Copolymer demulsifier as well as preparation method and application thereof

Abstract

The preparation method comprises the following steps: uniformly mixing a substance containing a primary amine group, diglycidyl ether and an organic solvent, carrying out a reaction under a protective atmosphere, and carrying out reduced pressure distillation to remove the organic solvent so as to prepare the copolymer demulsifier. The preparation raw materials are wide, easy to obtain and low in price, the synthesis process conforms to green chemistry, and no waste is generated. The diglycidyl ether used in the invention is a small molecular compound with strong hydrophobicity, and the substance containing the primary amine group is hydroxylamine with strong hydrophilicity, so the synthesis safety is guaranteed, the cost of the raw materials is reduced, the prepared copolymer demulsifier is a long-chain polymer with a hydrophilic-hydrophobic-hydrophilic structure, and the copolymer demulsifier can be used in the field of emulsion preparation. And meanwhile, hydrophilic short side groups are connected, so that the demulsifying agent has the capabilities of effectively reducing interfacial tension and breaking an original interfacial film, and can effectively promote the demulsification process.

Description

Technical Field

[0001] The invention belongs to the field of oilfield chemicals and relates to a copolymer demulsifier and a preparation method and application thereof. Background Art

[0002] Although efforts are being made to find alternative energy sources to crude oil, such as solar energy, hydrogen produced by decomposing water, wind energy, etc., crude oil remains one of the most important energy sources in the world. In addition, crude oil is an indispensable resource for various petrochemical industries. With the decline of conventional oil and gas resources, unconventional resources have been promoted, developed and utilized, especially heavy oil and oil sands reserves. Heavy crude oil accounts for half of the world's oil reserves. However, the production of heavy crude oil has many problems in the production, transportation, storage and refining processes. It usually contains more natural emulsifiers such as asphaltenes, resins, cyclohexane acids and solid particles than light and medium crude oils. These components help to form very stable crude oil emulsions with brine. These emulsions increase the viscosity of crude oil and cause corrosion to various equipment such as pipelines, pumps and storage tanks. In addition, the presence of ions in these emulsions can cause catalyst poisoning in downstream processes. Therefore, the dehydration of these emulsions is key to avoid these problems. Various methods have been applied to the dehydration of crude oil emulsions, including chemical, physical / mechanical and biological. However, chemical agents are the most applicable method due to their low cost and short dehydration time. Surfactants are the most commonly used chemicals for crude oil emulsification and dehydration. However, they also have some limitations, such as limited solubility under harsh conditions such as high salinity, high temperature, and toxicity.

[0003] The demulsifiers currently used are mainly polyoxyethylene polyoxypropylene block polyether (EO-PO) demulsifiers and their related modified products. The demulsification effect of this type of demulsifier is not ideal, and there are problems such as high demulsification temperature, long demulsification time, low demulsification efficiency and poor broad-spectrum adaptability to different crude oil products. In addition, the raw materials of this type of demulsifier are mostly petroleum alkylphenols, which are not only expensive, but also have a complex production process and certain risks. Therefore, it is urgent to develop a new type of demulsifier with a simple, safe and green production process. Summary of the invention

[0004] The purpose of the present invention is to solve the problems in the prior art, to provide a copolymer demulsifier and a preparation method and application thereof, to solve the problems in the prior art such as poor demulsification performance, high demulsifier temperature, poor adaptability and poor resistance to harsh conditions.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A copolymer demulsifier, the structural formula of the copolymer demulsifier is:

[0007]

[0008] A method for preparing the copolymer demulsifier comprises:

[0009] The substance containing primary amine groups, diglycidyl ether and organic solvent are uniformly mixed, reacted under a protective atmosphere, and the organic solvent is removed by reduced pressure distillation to obtain a copolymer demulsifier.

[0010] Furthermore, the organic solvent is one or more of cyclohexane, toluene, xylene, N,N-dimethylformamide and dimethyl sulfoxide.

[0011] Furthermore, the substance containing a primary amine group is one or more of ethanolamine, 3-aminopropanol, 4-amino-1-butanol, aniline and benzylamine.

[0012] Furthermore, the diglycidyl ether is one or more of hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether and resorcinol diglycidyl ether.

[0013] Furthermore, the molar ratio of the substance containing primary amine groups to diglycidyl ether is 0.8-1.2:1.

[0014] Furthermore, the mass ratio of the substance containing primary amine groups to the organic solvent is 5 to 20:1.

[0015] Furthermore, the reaction temperature is 80-150° C., and the reaction time is 5-20 hours.

[0016] Furthermore, the protective atmosphere is nitrogen.

[0017] The application of the copolymer demulsifier in demulsifying crude oil emulsion.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The present invention provides a method for preparing a copolymer demulsifier, using a substance containing a primary amine group and diglycidyl ether as reaction raw materials, and preparing a target copolymer demulsifier through a one-step simple, safe and controllable synthesis process. The preparation raw materials of the present invention are widely available and low in price, the synthesis process complies with green chemistry, and no waste is generated. In addition, the diglycidyl ether used in the present invention is a small molecule compound with strong hydrophobicity, and the substance containing a primary amine group used is a hydroxylamine with strong hydrophilicity, which not only ensures the safety of the synthesis, but also reduces the cost of raw materials. The prepared copolymer demulsifier is a long-chain polymer with a hydrophilic-hydrophobic-hydrophilic structure, and is connected to a hydrophilic short side group at the same time, has the ability to effectively reduce interfacial tension and break the original interfacial film, can effectively promote the demulsification process, and the preparation time and demulsification time of the demulsifier are greatly reduced, which can effectively reduce the cost of the agent.

[0020] The present invention also provides a copolymer demulsifier, which introduces a hydrophilic short side group and a large π bond structure of a benzene ring into the molecule. Compared with other polyether demulsifiers, the hydrophilic short side group and the hydrophilic part in the main chain help the demulsifier migrate to the oil-water interface to destroy the oil-water interface film. The large π bond structure of the benzene ring can interact with surfactants such as asphaltene at the interface through n-π and π-π to destroy the interface film, increase film drainage, and promote demulsification performance. Compared with low molecular weight demulsifiers, the copolymer demulsifier has a higher molecular weight, can bridge between emulsified droplets, promote collision, coalescence, and flocculation between droplets, thereby improving demulsification efficiency. The copolymer demulsifier prepared by the present invention has the characteristics of low demulsification temperature, short demulsification time, excellent demulsification performance, acid, alkali, and salt resistance, and has a certain demulsification efficiency for crude oil emulsions with different water contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0022] Figure 1 This is a schematic diagram of the synthesis principle of the copolymer demulsifier prepared in Example 1 of the present invention.

[0023] Figure 2 This is the infrared spectrum of the copolymer demulsifier prepared in Example 1 of the present invention. DETAILED DESCRIPTION

[0024] In order to enable those skilled in the art to understand the characteristics and effects of the present invention, the following is a general description and definition of the terms and expressions mentioned in the specification and claims. Unless otherwise specified, all technical and scientific terms used in the text are the common meanings understood by those skilled in the art for the present invention. In the event of a conflict, the definition in this specification shall prevail.

[0025] The theories or mechanisms described and disclosed herein, whether correct or incorrect, should not limit the scope of the present invention in any way, that is, the present invention can be implemented without being limited by any specific theory or mechanism.

[0026] Herein, all features such as values, quantities, contents and concentrations defined in the form of numerical ranges or percentage ranges are for simplicity and convenience only. Accordingly, the description of numerical ranges or percentage ranges should be considered to have included and specifically disclosed all possible secondary ranges and individual values ​​within the range (including integers and fractions).

[0027] In this document, unless otherwise specified, “includes,” “including,” “contains,” “has,” or similar terms cover the meanings of “consisting of” and “mainly consisting of,” for example, “A includes a” covers the meanings of “A includes a and other” and “A only includes a.”

[0028] In this document, in order to make the description concise, not all possible combinations of various technical features in various embodiments or examples are described. Therefore, as long as there is no contradiction in the combination of these technical features, the various technical features in various embodiments or examples can be combined arbitrarily, and all possible combinations should be considered to be within the scope of this specification.

[0029] The present invention will be further described below in conjunction with specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and are not intended to limit the scope of the present invention. In addition, it should be understood that after reading the content taught by the present invention, those skilled in the art can make various changes or modifications to the present invention, and these equivalent forms fall within the scope limited by the appended claims of the application equally.

[0030] The following examples use conventional instruments and equipment in the art. The experimental methods in the following examples where specific conditions are not specified are usually carried out under conventional conditions or under conditions recommended by the manufacturer. The various raw materials used in the following examples are conventional commercial products unless otherwise specified, and their specifications are conventional specifications in the art. In the specification of the present invention and the following examples, unless otherwise specified, "%" means weight percentage, "part" means weight part, and ratio means weight ratio.

[0031] The present invention is described in further detail below:

[0032] The present invention provides a copolymer demulsifier and a preparation method and application thereof, comprising the following steps:

[0033] Using nitrogen as protective gas, the substance containing primary amine groups, diglycidyl ether and organic solvent are uniformly mixed, reacted at 80-150° C. for 5-20 hours, and the organic solvent is removed by reduced pressure distillation to obtain the copolymer demulsifier.

[0034] Preferably, the molar ratio of the substance containing primary amine groups to diglycidyl ether is 0.8-1.2:1.

[0035] Preferably, the mass ratio of the substance containing primary amine groups to the organic solvent is 5 to 20:1.

[0036] Preferably, the substance containing a primary amine group is one or more of ethanolamine, 3-aminopropanol, 4-amino-1-butanol, aniline, and benzylamine.

[0037] Preferably, the diglycidyl ether is one or more of hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether, and resorcinol diglycidyl ether.

[0038] Preferably, the organic solvent is one or more of cyclohexane, toluene, xylene, N,N-dimethylformamide, and dimethyl sulfoxide.

[0039] The above method for preparing a copolymer demulsifier prepares a copolymer demulsifier.

[0040] The use of the copolymer demulsifier in crude oil emulsion demulsification includes the following steps: dissolving the copolymer demulsifier in a solvent to obtain a solution, and then mixing the solution with the crude oil emulsion at 40-70° C. and standing for 0.5-3 hours. After the demulsification is completed, the oil-water interface is clear, the water phase is clear, and the water content in the oil phase is low.

[0041] Preferably, the solvent is at least one of water, ethanol, toluene and xylene.

[0042] Preferably, the mass fraction of the solution is 0.2wt% to 1wt%.

[0043] Preferably, the volume ratio of the solution to the crude oil emulsion is 1:10-20.

[0044] The present invention is further described in detail below in conjunction with specific embodiments:

[0045] Example 1

[0046] This embodiment provides a copolymer demulsifier, which is obtained by the following steps:

[0047] Using nitrogen as protective gas, 1 mol of 4-amino-1-butanol, 1 mol of bisphenol A diglycidyl ether and 1 L of N,N-dimethylformamide were uniformly mixed and reacted at 120°C for 4 hours, and the organic solvent was removed by vacuum distillation to obtain the copolymer demulsifier. The reaction principle is as follows: Figure 1 shown.

[0048] Depend on Figure 2 It can be seen that at 1610.8cm -1 The peak at 1372.1cm belongs to the skeleton vibration of the benzene ring. -1 The peak at 1252.5 cm is caused by the in-plane bending vibration of OH. -1 The peak at 1124.5cm is caused by the stretching vibration of CN. -1 and 1095.3cm -1 The peak at is caused by the stretching vibration of CO. These results indicate that the target product was successfully synthesized.

[0049] Example 2

[0050] This embodiment provides a copolymer demulsifier, which is obtained by the following steps:

[0051] Using nitrogen as protective gas, 1 mol of ethanolamine, 1 mol of bisphenol A diglycidyl ether and 1 L of N,N-dimethylformamide were uniformly mixed and reacted at 120° C. for 8 hours, and the organic solvent was removed by reduced pressure distillation to obtain the copolymer demulsifier.

[0052] Example 3

[0053] This embodiment provides a copolymer demulsifier, which is obtained by the following steps:

[0054] Using nitrogen as protective gas, 1 mol of benzylamine, 1 mol of bisphenol A diglycidyl ether and 1 L of N,N-dimethylformamide were uniformly mixed and reacted at 100° C. for 6 hours, and the organic solvent was removed by reduced pressure distillation to obtain the copolymer demulsifier.

[0055] Example 4

[0056] This embodiment provides a copolymer demulsifier, which is obtained by the following steps:

[0057] Using nitrogen as protective gas, 1 mol of aniline, 1 mol of neopentyl glycol diglycidyl ether and 1 L of xylene were uniformly mixed and reacted at 120° C. for 12 hours, and the organic solvent was removed by reduced pressure distillation to obtain the copolymer demulsifier.

[0058] Example 5

[0059] This embodiment provides a copolymer demulsifier, which is obtained by the following steps:

[0060] Using nitrogen as protective gas, 1 mol of ethanolamine, 1 mol of hexanediol diglycidyl ether and 20 ml of xylene were mixed and reacted at 120° C. for 12 hours, and the organic solvent was removed by distillation under reduced pressure to obtain the copolymer demulsifier.

[0061] Example 6

[0062] The copolymer demulsifier prepared in Examples 1 to 5 was used to characterize the demulsification performance of the copolymer demulsifier in crude oil emulsion.

[0063] 150 parts by mass of crude oil (source: Changqing Oilfield, Xi'an, China, density at 25°C: 0.862 g / cm 3, viscosity at 25°C: 7.6 mPa·s, asphaltene: 14wt%, resin: 6.03wt%, wax: 15.46%, water: 1.6wt%) were added into 350 parts by mass of deionized water, stirred and mixed, heated to 70°C, and then stirred at a speed of 11000 r / min for 20 min. This process was repeated three times until a stable oil-in-water emulsion was obtained.

[0064] The copolymer demulsifiers prepared in Examples 1 to 5 were added into ethanol to prepare demulsifier solutions with a mass fraction of 0.6%, namely, experimental groups 1 to 5.

[0065] 1 volume part of the above copolymer demulsifier solution was added to 20 volume parts of crude oil emulsion and then mixed evenly, and then transferred to a 50°C water bath and allowed to stand for 3 hours. The demulsification efficiency was characterized by measuring its dehydration rate (refer to the Petroleum and Natural Gas Industry Standard SY / T 5281-2000 of the People's Republic of China). The results are shown in Table 1.

[0066] Table 1 Demulsification results of experimental groups 1 to 5

[0067] Group Copolymer demulsifier (mg / L) Demulsification efficiency (%) Experimental Group 1 300 100 Experimental Group 2 300 93.8 Experimental Group 3 300 36.1 Experimental Group 4 300 24.9 Experimental Group 5 300 0

[0068] Note: "Copolymer demulsifier (mg / L)" in the table refers to the concentration of copolymer demulsifier in crude oil emulsion.

[0069] As shown in Table 1, the copolymer demulsifiers prepared in Examples 1 to 2 all have very good demulsification performance. The demulsification efficiency of Example 1 is the highest, the copolymer demulsifier prepared in Example 5 has no demulsification effect, and the demulsification performance of the copolymer demulsifiers prepared in Examples 3 and 4 is poor. The main reason is that the differences in molecular structure and hydrophilicity of the copolymer demulsifiers lead to different demulsification capabilities.

[0070] Example 7

[0071] Based on the copolymer demulsifier prepared in Example 1, copolymer demulsifier solutions with different concentrations were prepared to characterize the demulsification performance of copolymer demulsifiers with different concentrations in crude oil emulsion.

[0072] 150 parts by mass of crude oil were added to 350 parts by mass of deionized water, stirred and mixed, heated to 70° C., and then stirred at a speed of 11000 r / min for 20 min. This process was repeated three times until a stable water-in-oil emulsion was obtained.

[0073] Different weight portions of the copolymer demulsifier prepared in Example 1 were added to ethanol to prepare demulsifier solutions with mass fractions of 1%, 0.8%, 0.6%, 0.4% and 0.2%, respectively. The obtained samples were recorded as experimental groups 6 to 10; the blank group was 0%, and the sample was recorded as experimental group 11.

[0074] 1 volume part of the above experimental groups 6 to 11 was added to 20 volume parts of crude oil emulsion and mixed evenly, and then transferred to a 50° C. water bath and allowed to stand for 3 hours. The dehydration rate was measured. The results are shown in Table 2.

[0075] Table 2 Demulsification results of experimental groups 6 to 11

[0076] Group Copolymer demulsifier (mg / L) Demulsification efficiency (%) Experimental Group 6 500 100 Experimental Group 7 400 100 Experimental Group 8 300 100 Experimental Group 9 200 92.7 Experimental Group 10 100 78.9 Experimental Group 11 0 0

[0077] Note: "Copolymer demulsifier (mg / L)" in the table refers to the concentration of copolymer demulsifier in crude oil emulsion.

[0078] As shown in Table 2, the copolymer demulsifier provided in Example 1 of the present invention has good demulsification performance. When the concentration of the copolymer demulsifier is 100 mg / L, the demulsification efficiency is 78.9%; when the demulsification concentration is 300 mg / L, the demulsification efficiency can reach 100%.

[0079] Example 8

[0080] Based on the copolymer demulsifier prepared in Example 1, experimental groups 12 to 15 were established in sequence to characterize the demulsification performance of the copolymer demulsifier at different temperatures and times.

[0081] 150 parts by mass of crude oil were added to 350 parts by mass of deionized water, stirred and mixed, heated to 70° C., and then stirred at a speed of 11000 r / min for 20 min. This process was repeated three times until a stable water-in-oil emulsion was obtained.

[0082] The copolymer demulsifier prepared in Example 1 was added into ethanol to prepare a solution with a mass fraction of 0.6%.

[0083] 1 volume part of the above copolymer demulsifier solution was added to 20 volume parts of crude oil emulsion and mixed evenly, and then transferred to water baths set at different temperatures and allowed to stand for 3 hours. The dehydration rate was measured. The results are shown in Table 3.

[0084] Table 3 Demulsification results of experimental groups 12 to 15

[0085]

[0086] As shown in Table 3, the copolymer demulsifier provided in Example 1 of the present invention can achieve 100% demulsification efficiency at 50° C. for 120 min, and 100% demulsification efficiency at 70° C. for 30 min.

[0087] Example 9

[0088] Based on the copolymer demulsifier prepared in Example 1, experimental groups 16 to 21 were established in sequence to characterize the demulsification performance of the copolymer demulsifier under different pH conditions.

[0089] 150 parts by mass of crude oil are added to 350 parts by mass of deionized water and stirred to mix. The pH value is adjusted by adding hydrochloric acid or sodium hydroxide, heated to 70°C, and then stirred at a speed of 11000 r / min for 20 minutes. This process is repeated three times until a stable oil-in-water emulsion is obtained.

[0090] The copolymer demulsifier prepared in Example 1 was added into ethanol to prepare a solution with a mass fraction of 0.6%.

[0091] 1 volume part of the above copolymer demulsifier solution was added to 20 volume parts of crude oil emulsions with different pH values ​​and then mixed evenly. The mixture was then transferred to a 50° C. water bath and allowed to stand for 3 h. The dehydration rate was measured. The results are shown in Table 4.

[0092] Table 4 Demulsification results of experimental groups 16 to 21

[0093] Group pH Demulsification efficiency (%) Experimental Group 16 2 93.9 Experimental Group 17 4 98.4 Experimental Group 18 6 100 Experimental Group 19 7 100 Experimental Group 19 8 100 Experimental Group 20 10 93.1 Experimental Group 21 12 84.6

[0094] It can be seen from Table 4 that the copolymer demulsifier provided in Example 1 of the present invention has a high demulsification efficiency within the pH range of strong acid and strong base.

[0095] Example 10

[0096] Based on the copolymer demulsifier prepared in Example 1, experimental groups 22 to 27 were established in sequence to characterize the demulsification performance of the copolymer demulsifier under different salinity conditions.

[0097] 150 parts by mass of crude oil were added to 350 parts by mass of deionized water and stirred to mix. The salinity was adjusted by adding sodium chloride, heated to 70°C, and then stirred at a speed of 11000 r / min for 20 minutes. This process was repeated three times until a stable oil-in-water emulsion was obtained.

[0098] The copolymer demulsifier prepared in Example 1 was added into ethanol to prepare a solution with a mass fraction of 0.6%.

[0099] 1 volume part of the above copolymer demulsifier solution was added to 20 volume parts of crude oil emulsions with different pH values ​​and mixed evenly. The mixture was then transferred to a 50° C. water bath and allowed to stand for 3 h. The dehydration rate was measured. The results are shown in Table 5.

[0100] Table 5 Demulsification results of experimental groups 22 to 27

[0101] Group Salinity (mg / L) Demulsification efficiency (%) Experimental Group 22 0 100 Experimental Group 23 10000 100 Experimental Group 24 20000 100 Experimental Group 25 30000 100 Experimental Group 26 40000 100 Experimental Group 27 50000 100

[0102] It can be seen from Table 5 that the copolymer demulsifier provided in Example 1 of the present invention can have a stable demulsification efficiency under high salinity conditions, indicating that the demulsifier has high salt resistance.

[0103] The invention provides a copolymer demulsifier which is suitable for demulsifying crude oil emulsion and has the characteristics of simple preparation method, short demulsification time, low demulsification temperature, excellent demulsification performance and the like.

[0104] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A copolymer demulsifier, characterized in that: The structural formula of the copolymer demulsifier is:

2. A method for preparing the copolymer demulsifier according to claim 1, characterized in that: include: The substance containing primary amine groups, diglycidyl ether and organic solvent are uniformly mixed, reacted under a protective atmosphere, and the organic solvent is removed by reduced pressure distillation to obtain a copolymer demulsifier.

3. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The organic solvent is one or more of cyclohexane, toluene, xylene, N,N-dimethylformamide and dimethyl sulfoxide.

4. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The substance containing a primary amine group is one or more of ethanolamine, 3-aminopropanol, 4-amino-1-butanol, aniline and benzylamine.

5. The method for preparing the copolymer demulsifier according to claim 2, characterized in that: The diglycidyl ether is one or more of hexanediol diglycidyl ether, neopentyl glycol diglycidyl ether, glycerol diglycidyl ether and resorcinol diglycidyl ether.

6. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The molar ratio of the substance containing primary amine groups to diglycidyl ether is 0.8-1.2:

1.

7. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The mass ratio of the substance containing primary amine groups to the organic solvent is 5 to 20:

1.

8. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The reaction temperature is 80-150° C., and the reaction time is 5-20 hours.

9. The method for preparing a copolymer demulsifier according to claim 2, characterized in that: The protective atmosphere is nitrogen.

10. Use of the copolymer demulsifier according to claim 1 in demulsifying crude oil emulsion.

Images