Cationic self-assembly high-temperature-resistant clay stabilizer and preparation method thereof

Abstract

The invention discloses a cationic self-assembly high-temperature-resistant clay stabilizer and a preparation method thereof.The preparation method sequentially comprises the following steps that firstly, N-methylbenzylamine, diethylenetriamine and epichlorohydrin are subjected to a substitution reaction, and polyquaternary ammonium containing quaternary ammonium ions and benzyl is prepared; then carrying out a reaction on the mono6-amino-beta-cyclodextrin and epoxy chloropropane, so as to prepare a beta-cyclodextrin-epoxy chloropropane condensation compound; and finally, blending and assembling the two substances to generate the cation assembled compound with relatively high cation degree and high temperature resistance. Polyquaternary ammonium containing quaternary ammonium ions and benzyl in the cation assembly compound provides quaternary ammonium cations combined with anionic charges on the surface of stratum clay minerals on one hand, and provides benzene rings combined with beta-CD holes of the beta-cyclodextrin-epichlorohydrin condensation compound on the other hand. The prepared clay stabilizer has good high temperature resistance, has a good clay anti-swelling effect under a strong alkaline condition, and can improve the crude oil recovery rate.

Description

Technical Field

[0001] The invention relates to a clay stabilizer, in particular to a cationic self-assembled high temperature resistant clay stabilizer. The invention also relates to a preparation method of the cationic self-assembled high temperature resistant clay stabilizer, and belongs to the technical field of oilfield production additives. Background Art

[0002] China has abundant heavy oil resources, which are characterized by high viscosity and difficulty in flowing. Most of them are produced by steam injection. Although steam injection can increase production by increasing the fluidity of crude oil, the injection of high-temperature and strong alkaline steam causes certain damage to the oil layer. The high temperature and strong alkaline environment in steam injection operations will cause clay expansion and mineral dissolution. At the same time, the high-speed injection of high-temperature steam will also cause particle migration, which will eventually cause a significant decrease in reservoir permeability and affect the effective development of crude oil.

[0003] At present, clay stabilizers mainly include ammonium chloride, potassium chloride, tetramethylammonium chloride, polyquaternary amine and other inorganic salts or organic compounds that can ionize cations in aqueous solution. Among them, polyquaternary amine is the most commonly used. Due to the limited cationicity of these compounds and the strong water sensitivity of clay, the electrostatic interaction between anions and cations of these compound molecules on the surface of clay minerals cannot completely prevent the infiltration of water molecules, which leads to the expansion and dispersion of the core. Especially in the process of steam injection, on the one hand, the high formation temperature leads to the high-temperature decomposition of ordinary clay stabilizers. On the other hand, the content of inorganic metal ions in the distilled water generated by steam condensation is extremely low, which makes it easier to cause clay minerals to absorb water and expand. The anti-swelling efficiency of conventional clay stabilizers is low. Therefore, the development of a clay stabilizer with strong temperature resistance and good anti-swelling effect is urgently needed for heavy oil steam injection thermal recovery. Summary of the invention

[0004] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract of the specification of this application and the title of the invention, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0005] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0006] The primary purpose of the present invention is to overcome the problems existing in the prior art and provide a method for preparing a cationic self-assembled high-temperature resistant clay stabilizer. The prepared clay stabilizer has good high-temperature resistance and good clay anti-swelling effect under strong alkaline conditions, which can improve crude oil recovery.

[0007] In order to solve the above technical problems, the preparation method of a cationic self-assembled high temperature resistant clay stabilizer of the present invention comprises the following steps in sequence: firstly, N-methylbenzylamine, diethylenetriamine and epichlorohydrin are subjected to substitution reaction to prepare polyquaternary ammonium containing quaternary ammonium ions and benzyl groups; then, mono-6-amino-β-cyclodextrin is reacted with epichlorohydrin to prepare β-cyclodextrin-epichlorohydrin condensate; finally, the above two substances are blended and assembled to generate a cationic assembly complex with high cationic degree and strong temperature resistance.

[0008] Furthermore, the polyquaternary ammonium containing quaternary ammonium ions and benzyl groups in the cationic assembly complex provides quaternary ammonium cations that combine with the anionic charges on the surface of the formation clay mineral on the one hand, and provides benzene rings that combine with the β-CD holes of the β-cyclodextrin-epichlorohydrin condensate on the other hand.

[0009] Further, the raw materials include N-methylbenzylamine, diethylenetriamine, epichlorohydrin and mono-6-amino-β-cyclodextrin, and the following steps are sequentially included:

[0010] S1, take 12.0g N-methylbenzylamine and add it to 70ml distilled water, heat it to 60℃, stir and dissolve, introduce nitrogen, slowly add 9.5g epichlorohydrin dropwise, control the dropping speed, keep the reaction temperature at 60℃, need 2 hours, then continue to keep the reaction temperature for 3 hours, cool it to room temperature, generate a light yellow viscous transparent liquid, set aside;

[0011] S2, take 1.0g of diethylenetriamine and add it to 70ml of distilled water, cool it to 10°C, slowly add 3.7g of epichlorohydrin, control the dropping speed, keep the reaction temperature below 10°C, take 1 hour, after the dropping is completed, warm it to room temperature to generate a light yellow transparent liquid, set aside;

[0012] S3, the light yellow viscous transparent liquid generated in the above S1 is fully mixed with the light yellow liquid generated in the above S2, the temperature is raised to 70°C, stirred for reaction for 3 hours, and the temperature is lowered to room temperature to generate a yellow viscous transparent liquid, which is set aside;

[0013] S4, dissolve 8.5g of mono-6-amino-β-cyclodextrin and 0.5g of sodium hydroxide in 50ml of distilled water, heat to 40°C, introduce nitrogen, then add 2.3g of epichlorohydrin in batches under stirring for 2 hours, and keep warm for 3 hours after the addition to obtain a light yellow viscous liquid for standby use;

[0014] S5. Fully mix the light yellow viscous transparent liquid produced in S3 and the light yellow viscous liquid produced in S4, and perform ultrasonic oscillation to obtain a yellow viscous transparent liquid.

[0015] Further, the reaction formula of step S1 is as follows:

[0016]

[0017] Further, the reaction formula of step S2 is as follows:

[0018]

[0019] Further, the reaction formula of step S3 is as follows:

[0020]

[0021] Further, the reaction formula of step S4 is as follows:

[0022]

[0023] Another object of the present invention is to overcome the problems existing in the prior art and provide a cationic self-assembled high temperature resistant clay stabilizer, which has good high temperature resistance and good clay anti-swelling effect under strong alkaline conditions, thereby improving crude oil recovery.

[0024] In order to solve the above technical problems, the cationic self-assembled high temperature resistant clay stabilizer of the present invention is prepared by any one of the above methods.

[0025] Compared with the prior art, the present invention has achieved the following beneficial effects: 1. The cationic self-assembled composite clay anti-swelling agent prepared by the present invention with N-methylbenzylamine, diethylenetriamine, epichlorohydrin and mono-6-amino-β-cyclodextrin as main raw materials has good high temperature resistance and good clay anti-swelling effect under strong alkaline conditions.

[0026] 2. The multiple benzyl groups of the polyquaternary ammonium containing quaternary ammonium ions and benzyl groups are included in the hydrophobic cavity by the β-cyclodextrin of the β-cyclodextrin-epichlorohydrin copolymer, which improves the high temperature resistance and alkali resistance of the polyquaternary ammonium. The resulting composite has a good clay anti-swelling effect under high temperature and strong alkaline conditions, preventing the reduction of crude oil recovery rate due to clay expansion in heavy oil steam injection thermal recovery.

[0027] 3. The polyquaternary ammonium molecules in the complex play a role in stabilizing clay, and the β-cyclodextrin-epichlorohydrin condensate molecules cover the outside of the polyquaternary ammonium molecules, protecting the polyquaternary ammonium molecules, thereby enhancing the thermal stability of the polyquaternary ammonium molecules and the high-temperature anti-swelling ability of clay minerals. The present invention provides a new way to prepare a high-temperature resistant clay stabilizer. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects of the present invention easy to understand, it is obvious that the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.

[0029] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art of the present invention. The terms used in the specification of the present invention herein are only for the purpose of describing specific embodiments and are not intended to limit the present invention.

[0030] Example 1

[0031] S1, take 12.0g N-methylbenzylamine and add it to 70ml distilled water, heat it to 60℃, stir and dissolve, introduce nitrogen, slowly add 9.5g epichlorohydrin dropwise, control the dropping speed, keep the reaction temperature at 60℃, need 2 hours, then continue to keep the reaction temperature for 3 hours, cool it to room temperature, generate a light yellow viscous transparent liquid, set aside;

[0032] S2, take 1.0g of diethylenetriamine and add it to 70ml of distilled water, cool it to 10°C, slowly add 3.7g of epichlorohydrin, control the dropping speed, keep the reaction temperature below 10°C, take 1 hour, after the dropping is completed, warm it to room temperature to generate a light yellow transparent liquid, set aside;

[0033] S3, the light yellow viscous transparent liquid generated in the above S1 is fully mixed with the light yellow liquid generated in the above S2, the temperature is raised to 70°C, stirred for reaction for 3 hours, and the temperature is lowered to room temperature to generate a yellow viscous transparent liquid, which is set aside;

[0034] S4, dissolve 8.5g of mono-6-amino-β-cyclodextrin and 0.5g of sodium hydroxide in 50ml of distilled water, heat to 40°C, introduce nitrogen, then add 2.3g of epichlorohydrin in batches under stirring for 2 hours, and keep warm for 3 hours after the addition to obtain a light yellow viscous liquid for standby use;

[0035] S5. Fully mix the light yellow viscous transparent liquid produced in S3 and the light yellow viscous liquid produced in S4, and perform ultrasonic oscillation to obtain a yellow viscous transparent liquid.

[0036] Example 2

[0037] A certain amount of the yellow viscous transparent liquid obtained in S3 of Example 1 was weighed to prepare pharmaceutical solutions with concentrations of 0.3%, 0.5%, 0.7% and 1.0%, respectively, and the pH value of the pharmaceutical solution was adjusted to 12 with 5% sodium hydroxide; 0.50 g of sodium montmorillonite was accurately weighed, put into a 10 mL centrifuge tube, 5 mL of kerosene was added, ultrasonic oscillation was performed evenly, and after standing for 12 hours, the tube was put into a centrifuge and centrifuged at a speed of 1500 r / min for 10 minutes, and the original volume of the montmorillonite was read; 0.50 g of sodium montmorillonite was accurately weighed, put into a 10 mL centrifuge tube, 5 mL of kerosene was added, ultrasonic oscillation was performed evenly, and the tube was placed in a centrifuge for 12 hours, ... .50g sodium montmorillonite was placed in a sealed jar, and 10mL of distilled water and the above-mentioned reagent solutions of different concentrations were added respectively. The mixture was shaken evenly and placed in a muffle furnace at 200℃ for 24 hours. The mixture was naturally cooled to room temperature, and the clay and solution in the sealed jar were transferred to a centrifuge tube. The mixture was centrifuged at 1500r / min for 10 minutes. The volume of the montmorillonite after being treated with the reagent was read and the anti-swelling rate of the reagent was calculated. The anti-swelling rate of the reagent on sodium montmorillonite at 250℃ and 300℃ was determined by the same method as above. The results are shown in Table 1.

[0038] Table 1 Anti-swelling ability of different concentrations of agents on sodium montmorillonite

[0039]

[0040]

[0041] Example 3

[0042] 0.50 g of sodium montmorillonite was accurately weighed and placed in a sealed can. The reagent solution prepared in Example 2 with different concentrations was added and shaken evenly. The mixture was placed in a muffle furnace at 300° C. and heated for 24 hours. The mixture was naturally cooled to room temperature. The reagent solution in the centrifuge tube was removed and 10 ml of distilled water was added. The mixture was shaken evenly and allowed to stand for 24 hours. The distilled water in the centrifuge tube was removed and distilled water was added again. The mixture was shaken evenly and allowed to stand for 24 hours. The above method was repeated three times. The volume of the montmorillonite after being washed with distilled water was read and the water washing resistance of the montmorillonite was calculated. The results are shown in Table 2.

[0043] Table 2 Water wash resistance of sodium montmorillonite after being treated with different concentrations of reagents

[0044]

[0045] The above is only a preferred embodiment of the present invention, which shows and describes the basic principles, main features and advantages of the present invention, but does not limit the scope of patent protection of the present invention. Those skilled in the art should understand that the present invention is not limited by the above embodiments. In addition to the above embodiments, the present invention may have other implementation modes without departing from the spirit and scope of the present invention. The present invention may also have various changes and improvements, and all technical solutions formed by equivalent substitution or equivalent transformation fall within the scope of protection required by the present invention. The scope of protection required by the present invention is defined by the attached claims and their equivalents. The technical features not described in the present invention can be realized by or using existing technologies, which will not be repeated here.

Claims

1. A method for preparing a cationic self-assembled high temperature resistant clay stabilizer, characterized in that: The following steps are included in sequence: Firstly, N-methylbenzylamine, diethylenetriamine and epichlorohydrin are subjected to substitution reaction to prepare polyquaternary ammonium containing quaternary ammonium ions and benzyl groups; then mono-6-amino-β-cyclodextrin is reacted with epichlorohydrin to prepare β-cyclodextrin-epichlorohydrin condensate; finally, the above two substances are blended and assembled to generate a cationic assembly complex with high cationic degree and strong temperature resistance.

2. The method for preparing the cationic self-assembly high temperature resistant clay stabilizer according to claim 1, characterized in that: The polyquaternary ammonium containing quaternary ammonium ions and benzyl groups in the cationic assembly complex provides quaternary ammonium cations combined with anionic charges on the surface of the formation clay mineral on the one hand, and provides benzene rings combined with the β-CD holes of the β-cyclodextrin-epichlorohydrin condensate on the other hand.

3. A method for preparing a cationic self-assembled high temperature resistant clay stabilizer, characterized in that: The raw materials include N-methylbenzylamine, diethylenetriamine, epichlorohydrin and mono-6-amino-β-cyclodextrin, and the steps are sequentially as follows: S1, take 12.0g N-methylbenzylamine and add it to 70ml distilled water, heat it to 60℃, stir and dissolve, introduce nitrogen, slowly add 9.5g epichlorohydrin dropwise, control the dropping speed, keep the reaction temperature at 60℃, need 2 hours, then continue to keep the reaction temperature for 3 hours, cool it to room temperature, generate a light yellow viscous transparent liquid, set aside; S2, take 1.0g of diethylenetriamine and add it to 70ml of distilled water, cool it to 10°C, slowly add 3.7g of epichlorohydrin, control the dropping speed, keep the reaction temperature below 10°C, take 1 hour, after the dropping is completed, warm it to room temperature to generate a light yellow transparent liquid, set aside; S3, the light yellow viscous transparent liquid generated in the above S1 is fully mixed with the light yellow liquid generated in the above S2, the temperature is raised to 70°C, stirred for reaction for 3 hours, and the temperature is lowered to room temperature to generate a yellow viscous transparent liquid, which is set aside; S4, dissolve 8.5g of mono-6-amino-β-cyclodextrin and 0.5g of sodium hydroxide in 50ml of distilled water, heat to 40°C, introduce nitrogen, then add 2.3g of epichlorohydrin in batches under stirring for 2 hours, and keep warm for 3 hours after the addition to obtain a light yellow viscous liquid for standby use; S5. Fully mix the light yellow viscous transparent liquid produced in S3 and the light yellow viscous liquid produced in S4, and perform ultrasonic oscillation to obtain a yellow viscous transparent liquid.

4. The method for preparing the cationic self-assembly high temperature resistant clay stabilizer according to claim 3, characterized in that: The reaction formula of step S1 is as follows:

5. The method for preparing the cationic self-assembly high temperature resistant clay stabilizer according to claim 3, characterized in that: The reaction formula of step S2 is as follows:

6. The method for preparing the cationic self-assembly high temperature resistant clay stabilizer according to claim 3, characterized in that: The reaction formula of step S3 is as follows:

7. The method for preparing the cationic self-assembly high temperature resistant clay stabilizer according to claim 3, characterized in that: The reaction formula of step S4 is as follows:

8. A cationic self-assembled high temperature resistant clay stabilizer, characterized in that: Prepared by any of the above methods.

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