A wetting type clay stabilizer and a method for preparing the same

Abstract

The present application belongs to the technical field of oilfield clay anti-swelling, and provides a preparation method of a clay stabilizer containing both cationic inhibiting groups and hydrophilic groups in the molecular structure, characterized in that the clay stabilizer is prepared by reacting hydroxy acid with 3-chloro-2-hydroxypropyl trimethyl ammonium chloride in a solvent under the action of an alkalizing agent and then with sorbitol, has good anti-swelling effect and outstanding hydrophilic property. The clay stabilizer has an anti-swelling rate of greater than 80% at room temperature, and the contact angle between the treated clay particles and water is kept below 40°, and can be used for inhibiting the hydration and swelling of formation clay minerals and protecting the pore hydrophilicity in the process of water injection into oil wells.

Description

TECHNICAL FIELD

[0001] The present application relates to a preparation method of a wet clay stabilizer, and belongs to the technical field of oil field additives. BACKGROUND

[0002] The clay minerals mainly include kaolinite, illite, montmorillonite and chlorite, and are common mineral components in the formation.

[0003] Among them, montmorillonite is a strong water-sensitive clay mineral. Experiments show that the permeability of a core with a clay mineral content of about 20% is only about 3% of the initial permeability after water invasion, so a certain concentration of clay stabilizer is often added during conventional water injection production or fracturing to inhibit the hydration and swelling of the water-sensitive clay minerals in the formation, so as to protect the permeability of the formation.

[0004] Early clay stabilizers mainly include inorganic salts such as potassium chloride, ammonium chloride and potassium formate. Due to the influence of high-concentration salts on benthic organisms, inorganic polynuclear polymers, cationic surfactants and cationic organic polymers have gradually replaced them. Such clay stabilizers often contain adsorption sites such as -NH2, -NH3 + , -N + R4, etc. in the molecular structure, which can be adsorbed with electronegative clay particles to inhibit the hydration and swelling process of the clay particles. Long-term practice shows that end-cation clay stabilizers such as benzyltrimethylammonium chloride often contain hydrophobic groups such as benzene rings and hydrocarbon groups in their molecular structures. When such clay stabilizers containing hydrophobic groups are used in large quantities, they are easily enriched and adsorbed on the surface of the formation pore, reducing the hydrophilicity of the formation pore, so that the injection water containing oil displacement agents cannot enter the formation pore, resulting in a decrease in the effect of water injection and oil displacement in the oil well. Therefore, in the design and synthesis of new clay stabilizers, not only the anti-swelling performance of the clay stabilizer should be considered, but also the new problems caused by the enrichment of the clay stabilizer in the formation should be considered. SUMMARY

[0005] The purpose of the present application is to solve the above problems, and a wet clay stabilizer and a preparation method thereof are provided.

[0006] The wet clay stabilizer provided by the present application has the following characteristics in the molecular structure:

[0007]

[0008] Formula (1)

[0009] wherein R is C6H 13 O6;

[0010] or

[0011]

[0012] Formula (2)

[0013] wherein R1, R2 are C6H 13 O6 or K + , Na + , and R1, R2 are not K + or Na + at the same time; R3, R4 are C6H 15 ClNO or H, and R3, R4 are not H at the same time;

[0014] or

[0015]

[0016] Formula (3)

[0017] wherein R1, R2 are C6H 13 O6 or K + , Na + , and R1, R2 are not K + or Na + at the same time;

[0018] or

[0019]

[0020] Formula (4)

[0021] wherein R1, R2, R3 are C6H 13 O6 or K + , Na + , and R1, R2, R3 are not K + or Na + at the same time.

[0022] In the present application, the sorbitol molecule is C6H 14 O6, and its structural formula is shown in Formula (5), and the molecule contains 6 hydroxyl groups. The C6H 13 O6 is the remaining group after removing one hydroxyl hydrogen from sorbitol, and since the 6 hydroxyl groups in the sorbitol molecule all have esterification reactivity, the C6H 13 O6 in the present application can be the dehydrogenation product of any one of the hydroxyl groups of sorbitol.

[0023]

[0024] Formula (5).

[0025] In the present application, the C6H 15 ClNO structure is shown in Formula (6), wherein * indicates that the group is connected to the substituent group.

[0026]

[0027] Formula (6).

[0028] The present application also provides a preparation method of the wetting type clay stabilizer, characterized in that a hydroxyl acid is cationically etherified and the product is further esterified with a polyhydroxyl sorbitol to synthesize the wetting type clay stabilizer with good anti-swelling effect and high hydrophilicity.

[0029] Further, the preparation method of the clay stabilizer comprises the following steps:

[0030] (1) dissolving the hydroxyl acid in a solvent and adding an alkalizing agent for reaction;

[0031] (2) adding 3-chloro-2-hydroxypropyl trimethyl ammonium chloride into the above system for reaction;

[0032] (3) after cooling, acid neutralization and impurity removal by vacuum distillation, the product of step (2) is prepared into an intermediate product;

[0033] (4) the sorbitol is reacted with the intermediate product under the action of an acid catalyst, and the product is finally prepared into the clay stabilizer after neutralization, filtration and impurity removal by vacuum distillation.

[0034] Further, the hydroxyl acid can be one of lactic acid, tartaric acid, malic acid and citric acid.

[0035] Further, the solvent can be one of water and N,N-dimethylformamide.

[0036] Further, the alkalizing agent can be one of NaOH and KOH.

[0037] Further, the mass ratio of the hydroxyl acid to the alkalizing agent is 1:2.0-5.0.

[0038] Further, the mass ratio of the hydroxyl acid to 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is 1:1.0-2.5.

[0039] Further, the reaction temperature of step (2) ranges from 70 to 110 DEG C.

[0040] Further, the mass ratio of the hydroxyl acid to the sorbitol is 1:1.2-3.5.

[0041] The present application has the following effects:

[0042] The hydroxyl acid with hydrophilic groups such as hydroxyl group and carboxyl group in the molecular structure is cationic etherized, and the intermediate product is further esterized with sorbitol with multiple hydroxyl groups to obtain the clay stabilizer containing both cationic inhibiting groups and hydrophilic groups. The clay stabilizer can inhibit the hydration and expansion of clay and better retain the hydrophilicity of clay particles, which has very positive significance for protecting the formation permeability and improving the effect of oil well water injection mining. Embodiment

[0043] The application will be described in detail below in combination with examples. Example 1

[0044] 0.1 mol of malic acid is weighed into a flask, 50 g of water is added, and after the malic acid is completely dissolved under stirring, 0.4 mol of NaOH is added to react at 20℃ for 1 hour; then 0.12 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is added to the flask, and the temperature is raised to 85℃ to continue the reaction for 3 hours. After the reaction is completed, a small amount of hydrochloric acid is added to adjust the product to be neutral, and the solvent and excess reactants in the system are removed by distillation under reduced pressure to obtain the intermediate product. 0.2 mol of sorbitol is continuously added to the flask, and the temperature is raised to 95℃ to fully stir, and after the mixture is uniformly mixed, 5 mL of concentrated sulfuric acid is added dropwise to continue the reaction for 6 hours. After the reaction is completed, a small amount of alkali is added to adjust the product to be neutral, and after the impurities are removed by distillation under reduced pressure, the clay stabilizer is finally obtained. Example 2

[0045] 0.1 mol of malic acid is weighed into a flask, 50 g of water is added, and after the malic acid is completely dissolved under stirring, 0.3 mol of NaOH is added to react at 20℃ for 1 hour; then 0.2 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is added to the flask, and the temperature is raised to 110℃ to continue the reaction for 3 hours. After the reaction is completed, a small amount of hydrochloric acid is added to adjust the product to be neutral, and the solvent and excess reactants in the system are removed by distillation under reduced pressure to obtain the intermediate product. 0.2 mol of sorbitol is continuously added to the flask, and the temperature is raised to 95℃ to fully stir, and after the mixture is uniformly mixed, 5 mL of concentrated sulfuric acid is added dropwise to continue the reaction for 6 hours. After the reaction is completed, a small amount of alkali is added to adjust the product to be neutral, and after the impurities are removed by distillation under reduced pressure, the clay stabilizer is finally obtained. Example 3

[0046] Take 0.1 mol tartaric acid in a flask and add 50 g of N, N- dimethylformamide, after the tartaric acid is completely dissolved under stirring, add 0.4 mol NaOH at 20 °C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and warm to 70 °C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.2 mol of sorbitol to the flask and warm to 105 °C with sufficient stirring, after the mixture is uniform, drop 5 mL of concentrated sulfuric acid and continue to react for 6 h, after the reaction is completed, add a little alkali liquor to adjust the product to neutral, after removing the impurities by distillation under reduced pressure, finally the clay stabilizer is prepared. Example 4

[0047] Take 0.1 mol tartaric acid in a flask and add 50 g of N, N- dimethylformamide, after the tartaric acid is completely dissolved under stirring, add 0.4 mol NaOH at 20 °C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and warm to 70 °C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.2 mol of sorbitol to the flask and warm to 105 °C with sufficient stirring, after the mixture is uniform, drop 5 mL of concentrated sulfuric acid and continue to react for 6 h, after the reaction is completed, add a little alkali liquor to adjust the product to neutral, after removing the impurities by distillation under reduced pressure, finally the clay stabilizer is prepared. Example 5

[0048] Take 0.1 mol tartaric acid in a flask and add 50 g of N, N- dimethylformamide, after the tartaric acid is completely dissolved under stirring, add 0.4 mol NaOH at 20 °C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and warm to 70 °C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.2 mol of sorbitol to the flask and warm to 105 °C with sufficient stirring, after the mixture is uniform, drop 5 mL of concentrated sulfuric acid and continue to react for 6 h, after the reaction is completed, add a little alkali liquor to adjust the product to neutral, after removing the impurities by distillation under reduced pressure, finally the clay stabilizer is prepared. Example 6

[0049] Take 0.1 mol of lactic acid in a flask and add 50 g of water, after the citric acid is completely dissolved, add 0.2 mol of NaOH under stirring at 20°C for 1 hour; then add 0.15 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 85°C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C for sufficient stirring, then drop 5 mL of concentrated sulfuric acid into the mixture and continue to react for 6 hours. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by distillation under reduced pressure. Example 7

[0050] Take 0.1 mol of lactic acid in a flask and add 50 g of water, after the citric acid is completely dissolved, add 0.2 mol of NaOH under stirring at 20°C for 1 hour; then add 0.15 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 85°C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C for sufficient stirring, then drop 5 mL of concentrated sulfuric acid into the mixture and continue to react for 6 hours. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by distillation under reduced pressure. Example 8

[0051] Take 0.1 mol of lactic acid in a flask and add 50 g of water, after the citric acid is completely dissolved, add 0.2 mol of NaOH under stirring at 20°C for 1 hour; then add 0.15 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 85°C for 3 hours of continuous reaction. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by distillation under reduced pressure to prepare the intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C for sufficient stirring, then drop 5 mL of concentrated sulfuric acid into the mixture and continue to react for 6 hours. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by distillation under reduced pressure.

[0052] Comparative Example 1

[0053] Take 0.1 mol of tartaric acid in a flask and add 50 g of water, stir until the tartaric acid is completely dissolved, then add 0.5 mol of NaOH at 20°C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 90°C for 3 hours. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by vacuum distillation to prepare an intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C with stirring, then add 5 mL of concentrated sulfuric acid dropwise and continue to react for 6 h. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by vacuum distillation.

[0054] Comparative Example 2

[0055] Take 0.1 mol of tartaric acid in a flask and add 50 g of water, stir until the tartaric acid is completely dissolved, then add 0.5 mol of NaOH at 20°C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 90°C for 3 hours. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by vacuum distillation to prepare an intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C with stirring, then add 5 mL of concentrated sulfuric acid dropwise and continue to react for 6 h. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by vacuum distillation.

[0056] Comparative Example 3

[0057] Take 0.1 mol of tartaric acid in a flask and add 50 g of water, stir until the tartaric acid is completely dissolved, then add 0.5 mol of NaOH at 20°C for 1 hour; then add 0.1 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and heat to 90°C for 3 hours. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by vacuum distillation to prepare an intermediate product. Continue to add 0.12 mol of sorbitol to the flask and heat to 95°C with stirring, then add 5 mL of concentrated sulfuric acid dropwise and continue to react for 6 h. After the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing the impurities by vacuum distillation.

[0058] Comparative Example 4

[0059] Take 0.1 mol malic acid in a flask and add 50 g water to it, after the malic acid is completely dissolved, add 0.4 mol NaOH under stirring, react at 20℃ for 1 hour; then add 0.12 mol of 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the flask and continue to react at 85℃ for 3 hours. After the reaction is completed, add a little hydrochloric acid to adjust the product to neutral, and remove the solvent and excess reactants in the system by reduced pressure distillation to prepare the intermediate product. Continue to add 0.2 mol of glycerol to the flask and heat to 95℃, stir well, then drop 5 mL of concentrated sulfuric acid and continue to react for 6 h, after the reaction is completed, add a little alkali to adjust the product to neutral, and finally prepare the clay stabilizer after removing impurities by reduced pressure distillation.

[0060] Test Example 1

[0061] The anti-swelling performance test procedure of the clay stabilizer is as follows:

[0062] According to the performance evaluation method of clay stabilizer for water injection (SY / T5971-2016), the anti-swelling rate test is carried out, the procedure is as follows: take 0.5 g of sodium bentonite, add it into a 10 mL centrifuge tube, add deionized water to 10 mL scale, shake well, stand at room temperature for 2 h, load into a centrifuge, centrifuge at 1500 r / min for 15 min, read the volume of sodium bentonite in water V2. Using the same procedure, replace the water with a 2wt% clay stabilizer aqueous solution, measure the volume of the soil after centrifugation V1. Replace water with kerosene to measure the volume of the soil V0.

[0063]

[0064] In the formula: η—anti-swelling rate, %; V0—volume of sodium bentonite in kerosene, mL; V1—volume of sodium bentonite in clay stabilizer, mL; V2—volume of sodium bentonite in water, mL.

[0065] Test Example 2

[0066] The procedure for testing the hydrophilicity of clay particles is as follows:

[0067] Prepare 1000 mL of 10wt% test clay stabilizer aqueous solution, add 40 g of bentonite to it and stir for 24 h or more;

[0068] After step 1 is completed, perform suction filtration and dry the bentonite particles obtained by suction filtration at room temperature;

[0069] Take 20 g of the bentonite particles obtained by drying in step (2) and press them under a pressure of 10 MPa;

[0070] Use a contact angle measuring instrument to measure the contact angle between deionized water and the pressed tablets prepared in step (3).

[0071] Note: The contact angle of the original soil particles with water was measured directly from the tablet of the untreated original soil particles.

[0072] The samples prepared in Example 1-8 and Comparative Example 1-4 were evaluated according to the evaluation method in Test Example 1-2, and the evaluation results are shown in Table 1.

[0073] Table 1 Performance evaluation test of clay stabilizer

[0074]

[0075] As can be seen from the above examples and comparative examples, the hydrophilicity of the original soil particles without any treatment is good, and the contact angle with water is only 31.7°. The hydrophilicity of the clay particles treated with a general cationic clay stabilizer such as benzyltrimethylammonium chloride decreases significantly, and the contact angle with water reaches 104.2°. The anti-swelling performance of the clay stabilizer prepared in the present application is excellent, the hydrophilicity protection effect of the clay particles is obvious, the contact angle is maintained below 40°, and the application prospect is good.

Claims

1. A wetted type clay stabilizer, characterized by It has the following characteristics: Formula (1) wherein R is the residue of sorbitol C6H 13 O6 after dehydrogenation of any one of the hydroxyl groups; Or Formula (2) wherein R1, R2 are a residue of dehydrogenation of any one of the hydroxyl groups of sorbitol C6H 13 O6 or O - Na + , O - K + , and R1, R2 are not simultaneously O - Na + , O - K + ; R3, R4 are C6H 15 ClNO or H, and R3, R4 are not simultaneously H; The C6H 15 The structure of ClNO is as follows: Formula (6) Wherein * indicates the group is connected to the substituent; Or Formula (3) wherein R1, R2 are a residue of dehydrogenation of any one of the hydroxyl groups of sorbitol C6H 13 O6 or O - Na + , O - K + , and R1, R2 are not simultaneously O - Na + , O - K + ; Or Formula (4) wherein R1, R2, R3 are independently selected from the group consisting of a residue of sorbitol C6H 13 O6 dehydrogenated from any one of the hydroxyl groups or O - Na + , O - K + one of Na, K, and R1, R2, R3 are not simultaneously O - Na + , O - K + .

2. A method for producing the wetting type clay stabilizer according to claim 1, characterized by The hydroxy acid is cationically etherified and the product is further esterified with polyhydroxyl sorbitol to synthesize the wetting clay stabilizer.

3. The method of claim 2, wherein the wetting-type clay stabilizer is prepared by The preparation process comprises the following steps: (1) Dissolve the hydroxy acid in a solvent and add a basifying agent for reaction; (2) Add 3-chloro-2-hydroxypropyl trimethyl ammonium chloride to the above system for reaction; (3) After cooling, acid neutralization and impurity removal by vacuum distillation, the product of step (2) is obtained as an intermediate product; (4) React sorbitol with the intermediate product in the presence of an acid catalyst, and the product is obtained after neutralization, filtration and impurity removal by vacuum distillation to obtain the clay stabilizer.

4. The method of claim 3, wherein the wet-type clay stabilizer is prepared by adding the clay stabilizer to the water, and then adding the dispersant to the mixture of the clay stabilizer and the water. The hydroxy acid is selected from one of lactic acid, tartaric acid, malic acid and citric acid.

5. The method for preparing the wetting clay stabilizer according to claim 3, characterized in that... The solvent is selected from one of water and N,N-dimethylformamide.

6. The method for preparing the wetting clay stabilizer according to claim 3, characterized in that... The basifying agent is selected from one of NaOH and KOH.

7. The method for preparing the wetting clay stabilizer according to claim 3, characterized in that... The molar ratio of the hydroxy acid to the basifying agent is 1:2.0-5.

0.

8. The method for preparing the wetting clay stabilizer according to claim 3, characterized in that... The molar ratio of the hydroxy acid to 3-chloro-2-hydroxypropyl trimethyl ammonium chloride is 1:1.0-2.

5.

9. The preparation method of the wetting clay stabilizer according to claim 3, wherein the reaction temperature of step (2) is in the range of 70-110℃.

10. The method for preparing the wetting clay stabilizer according to claim 3, characterized in that... The molar ratio of the hydroxy acid to sorbitol is 1:1.2-3.5.

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