CN112358570A - Temperature-sensitive natural gas hydrate kinetic inhibitor and preparation method thereof - Google Patents
Temperature-sensitive natural gas hydrate kinetic inhibitor and preparation method thereof Download PDFInfo
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Abstract
The invention provides a temperature-sensitive natural gas hydrate kinetic inhibitor and a preparation method thereof, wherein the natural gas hydrate kinetic inhibitor is prepared by performing nucleophilic substitution reaction on N-vinylformamide and 2-bromoethyl ether to obtain a pre-polymerized monomer NE, and then performing free radical copolymerization on the pre-polymerized monomer NE and N-vinyl pyrrolidone. The invention also provides a preparation method of the temperature-sensitive hydrate kinetic inhibitor. The natural gas hydrate kinetic inhibitor is used for inhibiting the generation and growth of natural gas hydrate crystal nuclei, further inhibiting the coalescence and deposition of natural gas hydrates in a shaft, preventing the shaft from being blocked by the natural gas hydrates, and simultaneously adjusting the rheological property of drilling fluid, thereby ensuring the safe and efficient production of the natural gas hydrates.
Description
Technical Field
The invention relates to a temperature-sensitive natural gas hydrate kinetic inhibitor and a preparation method thereof, belonging to the technical field of organic additives of water-based drilling fluids.
Background
The contradiction between the supply and demand of oil gas in China is increasingly prominent, the conventional oil gas resources cannot meet the increasing economic development requirements of the nation, and the development of efficient and clean new energy has important strategic significance for guaranteeing the energy safety of China. The natural gas hydrate is used as a clean resource with high heat value and huge reserve, and the hydrate resource amount of the sea area of China is about 800 million tons of oil equivalent, so that the natural gas hydrate is expected to become one of novel clean energy sources for replacing oil and gas resources in the future. However, natural gas hydrates present a series of key technical problems during drilling: the natural gas hydrate is easy to generate in a well bore, aggregates and causes the well bore to be blocked, and even causes a drilling accident in severe cases.
At present, in the drilling and production process, a method for inhibiting the natural gas hydrate is mainly to add a hydrate thermodynamic inhibitor, such as methanol, ethylene glycol, salt electrolyte and the like, into the drilling fluid, and to avoid the formation of the hydrate in a shaft by changing the thermodynamic conditions for forming the natural gas hydrate. However, the thermodynamic inhibitor has the defects of high dosage, poor effect and the like, for example, the dosage of methanol, ethanol, sodium chloride and the like is up to 20-60 wt%, so that the development cost of the natural gas hydrate is greatly increased, and chemical reagents such as methanol, ethylene glycol and the like can cause secondary damage to marine ecological environment; the salt electrolytes such as sodium chloride and the like have high corrosivity on drilling tools, even cause accidents such as pipeline breakage and the like in serious cases, and bring great risk to the production safety of the natural gas hydrate. Thus, existing thermodynamic inhibitors have failed to meet the further needs of sea natural gas hydrate development.
The natural gas hydrate kinetic inhibitor is a low-dose inhibitor which can inhibit the generation and growth of hydrate by influencing the kinetic parameters of the hydrate, does not need to change the phase equilibrium condition of the generation of the hydrate, and can greatly prolong the nucleation time of the hydrate, reduce the growth rate of crystal nuclei and reduce the blockage of the hydrate in the drilling process when the using amount is less than 3.0 wt% of the total amount of a system. Compared with the traditional thermodynamic inhibition method, the hydrate kinetic inhibitor has the advantages of small dosage, obvious effect, good environmental benefit and the like, can effectively inhibit the formation and deposition of hydrates in a shaft, and can provide powerful guarantee for safely and efficiently exploiting hydrate resources.
In addition, in the drilling and production process of the natural gas hydrate, when the drilling fluid circularly flows through a deep-water seabed area (below 4 ℃), the viscosity of the drilling fluid is sharply increased, so that the rheological property of the annular drilling fluid is difficult to control in the drilling process, the circulating resistance in a pipe column is increased, and the drilling and production safety of the natural gas hydrate is seriously threatened.
The patent literature also reports about the kinetic inhibitor of natural gas hydrate. For example: chinese patent document CN105859963A provides a polycyclic polymerized natural gas hydrate kinetic inhibitor, which is prepared by free radical polymerization using N-vinyl pyrrolidone, N-vinyl caprolactam, acrylamide and acrylonitrile, and can effectively inhibit the generation of natural gas hydrate, but the kinetic inhibitor can not control the rheological property of drilling fluid under the condition of low temperature; chinese patent document CN108276512A provides a temperature-sensitive polymer, which uses vinyl caprolactam monomer (VCL) to prepare a high molecular weight Polymer (PVCL) capable of controlling the rheological property of the drilling fluid by radical polymerization, but because it only contains a ring structure, the hydrate inhibition performance is weak.
Chinese patent document CN111116797A provides a novel natural gas hydrate inhibitor, which is obtained by adding a new structural group to a monomer ring structure of N-vinyl pyrrolidone, wherein the structural group is a hydroxyl group containing C1-C6, a hydrocarbon group containing C1-C6 or an amino group containing C1-C6. Chinese patent document CN109735316A provides a natural gas hydrate inhibitor. The natural gas hydrate inhibitor is prepared by adding-CF at the end group through chemical synthesis based on N-vinyl pyrrolidone3or-RCF3The end chain structure of the inhibitor is changed by the group, so that the aim of enhancing the inhibition effect is fulfilled. However, the above two inhibitors only contain a multi-element ring structure in a repeating unit, do not contain a linear structure, have single hydrate inhibition type and insufficient inhibition capability. Meanwhile, the drilling fluid is only used for inhibiting the generation of natural gas hydrate, but the rheological control effect of the drilling fluid is poor, and the current hydrate formation development requirement is not met.
Therefore, it is necessary to develop a kinetic inhibitor of natural gas hydrate which can effectively inhibit the formation of natural gas hydrate and can adjust the rheological property of the drilling fluid under low temperature conditions. The invention is therefore proposed.
Disclosure of Invention
Aiming at the defects of the prior art, the invention provides a temperature-sensitive natural gas hydrate kinetic inhibitor and a preparation method thereof. The natural gas hydrate kinetic inhibitor can effectively inhibit the generation and growth of natural gas hydrate crystal nuclei, thereby further inhibiting the coalescence and deposition of natural gas hydrates in a shaft and preventing the natural gas hydrates from blocking the shaft; meanwhile, the rheological property of the drilling fluid can be adjusted, so that the safe and efficient production of the natural gas hydrate is guaranteed.
The technical scheme of the invention is as follows:
a temperature-sensitive natural gas hydrate kinetic inhibitor is prepared by performing nucleophilic substitution reaction on N-vinylformamide and 2-bromoethyl ether to obtain a pre-polymerized monomer NE, and then performing free radical copolymerization on the pre-polymerized monomer NE and N-vinyl pyrrolidone, wherein the temperature-sensitive natural gas hydrate kinetic inhibitor has a structure shown in the following formula I:
in the formula I, m/n is 0.5-3.0.
According to the invention, the number average molecular weight of the temperature-sensitive natural gas hydrate kinetic inhibitor is preferably 10000-30000, and more preferably 25000-30000.
According to the invention, the preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor comprises the following steps:
(1) uniformly mixing N-vinylformamide, 2-bromoethyl ether and N, N-dimethylformamide, and stirring to obtain a mixed solution;
(2) heating the mixed solution obtained in the step (1) to 50-60 ℃, then adding an initiator, and stirring for reaction; after the reaction is finished, obtaining N-vinylformamide grafted diethyl ether prepolymerized monomer NE by extraction and purification;
(3) and (3) adding the N-vinylformamide grafted ether prepolymerization monomer NE, N-vinyl pyrrolidone and an initiator obtained in the step (2) into water, reacting at 50-70 ℃ in a nitrogen atmosphere, and drying the obtained product to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor.
According to the invention, the mass of the N-vinyl formamide in the step (1) is preferably 3-10% of the total mass of the N-vinyl formamide, the 2-bromoethyl ether and the N, N-dimethylformamide; the mass of the 2-bromoethyl ether is 5-20% of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide; the mass of the N, N-dimethylformamide is 70-85% of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide.
According to the invention, the mixing temperature in the step (1) is preferably 0-2 ℃; the stirring speed of the stirring is 200-500 r/min, the stirring temperature is 0-2 ℃, and the stirring time is 4-6 hours.
According to the invention, preferably, the initiator in the step (2) is azobisisobutyronitrile, and the addition amount of the initiator is 0.1-0.5 per mill of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide.
According to the invention, the stirring speed of the stirring reaction in the step (2) is preferably 200-500 r/min, and the reaction time is preferably 8-16 hours.
According to the present invention, preferably, the extraction and purification steps in step (2) are: cooling the reaction system to room temperature, adding a mixed solvent of N-hexane, ethyl acetate and water for extraction, washing the obtained organic phase with water, drying the organic phase with anhydrous magnesium sulfate, removing the solvent, and purifying the obtained product by silica gel column chromatography to obtain an N-vinylformamide grafted diethyl ether prepolymerization monomer NE;
further preferably, the volume ratio of n-hexane to ethyl acetate in the mixed solvent is 1: 4; the volume ratio of the total volume of the n-hexane and the ethyl acetate to the water is 1: 1-4; the ratio of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide to the volume of the mixed solvent is 1g: 3-9 mL;
further preferably, the eluent for column chromatography is a mixed solvent of n-hexane and ethyl acetate, wherein the volume ratio of n-hexane to ethyl acetate is 1: 4.
According to the invention, preferably, the mass of the N-vinylformamide grafted diethyl ether pre-polymerized monomer NE in the step (3) is 7-25% of the total mass of the N-vinylformamide grafted diethyl ether pre-polymerized monomer NE, N-vinylpyrrolidone and water; the mass of the N-vinyl pyrrolidone is 10-20% of the total mass of N-vinylformamide grafted diethyl ether prepolymerization monomer NE, N-vinyl pyrrolidone and water; the mass of the water is 55-83% of the total mass of the N-vinylformamide grafted diethyl ether prepolymerization monomer NE, the N-vinyl pyrrolidone and the water.
According to the invention, preferably, the initiator in the step (3) is azobisisobutyronitrile, and the addition amount of the initiator is 0.1-1 per mill of the total mass of the N-vinylformamide grafted diethyl ether prepolymerization monomer NE, the N-vinylpyrrolidone and the water.
According to the invention, the reaction time in the step (3) is preferably 4-6 hours; the drying is carried out for 10-12 hours at the temperature of 30-50 ℃ under vacuum.
According to the invention, the N-vinylformamide-grafted diethyl ether prepolymerized monomer NE obtained in step (2) has the structure shown in formula II:
the invention has the following technical characteristics and beneficial effects:
1. the natural gas hydrate kinetic inhibitor can inhibit the generation of natural gas hydrate and adjust the rheological property of drilling fluid. The preparation method comprises the steps of carrying out nucleophilic substitution reaction on N-vinylformamide and 2-bromoethyl ether to obtain a pre-polymerized monomer, carrying out free radical copolymerization on the pre-polymerized monomer and N-vinyl pyrrolidone to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor, wherein the obtained temperature-sensitive natural gas hydrate kinetic inhibitor has a five-membered ring containing an amido group and a linear structure containing the amido group, and the amido group can form a hydrogen bond with water molecules in the hydrate generation process to prevent the hydrates from forming a cage structure; in the growth process of the hydrate, the five-membered ring can be embedded into a hydrate cage structure to form steric hindrance, so that the hydrate grows abnormally or cannot grow, the hydrate is inhibited from gathering, the hydrate is prevented from blocking a shaft, and the safety and high efficiency of hydrate drilling construction are guaranteed.
2. The temperature-sensitive natural gas hydrate kinetic inhibitor provided by the invention has the advantages that N-vinylformamide grafted ether chain links exist, the proportion of hydrophilic groups in polymer molecules is increased, and the hydrophilicity of the polymer is enhanced, so that the temperature sensitivity of the inhibitor is enhanced, the control capability of the temperature-sensitive natural gas hydrate kinetic inhibitor on the rheological property of drilling fluid is increased, and a good steady flow effect is achieved on the drilling fluid. Experiments prove that when the temperature rises, the viscosity of the water-based drilling fluid containing the temperature-sensitive polymer is higher than that of the conventional water-based drilling fluid, and the viscosity change amplitude of the water-based drilling fluid system added with the temperature-sensitive natural gas hydrate kinetic inhibitor is smaller than that of the conventional water-based drilling fluid at 0-50 ℃, so that the temperature-sensitive polymer can effectively adjust the rheological property of the water-based drilling fluid system.
3. The temperature-sensitive natural gas hydrate kinetic inhibitor can inhibit the generation of hydrates in a shaft, and regulate and control the rheological property of a water-based drilling fluid system so as to reduce the use of thermodynamic inhibitors and drilling fluid flow pattern additives. The method can reduce the drilling cost while ensuring the safety of the natural gas hydrate drilling, and has higher economic value and use value.
Drawings
FIG. 1 is an infrared spectrum of the temperature sensitive kinetic inhibitor of natural gas hydrate prepared in example 1.
FIG. 2 is a graph of viscosity versus temperature for the water-based drilling fluids of test example 1 with the addition of the inhibitor prepared in example 1 and comparative example 1 and for the water-based drilling fluid without the addition of the inhibitor.
FIG. 3 is a graph showing the change of the internal pressure of the autoclave with time without adding an inhibitor in test example 2, wherein the abscissa is time and the ordinate is pressure.
FIG. 4 is a graph showing the growth of pure water hydrate in test example 2 without addition of an inhibitor, wherein the abscissa is time and the ordinate is the hydrate thickness.
FIG. 5 is a graph showing the change of the in vivo pressure of the autoclave with time after the addition of the inhibitor prepared in example 1 in test example 2, wherein the abscissa is time and the ordinate is pressure.
FIG. 6 is a graph showing the growth of the hydrate in Experimental example 2 after addition of the inhibitor prepared in example 1, wherein the abscissa is time and the ordinate is the thickness of the hydrate.
FIG. 7 is a graph showing the change of the in vivo pressure of the autoclave with time after the addition of the inhibitor prepared in comparative example 1 in test example 2, wherein the abscissa is time and the ordinate is pressure.
Detailed Description
The present invention is further illustrated by, but not limited to, the following examples.
Meanwhile, the experimental methods described in the following examples are all conventional methods unless otherwise specified; the reagents, materials and equipment are commercially available, unless otherwise specified.
Example 1
A preparation method of a temperature-sensitive natural gas hydrate kinetic inhibitor comprises the following steps:
(1) 6g N-vinylformamide, 6g of 2-bromoethyl ether and 48g N, N-dimethylformamide are uniformly mixed at 0 ℃, and stirred for 4 hours at the temperature of 0 ℃ and the stirring speed of 200r/min to obtain a mixed solution.
(2) Heating the mixed solution obtained in the step (1) to 50 ℃, then adding 0.03g of initiator azobisisobutyronitrile, and stirring and reacting for 8 hours under the condition that the stirring speed is 200 r/min; after the reaction is finished, cooling the reaction system to room temperature, adding 400mL of a mixed solvent of N-hexane, ethyl acetate and water (the volume ratio of the N-hexane to the ethyl acetate is 1:4, and the volume ratio of the total volume of the N-hexane and the ethyl acetate to the water is 1: 3) for extraction, washing the obtained organic phase with water, drying the organic phase with anhydrous magnesium sulfate, removing the solvent, purifying the obtained product by using the mixed solvent of the N-hexane and the ethyl acetate (the volume ratio of the N-hexane to the ethyl acetate is 1:4) as an eluent through silica gel (200 meshes and 300 meshes) column chromatography, removing the solvent, and drying the product in vacuum at 50 ℃ for 12 hours to obtain the N-vinyl formamide grafted prepolymerized ether monomer NE.
(3) Adding 6g of N-vinylformamide grafted ether prepolymerization monomer NE obtained in the step (2), 8g of vinyl pyrrolidone, 0.06g of initiator azobisisobutyronitrile and 46g of water into a three-neck flask provided with a thermometer, a mechanical stirring and reflux condenser tube, and reacting for 4 hours at 50 ℃ under a high-purity nitrogen atmosphere; and after the reaction is finished, drying the obtained product at 50 ℃ for 12h in vacuum to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor.
Infrared spectroscopic analysis was performed on the temperature-sensitive kinetic inhibitor synthesized in this example using an IRTracer-100 type Infrared spectrometer (KBr pellet) from Shimadzu corporation, Japan, and the results are shown in FIG. 1. As can be seen from FIG. 1, the infrared spectrum of the synthesized product is 3431.3cm-1，1678.0cm-1，1421.5cm-1Corresponding to characteristic peaks of N-H stretching vibration, C ═ O stretching vibration and C-N stretching vibration in amide group, respectively, 2981.9cm-1Corresponding to C-H stretching vibration in alkyl group, 1122.5cm-1Corresponding to the characteristic peak of stretching vibration of ether bond in the branched chain. From the above analysis, it can be seen that each functional group corresponds to a characteristic peak of the functional group of the target product, indicating that the target product has been synthesized.
Example 2
A preparation method of a temperature-sensitive natural gas hydrate kinetic inhibitor comprises the following steps:
(1) 6g N-vinylformamide, 12g of 2-bromoethyl ether and 42g N, N-dimethylformamide are uniformly mixed at 0 ℃, and stirred for 4 hours at the temperature of 0 ℃ and the stirring speed of 200r/min to obtain a mixed solution.
(2) Heating the mixed solution obtained in the step (1) to 50 ℃, then adding 0.03g of initiator azobisisobutyronitrile, and stirring and reacting for 8 hours under the condition that the stirring speed is 200 r/min; after the reaction is finished, cooling the reaction system to room temperature, adding 400mL of a mixed solvent of N-hexane, ethyl acetate and water (the volume ratio of the N-hexane to the ethyl acetate is 1:4, and the volume ratio of the total volume of the N-hexane and the ethyl acetate to the water is 1: 3) for extraction, washing the obtained organic phase with water, drying the organic phase with anhydrous magnesium sulfate, removing the solvent, purifying the obtained product by using the mixed solvent of the N-hexane and the ethyl acetate (the volume ratio of the N-hexane to the ethyl acetate is 1:4) as an eluent through silica gel (200 meshes and 300 meshes) column chromatography, removing the solvent, and drying the product in vacuum at 50 ℃ for 12 hours to obtain the N-vinyl formamide grafted prepolymerized ether monomer NE.
(3) Adding 6g of N-vinylformamide grafted ether prepolymerization monomer NE obtained in the step (2), 8g of vinyl pyrrolidone, 0.06g of initiator azobisisobutyronitrile and 46g of water into a three-neck flask provided with a thermometer, a mechanical stirring and reflux condenser tube, and reacting for 4 hours at 60 ℃ under a high-purity nitrogen atmosphere; and after the reaction is finished, drying the obtained product at 50 ℃ for 12h in vacuum to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor.
Example 3
A preparation method of a temperature-sensitive natural gas hydrate kinetic inhibitor comprises the following steps:
(1) 6g N-vinylformamide, 10g of 2-bromoethyl ether and 44g N, N-dimethylformamide are uniformly mixed at 0 ℃, and stirred for 4 hours at the temperature of 0 ℃ and the stirring speed of 200r/min to obtain a mixed solution.
(2) Heating the mixed solution obtained in the step (1) to 50 ℃, then adding 0.03g of initiator azobisisobutyronitrile, and stirring and reacting for 8 hours under the condition that the stirring speed is 200 r/min; after the reaction is finished, cooling the reaction system to room temperature, adding 200mL of a mixed solvent of N-hexane, ethyl acetate and water (the volume ratio of the N-hexane to the ethyl acetate is 1:4, and the volume ratio of the total volume of the N-hexane and the ethyl acetate to the water is 1: 3) for extraction, washing the obtained organic phase with water, drying the organic phase with anhydrous magnesium sulfate, removing the solvent, purifying the obtained product by using the mixed solvent of the N-hexane and the ethyl acetate (the volume ratio of the N-hexane to the ethyl acetate is 1:4) as an eluent through silica gel (200 meshes and 300 meshes) column chromatography, removing the solvent, and drying the product in vacuum at 50 ℃ for 12 hours to obtain the N-vinyl formamide grafted prepolymerized ether monomer NE.
(3) Adding 6g of N-vinylformamide grafted ether prepolymerization monomer NE obtained in the step (2), 8g of vinyl pyrrolidone, 0.06g of initiator azobisisobutyronitrile and 46g of water into a three-neck flask provided with a thermometer, a mechanical stirring and reflux condenser tube, and reacting for 4 hours at 70 ℃ under a high-purity nitrogen atmosphere; and after the reaction is finished, drying the obtained product at 50 ℃ for 12h in vacuum to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor.
Comparative example 1
A preparation method of a polyvinylpyrrolidone inhibitor comprises the following steps:
38.994g of water is added into a three-neck flask and then stirred, 11g N-vinyl pyrrolidone is added under the protection of nitrogen, the temperature is raised to 70 ℃, 0.0006g of initiator azobisisobutyronitrile is added after stirring for 30 minutes, and the mixture is uniformly mixed; after 8h of reaction, the obtained product is dried in vacuum at 90 ℃ for 12h to obtain the polyvinylpyrrolidone inhibitor.
Test example 1
2g of the temperature-sensitive natural gas hydrate kinetic inhibitor prepared in example 1 and 2g of the polyvinylpyrrolidone inhibitor prepared in comparative example 1 were added to 400mL of a 4% bentonite, 0.5% XC (xanthan gum), 1% DSP-1 and 10% NaCl water-based drilling fluid system (the% is mass percent), the water-based drilling fluid and the water-based drilling fluid after the addition of the inhibitor were tested for their rheological properties at different temperatures by using a low-temperature rheometer, and the results are shown in fig. 2 by using the water-based drilling fluid without the addition of the inhibitor as a comparison. As can be seen from the figure 2, the change amplitude of the apparent viscosity of the water-based drilling fluid without the inhibitor is more than 65% within the range of 0-50 ℃; the change amplitude of the apparent viscosity of the drilling fluid is less than 50% after the inhibitor prepared in example 1 is added; when the polyvinylpyrrolidone inhibitor prepared in the comparative example 1 is added, the apparent viscosity change amplitude of the drilling fluid is smaller than that of the water-based drilling fluid without the inhibitor, but is larger than that of the drilling fluid after the inhibitor prepared in the example 1 is added. Therefore, the natural gas hydrate kinetic inhibitor prepared by the invention better realizes the control of the rheological property of the drilling fluid and meets the rheological property requirement of the drilling fluid during the development of hydrate stratum.
Test example 2
The natural gas hydrate kinetic inhibitors prepared in example 1 and comparative example 1 were tested for natural gas hydrate inhibition performance by the following specific steps:
and (3) testing by using a hydrate experimental device, wherein before the experiment, the kettle body is washed three times by using deionized water and ethanol in sequence, and before the methane gas is filled into the kettle body, the kettle body is vacuumized for half an hour. Respectively adding 220g of pure water, 220g of pure water and 1.1g of the inhibitor prepared in the embodiment 1 into the kettle body, circularly cooling to the temperature of the kettle body of 13.4 ℃, introducing methane gas, and recording the growth process of the hydrate and the pressure change in the kettle body; in addition, by comparing the inhibitor prepared in comparative example 1, 220g of pure water +1.1g of the inhibitor prepared in comparative example 1 was added to the tank, and circulated and cooled to a tank temperature of 13.4 ℃ to record the change in pressure in the tank in the presence of the polyvinylpyrrolidone (PVP) inhibitor of comparative example 1.
The pressure change in the autoclave body and the growth situation of the pure water hydrate under the condition of not adding the inhibitor are respectively shown in figures 3 and 4; the pressure change in the kettle body after the inhibitor prepared in the example 1 is added and the growth situation of the hydrate are respectively shown in figures 5 and 6; the graph of the change in the in-vivo pressure after the addition of the inhibitor prepared in comparative example 1 is shown in FIG. 7. As can be seen by comparing FIGS. 3, 5 and 7, the induction time of pure water hydrate is 1min at the shortest time, the induction time of hydrate is 102min after the inhibitor prepared in example 1 is added, and the induction time of hydrate is 61min after the polyvinylpyrrolidone inhibitor prepared in comparative example 1 is added, when the initial pressure is about 10 MPa. From the graphs 4 and 6, the hydrate induction time and the hydrate generation rate can be intuitively reflected, and the comparison shows that the hydrate induction time is obviously prolonged and the hydrate generation rate is greatly reduced after the inhibitor prepared by the embodiment of the invention is added, so that the inhibitor provided by the invention has good hydrate generation inhibiting capability and is suitable for being used as a hydrate inhibitor for drilling fluid in the hydrate exploitation and drilling process.
Claims (10)
1. The temperature-sensitive natural gas hydrate kinetic inhibitor is characterized by being prepared by performing nucleophilic substitution reaction on N-vinylformamide and 2-bromoethyl ether to obtain a pre-polymerized monomer NE, and then performing free radical copolymerization on the pre-polymerized monomer NE and N-vinyl pyrrolidone, wherein the temperature-sensitive natural gas hydrate kinetic inhibitor has a structure shown in the following formula I:
in the formula I, m/n is 0.5-3.0.
2. The temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 1, wherein the number average molecular weight of the temperature-sensitive natural gas hydrate kinetic inhibitor is 10000-30000, preferably 25000-30000.
3. The method for preparing a temperature-sensitive natural gas hydrate kinetic inhibitor according to any one of claims 1 to 2, comprising the steps of:
(1) uniformly mixing N-vinylformamide, 2-bromoethyl ether and N, N-dimethylformamide, and stirring to obtain a mixed solution;
(2) heating the mixed solution obtained in the step (1) to 50-60 ℃, then adding an initiator, and stirring for reaction; after the reaction is finished, obtaining N-vinylformamide grafted diethyl ether prepolymerized monomer NE by extraction and purification;
(3) and (3) adding the N-vinylformamide grafted ether prepolymerization monomer NE, N-vinyl pyrrolidone and an initiator obtained in the step (2) into water, reacting at 50-70 ℃ in a nitrogen atmosphere, and drying the obtained product to obtain the temperature-sensitive natural gas hydrate kinetic inhibitor.
4. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the mass of the N-vinylformamide in the step (1) is 3-10% of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide; the mass of the 2-bromoethyl ether is 5-20% of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide; the mass of the N, N-dimethylformamide is 70-85% of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide.
5. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the mixing temperature in the step (1) is 0-2 ℃; the stirring speed of the stirring is 200-500 r/min, the stirring temperature is 0-2 ℃, and the stirring time is 4-6 hours.
6. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the initiator in the step (2) is azobisisobutyronitrile, and the addition amount of the initiator is 0.1-0.5 per mill of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide; the stirring speed of the stirring reaction is 200-500 r/min, and the reaction time is 8-16 hours.
7. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the extraction and purification steps in the step (2) are as follows: cooling the reaction system to room temperature, adding a mixed solvent of N-hexane, ethyl acetate and water for extraction, washing the obtained organic phase with water, drying the organic phase with anhydrous magnesium sulfate, removing the solvent, and purifying the obtained product by silica gel column chromatography to obtain the N-vinylformamide grafted ethyl ether prepolymerized monomer NE.
8. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 7, wherein the volume ratio of n-hexane to ethyl acetate in the mixed solvent is 1:4, and the volume ratio of the total volume of n-hexane and ethyl acetate to water is 1: 1-4; the ratio of the total mass of the N-vinylformamide, the 2-bromoethyl ether and the N, N-dimethylformamide to the volume of the mixed solvent is 1g: 3-9 mL; the eluent for the column chromatography is a mixed solvent of n-hexane and ethyl acetate, wherein the volume ratio of the n-hexane to the ethyl acetate is 1: 4.
9. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the mass of the N-vinylformamide-grafted-ether pre-polymerized monomer NE in the step (3) is 7-25% of the total mass of the N-vinylformamide-grafted-ether pre-polymerized monomer NE, N-vinylpyrrolidone and water; the mass of the N-vinyl pyrrolidone is 10-20% of the total mass of N-vinylformamide grafted diethyl ether prepolymerization monomer NE, N-vinyl pyrrolidone and water; the mass of the water is 55-83% of the total mass of the N-vinylformamide grafted ether prepolymerization monomer NE, the N-vinyl pyrrolidone and the water; the addition amount of the initiator is 0.1-1 per mill of the total mass of the N-vinylformamide grafted ether prepolymerization monomer NE, the N-vinylpyrrolidone and the water.
10. The preparation method of the temperature-sensitive natural gas hydrate kinetic inhibitor according to claim 3, wherein the reaction time in the step (3) is 4-6 hours; the drying is carried out for 10-12 hours at the temperature of 30-50 ℃ under vacuum.
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Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040030206A1 (en) * | 2000-12-01 | 2004-02-12 | Uwe Dahlmann | Additives for inhibiting the formation of gas hydrates |
| CN106907573A (en) * | 2017-03-01 | 2017-06-30 | 西南石油大学 | A kind of kinetic inhibitor, preparation method and inhibitor |
| CN108070063A (en) * | 2017-12-29 | 2018-05-25 | 中国科学院广州能源研究所 | A kind of vinylamide based block copolymer hydrate dynamic inhibitor and preparation method and application |
| CN109776723A (en) * | 2018-12-26 | 2019-05-21 | 中国科学院广州能源研究所 | A kind of amide analog copolymer hydrate dynamic inhibitor and its application |
-
2020
- 2020-11-09 CN CN202011238870.4A patent/CN112358570B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040030206A1 (en) * | 2000-12-01 | 2004-02-12 | Uwe Dahlmann | Additives for inhibiting the formation of gas hydrates |
| CN106907573A (en) * | 2017-03-01 | 2017-06-30 | 西南石油大学 | A kind of kinetic inhibitor, preparation method and inhibitor |
| CN108070063A (en) * | 2017-12-29 | 2018-05-25 | 中国科学院广州能源研究所 | A kind of vinylamide based block copolymer hydrate dynamic inhibitor and preparation method and application |
| CN109776723A (en) * | 2018-12-26 | 2019-05-21 | 中国科学院广州能源研究所 | A kind of amide analog copolymer hydrate dynamic inhibitor and its application |
Non-Patent Citations (1)
| Title |
|---|
| RYO KAWATANI等: "Synthesis of Thermosensitive Poly(N‑vinylamide) Derivatives Bearing Oligo Ethylene Glycol Chain for Kinetic Hydrate Inhibitor", 《MACROMOLECULES》 * |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116948090A (en) * | 2023-07-04 | 2023-10-27 | 中国石油大学(华东) | Preparation method and application of natural gas hydrate reservoir temperature-sensitive self-blocking removal reservoir protective agent |
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