A visual hydrate inhibitor evaluation apparatus and method of use

Abstract

The application discloses a visual hydrate inhibitor evaluation device and a use method, relates to the technical field of hydrate development evaluation, and 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 the kinetic inhibitor storage tank through a pipeline I. The visual reaction kettle is connected with the thermodynamic inhibitor storage tank through a pipeline II. Electromagnetic valves and flow meters are arranged on the pipeline I and the pipeline II. The visual reaction kettle is connected with the gas cylinder through a pipeline III. The visual reaction kettle is connected with the liquid storage tank through a pipeline IV. Stop valves and flow meters are arranged on the pipeline III and the pipeline IV. The visual reaction kettle is connected with a vacuum pump through a pipeline V. A stop valve is arranged on the pipeline V. Temperature sensors and pressure sensors are further arranged on the visual reaction kettle. The generation condition of hydrates under an experimental environment can be observed in real time. In combination with a temperature and pressure change range, inhibitor evaluation can be accurately completed.

Description

Technical Field

[0001] This invention relates to the field of hydrate development and evaluation technology, specifically to a visual hydrate inhibitor evaluation device and its usage method. Background Technology

[0002] Hydrates are simple, crystalline solid compounds formed by water and guest molecules under specific temperature and pressure conditions. Many components in natural gas, such as methane, ethane, propane, carbon dioxide, and hydrogen sulfide, can form hydrates. Hydrates formed during natural gas development, processing, and transportation can cause pipeline blockages, severely impacting the safe and stable operation of gathering and transmission systems. Adding inhibitors is one of the most effective and economical strategies for resolving hydrate blockages. However, this method has limitations: the effectiveness of inhibitors is unclear, and the dosage is difficult to control in practical applications, ultimately leading to waste.

[0003] Hydrate inhibitor evaluation is a crucial research area in fields such as the petroleum industry. These inhibitors are used to prevent water from mixing with oil or natural gas and forming hydrates, which is essential for the safe operation of pipelines and equipment. Below are some common hydrate inhibitor evaluation methods and devices, along with some of their limitations:

[0004] (1) Rheological methods: These methods assess the performance of hydrates by measuring the effects of hydrate inhibitors on hydrates, such as viscosity and flowability. These methods typically use equipment such as rotational viscometers. However, this method is limited by the experimental setup, which cannot withstand high temperatures and pressures, and therefore cannot simulate actual industrial environments. It is not suitable for assessing the effects of hydrate inhibitors on hydrates under high pressure and high temperature conditions.

[0005] (2) Thermodynamic method: The performance of hydrate inhibitors is determined using pressure-temperature phase equilibrium data. 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 setup to experimental conditions, requires precise experimental control, and is not suitable for rapid evaluation in large-scale industrial applications.

[0006] (3) Molecular simulation: The performance of hydrate inhibitors is predicted by calculating the interaction between them and hydrates. This usually requires high-performance computers and molecular dynamics simulation software. This method is limited by the dependence of the simulation model on the initial parameters and the model itself, requires validation of experimental data, and has high computational costs, making it unsuitable for rapid screening of a large number of compounds.

[0007] (4) Flow 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 costly and requires professional maintenance and operation. At the same time, the device cannot be used to observe the hydrate formation in real time through visualization, which greatly reduces the accuracy of the evaluation experiment.

[0008] (5) Field testing method: This method is used to evaluate the performance of hydrate inhibitors in actual industrial settings, including injection tests and in-pipeline tests. This evaluation method is highly dependent on specific industrial environments, making it difficult to generalize. It requires shutdown testing and carries operational risks.

[0009] Therefore, there is an urgent need to design a visual evaluation device for hydrate inhibitors or to further optimize existing methods to facilitate and quickly evaluate inhibitors ready for field use, especially those suitable for evaluating hydrate inhibitors in simulated high-temperature and high-pressure environments. Summary of the Invention

[0010] The purpose of this invention is to provide a visual hydrate inhibitor evaluation device and its usage method, which can observe the formation of hydrates in the experimental environment in real time. Combined with the temperature and pressure change range, it can accurately complete the inhibitor evaluation and efficiently guide the on-site hydrate inhibitor injection work.

[0011] This invention is achieved through the following technical solution:

[0012] A visual hydrate inhibitor evaluation device includes a kinetic inhibitor storage tank, a gas cylinder, a liquid storage tank, a thermodynamic inhibitor storage tank, and at least one visual reaction vessel equipped with a stirrer. The visual reaction vessel is connected to the kinetic inhibitor storage tank via pipeline I; the visual reaction vessel is connected to the thermodynamic inhibitor storage tank via pipeline II, and both pipeline I and pipeline II are equipped with solenoid valves and flow meters. The visual reaction vessel is connected to the gas cylinder via pipeline III; the visual reaction vessel is connected to the liquid storage tank via pipeline IV, and both pipeline III and pipeline IV are equipped with shut-off valves and flow meters. The visual reaction vessel is connected to a vacuum pump via pipeline V, and pipeline V is equipped with a shut-off valve. The visual reaction vessel is also equipped with a temperature sensor and a pressure sensor.

[0013] Furthermore, a pressure reducing valve is installed on pipeline III connected to the gas cylinder. The experimental gas stored in the gas cylinder is pressure-reduced by the pressure reducing valve and then sent into the visualization reactor. An injection pump is installed on pipeline V. The experimental liquid in the liquid storage tank is transported to the visualization reactor through the injection pump on pipeline V.

[0014] Furthermore, injection pumps are installed on pipelines I and II, and the kinetic inhibitor storage tank and the thermodynamic inhibitor storage tank respectively send the corresponding inhibitors to the visualized reaction vessel through the injection pumps on pipelines I and II.

[0015] Furthermore, the visualization reactor is placed inside a low-temperature constant temperature chamber, and each low-temperature constant temperature chamber is equipped with a viewing window.

[0016] Furthermore, the vacuum pump is connected to the body of the visualization reactor via pipeline V, and the pressure inside the visualization reactor is controlled by controlling the opening and closing of the shut-off valve on pipeline V.

[0017] Furthermore, the solenoid valve on pipeline I is connected to the flow meter on pipeline I; the solenoid valve on pipeline II is connected to the flow meter on pipeline II.

[0018] Furthermore, it also includes a flow recorder, which is communicatively connected to the flow meters on pipelines III and IV, respectively.

[0019] A method of using an evaluation device, based on the aforementioned visualized hydrate inhibitor evaluation device, includes the following steps:

[0020] S1. Before the experiment, close the shut-off valves on pipeline III and pipeline V, adjust the temperature inside the visualization reactor to the preset temperature range of the experiment, and zero the flow meter in the evaluation device.

[0021] S2. When the temperature inside the visual reactor reaches the expected temperature requirement, open the shut-off valve on pipeline V, start the vacuum pump, and close the shut-off valve on pipeline V after the pressure inside the reactor reaches the preset pressure value.

[0022] S3: Next, open the shut-off valve on pipeline IV to transfer the experimental liquid from the liquid storage tank to the visual reactor. After confirming that the input volume of the experimental liquid meets the experimental requirements by using the flow meter on pipeline IV, close the shut-off valve on pipeline IV. Then, open the shut-off valve on pipeline III to inject the experimental gas into the visual reactor. After confirming that the amount of experimental gas supplied meets the experimental requirements by using the flow meter on pipeline III, close the shut-off valve on pipeline III.

[0023] S4. Open the solenoid valves on pipeline I and pipeline II to inject the kinetic inhibitor from the kinetic inhibitor tank and the thermodynamic inhibitor from the thermodynamic inhibitor tank into the visualization reactor, respectively. Monitor the corresponding inhibitor input amount through the flow meters on pipeline I and pipeline II. When the reagent input amount meets the experimental requirements, close the solenoid valve on the corresponding pipeline.

[0024] S5. Turn on the stirrer on the visual reaction vessel. Monitor the temperature and pressure changes in the vessel using the temperature and pressure sensors on the visual reaction vessel. During the experiment, observe the formation of hydrates in the vessel. Combine the observation results with the experimental measurement data to evaluate the performance of the inhibitor. After the experiment, turn off the stirrer. After the temperature in the visual reaction vessel is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the vessel.

[0025] Furthermore, the visualization reactor includes two reactors, which are respectively connected to a kinetic inhibitor storage tank, a thermodynamic inhibitor storage tank, a gas cylinder, and a liquid storage tank. One visualization reactor is used as an experimental reactor, and the other visualization reactor is used as a blank control reactor.

[0026] Furthermore, in step S2, the shut-off valve on pipeline V is closed after the pressure inside the vessel reaches -0.1 MPa.

[0027] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0028] This invention proposes a visualized hydrate inhibitor evaluation device, which also includes both thermodynamic and kinetic inhibitor storage tanks. This allows the device to conduct inhibitory performance evaluation experiments when two inhibitors are simultaneously added, providing a theoretical basis for on-site addition work. This addresses the problem of inaccurate evaluation results in current inhibitor evaluation devices that rely solely on changes in temperature and pressure within the reactor to determine hydrate formation. The reaction device in this evaluation system is a visualized reactor, preferably placed in a low-temperature insulated box. The insulated box also has a viewing window, facilitating real-time observation of hydrate formation within the reactor during experiments. Furthermore, it enables the evaluation of the synergistic performance of thermodynamic and kinetic inhibitors, overcoming the shortcomings of current hydrate inhibitor evaluation devices and possessing significant practical value for guiding on-site inhibitor addition work.

[0029] II. In this invention, the method utilizes a visual reactor (preferably a double-layered glass reactor) instead of a high-temperature, high-pressure reactor. This allows researchers to clearly observe the experimental environment inside the reactor through a viewing window (or a transparent material structure) during inhibitor evaluation experiments, thus clearly determining the hydrate formation time and achieving precise recording, thereby improving the accuracy of evaluation results. Most existing methods estimate the hydrate formation time by recording temperature and pressure changes within the device. However, the pressure does not change significantly in the initial stage of hydrate formation, leading to the inaccurate recording of hydrate formation time by traditional devices. Therefore, this method effectively improves the situation where inaccurate evaluation results occur. Attached Figure Description

[0030] Figure 1 This is a schematic diagram of one embodiment of the evaluation device in this invention.

[0031] Figure 2 This is a schematic diagram of another embodiment of the evaluation device in this invention.

[0032] Figure 3 This is a schematic diagram of another embodiment of the evaluation device in this invention.

[0033] Figure 4 This is a diagram showing the formation of a large number of white hydrate crystals in the liquid phase of a reaction vessel.

[0034] Figure 5 This is a temperature-pressure curve plotted during the evaluation experiment of hydrate inhibitors.

[0035] 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. Shut-off valve A; 12. Shut-off valve B; 13. Flow meter C; 14. Flow meter D; 15. Vacuum pump A; 16. Shut-off valve C; 17. Thermostatic chamber A; 18. Visualized reaction vessel A; 19. Pressure sensor A; 20. Temperature sensor A; 21. Pressure sensor B; 22. Temperature sensor B; 23. Thermostatic chamber B; 24. 1. Visualized reaction vessel B; 25. Shut-off valve D; 26. Shut-off 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. Shut-off valve G; 41. Flow meter H; 42. Pipeline I; 43. Pipeline II; 44. Pipeline III; 45. Pipeline IV; 46. Pipeline V; 47. Stirrer. Detailed Implementation

[0036] The present invention will be further described in detail below with reference to embodiments, but the implementation of the present invention is not limited thereto.

[0037] Example 1

[0038] This embodiment is the most basic implementation, a visualized hydrate inhibitor evaluation device, relating to the field of hydrate development and evaluation technology. It includes a kinetic inhibitor storage tank 1, a gas cylinder 9, a liquid storage tank 38, a thermodynamic inhibitor storage tank 37, and a visualized reaction vessel A18 equipped with a stirrer 47. (See reference...) Figure 1The visual reactor A18 is connected to the kinetic inhibitor storage tank 1 via pipeline I42; the visual reactor A18 is connected to the thermodynamic inhibitor storage tank 37 via pipeline II43. Both pipeline I42 and pipeline II43 are equipped with solenoid valves and flow meters. The visual reactor A18 is connected to the gas cylinder 9 via pipeline III44; the visual reactor A18 is connected to the liquid storage tank 38 via pipeline IV45. Both pipeline III44 and pipeline IV45 are equipped with shut-off valves and flow meters. The visual reactor A18 is connected to the vacuum pump A15 via pipeline V46. Pipeline V46 is equipped with a shut-off valve. The visual reactor A18 is also equipped with a temperature sensor A20 and a pressure sensor A19.

[0039] When using this evaluation device to evaluate the performance of hydrate inhibitors, the device usage method includes the following operating steps:

[0040] S1. Before the experiment, close the shut-off valves on pipeline III44 and pipeline V46, adjust the temperature inside the visualization reactor A18 to the preset temperature range of the experiment, and zero the flow meter in the evaluation device.

[0041] S2. When the temperature inside the visual reactor A18 reaches the expected temperature requirement, open the shut-off valve on pipeline V46, start the vacuum pump A15, and close the shut-off valve on pipeline V46 after the pressure inside the reactor reaches the preset pressure value.

[0042] S3: Next, open the shut-off valve on pipeline IV45 to transfer the experimental liquid in liquid storage tank 38 to the visual reactor A18. After confirming that the input volume of experimental liquid meets the experimental requirements by using the flow meter on pipeline IV45, close the shut-off valve on pipeline IV45. Then, open the shut-off valve on pipeline III44 to inject experimental gas into the visual reactor A18. After confirming that the amount of experimental gas supplied meets the experimental requirements by using the flow meter on pipeline III44, close the shut-off valve on pipeline III44.

[0043] S4. Then open the solenoid valves on pipeline I42 and pipeline II43 to inject the kinetic inhibitor in kinetic inhibitor storage tank 1 and the thermodynamic inhibitor in thermodynamic inhibitor storage tank 37 into the visualization reactor A18. Monitor the corresponding inhibitor input amount through the flow meters on pipeline I42 and pipeline II43. When the reagent input amount meets the experimental requirements, close the solenoid valves on the corresponding pipelines.

[0044] S5. Turn on the stirrer 47 on the visual reactor A18. Monitor the temperature and pressure changes in the reactor using the temperature sensor A20 and pressure sensor A19 on the visual reactor A18. During the experiment, the formation of hydrates in the reactor can be observed. Combine the observation results with the experimental measurement data to evaluate the performance of the inhibitor. After the experiment, turn off the stirrer 47. After the temperature in the visual reactor A18 is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor.

[0045] Example 2

[0046] This embodiment is a further optimization of Embodiment 1, providing a visualized hydrate inhibitor evaluation device. It relates to the field of hydrate development and evaluation technology, and includes a kinetic inhibitor storage tank 1, a gas cylinder 9, a liquid storage tank 38, a thermodynamic inhibitor storage tank 37, and a visualized reaction vessel A18 equipped with a stirrer 47. (See reference...) Figure 2 The visual reactor A18 is connected to the kinetic inhibitor storage tank 1 via pipeline I42; the visual reactor A18 is connected to the thermodynamic inhibitor storage tank 37 via pipeline II43. Solenoid valve A2 and flow meter A4 are installed on pipeline I42, and solenoid valve C29 and flow meter E31 are installed on pipeline II43. The visual reactor A18 is connected to the gas cylinder 9 via pipeline III44. A shut-off valve A11 and flow meter C13 are installed on pipeline III44. The visual reactor A18 is connected to the liquid storage tank 38 via pipeline IV45. A shut-off valve G40 and flow meter H41 are installed on pipeline IV45. The visual reactor A18 is connected to the vacuum pump A15 via pipeline V46. A shut-off valve C16 is installed on pipeline V46. The visual reactor A18 is also equipped with a temperature sensor A20 and a pressure sensor A19.

[0047] In this embodiment, a pressure reducing valve 10 is provided on pipeline Ⅲ44 connected to the gas cylinder 9. The experimental gas stored in the gas cylinder 9 is sent into the visualization reactor A18 after the pressure is reduced by the pressure reducing valve 10. An injection pump C28 is provided on pipeline Ⅴ46. The experimental liquid in the liquid storage tank 38 is transported to the visualization reactor A18 through the injection pump C28 on pipeline Ⅴ46.

[0048] Preferably, pipeline I 42 and pipeline II 43 are respectively equipped with injection pump A6 and injection pump D34. The kinetic inhibitor storage tank 1 and thermodynamic inhibitor storage tank 37 respectively send the corresponding inhibitors to the visualization reactor A18 through injection pump A6 and injection pump D34 on pipeline I 42 and pipeline II 43.

[0049] Preferably, the visualization reactor A18 is placed inside a low-temperature constant temperature chamber A17, and the low-temperature constant temperature chamber A17 is provided with a viewing window.

[0050] 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 shut-off valve C16 on pipeline V46.

[0051] Preferably, the solenoid valve A2 and the flow meter A4 on pipeline I 42 are connected by controller A8; the solenoid valve D30 and the flow meter F32 on pipeline II 43 are connected by controller B33.

[0052] Preferably, it also includes a flow recorder 36, which is communicatively connected to flow meters C13 and H41 on pipeline III 44 and pipeline IV 45, respectively.

[0053] When using this evaluation device to evaluate the performance of hydrate inhibitors, the device usage method includes the following operating steps:

[0054] S1. Before the experiment, close the shut-off valves A11 and C16 on pipeline III44 and pipeline V46, adjust the temperature inside the visualization reactor A18 to the preset temperature range of the experiment, and zero the flow meter in the evaluation device.

[0055] S2. When the temperature inside the visual reactor A18 reaches the expected temperature requirement, open the shut-off valve C16 on pipeline V46, start the vacuum pump A15, and close the shut-off valve C16 on pipeline V46 after the pressure inside the reactor reaches the preset pressure value.

[0056] S3: Next, open the shut-off valve G40 on pipeline IV45 to transfer the experimental liquid in liquid storage tank 38 to the visual reactor A18. After confirming that the input volume of experimental liquid meets the experimental requirements by using flow meter H41 on pipeline IV45, close the shut-off valve G40 on pipeline IV45. Then, open the shut-off valve A11 on pipeline III44 to inject experimental gas into the visual reactor A18. After confirming that the amount of experimental gas supplied meets the experimental requirements by using flow meter C13 on pipeline III44, close the shut-off valve A11 on pipeline III44.

[0057] S4. Then open solenoid valves A and B on pipeline I 42 and pipeline II 43 respectively to inject the kinetic inhibitor in kinetic inhibitor storage tank 1 and the thermodynamic inhibitor in thermodynamic inhibitor storage tank 37 into the visualization reactor A18. The flow meter A4 and flow meter E31 on pipeline I 42 and pipeline II 43 respectively monitor the corresponding inhibitor input. When the reagent input meets the experimental requirements, close the solenoid valves on the corresponding pipelines.

[0058] S5. Turn on the stirrer 47 on the visual reactor A18. Monitor the temperature and pressure changes in the reactor using the temperature sensor A20 and pressure sensor A19 on the visual reactor A18. During the experiment, the formation of hydrates in the reactor can be observed. Combine the observation results with the experimental measurement data to evaluate the performance of the inhibitor. After the experiment, turn off the stirrer 47. After the temperature in the visual reactor A18 is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor.

[0059] Example 3

[0060] Compared with Example 2, this embodiment includes two visualization reactors. The two visualization reactors 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 visualization reactor is used as an experimental reactor and the other visualization reactor is used as a blank control reactor.

[0061] More specifically, the visualized hydrate inhibitor evaluation device in this embodiment includes a kinetic inhibitor storage tank 1, solenoid valve A2, solenoid valve B3, flow meter A4, flow meter B5, injection pump A6, injection pump B7, controller A8, gas cylinder 9, pressure reducing valve 10, shut-off valve A11, shut-off valve B12, flow meter C13, flow meter D14, vacuum pump A15, shut-off valve C16, constant temperature chamber A17, visualized reaction vessel A18, pressure sensor A19, temperature sensor A20, and pressure... Force sensor B21, temperature sensor B22, constant temperature chamber B23, visual reaction vessel B24, shut-off valve D25, shut-off 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, shut-off valve G40, flow meter H41, connection method reference Figure 3 As shown.

[0062] In this embodiment, the visual reactor A18 is placed in the constant temperature chamber A17, and the visual reactor B24 is placed in the constant temperature chamber B23. Both the visual reactor A18 and the visual reactor B24 are equipped with magnetic stirrers 47. Both the constant temperature chamber A17 and the constant temperature chamber B23 are low-temperature constant temperature chambers with viewing windows.

[0063] When using the evaluation device in this embodiment to evaluate the performance of hydrate inhibitors, the method of using the device includes the following steps:

[0064] S1. Before the experiment, set the shut-off valves A11, B12, C16, D25, and E26 of the evaluation device to the closed state, and set the temperatures of the constant temperature chambers A17 and B23 to the preset experimental temperatures. Then, perform zeroing operations on the flow meters A4, B5, C13, D14, E31, F32, G39, and H41.

[0065] S2. After the temperature inside the visual reactors A18 and B24 reaches the experimental requirements, open the shut-off valves C16 and D25, and vacuum pumps A15 and B27. After the pressure inside the reactors reaches -0.1MPa, close the shut-off valves C16 and D25.

[0066] S3: Open shut-off valve E26 and start injection pump C28 to inject liquid into the reactor. Observe the flow meter G39 on the injection pipeline to ensure that the amount of liquid injected into the reactor meets the experimental requirements. Then close shut-off valve E26 and injection pump C28. Open shut-off valves A11 and B12, adjust the pressure appropriately through pressure reducing valve 10, and inject experimental gas into the reactor through gas cylinder 9. Observe the flow meters C13 and D14 on the injection pipeline to ensure that the amount of gas injected into the reactor meets the experimental requirements. Then close shut-off valves A11 and B12.

[0067] S4: After opening solenoid valves A2, B3, C29, and D30 via controllers A8 and B33, start injection pumps A6, B7, D34, and E35 to inject the kinetic and thermodynamic inhibitors into the two visualization reactors, respectively. Especially when a blank experiment is required, one of the visualization reactors can be designated as the blank reactor, and the solenoid valve connected to it should be closed to prevent inhibitor injection. After ensuring the injected inhibitor level meets experimental requirements by observing the flow meter on the injection line, close the corresponding solenoid valves and injection pumps.

[0068] S5: Turn on the magnetic stirrer 37 in the visualization reactor to stir. The temperature and pressure changes in the reactor are monitored in real time by pressure sensor A19, temperature sensor A20, pressure sensor B21, and temperature sensor B22. During the experiment, the formation of hydrates in the reactor is observed through the viewing window on the constant temperature chamber. 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 constant temperature chamber to an appropriate temperature, let it stand for 5 hours, and then release the gas and liquid in the visualization reactor.

[0069] In this invention, when evaluating the performance of the hydrate inhibitor using the evaluation device in this embodiment, the evaluation experiments involved refer to:

[0070] The experiment consisted 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 and control experiments, the inhibitory performance under the experimental conditions was evaluated.

[0071] The blank experiment procedure is as follows: First, under conditions where the temperature is higher than the equilibrium temperature, the pressure inside the visualization reactor is increased to the working pressure. Then, the temperature inside the visualization reactor is adjusted (e.g., by adjusting the temperature through a constant-temperature water bath), and the temperature and pressure changes are recorded. When hydrates form, the pressure in the system decreases significantly. At this point, the temperature is gradually increased until the hydrates completely decompose. Finally, the temperature-pressure curve of the hydrate is plotted. The temperature and pressure represented by the intersection of the temperature-pressure curves during the heating and cooling processes are the equilibrium conditions for hydrate formation.

[0072] The experimental procedure is as follows: First, evacuate the reactor using a vacuum pump, and inject the test liquid into the sealed, visualized reactor using an injection pump; fill the buffer container with methane gas; pressurize the methane gas in the buffer container using a pump (such as a constant pressure pump) until the set value is reached, then turn off the pump and inject high-pressure methane gas into the visualized reactor; set the rotation speed and control the temperature of the constant temperature water bath to cool it down; turn on the data acquisition system to record the pressure and temperature values ​​of the reactor; after the experiment, safely release the pressure in the visualized reactor and pipelines, clean the instruments, and organize and analyze the experimental data.

[0073] In the experiment, the formation of hydrates can be determined in two ways:

[0074] (1) Directly observe through the visualization window whether a large number of white hydrate crystals are formed in the liquid phase, such as Figure 4 As shown.

[0075] (2) Based on the temperature and pressure change curves over time, it is difficult to determine the initial formation time of hydrates because the pressure inside the visualized reactor keeps decreasing due to cooling and gas dissolution; only when a large amount of hydrates are formed inside the reactor, resulting in a significant increase in temperature and decrease in pressure, can the time point of large-scale hydrate formation be determined. Figure 5 The time point / time period corresponding to the box in the middle, such as Figure 5 As shown.

[0076] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Any simple modifications or equivalent changes made to the above embodiments based on the technical essence of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method of using a visual hydrate inhibitor evaluation device, characterized in that: The evaluation device includes 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 equipped with a stirrer (47). The visual reactor is connected to the kinetic inhibitor storage tank (1) via pipeline I (42); the visual reactor is connected to the thermodynamic inhibitor storage tank (37) via pipeline II (43). Both pipeline I (42) and pipeline II (43) are equipped with solenoid valves and flow meters. The visual reactor is connected to the gas cylinder (9) via pipeline III (44); the visual reactor is connected to the liquid storage tank (38) via pipeline IV (45). Both pipeline III (44) and pipeline IV (45) are equipped with shut-off valves and flow meters. The visual reactor is connected to a vacuum pump via pipeline V (46). Pipeline V (46) is equipped with a shut-off valve. The visual reactor is also equipped with a temperature sensor and a pressure sensor. The usage method includes the following steps: S1. Before the experiment, close the shut-off valves on pipeline III (44) and pipeline V (46), adjust the temperature inside the visualization reactor to the preset temperature range of the experiment, and zero the flow meter in the evaluation device. S2. When the temperature inside the visual reactor reaches the expected temperature requirement, open the shut-off valve on pipeline V (46), start the vacuum pump, and close the shut-off valve on pipeline V (46) after the pressure inside the reactor reaches the preset pressure value. S3. Next, open the shut-off valve on pipeline IV (45) to transfer the experimental liquid in the liquid storage tank (38) to the visual reactor. After confirming that the amount of experimental liquid input meets the experimental requirements by using the flow meter on pipeline IV (45), close the shut-off valve on pipeline IV (45). Then, open the shut-off valve on pipeline III (44) to inject the experimental gas into the visual reactor. After confirming that the amount of experimental gas supplied meets the experimental requirements by using the flow meter on pipeline III (44), close the shut-off valve on pipeline III (44). S4. Open the solenoid valves on pipeline I (42) and pipeline II (43) to 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. Monitor the corresponding inhibitor input amount through the flow meters on pipeline I (42) and pipeline II (43). When the reagent input amount meets the experimental requirements, close the solenoid valves on the corresponding pipelines. S5. Turn on the stirrer (47) on the visual reactor. Monitor the temperature and pressure changes in the reactor using the temperature and pressure sensors on the visual reactor. During the experiment, observe the formation of hydrates in the reactor. Combine the observation results with the experimental measurement data to evaluate the performance of the inhibitor. After the experiment, turn off the stirrer (47). After the temperature in the visual reactor is adjusted to a certain temperature condition, let it stand, and then release the experimental gas and experimental liquid in the reactor.

2. The method of use according to claim 1, characterized in that: A pressure reducing valve (10) is provided on pipeline III (44) connected to the gas cylinder (9). The experimental gas stored in the gas cylinder (9) is sent into the visualization reactor after the pressure is reduced by the pressure reducing valve (10). An injection pump is provided on pipeline V (46). The experimental liquid in the liquid storage tank (38) is transported to the visualization reactor through the injection pump on pipeline V (46).

3. The method of use according to claim 1, characterized in that: Injection pumps are installed on pipeline I (42) and pipeline II (43). Kinetic inhibitor storage tank (1) and thermodynamic inhibitor storage tank (37) respectively send the corresponding inhibitors to the visualization reactor through the injection pumps on pipeline I (42) and pipeline II (43).

4. The method of use according to claim 1, characterized in that: The visualization reactor is placed inside a low-temperature constant temperature chamber, and each chamber is equipped with a viewing window.

5. The method of use according to claim 1, characterized in that: The vacuum pump is connected to the body of the visualization reactor via pipeline V (46), and the pressure inside the visualization reactor is controlled by controlling the opening and closing of the shut-off valve on pipeline V (46).

6. The method of use 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. The method of use 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), respectively.

8. The method of use according to claim 1, characterized in that: The visualization reactor includes two 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 visualization reactors is used as an experimental reactor, and the other visualization reactor is used as a blank control reactor.

9. The method of use according to claim 1, characterized in that: In step S2, after the pressure inside the vessel reaches -0.1 MPa, the shut-off valve on pipeline V (46) is closed.

10. The method of use according to claim 1, characterized in that: In step S5, the formation of hydrates is determined using the following two methods during the experiment: a. Directly observe through the visualization window whether a large number of white hydrate crystals are formed in the liquid phase; b. Determine the formation of hydrates based on the curves showing the changes in temperature and pressure over time.

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