A temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid and a preparation method thereof

Abstract

The application belongs to the technical field of oil field drilling, and particularly relates to a temperature-resistant and salt-resistant modified sulfonated phenolic aldehyde resin for drilling fluid and a preparation method thereof. The modified sulfonated phenolic aldehyde resin is prepared by using a functional modification reagent to functionalize and modify the phenolic aldehyde resin to obtain a phenolic aldehyde resin modified material, and then performing a free radical polymerization reaction with a double-ion polymerization monomer. The quaternary ammonium cation in the structure of the double-ion polymerization monomer can be adsorbed on the surface of clay particles through electrostatic adsorption, and the polyoxyethylene ether molecular chain can tightly coat the clay particles. In addition, the existence of sulfonic acid anions can not only improve the salt resistance of the resin, but also promote the resin to quickly form a coating film on the surface of the clay. The above various effects can make the prepared sulfonated phenolic aldehyde resin exhibit excellent temperature-resistant and salt-resistant fluid loss reduction performance.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil field drilling, and particularly relates to a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid and a preparation method thereof. BACKGROUND

[0002] Drilling fluid is a special fluid used in drilling engineering, and is called "the blood of drilling". Its core functions include cleaning the bottom of the well, cooling and lubricating the drilling tool, balancing the formation pressure, stabilizing the well wall, transmitting hydraulic power and protecting the oil and gas layer. In deep wells, ultra-deep wells and complex geological conditions, the performance of the drilling fluid directly determines the drilling efficiency, safety and oil and gas layer protection effect.

[0003] Phenolic resin, as one of the main filtrate reducers for drilling fluid, has been widely used in drilling operations since its advent. It has stable performance and good filtrate reduction effect, and plays an important role in deep wells with high temperature and high pressure. The sulfonated phenolic resin prepared by sulfonating modification of phenolic resin has good salt resistance. For example, the patent with the publication number CN116333697B discloses a method for preparing a filtrate reducer for drilling fluid by using modified lignite resin. The sulfonated phenolic resin is modified to give the drilling fluid more excellent comprehensive performance. However, the existing sulfonated phenolic resin mainly relies on van der Waals force to be adsorbed on the surface of clay particles, which leads to a small amount of adsorption on the surface of clay. As the downhole temperature rises, the sulfonated phenolic resin gradually becomes unstable and eventually separates from the surface of clay. Therefore, the existing sulfonated phenolic resin still has defects in practical application. SUMMARY

[0004] In view of the deficiencies of the prior art, the purpose of the present application is to provide a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid and a preparation method thereof.

[0005] In the first aspect of the present application, a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid is provided, which is prepared from the following raw materials in the amount of parts by weight:

[0006] phenolic resin 65-75 parts, functional modification reagent 10-20 parts, catalyst 1-3 parts, diionic polymerization monomer 15-30 parts, and initiator 0.1-0.2 parts.

[0007] As a preferred technical solution of the present application, the functional modification reagent is at least one of acryloyl chloride or methacryloyl chloride.

[0008] As a preferred technical solution of the present application, the catalyst is at least one of pyridine or triethylamine.

[0009] As a preferred technical solution of the present application, the preparation method of the diionic polymerization monomer comprises the following steps:

[0010] Step S1: Add allyl polyoxyethylene ether to tetrahydrofuran and stir until a homogeneous reaction solution is formed. Then, add sodium succinic anhydride-3-sulfonate to the reaction solution. After the addition is complete, turn on the heater and control the temperature at 40-50℃. Keep the temperature and stir for 2-6 hours. Then evaporate the solvent, collect the product, and purify it to obtain the intermediate.

[0011] Step S2: Add the intermediate and acetone to the reactor, start stirring, mix evenly, then purge with nitrogen for protection, and add the composite catalyst to the reactor. After addition, stir and mix at room temperature for 1-2 hours. Then continue to add 2-hydroxy-N,N,N-trimethylethylammonium chloride to the reactor. After addition, stir at 30-40℃ for 4-8 hours, evaporate to remove the solvent, and the product is purified to obtain the biionic polymer monomer.

[0012] As a preferred embodiment of the present invention, the allyl polyoxyethylene ether has a number-average molecular weight of 400.

[0013] As a preferred embodiment of the present invention, the molar ratio of allyl polyoxyethylene ether to sodium succinic anhydride-3-sulfonate is 1:1.

[0014] As a preferred embodiment of the present invention, the composite catalyst is a mixture of dicyclohexylcarbodiimide and 4-dimethylaminopyridine in a mass ratio of 1:0.3-0.4.

[0015] As a preferred embodiment of the present invention, the molar ratio of the intermediate to 2-hydroxy-N,N,N-trimethylethylammonium chloride is 1:1.

[0016] As a preferred embodiment of the present invention, the initiator is at least one of azobisisobutyronitrile or azobisisoheptanenitrile.

[0017] In the above technical solution, allyl polyoxyethylene ether and sodium succinic anhydride-3-sulfonate are first used as raw materials. The active hydroxyl substituents and anhydride groups in their structures can undergo ring-opening esterification reaction to obtain a polyoxyethylene ether derivative containing sulfonic acid groups and active carboxyl substituents, i.e., an intermediate. Then, under the action of a composite catalyst, the active carboxyl group of the intermediate can undergo esterification condensation with the hydroxyl group in the structure of 2-hydroxy-N,N,N-trimethylethylammonium chloride to obtain a polyoxyethylene ether derivative containing both sulfonic acid anions and quaternary ammonium salt cations, i.e., a biionic polymer monomer.

[0018] A method for preparing a temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluids includes the following steps:

[0019] The first step, phenolic resin is added to acetone, after adding, mechanical stirring is uniformly mixed, then under the condition of ice bath, functional modification reagent and catalyst are added to the formed mixed solution, after adding, the ice bath is removed, after stirring at the temperature of 30-40 DEG C for 2-4h, the solvent is evaporated, the product is collected, and the modified phenolic resin material is obtained;

[0020] The second step, the modified phenolic resin material and xylene are added to the polymerization kettle, nitrogen is introduced for protection, then, the diionic polymerization monomer and initiator are added to the polymerization kettle, heating is started, the temperature is increased to 70-90 DEG C, after heat preservation polymerization for 12-16h, heating is stopped, the product is separated, and the modified sulfonated phenolic resin is obtained after purification treatment.

[0021] In the above technical scheme, the functional modification reagent is used to modify the phenolic resin first, the phenolic resin containing unsaturated alkenyl functional groups in the structure is prepared, that is, the modified phenolic resin material, then, under the action of the initiator, the unsaturated alkenyl functional groups in the structure of the diionic polymerization monomer and the unsaturated alkenyl of the modified phenolic resin material occur free radical polymerization, and the modified sulfonated phenolic resin is prepared.

[0022] Compared with the prior art, the present application has the following beneficial effects:

[0023] The modified sulfonated phenolic resin is prepared by preparing the diionic polymerization monomer and polymerizing in situ with the phenolic resin, on the one hand, the existence of quaternary ammonium cations can improve the resin concentration around the negatively charged clay particles through electrostatic adsorption, then, through electrostatic adsorption, the resin is adsorbed on the surface of the clay particles, at the same time, the polyoxyethylene ether molecular chain in the structure of the resin has strong hydrophilicity, can tightly coat the clay particles with strong hydrophilicity, and then, through the dual combination effect of electrostatic force and van der waals force, the clay particles are firmly coated on the surface of the clay particles. On the other hand, the sulfonic acid anions in the structure of the resin can be complexed with metal salt ions, so that the resin can exhibit good salt resistance, and the existence of the sulfonic acid anions can promote the resin to form a coating film on the surface of the clay, so as to weaken flocculation and improve the stability of the colloid and the slurry. The above various effects can effectively prevent the contact between water and clay particles, so that the clay particles can maintain reasonable grading, and then form a dense mud cake, and exhibit excellent temperature resistance, salt resistance and filtration reduction performance. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed for the embodiment description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creating laborious work.

[0025] Figure 1 The infrared analysis test chart of the diionic polymerization monomer. DETAILED DESCRIPTION

[0026] For the purpose of understanding the present application, the present application is illustrated by the following examples. It should be apparent to those skilled in the art that the examples are merely illustrative of the present application and should not be viewed as limiting the present application.

[0027] Some components in the examples and comparative examples are as follows:

[0028] Example 1

[0029] The present example provides a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid, which is made of the following raw materials measured by weight fraction:

[0030] phenolic resin 65 parts, methacryloyl chloride 10 parts, pyridine 1 part, diionic polymerization monomer 15 parts, and azobisisobutyronitrile 0.1 part.

[0031] The preparation method of the modified sulfonated phenolic resin comprises the following steps:

[0032] In the first step, the phenolic resin is added to acetone, and after the addition is completed, the mixture is uniformly stirred mechanically, then the methacryloyl chloride and the pyridine are added to the formed mixed solution under ice bath condition, after the addition is completed, the ice bath is removed, and after stirring at a temperature of 35℃ for 3h, the solvent is evaporated to collect the product, obtaining the phenolic resin modified material;

[0033] In the second step, the phenolic resin modified material and dimethylbenzene are added to a polymerization kettle, and then the diionic polymerization monomer and azobisisobutyronitrile are added to the polymerization kettle, and heating is started to increase the temperature to 80℃, and after 16h of polymerization under constant temperature, the heating is stopped, and the product is separated and purified to obtain the modified sulfonated phenolic resin.

[0034] The diionic polymerization monomer is prepared by the following method:

[0035] In step S1, 1.2g of allyl polyoxyethylene ether with a number average molecular weight of 400 is added to tetrahydrofuran, and stirred to form a uniform reaction solution, then 0.6g of succinic anhydride-3-sulfonic acid sodium is added to the reaction solution, after the addition is completed, heating is started, and the temperature is controlled at 45℃, and after 4h of constant temperature stirring, the solvent is evaporated to collect the product, which is purified to obtain the intermediate.

[0036] Step S2, 0.9 g of intermediate and acetone were added to the reaction kettle, stirring was started, and after mixing, nitrogen was introduced for protection, and 0.1 g of dicyclohexyl carbodiimide and 0.04 g of 4-dimethylamino pyridine were added to the reaction kettle, after addition, stirring was started at room temperature for 1 h, then 0.2 g of 2-hydroxy-N,N,N-trimethyl ethyl ammonium chloride was added to the reaction kettle, after addition, stirring was started at 35°C for 6 h, the solvent was evaporated, and the product was purified to obtain the diionic polymerization monomer.

[0037] Figure 1 The infrared analysis test diagram of the diionic polymerization monomer is shown in the figure, and the characteristic absorption peak at 3340 cm -1 is attributed to the O-H characteristic absorption peak of the sulfonic acid group, the characteristic absorption peak at 3095 cm -1 is attributed to the C-H characteristic absorption peak of the unsaturated alkenyl functional group, the characteristic absorption peak at 1751 cm -1 is attributed to the C=O characteristic absorption peak of the ester group, the characteristic absorption peak at 1081 cm -1 is attributed to the C-O characteristic absorption peak of the ether bond.

[0038] Example 2

[0039] The embodiment provides a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid, which is prepared from the following raw materials in parts by weight:

[0040] phenolic resin 70 parts, methacryloyl chloride 15 parts, pyridine 2 parts, diionic polymerization monomer 25 parts, and azobisisobutyronitrile 0.2 parts.

[0041] The preparation method of the modified sulfonated phenolic resin comprises the following steps:

[0042] First step, the phenolic resin is added to acetone, after addition, mechanical stirring is started, and then methyl methacryloyl chloride and pyridine are added to the formed mixed solution under ice bath condition, after addition, the ice bath is removed, and stirring is started at 35°C for 3 h, then the solvent is evaporated, and the product is collected to obtain the phenolic resin modified material;

[0043] Second step, the phenolic resin modified material and xylene are added to the polymerization kettle, nitrogen is introduced for protection, then the diionic polymerization monomer and azobisisobutyronitrile are added to the polymerization kettle, heating is started, the temperature is increased to 80°C, and after 16 h of incubation and polymerization, heating is stopped, the product is separated, and purification treatment is performed to obtain the modified sulfonated phenolic resin.

[0044] The preparation method of the diionic polymerization monomer is shown in Example 1.

[0045] Example 3

[0046] The embodiment provides a temperature-resistant and salt-resistant modified sulfonated phenolic resin for drilling fluid, which is prepared from the following raw materials in the amount of parts by weight:

[0047] phenolic resin 75 parts, methacryloyl chloride 20 parts, pyridine 3 parts, double-ion polymerization monomer 30 parts, and azobisisobutyronitrile 0.2 parts.

[0048] The preparation method of the modified sulfonated phenolic resin comprises the following steps:

[0049] In the first step, the phenolic resin is added to acetone, and after the addition, the mixture is uniformly stirred mechanically, then the methacryloyl chloride and pyridine are added to the formed mixed solution under ice bath conditions, after the addition, the ice bath is removed, and after stirring at a temperature of 35 DEG C for 3 h, the solvent is evaporated to collect the product, and the modified phenolic resin is obtained.

[0050] In the second step, the modified phenolic resin and dimethylbenzene are added to a polymerization kettle, and nitrogen is introduced for protection, then the double-ion polymerization monomer and azobisisobutyronitrile are added to the polymerization kettle, heating is started, the temperature is increased to 80 DEG C, and after 16 h of temperature maintaining polymerization, the heating is stopped, and the product is separated and purified to obtain the modified sulfonated phenolic resin.

[0051] The preparation method of the double-ion polymerization monomer is shown in Embodiment 1.

[0052] Comparative Example 1

[0053] The difference between the comparative example and Embodiment 2 is that the double-ion polymerization monomer intermediate is replaced by intermediate, and the rest is the same.

[0054] The preparation method of the intermediate is shown in Embodiment 1.

[0055] The modified sulfonated phenolic resin provided in the above embodiments and comparative examples is subjected to performance testing, and the testing method is as follows:

[0056] In 350 mL of deionized water, 0.5 g of anhydrous sodium carbonate and 6.8 g of bentonite are added and mechanically stirred, and after 25 DEG C curing for one day, 10 g of sulfonated lignite and 10.5 g of the modified sulfonated phenolic resin are continuously added, and after mechanical stirring, 110 g of sodium chloride is added, and after stirring until completely dissolved, 25 DEG C curing is carried out for 3 h, and then 16 h of hot rolling is carried out at a temperature of 220 DEG C, and then the product is taken out and naturally cooled completely, and then 6 g of anhydrous sodium carbonate is continuously added and stirred to obtain a high-salt drilling fluid sample. According to the standard GB / T 16783.1-2014, the filtration loss is tested under the conditions of 25 DEG C, 0.7 MPa and 180 DEG C, 3.5 MPa, and the filtration loss under the conditions of normal temperature and pressure and high temperature and pressure is recorded.

[0057] The performance test data are shown in Table 1.

[0058] Table 1 - Performance test results

[0059]

[0060] The commercially available sulfonated phenolic resin is SMP-Ⅱ type sulfonated phenolic resin.

[0061] From the above, the modified sulfonated phenolic resin prepared in the embodiments of the present application can exhibit excellent fluid loss reduction performance in high salt solution, and the high temperature resistance is also relatively excellent. After replacing the di-ionic polymer monomer intermediate with the intermediate, the modified sulfonated phenolic resin prepared does not contain quaternary ammonium cations in the structure, so the adsorption effect on clay particles is relatively poor, and the fluid loss reduction performance is seriously decreased, which simultaneously affects the filter cake stability, resulting in the high temperature resistance being affected.

[0062] The principles and implementations of the present application are described in the specific examples in this paper, and the above examples are only used to help understand the method of the present application and its core idea, including the best mode, and also enable any person skilled in the art to practice the present application, including manufacturing and using any device or system, and implementing any combined method. It should be noted that for those skilled in the art, without departing from the principles of the present application, some improvements and modifications can be made to the present application, and these improvements and modifications also fall within the scope of protection of the present application.

Claims

1. A temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluids, characterized in that, It is made from the following raw materials, measured in parts by weight: The composition includes 65-75 parts phenolic resin, 10-20 parts functionalizing modifier, 1-3 parts catalyst, 15-30 parts biionic polymerization monomer, and 0.1-0.2 parts initiator. The functionalizing agent is at least one of acryloyl chloride or methacryloyl chloride; The catalyst is at least one of pyridine or triethylamine; The preparation method of the dual-ion polymerizable monomer includes the following steps: Step S1: Add allyl polyoxyethylene ether to tetrahydrofuran and stir until a homogeneous reaction solution is formed. Then, add sodium succinic anhydride-3-sulfonate to the reaction solution. After the addition is complete, turn on the heater and control the temperature at 40-50℃. Keep the temperature and stir for 2-6 hours. Then evaporate the solvent, collect the product, and purify it to obtain the intermediate. Step S2: Add the intermediate and acetone to the reactor, start stirring, mix evenly, then purge with nitrogen for protection, and add the composite catalyst to the reactor. After addition, stir and mix at room temperature for 1-2 hours. Then continue to add 2-hydroxy-N,N,N-trimethylethylammonium chloride to the reactor. After addition, stir at 30-40℃ for 4-8 hours, evaporate to remove the solvent, and the product is purified to obtain the biionic polymer monomer. The initiator is at least one of azobisisobutyronitrile or azobisisoheptanenitrile; The composite catalyst is a mixture of dicyclohexylcarbodiimide and 4-dimethylaminopyridine in a mass ratio of 1:0.3-0.

4.

2. The temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluid according to claim 1, characterized in that, The number average molecular weight of the allyl polyoxyethylene ether is 400.

3. The temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluid according to claim 1, characterized in that, The molar ratio of the allyl polyoxyethylene ether to sodium succinic anhydride-3-sulfonate is 1:

1.

4. The temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluid according to claim 1, characterized in that, The molar ratio of the intermediate to 2-hydroxy-N,N,N-trimethylethylammonium chloride is 1:

1.

5. A method for preparing the temperature- and salt-resistant modified sulfonated phenolic resin for drilling fluid as described in claim 1, characterized in that, Includes the following steps: Step 1: Add phenolic resin to acetone. After addition, mechanically stir to mix evenly. Then, under ice bath conditions, add functionalizing agent and catalyst to the formed mixed solution. After addition, remove from ice bath and stir at 30-40℃ for 2-4 hours. Evaporate to remove solvent and collect product to obtain phenolic resin modified material. The second step involves adding the phenolic resin modifier and xylene to the polymerization reactor, purging with nitrogen for protection, then adding the biionic polymerization monomer and initiator to the polymerization reactor, turning on the heater, raising the temperature to 70-90℃, maintaining the temperature for 12-16 hours, stopping the heating, separating the product, and purifying it to obtain the modified sulfonated phenolic resin.

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