Degradable adhesive with reversible adhesion effect as well as preparation method and application thereof

Abstract

The invention provides a degradable adhesive with a reversible adhesion effect and a preparation method and application of the degradable adhesive with the reversible adhesion effect. The raw materials comprise any three or four of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin, a metacrylic acid ester functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane, and the silyl-protected phenol contains a fluoride responsive degradation functional group; the mass ratio of the silyl-protected phenol to the hydrogenated hydroxyl-terminated polyolefin resin to the metacrylic acid ester functionalized pyrazole derivative to the biomass-based isocyanate-based polyurethane is (25-90): (10-80): (25-75): (20-70). The degradable adhesive with the reversible adhesion effect can realize repeated high-strength adhesion with a metal wall surface of a shaft, also has a better degradation effect, and can fully react with a blockage removing liquid under the condition of formation temperature to achieve the purpose of removing blockage of the shaft.

Description

TECHNICAL FIELD

[0001] The present application relates to a degradable adhesive with reversible adhesion effect and its preparation method and application, and belongs to the field of shale gas reservoir development and drilling and production technology. BACKGROUND

[0002] In the development of oil and gas fields, in order to improve the yield of oil wells, it is often necessary to carry out fracturing operation, that is, by injecting high-pressure liquid into the wellbore, cracks are generated in the formation, thereby increasing the permeability of oil and gas. However, in some cases, the wellbore may be deformed or the tool may be difficult to enter the well, etc., which causes the conventional segmented fracturing modification technology to be unable to be implemented. At this time, temporary plugging technology needs to be used to plug the wellbore to force the fluid to turn and generate new cracks or branch cracks to solve these problems.

[0003] Lost circulation is one of the common problems in workover engineering, which has a great impact on the smooth progress of workover operations and the exploitation of oil and gas resources. In order to solve the problem of lost circulation, wellbore temporary plugging needs to be carried out. The main purpose of wellbore temporary plugging is to control the leakage of wellbore fluid, protect the formation from pollution, and ensure the smooth progress of workover operations.

[0004] The existing wellbore temporary plugging materials are mainly gels, cements or resin materials. Among them, the adhesion strength of the resin material after solidification to the metal wall surface is low, and it cannot be degraded. The cement material has strong pressure-bearing capacity, but still faces the problem of ineffective degradation. The gel material faces the problem of insufficient pressure-bearing capacity. It can be seen that the existing wellbore temporary plugging materials cannot meet the degradation performance and pressure-bearing performance.

[0005] Therefore, it has become a technical problem urgently to be solved in the field to provide a new degradable adhesive with reversible adhesion effect and its preparation method and application. SUMMARY

[0006] In order to solve the above-mentioned shortcomings and deficiencies, the purpose of the present application is to provide a degradable adhesive with reversible adhesion effect and its preparation method and application. The degradable adhesive with reversible adhesion effect can realize repeated high-strength adhesion to the metal wall surface of the wellbore, and it also has good degradation effect, can fully react with the plug-removing fluid under the temperature condition of the formation, and achieve the purpose of removing the wellbore plugging.

[0007] To achieve the above object, in one aspect, the present application provides a degradable adhesive with reversible adhesion effect, wherein the degradable adhesive with reversible adhesion effect is prepared by reaction of raw materials, wherein the raw materials include any three or four of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin (hydrogenated hydroxyl-terminated polyolefin resin), methacrylate functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane, and the silyl-protected phenol contains fluoride-responsive degradation functional groups.

[0008] The mass ratio of the silyl-protected phenol, the hydrogenated hydroxyl-terminated polyolefin resin, the methacrylate functionalized pyrazole derivative and the biomass-based isocyanate-based polyurethane is 25-90:10-80:25-75:20-70. That is, when the raw materials include the four substances of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin, methacrylate functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane, the mass ratio of the four substances is 25-90:10-80:25-75:20-70; when the raw materials include any three of the four substances, the mass ratio of the any three substances also meets the above mass ratio requirement, such as when the raw materials include silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin and methacrylate functionalized pyrazole derivative, the mass ratio of the three is 25-90:10-80:25-75.

[0009] As a specific embodiment of the above degradable adhesive of the present application, wherein the biomass-based isocyanate-based polyurethane is prepared by reaction of modified castor oil, polyol and bio-based aliphatic isocyanate as raw materials under the catalysis of a catalyst;

[0010] Wherein, the mass ratio of modified castor oil, polyol, bio-based aliphatic isocyanate and catalyst is 5-25:20-40:70-85:0.1-0.8.

[0011] As a specific embodiment of the above degradable adhesive of the present application, wherein in the preparation process of the biomass-based isocyanate-based polyurethane, the temperature of the reaction is 45-60℃, and the time is 1-4h.

[0012] As a specific embodiment of the above degradable adhesive of the present application, wherein the biomass-based isocyanate-based polyurethane is prepared by a preparation method comprising the following specific steps:

[0013] Step 1): mixing bio-based aliphatic isocyanate, polyol and part of the catalyst and reacting at 45-60℃ for 1-2h;

[0014] Step 2): continue the reaction at 45-60℃ for 1-2h after adding modified castor oil and another part of catalyst to obtain biomass-based isocyanate-based polyurethane.

[0015] The preparation method of the biomass-based isocyanate-based polyurethane described above further comprises step 3): cleaning and purifying the product obtained after step 2) to remove possible residual reactants, catalysts and impurities, etc. to obtain the biomass-based isocyanate-based polyurethane.

[0016] In the preparation method of the biomass-based isocyanate-based polyurethane described above, modified castor oil, polyol, bio-based aliphatic isocyanate and catalyst are all conventional substances, which can be obtained by commercial purchase or prepared by existing conventional methods, and the specific substances of polyol, bio-based aliphatic isocyanate and catalyst are not specifically required in the present application, which can be reasonably selected according to the actual operation needs on site, as long as the purpose of preparing biomass-based isocyanate-based polyurethane can be achieved.

[0017] Among them, the selection and amount of polyol can significantly affect the flexibility and hardness of polyurethane. Shorter chain polyols (such as glycerol, propylene glycol, etc.) tend to produce soft polyurethane, while longer chain polyols (such as polyether polyols) increase the hardness and strength of polyurethane. By adjusting the type and proportion of polyol, the mechanical properties of polyurethane can be precisely controlled to meet different application requirements. For example, in some embodiments of the present application, the polyol can be glycerol, ethylene glycol or polyether polyol, etc.

[0018] Bio-based aliphatic isocyanate contains isocyanate groups, which can react with polyol and other reactants under the catalysis of suitable catalysts to form the main chain structure of polyurethane. For example, in some embodiments of the present application, the bio-based aliphatic isocyanate can be a product with model number HI-100 produced by Dongguan Delun New Material Co., Ltd., and the catalyst can be triethylamine, etc. In addition, the present application does not have requirements for the amount ratio of catalysts used in step 1) and step 2), as long as the total amount of the two meets the raw material amount ratio range when preparing biomass-based isocyanate-based polyurethane.

[0019] Modified castor oil contains abundant ricinoleic acid, which can react with isocyanate through ester exchange reaction and other methods. The double bond in ricinoleic acid can provide flexibility and elasticity, improving the tensile properties and wear resistance of the adhesive. In addition, modified castor oil, as a natural plant oil, has good biodegradability and biocompatibility. Its introduction into biomass-based isocyanate-based polyurethane can improve the biodegradability of the adhesive, making it easier to be degraded by the natural environment after use, and reducing the impact on the environment.

[0020] As a specific embodiment of the above-mentioned degradable adhesive of the present application, wherein the silyl-protected phenol has the following formula 1):

[0021]

[0022] As a specific embodiment of the above-mentioned degradable adhesive of the present application, wherein the silyl-protected phenol is obtained by reacting 2,6-bis(hydroxymethyl)-p-cresol and tert-butyldimethylsilyl chloride;

[0023] wherein the mass ratio of 2,6-bis(hydroxymethyl)-p-cresol and tert-butyldimethylsilyl chloride is 1-7:6-13, and the reaction temperature is 35-55℃, and the reaction time is 1-3h.

[0024] In addition to the two reactants of 2,6-bis(hydroxymethyl)-p-cresol and tert-butyldimethylsilyl chloride, an auxiliary material can also be used in the preparation of the silyl-protected phenol of the present application, and the auxiliary material includes N,N'-dimethylformamide, imidazole, methanol / ethyl ether mixture, and p-toluenesulfonic acid, etc., and in this case, the mass ratio of 2,6-bis(hydroxymethyl)-p-cresol, N,N'-dimethylformamide, imidazole, tert-butyldimethylsilyl chloride, methanol / ethyl ether mixture, and p-toluenesulfonic acid is 1-7:35-55:3-7:6-13:25-35:0.2-0.8. Among them, N,N'-dimethylformamide (DMF) is a polar organic solvent with good solubility, which can dissolve many organic and inorganic compounds. In the reaction for preparing the silyl-protected phenol, DMF can play the role of a solvent, which helps to dissolve the reactants and promote the reaction. The methanol / ethyl ether mixture can help to dissolve the reactants and intermediates, and promote the reaction. The mixed use of methanol and ethyl ether can adjust the polarity and solubility of the reaction system, which is conducive to the interaction of different types of reactants in the reaction. At the same time, imidazole and p-toluenesulfonic acid can promote the reaction and facilitate the generation of silyl-protected phenol.

[0025] The present application does not make specific requirements for the specific operation of preparing the above-mentioned silyl-protected phenol, and various different processes can be used for preparation. In order to further illustrate the silyl-protected phenol of the present application, a specific preparation method of the silyl-protected phenol is provided, which includes the following steps:

[0026] Step (1): Imidazole is added to the methanol / ethyl ether mixture and dissolved thoroughly;

[0027] Step (2): Slowly add tert-butyldimethylsilyl chloride;

[0028] Step (3): adding p-toluenesulfonic acid and N,N'-dimethylformamide and ensuring uniform mixing;

[0029] Step (4): slowly adding 2,6-bis(hydroxymethyl)-p-cresol and mixing it uniformly, and obtaining the silyl-protected phenol after the reaction is completed.

[0030] In step (1) of the above-mentioned method for preparing the silyl-protected phenol of the present application, the imidazole can be fully dissolved in the methanol / ethyl ether mixture by stirring, and the stirring also needs to be continued in steps (2) to (4) to ensure that the p-toluenesulfonic acid and N,N'-dimethylformamide in step (3) and the 2,6-bis(hydroxymethyl)-p-cresol in step (4) are mixed uniformly.

[0031] The above-mentioned method for preparing the silyl-protected phenol of the present application further comprises step (5): purifying the product by using extraction, filtration or distillation, etc. to obtain the silyl-protected phenol.

[0032] The 2,6-bis(hydroxymethyl)-p-cresol and the tert-butyldimethylsilyl chloride used in the preparation of the silyl-protected phenol of the present application are all conventional substances and can be commercially available. In addition, the present application does not make specific requirements for the ratio of methanol and ethyl ether in the methanol / ethyl ether mixture used in the preparation process, which can be reasonably adjusted according to the needs. For example, in some embodiments of the present application, the volume ratio of methanol and ethyl ether is 1:1.

[0033] As a specific embodiment of the above-mentioned degradable adhesive of the present application, the molecular formula of the methacrylate-functionalized pyrazole derivative is as shown in the following formula 2):

[0034]

[0035] In formula 2), R is -CH3, -CH(CH3)2 or -C(CH3)2.

[0036] As a specific embodiment of the above-mentioned degradable adhesive of the present application, the methacrylate-functionalized pyrazole derivative is prepared by esterification reaction of methacrylic acid and pyrazole-5-ol;

[0037] In which, the molecular formula of pyrazole-5-ol is as shown in the following formula 3):

[0038]

[0039] In formula 3), R is -CH3, -CH(CH3)2 or -C(CH3)2.

[0040] The mass ratio of methacrylic acid and pyrazole-5-ol is 25-35:30-45, the temperature of the reaction is 20-35℃, and the time is 0.5-4h.

[0041] In addition to the two reactants of methacrylic acid and pyrazole-5-ol, the auxiliary materials including N,N'-dicyclohexyl carbodiimide and 4-dimethylaminopyridine, etc. can be used in the preparation of the methacrylic ester functionalized pyrazole derivative of the present application, and the mass ratio of N,N'-dicyclohexyl carbodiimide, 4-dimethylaminopyridine, methacrylic acid and pyrazole-5-ol is 25-35:3-8:25-35:30-45. Among them, N,N'-dicyclohexyl carbodiimide and 4-dimethylaminopyridine can promote the esterification reaction, which is beneficial to the formation of the target product, i.e. the methacrylic ester functionalized pyrazole derivative.

[0042] The specific operation for preparing the above-mentioned methacrylic ester functionalized pyrazole derivative of the present application is not specifically required, and can be prepared by various different processes. In order to further illustrate the methacrylic ester functionalized pyrazole derivative of the present application, a specific preparation method of the methacrylic ester functionalized pyrazole derivative is provided, which comprises the following steps:

[0043] Step 1: After mixing methacrylic acid and N,N'-dicyclohexyl carbodiimide, the temperature of the system is controlled to be 20-35℃, and the system is kept at this temperature for 0.5-2h;

[0044] Step 2: Slowly add pyrazole-5-ol and mix it evenly;

[0045] Step 3: After adding 4-dimethylaminopyridine, the temperature of the system is controlled to be 20-35℃, and the system is kept at this temperature for 0.5-2h to obtain the methacrylic ester functionalized pyrazole derivative.

[0046] The steps 2 and 3 of the above-mentioned preparation method of the methacrylic ester functionalized pyrazole derivative need to be carried out under stirring conditions.

[0047] The above-mentioned preparation method of the methacrylic ester functionalized pyrazole derivative further comprises step 4: after the reaction is completed, the product is separated and purified by extraction, filtration and the like to obtain the target product, i.e. the methacrylic ester functionalized pyrazole derivative.

[0048] As a specific embodiment of the above-mentioned degradable adhesive of the present application, the pyrazole-5-ol is prepared by reacting 1,3-diketone derivative and monohydrate at a mass ratio of 45-50:55-60 at 65-80℃ for 3-5h;

[0049] The molecular formula of the 1,3-diketone derivative is shown in the following formula 4):

[0050]

[0051] In formula 4), R is -CH3, -CH(CH3)2 or -C(CH3)2.

[0052] As a specific embodiment of the above-mentioned degradable adhesive of the present application, in the preparation of the degradable adhesive with reversible adhesion effect, the reaction is first carried out at 75-85°C for 2-3h, and then the temperature is raised to 110-125°C for 1-3h.

[0053] The degradable adhesive with reversible adhesion effect provided by the present application is prepared by reaction of raw materials, wherein the raw materials include any three or four of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin (hydrogenated hydroxyl-terminated polyolefin resin), methacrylate-functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane, and the silyl-protected phenol contains fluoride-responsive degradation functional groups. The silyl-protected phenol containing fluoride-responsive degradation functional groups can make the degradable adhesive responsive to specific stimuli for degradation. When the degradable adhesive is exposed to an environment containing fluoride, these functional groups (mainly -Si-O- bonds) will be degraded under the stimulation of temperature (reaction temperature), thereby causing the decomposition and dissolution of the degradable adhesive. This controllable degradation helps the degradable adhesive to quickly release its adhesion effect when needed.

[0054] The hydroxyl functional groups of the hydrogenated hydroxyl-terminated polyolefin resin enable it to have hydrolysis reaction or form hydrogen bonding and other interactions with other raw materials used in the preparation of the degradable adhesive with reversible adhesion effect, thereby achieving adhesion effect, and this adhesion effect is reversible because these chemical bonds can be broken under suitable temperature conditions, thereby causing the decomposition of the adhesive and the disappearance of the adhesion effect.

[0055] The methacrylate-functionalized pyrazole derivative has a methacrylate structure and a pyrazole structure, which enables it to have hydrogen bonding, π-π stacking and other interactions with other raw materials used in the preparation of the degradable adhesive with reversible adhesion effect, thereby achieving reversible adhesion effect. This special molecular structure can endow the adhesive with the ability of reversible adhesion during the preparation of the degradable adhesive, so that the adhesive can realize the cycle process of adhesion and de-adhesion under suitable temperature conditions.

[0056] The isocyanate functional groups in the biomass-based isocyanate-based polyurethane can react with functional groups such as hydroxyl groups to form chemical bonds such as urea bonds, thereby realizing the adhesive effect of the adhesive. Under suitable conditions (for example, suitable temperature, humidity, etc.), these chemical bonds can be broken, resulting in the disappearance of the adhesive effect of the adhesive, thereby realizing reversible adhesion.

[0057] In another aspect, the present application also provides a preparation method of the above-mentioned degradable adhesive with reversible adhesion effect, wherein the preparation method comprises:

[0058] Any three or four of the silyl-protected phenol, the hydrogenated hydroxyl-terminated polyolefin resin, the methacrylate-functionalized pyrazole derivative and the biomass-based isocyanate-based polyurethane are taken in a use amount ratio and mixed, and then reacted, and the degradable adhesive with reversible adhesion effect is prepared after the reaction is completed.

[0059] In another aspect, the present application also provides the application of the above-mentioned degradable adhesive with reversible adhesion effect in the staged fracturing temporary plugging construction of a complex variable-diameter well or the plugging construction of a severe leakage well.

[0060] Compared with the prior art, the degradable adhesive with reversible adhesion effect provided by the present application can achieve the following beneficial technical effects:

[0061] (1) The degradable adhesive with reversible adhesion effect provided by the present application can effectively improve the bonding strength of the liquid bridge plug in the wellbore, and can realize the effect of high-strength bonding again through external stimulation such as heat pressing after the material is broken.

[0062] (2) The degradable adhesive with reversible adhesion effect provided by the present application can be effectively degraded into a liquid in an organic solvent, and is carried away from the wellbore in the form of circulating flushing in the wellbore.

[0063] (3) The degradable adhesive with reversible adhesion effect provided by the present application is used in the staged fracturing temporary plugging construction of a complex variable-diameter well or the plugging construction of a severe leakage well, which can optimize the temporary plugging process, improve the temporary plugging effect and the reservoir producing degree, and provide safer, more efficient and more environmentally friendly technical support for the development of oil and gas fields. DETAILED DESCRIPTION

[0064] It should be noted that the terms "comprising" and any variation thereof in the specification and claims of the present application are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not have to be limited to only those steps or units clearly listed, but can include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0065] The ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with the ranges. For example, a range of 60-120 and a range of 80-110 are understood to include the ranges of 60-110 and 80-120, as well as the individual endpoints 60, 80, 110, and 120. Also, a range of 1-2 and a range of 3-5 are understood to include the ranges of 1-5, 1-3, 2-5, 3-2, and 5-2, as well as the individual endpoints 1, 2, 3, 5, and 5.

[0066] In the present application, unless otherwise stated, the numerical range "a-b" indicates a shorthand for the inclusion of any and all expressed combinations of integers within the limits of a and b, wherein a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been individually listed in the present application, and "0-5" is merely a shorthand for these numerical combinations.

[0067] In the present application, all embodiments and preferred embodiments mentioned in the present application can be combined with each other to form new technical solutions, if not specifically stated.

[0068] In the present application, all technical features and preferred features mentioned in the present application can be combined with each other to form new technical solutions, if not specifically stated.

[0069] In the present application, all steps mentioned in the present application can be performed in sequence or randomly, but preferably in sequence, if not specifically stated. For example, the method comprises steps (a) and (b) indicates that the method can comprise steps (a) and (b) in sequence, or steps (b) and (a) in sequence. For example, the method further comprises step (c) indicates that step (c) can be added to the method in any order, for example, the method can comprise steps (a), (b) and (c), or steps (a), (c) and (b), or steps (c), (a) and (b), etc.

[0070] In order to make the objectives, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in combination with the accompanying tables and examples. The examples described below are part of the examples of the present application, rather than all the examples, and are only used to illustrate the present application, and should not be regarded as limiting the scope of the present application. Based on the examples in the present application, all other examples obtained by those of ordinary skill in the art without making creative efforts fall within the scope of protection of the present application. If the specific conditions are not specified in the examples, the conventional conditions or the conditions recommended by the manufacturer are used. If the reagents or instruments used are not specified by the manufacturer, they are all conventional products that can be purchased on the market.

[0071] Example 1

[0072] The present example provides a degradable adhesive with reversible adhesion effect, which is prepared by a preparation method comprising the following specific steps:

[0073] Preparation of biomass-based isocyanate-based polyurethane:

[0074] Step 1): After mixing the bio-based aliphatic isocyanate (product of Dongguan Delun New Material Co., Ltd., type HI-100), ethylene glycol and part of the triethylamine catalyst, the mixture is reacted at 60°C for 1h;

[0075] Step 2): After adding modified castor oil (purchased from Guangzhou Chufei Chemical Technology Co., Ltd.) and another part of the triethylamine catalyst, the reaction is continued at 60°C for 1h;

[0076] Step 3): The product obtained after step 2) is washed and purified to remove possible residual reactants, catalysts and impurities, etc., to obtain the biomass-based isocyanate-based polyurethane;

[0077] The mass ratio of modified castor oil, polyol, bio-based aliphatic isocyanate and catalyst is 5:20:74.5:0.5.

[0078] Preparation of silyl-protected phenol:

[0079] Step (1): Imidazole is added to a methanol / ethyl ether mixture (volume ratio of methanol to ethyl ether is 1:1) and is fully dissolved by stirring;

[0080] Step (2): Under stirring, tert-butyl dimethyl silyl chloride is slowly added;

[0081] Step (3): Under stirring, p-toluenesulfonic acid and N,N'-dimethylformamide are added and ensured to be uniformly mixed;

[0082] Step (4): under stirring, 2,6-bis(hydroxymethyl)-p-cresol is slowly added and mixed uniformly;

[0083] Step (5): after the reaction is completed, the product is purified by extraction, filtration or distillation, etc. to obtain the silyl-protected phenol;

[0084] The mass ratio of 2,6-bis(hydroxymethyl)-p-cresol, N,N'-dimethylformamide, imidazole, tert-butyl dimethylsilyl chloride, methanol / ethyl ether mixture and p-toluenesulfonic acid is 4.2:55:3:12:25:0.8, the temperature of the whole preparation process is maintained at 35℃, and the time is 2h.

[0085] Preparation of methacrylate functionalized pyrazole derivative:

[0086] First, pyrazole-5-ol is prepared, and the preparation method comprises: taking 45% of 1,3-diketone derivative and 55% of monohydrate hydrazine based on the total weight of raw materials as 100%, mixing the two and reacting at 70℃ for 3h to obtain pyrazole-5-ol;

[0087] The molecular formula of the 1,3-diketone derivative is shown in the following formula 4):

[0088]

[0089] The molecular formula of the pyrazole-5-ol is shown in the following formula 3):

[0090]

[0091] Then, the methacrylate functionalized pyrazole derivative is prepared, and the preparation method comprises:

[0092] Step 1: mix methacrylic acid and N,N'-dicyclohexyl carbodiimide, control the system temperature to be 35℃, and stand for 1h at the temperature;

[0093] Step 2: under stirring, slowly add the prepared pyrazole-5-ol and mix uniformly;

[0094] Step 3: under stirring, add 4-dimethylaminopyridine, control the system temperature to be 35℃, and keep for 1h at the temperature;

[0095] Step 4: after the reaction is completed, the product is separated and purified by extraction, filtration, etc. to obtain the target product, i.e. the methacrylate functionalized pyrazole derivative, and the molecular formula of the methacrylate functionalized pyrazole derivative is shown in the following formula 2):

[0096] Formula 2):

[0097]

[0098] In formula 2), formula 3) and formula 4), R is -CH(CH3)2;

[0099] The mass ratio of N,N'-dicyclohexyl carbodiimide, 4-dimethylaminopyridine, methacrylic acid and pyrazole-5-ol is 30:5:35:30.

[0100] Preparation of a degradable adhesive with reversible bonding effect:

[0101] The biomass-based isocyanate-based polyurethane prepared above, the silyl-protected phenol prepared above and the methacrylate-functionalized pyrazole derivative prepared above are weighed according to a mass ratio of 30:30:40 respectively and mixed, and then reacted at 80°C for 2h, and then reacted at 120°C for 3h, to obtain the degradable adhesive with reversible bonding effect.

[0102] Example 2

[0103] The present embodiment provides a degradable adhesive with reversible bonding effect, which is prepared by a preparation method comprising the following specific steps:

[0104] Preparation of biomass-based isocyanate-based polyurethane, which is the same as that in Example 1, i.e. comprising:

[0105] Step 1): the bio-based aliphatic isocyanate (a product with a model number of HI-100 produced by Dongguan Delun New Material Co., Ltd.), ethylene glycol and a part of triethylamine catalyst are mixed and reacted at 60°C for 1h;

[0106] Step 2): the modified castor oil (purchased from Guangzhou Chufei Chemical Technology Co., Ltd.) and another part of triethylamine catalyst are added and the reaction is continued at 60°C for 1h;

[0107] Step 3): the product obtained after the reaction in Step 2) is washed and purified to remove possible residual reactants, catalysts and impurities, etc., to obtain the biomass-based isocyanate-based polyurethane;

[0108] The mass ratio of the modified castor oil, the polyol, the bio-based aliphatic isocyanate and the catalyst is 5:20:74.5:0.5.

[0109] Preparation of silyl-protected phenol, which is the same as that in Example 1, i.e. comprising:

[0110] Step (1): imidazole is added to a methanol / ethyl ether mixture (the volume ratio of methanol and ethyl ether is 1:1) and fully dissolved by stirring;

[0111] Step (2): under stirring, tert-butyl dimethyl silyl chloride is slowly added;

[0112] Step (3): under stirring, p-toluenesulfonic acid and N,N'-dimethylformamide were added and ensured to be uniformly mixed;

[0113] Step (4): under stirring, 2,6-bis(hydroxymethyl)-p-cresol was slowly added and mixed uniformly;

[0114] Step (5): after the reaction was completed, the product was purified by extraction, filtration or distillation, etc. to obtain the silyl-protected phenol;

[0115] wherein the mass ratio of 2,6-bis(hydroxymethyl)-p-cresol, N,N'-dimethylformamide, imidazole, tert-butyldimethylsilyl chloride, methanol / ethyl ether mixture and p-toluenesulfonic acid was 4.2:55:3:12:25:0.8, the temperature of the whole preparation process was kept at 35℃, and the time was 2h.

[0116] Preparation of a degradable adhesive with reversible bonding effect:

[0117] According to the mass ratio of 30:30:40, the biomass-based isocyanate-based polyurethane prepared above, the silyl-protected phenol prepared above and the hydrogenated hydroxyl-terminated polyolefin resin (purchased from Dongguan Huayi Plastic Raw Material Co., Ltd.) were weighed and mixed, first reacted at 75℃ for 3h, then heated to 120℃ for 3h, and after the reaction was completed, the degradable adhesive with reversible bonding effect was obtained.

[0118] Example 3

[0119] The present example provides a degradable adhesive with reversible bonding effect, which is prepared by a preparation method comprising the following specific steps:

[0120] Preparation of biomass-based isocyanate-based polyurethane, which is the same as in Example 1, i.e. comprising:

[0121] Step 1): after mixing the bio-based aliphatic isocyanate (product of type HI-100 produced by Dongguan Delun New Material Co., Ltd.), ethylene glycol and part of triethylamine catalyst, it was reacted at 60℃ for 1h;

[0122] Step 2): after adding modified castor oil (purchased from Guangzhou Chufei Chemical Technology Co., Ltd.) and another part of triethylamine catalyst, it was continued to react at 60℃ for 1h;

[0123] Step 3): the product obtained after Step 2) was washed and purified to remove possible residual reactants, catalysts and impurities, etc. to obtain the biomass-based isocyanate-based polyurethane;

[0124] The mass ratio of the modified castor oil, the polyol, the bio-based aliphatic isocyanate, and the catalyst is 5:20:74.5:0.5.

[0125] The preparation of the methacrylate functionalized pyrazole derivative is the same as in Example 1, i.e. comprising:

[0126] The pyrazole-5-ol is first prepared by a method comprising: taking 45% of the 1,3-diketone derivative and 55% of the monohydrizine based on the total weight of the raw materials as 100% and mixing them to react at 70°C for 3h to obtain the pyrazole-5-ol;

[0127] The 1,3-diketone derivative has the following formula 4):

[0128]

[0129] The pyrazole-5-ol has the following formula 3):

[0130]

[0131] The methacrylate functionalized pyrazole derivative is then prepared by a method comprising:

[0132] Step 1: The methacrylic acid and N,N'-dicyclohexyl carbodiimide are mixed and the system temperature is controlled at 35°C, and the system is kept at this temperature for 1h;

[0133] Step 2: The pyrazole-5-ol prepared above is slowly added under stirring and mixed uniformly;

[0134] Step 3: 4-dimethylaminopyridine is added under stirring and the system temperature is controlled at 35°C, and the system is kept at this temperature for 1h;

[0135] Step 4: After the reaction is completed, the product is separated and purified by extraction, filtration, etc. to obtain the target product, i.e. the methacrylate functionalized pyrazole derivative, which has the following formula

[0136] as shown in formula 2):

[0137]

[0138] In formulae 2), 3) and 4), R is -CH(CH3)2.

[0139] The mass ratio of the N,N'-dicyclohexyl carbodiimide, the 4-dimethylaminopyridine, the methacrylic acid, and the pyrazole-5-ol is 30:5:35:30.

[0140] Preparation of a degradable adhesive with reversible adhesion effect:

[0141] The biomass-based isocyanate-based polyurethane prepared above, the methacrylate functionalized pyrazole derivative prepared above and hydrogenated hydroxyl-terminated polyolefin resin (purchased from Dongguan Huayi Plastic Raw Material Co., Ltd.) were weighed according to a mass ratio of 20:40:40 respectively and mixed, and then reacted at 75°C for 3h, and then reacted at 120°C for 3h, to obtain the degradable adhesive with reversible adhesion effect.

[0142] Example 4

[0143] The present embodiment provides a degradable adhesive with reversible adhesion effect, which is prepared by a preparation method comprising the following specific steps:

[0144] The preparation of biomass-based isocyanate-based polyurethane is the same as that in Example 1, that is, comprising:

[0145] Step 1): the bio-based aliphatic isocyanate (product of type HI-100 produced by Dongguan Delun New Material Co., Ltd.), ethylene glycol and part of the triethylamine catalyst were mixed and reacted at 60°C for 1h;

[0146] Step 2): after adding modified castor oil (purchased from Guangzhou Chufei Chemical Technology Co., Ltd.) and another part of the triethylamine catalyst, the reaction was continued at 60°C for 1h;

[0147] Step 3): the product obtained after step 2) was washed and purified to remove possible residual reactants, catalysts and impurities, etc., to obtain the biomass-based isocyanate-based polyurethane;

[0148] Among them, the mass ratio of modified castor oil, polyol, bio-based aliphatic isocyanate and catalyst is 5:20:74.5:0.5.

[0149] The preparation of silyl-protected phenol is the same as that in Example 1, that is, comprising:

[0150] Step (1): imidazole was added to a methanol / ethyl ether mixture (volume ratio of methanol to ethyl ether was 1:1) and fully dissolved by stirring;

[0151] Step (2): under stirring, tert-butyl dimethyl silyl chloride was slowly added;

[0152] Step (3): under stirring, p-toluenesulfonic acid and N,N'-dimethylformamide were added and uniformly mixed;

[0153] Step (4): under stirring, 2,6-bis(hydroxymethyl)-p-cresol was slowly added and uniformly mixed;

[0154] Step (5): After the reaction is completed, the product is purified using extraction, filtration, or distillation, etc. to obtain the silyl-protected phenol;

[0155] wherein the mass ratio of 2,6-bis(hydroxymethyl)-p-cresol, N,N'-dimethylformamide, imidazole, tert-butyldimethylsilyl chloride, methanol / ethyl ether mixture, and p-toluenesulfonic acid is 4.2:55:3:12:25:0.8, the temperature of the entire preparation process is maintained at 35°C, and the time is 2h.

[0156] The preparation of the methacrylate-functionalized pyrazole derivative is the same as in Example 1, i.e. it comprises:

[0157] The pyrazole-5-ol is first prepared by the following method: 45% of the 1,3-diketone derivative and 55% of the monohydrate hydrazine are weighed based on the total weight of the raw materials being 100% and mixed, and then reacted at 70°C for 3h to obtain the pyrazole-5-ol;

[0158] wherein the 1,3-diketone derivative has the following formula 4):

[0159]

[0160] The pyrazole-5-ol has the following formula 3):

[0161]

[0162] The methacrylate-functionalized pyrazole derivative is then prepared by the following method:

[0163] Step 1: The methacrylic acid and N,N'-dicyclohexyl carbodiimide are mixed, and the temperature of the system is controlled at 35°C, and then the system is kept at this temperature for 1h;

[0164] Step 2: The pyrazole-5-ol prepared above is slowly added under stirring, and then mixed uniformly;

[0165] Step 3: 4-dimethylaminopyridine is added under stirring, and the temperature of the system is controlled at 35°C, and then the system is kept at this temperature for 1h;

[0166] Step 4: After the reaction is completed, the product is separated and purified by extraction, filtration, etc. to obtain the target product, i.e. the methacrylate-functionalized pyrazole derivative, which has the following formula

[0167] as shown in formula 2):

[0168]

[0169] In formula 2), formula 3), and formula 4), R is -CH(CH3)2.

[0170] wherein the mass ratio of N,N'-dicyclohexyl carbodiimide, 4-dimethylaminopyridine, methacrylic acid and pyrazole-5-ol is 30:5:35:30.

[0171] Preparation of degradable adhesive with reversible adhesion effect:

[0172] The biomass-based isocyanate-based polyurethane prepared above, the silyl-protected phenol prepared above, hydrogenated hydroxyl-terminated polyolefin resin (purchased from Dongguan Huayi Plastic Raw Material Co., Ltd.) and the methacrylate-functionalized pyrazole derivative prepared above were weighed according to a mass ratio of 25:25:25:25 respectively and mixed, first reacted at 80°C for 2h, then reacted at 120°C for 3h, and the degradable adhesive with reversible adhesion effect was obtained after the reaction was completed.

[0173] Comparative Example 1

[0174] The present comparative example provides a kind of adhesive, which is prepared by the preparation method comprising the following specific steps:

[0175] The epoxy resin and polyamide curing agent were weighed according to 70% and 30% respectively based on the total weight of raw materials as 100%, and then mixed, after mixing, first reacted at 100°C for 3h, then reacted at 120°C for 2h, and the adhesive was prepared after the reaction was completed.

[0176] Comparative Example 2

[0177] The present comparative example provides a kind of adhesive, which is prepared by the preparation method comprising the following specific steps:

[0178] The biomass-based isocyanate-based polyurethane and silyl-protected phenol were prepared according to the same preparation method as Example 1, the biomass-based isocyanate-based polyurethane and silyl-protected phenol prepared above were weighed according to a mass ratio of 50:50 respectively and mixed, first reacted at 80°C for 2h, then reacted at 120°C for 3h, and the adhesive was obtained after the reaction was completed.

[0179] Comparative Example 3

[0180] The present comparative example provides a kind of adhesive, which is prepared by the preparation method comprising the following specific steps:

[0181] The biomass-based isocyanate-based polyurethane was prepared according to the same preparation method as Example 1, the biomass-based isocyanate-based polyurethane prepared above and hydrogenated hydroxyl-terminated polyolefin resin (purchased from Dongguan Huayi Plastic Raw Material Co., Ltd.) were weighed according to a mass ratio of 50:50 respectively and mixed, first reacted at 80°C for 2h, then reacted at 120°C for 3h, and the adhesive was obtained after the reaction was completed.

[0182] Comparative Example 4

[0183] The present comparative example provides an adhesive which is prepared by a preparation method comprising the following specific steps:

[0184] The biomass-based isocyanate-based polyurethane and the methacrylate functionalized pyrazole derivative are prepared according to the same preparation method as in Example 1, respectively, and the biomass-based isocyanate-based polyurethane and the methacrylate functionalized pyrazole derivative prepared above are weighed according to a mass ratio of 50:50 and mixed, and then reacted at 80°C for 2h, and then reacted at 120°C for 3h, and then the adhesive is obtained after the reaction is completed.

[0185] Comparative Example 5

[0186] The present comparative example provides an adhesive which is prepared by a preparation method comprising the following specific steps:

[0187] The silyl-protected phenol is prepared according to the same preparation method as in Example 1, and the silyl-protected phenol prepared above and the hydrogenated hydroxyl-terminated polyolefin resin purchased from Dongguan Huayi Plastic Raw Material Co., Ltd. are weighed according to a mass ratio of 50:50 and mixed, and then reacted at 80°C for 2h, and then reacted at 120°C for 3h, and then the adhesive is obtained after the reaction is completed.

[0188] Comparative Example 6

[0189] The present comparative example provides an adhesive which is prepared by a preparation method comprising the following specific steps:

[0190] The silyl-protected phenol and the methacrylate functionalized pyrazole derivative are prepared according to the same preparation method as in Example 1, respectively, and the silyl-protected phenol and the methacrylate functionalized pyrazole derivative prepared above are weighed according to a mass ratio of 50:50 and mixed, and then reacted at 80°C for 2h, and then reacted at 120°C for 3h, and then the adhesive is obtained after the reaction is completed.

[0191] Comparative Example 7

[0192] The present comparative example provides an adhesive which is prepared by a preparation method comprising the following specific steps:

[0193] The methacrylate functionalized pyrazole derivative is prepared according to the same preparation method as in Example 1, and the methacrylate functionalized pyrazole derivative prepared above and the hydrogenated hydroxyl-terminated polyolefin resin purchased from Dongguan Huayi Plastic Raw Material Co., Ltd. are weighed according to a mass ratio of 50:50 and mixed, and then reacted at 80°C for 2h, and then reacted at 120°C for 3h, and then the adhesive is obtained after the reaction is completed.

[0194] Evaluation Example 1

[0195] In this evaluation example, the degradation performance and the bonding strength of the degradable adhesive with reversible adhesion effect provided by Example 1-Example 4 and the adhesive provided by Comparative Example 1-Comparative Example 7 were evaluated respectively:

[0196] The degradation performance evaluation method comprises: first adding 400 mL of a degradation solution into a polytetrafluoroethylene tank, then adding 30 g of the degradable adhesive with reversible adhesion effect or the adhesive into the polytetrafluoroethylene tank, and finally testing the time required for complete dissolution of the degradable adhesive and the adhesive under different simulated temperature conditions.

[0197] The degradation solution comprises 70 wt% of tetrabutylammonium fluoride and 30 wt% of a sodium hydroxide aqueous solution (mass concentration of 15%) based on the total weight of the degradation solution as 100%.

[0198] The bonding strength evaluation method comprises: first testing the bonding strength of the degradable adhesive and the adhesive based on GB T 7124-2008, then breaking the material after the test and retesting the bonding strength after healing at the corresponding test temperature.

[0199] The degradation performance and the bonding strength results obtained under different simulated temperature conditions in this evaluation example are shown in Tables 1-4 respectively.

[0200] Table 1 Comparison results of the degradation performance and the bonding strength of the degradable adhesive with reversible adhesion effect provided by Example 1-Example 4 and the adhesive provided by Comparative Example 1-Comparative Example 7 (100℃)

[0201] Formulation Adhesive strength / MPa Degradation time / h Adhesive strength after 5 break healings / MPa Example 1 3.1 15 2.2 Example 2 2.6 21 1.4 Example 3 3.5 31 2.8 Example 4 3.7 14 3.1 Comparative Example 1 1.3 No degradation No healing Comparative Example 2 1.1 12 No healing Comparative Example 3 1.4 No degradation No healing Comparative Example 4 1.2 No degradation No healing Comparative Example 5 0.8 16 No healing Comparative Example 6 0.9 17 No healing Comparative Example 7 1.2 No degradation No healing

[0202] Table 2 Comparison results of the degradation performance and the bonding strength of the degradable adhesive with reversible adhesion effect provided by Example 1-Example 4 and the adhesive provided by Comparative Example 1-Comparative Example 7 (120℃)

[0203] Formulation Adhesive strength / MPa Degradation time / h Adhesive strength after 5 break healings / MPa Example 1 3.0 15 2.0 Example 2 2.1 19 1.1 Example 3 3.4 27 2.7 Example 4 3.5 12 2.9 Comparative Example 1 1.1 No degradation No healing Comparative Example 2 1.0 10 No healing Comparative Example 3 1.1 No degradation No healing Comparative Example 4 1.1 No degradation No healing Comparative Example 5 0.7 15 No healing Comparative Example 6 0.5 14 No healing Comparative Example 7 0.8 No degradation No healing

[0204] Table 3 Comparison results of the degradation performance and the bonding strength of the degradable adhesive with reversible adhesion effect provided by Example 1-Example 4 and the adhesive provided by Comparative Example 1-Comparative Example 7 (140℃)

[0205] Formulation Adhesive strength / MPa Degradation time / h Adhesive strength after 5 break healings / MPa Example 1 2.8 14 1.9 Example 2 1.8 18 0.8 Example 3 3.4 23 2.3 Example 4 3.3 10 2.5 Comparative Example 1 1.0 No degradation No healing Comparative Example 2 0.8 9 No healing Comparative Example 3 0.8 No degradation No healing Comparative Example 4 0.7 No degradation No healing Comparative Example 5 0.5 14 No healing Comparative Example 6 0.3 11 No healing Comparative Example 7 0.7 No degradation No healing

[0206] Table 4 Comparison results of the degradation performance and the bonding strength of the degradable adhesive with reversible adhesion effect provided by Example 1-Example 4 and the adhesive provided by Comparative Example 1-Comparative Example 7 (160℃)

[0207] Formulation Adhesive strength / MPa Degradation time / h Adhesive strength after 5 break healings / MPa Example 1 2.2 12 1.4 Example 2 1.4 17 0.6 Example 3 3.1 21 2.1 Example 4 3.0 8 2.4 Comparative Example 1 0.9 No degradation No healing Comparative Example 2 0.7 7 No healing Comparative Example 3 0.5 No degradation No healing Comparative Example 4 0.6 No degradation No healing Comparative Example 5 0.3 12 No healing Comparative Example 6 0.2 11 No healing Comparative Example 7 0.5 No degradation No healing

[0208] As can be seen from the above Tables 1-4, compared with the adhesives provided by Comparative Examples 1-7, the degradable adhesives with reversible adhesion effect provided by Example 1-4 have better bonding strength under different temperature conditions, can realize repeated high-strength bonding with the wellbore metal wall surface, and also have better degradation effect, can fully react with the plug removal fluid under the formation temperature condition, and achieve the purpose of removing the wellbore plug.

[0209] In Comparative Examples 2-7, two of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin, methacrylate functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane are used as raw materials to prepare adhesives. As can be seen from Tables 1-4, compared with the adhesives provided by Example 1-4, the adhesives prepared in the comparative examples have lower bonding strength, indicating that they cannot achieve reversible adhesion effect, which shows that the adhesives prepared by using any three or four of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin, methacrylate functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane as raw materials can have reversible adhesion effect, and the adhesives prepared by two-by-two combination as raw materials cannot achieve the above effect.

[0210] As can be seen from the degradation time data of the degradable adhesives provided by Example 1-4 in the above Tables 1-4, when the raw materials for preparing the degradable adhesives contain silyl-protected phenol, the degradation time of the prepared degradable adhesives is shorter, which further verifies that the silyl-protected phenol containing fluoride-responsive degradation functional groups can make the degradable adhesive respond to specific stimuli for degradation. When the degradable adhesive is exposed to an environment containing fluoride, these functional groups (mainly -Si-O- bonds) will be degraded by temperature stimulation (reaction temperature), thereby causing the decomposition and dissolution of the degradable adhesive.

[0211] The above is only a specific embodiment of the present application, which cannot limit the scope of the application. Therefore, the replacement of equivalent components or equivalent changes and modifications made within the scope of the patent protection of the present application should still fall within the scope of the present patent. In addition, the technical features in the present application can be freely combined with each other, and the technical features can be freely combined with each other.

Claims

1. A degradable adhesive having a reversible adhesion effect, characterized in that, The degradable adhesive with reversible adhesion effect is prepared by reaction of raw materials, wherein the raw materials include any three or four of silyl-protected phenol, hydrogenated hydroxyl-terminated polyolefin resin, methacrylate functionalized pyrazole derivative and biomass-based isocyanate-based polyurethane, and the silyl-protected phenol contains fluoride-responsive degradation functional groups; The mass ratio of the silyl-protected phenol, the hydrogenated hydroxyl-terminated polyolefin resin, the methacrylate functionalized pyrazole derivative and the biomass-based isocyanate-based polyurethane is 25-90:10-80:25-75:20-70.

2. The degradable adhesive of claim 1, wherein, The biomass-based isocyanate-based polyurethane is prepared by reaction of modified castor oil, polyol and bio-based aliphatic isocyanate under catalysis of a catalyst; The mass ratio of the modified castor oil, the polyol, the bio-based aliphatic isocyanate and the catalyst is 5-25:20-40:70-85:0.1-0.

8.

3. The degradable adhesive of claim 2, wherein, In the preparation process of the biomass-based isocyanate-based polyurethane, the reaction temperature is 45-60℃ and the reaction time is 1-4h.

4. The degradable adhesive according to any one of claims 1 to 3, wherein, The biomass-based isocyanate-based polyurethane is prepared by the preparation method comprising the following specific steps: Step 1): mixing the bio-based aliphatic isocyanate, the polyol and a part of the catalyst and then reacting at 45-60℃ for 1-2h; Step 2): adding the modified castor oil and another part of the catalyst and then continuing to react at 45-60℃ for 1-2h to obtain the biomass-based isocyanate-based polyurethane.

5. The degradable adhesive of claim 1, wherein, The structure of the silyl-protected phenol is shown in the following formula 1):

6. The degradable adhesive according to claim 1 or 5, wherein The silyl-protected phenol is obtained by reaction of 2,6-bis(hydroxymethyl)-p-cresol and tert-butyldimethylsilyl chloride; The mass ratio of the 2,6-bis(hydroxymethyl)-p-cresol and the tert-butyldimethylsilyl chloride is 1-7:6-13, and the reaction temperature is 35-55℃ and the reaction time is 1-3h.

7. The degradable adhesive of claim 1, wherein, The molecular formula of the methacrylate functionalized pyrazole derivative is shown in the following formula 2): In formula 2), R is -CH3, -CH(CH3)2 or -C(CH3)2.

8. The degradable adhesive according to claim 1 or 7, wherein, The methacrylate functionalized pyrazole derivative is prepared by esterification reaction of methacrylic acid and pyrazole-5-ol; The molecular formula of the pyrazole-5-ol is shown in the following formula 3): In formula 3), R is -CH3, -CH(CH3)2 or -C(CH3)2; The mass ratio of the methacrylic acid and the pyrazole-5-ol is 25-35:30-45, the reaction temperature is 20-35℃ and the reaction time is 0.5-4h.

9. The degradable adhesive of claim 8, wherein, The pyrazole-5-ol is prepared by reaction of a 1,3-diketone derivative and monohydric hydrazine at 65-80℃ for 3-5h in a mass ratio of 45-50:55-60; The molecular formula of the 1,3-diketone derivative is shown in the following formula 4): In formula 4), R is -CH3, -CH(CH3)2 or -C(CH3)2.

10. The degradable adhesive of claim 1, wherein, In the preparation process of the degradable adhesive with reversible adhesion effect, the reaction is first carried out at 75-85℃ for 2-3h, and then the temperature is raised to 110-125℃ for 1-3h.

11. Process for the preparation of degradable adhesives with reversible adhesive effect according to any one of claims 1 to 10, characterized in that, The preparation method comprises: Any three or four of the silyl-protected phenol, the hydrogenated hydroxyl-terminated polyolefin resin, the methacrylate-functionalized pyrazole derivative and the biomass-based isocyanate-based polyurethane are taken by the amount ratio, mixed and then reacted, and the degradable adhesive with reversible adhesion effect is prepared after the reaction is completed.

12. The use of the degradable adhesive with reversible adhesion effect according to any one of claims 1-10 in the staged fracturing temporary plugging operation of complex casing variable well or the plugging operation of severe leakage well.

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