Dehydration and desalination efficient demulsifier and preparation method thereof

Abstract

The invention discloses a dehydrating and desalting efficient demulsifying agent and a preparation method thereof. Epoxy resin is adopted as a cross-linking agent to carry out cross-linking modification on demulsifier polyether, acetic acid is used for neutralization, then maleic anhydride is used for esterification, and a solvent is added to form the monoester modified polyether demulsifier. The molecular weight of the polyether is effectively increased due to crosslinking of the epoxy resin, the dehydration effect is excellent, and carboxyl at the end group can be well complexed with metal ions, so that the polyether has better dehydration and desalination effects. Compared with unmodified polyether, the polyether modified by epoxy resin and maleic anhydride has a certain improvement in dehydration capability, and the polyether is compounded with other polyether having a certain dehydration advantage on an oil field as a single agent, so that the effect is better.

Description

Technical Field

[0001] The invention relates to the technical field of oilfield chemical industry, in particular to a high-efficiency demulsifier for dehydration and desalination and a preparation method thereof. Background Art

[0002] Crude oil desalination has always been a very important issue in oil processing. Although their content is very small, their harm is very serious. In salty crude oil, dehydration is achieved by demulsification. Salts that are not dissolved in water are prone to form salt scale, which affects the heat transfer efficiency, increases fuel consumption and shortens the life of the equipment; after heating, the inorganic salts in the crude oil will hydrolyze to form hydrogen chloride, which will affect the pipelines for oil transportation and accelerate the corrosion of the pipelines. In addition, as oil field exploitation enters the middle and late stages, the water content and stability of crude oil in most oil fields increase, but in crude oil processing, the water content and salt content of crude oil need to meet strict indicators to ensure the safety and efficiency of crude oil processing. Therefore, if crude oil wants to be deeply dehydrated, it is necessary not only to optimize the dehydration and desalting process, but also to optimize the demulsifier, change the conventional synthesis route, and change its properties and increase its functions on the basis of increasing the molecular weight of the demulsifier. Summary of the invention

[0003] In order to solve the above technical problems, the present invention provides a dehydration and desalination high-efficiency demulsifier and a preparation method. The demulsifier not only increases the molecular weight of polyether by epoxy resin crosslinking, but also forms a monoester by esterifying the polyether modified by maleic anhydride, which plays a role in complexing metal ions in salt-containing comprehensive oil samples. The demulsifier of the present invention can be used in high-salt oil fields and has excellent dehydration effect.

[0004] In a first aspect, the present invention provides a method for preparing a high-efficiency demulsifier for dehydration and desalination, which is achieved by adopting the following technical scheme.

[0005] A method for preparing a high-efficiency demulsifier for dehydration and desalination comprises the following steps:

[0006] S1. The polyether and the metal hydroxide alkaline solution are mixed uniformly, the temperature is raised to above 100°C, and then the vacuum is evacuated for dehydration and deoxygenation, and then the epoxy resin solution is added dropwise at 90 to 110°C, and the reaction is stirred and kept warm for a period of time to obtain a modified polyether; wherein the mass ratio of the polyether, the metal hydroxide, and the epoxy resin is 100:(0.5 to 1):(1 to 3);

[0007] S2. Lower the temperature to 70-80°C and neutralize with acetic acid to a pH of 6-7; wherein the mass ratio of the modified polyether obtained in step S1 to acetic acid is 100:(0.5-1);

[0008] S3. Maintaining the temperature at 70-80°C, stirring the maleic anhydride and the neutralized modified polyether obtained in step S2 for a period of time, the mass ratio of the neutralized modified polyether to the maleic anhydride is 100:(3-6); lowering the temperature to below 60°C, adding a solvent, and discharging.

[0009] Furthermore, in step S1, the polyether is a polyether obtained by connecting propylene oxide and ethylene oxide with diethylenetriamine, tetraethylenepentamine, polyethylenepolyamine, phenolic resin, or phenolamine resin as initiators; wherein the mass ratio of the initiator to propylene oxide is 1:(39-199), and the mass ratio of propylene oxide to ethylene oxide is (1-5):1.

[0010] Furthermore, in step S1, the metal hydroxide is potassium hydroxide or sodium hydroxide.

[0011] Furthermore, in step S1, the epoxy resin is selected from one or more of ethylene glycol diglycidyl ether, E51, and E44.

[0012] Furthermore, in step S1, epoxy resin is dissolved in any one of heavy aromatic hydrocarbons, high boiling point aromatic hydrocarbons and xylene to prepare a 30wt%-60wt% epoxy resin solution. Specifically, the heavy aromatic hydrocarbons are C10 crude aromatic hydrocarbons (in accordance with "SH / T1804 Industrial C10 Crude Aromatic Hydrocarbons" Type I); the high boiling point aromatic hydrocarbons are SA-1500.

[0013] Furthermore, in step S1, the vacuuming time is 30 to 50 minutes.

[0014] Furthermore, in step S1, the epoxy resin solution is added dropwise for 20 to 40 minutes.

[0015] Furthermore, in step S1, the polyether and epoxy resin are stirred and kept warm for a reaction time of 1.5 to 2 hours.

[0016] Furthermore, in step S3, the stirring reaction time of maleic anhydride and the modified polyether obtained in step S2 is 1.5 to 2 hours.

[0017] Furthermore, in step S3, the solvent is selected from one or more of heavy aromatics, high boiling point aromatics, xylene, methanol, and ethanol. Specifically, the heavy aromatics are C10 crude aromatics (in accordance with "SH / T 1804 Industrial C10 Crude Aromatics" Type I); the high boiling point aromatics are SA-1500.

[0018] Furthermore, in step S3, the solvent is a water-soluble solvent, and the water-soluble solvent is methanol and water or ethanol and water.

[0019] Furthermore, in step S3, after adding the solvent, the concentration of the demulsifier sample is 30wt%-60wt%.

[0020] In a second aspect, the present invention provides a high-efficiency demulsifier for dehydration and desalination, which is achieved by adopting the following technical solution.

[0021] A high-efficiency demulsifier for dehydration and desalination prepared by the above preparation method.

[0022] In a third aspect, the present invention provides a composite demulsifier, which is achieved by adopting the following technical solution.

[0023] A composite demulsifier comprises the above-mentioned high-efficiency demulsifier for dehydration and desalination and a polyether demulsifier, wherein the mass ratio of the high-efficiency demulsifier for dehydration and desalination to the polyether demulsifier is (2-5):1.

[0024] Furthermore, the polyether in the polyether demulsifier is selected from polyethers obtained by connecting propylene oxide and ethylene oxide with diethylenetriamine, tetraethylenepentamine, polyethylenepolyamine, phenolic resin, and phenolamine resin as initiators; wherein the mass ratio of the initiator to propylene oxide is 1:(39-199), and the mass ratio of propylene oxide to ethylene oxide is (1-5):1.

[0025] This application has the following beneficial effects.

[0026] The present invention adopts cross-linking agent epoxy resin to cross-link polyether under alkaline conditions, neutralizes with acetic acid, and finally esterifies with maleic anhydride to form a monoester modified polyether demulsifier. Since the end group of the demulsifier of the present invention contains carboxyl groups, it can well complex the metal ions of salt in the high-salt oil sample to achieve the effect of salt resistance, and since the molecular weight of the polyether is effectively increased by the cross-linking of the epoxy resin, the dehydration effect is also very significant. At this time, it is compounded with other polyethers for use, and the effect is better. The demulsifier of the present invention can effectively demulsify under high-salt conditions and is suitable for high-salt oil fields. DETAILED DESCRIPTION

[0027] The present patent application is further described below in conjunction with embodiments.

[0028] Unless otherwise specified, the experimental methods used in the following preparation examples and examples are all conventional methods; the materials, reagents, etc. used in the following preparation examples and examples are all commercially available unless otherwise specified.

[0029] The preparation method of the phenolamine resin used in the examples of this application can be found in the following literature: Wei Qiang, Du Dawei, Li Zhiwen, Guo Haijun, etc. An amine-modified phenolic resin and its preparation method [P]. CN104231197A.2014-12-24.

[0030] Example 1

[0031] A method for preparing a high-efficiency demulsifier for dehydration and desalination comprises the following steps:

[0032] Add 166g of phenolamine resin and 3g of potassium hydroxide catalyst to the reaction kettle, raise the temperature and start stirring at the same time. When the temperature rises to above 90°C, evacuate and dehydrate under reduced pressure for 30 minutes. When the temperature rises to above 120°C, add 830g of propylene oxide, control the reaction temperature between 140°C and 150°C, and continue to react until negative pressure after the addition is completed; cool to below 70°C, discharge, and obtain phenolamine resin polyoxypropylene ether.

[0033] Add 70g of phenolamine resin polyoxypropylene ether to the reactor, heat up, and vacuum and stir at the same time. When the temperature rises to above 90°C, close the vacuum valve and add 3g of catalyst potassium hydroxide to the reactor. Continue to heat up and vacuum. When the temperature rises to above 100°C, decompress and dehydrate. After the dehydration is qualified, nitrogen replacement is carried out, and replacement is carried out 3 times in total. Vacuum, when the temperature rises to above 120°C, add 630g of propylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed. Add 140g of ethylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed, then vacuum to remove the unreacted monomers, and cool to below 85°C to discharge. The synthetic polyether is named FP-001.

[0034] 50g of polyether FP-001 was added to the reactor, 1g of 50% potassium hydroxide solution was added to the reactor and mixed evenly, the temperature was raised to 110°C, vacuumed for 30 minutes until the water was filtered out, 3g of 50% ethylene glycol diglycidyl ether of C10 crude aromatics (C10 crude aromatics in this embodiment are industrial products purchased from Tianjin Hongshun Chemical Co., Ltd.) solution was added dropwise (i.e., 1.5g of ethylene glycol diglycidyl ether was dissolved in C10 crude aromatics), the temperature was maintained at 110°C, and the reaction was kept warm for 1.5 hours. After the reaction, the temperature was lowered to 80°C, 0.5g of acetic acid was added dropwise, stirred evenly, 3g of maleic anhydride was added, the temperature was maintained at 80°C, the reaction was kept warm for 1.5 hours, the temperature was lowered to below 60°C, 43g of C10 crude aromatics (C10 crude aromatics in this embodiment are industrial products purchased from Tianjin Hongshun Chemical Co., Ltd.), 10g of methanol were added, and the material was discharged after stirring evenly. The synthetic demulsifier was named FP-001JL001.

[0035] Example 2

[0036] A method for preparing a high-efficiency demulsifier for dehydration and desalination comprises the following steps:

[0037] Add 90g of phenolamine resin polyoxypropylene ether in Example 1 to the reactor, heat up, and vacuumize and stir at the same time. When the temperature rises to above 90°C, close the vacuum valve and add 3g of catalyst potassium hydroxide to the reactor. Continue to heat up and vacuumize. When the temperature rises to above 100°C, decompress and dehydrate. After the dehydration is qualified, nitrogen replacement is carried out, and a total of 3 replacements are made. Vacuum, when the temperature rises to above 120°C, add 510g of propylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed. Add 200g of ethylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed, then vacuumize to remove unreacted monomers, and cool to below 85°C to discharge. The synthetic polyether is named FP-002.

[0038] 50g of polyether FP-002 was added to the reactor, 1g of 50% potassium hydroxide solution was added to the reactor and mixed evenly, the temperature was raised to 110°C, vacuumed for 30 minutes until the water was filtered out, 3g of 50% E51 C10 crude aromatics (C10 crude aromatics in this embodiment are industrial products purchased from Tianjin Hongshun Chemical Co., Ltd.) solution was added dropwise for 25 minutes, and 110°C was maintained unchanged, and the reaction was kept warm for 1.5 hours. After the reaction, the temperature was lowered to 80°C, 0.5g of acetic acid was added dropwise, stirred evenly, 3g of maleic anhydride was added, the temperature was maintained at 80°C, and the reaction was kept warm for 1.5 hours, and the temperature was lowered to below 60°C, 45g of C10 crude aromatics (C10 crude aromatics in this embodiment are industrial products purchased from Tianjin Hongshun Chemical Co., Ltd.), 8g of methanol were added, and the material was discharged after stirring evenly. The synthetic demulsifier was named FP-002JL002.

[0039] Add 166g of polyethylene polyamine (CAS No. 29320-38-5) and 3g of potassium hydroxide catalyst to the reactor, heat up, and start stirring at the same time. When the temperature rises to above 90°C, evacuate and dehydrate under reduced pressure for 30 minutes. When the temperature rises to above 120°C, add 830g of propylene oxide, control the reaction temperature between 140°C and 150°C, and continue to react until negative pressure is reached after the addition is completed; cool to below 70°C, discharge, and obtain polyethylene polyamine polyoxypropylene ether.

[0040] Add 30g of polyethylene polyamine polyoxypropylene ether to the reactor, heat it up, and vacuum it while stirring. When the temperature rises to above 90°C, close the vacuum valve and add 3g of catalyst potassium hydroxide to the reactor. Continue to heat up and vacuumize. When the temperature rises to above 100°C, decompress and dehydrate. After the dehydration is qualified, replace with nitrogen for a total of 3 times. Vacuum it. When the temperature rises to above 120°C, add 470g of propylene oxide, control the reaction temperature between 140°C and 150°C, and continue to react for 30 minutes after the addition is completed. Add 125g of ethylene oxide, control the reaction temperature between 140°C and 150°C, and continue to react for 30 minutes after the addition is completed. Then vacuumize to remove the unreacted monomers and cool to below 85°C to discharge. Add 500g of xylene (analytical grade, Tianzheng brand) and 125g of methanol, and the synthetic demulsifier is named AP-002.

[0041] The two demulsifiers FP-002JL002 and AP-002 were compounded in a mass ratio of 3:1 to obtain the composite demulsifier FHPRJ-001.

[0042] Example 3

[0043] A method for preparing a high-efficiency demulsifier for dehydration and desalination comprises the following steps:

[0044] Add 80g of polyethylene polyamine polyoxypropylene ether in Example 2 to the reactor, heat up, and vacuum and stir at the same time. When the temperature rises to above 90°C, close the vacuum valve and add 3g of catalyst potassium hydroxide to the reactor. Continue to heat up and vacuumize. When the temperature rises to above 100°C, decompress and dehydrate. After the dehydration is qualified, nitrogen replacement is carried out, and a total of 3 replacements are carried out. Vacuum, when the temperature rises to above 120°C, add 587g of propylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed. Add 222g of ethylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed, then vacuumize to remove unreacted monomers, and cool to below 85°C to discharge. The synthetic polyether is named AP-001.

[0045] Add 50g of polyether AP-001 to the reactor, add 1g of 50% potassium hydroxide solution to the reactor and mix evenly, heat to 110°C, vacuum for 30 minutes until the water is filtered out, add 3g of 50% ethylene glycol diglycidyl ether carbon ten crude aromatic hydrocarbon (industrial product, Tianjin Hongshun Chemical Co., Ltd.) solution, add for 25 minutes, maintain 110°C unchanged, and keep warm for 1.5 hours. After the reaction, cool to 80°C, add 0.5g of acetic acid, stir evenly, add 3g of maleic anhydride, maintain the temperature at 80°C unchanged, keep warm for 1.5 hours, cool to below 60°C, add 38g of carbon ten crude aromatic hydrocarbon (industrial product, Tianjin Hongshun Chemical Co., Ltd.), 15g of methanol, stir evenly and discharge. The synthetic demulsifier is named AP-001JL001.

[0046] Add 30g of phenolamine resin polyoxypropylene ether in Example 1 to the reactor, heat up, and vacuumize and stir at the same time. When the temperature rises to above 90°C, close the vacuum valve and add 3g of catalyst potassium hydroxide to the reactor. Continue to heat up and vacuumize. When the temperature rises to above 100°C, decompress and dehydrate. After the dehydration is qualified, nitrogen replacement is carried out, and a total of 3 replacements are made. Vacuum, when the temperature rises to above 120°C, add 470g of propylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed. Add 333g of ethylene oxide, control the reaction temperature between 140°C-150°C, and continue to react for 30 minutes after the addition is completed, then vacuumize to remove unreacted monomers, and cool to below 85°C to discharge. Add 666g of xylene (analytical grade, Tianzheng brand) and 167g of methanol, and the synthetic demulsifier is named FP-003.

[0047] The two demulsifiers AP-001JL001 and FP-003 were compounded in a mass ratio of 1:1 to obtain the composite demulsifier FHPRJ-002.

[0048] Performance test 1

[0049] For the comprehensive oil sample of a high-salt oilfield S (salt content ≈ 9000 mg / L), at the field temperature, the performance of the synthesized demulsifier was evaluated according to the requirements and steps in the "Q / HS2020 Technical Requirements and Inspection Specifications for Crude Oil Demulsifiers", and the dehydration amount, dehydration rate, dehydration water color and dehydration interface of the demulsifier were observed. See Table 1 for details.

[0050] Table 1

[0051]

[0052] The performance evaluation results of the demulsifier synthesized in Example 1 show that the dehydration speed and dehydration rate of the polyether FP-001 are significantly improved after being modified by the modification method described in Example 1. This indicates that the polyether modification method of the present invention can improve the dehydration performance of the demulsifier.

[0053] Performance test 2

[0054] For the comprehensive oil sample of a high-salt oilfield C (salt content ≈ 90,000 mg / L), at the field temperature, the performance of the synthesized demulsifier was evaluated according to the requirements and steps in "Q / HS2020 Technical Requirements and Inspection Specifications for Crude Oil Demulsifiers", and the dehydration amount, dehydration rate, dehydration water color and dehydration interface of the demulsifier were observed. See Table 2 for details.

[0055] Table 2

[0056]

[0057] The performance evaluation results of the demulsifier synthesized in Example 2 show that the dehydration rate of the polyether FP-002 is significantly improved after being modified by the modification method described in Example 2. The dehydration rate and dehydration speed of the modified polyether are significantly improved when compounded with AP-002 with a smaller molecular weight, indicating that the polyether modification method of the present invention can improve the dehydration performance of the demulsifier to a certain extent, and the dehydration performance is better when it is compounded with other polyethers.

[0058] Performance test 3

[0059] For the comprehensive oil sample of a high-salt oilfield in Q (salt content ≈ 10000 mg / L), the performance of the synthesized demulsifier was evaluated at the field temperature according to the requirements and steps in the "Q / HS2020 Technical Requirements and Inspection Specifications for Crude Oil Demulsifiers", and the dehydration amount, dehydration rate, dehydration water color and dehydration interface of the demulsifier were observed. See Table 3 for details.

[0060] Table 3

[0061]

[0062] The performance evaluation results of the demulsifier synthesized in Example 3 show that after the polyether AP-001 is modified by the modification method described in Example 3, its dehydration speed and dehydration rate are significantly improved. When the modified polyether is compounded with FP-003, its dehydration rate and dehydration speed are significantly improved, indicating that the polyether modification method of the present invention can improve the dehydration performance of the demulsifier to a certain extent, and when it is compounded with other polyethers, the dehydration performance is better.

[0063] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing a high-efficiency demulsifier for dehydration and desalination, characterized in that: The following steps are involved: S1. The polyether and the metal hydroxide alkaline solution are mixed uniformly, the temperature is raised to above 100°C, and then the vacuum is evacuated for dehydration and deoxygenation, and then the epoxy resin solution is added dropwise at 90 to 110°C, and the reaction is stirred and kept warm for a period of time to obtain a modified polyether; wherein the mass ratio of the polyether, the metal hydroxide, and the epoxy resin is 100:(0.5 to 1):(1 to 3); S2. Lower the temperature to 70-80°C and neutralize with acetic acid to a pH of 6-7; wherein the mass ratio of the modified polyether obtained in step S1 to acetic acid is 100:(0.5-1); S3. Maintaining the temperature at 70-80°C, stirring the maleic anhydride and the neutralized modified polyether obtained in step S2 for a period of time, the mass ratio of the neutralized modified polyether to the maleic anhydride is 100:(3-6); lowering the temperature to below 60°C, adding a solvent, and discharging.

2. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S1, the polyether is a polyether obtained by using diethylenetriamine, tetraethylenepentamine, polyethylenepolyamine, phenolic resin, or phenolamine resin as initiators to connect propylene oxide and ethylene oxide; wherein the mass ratio of the initiator to propylene oxide is 1:(39-199), and the mass ratio of propylene oxide to ethylene oxide is (1-5):

1.

3. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S1, the metal hydroxide is potassium hydroxide or sodium hydroxide.

4. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S1, the epoxy resin is selected from one or more of ethylene glycol diglycidyl ether, E51, and E44.

5. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S1, the vacuuming time is 30 to 50 minutes.

6. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S1, the epoxy resin solution is added dropwise for 20 to 40 minutes.

7. The method for preparing a high-efficiency demulsifier for dehydration and desalination according to claim 1, characterized in that: In step S3, the solvent is selected from one or more of heavy aromatic hydrocarbons, high boiling point aromatic hydrocarbons, xylene, methanol, and ethanol; or the solvent is selected from a water-soluble solvent, and the water-soluble solvent is selected from methanol and water or ethanol and water.

8. A high-efficiency demulsifier for dehydration and desalination prepared by the preparation method according to any one of claims 1 to 7.

9. A composite demulsifier, characterized in that: The invention comprises the high-efficiency dehydration and desalination demulsifier and the polyether demulsifier as described in claim 8, wherein the mass ratio of the high-efficiency dehydration and desalination demulsifier to the polyether demulsifier is (2-5):

1.

10. A composite demulsifier according to claim 9, characterized in that: The polyether in the polyether demulsifier is selected from polyethers obtained by connecting propylene oxide and ethylene oxide with diethylenetriamine, tetraethylenepentamine, polyethylenepolyamine, phenolic resin, and phenolamine resin as initiators; wherein the mass ratio of the initiator to propylene oxide is 1:(39-199), and the mass ratio of propylene oxide to ethylene oxide is (1-5):1.

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