Anti-emulsion demulsifier for oil field as well as preparation method and application of anti-emulsion demulsifier

Abstract

The invention belongs to the technical field of oil exploitation, and particularly relates to an anti-emulsion demulsifier for an oil field as well as a preparation method and application of the anti-emulsion demulsifier. The preparation method comprises the following steps: sequentially adding 3-chloro-2, 2-dichloromethyl-1-alcohol and sodium hydroxide into a high-pressure reaction kettle, introducing epoxypropane when the temperature reaches 90-95 DEG C, heating to 130-170 DEG C, and carrying out heat preservation reaction; slowly introducing ethylene oxide, heating to 140-180 DEG C after the ethylene oxide is completely introduced, gradually reducing the pressure along with the proceeding of the reaction, stopping the reaction when the pressure is not reduced any more, and cooling the reaction system to below 50 DEG C; and adding ethanol, stirring and dissolving, transferring into a four-neck flask, adding diethylenetriamine propyl trimethoxy silane, heating and refluxing, adjusting the pH to 7-8 by using hydrochloric acid, and carrying out reduced pressure distillation to obtain a viscous liquid, namely the demulsifier product. The anti-emulsion demulsifier for the oil field has the characteristics of simple synthesis process, high anti-emulsion rate and high oil removal rate.

Description

Technical Field

[0001] The invention belongs to the technical field of oil extraction, and in particular relates to an anti-emulsification and demulsification agent for oil fields and a preparation method and application thereof. Background Art

[0002] With the continuous exploitation of crude oil, the water content of crude oil in oil well produced fluid gradually increases. During the exploitation, transportation and processing of crude oil, the oil-water mixture passes through the fuel injection nozzle, gathering pipeline and other links, and due to shearing and stirring, it is easy to form a stable oil-water emulsion.

[0003] The difficulty of handling this type of emulsion is also increasing. The quality of produced fluid is becoming more and more complex, showing characteristics such as high mineralization, high oil emulsification, high small particle suspended matter, high polymer content, high bacterial content, and high corrosion rate. In addition, the difference in density between oil and water is small and the phase state is stable, making oil-water separation difficult.

[0004] Traditional demulsifiers are not effective in treating the increasingly complex crude oil produced fluids. Water quality problems after demulsification: After demulsification, some demulsifiers have a high oil content in the lower water layer, which not only increases the cost and difficulty of the sewage treatment system, but may also have a certain impact on the environment. Low oil removal rate and incomplete demulsification effect: Some demulsifiers have the disadvantages of low oil removal rate and incomplete demulsification effect, which cannot meet the high requirements of produced water treatment and affect the production efficiency and economic benefits of the oil field.

[0005] CN104176788B discloses a degreasing agent for wastewater produced by binary composite flooding in oil fields and a preparation method thereof. The degreasing agent comprises acryloyloxyethyl dimethylamine, chloroalkane, acrylamide, N,N'-methylenebisacrylamide, ammonium persulfate and sodium sulfite. The preparation method of the degreasing agent is as follows: react acryloyloxyethyl dimethylamine with chloroalkane to generate a cationic monomer; mix acrylamide and N,N'-methylenebisacrylamide, add them to deionized water three times, stir while adding, add the prepared cationic monomer after complete dissolution, and then add ammonium persulfate and sodium sulfite solution respectively, stir and react at a constant temperature of 45°C for 3h to 5h to obtain the degreasing agent. The field test concentration of the degreasing agent of the invention is 60mg / L, and the oil content still remains 68.2mg / L after treatment, and the demulsification and oil removal efficiency needs to be improved.

[0006] CN101113028A discloses a demulsifying purifier, which is composed of the following raw materials in percentage by weight: 2% to 68% of sewage, 2% to 37% of polyferric sulfate, 5% to 45% of polyaluminium chloride, 6% to 57% of anhydrous calcium chloride, and 19% to 47% of ferric chloride; its preparation method is: put sewage, polyferric sulfate and polyaluminium chloride into a mixer, then pour in anhydrous calcium chloride and add 50% of water of the sum of the four raw materials, stir fully, stir at a speed of 60 revolutions per minute, ensure that the solid components are completely dissolved, and keep for 2-3 hours; then add ferric chloride and continue stirring, stirring at a speed of 50-80 revolutions per minute, for 0.5-1 hour, stop the machine for 6-10 hours, filter and pack into the product packaging barrel. The dosage of the agent is 300-500mg / L when used. Such a large dosage not only increases the production cost, but also produces a large amount of scum, and introduces a large amount of soluble inorganic salts into the water body, which also causes secondary pollution. Summary of the invention

[0007] The present invention aims at the deficiencies of the current prior art and provides an anti-emulsification and demulsification agent for oil fields and its preparation method and application. The anti-emulsification and demulsification agent for oil fields of the present invention has the characteristics of simple synthesis process, high anti-emulsification rate and high oil removal rate.

[0008] In order to achieve the above objectives:

[0009] In a first aspect, the present invention discloses a method for preparing an anti-emulsification and demulsification agent for oil fields, and the specific steps of the preparation method are as follows:

[0010] (1) 3-chloro-2,2-dichloromethyl-1-ol and sodium hydroxide are sequentially added to a high-pressure reactor, the reactor is purged with nitrogen, and the temperature is raised while vacuuming. When the temperature reaches 90-95° C., vacuuming is stopped, propylene oxide is introduced, and the temperature is raised to 130-170° C. and kept for reaction; the reaction pressure gradually decreases, and when the pressure no longer decreases, ethylene oxide is slowly introduced. After the introduction is completed, the temperature is raised to 140-180° C., and the pressure gradually decreases as the reaction proceeds. When the pressure no longer decreases, the reaction is stopped, and the reaction system is cooled to below 50° C.;

[0011] (2) adding ethanol, stirring to dissolve, transferring to a four-necked flask, adding diethylenetriaminopropyltrimethoxysilane, heating to reflux, adjusting the pH to 7-8 with hydrochloric acid, and distilling off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0012] In the present invention, preferably, based on 1 mol part of 3-chloro-2,2-dichloromethyl-1-ol, the amounts of propylene oxide, ethylene oxide and diethylenetriaminopropyltrimethoxysilane are 5-20 mol parts, 10-40 mol parts and 2.5-3.5 mol parts respectively.

[0013] In the present invention, preferably, the mass ratio of sodium hydroxide to 3-chloro-2,2-dichloromethyl-1-ol in step (1) is 0.7-1:1.

[0014] In the present invention, preferably, the mass ratio of ethanol to 3-chloro-2,2-dichloromethyl-1-ol in step (2) is 40-100:1.

[0015] In the present invention, preferably, the heating reflux time in step (2) is 1-4h.

[0016] The synthetic reaction equation of the demulsifier for oil field of the present invention is:

[0017]

[0018]

[0019] In another aspect, the present invention discloses an anti-emulsification and demulsification agent for oil fields, wherein the molecular structure of the anti-emulsification and demulsification agent is as follows:

[0020]

[0021] Wherein, m is a positive integer of 5-20, and n is a positive integer of 10-40.

[0022] In a third aspect, the present invention discloses the use of the above-mentioned demulsifier in oil well produced fluid.

[0023] The oil field demulsifier of the present invention is a silicon-containing polyether demulsifier, which has excellent surface activity and can achieve efficient demulsification effect under harsh conditions. The lipophilic group is a siloxane and polyoxypropyl ether segment, and the hydrophilic group is a polyoxyethyl ether segment. Since the present invention has super strong interfacial activity, the molecule can enter the oil-water interface, replace the surfactant with strong emulsification, and can displace the surfactant molecules and other surface active substances in the oil droplets, destroy the emulsification ability of the oil droplets, thereby playing a demulsification effect. The polyether segment belongs to a linear structure, has high flexibility, and is prone to internal rotation of the molecular chain, sweeping and capturing tiny oil droplets, increasing the collision opportunity of the oil droplets, forming oil droplets that are easy to aggregate and float to achieve the purpose of demulsification. The present invention contains siloxane, which is not easily emulsified by general surfactants, and therefore has a good anti-emulsification effect.

[0024] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0025] (1) The oil field demulsifier of the present invention has a wide source of raw materials, low price and simple synthesis process;

[0026] (2) The demulsifier for oil fields of the present invention has a good demulsification effect. When the concentration is 20 mg / L, the demulsification rate reaches 98% or more, and the oil removal rate reaches 99% or more. DETAILED DESCRIPTION

[0027] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0028] The present invention will be further described below in conjunction with specific embodiments:

[0029] Example 1

[0030] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 5.36 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 90°C, the vacuuming was stopped, 0.2 mol of propylene oxide was introduced, and the temperature was raised to 140°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 0.4 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 150°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0031] (2) Add 306 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.1 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 1 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0032] Example 2

[0033] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 5.68 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 91°C, the vacuuming was stopped, 0.3 mol of propylene oxide was introduced, and the temperature was raised to 130°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 0.6 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 140°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0034] (2) Add 368 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.105 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 2 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0035] Example 3

[0036] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 5.96 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 95°C, the vacuuming was stopped, 0.4 mol of propylene oxide was introduced, and the temperature was raised to 140°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 0.8 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 150°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0037] (2) Add 400 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.14 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 2 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0038] Example 4

[0039] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 6.54 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 90°C, the vacuuming was stopped, 0.5 mol of propylene oxide was introduced, and the temperature was raised to 150°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 1 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 160°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0040] (2) Add 480 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.135 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 3 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0041] Example 5

[0042] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 6.96 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 92°C, the vacuuming was stopped, 0.6 mol of propylene oxide was introduced, and the temperature was raised to 160°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 1.2 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 170°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0043] (2) Add 576 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.11 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 3 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0044] Example 6

[0045] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 7.2 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 90°C, the vacuuming was stopped, 0.7 mol of propylene oxide was introduced, and the temperature was raised to 170°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 1.4 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 180°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0046] (2) Add 650 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.115 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 4 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0047] Example 7

[0048] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 7.58 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 93°C, the vacuuming was stopped, 0.7 mol of propylene oxide was introduced, and the temperature was raised to 170°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 1.6 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 180°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0049] (2) Add 706 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.125 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 4 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0050] Example 8

[0051] (1) 0.04 mol of 3-chloro-2,2-dichloromethyl-1-ol and 7.66 g of sodium hydroxide were added to a high-pressure reactor in sequence, the reactor was purged with nitrogen, and the temperature was raised while vacuuming. When the temperature reached 94°C, the vacuuming was stopped, 0.8 mol of propylene oxide was introduced, and the temperature was raised to 170°C and kept for reaction. The reaction pressure gradually decreased. When the pressure stopped decreasing, 1.6 mol of ethylene oxide was slowly introduced. After the introduction was completed, the temperature was raised to 180°C. As the reaction proceeded, the pressure gradually decreased. When the pressure stopped decreasing, the reaction was stopped and the reaction system was cooled to below 50°C.

[0052] (2) Add 766 g of ethanol, stir to dissolve, transfer to a four-necked flask, add 0.12 mol of diethylenetriaminopropyltrimethoxysilane, heat and reflux for 4 h, adjust the pH to 7-8 with hydrochloric acid, and distill off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product.

[0053] Example 9 Test of anti-emulsification performance

[0054] Prepare simulated water: sodium chloride, 5000 mg / L; calcium chloride, 1000 mg / L; sodium carbonate, 200 mg / L; PAM, 50 mg / L; petroleum sulfonate, 500 mg / L.

[0055] 500 mL of simulated water was added to different beakers, and 10 mg / L and 20 mg / L of the demulsifier of the present invention were added, stirred evenly, and 10 ml of 10 wt% crude oil petroleum ether solution was added respectively, emulsified at a speed of 10000 rpm for 20 min, and allowed to stand for 6 h, while a blank was made.

[0056] The oil content of the lower water phase was tested, the demulsification rate was calculated, and a comparative experiment was conducted using Shandong Aike water treatment demulsifier OFC-609.

[0057] Oil content of lower aqueous phase: 450 mg / L.

[0058] The test results are shown in Table 1.

[0059] Table 1 Anti-emulsion energy test results

[0060]

[0061] From Table 1 we can see that:

[0062] (1) When the demulsifier of the present invention is used at a concentration of 10 mg / L, the demulsification rate is above 96%, with the highest reaching 98.27% (Example 8). The demulsification rate of the comparative Shandong Aike water treatment demulsifier OFC-609 is 87.78%, which is significantly lower than that of the present invention;

[0063] (2) When the demulsifier of the present invention is used at a concentration of 20 mg / L, the demulsification rate reaches 98% or more, and the highest reaches 99.02% (Example 8). The demulsification rate of the comparative Shandong Aike water treatment demulsifier OFC-609 is 92.22%, which is significantly lower than that of the present invention.

[0064] Example 10 Demulsification Performance Test

[0065] Experimental object: oil-containing produced water from an oil production plant in Shengli Oilfield, oil content: 1500mg / L.

[0066] 10mg / L and 20mg / L of the demulsifier of the present invention were added, and the demulsification performance was tested with reference to SY / T5281-2000 "Crude Oil Demulsifier Performance Testing Method", and the treatment time was 2min. Shandong Aike water treatment demulsifier OFC-609 was used for comparative experiments.

[0067] The test results are shown in Table 2.

[0068] Table 2 Demulsification performance test results

[0069]

[0070] From Table 2 we can see that:

[0071] (1) When the demulsifier of the present invention is used at a concentration of 10 mg / L, the oil removal rate reaches more than 98%, and the highest reaches 99.50% (Example 8). The oil removal rate of Shandong Aike water treatment demulsifier OFC-609 is 93.67%, which is significantly lower than that of the present invention;

[0072] (2) When the demulsifier of the present invention is used at a concentration of 20 mg / L, the oil removal rate reaches 99% or above, and the highest reaches 99.56% (Example 8). The oil removal rate of the comparative Shandong Aike water treatment demulsifier OFC-609 is 96.00%, which is significantly lower than that of the present invention.

[0073] The preferred embodiments of the present invention are described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0074] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0075] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A method for preparing an anti-emulsification and demulsification agent for oil fields, characterized in that: The specific steps of the preparation method are as follows: (1) 3-chloro-2,2-dichloromethyl-1-ol and sodium hydroxide are sequentially added to a high-pressure reactor, the reactor is purged with nitrogen, and the temperature is raised while vacuuming. When the temperature reaches 90-95° C., vacuuming is stopped, propylene oxide is introduced, and the temperature is raised to 130-170° C. and kept for reaction; the reaction pressure gradually decreases, and when the pressure no longer decreases, ethylene oxide is slowly introduced. After the introduction is completed, the temperature is raised to 140-180° C., and the pressure gradually decreases as the reaction proceeds. When the pressure no longer decreases, the reaction is stopped, and the reaction system is cooled to below 50° C.; (2) adding ethanol, stirring to dissolve, transferring to a four-necked flask, adding diethylenetriaminopropyltrimethoxysilane, heating to reflux, adjusting the pH to 7-8 with hydrochloric acid, and distilling off the solvent under reduced pressure to obtain a viscous liquid, i.e., a demulsifier product; Based on 1 mole of 3-chloro-2,2-dichloromethyl-1-ol, the amounts of propylene oxide, ethylene oxide and diethylenetriaminopropyltrimethoxysilane are 5-20 mole parts, 10-40 mole parts and 2.5-3.5 mole parts respectively.

2. The preparation method according to claim 1, characterized in that: The mass ratio of sodium hydroxide to 3-chloro-2,2-dichloromethyl-1-ol in step (1) is 0.7-1:

1.

3. The preparation method according to claim 1, characterized in that: The mass ratio of ethanol to 3-chloro-2,2-dichloromethyl-1-ol in step (2) is 40-100:

1.

4. The preparation method according to claim 1, characterized in that: The heating reflux time in step (2) is 1-4h.

5. An anti-emulsification and demulsification agent for oil fields, characterized in that: The molecular structural formula of the demulsifier is as follows: Wherein: m is a positive integer between 5 and 20; n is a positive integer from 10 to 40.

6. Use of the demulsifier and demulsifier according to claim 5 in oil well produced fluid.

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