High-efficiency demulsifier for oil field and preparation method thereof

Abstract

The present application relates to a kind of high-efficiency demulsifier for oil field and its preparation method, belong to the technical field of petroleum additive.The demulsifier is compounded by hyperbranched demulsification main agent, non-ionic surfactant and oily solvent, wherein the hyperbranched demulsification main agent is prepared by the following steps: first, dimerization glycerol is esterified with methacryloyl chloride to obtain half-ester intermediate, then open ring reaction is carried out with glycerol triglycidyl ether to form hyperbranched matrix, finally, alkyl thiol and alkenyl click chemistry reaction are introduced into the alkyl branch chain containing sulfur ester.The demulsifier utilizes the multi-site bridging effect of hyperbranched skeleton and strong hydrophilicity to promote water droplet coalescence, and at the same time, the compatibility with crude oil is enhanced by alkyl branch chain, rapid interfacial penetration and high-efficiency demulsification are realized.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of petroleum aids, and particularly relates to a high-efficiency demulsifier for oil fields and a preparation method thereof. BACKGROUND

[0002] In the process of crude oil production, especially after the use of water injection, polymer flooding and other enhanced oil recovery technologies, the produced liquid usually forms a stable "water-in-oil" emulsion. The stability of this emulsion is mainly due to the natural existence of surface active substances such as asphaltene, resin, paraffin micelles and solid particles in crude oil, which adsorb at the oil-water interface and form a layer of strong and mechanically strong interface film, preventing the coalescence and sedimentation of water droplets. Therefore, a demulsifier must be added for pretreatment to destroy this stability and achieve efficient separation of oil and water to meet the strict requirements of crude oil transportation, processing and wastewater injection.

[0003] The commonly used demulsifiers at present mainly include the following types:

[0004] Polyether demulsifiers: represented by ethylene oxide-propylene oxide block copolymers (such as SP-169, AE series, etc.), the molecular structure of which is mostly linear or slightly branched. Although this type of demulsifier has certain amphiphilic properties, due to the relatively simple molecular structure and limited steric hindrance effect, it is difficult to effectively destroy the stable interface film composed of complex components such as asphaltene, resulting in poor dehydration rate and poor adaptability to different types of crude oil.

[0005] Branched polymer demulsifiers: such as polyether with phenolic resin, polyethylene polyamine as initiator, which increases the steric volume by increasing the branching degree of the molecule. Although this type of product enhances the water phase convergence ability to some extent, due to the poor controllability of the molecular structure and the uneven branching degree, the demulsification efficiency is low.

[0006] Polymer demulsifiers: including polyacrylate, polysiloxane, etc., which provide different demulsification mechanisms through special molecular structures. However, this type of demulsifier is often too specific for the produced liquid of a particular oil field, has low universality, and the application effect fluctuates greatly under different oil field conditions.

[0007] In summary, the existing demulsifier technology still has obvious deficiencies in demulsification efficiency and dehydration rate, and it is urgent to develop a new type of demulsifier with high demulsification efficiency and wide applicability. SUMMARY

[0008] In order to solve the technical problems mentioned in the background art, the purpose of the present application is to provide a polyanion sodium ion battery positive electrode composite material.

[0009] The purpose of the present application can be achieved by the following technical solutions:

[0010] An oil field high-efficiency demulsifier, the specific components are: hyperbranched demulsification main agent 37-42wt%, defoaming agent 1.5-2.0wt% and corrosion inhibitor 0.12-0.18wt%, the balance is solvent.

[0011] The hyperbranched demulsification main agent is prepared by the following method:

[0012] Step A1: premix dimeric glycerol and anhydrous tetrahydrofuran, pass dry nitrogen and add potassium carbonate and anhydrous magnesium sulfate mixture, ice water bath control temperature is 0-10℃, slowly add methacryloyl chloride stirring reaction 6-8h, after the reaction is over, filter out salt, rotary evaporation recovery tetrahydrofuran, get semi-esterification intermediate;

[0013] Further, the amount ratio of dimeric glycerol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate and anhydrous tetrahydrofuran is 0.1mol:0.2mol:15-18g:3-4g:550-700mL, the active primary hydroxyl of methacryloyl chloride reacts with dimeric glycerol to form esterification.

[0014] Step A2: premix semi-esterification intermediate, glycerol triglycidyl ether and toluene, then add triethylamine and triphenylphosphine mixture, under nitrogen protection, heat to 90-100℃ stirring reflux reaction 2.5-3.3h, after the reaction is over, remove and recover toluene under reduced pressure, get hyperbranched matrix;

[0015] Further, the amount ratio of semi-esterification intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1mol:70-80mmol:4.5-6mL:15-20mg:220-300mL, the active epoxy group of glycerol triglycidyl ether opens ring with the secondary hydroxyl in semi-esterification intermediate molecule to form hyperbranched compound starting with glycerol.

[0016] Step A3: mix the hyperbranched matrix, alkyl mercaptan, photoinitiator and dimethyl formamide uniformly, carry out ultraviolet irradiation at room temperature with 20-25mW / cm 2 Stirring reaction for 10-15h, after the reaction is over, add deionized water to mix and wash, centrifugal separate the water phase, then vacuum dry to get hyperbranched demulsification main agent;

[0017] Further, the amount ratio of hyperbranched matrix, alkyl mercaptan, photoinitiator and dimethyl formamide is 50g:80-120mmol:0.12-0.16g:150-200mL, the alkyl mercaptan carries out thiol-ene click addition with hyperbranched matrix and is grafted onto the hyperbranched skeleton;

[0018] Further, the alkyl mercaptan is one of dodecanethiol and hexadecanethiol, which has better compatibility and permeability with oil phase matrix under the length of alkyl chain.

[0019] Preferably, the defoaming agent is a silicone preparation, which has good compatibility in the oil-based demulsification system, and has stable foam inhibition and defoaming ability for water-in-oil oilfield displacement liquid.

[0020] Preferably, the corrosion inhibitor is a bimodal imidazole preparation, which has strong adsorption to metal and self-deemulsification function.

[0021] A preparation method of a high-efficiency demulsifier for oil fields, specifically: premixing a defoaming agent, a corrosion inhibitor and a solvent, then adding a hyperbranched demulsification main agent and mixing uniformly, and vacuum defoaming to obtain the demulsifier.

[0022] The beneficial effects of the present application are:

[0023] The hyperbranched demulsification main agent provided by the present application realizes significant improvement of demulsification performance through unique molecular design. The core technical advantages are reflected in the following aspects:

[0024] Firstly, the hyperbranched skeleton structure endows the demulsifier with excellent space effect. Compared with traditional linear polyether demulsifiers, the hyperbranched structure has a three-dimensional configuration, which can provide greater steric hindrance effect and more effectively destroy the oil-water interface film. The rich ether bonds and hydroxyl groups in the skeleton form a strong hydrophilic region, which strongly adsorbs water molecules through hydrogen bonding, significantly reduces the oil-water interfacial tension, and provides driving force for the coalescence of water droplets.

[0025] Secondly, the sulfur-containing ester alkyl branch introduced by alkyl mercaptan click chemistry realizes good compatibility of the demulsifier with the crude oil system. These alkyl chains act as "anchoring groups" and can quickly penetrate into the oil-water interface to compete with natural emulsifiers in the crude oil for interface positions. The introduction of sulfur atoms not only enhances the polarity of the molecule, but also provides additional electronic effects, which helps to interact specifically with components such as asphaltene, thereby more effectively destroying the stable interface film.

[0026] In terms of demulsification mechanism, the demulsifier of the present application exhibits multiple synergistic effects: the hyperbranched skeleton acts as a "bridge" to connect multiple emulsified water droplets, promoting their flocculation and coalescence; the hydrophilic region extracts water from the interface film through strong hydration, reducing the film strength; and the alkyl branch ensures that the molecule quickly locates and penetrates into the interface. This multi-mode demulsification mechanism enables it to adapt to crude oil emulsions of different properties, exhibiting excellent versatility.

[0027] Compared with existing technologies, the demulsifier of this invention significantly improves the dehydration rate and dehydration percentage while maintaining high demulsification efficiency. Traditional polyether-type demulsifiers, due to their simple molecular structure, often struggle to cope with the complex and ever-changing oilfield environment; while ordinary branched polymers, although improving the steric effect to some extent, have limited demulsification efficiency. This invention, through precise molecular design, organically combines the steric advantages of hyperbranched structures with the interfacial activity of specific functional groups, achieving a breakthrough improvement in demulsification performance. Detailed Implementation

[0028] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0029] Example 1: Preparation of a high-efficiency demulsifier for oilfield use. The specific implementation method is as follows:

[0030] I. Preparation of Hyperbranching Demulsifying Agent

[0031] Step A1: Premix dipropylene glycol and anhydrous tetrahydrofuran, purge with dry nitrogen gas and add potassium carbonate and anhydrous magnesium sulfate, mix, control the temperature in an ice-water bath at 0℃, slowly add methacryloyl chloride and stir for 8 hours. The ratio of dipropylene glycol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate and anhydrous tetrahydrofuran is 0.1mol:0.2mol:15g:3g:550mL. After the reaction is complete, filter to remove salt and rotary evaporate to recover tetrahydrofuran to obtain a semi-esterified intermediate.

[0032] Step A2: Take the semi-esterification intermediate, glycerol triglycidyl ether and toluene, premix them, then add triethylamine and triphenylphosphine and mix them. Under nitrogen protection, heat to 90°C and stir and reflux for 3.3 h. The ratio of semi-esterification intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1 mol: 70 mmol: 4.5 mL: 15 mg: 220 mL. After the reaction is completed, remove and recover toluene by rotary evaporation under reduced pressure to obtain the hyperbranched matrix.

[0033] Step A3: Take the hyperbranched matrix, dodecanethiol, photoinitiator (all photoinitiator 1173), and dimethylformamide, mix them thoroughly, and heat at room temperature at 20 mW / cm 2 The mixture was subjected to ultraviolet irradiation and stirred for 12 hours. The ratio of hyperbranched matrix, dodecanethiol, photoinitiator and dimethylformamide was 50 g: 80 mmol: 0.12 g: 150 mL. After the reaction was completed, deionized water was added for washing, the aqueous phase was separated by centrifugation, and then vacuum dried to obtain the hyperbranched demulsifier.

[0034] II. Preparation of Demulsifier

[0035] The ingredients are prepared according to the following weight percentages: 37 wt% hyperbranching demulsifier, prepared in this embodiment; 2.0 wt% defoamer, using an organosilicon formulation, specifically MOMENTIVE® Silbreak 638; 0.12 wt% corrosion inhibitor, using a diimidazole formulation, specifically PC-HS antiemulsification corrosion inhibitor; the remainder is solvent, which is a mixture of ethylene glycol monobutyl ether and ethanol in a 2:1 weight ratio.

[0036] The defoamer, corrosion inhibitor and solvent are premixed, and then the hyperbranched demulsifier is added and mixed evenly. The demulsifier is obtained by vacuum degassing.

[0037] Example 2: Preparation of a high-efficiency demulsifier for oilfield use. The specific implementation method is as follows:

[0038] I. Preparation of Hyperbranching Demulsifying Agent

[0039] Step A1: Premix dipropylene glycol and anhydrous tetrahydrofuran, purge with dry nitrogen gas and add potassium carbonate and anhydrous magnesium sulfate, mix, and control the temperature in an ice-water bath at 10°C. Slowly add methacryloyl chloride and stir for 6 hours. The ratio of dipropylene glycol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 18 g: 4 g: 700 mL. After the reaction is complete, filter to remove salt and rotary evaporate to recover tetrahydrofuran to obtain a semi-esterified intermediate.

[0040] Step A2: Take the semi-esterification intermediate, glycerol triglycidyl ether and toluene, premix them, then add triethylamine and triphenylphosphine and mix them. Under nitrogen protection, heat to 95°C and stir and reflux for 2.8 h. The ratio of semi-esterification intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1 mol: 75 mmol: 5.2 mL: 17 mg: 240 mL. After the reaction is completed, remove and recover toluene by rotary evaporation under reduced pressure to obtain the hyperbranched matrix.

[0041] Step A3: Mix the hyperbranched matrix, dodecyl mercaptan, photoinitiator, and dimethylformamide thoroughly at room temperature with 20 mW / cm 2 The mixture was subjected to ultraviolet irradiation and stirred for 10 hours. The ratio of hyperbranched matrix, dodecanethiol, photoinitiator and dimethylformamide was 50 g: 90 mmol: 0.14 g: 160 mL. After the reaction was completed, deionized water was added for washing, the aqueous phase was separated by centrifugation, and then vacuum dried to obtain the hyperbranched demulsifier.

[0042] II. Preparation of Demulsifier

[0043] The ingredients are prepared according to the following weight percentages: 40 wt% hyperbranching demulsifier, prepared in this embodiment; 1.8 wt% defoamer, using an organosilicon formulation, specifically MOMENTIVE® Silbreak 638; 0.15 wt% corrosion inhibitor, using a diimidazole formulation, specifically PC-HS antiemulsification corrosion inhibitor; and the remainder is solvent, which is a mixture of ethylene glycol monobutyl ether and ethanol in a 2:1 weight ratio.

[0044] The defoamer, corrosion inhibitor and solvent are premixed, and then the hyperbranched demulsifier is added and mixed evenly. The demulsifier is obtained by vacuum degassing.

[0045] Example 3: Preparation of a high-efficiency demulsifier for oilfield use. The specific implementation method is as follows:

[0046] I. Preparation of Hyperbranching Demulsifying Agent

[0047] Step A1: Premix dipropylene glycol and anhydrous tetrahydrofuran, purge with dry nitrogen gas and add potassium carbonate and anhydrous magnesium sulfate, mix, control the temperature in an ice-water bath at 5°C, slowly add methacryloyl chloride and stir for 7 hours. The ratio of dipropylene glycol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 17 g: 3 g: 650 mL. After the reaction is complete, filter to remove salt and rotary evaporate to recover tetrahydrofuran to obtain a semi-esterified intermediate.

[0048] Step A2: Take the semi-esterification intermediate, glycerol triglycidyl ether and toluene, premix them, then add triethylamine and triphenylphosphine and mix them. Under nitrogen protection, heat to 100℃ and stir and reflux for 3 hours. The ratio of semi-esterification intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1mol:80mmol:6mL:20mg:300mL. After the reaction is completed, remove and recover toluene by rotary evaporation under reduced pressure to obtain the hyperbranched matrix.

[0049] Step A3: Mix the hyperbranched matrix, hexadecyl mercaptan, photoinitiator, and dimethylformamide thoroughly at room temperature with 25 mW / cm 2 The mixture was subjected to ultraviolet irradiation and stirred for 14 hours. The ratio of hyperbranched matrix, hexadecyl mercaptan, photoinitiator and dimethylformamide was 50 g: 120 mmol: 0.16 g: 200 mL. After the reaction was completed, deionized water was added for washing, the aqueous phase was separated by centrifugation, and then vacuum dried to obtain the hyperbranched demulsifier.

[0050] II. Preparation of Demulsifier

[0051] The ingredients are prepared according to the following weight percentages: 41 wt% hyperbranching demulsifier, prepared in this embodiment; 1.7 wt% defoamer, using an organosilicon formulation, specifically MOMENTIVE® Silbreak 638; 0.18 wt% corrosion inhibitor, using a diimidazole formulation, specifically PC-HS antiemulsification corrosion inhibitor; and the remainder is solvent, which is a mixture of ethylene glycol monobutyl ether and ethanol in a 2:1 weight ratio.

[0052] The defoamer, corrosion inhibitor and solvent are premixed, and then the hyperbranched demulsifier is added and mixed evenly. The demulsifier is obtained by vacuum degassing.

[0053] Example 4: Preparation of a high-efficiency demulsifier for oilfield use. The specific implementation method is as follows:

[0054] I. Preparation of Hyperbranching Demulsifying Agent

[0055] Step A1: Premix dipropylene glycol and anhydrous tetrahydrofuran, purge with dry nitrogen gas and add potassium carbonate and anhydrous magnesium sulfate, mix, control the temperature in an ice-water bath at 5°C, slowly add methacryloyl chloride and stir for 7.5 h. The ratio of dipropylene glycol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 17 g: 4 g: 700 mL. After the reaction is complete, filter to remove salt and rotary evaporate to recover tetrahydrofuran to obtain a semi-esterified intermediate.

[0056] Step A2: Take the semi-esterification intermediate, glycerol triglycidyl ether and toluene, premix them, then add triethylamine and triphenylphosphine and mix them. Under nitrogen protection, heat to 95°C and stir and reflux for 3.3 h. The ratio of semi-esterification intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1 mol: 80 mmol: 5.5 mL: 20 mg: 280 mL. After the reaction is completed, remove and recover toluene by rotary evaporation under reduced pressure to obtain the hyperbranched matrix.

[0057] Step A3: Mix the hyperbranched matrix, hexadecyl mercaptan, photoinitiator, and dimethylformamide thoroughly at room temperature with 20 mW / cm 2 The mixture was subjected to ultraviolet irradiation and stirred for 15 hours. The ratio of hyperbranched matrix, hexadecyl mercaptan, photoinitiator and dimethylformamide was 50 g: 110 mmol: 0.15 g: 180 mL. After the reaction was completed, deionized water was added for washing, the aqueous phase was separated by centrifugation, and then vacuum dried to obtain the hyperbranched demulsifier.

[0058] II. Preparation of Demulsifier

[0059] The ingredients are prepared according to the following weight percentages: 42 wt% hyperbranching demulsifier, prepared in this embodiment; 1.5 wt% defoamer, using an organosilicon formulation, specifically MOMENTIVE® Silbreak 638; 0.18 wt% corrosion inhibitor, using a diimidazole formulation, specifically PC-HS antiemulsification corrosion inhibitor; the remainder is solvent, which is a mixture of ethylene glycol monobutyl ether and ethanol in a 2:1 weight ratio.

[0060] The defoamer, corrosion inhibitor and solvent are premixed, and then the hyperbranched demulsifier is added and mixed evenly. The demulsifier is obtained by vacuum degassing.

[0061] Comparative Example 1: SP-169, a demulsifier, was used to replace the hyperbranched demulsifier in Example 4 in an equal amount, while the rest of the implementation process was exactly the same.

[0062] Comparative Example 2 uses ZD-DML demulsifier to replace the hyperbranched demulsifier in Example 4 in equal amounts, and the rest of the implementation process is exactly the same.

[0063] To minimize the impact of the differences in crude oil displaced fluids on the experimental structure, crude oil emulsions were prepared by self-simulation. The specific method was as follows: 0.5 wt% of emulsifier OP-10 was added to water to prepare an aqueous phase, and 0.3 wt% of emulsifier Tween-20 was added to dehydrated crude oil to prepare an oil phase. The aqueous phase was added to the oil phase and sheared at 5000 rpm to obtain emulsion samples with water contents of 30 wt%, 60 wt%, and 80 wt%, respectively.

[0064] Referring to the SY / T 5281-2000 standard, the amount of demulsifier added was 150 mg / L. The dehydration rate η was tested at room temperature for 2 hours. The time to reach 80% dehydration rate was characterized as the dehydration rate T. The specific test results are shown in Tables 1-3.

[0065] Table 1. Demulsification test results at 30 wt% moisture content

[0066]

[0067] Table 2. Demulsification test results at 60 wt% moisture content

[0068]

[0069] Table 3. Demulsification test results at 80 wt% moisture content

[0070]

[0071] As can be seen from the data in Tables 1-3, the demulsifier prepared in the examples has high efficiency and deep demulsification ability, and exhibits stable demulsification effect at water contents of 30-80wt%.

[0072] In the description of this specification, the references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0073] The above description is merely an example and illustration of the present invention. Those skilled in the art can make various modifications or additions to the specific embodiments described, or use similar methods to replace them, as long as they do not deviate from the invention or exceed the scope defined in the claims, all of which should fall within the protection scope of the present invention.

Claims

1. A high-efficiency demulsifier for oilfield use, characterized in that, The specific components are: 37-42 wt% hyperbranching demulsifier, 1.5-2.0 wt% defoamer, and 0.12-0.18 wt% corrosion inhibitor, with the balance being solvent; The hyperbranched demulsifier is prepared by the following method: Step A1: Premix dipropylene glycol and anhydrous tetrahydrofuran, introduce dry nitrogen gas and add potassium carbonate and anhydrous magnesium sulfate, mix, control the temperature in an ice-water bath at 0-10℃, slowly add methacrylamide chloride and stir for 6-8 hours to prepare a semi-esterified intermediate. Step A2: Premix the semi-esterified intermediate, glycerol triglycidyl ether and toluene, then add triethylamine and triphenylphosphine and mix. Under nitrogen protection, heat to 90-100℃ and stir under reflux for 2.5-3.3 hours to prepare a hyperbranched matrix. Step A3: Mix the hyperbranched matrix, alkyl thiol, photoinitiator, and dimethylformamide thoroughly at room temperature with an induction rate of 20-25 mW / cm². 2 The mixture is subjected to ultraviolet irradiation and stirred for 10-15 hours to prepare a hyperbranched demulsifier.

2. The high-efficiency demulsifier for oilfield use according to claim 1, characterized in that, The ratio of dimeric glycerol, methacryloyl chloride, potassium carbonate, anhydrous magnesium sulfate, and anhydrous tetrahydrofuran is 0.1 mol: 0.2 mol: 15-18 g: 3-4 g: 550-700 mL.

3. The high-efficiency demulsifier for oilfield use according to claim 2, characterized in that, The ratio of the semi-esterified intermediate, glycerol triglycidyl ether, triethylamine, triphenylphosphine and toluene is 0.1 mol: 70-80 mmol: 4.5-6 mL: 15-20 mg: 220-300 mL.

4. The high-efficiency demulsifier for oilfield use according to claim 3, characterized in that, The ratio of hyperbranched matrix, alkyl thiol, photoinitiator and dimethylformamide is 50g: 80-120mmol: 0.12-0.16g: 150-200mL.

5. The high-efficiency demulsifier for oilfield use according to claim 4, characterized in that, Alkyl thiols are one of dodecyl thiols and hexadecyl thiols.

6. The high-efficiency demulsifier for oilfield use according to claim 1, characterized in that, The defoamer is an organosilicon preparation.

7. The high-efficiency demulsifier for oilfield use according to claim 1, characterized in that, The corrosion inhibitor is a diimidazole preparation.

8. A method for preparing a high-efficiency demulsifier for oilfield use according to any one of claims 1-7, characterized in that, Specifically, the defoamer, corrosion inhibitor and solvent are premixed, then hyperbranched demulsifier is added and mixed evenly, and defoamed under vacuum to obtain the demulsifier.

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