Application of ethylenediamine compounds as synergistic agents for hydrate kinetic inhibitors

Abstract

The present invention provides the use of ethylenediamine compounds as hydrate kinetic inhibitor synergistic agents and a hydrate kinetic inhibitor composition and its preparation method and application. The present invention uses ethylenediamine compounds as synergistic agents and hydrate kinetic inhibitors to obtain a composite system, which is used in oil and gas development or transportation processes, and can significantly inhibit the formation of hydrates, thereby solving the pipeline blockage problem caused by the formation of hydrates in oil and gas development and transportation processes.

Description

Technical Field

[0001] The invention relates to the application of an ethylenediamine reagent as a hydrate kinetic inhibitor synergistic reagent, belonging to the technical field of oil and gas exploitation and transportation. Background Art

[0002] Pipeline blockage caused by hydrate formation is one of the key issues in deepwater oil and gas drilling, hydrate development, and long-distance natural gas transportation. Since these pipelines face a low temperature and high pressure operating environment, hydrates are easily generated in the pipelines, causing pipeline blockage, seriously affecting the progress of operations and the safety of personnel and equipment. Therefore, how to prevent the formation of hydrates has received widespread attention in the oil and gas industry.

[0003] At present, the main methods for preventing hydrate formation include dehydration, heat preservation and heating, pressure reduction, and adding chemical inhibitors. The dehydration method is only applicable to natural gas transportation pipelines, the heat preservation and heating method is costly and inefficient, and the pressure reduction method is only applicable to adjusting pipeline pressure in emergency situations. These methods have great limitations. Adding chemical inhibitors can avoid the limitations of the above methods and effectively prevent the problem of blockage caused by hydrate formation. Some hydrate kinetic inhibitors have been used in some oil and gas fields, but in order to increase the application range of hydrate kinetic inhibitors, they are usually used in combination with a variety of synergistic agents (such as methanol, ethylene glycol, etc.). These synergistic agents will produce synergistic effects with hydrate kinetic inhibitors, enhance the inhibitory effect of hydrate kinetic inhibitors on hydrates, and reduce the dosage of hydrate kinetic inhibitors. Therefore, the development of synergistic agents compatible with hydrate kinetic inhibitors can not only enhance the inhibitory effect of hydrate kinetic inhibitors, but also greatly reduce the economic cost, which is crucial to the development of hydrate kinetic inhibitors. Summary of the invention

[0004] In order to solve the above problems, the purpose of the present invention is to provide the use of ethylenediamine compounds as synergistic agents for hydrate kinetic inhibitors and a hydrate kinetic inhibitor composition. The composite system obtained by compounding ethylenediamine compounds as synergistic agents with hydrate kinetic inhibitors is used in oil and gas development or transportation processes, which can significantly inhibit the formation of hydrates, thereby solving the problem of pipeline blockage caused by the formation of hydrates in the process of oil and gas development and transportation.

[0005] In order to achieve the above object, the present invention provides the use of ethylenediamine compounds as hydrate kinetic inhibitor synergistic agents, wherein the ethylenediamine compounds have a structure shown in Formula I:

[0006]

[0007] In Formula I, R 1 , R 2 , R3 The same or different, each independently selected from H, C 1 -C 2 Preferably, the ethylenediamine compound is selected from one or a combination of two or more of N-ethylethylenediamine, N,N-dimethylethylenediamine and N,N'-dimethylethylenediamine.

[0008] According to a specific embodiment of the present invention, preferably, in the above application, the hydrate kinetic inhibitor includes one or a combination of two or more of PVP, Inhibex 501, and hydrate kinetic inhibitor A; wherein the hydrate kinetic inhibitor A is obtained by binary copolymerization of N-vinyl caprolactam and vinyl n-butyl ether.

[0009] The present invention also provides a hydrate kinetics inhibition composition, which comprises a hydrate kinetics inhibitor and an ethylenediamine compound; wherein the ethylenediamine compound has a structure shown in Formula I:

[0010]

[0011] In Formula I, R 1 , R 2 , R 3 The same or different, each independently selected from H, C 1 -C 2 of alkyl.

[0012] According to a specific embodiment of the present invention, preferably, the ethylenediamine compound is selected from one or a combination of two or more of N-ethylethylenediamine, N,N-dimethylethylenediamine, and N,N'-dimethylethylenediamine.

[0013] According to a specific embodiment of the present invention, preferably, the hydrate kinetic inhibitor comprises one or a combination of two or more of PVP (polyvinyl pyrrolidone), Inhibex 501, and hydrate kinetic inhibitor A (polyvinyl caprolactam vinyl n-butyl ether copolymer); wherein the hydrate kinetic inhibitor A is obtained by binary copolymerization of N-vinyl caprolactam and vinyl n-butyl ether.

[0014] According to a specific embodiment of the present invention, preferably, the relative molecular mass of the hydrate kinetic inhibitor A is 1000-50000.

[0015] According to a specific embodiment of the present invention, preferably, the hydrate kinetics inhibitor is hydrate kinetics inhibitor A.

[0016] The structure of the hydrate kinetic inhibitor A of the present invention is illustrated by Formula II:

[0017]

[0018] Wherein, the molar ratio of the N-vinyl caprolactam structural unit to the vinyl n-butyl ether structural unit is x:y=9:1-1:1.

[0019] According to a specific embodiment of the present invention, preferably, the preparation method of the hydrate kinetic inhibitor A comprises the following steps: mixing N-vinyl caprolactam and vinyl n-butyl ether with a solvent, adding an initiator, performing a binary copolymerization reaction, and then adding a terminator to obtain the hydrate kinetic inhibitor.

[0020] According to a specific embodiment of the present invention, preferably, in the method for preparing the hydrate kinetic inhibitor A, the binary copolymerization reaction temperature is 323.15-363.15K, and the reaction time is 5-12h.

[0021] According to a specific embodiment of the present invention, preferably, in the method for preparing the hydrate kinetic inhibitor A, the molar ratio of N-vinyl caprolactam to vinyl n-butyl ether is 9:1-1:1.

[0022] According to a specific embodiment of the present invention, preferably, in the preparation method of the hydrate kinetic inhibitor A, the amount of the initiator is 0.01%-0.5%, calculated based on the total weight of the N-vinyl caprolactam and vinyl n-butyl ether as 100%.

[0023] According to a specific embodiment of the present invention, preferably, in the preparation method of the hydrate kinetic inhibitor A, the initiator includes one or a combination of two or more of azobisisobutyronitrile, dimethyl azobisisobutyrate, azobisisoheptanenitrile and tert-butyl hydroperoxide.

[0024] According to a specific embodiment of the present invention, preferably, in the preparation method of the hydrate kinetic inhibitor A, the amount of the terminator is 0.01%-0.1%, calculated based on the total weight of the N-vinyl caprolactam and vinyl n-butyl ether as 100%.

[0025] According to a specific embodiment of the present invention, preferably, in the method for preparing the hydrate kinetic inhibitor A, the terminator includes one of styrene and methacrylic acid or a combination of the two.

[0026] According to a specific embodiment of the present invention, preferably, in the method for preparing the hydrate kinetic inhibitor A, the weight ratio of the solvent to the sum of the N-vinyl caprolactam and the vinyl n-butyl ether is 2-10:1.

[0027] According to a specific embodiment of the present invention, preferably, in the method for preparing the hydrate kinetic inhibitor A, the solvent includes one or a combination of two or more of ethanol, isopropanol, N,N-dimethylformamide, and n-propanol.

[0028] According to a specific embodiment of the present invention, the preparation method of the above-mentioned hydrate kinetic inhibitor A comprises the following specific steps:

[0029] (1) adding N-vinyl caprolactam and vinyl n-butyl ether monomers into a solvent and mixing them uniformly to obtain a mixture;

[0030] (2) adding an initiator to the mixture, raising the temperature to the target reaction temperature, and reacting under the protection of a protective gas (e.g., a nitrogen atmosphere), and finally adding a terminator to terminate the reaction. After the reaction is completed, the resulting solution is vacuum dried at a drying temperature of 313.15-343.15 K to obtain the hydrate kinetic inhibitor A.

[0031] The present invention also provides the use of the hydrate kinetics inhibition composition for inhibiting hydrate formation during oil and gas development or transportation.

[0032] According to a specific embodiment of the present invention, preferably, the hydrate kinetics inhibition composition is applied to an oil-gas-water three-phase system or a gas-water two-phase system.

[0033] According to a specific embodiment of the present invention, preferably, the pressure of the oil-gas-water three-phase system or the gas-water two-phase system is 0.5-25 MPa, and the temperature is -10°C to 30°C.

[0034] According to a specific embodiment of the present invention, preferably, based on the total weight of water in the system as 100%, the amount of the hydrate kinetic inhibitor is 0.5-5.0wt%; the amount of the ethylenediamine compound is 0.1-5.0wt%, more preferably 0.5-2.0wt%, and further preferably 1.0wt%.

[0035] The present invention has the following beneficial technical effects:

[0036] (1) The present invention uses ethylenediamine compounds as hydrate kinetic inhibitor synergistic agents and compounding with hydrate kinetic inhibitors to significantly enhance the inhibitory effect of hydrate kinetic inhibitors on hydrates, reduce the dosage of hydrate kinetic inhibitors, delay the formation of hydrates, and solve the hazards caused by the formation of hydrates;

[0037] (2) The hydrate kinetic inhibitor synergistic agent provided by the present invention can be directly compounded with the hydrate kinetic inhibitor for use without the need for secondary processing; and the synergistic agent has the advantages of small dosage, low cost and significant effect;

[0038] (3) The hydrate kinetic inhibitor synergistic reagent provided by the present invention can be dissolved in alcohols and water at the same time, and is easy to be applied to gas-water systems or oil-gas-water systems. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] Figure 1 This is the infrared spectrum of hydrate kinetic inhibitor A. DETAILED DESCRIPTION

[0040] In order to have a clearer understanding of the technical features, purposes and beneficial effects of the present invention, the technical solution of the present invention is now described in detail below, but it should not be construed as limiting the applicable scope of the present invention.

[0041] In order to investigate the inhibitory performance of ethylenediamine reagents as synergistic reagents in combination with different hydrate kinetic inhibitors on the hydrate formation process, the inhibitory performance of different hydrate kinetic inhibitors, ethylenediamine reagents, and the combined systems of ethylenediamine reagents and different hydrate kinetic inhibitors on the hydrate formation process were evaluated respectively below. Unless otherwise specified, the devices and reagent materials used in the present invention can be obtained through commercial channels.

[0042] Specifically, the device used in the evaluation experiment mainly consists of six parts: a visible high-pressure sapphire kettle, a temperature sensor, a pressure sensor, a data acquisition system, a constant temperature air bath, and a magnetic stirring device; the volume of the visible high-pressure sapphire kettle is 59cm 3 , with an inner diameter of 2.54cm, and can withstand a maximum pressure of 40MPa to ensure the safety of the evaluation experiment operation; the errors of the pressure sensor and temperature sensor are ±0.01MPa and ±0.1K respectively; the temperature error of the constant temperature air bath is also ±0.1K, and the adjustment of the experimental temperature is mainly controlled by the constant temperature air bath.

[0043] The method for evaluating the inhibition performance of different hydrate kinetic inhibitors, ethylenediamine reagents, and the mixed systems of ethylenediamine reagents and different hydrate kinetic inhibitors on the hydrate formation process is as follows:

[0044] First, clean the visible high-pressure sapphire kettle by soaking it with petroleum ether and ethanol once, then clean it three times with anhydrous ethanol, then open the inlet and outlet valves of the visible high-pressure sapphire kettle, and purge it with nitrogen to make the inside completely dry;

[0045] Add the prepared test solutions (hydrate kinetic inhibitor, ethylenediamine reagent, and ethylenediamine reagent and different hydrate kinetic inhibitor compound systems) into a visible high-pressure sapphire kettle, and use a vacuum pump to evacuate the kettle, and close the valve after the air in the kettle is pumped out to prevent the presence of air from interfering with the experimental results;

[0046] Open the air inlet valve of the balance kettle, add sufficient experimental gas into the balance kettle, and then close the air inlet valve of the balance kettle;

[0047] Turn on the constant temperature air bath and set the temperature of the constant temperature air bath to the experimental target temperature. When the temperature in the visible high-pressure sapphire kettle is stable at the target temperature, open the air inlet valve of the visible high-pressure sapphire kettle, and pass the experimental gas from the balance kettle into the visible high-pressure sapphire kettle. After reaching the target pressure, close the air inlet valve, turn on the magnetic stirring device, and keep the stirring speed unchanged during the entire experiment;

[0048] Turn on the cold light source, observe the appearance and morphological changes of hydrates through the visual window of the constant temperature air bath, and record them with a camera. At the same time, the temperature and pressure data in the kettle are saved in real time through the data acquisition system.

[0049] The test gas used in the evaluation experiment was methane with a purity of 99.99%.

[0050] The hydrate kinetic inhibitor PVP (manufactured by Sigma-Aldrich) used in the evaluation experiment was purchased from the Aladdin reagent platform, and Inhibex 501 was purchased from Ashland Group. The hydrate kinetic inhibitor A used was prepared by the following preparation method:

[0051] (1) selecting N-vinyl caprolactam and vinyl n-butyl ether as synthetic raw materials, using isopropyl alcohol as a solvent for polymerization, and uniformly mixing the synthetic raw materials and the solvent to obtain a mixture; wherein the amounts of N-vinyl caprolactam and vinyl n-butyl ether are 5.8155 g and 4.1845 g, respectively; and the amount of isopropyl alcohol is 30 g;

[0052] (2) Add the above mixture into a three-necked round-bottom flask, wait until the temperature of the thermostatic water bath reaches 353.15K, add 0.01% of the total weight of the two monomers as the initiator azobisisobutyronitrile into the three-necked round-bottom flask, then quickly fix the three-necked round-bottom flask in the thermostatic water bath, install a condenser on the three-necked round-bottom flask, introduce nitrogen into the three-necked round-bottom flask, and start stirring. Keep the water bath temperature and stirring speed constant during the reaction. Stop heating after 10 hours of reaction, and add 0.05% of the total weight of the two monomers as the terminator styrene into the three-necked round-bottom flask;

[0053] (3) When the system temperature is cooled to room temperature, the nitrogen gas is stopped and the stirring is turned off, and the product in the three-necked round-bottom flask is transferred to a beaker to obtain a crude product of hydrate kinetic inhibitor A;

[0054] (4) transferring the liquid in the beaker to a rotary evaporator, purifying the crude product of the hydrate kinetic inhibitor A by the rotary evaporator, taking out the purified product, and vacuum drying it at a temperature of 323.15 K to obtain the hydrate kinetic inhibitor A, whose relative molecular mass is 11499, and finally sealing it and storing it in a dry and cool place for future use;

[0055] The obtained hydrate kinetic inhibitor A was subjected to infrared spectroscopy analysis, and the obtained infrared spectrum is shown in FIG. Figure 1 As shown, from Figure 1 It can be seen that the binary copolymer, i.e., the hydrate kinetic inhibitor A, has a peak at 912 cm -1 、993cm -1 、3080cm -1 、1682cm -1 There are no C=CH、=CH、C=C absorption peaks on the left and right, which indicates that the unsaturated hydrocarbons disappear; 1617cm -1 The strong absorption peaks on the left and right are the C=O absorption peaks on the polymer molecule caprolactam, 1430 cm -1 The absorption peaks on the left and right are strong absorption peaks of CN on the polymer molecule caprolactam; 2876cm -1 With 2853cm -1 The two strong absorption peaks on the left and right are the absorption peaks of saturated CH symmetric stretching vibration and antisymmetric stretching vibration respectively; at 1225-1200cm -1 There is no obvious absorption peak around 1150cm -1 The strong absorption peaks on the left and right are the absorption peaks of fatty ether COC, which indicates that vinyl ether has been polymerized with N-vinyl caprolactam to convert it into fatty ether; In summary, Figure 1 The solid infrared data results shown indicate that N-vinyl caprolactam has been successfully polymerized with vinyl n-butyl ether monomer and has a high purity, contains no or only a trace amount of unreacted monomers, and the synthesized product is the target product.

[0056] The evaluation experiment uses the nucleation time of hydrates, that is, the length of TVO, to judge the strength of the inhibition performance of different hydrate kinetic inhibitors, ethylenediamine reagents, and the complex systems of ethylenediamine reagents and different hydrate kinetic inhibitors on the hydrate formation process (nucleation process). The length of TPD-TVO is used to judge the inhibition performance of different hydrate kinetic inhibitors, ethylenediamine reagents, and the complex systems of ethylenediamine reagents and different hydrate kinetic inhibitors on the hydrate growth process.

[0057] Among them, the nucleation time of hydrate, i.e. TVO, is determined by real-time monitoring of the camera and the pressure sensor on the pressure change of the system. When the camera first captures the appearance of hydrate nuclei in the visible high-pressure sapphire reactor and the pressure sensor monitors that the pressure of the system begins to drop, the time at this time is the nucleation time of hydrate in the system.

[0058] TPD is the time when a significant pressure drop occurs in the system. The time when hydrate formation (i.e., nucleation) is observed is always earlier than the time when a significant pressure drop occurs in the system. Therefore, the length of TPD-TVO can be used to judge the inhibitory performance of different hydrate kinetic inhibitors, ethylenediamine reagents, and ethylenediamine reagents and different hydrate kinetic inhibitor complex systems on the hydrate growth process.

[0059] Comparative Example 1

[0060] 10 g of deionized water was added to a visible high-pressure sapphire kettle, and 6.19 MPa of experimental gas was introduced at a temperature of 274.76 K to conduct an evaluation experiment. It was found that the TVO of the hydrate in the system was less than 1 minute, indicating that in this evaluation system, hydrates (methane hydrates) were formed rapidly because no hydrate kinetic inhibitors and synergistic reagents were used.

[0061] Comparative Example 2

[0062] 10 g of an aqueous solution containing the existing conventional hydrate kinetic inhibitor PVP (the concentration of PVP in the aqueous solution is 0.5 wt % based on the total weight of water) was added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa was introduced at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO time of the hydrate in the system was 5 min, and the TPD-TVO time was 6 min, indicating that in this evaluation system, due to the use of the hydrate kinetic inhibitor PVP, the formation of hydrates was also inhibited to a certain extent compared with Comparative Example 1.

[0063] Comparative Example 3

[0064] 10 g of an aqueous solution containing the existing conventional hydrate kinetic inhibitor Inhibex 501 (the concentration of Inhibex 501 in the aqueous solution was 0.5 wt% based on the total weight of water) was added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa was introduced at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO time of the hydrate in the system was 10 min, and the TPD-TVO time was 25 min, indicating that in this evaluation system, due to the use of the hydrate kinetic inhibitor Inhibex 501, the formation of hydrates was also inhibited to a certain extent compared with Comparative Example 1.

[0065] Comparative Example 4

[0066] 10 g of aqueous solutions containing different ethylenediamine reagents (based on the total weight of water, the concentration of the ethylenediamine reagent in the aqueous solution is 1.0 wt% or 0.5 wt%) are added to a visible high-pressure sapphire kettle, and an experimental gas of corresponding pressure is introduced into the visible high-pressure sapphire kettle under certain temperature conditions to carry out an evaluation experiment; wherein, the specific substance of the ethylenediamine reagent, the temperature and pressure data of the evaluation experiment process, and the TVO obtained by the evaluation experiment are shown in Tables 1 and 2 below.

[0067] Table 1 Inhibition effect of different ethylenediamine reagents on hydrates at a concentration of 1.0wt%

[0068]

[0069] Table 2 Inhibition effect of different ethylenediamine reagents on hydrates at a concentration of 0.5wt%

[0070]

[0071] It can be seen from Tables 1 and 2 that the TVO time of the ethylenediamine reagent solution under the current experimental conditions is less than 1 min, indicating that the hydrate formation process is almost not inhibited and a large amount of hydrates are quickly formed in the system; it further shows that when the ethylenediamine reagent is used alone, no matter its concentration is high or low, it cannot have a significant inhibitory effect on the formation of hydrates.

[0072] Comparative Example 5

[0073] 10 g of an aqueous solution containing hydrate kinetic inhibitor A (based on the total weight of water, the concentration of the hydrate kinetic inhibitor in the aqueous solution is 0.5 wt%) is added to a visible high-pressure sapphire kettle, and 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO of the hydrate in the system was 94 min, and the TPD-TVO time was 232 min, indicating that in this evaluation system, due to the presence of hydrate kinetic inhibitor A, the formation of hydrates was significantly inhibited.

[0074] Example 1

[0075] 10 g of an aqueous solution containing hydrate kinetic inhibitor PVP and N-ethylethylenediamine (based on the total weight of water, the concentration of PVP in the aqueous solution is 0.5 wt %, and the concentration of N-ethylethylenediamine is 1.0 wt %) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K for an evaluation experiment. It was found that the TVO of the hydrate in the system was 10 min, and the TPD-TVO time was 15 min. This indicates that compared with the evaluation system of Comparative Example 2 in which the hydrate kinetic inhibitor PVP is used alone, since the evaluation system of this embodiment further adds N-ethylethylenediamine as a synergistic reagent, the hydrate formation time is further prolonged, and the formation of hydrates (methane hydrates) is further inhibited.

[0076] Example 2

[0077] 10 g of an aqueous solution containing a hydrate kinetic inhibitor PVP and N,N-dimethylethylenediamine (based on the total weight of water, the concentration of PVP in the aqueous solution is 0.5 wt %, and the concentration of N,N-dimethylethylenediamine is 1.0 wt %) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K for an evaluation experiment. It was found that the TVO of the hydrate in the system was 15 min, and the TPD-TVO time was 27 min, indicating that compared with the evaluation system of Comparative Example 2 using the hydrate kinetic inhibitor PVP alone, since N,N-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged, and the formation of hydrates (methane hydrates) is further inhibited.

[0078] Example 3

[0079] 10 g of an aqueous solution containing a hydrate kinetic inhibitor PVP and N,N'-dimethylethylenediamine (based on the total weight of water, the concentration of PVP in the aqueous solution is 0.5 wt%, and the concentration of N,N'-dimethylethylenediamine is 1.0 wt%) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K for an evaluation experiment. It was found that the TVO of the hydrate in the system was 22 min, and the TPD-TVO time was 32 min, indicating that compared with the evaluation system of Comparative Example 2 using the hydrate kinetic inhibitor PVP alone, since N,N'-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged, and the formation of hydrates (methane hydrates) is further inhibited.

[0080] Example 4

[0081] 10 g of an aqueous solution containing the hydrate kinetic inhibitor Inhibex 501 and N-ethylethylenediamine (based on the total weight of water, the concentration of Inhibex 501 in the aqueous solution is 0.5 wt %, and the concentration of N-ethylethylenediamine is 1.0 wt %) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO time of the hydrate in the system was 15 min, and the TPD-TVO time was 18 min, indicating that compared with the evaluation system of Comparative Example 3 using the hydrate kinetic inhibitor Inhibex 501 alone, since the evaluation system of this embodiment further adds the N-ethylethylenediamine synergistic reagent, the hydrate formation time is further prolonged, and the formation of hydrates (methane hydrates) is further inhibited.

[0082] Example 5

[0083] 10 g of an aqueous solution containing the hydrate kinetic inhibitor Inhibex 501 and N,N-dimethylethylenediamine (based on the total weight of water, the concentration of Inhibex 501 in the aqueous solution is 0.5 wt %, and the concentration of N,N-dimethylethylenediamine is 1.0 wt %) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO of the hydrate in the system was 17 min, and the TPD-TVO time was 30 min, indicating that compared with the evaluation system of Comparative Example 3 using the hydrate kinetic inhibitor Inhibex 501 alone, since the evaluation system of this embodiment further adds N,N-dimethylethylenediamine as a synergistic reagent, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0084] Example 6

[0085] 10 g of an aqueous solution containing the hydrate kinetic inhibitor Inhibex 501 and N,N'-dimethylethylenediamine (based on the total weight of water, the concentration of Inhibex 501 in the aqueous solution is 0.5 wt%, and the concentration of N,N'-dimethylethylenediamine is 1.0 wt%) is added to a visible high-pressure sapphire kettle, and an experimental gas of 6.19 MPa is introduced into the visible high-pressure sapphire kettle at a temperature of 274.76 K to carry out an evaluation experiment. It was found that the TVO of the hydrate in the system was 28 min, and the TPD-TVO time was 35 min, indicating that compared with the evaluation system of Comparative Example 3 using the hydrate kinetic inhibitor Inhibex 501 alone, since the evaluation system of this embodiment further adds N,N'-dimethylethylenediamine as a synergistic reagent, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0086] Example 7

[0087] 10 g of hydrate kinetic inhibitor A and an aqueous solution of N-ethylethylenediamine (based on the total weight of water, the concentration of hydrate kinetic inhibitor A in the aqueous solution is 0.5 wt%, and the concentration of N-ethylethylenediamine is 1.0 wt%) are added to a visible high-pressure sapphire kettle. At a temperature of 274.76 K, 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle for an evaluation experiment. It is found that the TVO of the hydrate in the system is 148 min, and the TPD-TVO time is 152 min. This indicates that compared with the evaluation system of Comparative Example 5 in which the hydrate kinetic inhibitor A is used alone, since the evaluation system of this embodiment further adds the N-ethylethylenediamine synergistic reagent, the hydrate formation time is further prolonged, and the formation of hydrates (methane hydrates) is further inhibited.

[0088] Example 8

[0089] 10 g of hydrate kinetic inhibitor A and N,N-dimethylethylenediamine aqueous solution (based on the total weight of water, the concentration of hydrate kinetic inhibitor A in the aqueous solution is 0.5 wt%, and the concentration of N,N-dimethylethylenediamine is 1.0 wt%) are added to a visible high-pressure sapphire kettle. At a temperature of 274.76 K, 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle for evaluation experiments. It is found that the TVO of the hydrate in the system is 162 min, and the TPD-TVO time is 174 min. This shows that compared with the evaluation system of Comparative Example 5 in which the hydrate kinetic inhibitor A is used alone, since N,N-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0090] Example 9

[0091] 10 g of hydrate kinetic inhibitor A and N,N'-dimethylethylenediamine aqueous solution (based on the total weight of water, the concentration of hydrate kinetic inhibitor A in the aqueous solution is 0.5 wt%, and the concentration of N,N'-dimethylethylenediamine is 1.0 wt%) are added to a visible high-pressure sapphire kettle. At a temperature of 274.76 K, 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle for evaluation experiments. It is found that the TVO of the hydrate in the system is 258 min, and the TPD-TVO time is 303 min. This shows that compared with the evaluation system of Comparative Example 5 in which the hydrate kinetic inhibitor A is used alone, since N,N'-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0092] Example 10

[0093] 10 g of hydrate kinetic inhibitor A and N,N'-dimethylethylenediamine aqueous solution (based on the total weight of water, the concentration of hydrate kinetic inhibitor A in the aqueous solution is 0.5 wt%, and the concentration of N,N'-dimethylethylenediamine is 2.0 wt%) are added to a visible high-pressure sapphire kettle. At a temperature of 274.76 K, 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle for evaluation experiments. It is found that the TVO of the hydrate in the system is 208 min, and the TPD-TVO time is 273 min. This shows that compared with the evaluation system of Comparative Example 5 in which the hydrate kinetic inhibitor A is used alone, since N,N'-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0094] Comparing the evaluation system of Example 9 with the evaluation system of this example, it can be seen that the evaluation system of this example uses a higher concentration of N,N'-dimethylethylenediamine aqueous solution as a synergistic reagent, but the hydrate formation time is shortened and the degree of hydrate inhibition is not as good as that of Example 9.

[0095] Embodiment 11

[0096] 10 g of hydrate kinetic inhibitor A and N,N'-dimethylethylenediamine aqueous solution (based on the total weight of water, the concentration of hydrate kinetic inhibitor A in the aqueous solution is 0.5 wt%, and the concentration of N,N'-dimethylethylenediamine is 5.0 wt%) are added to a visible high-pressure sapphire kettle. At a temperature of 274.76 K, 6.19 MPa of experimental gas is introduced into the visible high-pressure sapphire kettle for evaluation experiments. It is found that the TVO of the hydrate in the system is 228 min, and the TPD-TVO time is 285 min. This shows that compared with the evaluation system of Comparative Example 5 using the hydrate kinetic inhibitor A alone, since N,N'-dimethylethylenediamine synergistic reagent is further added to the evaluation system of this embodiment, the hydrate formation time is further prolonged and the formation of hydrates (methane hydrates) is further inhibited.

[0097] Comparing the evaluation system of Example 9 with the evaluation system of this example, it can be seen that the evaluation system of this example uses a higher concentration of N,N'-dimethylethylenediamine aqueous solution as a synergistic reagent, but the hydrate formation time is shortened and the degree of hydrate inhibition is not as good as that of Example 9.

[0098] The above is only a specific embodiment of the present invention, and cannot be used to limit the scope of the invention. Therefore, the replacement of equivalent components, or equivalent changes and modifications made according to the protection scope of the patent of the present invention, should still fall within the scope of this patent. In addition, the technical features of the present invention can be freely combined with each other, with each other and with each other, and with each other.

Claims

1. Application of ethylenediamine compounds as hydrate kinetic inhibitor synergistic agents, wherein the ethylenediamine compounds have a structure shown in Formula I: In Formula I, R 1 , R 2 , R 3 The same or different, each independently selected from H, C1-C2 alkyl; The hydrate kinetic inhibitor includes one or a combination of two or more of PVP, Inhibex 501, and hydrate kinetic inhibitor A; The preparation method of the hydrate kinetic inhibitor A comprises the following steps: N-vinyl caprolactam and vinyl n-butyl ether are mixed with a solvent, an initiator is added, a binary copolymerization reaction is carried out, and then a terminator is added to obtain the hydrate kinetic inhibitor; The binary copolymerization reaction temperature is 323.15-363.15K, and the reaction time is 5-12h; The molar ratio of N-vinyl caprolactam to vinyl n-butyl ether is 9:1-1:

1.

2. The use according to claim 1, wherein: The ethylenediamine compound is selected from one or a combination of two or more of N-ethylethylenediamine, N,N-dimethylethylenediamine and N,N'-dimethylethylenediamine.

3. A hydrate kinetics inhibition composition, comprising a hydrate kinetics inhibitor and an ethylenediamine compound; in, The ethylenediamine compound has a structure shown in Formula I: In Formula I, R 1 , R 2 , R 3 The same or different, each independently selected from H, C1-C2 alkyl; The hydrate kinetic inhibitor includes one or a combination of two or more of PVP, Inhibex 501, and hydrate kinetic inhibitor A; The preparation method of the hydrate kinetic inhibitor A comprises the following steps: N-vinyl caprolactam and vinyl n-butyl ether are mixed with a solvent, an initiator is added, a binary copolymerization reaction is carried out, and then a terminator is added to obtain the hydrate kinetic inhibitor; The binary copolymerization reaction temperature is 323.15-363.15K, and the reaction time is 5-12h; The molar ratio of N-vinyl caprolactam to vinyl n-butyl ether is 9:1-1:

1.

4. The hydrate kinetics inhibition composition according to claim 3, wherein: The ethylenediamine compound is selected from one or a combination of two or more of N-ethylethylenediamine, N,N-dimethylethylenediamine and N,N'-dimethylethylenediamine.

5. The hydrate kinetics inhibition composition according to claim 3, wherein: The relative molecular mass of the hydrate kinetic inhibitor A is 1000-50000.

6. The hydrate kinetics inhibition composition according to claim 3, wherein: The hydrate kinetics inhibitor is hydrate kinetics inhibitor A.

7. The hydrate kinetics inhibition composition according to claim 3, wherein: In the preparation method of the hydrate kinetic inhibitor A, the amount of the initiator is 0.01%-0.5%, calculated based on the total weight of the N-vinyl caprolactam and vinyl n-butyl ether as 100%.

8. The hydrate kinetics inhibition composition according to claim 7, wherein: The initiator includes one or a combination of two or more of azobisisobutyronitrile, dimethyl azobisisobutyrate, azobisisoheptanenitrile and tert-butyl hydroperoxide.

9. The hydrate kinetics inhibition composition according to claim 3, wherein: In the preparation method of the hydrate kinetic inhibitor A, the amount of the terminator is 0.01%-0.1%, calculated based on the total weight of the N-vinyl caprolactam and vinyl n-butyl ether as 100%.

10. The hydrate kinetics inhibition composition according to claim 9, wherein: The terminator includes styrene, methacrylic acid or a combination of the two.

11. The hydrate kinetics inhibition composition according to claim 3, wherein: In the preparation method of the hydrate kinetic inhibitor A, the weight ratio of the solvent to the sum of the N-vinyl caprolactam and the vinyl n-butyl ether is 2-10:

1.

12. The hydrate kinetics inhibition composition according to claim 11, wherein: The solvent includes one or a combination of two or more of ethanol, isopropanol, N,N-dimethylformamide, and n-propanol.

13. Use of the hydrate kinetics inhibition composition according to any one of claims 3 to 12 for inhibiting hydrate formation during oil and gas development or transportation.

14. The use according to claim 13, wherein: The hydrate kinetics inhibition composition is applied to an oil-gas-water three-phase system or a gas-water two-phase system.

15. The use according to claim 14, wherein: The oil-gas-water three-phase system or the gas-water two-phase system has a pressure of 0.5-25 MPa and a temperature of -10°C to 30°C.

16. The use according to claim 13, wherein: Calculated based on the total weight of water in the system as 100%, the dosage of the hydrate kinetic inhibitor is 0.5-5.0wt%; the dosage of the ethylenediamine compound is 0.1-5.0wt%.

17. The use according to claim 16, wherein: The dosage of the ethylenediamine compound is 0.5-2.0 wt %.

18. The use according to claim 16, wherein: The usage of the ethylenediamine compound is 1.0wt%.

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