 and the stop valve D25, and vacuum pump A15 and vacuum pump B27. After the pressure in the reactor reaches -0.1MPa, close the stop valve C16 and the stop valve D25.

[0044] S3: Open the stop valve E26 and start the injection pump C28 to inject the liquid into the kettle. After ensuring that the amount of liquid injected into the kettle reaches the experimental requirements by observing the flow meter G39 on the injection pipeline, close the stop valve E26 and the injection pump C28. Open the stop valve A11 and the stop valve B12, adjust the pressure appropriately through the pressure reducing valve 10, inject the experimental gas into the kettle through the gas cylinder 9, and after ensuring that the amount of gas injected into the kettle reaches the experimental requirements by observing the flow meter C13 and the flow meter D14 on the injection pipeline, close the stop valve A11 and the stop valve B12.

[0045] S4: After opening the solenoid valve A2, the solenoid valve B3, the solenoid valve C29 and the solenoid valve D30 through the controller A8 and the controller B33, the injection pump A6, the injection pump B7, the injection pump D34 and the injection pump E35 are started to inject the kinetic inhibitor and the thermodynamic inhibitor into the two visual reactors respectively. In particular, when a blank experiment is required, one of the visual reactors can be determined as a blank experiment reactor, and the solenoid valve connected to the blank experiment reactor is set to be closed, and the inhibitor is not added. By observing the flow meter on the injection pipeline, it is ensured that the injection of the inhibitor into the reactor meets the experimental requirements, and then the solenoid valve and injection pump on the corresponding pipeline are closed.

[0046] S5: Turn on the magnetic stirrer 37 in the visualization reactor for stirring. The temperature and pressure changes in the reactor are monitored in real time through pressure sensor A19, temperature sensor A20, pressure sensor B21, and temperature sensor B22. During the experiment, the hydrate formation in the reactor is observed through the visual window on the thermostat, and the performance of the inhibitor is evaluated by combining the observation results with the experimental measurement data. After the experiment, turn off the magnetic stirrer 37 in the visualization reactor, adjust the temperature of the thermostat to an appropriate temperature, and then let it stand for 5 hours, and then release the gas and liquid in the visualization reactor.

[0047] In the present invention, when the evaluation device in this embodiment is used to evaluate the performance of the hydrate inhibitor, the evaluation experiment involved refers to: It consists of a blank experiment in a pure water-methane system and a control experiment in an inhibitor-methane system. By comparing and analyzing the hydrate formation time in the blank experiment and the control experiment, the inhibitor performance under the experimental environment is evaluated.

[0048] The blank experiment process is as follows: First, under the condition that the temperature is higher than the equilibrium temperature, the pressure in the visualization reactor is raised to the working pressure, and then the visualization reactor is adjusted (such as adjusting the temperature in the visualization reactor by a constant temperature water bath), and the temperature and pressure changes are recorded. When hydrates are generated, the pressure in the system decreases significantly. At this time, the temperature begins to rise until the hydrates are completely decomposed, and finally the temperature-pressure curve of the hydrate is drawn. During the heating and cooling process, the temperature and pressure represented by the intersection of the temperature-pressure curve are the equilibrium conditions for hydrate formation.

[0049] The control experiment process is as follows: first, use a vacuum pump to evacuate the reactor, and inject the test liquid into the closed visual reactor through the injection pump; fill the buffer container with methane gas; use a pump (such as a constant pressure pump) to pressurize the methane gas in the buffer container until it reaches the set value, and then turn off the pump and inject high-pressure methane gas into the visual reactor; set the speed and control the constant temperature water bath to cool down; turn on the data acquisition system to record the pressure and temperature of the reactor; after the experiment, safely vent the pressure in the visual reactor and pipelines, clean the instrument; organize and analyze the experimental data.

[0050] There are two ways to determine hydrate formation in the experiment: (1) Observe directly through the visualization window whether there is a large amount of white hydrate crystals in the liquid phase, such as Figure 4 shown.

[0051] (2) According to the curve of temperature and pressure changing with time, the pressure in the visualized reactor keeps decreasing due to the temperature drop and gas dissolution, making it difficult to determine the time of initial hydrate formation. When a large amount of hydrate is formed in the reactor, resulting in a significant increase in temperature and a decrease in pressure, the time of large-scale hydrate formation can be determined. Figure 5 The time point / time period corresponding to the box in the figure), such as Figure 5 shown.

[0052] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A visual hydrate inhibitor evaluation device, characterized in that: The invention comprises a kinetic inhibitor storage tank (1), a gas cylinder (9), a liquid storage tank (38), a thermodynamic inhibitor storage tank (37) and at least one visual reactor provided with a stirrer (47). The visual reactor is connected to the kinetic inhibitor storage tank (1) via a pipeline I (42); the visual reactor is connected to the thermodynamic inhibitor storage tank (37) via a pipeline II (43), and both pipelines I (42) and II (43) are provided with electromagnetic valves and flow meters. The visual reactor is connected to the gas cylinder (9) via a pipeline III (44); the visual reactor is connected to the liquid storage tank (38) via a pipeline IV (45), and both pipelines III (44) and IV (45) are provided with stop valves and flow meters. The visual reactor is connected to a vacuum pump via a pipeline V (46), and pipeline V (46) is provided with a stop valve. The visual reactor is also provided with a temperature sensor and a pressure sensor.

2. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: A pressure reducing valve (10) is provided on the pipeline III (44) connected to the gas cylinder (9), and the experimental gas stored in the gas cylinder (9) is sent to the visualization reactor after the pressure is reduced by the pressure reducing valve (10); an injection pump is provided on the pipeline V (46), and the experimental liquid in the liquid storage tank (38) is sent to the visualization reactor through the injection pump on the pipeline V (46).

3. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: Injection pumps are provided on pipeline I (42) and pipeline II (43), and the kinetic inhibitor storage tank (1) and the thermodynamic inhibitor storage tank (37) deliver the corresponding inhibitors to the visualization reactor through the injection pumps on pipeline I (42) and pipeline II (43), respectively.

4. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: The visualization reaction kettle is placed in a low-temperature constant temperature box, and the low-temperature constant temperature box is provided with a visual window.

5. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: The vacuum pump is connected to the visualization reactor body through pipeline V (46), and the pressure in the visualization reactor is controlled by opening and closing the stop valve on pipeline V (46).

6. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: The solenoid valve on pipeline I (42) is connected to the flow meter on pipeline I (42) for control; the solenoid valve on pipeline II (43) is connected to the flow meter on pipeline II (43) for control.

7. A visual hydrate inhibitor evaluation device according to claim 1, characterized in that: It also includes a flow recorder (36), which is communicatively connected to the flow meters on pipeline III (44) and pipeline IV (45).

8. A method for using an evaluation device, characterized in that: The visual hydrate inhibitor evaluation device according to claim 1 comprises the following steps: S1. Before the experiment, close the stop valves on pipeline III (44) and pipeline V (46), adjust the temperature inside the visual reactor to within the preset temperature range of the experiment, and reset the flow meter in the evaluation device to zero; S2. When the temperature in the visualized reactor reaches the expected temperature requirement, open the stop valve on pipeline V (46), start the vacuum pump, and close the stop valve on pipeline V (46) after the pressure in the reactor reaches the preset pressure value; S3: Open the stop valve on pipeline IV (45) again, transfer the experimental liquid in the liquid storage tank (38) to the visualization reactor, and after confirming that the amount of the experimental liquid input meets the experimental requirements through the flow meter on pipeline IV (45), close the stop valve on pipeline IV (45); open the stop valve on pipeline III (44), inject the experimental gas into the visualization reactor, and after confirming that the amount of the experimental gas input meets the experimental requirements through the flow meter on pipeline III (44), close the stop valve on pipeline III (44); S4, then open the solenoid valves on pipeline I (42) and pipeline II (43), and inject the kinetic inhibitor in the kinetic inhibitor storage tank (1) and the thermodynamic inhibitor in the thermodynamic inhibitor storage tank (37) into the visual reactor respectively, and monitor the corresponding inhibitor input amount through the flow meters provided on pipeline I (42) and pipeline II (43), and when the reagent input amount meets the experimental requirements, close the solenoid valves on the corresponding pipelines; S5. Turn on the agitator (47) on the visualization reactor, and monitor the changes in temperature and pressure in the reactor through the temperature sensor and pressure sensor provided on the visualization reactor. During the experiment, the hydrate formation in the reactor can be observed, and the performance of the inhibitor can be evaluated by combining the observation results with the experimental measurement data. After the experiment is over, turn off the agitator (47), wait for the temperature in the visualization reactor to be adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor.

9. The method for using the evaluation device according to claim 8, characterized in that: The visualized reactors include two visualized reactors, which are respectively connected to a kinetic inhibitor storage tank (1), a thermodynamic inhibitor storage tank (37), a gas cylinder (9) and a liquid storage tank (38). One of the visualized reactors is used as an experimental reactor, and the other visualized reactor is used as a blank control reactor.

10. The method for using the evaluation device according to claim 8, characterized in that: In step S2, after the pressure in the kettle reaches -0.1 MPa, the stop valve on pipeline V (46) is closed.

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