Three-dimensional dendritic macromolecular tackifier, preparation method thereof and drilling fluid containing three-dimensional dendritic macromolecular tackifier

Abstract

The invention provides a three-dimensional dendritic macromolecular tackifier as well as a preparation method and application thereof. The three-dimensional dendritic macromolecular tackifier is prepared from the following raw materials: a hyperbranched polymer and a grafting monomer, the hyperbranched polymer is prepared from the following raw materials: triethanolamine, p-phenylenediamine and a chain transfer agent. And the chain transfer agent is prepared from 2-cyano-2-propyl benzo disulfide. The three-dimensional dendritic macromolecular tackifier has good high-temperature and high-salt resistance, can also have a good tackifying effect under high-temperature and high-salt conditions, and can be used for water-based drilling fluids of various deep wells and ultra-deep wells.

Description

Technical Field

[0001] The invention belongs to the technical field of drilling fluid treatment agents, and in particular relates to a three-dimensional dendritic macromolecular tackifier and a preparation method thereof, and a drilling fluid containing the same. Background Art

[0002] With the increasing demand for oil and natural gas, oil and gas production has gradually entered the deep and ultra-deep development stage. The increasingly high formation temperature requires the relevant treatment agents of drilling fluid to have higher high temperature and salt resistance.

[0003] Thickener is an important treatment agent to maintain the colloid properties of drilling fluid and plays a role in adjusting the rheological properties of drilling fluid. Traditional thickeners are mainly linear macromolecules, and the molecular chains are easily entangled with each other. Under high temperature, they will undergo irreversible changes such as degradation and cross-linking, resulting in a significant decrease in viscosity.

[0004] Patent CN103113518A discloses a drilling fluid thickener and a preparation method thereof. The drilling fluid thickener mixes water-soluble monomers and hydrophobic monomers of different ionic types and performs polymerization reaction to prepare an amphoteric hydrophobic associating water-soluble drilling fluid thickener. However, the thickening performance of the thickener under high temperature and high salt conditions needs to be further improved.

[0005] For example, patent CN106608946A discloses a copolymer for drilling fluid thickener and a preparation method thereof. The obtained thickener contains N,N-dimethylacrylamide structural units, zwitterionic structural units, starch units and cationic polyamine structural units, which can improve the temperature and salt resistance of the drilling fluid; patent CN117844460A discloses a cellulose thickener for drilling fluid and a preparation method thereof. By selecting specific raw materials, the temperature and salt resistance of the drilling fluid can be improved; however, the high temperature and high salt resistance of the above-mentioned drilling fluids need to be further improved.

[0006] Therefore, developing a drilling fluid thickener that has good high temperature and high salt resistance and still has a good viscosity increasing effect under high temperature and high salt conditions is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0007] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a three-dimensional dendritic macromolecular thickener and a preparation method thereof, and a drilling fluid containing the same; the three-dimensional dendritic macromolecular thickener solves the problem that traditional thickeners are prone to mutual entanglement of molecular chains, and undergo irreversible changes such as degradation and cross-linking under the action of high temperature and high salt, resulting in a significant decrease in viscosity.

[0008] To achieve this object, the present invention adopts the following technical solutions:

[0009] In a first aspect, the present invention provides a three-dimensional dendritic macromolecular thickener, wherein the raw materials for preparing the three-dimensional dendritic macromolecular thickener include a hyperbranched polymer and a grafted monomer; the raw materials for preparing the hyperbranched polymer include triethanolamine, p-phenylenediamine and a chain transfer agent; the chain transfer agent includes 2-cyano-2-propylbenzodisulfide.

[0010] The hyperbranched polymer has a high degree of branching, a higher functional group density, a more compact structure and a large number of active end groups, can be grafted with more branches, has good solubility and stability, has large steric hindrance, and has good temperature and salt resistance. In the present invention, a specific type of hyperbranched polymer and a grafting monomer are used as raw materials, and linear branches are grafted into the molecular chain of the hyperbranched polymer. The obtained thickener has a three-dimensional dendritic molecular structure, good stability, and can form a three-dimensional space grid in the drilling fluid, so that the viscosity decay rate of the thickener is reduced after aging. In addition, the dendritic molecule has large steric hindrance, the molecular chain is not easy to curl, the guest molecule has a stronger binding force in the cavity, has good high temperature and high salt resistance, can also have a good thickening effect under high temperature and high salt conditions, and can be used for a variety of deep well and ultra-deep well water-based drilling fluids.

[0011] Preferably, the mass ratio of triethanolamine to p-phenylenediamine is 1:(0.5-2.5), wherein the specific value in (0.5-2.5) can be, for example, 0.5, 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.95, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, etc.

[0012] Preferably, based on the total mass of triethanolamine and p-phenylenediamine as 100%, the mass of the chain transfer agent is 0.2-0.6%, for example, it can be 0.2%, 0.22%, 0.24%, 0.26%, 0.28%, 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, 0.52%, 0.54%, 0.56%, 0.58%, 0.6% and the like.

[0013] In the present invention, triethanolamine, p-phenylenediamine and a specific type of chain transfer agent are used as raw materials, so that the molecular weight distribution of the hyperbranched polymer is narrow, and it is conducive to forming a three-dimensional dendritic molecular structure, so that the thickener still has a good thickening effect under high temperature and high salt conditions; without a specific raw material ratio and type, the obtained hyperbranched polymer has a wide molecular weight distribution or affects the subsequent grafting effect, and the thickener with a three-dimensional dendritic molecular structure cannot be obtained, which leads to poor high temperature and high salt resistance and poor thickening effect.

[0014] Preferably, the weight average molecular weight of the hyperbranched polymer is 150000-350000 g / mol, for example, 150000 g / mol, 160000 g / mol, 170000 g / mol, 180000 g / mol, 190000 g / mol, 200000 g / mol, 210000 g / mol, 220000 g / mol, 230000 g / mol, 240000 g / mol, 250000 g / mol, 260000 g / mol, 270000 g / mol, 280000 g / mol, 290000 g / mol, 300000 g / mol, 310000 g / mol, 320000 g / mol, 330000 g / mol, 340000 g / mol, 350000 g / mol, etc.

[0015] Preferably, the polydispersity coefficient of the hyperbranched polymer is 1.7 to 2.2, for example, it can be 1.7, 1.72, 1.74, 1.76, 1.78, 1.8, 1.82, 1.84, 1.86, 1.88, 1.9, 1.92, 1.94, 1.96, 1.98, 2, 2.02, 2.04, 2.06, 2.08, 2.1, 2.12, 2.14, 2.16, 2.18, 2.2, etc.

[0016] Preferably, the mass ratio of the hyperbranched polymer to the grafted monomer is 1:(35-45), wherein the specific value in (35-45) can be, for example, 35, 35.2, 35.5, 35.8, 36, 36.2, 36.5, 36.8, 37, 37.2, 37.5, 37.8, 38, 38.2, 38.5, 38.8, 39, 39.2, 39.5, 39.8, 40, 40.2, 40.5, 40.8, 41, 41.2, 41.5, 41.8, 42, 42.2, 42.5, 42.8, 43, 43.2, 43.5, 43.8, 44, 44.2, 44.5, 44.8, 45, etc.

[0017] In the present invention, when there are too few hyperbranched polymers, a single branch chain will be too long, and the molecular chains are easily entangled with each other, and irreversible changes such as degradation and cross-linking will occur under the action of high temperature and high salt, resulting in poor viscosity enhancement effect; when there are too many hyperbranched polymers, the number of branches grafted on a single hyperbranched polymer will decrease, and a three-dimensional dendritic structure cannot be formed. In addition, the hyperbranched polymers may interact with each other, changing the spatial configuration of the polymer, which will also affect the viscosity enhancement effect, resulting in a poor viscosity enhancement effect.

[0018] Preferably, the grafting monomer includes at least one of aromatic vinyl sulfonate, unsaturated sulfonic acid monomer, acrylamide monomer, long carbon chain unsaturated quaternary ammonium salt monomer or phthalimide.

[0019] Preferably, the aromatic vinyl sulfonate comprises sodium p-styrene sulfonate.

[0020] Preferably, the unsaturated sulfonic acid monomer includes 2-acrylamido-2-methylpropanesulfonic acid.

[0021] Preferably, the long carbon chain unsaturated quaternary ammonium salt monomer includes C10-C17 alkyl dimethyl allyl ammonium chloride, and the C10-C17 alkyl group may be, for example, C10, C11, C12, C13, C14, C15, C16, C17, etc.

[0022] Preferably, the acrylamide comprises acrylamide and / or methacrylamide.

[0023] Preferably, the long carbon chain unsaturated quaternary ammonium salt monomer includes hexadecyl dimethyl allyl ammonium chloride.

[0024] In the present invention, the tackifier obtained by using C10-C17 alkyl dimethyl allyl ammonium chloride has a better tackifying effect; if the carbon chain length is too short or too long, the tackifying effect will be poor.

[0025] Preferably, the grafting monomer includes a combination of aromatic vinyl sulfonate, unsaturated sulfonic acid monomer, acrylamide monomer, long carbon chain unsaturated quaternary ammonium salt monomer and phthalimide.

[0026] Preferably, the mass ratio of the aromatic vinyl sulfonate, the unsaturated sulfonic acid monomer, the acrylamide monomer, the long carbon chain unsaturated quaternary ammonium salt monomer and the phthalimide is (1-3):(1-3):(0.5-1.5):(1-3):1, wherein the specific values ​​in (1-3) can be, for example, 1, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7 , 2.8, 2.9, 3, etc.; the specific values ​​in (0.5-1.5) can be, for example, 0.5, 0.52, 0.54, 0.56, 0.58, 0.6, 0.62, 0.64, 0.66, 0.68, 0.7, 0.72, 0.74, 0.76, 0.78, 0.8, 0.82, 0.84, 0.86, 0.88, 0.9, 0.92, 0.94, 0.96, 0.98, 1, 1.1, 1.2, 1.3, 1.4, 1.5, etc.

[0027] In the present invention, aromatic vinyl sulfonate contains benzene rings, which can enhance the rigidity of molecular chains; the sulfonic acid group of unsaturated sulfonic acid monomers has a strong hydration effect; long carbon chain unsaturated quaternary ammonium salt monomers have high reactivity and are conducive to the growth of branched chains; phthalimide has an ortho-position five- and six-membered ring structure, which can play a role in regulating the progress of the reaction; large electron cloud steric hindrance can regulate the overall energy of the reaction system, thereby changing the copolymerization tendency between monomers and obtaining a molecular chain with a specific structure; and by selecting the combination of the above monomers, the obtained tackifier has a better tackifying effect and good high temperature and high salt resistance.

[0028] Preferably, the preparation raw materials further include an initiator.

[0029] Preferably, the initiator is 5-25% of the mass of the hyperbranched polymer, for example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.

[0030] Preferably, the initiator comprises an azo initiator and / or a peroxide initiator.

[0031] In the present invention, the initiator includes azobisisobutylamidine hydrochloride.

[0032] In a second aspect, the present invention provides a method for preparing the three-dimensional dendritic macromolecular thickener according to the first aspect, the preparation method comprising the following steps:

[0033] The hyperbranched polymer, the grafted monomer and the solvent A are mixed and subjected to a first reaction to obtain the three-dimensional dendritic macromolecular thickener.

[0034] Preferably, the method for preparing the hyperbranched polymer comprises the following steps:

[0035] The triethanolamine, p-phenylenediamine and solvent B are mixed to obtain a first solution; the first solution is then mixed with a chain transfer agent to perform a second reaction to obtain the hyperbranched polymer.

[0036] Preferably, the solvent B comprises N,N-dimethylformamide, and the total mass percentage of triethanolamine and p-phenylenediamine in the first solution is 20-35%, for example, it can be 20%, 22%, 23%, 24%, 25%, 26%, 28%, 29%, 30%, 31%, 32%, 33%, 34%, 35% and the like.

[0037] Preferably, the temperature of the second reaction is 55-80°C, for example, it can be 55°C, 56°C, 58°C, 60°C, 62°C, 64°C, 65°C, 66°C, 68°C, 70°C, 72°C, 74°C, 76°C, 78°C, 80°C, etc., more preferably 55-65°C.

[0038] Preferably, the second reaction time is 10 to 20 h, for example, 10 h, 12 h, 14 h, 15 h, 16 h, 18 h, 20 h, etc.

[0039] Preferably, the second reaction is carried out in the presence of a protective atmosphere.

[0040] In the present invention, the protective atmosphere includes but is not limited to nitrogen.

[0041] Preferably, after the second reaction, a post-treatment step is further included, and the post-treatment includes washing and / or reduced pressure distillation.

[0042] In the present invention, the washing solvent includes acetone.

[0043] Preferably, the raw material of the mixture of the hyperbranched polymer, the grafting monomer and the solvent A further comprises an initiator and / or a pH regulator.

[0044] In the present invention, the pH adjuster includes an alkaline compound, exemplarily including sodium hydroxide.

[0045] Preferably, the solvent A comprises water, and the mass of the solvent A is 1.8 to 3.2 times the mass of the grafted monomer, for example, it can be 1.8 times, 1.9 times, 2 times, 2.1 times, 2.2 times, 2.3 times, 2.4 times, 2.5 times, 2.6 times, 2.7 times, 2.8 times, 2.9 times, 3 times, etc.

[0046] Preferably, the method for mixing the hyperbranched polymer, the grafted monomer and the solvent A comprises: mixing at least one of aromatic vinyl sulfonate, unsaturated sulfonic acid monomer, acrylamide monomer and phthalimide with the solvent A, then adding an optional long carbon chain unsaturated quaternary ammonium salt monomer thereto, adjusting the pH value to 7-8, mixing and dispersing, and then adding the hyperbranched polymer and the initiator thereto for mixing.

[0047] In the present invention, in the preparation method, after adding the hyperbranched polymer, the system temperature is raised to the first reaction temperature, and then the initiator is added.

[0048] Preferably, the temperature of the first reaction is 60-80°C, for example, 60°C, 65°C, 70°C, 75°C, 80°C, etc.; the time is 3-6h, for example, 3h, 4h, 5h, 6h, etc.

[0049] Preferably, the first reaction is carried out in the presence of a protective atmosphere, which includes but is not limited to nitrogen.

[0050] Preferably, after the first reaction, a post-treatment step is further included, and the post-treatment includes precipitation, purification and / or drying.

[0051] In the present invention, the post-treatment after the first reaction includes: cooling the gel-state liquid obtained by the reaction to room temperature, then diluting and dissolving it with water, precipitating it with anhydrous acetone, soaking it in acetone for more than 24 hours, and then purifying it with ethanol reflux extraction for at least 12 hours. After the purification is completed, drying it at 80-100°C for 12-36 hours to obtain the three-dimensional dendritic macromolecular thickener.

[0052] In a third aspect, the present invention provides a drilling fluid, wherein the drilling fluid comprises the three-dimensional dendritic macromolecular thickener according to the first aspect.

[0053] Preferably, the mass percentage of the three-dimensional dendritic macromolecular thickener in the drilling fluid is 0.3-0.5%, for example, it can be 0.3%, 0.32%, 0.34%, 0.36%, 0.38%, 0.4%, 0.42%, 0.44%, 0.46%, 0.48%, 0.5%, etc.

[0054] In the present invention, the three-dimensional dendritic macromolecular thickener can achieve good thickening effect with a relatively small addition amount, thereby reducing the cost.

[0055] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

[0056] The system refers to an equipment system, a device system or a production device.

[0057] Compared with the prior art, the present invention has the following beneficial effects:

[0058] The three-dimensional dendritic macromolecular thickener provided by the present invention adopts a specific type of hyperbranched polymer and a grafted monomer as raw materials, and linear branches are grafted into the molecular chain of the hyperbranched polymer. The obtained thickener has a three-dimensional dendritic molecular structure and good stability, and can form a three-dimensional spatial grid in the drilling fluid, so that the viscosity decay rate of the thickener is reduced after aging; in addition, the dendritic molecules have large steric hindrance, the molecular chains are not easy to curl, and have good resistance to high temperature and high salt. It can also have a good thickening effect under high temperature and high salt conditions, and can be used for a variety of deep well and ultra-deep well water-based drilling fluids. DETAILED DESCRIPTION

[0059] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0060] In the present invention, the weight average molecular weight and the polydispersity coefficient can be tested by gel permeation chromatography.

[0061] Example 1

[0062] This embodiment provides a three-dimensional dendritic macromolecular thickener, wherein the raw materials for preparing the three-dimensional dendritic macromolecular thickener include a hyperbranched polymer, a grafted monomer and azobisisobutyramidine hydrochloride; the mass ratio of the hyperbranched polymer to the grafted monomer is 1:40, and the mass of the azobisisobutyramidine hydrochloride is 8.2% of the mass of the hyperbranched polymer.

[0063] The raw materials for preparing the hyperbranched polymer include triethanolamine and p-phenylenediamine in a mass ratio of 1:1.5; and also include 2-cyano-2-propylbenzodisulfide accounting for 0.4% of the total mass of triethanolamine and p-phenylenediamine; the weight average molecular weight of the hyperbranched polymer is 225080, and the polydispersity coefficient is 1.93.

[0064] The grafting monomers include sodium p-styrene sulfonate, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide, hexadecyl dimethyl allyl ammonium chloride and phthalimide in a mass ratio of 2:2:1:2:1.

[0065] This embodiment provides a method for preparing a three-dimensional dendritic macromolecular thickener, which specifically includes the following steps:

[0066] (1) According to the formula, triethanolamine and p-phenylenediamine are mixed with N,N-dimethylformamide and dissolved completely to obtain solution A; the total mass percentage of triethanolamine and p-phenylenediamine in the solution A is 33.3%; then, solution A is added to a Schlenk reaction tube containing 2-cyano-2-propylbenzodisulfide, and the gas in the Schlenk reaction tube is vacuumed and removed by repeating a 30° C. freezing-vacuuming-normal temperature thawing process three times, and then sealed; the sealed Schlenk reaction tube is placed in an oil bath at 60° C. for reaction for 15 hours; after the reaction is completed, the product is washed with acetone for 5 times, and then vacuum distilled to obtain a hyperbranched polymer.

[0067] (2) Sodium p-styrene sulfonate, AMPS, acrylamide, phthalimide and deionized water are mixed according to the formula amount and stirred thoroughly until they are completely dissolved; the mass of the deionized water is 2.05 times the total mass of the sodium p-styrene sulfonate, AMPS, acrylamide and phthalimide; then, hexadecyl dimethyl allyl ammonium chloride is added thereto, and a pH adjuster (NaOH) is added to adjust the pH to 7-8, and after stirring until fully dispersed, the hyperbranched polymer obtained in step (1) is added according to the formula amount, the temperature is raised to 70° C., azobisisobutylamidine hydrochloride (the mass is 8.2% of the mass of the hyperbranched polymer) is added, nitrogen is continuously passed for 30 minutes, and the reaction is performed for 4 hours to obtain a gel-like liquid, the gel-like liquid is cooled to room temperature, diluted and dissolved with water, precipitated with anhydrous acetone, soaked in acetone for 24 hours, and then purified by reflux extraction with ethanol for 12 hours. The obtained product is dried at 90° C. for 24 hours, and the light yellow powder obtained after pulverization is the three-dimensional dendritic macromolecular thickener.

[0068] Example 2

[0069] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from Embodiment 1 only in that, in the preparation method, the mass of N,N-dimethylformamide is increased in step (1) so that the total mass percentage of triethanolamine and p-phenylenediamine in the solution A is 25%; in step (2), the mass of deionized water is increased so that its mass is 4.1 times the total mass of sodium p-styrene sulfonate, AMPS, acrylamide and phthalimide; other raw materials, amounts and preparation methods are the same as those in Embodiment 1; the weight average molecular weight of the hyperbranched polymer is 287505, and the polydispersity coefficient is 1.74.

[0070] Example 3

[0071] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Example 1 only in that the mass of azobisisobutyramidine hydrochloride is increased so that the mass of the azobisisobutyramidine hydrochloride is 20.5% of the mass of the hyperbranched polymer, and other raw materials, amounts and preparation methods are the same as those in Example 1; the weight average molecular weight of the hyperbranched polymer is 265831, and the polydispersity coefficient is 1.58.

[0072] Example 4

[0073] This embodiment provides a three-dimensional dendritic macromolecular thickener, wherein the raw materials for preparing the three-dimensional dendritic macromolecular thickener include a hyperbranched polymer, a grafted monomer and azobisisobutyramidine hydrochloride; the mass ratio of the hyperbranched polymer to the grafted monomer is 1:35, and the mass of the azobisisobutyramidine hydrochloride is 8.2% of the mass of the hyperbranched polymer.

[0074] The raw materials for preparing the hyperbranched polymer include triethanolamine and p-phenylenediamine in a mass ratio of 1:0.8; and also include 2-cyano-2-propylbenzodisulfide accounting for 0.3% of the total mass of triethanolamine and p-phenylenediamine; the weight average molecular weight of the hyperbranched polymer is 198762, and the polydispersity coefficient is 1.72.

[0075] The grafting monomers include sodium p-styrene sulfonate, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide, hexadecyl dimethyl allyl ammonium chloride and phthalimide in a mass ratio of 1:3:0.5:3:1.

[0076] This embodiment provides a method for preparing a three-dimensional dendritic macromolecular thickener, and the specific steps are the same as those in Embodiment 1.

[0077] Example 5

[0078] This embodiment provides a three-dimensional dendritic macromolecular thickener, wherein the raw materials for preparing the three-dimensional dendritic macromolecular thickener include a hyperbranched polymer, a grafted monomer and azobisisobutyramidine hydrochloride; the mass ratio of the hyperbranched polymer to the grafted monomer is 1:45, and the mass of the azobisisobutyramidine hydrochloride is 8.2% of the mass of the hyperbranched polymer.

[0079] The raw materials for preparing the hyperbranched polymer include triethanolamine and p-phenylenediamine in a mass ratio of 1:2.4; and also include 2-cyano-2-propylbenzodisulfide accounting for 0.5% of the total mass of triethanolamine and p-phenylenediamine. The weight average molecular weight of the hyperbranched polymer is 264968, and the polydispersity coefficient is 1.58.

[0080] The grafting monomers include sodium p-styrene sulfonate, 2-acrylamido-2-methylpropane sulfonic acid (AMPS), acrylamide, hexadecyl dimethyl allyl ammonium chloride and phthalimide in a mass ratio of 3:1:1.5:1:1.

[0081] This embodiment provides a method for preparing a three-dimensional dendritic macromolecular thickener, and the specific steps are the same as those in Embodiment 1.

[0082] Example 6

[0083] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Embodiment 1 only in that the total mass of triethanolamine and p-phenylenediamine remains unchanged, the mass ratio is 1:0.2, and other raw materials, amounts and preparation methods are the same as those in Embodiment 1.

[0084] Example 7

[0085] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Embodiment 1 only in that the total mass of triethanolamine and p-phenylenediamine remains unchanged, the mass ratio is 1:3, and other raw materials, amounts and preparation methods are the same as those in Embodiment 1.

[0086] Example 8

[0087] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from the embodiment 1 only in that the mass of the 2-cyano-2-propylbenzodisulfide is 0.1% of the total mass of triethanolamine and p-phenylenediamine, and the other raw materials, amounts and preparation methods are the same as those in the embodiment 1.

[0088] Example 9

[0089] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from the embodiment 1 only in that the mass of the 2-cyano-2-propylbenzodisulfide is 0.8% of the total mass of triethanolamine and p-phenylenediamine, and the other raw materials, amounts and preparation methods are the same as those in the embodiment 1.

[0090] Example 10

[0091] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from Embodiment 1 only in that, in the preparation method, the reaction temperature in step (1) is 70° C., i.e., placed in an oil bath at 70° C., and other raw materials, amounts and preparation methods are the same as those in Embodiment 1. The weight average molecular weight of the hyperbranched polymer is 189207, and the polydispersity coefficient is 2.06.

[0092] Embodiment 11

[0093] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from Embodiment 1 only in that, in the preparation method, the reaction temperature in step (1) is 80° C., i.e., placed in an oil bath at 80° C., and other raw materials, amounts and preparation methods are the same as those in Embodiment 1. The weight average molecular weight of the hyperbranched polymer is 161192, and the polydispersity coefficient is 2.12.

[0094] Example 12

[0095] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Embodiment 1 only in that the total mass of the hyperbranched polymer and the grafted monomer remains unchanged, the mass ratio is 1:25, and other raw materials, proportions and preparation methods are the same as those in Embodiment 1.

[0096] Embodiment 13

[0097] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Embodiment 1 only in that the total mass of the hyperbranched polymer and the grafted monomer remains unchanged, the mass ratio is 1:50, and other raw materials, proportions and preparation methods are the same as those in Embodiment 1.

[0098] Embodiment 14

[0099] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from Embodiment 1 only in that the total mass of the grafted monomer remains unchanged, no phthalimide is present, the proportion of other grafted monomers remains unchanged, and other raw materials, proportions and preparation methods are the same as those in Embodiment 1.

[0100] Embodiment 15

[0101] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from the embodiment 1 only in that hexadecyldimethylallylammonium chloride is replaced with dimethyldiallylammonium chloride of equal mass, and other raw materials, proportions and preparation methods are the same as those in the embodiment 1.

[0102] Example 16

[0103] This embodiment provides a three-dimensional dendritic macromolecular thickener, which differs from the embodiment 1 only in that hexadecyl dimethyl allyl ammonium chloride is replaced with an equal mass of octadecyl dimethyl allyl ammonium chloride, and other raw materials, proportions and preparation methods are the same as those in the embodiment 1.

[0104] Embodiment 17

[0105] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Example 1 only in that the total mass of the grafted monomer remains unchanged, including sodium p-styrene sulfonate, AMPS, acrylamide, hexadecyl dimethyl allyl ammonium chloride and phthalimide in a mass ratio of 0.5:5:0.1:5:1, and other raw materials, proportions and preparation methods are the same as those in Example 1.

[0106] Embodiment 18

[0107] This embodiment provides a three-dimensional dendritic macromolecular thickener, which is different from Example 1 only in that the total mass of the grafted monomer remains unchanged, including sodium p-styrene sulfonate, AMPS, acrylamide, hexadecyl dimethyl allyl ammonium chloride and phthalimide in a mass ratio of 5:0.5:2:0.5:1, and other raw materials, proportions and preparation methods are the same as those in Example 1.

[0108] Comparative Example 1

[0109] This comparative example provides a tackifier, which is different from Example 1 only in that the raw materials for preparing the hyperbranched polymer do not contain a chain transfer agent, and other raw materials, proportions and preparation methods are the same as those in Example 1.

[0110] Comparative Example 2

[0111] This comparative example provides a tackifier, which differs from Example 1 only in that 2-cyano-2-propylbenzodisulfide is replaced by 4-cyanopentanoic acid dithiobenzoate, and other raw materials, proportions and preparation methods are the same as those in Example 1.

[0112] Comparative Example 3

[0113] This comparative example provides a tackifier, which differs from Example 1 only in that p-phenylenediamine is replaced by m-phenylenediamine, and other raw materials, proportions and preparation methods are the same as those in Example 1.

[0114] Comparative Example 4

[0115] The comparative example provides a three-dimensional dendritic macromolecular thickener, which differs from Example 1 only in that the hyperbranched polymer is replaced by a hyperbranched polysiloxane, and the preparation method of the hyperbranched polysiloxane comprises: mixing ethanol and water in a volume ratio of 1:10 to prepare 100 mL of an ethanol aqueous solution; adding 5 g of γ-methacryloxypropyltrimethoxysilane and 5 g of dimethoxy(methyl)phenylsilane to the above-mentioned ethanol aqueous solution under nitrogen protection and stirring, adjusting the pH of the system to 5.5 with a 10% mass fraction of HCl solution, and reacting at a constant temperature of 60° C. for 4 hours; after the reaction is completed, drying the obtained product at 65° C. to constant weight to obtain a hyperbranched polysiloxane; other raw materials, proportions and preparation methods are the same as those in Example 1.

[0116] Performance Testing

[0117] The viscosity enhancers provided in Examples 1 to 18 and Comparative Examples 1 to 4 were formulated into drilling fluids for relevant performance tests.

[0118] Preparation of base slurry: Add 40g of bentonite to 1000mL of water, stir at 100r / min for 2h, and leave to cure at room temperature for 24h to obtain fresh water base slurry. Then, add 300g of NaCl and 50g of CaCl2 to the fresh water base slurry, stir for 1h, and leave to cure at room temperature for 24h to obtain a high-salt base slurry containing 30% NaCl and 5% CaCl2.

[0119] Take 400 mL of the high-salt base slurry, add 0.5% of the viscosity enhancers provided in Examples 1 to 18 and Comparative Examples 1 to 4 respectively at a stirring speed of 5000 r / min, continue stirring for 20 minutes, and then use a six-speed viscometer to measure the initial apparent viscosity (AV0); then after aging at 200°C for 16 hours, use a six-speed viscometer to measure the apparent viscosity after aging (AV1), and calculate the viscosity retention rate; viscosity retention rate = AV1 / AV0×100%.

[0120] The base slurry without viscosity enhancer was used as the control group.

[0121] The specific test results are shown in Table 1.

[0122] Table 1

[0123] <![CDATA[AV0(mPa·s)]]> <![CDATA[AV1(mPa·s)]]> Viscosity retention rate (%) Example 1 68 64 94.12 Example 2 66 64 96.97 Example 3 70 66 94.27 Example 4 69 66 95.65 Example 5 68 64.5 94.85 Example 6 56 51 91.07 Example 7 58 50.5 87.07 Example 8 54 47 87.04 Example 9 58 49 84.48 Example 10 65 60 92.31 Embodiment 11 63 56 88.89 Example 12 59 55 93.22 Embodiment 13 56 51 91.07 Embodiment 14 53 48.5 91.51 Embodiment 15 57 52 91.23 Example 16 58 50 86.21 Embodiment 17 57.5 52 90.43 Embodiment 18 51 44 86.27 Comparative Example 1 59 45 76.27 Comparative Example 2 60 47.5 79.17 Comparative Example 3 54.5 40 73.39 Comparative Example 4 49 36.5 74.49 Control group 24 11 45.83

[0124] As can be seen from Table 1, the three-dimensional dendritic macromolecular thickener provided by the present invention adopts a specific type of hyperbranched polymer and a grafted monomer as raw materials, and grafts linear branches into the molecular chain of the hyperbranched polymer to obtain a thickener with a three-dimensional dendritic molecular structure, which has a good thickening effect, so that the initial apparent viscosity of the drilling fluid is ≥51mPa·s; and under high temperature and high salt conditions, it can still maintain good dispersion in water and effectively maintain the viscosity of the drilling fluid; the viscosity retention rate of the drilling fluid containing 30wt% NaCl and 5wt% CaCl2 after aging at 200°C is ≥84.48%, and can even reach 94% or above.

[0125] It can be seen from Comparative Examples 1 to 4 that when there is no chain transfer agent in the raw materials for preparing the hyperbranched polymer, or the tackifier obtained from the raw materials is not the specific raw materials of the present invention, the tackifying effect is poor and the high temperature and high salt resistance effect is poor.

[0126] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-dimensional dendritic macromolecular thickener, characterized in that: The raw materials for preparing the three-dimensional dendritic macromolecular viscosity enhancer include hyperbranched polymers and grafted monomers; The raw materials for preparing the hyperbranched polymer include triethanolamine, p-phenylenediamine and a chain transfer agent; The chain transfer agent includes 2-cyano-2-propylbenzodisulfide.

2. The three-dimensional dendritic macromolecular thickener according to claim 1, characterized in that: The mass ratio of triethanolamine to p-phenylenediamine is 1:(0.5-2.5); Preferably, based on the total mass of triethanolamine and p-phenylenediamine being 100%, the mass of the chain transfer agent is 0.2-0.6%.

3. The three-dimensional dendritic macromolecular thickener according to claim 1 or 2, characterized in that: The weight average molecular weight of the hyperbranched polymer is 150,000 to 350,000 g / mol; Preferably, the polydispersity coefficient of the hyperbranched polymer is 1.7 to 2.

2.

4. The three-dimensional dendritic macromolecular thickener according to any one of claims 1 to 3, characterized in that: The mass ratio of the hyperbranched polymer to the grafted monomer is 1:(35-45).

5. The three-dimensional dendritic macromolecular thickener according to any one of claims 1 to 4, characterized in that: The grafting monomer includes at least one of aromatic vinyl sulfonate, unsaturated sulfonic acid monomer, acrylamide monomer, long carbon chain unsaturated quaternary ammonium salt monomer or phthalimide; Preferably, the aromatic vinyl sulfonate comprises sodium p-styrene sulfonate; Preferably, the unsaturated sulfonic acid monomer includes 2-acrylamido-2-methylpropanesulfonic acid; Preferably, the long carbon chain unsaturated quaternary ammonium salt monomer includes C10-C17 alkyl dimethyl allyl ammonium chloride; Preferably, the acrylamide comprises acrylamide and / or methacrylamide; Preferably, the long carbon chain unsaturated quaternary ammonium salt monomer includes hexadecyl dimethyl allyl ammonium chloride.

6. The three-dimensional dendritic macromolecular thickener according to any one of claims 1 to 5, characterized in that: The grafting monomers include a combination of aromatic vinyl sulfonate, unsaturated sulfonic acid monomers, acrylamide monomers, long carbon chain unsaturated quaternary ammonium salt monomers and phthalimide; Preferably, the mass ratio of the aromatic vinyl sulfonate, the unsaturated sulfonic acid monomer, the acrylamide monomer, the long carbon chain unsaturated quaternary ammonium salt monomer and phthalimide is (1-3):(1-3):(0.5-1.5):(1-3):1; Preferably, the preparation raw materials further include an initiator; Preferably, the initiator is 5 to 25% of the mass of the hyperbranched polymer; Preferably, the initiator comprises an azo initiator and / or a peroxide initiator; Preferably, the initiator comprises azobisisobutyramidine hydrochloride.

7. A method for preparing the three-dimensional dendritic macromolecular thickener according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: The hyperbranched polymer, the grafted monomer and the solvent A are mixed and subjected to a first reaction to obtain the three-dimensional dendritic macromolecular thickener.

8. The preparation method according to claim 7, characterized in that: The preparation method of the hyperbranched polymer comprises the following steps: Mixing triethanolamine, p-phenylenediamine and solvent B to obtain a first solution; then mixing the first solution with a chain transfer agent, performing a second reaction, and obtaining the hyperbranched polymer; Preferably, the solvent B comprises N,N-dimethylformamide, and the total mass percentage of triethanolamine and p-phenylenediamine in the first solution is 20-35%; Preferably, the temperature of the second reaction is 55-80°C; Preferably, the second reaction time is 10 to 20 hours; Preferably, the second reaction is carried out in the presence of a protective atmosphere; Preferably, after the second reaction, a post-treatment step is further included, and the post-treatment includes washing and / or reduced pressure distillation.

9. The preparation method according to claim 7 or 8, characterized in that: The raw material of the hyperbranched polymer, grafted monomer and solvent A also includes an initiator and / or a pH regulator; Preferably, the solvent A comprises water, and the mass of the solvent A is 1.8 to 3.2 times the mass of the grafted monomer; Preferably, the method for mixing the hyperbranched polymer, the grafted monomer and the solvent A comprises: mixing at least one of aromatic vinyl sulfonate, unsaturated sulfonic acid monomer, acrylamide monomer and phthalimide with the solvent A, then adding an optional long carbon chain unsaturated quaternary ammonium salt monomer thereto, adjusting the pH value to 7-8, mixing and dispersing, and then adding the hyperbranched polymer and the initiator thereto and mixing; Preferably, the temperature of the first reaction is 60-80°C and the time is 3-6h; Preferably, the first reaction is carried out in the presence of a protective atmosphere; Preferably, after the first reaction, a post-treatment step is further included, and the post-treatment includes precipitation, purification and / or drying.

10. A drilling fluid, characterized in that: The drilling fluid comprises the three-dimensional dendritic macromolecular thickener according to any one of claims 1 to 6.