A nanocomposite viscosity reducer, its preparation method and application

Abstract

The application discloses a kind of nanometer composite viscosity reducer and its preparation method and application, belong to petroleum exploitation technical field.The preparation method of the nanometer composite viscosity reducer includes: mica powder is uniformly dispersed in solvent, amino type silane and methyl acryloyl oxygen type silane are added, is stirred sufficiently under 1200-2000rpm, filtration, washing, drying, and the modified mica powder is obtained;Modified mica powder is dried at 75-85 DEG C for 6-10h, then ultrasonic dispersion is in dimethylbenzene, and the modified mica powder dispersion liquid is obtained;Ester monomer is added to the modified mica powder dispersion liquid, initiator is further added, 20-40min nitrogen is passed to remove air in reactor, then it is reacted at 60-70 DEG C for 6-10h, product is washed by centrifugation with ethanol, after drying, and the nanometer composite viscosity reducer is obtained.The nanometer composite viscosity reducer can realize efficient viscosity reduction under high temperature condition.

Description

Technical Field

[0001] This application relates to a nanocomposite viscosity reducer, its preparation method, and its application, belonging to the field of petroleum extraction technology. Background Technology

[0002] With the decreasing proven reserves of conventional crude oil and the declining production of older oilfields, heavy oil resources are becoming increasingly important. However, the high viscosity of heavy oil and the stability of heavy oil / water emulsions formed beneath formations limit its extraction and application. Therefore, the petroleum engineering field has seen numerous systematic studies focusing on developing clean, efficient, and economically feasible flow control technologies. Chemical viscosity reducers, due to their high stability and viscosity-reducing capabilities, have become a current research hotspot.

[0003] Chinese invention patent CN108484908B discloses a method for preparing a necklace-type active polymer viscosity reducer for heavy oil using 1,2,3,5-tetra-p-toluenesulfonic acid inositol ester, 1,4-diazacyclohexane, and N,N-dimethyldococarboxylic acid as main raw materials. First, 1,2,3,5-tetra-p-toluenesulfonic acid inositol ester is polymerized with an equal amount of 1,4-diazacyclohexane, and then reacted with twice the amount of N,N-dimethyldococarboxylic acid to prepare an amphiphilic polymer with a special main chain structure. This polymer has a significant ability to reduce the viscosity of asphaltene-based heavy oil. However, for deep or extra-heavy oil reservoirs, where bottom-hole temperatures can reach 180°C, the above-mentioned viscosity reducer is at risk of thermal decomposition or hydrolysis under long-term high-temperature conditions, leading to molecular chain breakage and loss of viscosity-reducing ability. Summary of the Invention

[0004] To address the aforementioned issues, a nanocomposite viscosity reducer, its preparation method, and its application are provided, which can achieve efficient viscosity reduction under high-temperature conditions.

[0005] The technical solution adopted in this invention is as follows: According to one aspect of this application, a method for preparing a nanocomposite viscosity reducer is provided, comprising the following steps: (1) Disperse mica powder evenly in a solvent, add diamino silane and methacryloxy silane, stir thoroughly at 1200-2000 rpm, filter, wash, and dry to obtain modified mica powder; (2) The modified mica powder is dried at 75-85℃ for 6-10h, and then ultrasonically dispersed in xylene to obtain a modified mica powder dispersion. (3) Add ester monomers to the modified mica powder dispersion, then add initiator, purge with nitrogen for 20-40 min to remove air from the reactor, and then react at 60-70℃ for 6-10 h. The product is washed with ethanol by centrifugation and dried to obtain nanocomposite viscosity reducer.

[0006] Optionally, in step (1), the weight ratio of mica powder, diamino silane and methacryloxy silane is (1-3):1:(1.2-1.5).

[0007] Optionally, in step (1), the solvent is deionized water and ethanol in a weight ratio of 1:(3-5); And / or, the diamino silane is at least one selected from N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; And / or, the methacryloyloxy silane is 3-methacryloyloxypropyltrimethoxysilane or 3-methacryloyloxypropylmethyldimethoxysilane.

[0008] Optionally, in step (3), the method for preparing the ester monomer includes the following steps: α-Methylbenzyl alcohol and a polymerization inhibitor are placed in a reaction vessel and heated to melt at 40-60°C. Then, 2-sulfoethyl methacrylate and a catalyst are added, and the reaction is carried out at 90-110°C. When no more liquid flows out of the condenser, the reaction is stopped after another 0.3-0.8 hours. The product is filtered, and the unreacted 2-sulfoethyl methacrylate is collected by vacuum distillation. The ester monomer is obtained from the discharge.

[0009] Optionally, the polymerization inhibitor is hydroquinone or 4-methoxyphenol; And / or, the catalyst is sodium hydroxide or potassium hydroxide.

[0010] Optionally, the molar ratio of 2-sulfoethyl methacrylate to α-methylbenzyl alcohol is (2-3):1; And / or, the amount of catalyst used is 4-6% of the total reactant weight; And / or, the amount of the polymerization inhibitor is 2-4% of the total weight of the reactants.

[0011] Optionally, in step (3), the amount of modified mica powder used is 20-25% of the weight of the ester monomer.

[0012] Optionally, in step (3), the initiator is azobisisobutyronitrile.

[0013] According to another aspect of this application, a nanocomposite viscosity reducer prepared by the preparation method of the nanocomposite viscosity reducer as described in any of the above claims is provided.

[0014] According to another aspect of this application, an application of the nanocomposite viscosity reducer as described above in heavy oil viscosity reduction is provided.

[0015] In this application, "%" refers to wt%.

[0016] The beneficial effects of this application include, but are not limited to: 1. This application discloses a nanocomposite viscosity reducer, its preparation method, and its application. The nanocomposite viscosity reducer has advantages such as small size, large specific surface area, and good dispersibility. It can penetrate into the interior of the heavy oil stacking structure and fully contact the heavy oil. Its surface polymer chains have appropriate steric hindrance. Mica particles, as a natural layered silicate mineral, can exert their adsorption effect, effectively disrupting the heavy oil stacking structure and thus reducing the viscosity of the heavy oil. In particular, the amino group in the diamino silane faces the aqueous phase, and ionization in water makes the nanoparticles positively charged. This facilitates the adsorption of nanoparticles onto the negatively charged oil droplet surface, effectively preventing oil droplet aggregation and forming an emulsion with smaller particle size and more uniform distribution. This allows the ester monomers to fully contact the heavy oil, maximizing the disruption of the high-viscosity structure inside the heavy oil. The synergistic effect of the two results in a better viscosity reduction effect.

[0017] 2. The nanocomposite viscosity reducer of this application, its preparation method and application, the synergistic effect of mica nanoparticles and benzene rings and sulfonic acid groups in ester monomers enables the viscosity reducer to achieve high efficiency under high temperature conditions. The ester groups in ester monomers increase the compatibility of nanocomposite viscosity reducers with heavy oil, enhancing the disruption of the heavy oil's structural composition and thus improving the viscosity-reducing effect. The gums and asphaltenes in heavy oil are macromolecular aggregates composed of benzene rings, and the conjugated stacking of these rings significantly increases the viscosity. Introducing benzene rings into ester monomers can increase the disruption of the stacked structure of heavy oil, thus enhancing the viscosity-reducing effect. Besides non-polar alkane components, heavy oil also contains a large number of polar groups and heteroatoms, making it prone to forming hydrogen bonds between molecules, leading to increased viscosity. The sulfonic acid groups in ester monomers can form hydrogen bonds with heavy oil, disrupting the original structure. Furthermore, sulfonic acid groups ionize in water to form negatively charged sulfonate ions. When viscosity reducer molecules adsorb onto the surface of asphaltenite particles, these particles acquire the same charge, forming electrostatic repulsion that effectively prevents the disintegrated asphaltenite particles from re-aggregating, allowing them to be stably dispersed in the oil phase as tiny particles, thereby significantly reducing the system's viscosity. Detailed Implementation

[0018] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0019] Unless otherwise specified in the examples, the procedures shall be performed under standard conditions or conditions recommended by the manufacturer. Raw materials or instruments whose manufacturers are not specified are all commercially available products.

[0020] The average particle size of the mica powder mentioned below is 80 nm.

[0021] Example 1 A method for preparing a nanocomposite viscosity reducer includes the following steps: (1) Disperse mica powder evenly in deionized water and ethanol in a weight ratio of 1:4, add N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 3-methacryloyloxypropyltrimethoxysilane, the weight ratio of mica powder, N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and 3-methacryloyloxypropyltrimethoxysilane is 2:1:1.3, stir thoroughly at 1500 rpm, filter, wash and dry to obtain modified mica powder; (2) The modified mica powder was dried at 80°C for 8 hours and then ultrasonically dispersed in xylene to obtain a modified mica powder dispersion. (3) Place α-methylbenzyl alcohol and 3% hydroquinone by weight of total reactants in a reaction vessel and heat to melt at 50°C. Then add 2-sulfoethyl methacrylate and 5% sodium hydroxide by weight of total reactants. The molar ratio of 2-sulfoethyl methacrylate to α-methylbenzyl alcohol is 2.5:1. React at 100°C. When no more liquid flows out of the condenser, react for another 0.5 hours and then stop the reaction. Filter and distill the product under reduced pressure. Collect the unreacted 2-sulfoethyl methacrylate and the ester monomer is obtained from the discharge. (4) Add ester monomers to the modified mica powder dispersion. The amount of modified mica powder is 23% of the weight of the ester monomers. Then add azobisisobutyronitrile. Purge with nitrogen for 30 min to remove air from the reactor. Then react at 65°C for 8 h. Wash the product with ethanol by centrifugation and dry it to obtain the nanocomposite viscosity reducer.

[0022] Example 2 A method for preparing a nanocomposite viscosity reducer includes the following steps: (1) Disperse mica powder evenly in deionized water and ethanol in a weight ratio of 1:3, add N-(2-aminoethyl)-3-aminopropyltriethoxysilane and 3-methacryloyloxypropylmethyldimethoxysilane, the weight ratio of mica powder, N-(2-aminoethyl)-3-aminopropyltriethoxysilane and 3-methacryloyloxypropylmethyldimethoxysilane is 1:1:1.2, stir thoroughly at 1200 rpm, filter, wash and dry to obtain modified mica powder; (2) The modified mica powder was dried at 75°C for 10 h and then ultrasonically dispersed in xylene to obtain a modified mica powder dispersion. (3) Place α-methylbenzyl alcohol and 2% of the total reactants of 4-methoxyphenol in a reaction vessel and heat to melt at 40°C. Then add 2-sulfoethyl methacrylate and 4% of the total reactants of potassium hydroxide. The molar ratio of 2-sulfoethyl methacrylate to α-methylbenzyl alcohol is 2:1. React at 90°C. When no more liquid flows out of the condenser, react for another 0.8 hours and then stop the reaction. Filter and distill the product under reduced pressure. Collect the unreacted 2-sulfoethyl methacrylate and the ester monomer is obtained from the discharge. (4) Add ester monomers to the modified mica powder dispersion. The amount of modified mica powder is 20% of the weight of the ester monomers. Then add azobisisobutyronitrile. Purge with nitrogen for 20 min to remove air from the reactor. Then react at 60℃ for 10 h. The product is washed with ethanol by centrifugation and dried to obtain the nanocomposite viscosity reducer.

[0023] Example 3 A method for preparing a nanocomposite viscosity reducer includes the following steps: (1) Disperse mica powder evenly in deionized water and ethanol in a weight ratio of 1:5, add N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and 3-methacryloyloxypropyltrimethoxysilane, the weight ratio of mica powder, N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane and 3-methacryloyloxypropyltrimethoxysilane is 3:1:1.5, stir thoroughly at 2000 rpm, filter, wash and dry to obtain modified mica powder; (2) The modified mica powder was dried at 85°C for 6 hours and then ultrasonically dispersed in xylene to obtain a modified mica powder dispersion. (3) Place α-methylbenzyl alcohol and 4% hydroquinone by weight of total reactants in a reaction vessel and heat to melt at 60°C. Then add 2-sulfoethyl methacrylate and 6% sodium hydroxide by weight of total reactants. The molar ratio of 2-sulfoethyl methacrylate to α-methylbenzyl alcohol is 3:1. React at 110°C. When no more liquid flows out of the condenser, react for another 0.3 hours and then stop the reaction. Filter and distill the product under reduced pressure. Collect the unreacted 2-sulfoethyl methacrylate and the ester monomer is obtained from the discharge. (4) Add ester monomers to the modified mica powder dispersion. The amount of modified mica powder is 25% of the weight of the ester monomers. Then add azobisisobutyronitrile. Purge with nitrogen for 40 min to remove air from the reactor. Then react at 70°C for 6 h. The product is washed with ethanol by centrifugation and dried to obtain a nanocomposite viscosity reducer.

[0024] Comparative Example 1 The difference from Example 1 is that α-methylbenzyl alcohol is replaced with dodecaol.

[0025] Comparative Example 2 The difference from Example 1 is that 2-sulfoethyl methacrylate is replaced with methyl methacrylate.

[0026] Comparative Example 3 The difference from Example 1 is that step (3) is not disclosed, and the ester monomer in step (4) is replaced with methyl methacrylate.

[0027] Comparative Example 4 The difference from Example 1 is that mica powder is replaced with SiO2.

[0028] Comparative Example 5 The difference from Example 1 is that in step (1), N-(2-aminoethyl)-3-aminopropyltrimethoxysilane is replaced with 3-epoxypropoxypropyltrimethoxysilane.

[0029] Comparative Example 6 The difference from Example 1 is that 3-methacryloyloxypropyltrimethoxysilane was not added in step (1).

[0030] Comparative Example 7 The difference from Example 1 is that in step (4), the amount of modified mica powder used is 40% of the weight of the ester monomer.

[0031] The nanocomposite viscosity reducers prepared in Examples 1-3 and Comparative Examples 1-7 were tested for their viscosity-reducing properties in heavy oil emulsions. The testing process included: the heavy oil was from a well in Shengli Oilfield, with a viscosity of 15680 mPa·s at 100°C and a viscosity reducer dosage of 2000 mg / kg; a viscosity of 1875 mPa·s at 150°C and a viscosity reducer dosage of 1500 mg / kg; and a viscosity of 528 mPa·s at 180°C and a viscosity reducer dosage of 1000 mg / kg. The apparent viscosity of each emulsion was tested using a rotational viscometer, and the corresponding viscosity reduction rate of the heavy oil was calculated according to the following formula.

[0032] μ%=(η-η1) 100 / η Where η represents the apparent viscosity of the heavy oil sample, and η1 represents the apparent viscosity of the sample after emulsification and viscosity reduction.

[0033] The results are shown in Table 1 below: Table 1

[0034] The above description is merely an embodiment of this application, and the scope of protection of this application is not limited to these specific embodiments, but is determined by the claims of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the technical concept and principles of this application should be included within the scope of protection of this application.

Claims

1. A method for preparing a nanocomposite viscosity reducer, characterized in that, Includes the following steps: (1) Disperse mica powder evenly in a solvent, add diamino silane and methacryloxy silane, stir thoroughly at 1200-2000 rpm, filter, wash, and dry to obtain modified mica powder; (2) The modified mica powder is dried at 75-85℃ for 6-10h, and then ultrasonically dispersed in xylene to obtain a modified mica powder dispersion. (3) Add ester monomers to the modified mica powder dispersion, then add initiator, purge with nitrogen for 20-40 min to remove air from the reactor, and then react at 60-70℃ for 6-10 h. The product is washed with ethanol by centrifugation and dried to obtain nanocomposite viscosity reducer.

2. The preparation method of the nanocomposite viscosity reducer according to claim 1, characterized in that, In step (1), the weight ratio of mica powder, diamino silane and methacryloxy silane is (1-3):1:(1.2-1.5).

3. The preparation method of the nanocomposite viscosity reducer according to claim 1, characterized in that, In step (1), the solvent is deionized water and ethanol in a weight ratio of 1:(3-5); And / or, the diamino silane is at least one selected from N-(2-aminoethyl)-3-aminopropyltrimethoxysilane, N-(2-aminoethyl)-3-aminopropyltriethoxysilane, and N-(2-aminoethyl)-3-aminopropylmethyldimethoxysilane; And / or, the methacryloyloxy silane is 3-methacryloyloxypropyltrimethoxysilane or 3-methacryloyloxypropylmethyldimethoxysilane.

4. The preparation method of the nanocomposite viscosity reducer according to claim 1, characterized in that, In step (3), the preparation method of the ester monomer includes the following steps: α-Methylbenzyl alcohol and a polymerization inhibitor are placed in a reaction vessel and heated to melt at 40-60°C. Then, 2-sulfoethyl methacrylate and a catalyst are added, and the reaction is carried out at 90-110°C. When no more liquid flows out of the condenser, the reaction is stopped after another 0.3-0.8 hours. The product is filtered, and the unreacted 2-sulfoethyl methacrylate is collected by vacuum distillation. The ester monomer is obtained from the discharge.

5. The preparation method of the nanocomposite viscosity reducer according to claim 4, characterized in that, The polymerization inhibitor is hydroquinone or 4-methoxyphenol; And / or, the catalyst is sodium hydroxide or potassium hydroxide.

6. The method for preparing the nanocomposite viscosity reducer according to claim 4, characterized in that, The molar ratio of 2-sulfoethyl methacrylate to α-methyl benzyl alcohol is (2-3):1; And / or, the amount of catalyst used is 4-6% of the total reactant weight; And / or, the amount of the polymerization inhibitor is 2-4% of the total weight of the reactants.

7. The method for preparing the nanocomposite viscosity reducer according to claim 1, characterized in that, In step (3), the amount of modified mica powder used is 20-25% of the weight of the ester monomer.

8. The method for preparing the nanocomposite viscosity reducer according to claim 1, characterized in that, In step (3), the initiator is azobisisobutyronitrile.

9. A nanocomposite viscosity reducer prepared by the preparation method of the nanocomposite viscosity reducer as described in any one of claims 1-8.

10. The application of the nanocomposite viscosity reducer as described in claim 9 in the viscosity reduction of heavy oil.

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