A method for preparing a solid phase crude oil demulsifier

Abstract

The application belongs to the technical field of oil field chemistry, and particularly relates to a preparation method of a solid-phase crude oil demulsifier. The preparation method is as follows: methyl anthranilate and a catalyst are added into a high-pressure reaction kettle, vacuum is drawn, propylene oxide is added, stirring and heating are performed, heating is stopped, temperature is maintained, cooling is performed, and stirring is stopped; ethylene oxide is introduced into the high-pressure reaction kettle, stirring is started, temperature is increased, heating is stopped, temperature is maintained, cooling is performed, and stirring is stopped; acetyl chloride is introduced into the high-pressure reaction kettle, stirring is started, temperature is maintained, the high-pressure reaction kettle is opened, the catalyst is slowly added, pH is maintained at 7-8, and the change of pH is stopped; and the mixture in the reaction kettle is subjected to pressure reduction and dehydration to obtain a product. The demulsifier has the characteristics of simple synthesis process and high demulsification rate.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of oil field chemistry, and particularly relates to a preparation method of a solid-phase-containing crude oil demulsifier. BACKGROUND

[0002] At present, the use of polymer flooding, surfactant flooding, and ternary compound flooding and other oil production technologies has improved the oil production amount, but due to the interaction of polymers, surfactants, water, and insoluble particles in the produced liquid, the produced liquid becomes a complex oil-water system, and it is of great significance to treat these seriously emulsified oil-water systems.

[0003] The separated water after treatment is used for recycling, and if the recycled water contains a large amount of crude oil, the water will cause the plugging of the injection well, reduce the pore permeability of the oil layer, hinder the water injection for oil production, cause the injection pressure to rise, and harm the formation, which seriously affects the recovery rate and directly affects the crude oil production.

[0004] The most difficult to treat is the emulsified oil in the produced water, and the commonly used method in production is to add a demulsifier during the oil-water separation stage of the crude oil produced liquid to accelerate the demulsification of the crude oil produced liquid and the oil removal rate of the sewage. There are many conventional demulsifiers, mainly including cationic organic high molecular condensate (such as polydimethyl diallyl ammonium chloride, epoxy chloropropane-fatty amine, etc.), non-ionic organic high molecular condensate (such as epoxy ethane-epoxy propane series), and the use of these agents leads to a high oil content in the lower layer of water after demulsification, which increases the cost and difficulty of the later sewage treatment system. Therefore, it is of great significance to study a high-efficiency demulsifier for treating oilfield produced liquid for oilfield production.

[0005] CN101113028A discloses a preparation method of a demulsification purifier, which is characterized by being composed of the following raw materials in percentage by weight: sewage 2%-68%, polymeric ferric sulfate 2%-37%, polymeric aluminum chloride 5%-45%, anhydrous calcium chloride 6%-57%, and ferric chloride 19%-47%; the preparation method is as follows: the sewage, polymeric ferric sulfate, and polymeric aluminum chloride are put into a stirrer, then the anhydrous calcium chloride is poured in and 50% water of the total amount of the four raw materials is added, and the mixture is fully stirred at a speed of 60 revolutions per minute to ensure that the solid components are completely dissolved, and the time is maintained for 2-3 hours; then the ferric chloride is added and the stirring is continued at a speed of 50-80 revolutions per minute for 0.5-1 hour, and after stopping for 6-10 hours, the mixture is filtered and filled into product packaging barrels. The advantage of the present application is that the sewage treatment effect is good and the investment is small. However, the dosage of the agent is 300-500 mg / L when used, which not only increases the production cost, but also produces a large amount of dregs, and in addition, the introduction of a large amount of soluble inorganic salts into the water also causes secondary pollution.

[0006] CN109628139A discloses a preparation method of a reverse demulsifier for thick oil production liquid treatment. The preparation method first prepares a fatty alcohol polyoxypropylene-oxirane ether by reacting a fatty alcohol with propylene oxide and ethylene oxide as a starting agent, then reacts with 2-bromoisobutyryl bromide to prepare 2-bromoisobutyrate, and finally reacts with an organic amine to prepare a brown viscous liquid. The reverse demulsifier prepared by the preparation method is a cationic polymer, which is a brown viscous liquid, and the rotary viscosity is 220-300 cp at 25℃ and a rotation speed of 100 r / min. When used for thick oil production liquid treatment, it can quickly increase the demulsification and coalescence speed of oil droplets in the thick oil production liquid, reduce the intermediate emulsion layer in oil-water separation, and improve the oil-water separation effect of the oil-water separator. However, the preparation process of the agent uses pyridine, which is a toxic substance and can cause harm to the human body and the environment, making it difficult to be industrialized. SUMMARY

[0007] The present application provides a solid-phase crude oil demulsifier and a preparation method thereof to overcome the deficiencies of the prior art. The demulsifier has the characteristics of simple synthesis process and high demulsification rate.

[0008] One of the purposes of the present application is to disclose a solid-phase crude oil demulsifier. The molecular formula of the solid-phase crude oil demulsifier is as follows:

[0009]

[0010] Wherein:

[0011] m and n are natural numbers of 2-20, more preferably natural numbers of 5-10;

[0012] x and y are natural numbers of 5-100, more preferably natural numbers of 20-50.

[0013] Another purpose of the present application is to provide a preparation method of the above-mentioned solid-phase crude oil demulsifier. The specific steps of the preparation method are as follows:

[0014] (1) Add methyl o-aminobenzoate and a catalyst to a high-pressure reaction kettle, purge the pipeline and the reaction kettle with nitrogen for 5-10 min, vacuumize, add propylene oxide, heat while stirring, raise the temperature to 180-190℃, stop heating, keep the temperature, cool to 85-90℃, and stop stirring;

[0015] (2) Introduce ethylene oxide into the high-pressure reaction kettle at a speed of 2-3 ml / min, after the introduction is completed, start stirring, and raise the temperature to 190-200℃, stop heating, keep the temperature, cool to 45℃, and stop stirring;

[0016] (3) acetyl chloride is introduced into the high-pressure reaction kettle at a speed of 2-3 ml / min, after the introduction is completed, stirring is started, and the reaction is kept warm, the high-pressure reaction kettle is opened, the catalyst is slowly added, and pH is maintained at 7-8 until the pH no longer changes;

[0017] (4) the mixture in the reaction kettle is subjected to vacuum dehydration to obtain the product demulsifier.

[0018] In the present application, preferably, based on 1 mol of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride are 4-40, 10-100 and 0.9-1.2 mol, respectively; more preferably, based on 1 mol of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride are 10-40, 40-100 and 1-1.1 mol, respectively.

[0019] In the present application, preferably, the catalyst in step (1) is sodium hydroxide or potassium hydroxide particles, and the weight ratio of the catalyst to methyl anthranilate is 0.2-0.3:1.

[0020] In the present application, preferably, the reaction keeping warm time in step (1) is 2-4 h; more preferably, the reaction keeping warm time is 2-3 h.

[0021] In the present application, preferably, the reaction keeping warm time in step (2) is 2-6 h; more preferably, the reaction keeping warm time is 3-4 h.

[0022] In the present application, preferably, the stirring speed in step (2) is 200-300 rpm.

[0023] In the present application, preferably, the reaction keeping warm time in step (3) is 1-2 h; more preferably, the reaction keeping warm time is 1-1.5 h.

[0024] In the present application, preferably, the stirring speed in step (3) is 200-300 rpm.

[0025] In the present application, preferably, the catalyst in step (3) is sodium hydroxide or potassium hydroxide particles.

[0026] The preparation reaction equation of the solid-phase-containing crude oil demulsifier is as follows:

[0027]

[0028]

[0029]

[0030] The solid-phase crude oil demulsifier of this invention belongs to the urethane ether type and is a macromolecular surfactant. A large amount of anionic surfactants are used in crude oil extraction. The tertiary amine in the molecule of this invention has a certain positive charge, neutralizing the negatively charged oil droplets, causing them to lose their repulsive effect and aggregate, reducing the stability of the interfacial film and achieving oil-water separation. The polyether segment in the molecule of this invention can capture a large number of oil droplets, increasing the chance of collision with the anions in the molecule and crude oil, neutralizing the surface charge of the oil droplets, disrupting the stability of the original emulsion, and achieving oil-water separation. The molecules of this invention can enter the oil-water interface, replacing the highly emulsifying surfactant, displacing surfactant molecules and other surface-active substances, destroying the emulsifying ability of oil droplets, making it easier for small oil droplets to aggregate, and achieving oil-water separation.

[0031] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0032] (1) The raw materials for the solid-phase crude oil demulsifier of the present invention are widely available and inexpensive, the synthesis process is simple, there are no by-products, and it is easy to industrialize;

[0033] (2) The solid-phase crude oil demulsifier of the present invention has a good demulsification effect. When the dosage is 100mg / L, the oil removal rate reaches more than 98%. Detailed Implementation

[0034] The present invention will now be described in further detail with reference to specific embodiments and data. It should be understood that these embodiments are merely illustrative of the invention and are not intended to limit the scope of the invention in any way.

[0035] Example 1

[0036] (1) Add 1 mol of methyl anthranilate and 30.2 g of sodium hydroxide to the high-pressure reactor, purge the pipeline and reactor with nitrogen for 5 min, evacuate, add 4 mol of propylene oxide, stir and heat, raise the temperature to 180°C, stop heating, keep the reaction at the temperature for 2 h, cool to 85°C, and stop stirring.

[0037] (2) 10 mol of ethylene oxide was introduced into the high-pressure reactor at a rate of 2 ml / min. After the introduction was completed, the stirring was started at a speed of 200 rpm. At the same time, the temperature was raised to 190°C. The heating was stopped, and the reaction was kept at the temperature for 2 hours. The temperature was then cooled to 45°C and the stirring was stopped.

[0038] (3) 0.9 mol of acetyl chloride was introduced into the high-pressure reactor at a rate of 2 ml / min. After the introduction was completed, the stirring was turned on at a speed of 300 rpm. The reaction was kept at a constant temperature for 1 h. The high-pressure reactor was then opened and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed.

[0039] (4) The mixture in the reaction kettle is dehydrated under reduced pressure to obtain the product demulsifier.

[0040] Example 2

[0041] (1) In a high-pressure reaction kettle, 1 mol of methyl o-aminobenzoate and 33.4 g of sodium hydroxide are added, the pipeline and the reaction kettle are purged with nitrogen for 10 min, vacuum is applied, 8 mol of propylene oxide is added, stirring is performed while heating, the temperature is raised to 190°C, heating is stopped, and the reaction is maintained for 2 h, the temperature is cooled to 90°C, and stirring is stopped;

[0042] (2) 50 mol of ethylene oxide is introduced into the above high-pressure reaction kettle at a rate of 2 ml / min, after the introduction is completed, stirring is started at a speed of 200 rpm, the temperature is raised to 200°C, heating is stopped, the reaction is maintained for 4 h, the temperature is cooled to 45°C, and stirring is stopped;

[0043] (3) 1.2 mol of acetyl chloride is introduced into the above high-pressure reaction kettle at a rate of 3 ml / min, after the introduction is completed, stirring is started at a speed of 300 rpm, the reaction is maintained for 1 h, the high-pressure reaction kettle is opened, sodium hydroxide is slowly added, and the pH is maintained at 7-8 until the pH no longer changes;

[0044] (4) The mixture in the reaction kettle is dehydrated under reduced pressure to obtain the product demulsifier.

[0045] Example 3

[0046] (1) In a high-pressure reaction kettle, 1 mol of methyl o-aminobenzoate and 37.8 g of sodium hydroxide are added, the pipeline and the reaction kettle are purged with nitrogen for 6 min, vacuum is applied, 10 mol of propylene oxide is added, stirring is performed while heating, the temperature is raised to 185°C, heating is stopped, and the reaction is maintained for 2 h, the temperature is cooled to 86°C, and stirring is stopped;

[0047] (2) 60 mol of ethylene oxide is introduced into the above high-pressure reaction kettle at a rate of 3 ml / min, after the introduction is completed, stirring is started at a speed of 250 rpm, the temperature is raised to 195°C, heating is stopped, the reaction is maintained for 4 h, the temperature is cooled to 45°C, and stirring is stopped;

[0048] (3) 0.95 mol of acetyl chloride is introduced into the above high-pressure reaction kettle at a rate of 2 ml / min, after the introduction is completed, stirring is started at a speed of 250 rpm, the reaction is maintained for 1 h, the high-pressure reaction kettle is opened, sodium hydroxide is slowly added, and the pH is maintained at 7-8 until the pH no longer changes;

[0049] (4) The mixture in the reaction kettle is dehydrated under reduced pressure to obtain the product demulsifier.

[0050] Example 4

[0051] (1) In a high-pressure reactor, 1 mol of methyl o-aminobenzoate and 35.2 g of sodium hydroxide were added, the pipeline and the reactor were purged with nitrogen for 7 min, vacuumized, 18 mol of propylene oxide was added, heated while stirring, the temperature was raised to 182°C, heating was stopped, and the reaction was maintained for 2 h at constant temperature, and then the stirring was stopped when the temperature was cooled to 87°C;

[0052] (2) 40 mol of ethylene oxide was introduced into the above high-pressure reactor at a speed of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 220 rpm, and the temperature was raised to 192°C, heating was stopped, and the reaction was maintained for 3 h at constant temperature, and then the stirring was stopped when the temperature was cooled to 45°C;

[0053] (3) 1.1 mol of acetyl chloride was introduced into the above high-pressure reactor at a speed of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 300 rpm, and the reaction was maintained for 1 h at constant temperature, the high-pressure reactor was opened, and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed;

[0054] (4) The mixture in the reactor was dehydrated under reduced pressure to obtain the product demulsifier.

[0055] Example 5

[0056] (1) In a high-pressure reactor, 1 mol of methyl o-aminobenzoate and 35.7 g of potassium hydroxide were added, the pipeline and the reactor were purged with nitrogen for 8 min, vacuumized, 26 mol of propylene oxide was added, heated while stirring, the temperature was raised to 185°C, heating was stopped, and the reaction was maintained for 3 h at constant temperature, and then the stirring was stopped when the temperature was cooled to 88°C;

[0057] (2) 20 mol of ethylene oxide was introduced into the above high-pressure reactor at a speed of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 300 rpm, and the temperature was raised to 197°C, heating was stopped, and the reaction was maintained for 3 h at constant temperature, and then the stirring was stopped when the temperature was cooled to 45°C;

[0058] (3) 1.05 mol of acetyl chloride was introduced into the above high-pressure reactor at a speed of 2 ml / min, after the introduction was completed, the stirring was started at a speed of 300 rpm, and the reaction was maintained for 2 h at constant temperature, the high-pressure reactor was opened, and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed;

[0059] (4) The mixture in the reactor was dehydrated under reduced pressure to obtain the product demulsifier.

[0060] Example 6

[0061] (1) In a high-pressure reactor, 1 mol of methyl o-aminobenzoate and 38.9 g of potassium hydroxide were added, the pipeline and the reactor were purged with nitrogen for 5 min, vacuumized, 30 mol of propylene oxide was added, heated while stirring, the temperature was raised to 187°C, heating was stopped, and the reaction was kept for 3 h, the stirring was stopped after cooling to 89°C;

[0062] (2) 70 mol of ethylene oxide was introduced into the high-pressure reactor at a rate of 2 ml / min, after the introduction was completed, the stirring was started at a speed of 300 rpm, and the temperature was raised to 198°C, heating was stopped, and the reaction was kept for 5 h, the stirring was stopped after cooling to 45°C;

[0063] (3) 1 mol of acetyl chloride was introduced into the above high-pressure reactor at a rate of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 250 rpm, and the reaction was kept for 2 h, the high-pressure reactor was opened, and potassium hydroxide was slowly added to maintain pH 7-8 until the pH no longer changed;

[0064] (4) The mixture in the reactor was dehydrated under reduced pressure to obtain the product demulsifier.

[0065] Example 7

[0066] (1) In a high-pressure reactor, 1 mol of methyl o-aminobenzoate and 41.4 g of potassium hydroxide were added, the pipeline and the reactor were purged with nitrogen for 9 min, vacuumized, 35 mol of propylene oxide was added, heated while stirring, the temperature was raised to 183°C, heating was stopped, and the reaction was kept for 4 h, the stirring was stopped after cooling to 85°C;

[0067] (2) 80 mol of ethylene oxide was introduced into the above high-pressure reactor at a rate of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 280 rpm, and the temperature was raised to 195°C, heating was stopped, and the reaction was kept for 6 h, the stirring was stopped after cooling to 45°C;

[0068] (3) 1 mol of acetyl chloride was introduced into the above high-pressure reactor at a rate of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 220 rpm, and the reaction was kept for 2 h, the high-pressure reactor was opened, and potassium hydroxide was slowly added to maintain pH 7-8 until the pH no longer changed;

[0069] (4) The mixture in the reactor was dehydrated under reduced pressure to obtain the product demulsifier.

[0070] Example 8

[0071] (1) in the high pressure reactor, 1 mol of methyl o-aminobenzoate and 45.3 g of potassium hydroxide were added, the pipeline and the reactor were purged with nitrogen for 10 min, vacuumized, 40 mol of propylene oxide was added, heated while stirring, the temperature was raised to 188 ℃, heating was stopped, and the reaction was kept for 4 h, the temperature was cooled to 90 ℃, and the stirring was stopped;

[0072] (2) 100 mol of ethylene oxide was introduced into the above high pressure reactor at a speed of 2 ml / min, after the introduction was completed, the stirring was started at a speed of 230 rpm, the temperature was raised to 196 ℃, heating was stopped, the reaction was kept for 6 h, the temperature was cooled to 45 ℃, and the stirring was stopped;

[0073] (3) 1.05 mol of acetyl chloride was introduced into the above high pressure reactor at a speed of 3 ml / min, after the introduction was completed, the stirring was started at a speed of 220 rpm, the reaction was kept for 2 h, the high pressure reactor was opened, and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed;

[0074] (4) the mixture in the reactor was dehydrated under reduced pressure to obtain the product demulsifier.

[0075] Test Example 1: Indoor evaluation of demulsifier

[0076] The emulsion at the oil-water separation interface of a certain joint station in Shengli oilfield was taken, the oil content was 9500 mg / L, at a temperature of 60 ℃, the performance of the demulsifier (Examples 1-8) of the application was evaluated according to SY / T 5797-1993 "Method for evaluating the performance of oil-in-water emulsion demulsifier", and the evaluation results are shown in Table 1.

[0077] Before use, the demulsifier was diluted with distilled water to a concentration of 1 wt%, and the demulsifier PR-23 (polyoxyethylene polyoxypropylene propylene glycol monoether) was used as a comparative experiment.

[0078] Table 1: Test results of demulsifier performance

[0079]

[0080] From Table 1, it can be seen that:

[0081] (1) when the concentration of the demulsifier (Examples 1-8) of the application was 50 mg / L, the oil removal rate reached more than 96%, and the highest reached 99.1%, while the comparative demulsifier PR-23 had an emulsion layer;

[0082] (2) when the concentration of the demulsifier (Examples 1-8) of the application was 100 mg / L, the oil removal rate reached more than 98%, and the highest reached 99.5%, while the oil removal rate of the comparative demulsifier PR-23 was 93%, which was significantly lower than that of the application.

[0083] Application Example 1: On-site application of demulsifier

[0084] The No. 7 oil tank of a certain union station in Shengli Oilfield separates the thermal recovery heavy oil, and the oil-water interface produces about 50 m 3 of oil-water emulsion liquid per day, with oil content of 12000 mg / L, which is treated by demulsification with the demulsifier of Example 7 of the present application, with a use concentration of 100 mg / L, and the oil content of the oil-water emulsion liquid after treatment is reduced to 90 mg / L, with an oil removal rate of 99.2%, reaching the process requirements.

[0085] The preferred embodiments of the present application are described in detail above, but the present application is not limited thereto. Within the technical concept of the present application, various simple modifications can be made to the technical solutions of the present application, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be considered as disclosed by the present application, and all fall within the protection scope of the present application.

Claims

1. A method for preparing a solid phase-containing crude oil demulsifier, characterized by, The preparation method comprises the following steps: (1) adding methyl anthranilate and a catalyst into a high-pressure reaction kettle, purging the pipeline and the reaction kettle with nitrogen for 5-10 minutes, vacuumizing, adding propylene oxide, stirring and heating, increasing the temperature to 180-190°C, stopping heating, keeping the temperature, keeping the reaction for 2-4 hours, cooling to 85-90°C, and stopping stirring; the catalyst is sodium hydroxide or potassium hydroxide particles, and the weight ratio of the catalyst to methyl anthranilate is 0.2-0.3:1; (2) introducing ethylene oxide into the high-pressure reaction kettle at a speed of 2-3 ml / min, after the introduction is completed, starting stirring, increasing the temperature to 190-200°C, stopping heating, keeping the temperature, keeping the reaction for 2-6 hours, cooling to 45°C, and stopping stirring; (3) introducing acetyl chloride into the high-pressure reaction kettle at a speed of 2-3 ml / min, after the introduction is completed, starting stirring, keeping the temperature, keeping the reaction for 1-2 hours, opening the high-pressure reaction kettle, slowly adding the catalyst, maintaining pH 7-8, and until the pH no longer changes; based on 1 mole of methyl anthranilate; (4) performing vacuum dehydration on the mixture in the reaction kettle to obtain a product demulsifier; Based on 1 mole of methyl anthranilate, the amount of propylene oxide, ethylene oxide and acetyl chloride is 4-40, 10-100 and 0.9-1.2 moles, respectively; The molecular formula of the demulsifier is as follows: Wherein: m and n are natural numbers of 2-20; x and y are natural numbers of 5-100.

2. A solid-phase crude oil demulsifier containing prepared by the preparation method in claim 1.

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