A retarder, its preparation method and application

Abstract

This invention provides a retarder, its preparation method, and its application. One aspect of this invention provides a method for preparing the retarder, comprising the following steps: modifying nano-zinc oxide with vinyltrimethoxysilane to obtain modified nano-zinc oxide; mixing 2-methyl-2-acrylamidopropanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, and dimethyldiallyl ammonium chloride to obtain a monomer solution; mixing the modified nano-zinc oxide and the monomer solution, and carrying out a polymerization reaction in the presence of an initiator; after the polymerization reaction is completed, the retarder is obtained. The retarder prepared by the method provided by this invention can withstand temperatures up to 240℃, and when the addition amount is 0.5%-5%, the thickening time of the cement slurry at 240℃ is 280-528 min, and the compressive strength of the cement stone after 24 hours of curing can reach above 27.3 MPa, which can meet the requirements of ultra-high temperature cementing.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of retarder, in particular to a retarder, a preparation method and application thereof. BACKGROUND

[0002] With the progress of drilling technology and the deepening of oil field exploration and development, the deep well and ultra-deep well with bottom hole temperature exceeding 200℃ gradually increase, the complex well conditions of deep well and ultra-deep well bring new challenges to cementing technology, and at the same time, higher performance requirements are put forward for the performance of cementing fluid, i.e. cement slurry. As one of the main additives of cement slurry, the retarder has the effect of controlling the thickening time of cement slurry, so as to ensure the pumpability of cement slurry within a specified time, and at the same time, does not affect the comprehensive performance of cement stone, and ensures the safe operation of cementing construction.

[0003] At present, the retarder mainly includes lignin sulfonate and its derivatives, hydroxyl carboxylic acid and its salt, cellulose and its derivatives, sugar and its derivatives, organic phosphate and inorganic salt, etc., but all have the shortcomings of unstable performance at high temperature, sensitive to temperature and affecting the development strength of cement stone. The polymer retarder has the characteristics of structure design, and through polymerization reaction, monomers containing various functional groups are polymerized together, so that the retarder has better performance.

[0004] The patent for invention with publication number CN11253519A provides an anti-high-temperature oil well cement retarder, which is obtained by polymerization of 2-methyl-2-acrylamidopropanesulfonic acid, itaconic acid, acrylic acid, N,N-dimethylaminopropyl acrylamide and N-vinylpyrrolidone, and the temperature resistance of the retarder can only reach 180℃; the patent for invention with publication number CN105131918A provides a 200℃-resistant oil well cement retarder, which is obtained by copolymerization of enesulfonic acid monomer, maleic anhydride and ene monomer with a hydrophilic group long chain, and the temperature resistance of the retarder can reach 200℃, and the thickening time of the retarder at 200℃ is 240min-360min; Yu Yongjin et al. prepared a five-membered copolymer containing sulfonic acid groups, double carboxyl groups, chain rigid groups and cationic groups in the main chain through aqueous solution free radical polymerization, and the maximum applicable temperature of the retarder can reach 210℃, and when the retarder addition amount is 8.5%, the cement slurry thickening time is 382min (Yu Yongjin, Ding Zhiwei, Zhang Li, Zhang Hua, Guo Jintang. Anti-circulating temperature 210℃ ultra-high temperature cementing cement slurry [J]. Drilling fluid and completion fluid, 2019, 36(03): 349-354.); the patent for invention with publication number CN104403056A provides a preparation method of a high-temperature resistant copolymer oil well cement slurry retarder, and the retarder prepared according to the method can resist 230℃, but when the retarder addition amount is 6%, the thickening time at 230℃ can only reach 289min; the patent for invention with publication number CN111825788A provides a high-temperature retarder for cementing, which is obtained by polymerization and hydrolysis of non-ionic amide monomer, anionic sulfonic acid monomer and functional monomer, and the maximum temperature resistance of the retarder can reach 240℃, but when the retarder addition amount is 8%, the thickening time can only reach 267min. Therefore, how to provide a retarder with high temperature resistance, low dosage, long thickening time and cement stone compressive strength meeting the requirements of ultra-high temperature cementing has attracted more and more attention. SUMMARY

[0005] The present application provides a retarder, a preparation method and application thereof, the retarder can resist 240℃, and when the addition amount is 0.5%-5%, the thickening time of the cement slurry at 240℃ is 280-528min, the cement stone compressive strength after the cement slurry system is cured for 24h reaches 27.3MPa or more, and the requirements of ultra-high temperature cementing can be met.

[0006] The present application provides a retarder, a preparation method and application thereof, the retarder can resist 240℃, and when the addition amount is 0.5%-5%, the thickening time of the cement slurry at 240℃ is 280-528min, the cement stone compressive strength after the cement slurry system is cured for 24h reaches 27.3MPa or more, and the requirements of ultra-high temperature cementing can be met.

[0007] The modified nano zinc oxide is obtained by modifying nano zinc oxide with vinyl trimethoxysilane;

[0008] The monomer solution is obtained by mixing 2-methyl-2-acrylamidopropanesulfonic acid, sodium allylsulfonate, maleic acid, p-hydroxy cinnamic acid and dimethyl diallyl ammonium chloride;

[0009] Mixing the modified nano-zinc oxide and monomer solution, and performing polymerization reaction in the presence of initiator, and obtaining the retarder after the polymerization reaction.

[0010] In one embodiment, the nano-zinc oxide is modified by using vinyl trimethoxysilane, and the modification process specifically comprises the following steps:

[0011] The nano-zinc oxide and vinyl trimethoxysilane are dissolved in a solvent, and treated at 40-60℃ for 10-24 hours, and then the solid particles are collected, washed, dried, and crushed to obtain the modified nano-zinc oxide.

[0012] In one embodiment, the mass ratio of 2-methyl-2-propenoylamino propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, dimethyl diallyl ammonium chloride and modified nano-zinc oxide is (60-85):(15-25):(10-16):(8-15):(12-25):(10-15).

[0013] In one embodiment, the initiator is one or both of ammonium persulfate and potassium persulfate.

[0014] In one embodiment, the mass of the initiator is 2%-5% of the total mass of 2-methyl-2-propenoylamino propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, and dimethyl diallyl ammonium chloride.

[0015] In one embodiment, the temperature of the polymerization reaction is 60-80℃, and the reaction time is 4-6 hours.

[0016] The second aspect of the present application provides a retarder prepared according to any of the above-mentioned methods.

[0017] The third aspect of the present application provides a cement paste comprising the above-mentioned retarder.

[0018] In one embodiment, the mass of the retarder is 0.5%-5% of the total mass of the cement paste.

[0019] In one embodiment, the thickening time of the cement paste at 240℃ is 280-528min, and the compressive strength of the cement paste after 24h curing is greater than or equal to 27.3MPa.

[0020] The application provides a preparation method of a retarder, which is obtained by polymerization of modified nano-zinc oxide after modification of 2-methyl-2-propenoylamino propanesulfonic acid, sodium allylsulfonate, maleic acid, p-hydroxycinnamic acid, dimethyldiallyl ammonium chloride and vinyltrimethoxysilane, the retarder can resist 240 DEG C, and when the adding amount is 0.5%-5%, the thickening time of the cement paste at 240 DEG C is 280-528 min, the compressive strength of the cement stone after curing for 24 h is above 27.3 MPa, and the requirements of super-high-temperature well cementation can be met. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, below the drawings needed to be used in the embodiments or the prior art description will be briefly introduced, obviously, the drawings in the following description are some embodiments of the present application, and for the ordinary skilled in the art, other drawings can be obtained without creative labor.

[0022] Figure 1 The preparation method of the retarder provided by an embodiment of the present application is shown in the flowchart. DETAILED DESCRIPTION

[0023] In order to make the purpose, technical solutions and advantages of the present application more clear, below the technical solutions in the embodiments of the present application will be clearly and completely described with the embodiments of the present application, obviously, the described embodiments are some embodiments of the present application, but not all the embodiments. Based on the embodiments in the present application, all the other embodiments obtained by the ordinary skilled in the art without creative labor are within the protection scope of the present application.

[0024] The first aspect of the present application provides a preparation method of a retarder, comprising the following steps:

[0025] The nano-zinc oxide is modified by using vinyltrimethoxysilane to obtain modified nano-zinc oxide;

[0026] 2-methyl-2-propenoylamino propanesulfonic acid, sodium allylsulfonate, maleic acid, p-hydroxycinnamic acid and dimethyldiallyl ammonium chloride are mixed to obtain a monomer solution;

[0027] The modified nano-zinc oxide and the monomer solution are mixed, and the polymerization reaction is carried out under the condition of an initiator, and the retarder is obtained after the reaction is finished.

[0028] The application provides a preparation method of a retarder, which is obtained by polymerization reaction of 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allylsulfonate, maleic acid, p-hydroxycinnamic acid, dimethyl diallyl ammonium chloride and modified nano zinc oxide as polymerization monomers, wherein the modified nano zinc oxide is obtained by modification of vinyl trimethoxysilane. The retarder prepared by the preparation method has high high-temperature resistance, can form a film with low solubility and low permeability on the surface of cement particles, hinders further contact of water and cement clinker minerals, inhibits cement hydration, prolongs cement thickening time, and does not affect the compressive strength of the cement slurry after solidification. Specifically, the retarder prepared by the preparation method can withstand a temperature of 240 DEG C, and when the addition amount is 0.5%-5%, the thickening time of the cement slurry at 240 DEG C is 280-528 min, and the compressive strength of the cement stone after 24 h curing is higher than 27.3 MPa, which can meet the requirements of super-high-temperature well cementing.

[0029] Figure 1 The preparation method of the retarder provided by an embodiment of the application is shown in a flowchart as shown in Figure 1 The method comprises the following steps:

[0030] In step 100, nano zinc oxide is modified by using vinyl trimethoxysilane to obtain modified nano zinc oxide.

[0031] The vinyl trimethoxysilane is a coupling agent, the silicon-oxygen end of which can be condensed with the hydroxyl group on the surface of the nano zinc oxide, and the other end of the vinyl double bond can be copolymerized with 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allylsulfonate, maleic acid, p-hydroxycinnamic acid and dimethyl diallyl ammonium chloride, so that the nano zinc oxide is connected to the polymerization chain. If the vinyl trimethoxysilane, the nano zinc oxide and the above-mentioned five polymerization monomers are directly mixed, the coupling reaction and the polymerization reaction cannot be completed at the same time, the nano zinc oxide cannot be fully involved in the polymerization reaction, the polymerization reaction cannot be controlled, the molecular structure of the obtained retarder has randomness, and the retarding effect of the final retarder is affected. The vinyl trimethoxysilane is selected as the silane coupling agent because, compared with other silane coupling agents, the vinyl trimethoxysilane has suitable steric hindrance, which is conducive to the generation of zinc hydroxide precipitate on the surface of the cement particles, and then a film with low solubility and low permeability is formed to hinder further contact of water and cement clinker minerals.

[0032] The specific modification process includes: dissolving nano zinc oxide and vinyl trimethoxysilane in a solvent and ultrasonic treatment, so that they are fully dispersed in the solvent, and the solvent can include isopropyl alcohol and water; then heated by water bath, the temperature is controlled at 40-60℃, and treated for 10-24 hours, after the treatment is completed, the solid particles are collected, and the solid particles are sequentially washed, dried and crushed to obtain modified nano zinc oxide.

[0033] Further, on the basis of obtaining modified nano zinc oxide with equivalent performance, controlling the temperature at 50℃ can effectively shorten the treatment time, specifically 10 hours, after the treatment is completed, the solid particles can be collected according to the conventional technical means in the art, for example, centrifugation, and the solid particles are sequentially washed, dried and crushed, the washing can use the solvent isopropyl alcohol, the drying can be carried out in an oven, and the crushing means that the agglomerated modified nano zinc oxide is dispersed by physical means, which is helpful for subsequent mixing with the monomer solution.

[0034] Step 200, mixing 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxy cinnamic acid and dimethyl diallyl ammonium chloride to obtain a monomer solution;

[0035] In the specific mixing process, 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxy cinnamic acid and dimethyl diallyl ammonium chloride are dissolved in deionized water to obtain a monomer solution, and the mass of deionized water is 230%-400% of the total mass of 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxy cinnamic acid and dimethyl diallyl ammonium chloride.

[0036] Step 300, mixing the modified nano zinc oxide and the monomer solution, and performing a polymerization reaction under the condition of an initiator, and obtaining the retarder after the reaction is completed.

[0037] In order to facilitate the subsequent polymerization reaction, the monomer solution prepared in step 200 is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant-pressure burette and a nitrogen inlet, and is fully stirred under the protection of nitrogen, and at the same time, the temperature of the monomer solution is increased to 60-80℃, which can be specifically achieved by water bath heating, which is helpful to improve the conversion rate of the subsequent polymerization reaction.

[0038] Subsequently, the modified nano zinc oxide can be added to the monomer solution, in order to further improve the performance of the retarder, the mass ratio of 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxy cinnamic acid, dimethyl diallyl ammonium chloride and modified nano zinc oxide is (60-85):(15-25):(10-16):(8-15):(12-25):(10-15).

[0039] In the specific mixing process, since the nano zinc oxide is an amphoteric oxide, over-acid or over-base is easy to cause the reaction of the modified nano zinc oxide, therefore, before the modified nano zinc oxide is added, the pH of the monomer solution needs to be adjusted to neutral, and the adjusting process can be realized by dropwise adding a 30wt% NaOH solution.

[0040] After the modified nano zinc oxide and the monomer solution are mixed, sufficient stirring is performed, the stirring speed can be 300r / min, and the stirring time is 20-40min, so that the two are fully mixed.

[0041] Subsequently, the initiator can be added dropwise into the reaction system, the initiator is one or both of ammonium persulfate and potassium persulfate, and the mass of the initiator is 2%-5% of the total mass of 2-methyl-2-propenoyl amido propanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid and dimethyl diallyl ammonium chloride, specifically, the initiator can be configured into a 30wt% initiator aqueous solution, and then gradually added dropwise into the mixed system of the monomer solution and the modified nano zinc oxide, to initiate the polymerization reaction, after the reaction is performed for 4-6 hours, the polymerization reaction is completed, and the reaction product is collected to obtain the retarder.

[0042] The retarder prepared by the preparation method is added into the cement slurry, used for relieving the hydration speed of the cement slurry, prolonging the setting time, and ensuring the safe performance of the cementing construction, the cement slurry is not limited, and can be the cementing cement slurry commonly used in the field, through the performance test on the cement slurry added with the retarder, the retarder prepared by the preparation method provided by the present application can withstand 240℃, and when the addition amount is 0.5%-5%, the thickening time of the cement slurry at 240℃ is 280-528min, the compressive strength of the cement stone after curing for 24h can reach more than 27.3MPa, and the requirement of the ultra-high temperature cementing can be met.

[0043] The present application is specifically described below in combination with examples:

[0044] Example 1

[0045] The preparation method of the retarder provided in the present embodiment includes the following steps:

[0046] Step 1, weigh 15g of nano zinc oxide, 30g of vinyl trimethoxysilane, 600g of isopropyl alcohol and 150g of water, and mix them uniformly, ultrasonic treatment for 0.5 hours by using an ultrasonic nanomaterial dispersing instrument, backflow treatment for 10 hours by using a 50℃ water bath, centrifugal separation to obtain a solid, washing with isopropyl alcohol and then placing in an oven for heating at 85℃ for 24 hours, crushing and grinding to obtain the modified nano zinc oxide;

[0047] Step 2, 70g 2-methyl-2-propenoylamino propanesulfonic acid, 15g sodium allyl sulfonate, 15g maleic acid, 10g p-hydroxy cinnamic acid, 12g dimethyl diallyl ammonium chloride are dissolved in 488g deionized water to obtain a monomer solution;

[0048] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 60℃ in a water bath, a 30% sodium hydroxide solution is added dropwise to adjust the pH of the above solution to 7, 12g modified nano zinc oxide is added, and stirred at 300r / min for 30min, then 11.2g 30% ammonium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 5h, and cooled to room temperature to obtain a retarder.

[0049] Example 2

[0050] The preparation method of the retarder provided in this embodiment comprises the following steps:

[0051] Step 1, refer to example 1;

[0052] Step 2, 60g 2-methyl-2-propenoylamino propanesulfonic acid, 20g sodium allyl sulfonate, 16g maleic acid, 8g p-hydroxy cinnamic acid, 15g dimethyl diallyl ammonium chloride are dissolved in 357g deionized water to obtain a monomer solution;

[0053] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 80℃ in a water bath, a 30% sodium hydroxide solution is added dropwise to adjust the pH of the above solution to 7, 10g modified nano zinc oxide is added, and stirred at 300r / min for 20min, then 9.0g 30% potassium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 4h, and cooled to room temperature to obtain a retarder.

[0054] Example 3

[0055] The preparation method of the retarder provided in this embodiment comprises the following steps:

[0056] Step 1, refer to example 1;

[0057] Step 2, 80g 2-methyl-2-propenoylamino propanesulfonic acid, 25g sodium allyl sulfonate, 14g maleic acid, 10g p-hydroxy cinnamic acid, 20g dimethyl diallyl ammonium chloride are dissolved in 447g deionized water to obtain a monomer solution;

[0058] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 65℃ in a water bath, then 15g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 35min, then 19.1g of a 30wt% potassium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 6h, and then cooled to room temperature to obtain the retarder.

[0059] Example 4

[0060] The preparation method of the retarder provided in the embodiment comprises the following steps:

[0061] Step 1, refer to Example 1;

[0062] Step 2, 85g of 2-methyl-2-propenoylamino propanesulfonic acid, 18g of sodium allyl sulfonate, 15g of maleic acid, 12g of p-hydroxy cinnamic acid and 25g of dimethyl diallyl ammonium chloride are dissolved in 387.5g of deionized water to obtain a monomer solution;

[0063] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 70℃ in a water bath, then 13.5g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 40min, then 12.7g of a 30wt% ammonium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 6h, and then cooled to room temperature to obtain the retarder.

[0064] Example 5

[0065] The preparation method of the retarder provided in the embodiment comprises the following steps:

[0066] Step 1, refer to Example 1;

[0067] Step 2, 65g of 2-methyl-2-propenoylamino propanesulfonic acid, 18g of sodium allyl sulfonate, 16g of maleic acid, 14g of p-hydroxy cinnamic acid and 20g of dimethyl diallyl ammonium chloride are dissolved in 305.9g of deionized water to obtain a monomer solution;

[0068] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 75℃ in a water bath, then 14g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 25min, then 12.0g of a 30wt% potassium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 5h, and then cooled to room temperature to obtain a high-temperature resistant oil well cement slurry retarder.

[0069] Example 6

[0070] The preparation method of the retarder provided in this example comprises the following steps:

[0071] Step 1, refer to example 1;

[0072] Step 2, 75g of 2-methyl-2-acrylamidopropanesulfonic acid, 15g of sodium allylsulfonate, 10g of maleic acid, 9g of p-hydroxycinnamic acid and 14g of dimethyldiallylammonium chloride are dissolved in 305.9g of deionized water to obtain a monomer solution;

[0073] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 80℃ in a water bath, then 10g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 20min, then 11.5g of a 30wt% ammonium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 4h, and then cooled to room temperature to obtain the retarder.

[0074] Example 7

[0075] The preparation method of the retarder provided in this example comprises the following steps:

[0076] Step 1, refer to example 1;

[0077] Step 2, 68g of 2-methyl-2-acrylamidopropanesulfonic acid, 18g of sodium allylsulfonate, 12g of maleic acid, 10g of p-hydroxycinnamic acid and 16g of dimethyldiallylammonium chloride are dissolved in 350g of deionized water to obtain a monomer solution;

[0078] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 75℃ in a water bath, then 12.5g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 35min, then 12.7g of a 30wt% ammonium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 5h, and cooled to room temperature to obtain a high-temperature resistant oil well cement slurry retarder.

[0079] Example 8

[0080] The preparation method of the retarder provided in the example includes the following steps:

[0081] Step 1, refer to example 1;

[0082] Step 2, 74g of 2-methyl-2-acrylamidopropanesulfonic acid, 20g of sodium allylsulfonate, 10g of maleic acid, 12g of p-hydroxycinnamic acid, and 18g of dimethyldiallylammonium chloride are dissolved in 402g of deionized water to obtain a monomer mixture solution;

[0083] Step 3, the monomer solution is transferred to a four-necked flask equipped with a stirrer, a thermometer, a constant pressure burette and a nitrogen inlet, stirred in a nitrogen atmosphere, and heated to 75℃ in a water bath, then 12.5g of modified nano zinc oxide is added after the pH of the solution is adjusted to 7 by adding a 30wt% sodium hydroxide solution, and stirred at 300r / min for 35min, then 12.7g of a 30wt% ammonium persulfate aqueous solution is slowly added dropwise, and refluxed at constant temperature for 5h, and cooled to room temperature to obtain a high-temperature resistant oil well cement slurry retarder.

[0084] Comparative Example 1

[0085] The preparation method of the retarder provided in the example includes the following steps:

[0086] Step 1, refer to example 1;

[0087] Step 2, 74g of 2-methyl-2-acrylamidopropanesulfonic acid, 20g of sodium allylsulfonate, 10g of maleic acid, 12g of p-hydroxycinnamic acid, and 18g of dimethyldiallylammonium chloride are dissolved in 402g of deionized water to obtain a monomer mixture solution;

[0088] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 60°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7. Add 12g of modified nano zinc oxide and stir at 300r / min for 30min. Then slowly add 11.2g of 30% ammonium persulfate aqueous solution. Reflux at a constant temperature for 5h and cool to room temperature to obtain the retarder.

[0089] Comparative Example 2

[0090] The preparation method of the retarder provided in this comparative example includes the following steps:

[0091] Step 1: Refer to Example 1;

[0092] Step 2: Weigh 60g of 2-methyl-2-acrylamidopropanesulfonic acid, 20g of sodium allyl sulfonate, 16g of itaconic acid, 8g of p-hydroxycinnamic acid, and 15g of dimethyl diallyl ammonium chloride and dissolve them in 357g of deionized water to obtain a monomer solution.

[0093] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 80°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 10g of modified nano zinc oxide and stir at 300r / min for 20min. Then slowly add 9.0g of 30% potassium persulfate aqueous solution, reflux at a constant temperature for 4h, and cool to room temperature to obtain the retarder.

[0094] Comparative Example 3

[0095] The preparation method of the retarder provided in this comparative example includes the following steps:

[0096] Step 1: Weigh 15g of nano zinc oxide, 30g of vinyltriethoxysilane, 600g of isopropanol and 150g of water, mix them evenly, and sonicate them in an ultrasonic nanomaterial disperser for 0.5 hours to obtain a dispersion. Reflux the dispersion in a 50°C water bath for 10 hours, centrifuge to obtain a solid, wash it with isopropanol and place it in an oven to heat at 85°C for 24 hours. Crush and grind the solid to obtain modified nano zinc oxide.

[0097] Step 2: Weigh 80g of 2-methyl-2-acrylamidopropanesulfonic acid, 25g of sodium allyl sulfonate, 14g of maleic acid, 10g of p-hydroxycinnamic acid, and 20g of dimethyl diallyl ammonium chloride and dissolve them in 447g of deionized water to obtain a monomer solution.

[0098] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 65°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 15g of modified nano zinc oxide and stir at 300r / min for 35min. Then slowly add 19.1g of 30% potassium persulfate aqueous solution, reflux at a constant temperature for 6h, and cool to room temperature to obtain the retarder.

[0099] Comparative Example 4

[0100] The preparation method of the retarder provided in this comparative example includes the following steps:

[0101] Step 1: Refer to Example 1;

[0102] Step 2: Weigh 85g of 2-methyl-2-acrylamidopropanesulfonic acid, 18g of sodium allyl sulfonate, 15g of maleic acid, and 25g of dimethyl diallyl ammonium chloride and dissolve them in 357.5g of deionized water to obtain a monomer solution.

[0103] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 70°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 13.5g of modified nano zinc oxide and stir at 300r / min for 40min. Then slowly add 12.0g of 30% ammonium persulfate aqueous solution and reflux at a constant temperature for 6h. Cool to room temperature to obtain the retarder.

[0104] Comparative Example 5

[0105] The preparation method of the retarder provided in this comparative example includes the following steps:

[0106] Weigh 65g of 2-methyl-2-acrylamidopropanesulfonic acid, 18g of sodium allyl sulfonate, 16g of maleic acid, 14g of p-hydroxycinnamic acid, and 20g of dimethyldiallylammonium chloride and dissolve them in 305.9g of deionized water to obtain a monomer solution. Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel, and nitrogen inlet. Stir under a nitrogen atmosphere and heat in a water bath to 75°C. Adjust the pH of the solution to 7 by adding 30% sodium hydroxide solution. Stir at 300r / min for 25min. Then slowly add 10.9g of 30% potassium persulfate aqueous solution. Reflux at a constant temperature for 5h and cool to room temperature to obtain a high-temperature resistant oil well cement slurry retarder.

[0107] Comparative Example 6

[0108] The preparation method of the retarder provided in this comparative example includes the following steps:

[0109] Step 1: Refer to Example 1;

[0110] Step 2: Weigh 50g of 2-methyl-2-acrylamidopropanesulfonic acid, 15g of sodium allyl sulfonate, 10g of maleic acid, 9g of p-hydroxycinnamic acid, and 14g of dimethyl diallyl ammonium chloride and dissolve them in 244.0g of deionized water to obtain a monomer solution.

[0111] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 80°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 10g of modified nano zinc oxide and stir at 300r / min for 20min. Then slowly add 9.4g of 30% ammonium persulfate aqueous solution, reflux at a constant temperature for 4h, and cool to room temperature to obtain the retarder.

[0112] Comparative Example 7

[0113] The preparation method of the retarder provided in this comparative example includes the following steps:

[0114] Step 1: Refer to Example 1;

[0115] Step 2: Weigh 68g of 2-methyl-2-acrylamidopropanesulfonic acid, 18g of sodium allyl sulfonate, 12g of maleic acid, 20g of p-hydroxycinnamic acid, and 16g of dimethyl diallyl ammonium chloride and dissolve them in 377.9g of deionized water to obtain a monomer solution.

[0116] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel, and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 75°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 12.5g of modified nano zinc oxide and stir at 300r / min for 35min. Then slowly add 12.5g of 30% ammonium persulfate aqueous solution and reflux at a constant temperature for 5h. Cool to room temperature to obtain a high-temperature resistant oil well cement slurry retarder.

[0117] Comparative Example 8

[0118] The preparation method of the retarder provided in this comparative example includes the following steps:

[0119] Step 1: Refer to Example 1;

[0120] Step 2: Weigh 74g of 2-methyl-2-acrylamidopropanesulfonic acid, 20g of sodium allyl sulfonate, 10g of maleic acid, and 12g of p-hydroxycinnamic acid and dissolve them in 348g of deionized water to obtain a monomer mixed solution.

[0121] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 60°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 14g of modified nano zinc oxide and stir at 300r / min for 40min. Then slowly add 10.6g of 30% ammonium persulfate aqueous solution, reflux at a constant temperature for 6h, and cool to room temperature to obtain the retarder.

[0122] Comparative Example 9

[0123] The preparation method of the retarder provided in this comparative example includes the following steps:

[0124] Step 1: Refer to Example 1;

[0125] Step 2: Weigh 74g of 2-methyl-2-acrylamidopropanesulfonic acid, 20g of sodium allyl sulfonate, 10g of maleic acid, 12g of p-hydroxycinnamic acid, and 30g of dimethyl diallyl ammonium chloride and dissolve them in 438.0g of deionized water to obtain a monomer mixed solution.

[0126] Step 3: Transfer the monomer solution to a four-necked flask equipped with a stirrer, thermometer, constant pressure titration funnel and nitrogen inlet. Stir in a nitrogen atmosphere and heat in a water bath to 60°C. Add 30% sodium hydroxide solution to adjust the pH of the solution to 7, then add 14g of modified nano zinc oxide and stir at 300r / min for 40min. Then slowly add 13.1g of 30% ammonium persulfate aqueous solution, reflux at a constant temperature for 6h, and cool to room temperature to obtain the retarder.

[0127] Thickening performance tests were conducted on the retarders provided in Examples 1-8 and Comparative Examples 1-9. The highest temperature that the retarders could withstand before failure was tested. For example, the retardation effect of the retarders was tested at 180°C. If the thickening curve was normal and there were no abnormal phenomena such as bulging or core formation, the test temperature was increased to 190°C and the test continued until the retarders failed. The temperature before the retarders failed was recorded as the highest temperature, and the compressive strength of the cement paste was tested at this temperature. The cement used was Jiahua G-grade oil well cement. A pressure thickener was used, and the test was conducted according to the cement paste compressive strength test method specified in Section 7 and the cement slurry thickening test method specified in Section 9 of GB / T19139-2012 "Test Methods for Oil Well Cement". The test results are shown in Table 1.

[0128] Table 1. Performance test results of the retarders provided in Examples 1-8 and Comparative Examples 1-9

[0129]

[0130]

[0131] According to the data provided in Table 1, compared with Comparative Examples 1-9, the retarder provided in Examples 1-8 can withstand temperatures up to 240℃. At 240℃, when the amount of retarder added is 0.5%-5%, the thickening time of the cement slurry is between 280-528 minutes. After the cement slurry system is cured for 24 hours, the compressive strength of the cement stone reaches more than 27.3 MPa, which meets the requirements of ultra-high temperature cementing.

[0132] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for preparing a retarder, characterized in that, Includes the following steps: Modified zinc oxide nanoparticles were obtained by modifying them with vinyltrimethoxysilane. A monomer solution was obtained by mixing 2-methyl-2-acrylamidopropanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, and dimethyldiallylammonium chloride. The modified nano zinc oxide and monomer solution are mixed and polymerized in the presence of an initiator. After the polymerization reaction is completed, the retarder is obtained. The mass ratio of 2-methyl-2-acrylamidopropanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, dimethyl diallyl ammonium chloride and modified nano zinc oxide is (60-85):(15-25):(10-16):(8-15):(12-25):(10-15).

2. The method according to claim 1, characterized in that, Modification of nano-zinc oxide using vinyltrimethoxysilane specifically includes the following steps: Nano zinc oxide and vinyltrimethoxysilane were dissolved in a solvent and treated at 40-60°C for 10-24 hours. After treatment, the solid particles were collected, washed, dried and pulverized to obtain the modified nano zinc oxide.

3. The method according to claim 1, characterized in that, The initiator is one or both of ammonium persulfate and potassium persulfate.

4. The method according to claim 1, characterized in that, The initiator is 2%-5% of the total mass of 2-methyl-2-acrylamidopropanesulfonic acid, sodium allyl sulfonate, maleic acid, p-hydroxycinnamic acid, and dimethyl diallyl ammonium chloride.

5. The method according to claim 1, characterized in that, The polymerization reaction is carried out at a temperature of 60-80℃ for 4-6 hours.

6. A retarder, characterized in that, Prepared by the method according to any one of claims 1-5.

7. A cement grout, characterized in that, Includes the retarder as described in claim 6.

8. The cement grout according to claim 7, characterized in that, The retarder has a mass of 0.5%-5% of the total mass of the cement slurry.

9. The cement grout according to claim 7 or 8, characterized in that, The thickening time of the cement slurry at 240℃ is 280-528 min, and the compressive strength of the cement slurry after curing for 24 h is greater than or equal to 27.3 MPa.

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