Preparation method of solid-phase-containing crude oil demulsifier

Abstract

The invention belongs to the technical field of oilfield chemistry, and particularly relates to a preparation method of a solid-phase-containing crude oil demulsifier. The preparation method comprises the following steps: adding methyl anthranilate and a catalyst into a high-pressure reaction kettle, vacuumizing, adding epoxypropane, heating while stirring, heating, stopping heating, carrying out heat preservation reaction, cooling and stopping stirring; ethylene oxide is introduced into the high-pressure reaction kettle, stirring is started, meanwhile, heating is conducted, heating is stopped, a heat preservation reaction is conducted, cooling is conducted, and stirring is stopped; introducing acetyl chloride into the high-pressure reaction kettle, starting stirring and heat preservation reaction, opening the high-pressure reaction kettle, slowly adding a catalyst, and maintaining the pH value to be 7-8 until the pH value does not change any more; and dehydrating the mixture in the reaction kettle under reduced pressure to obtain the product. The demulsifier provided by the invention has the characteristics of simple synthesis process and high demulsification rate.

Description

Technical Field

[0001] The invention belongs to the technical field of oilfield chemistry, and in particular relates to a method for preparing a solid-phase crude oil demulsifier. Background Art

[0002] At present, the use of oil recovery technologies such as polymer drive, surfactant drive, and ternary composite drive has increased crude oil recovery. However, due to the interaction between polymers, surfactants, water, and insoluble particles in the produced fluid, the produced fluid becomes a complex oil-water system. It is of great significance to treat these severely emulsified oil-water systems.

[0003] The separated water after treatment is used for recycling. If the recycled water contains more crude oil and is directly injected back into the formation without treatment, it will cause blockage of the injection well, reduce the porosity and permeability of the oil layer, hinder water injection and oil production, increase the water injection pressure, and damage the formation, seriously affecting the recovery rate and directly affecting the crude oil production.

[0004] Emulsified oil in produced water is the most difficult to treat. The commonly used method in production is to add demulsifiers during the oil-water separation stage of crude oil produced liquid to accelerate the demulsification of crude oil produced liquid and the rate of oil removal from sewage. There are many types of conventional demulsifiers, mainly cationic organic polymer coagulants (such as polydimethyldiallyl ammonium chloride, epichlorohydrin-fatty amine, etc.) and non-ionic organic polymer coagulants (such as ethylene oxide-propylene oxide series). The use of these agents leads to high oil content in the lower layer of water after demulsification, which increases the cost and difficulty of the subsequent sewage treatment system. Therefore, the study of demulsifiers for efficient treatment of oilfield produced liquid is of great significance to oilfield production.

[0005] CN101113028A discloses a method for preparing a demulsifying purifier, characterized in that it is composed of the following raw materials in weight percentage: 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; the 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 half an hour to 1 hour, stop the machine for 6-10 hours, filter and pack into product packaging barrels. The invention has the advantages of good sewage treatment effect and small investment. However, the dosage of the agent is 300-500 mg / L. Such a large dosage not only increases the production cost, but also produces a large amount of scum. In addition, a large amount of soluble inorganic salts are introduced into the water body, causing secondary pollution.

[0006] CN109628139A discloses a method for preparing a reverse demulsifier for treating heavy oil produced liquid. The method first uses a fatty alcohol as an initiator to react with propylene oxide and ethylene oxide to prepare a fatty alcohol polyoxypropylene-oxyethylene ether, 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 obtained by the preparation method is a cationic polymer, which is a brown viscous liquid. The rotational viscosity is 220-300cp under the conditions of 25°C and a rotation speed of 100r / min. When used for the treatment of heavy oil produced liquid, it can quickly increase the speed of demulsification and aggregation of emulsified oil droplets of heavy oil produced liquid, reduce the intermediate emulsified layer of 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, which will cause harm to the human body and the environment and is difficult to industrialize. Summary of the invention

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

[0008] One of the purposes of the present invention is to disclose a demulsifier for crude oil containing a solid phase, and the molecular formula of the demulsifier for crude oil containing a solid phase is as follows: in: m and n are natural numbers of 2-20, more preferably natural numbers of 5-10; x and y are natural numbers of 5-100, more preferably 20-50.

[0009] Another object of the present invention is to provide a method for preparing the above-mentioned solid phase crude oil demulsifier, and the specific steps of the preparation method are as follows: (1) Add methyl anthranilate and a catalyst to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 5-10 minutes, evacuate, add propylene oxide, heat while stirring, raise the temperature to 180-190°C, stop heating, keep the temperature for reaction, cool to 85-90°C, and stop stirring; (2) Add ethylene oxide to the autoclave at a rate of 2-3 ml / min. After the addition is complete, start stirring and raise the temperature to 190-200°C. Stop heating, keep the temperature for reaction, cool to 45°C, and stop stirring. (3) Add acetyl chloride to the autoclave at a rate of 2-3 ml / min. After the addition is complete, start stirring, keep the reaction warm, open the autoclave, slowly add the catalyst, maintain the pH at 7-8, until the pH no longer changes; (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0010] In the present invention, preferably, based on 1 mole part of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride are 4-40, 10-100 and 0.9-1.2 mole parts respectively; more preferably, based on 1 mole part of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride are 10-40, 40-100 and 1-1.1 mole parts respectively.

[0011] In the present invention, 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.

[0012] In the present invention, preferably, the insulation reaction time in step (1) is 2-4 hours; more preferably, the insulation reaction time is 2-3 hours.

[0013] In the present invention, preferably, the insulation reaction time in step (2) is 2-6 hours; more preferably, the insulation reaction time is 3-4 hours.

[0014] In the present invention, preferably, the stirring speed in step (2) is 200-300 rpm.

[0015] In the present invention, preferably, the insulation reaction time in step (3) is 1-2 hours; more preferably, the insulation reaction time is 1-1.5 hours.

[0016] In the present invention, preferably, the stirring speed in step (3) is 200-300 rpm.

[0017] In the present invention, preferably, the catalyst in step (3) is sodium hydroxide or potassium hydroxide particles.

[0018] The preparation reaction equation of the solid phase crude oil demulsifier of the present invention is: The solid phase crude oil demulsifier of the present invention belongs to the amino ester ether type and belongs to the macromolecular surfactant. A large number of anionic surfactants are used in crude oil exploitation. The tertiary amine in the molecule of the present invention has a certain positive charge, neutralizes the negatively charged oil droplets, makes the oil droplets lose the repulsive effect and aggregate with each other, reduces the stability of the interface film, and achieves oil-water separation; the polyether segment in the molecule of the present invention can capture a large number of oil droplets, increase the collision opportunities with the anions in the present invention and crude oil, neutralize the electrical properties of the surface of the oil droplets, destroy the stability of the original emulsion, and achieve oil-water separation; the molecule of the present invention can enter the oil-water interface, replace the surfactant with strong emulsification, displace the surfactant molecules and other surface active substances, destroy the emulsification ability of the oil droplets, make it easier for small oil droplets to approach and condense, and achieve oil-water separation.

[0019] Compared with the prior art, the present invention has the following advantages and beneficial effects: (1) The raw materials of 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; (2) The demulsifier for crude oil containing solid phase of the present invention has good demulsification effect. When the dosage is 100 mg / L, the oil removal rate reaches more than 98%. DETAILED DESCRIPTION

[0020] The present invention will be further described in detail below in conjunction with specific examples and with reference to data. It should be understood that these examples are only intended to illustrate the present invention and are not intended to limit the scope of the present invention in any way.

[0021] Example 1 (1) Add 1 mol of methyl anthranilate and 30.2 g of sodium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 5 min, evacuate, add 4 mol of propylene oxide, heat while stirring, raise the temperature to 180°C, stop heating, keep the temperature for 2 h, cool to 85°C, and stop stirring; (2) 10 mol of ethylene oxide was introduced into the above autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 200 rpm. At the same time, the temperature was raised to 190°C, heating was stopped, and the reaction was kept at this temperature for 2 h. The reaction was cooled to 45°C and stirring was stopped; (3) 0.9 mol of acetyl chloride was introduced into the above autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 300 rpm. The reaction was kept warm for 1 hour. The autoclave was opened and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0022] Example 2 (1) Add 1 mol of methyl anthranilate and 33.4 g of sodium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 10 min, evacuate, add 8 mol of propylene oxide, heat while stirring, raise the temperature to 190°C, stop heating, keep the temperature for 2 h, cool to 90°C, and stop stirring; (2) 50 mol of ethylene oxide was introduced into the above autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 200 rpm. At the same time, the temperature was raised to 200°C, the heating was stopped, the temperature was kept for 4 hours, the reaction was cooled to 45°C, and the stirring was stopped; (3) 1.2 mol of acetyl chloride was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 300 rpm. The reaction was kept warm for 1 hour. The autoclave was opened and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0023] Example 3 (1) Add 1 mol of methyl anthranilate and 37.8 g of sodium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 6 min, evacuate, add 10 mol of propylene oxide, heat while stirring, raise the temperature to 185°C, stop heating, keep the temperature for 2 h, cool to 86°C, and stop stirring; (2) 60 mol of ethylene oxide was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 250 rpm. At the same time, the temperature was raised to 195°C, the heating was stopped, the temperature was kept for 4 hours, the reaction was cooled to 45°C, and the stirring was stopped; (3) 0.95 mol of acetyl chloride was introduced into the above autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 250 rpm. The reaction was kept warm for 1 hour. The autoclave was opened and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed; (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0024] Example 4 (1) Add 1 mol of methyl anthranilate and 35.2 g of sodium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 7 min, evacuate, add 18 mol of propylene oxide, heat while stirring, raise the temperature to 182°C, stop heating, keep the temperature for 2 h, cool to 87°C, and stop stirring; (2) 40 mol of ethylene oxide was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 220 rpm. At the same time, the temperature was raised to 192°C, heating was stopped, and the reaction was kept at this temperature for 3 hours. The reaction was cooled to 45°C and stirring was stopped; (3) 1.1 mol of acetyl chloride was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 300 rpm. The reaction was kept warm for 1 hour. The autoclave was opened and sodium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0025] Example 5 (1) Add 1 mol of methyl anthranilate and 35.7 g of potassium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 8 min, evacuate, add 26 mol of propylene oxide, heat while stirring, raise the temperature to 185°C, stop heating, keep the temperature for 3 h, cool to 88°C, and stop stirring; (2) 20 mol of ethylene oxide was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 300 rpm. At the same time, the temperature was raised to 197°C, heating was stopped, and the reaction was kept at this temperature for 3 hours. The reaction was cooled to 45°C and stirring was stopped; (3) 1.05 mol of acetyl chloride was introduced into the above autoclave at a rate of 2 ml / min. After the introduction, stirring was started at a rate of 300 rpm. The reaction was kept warm for 2 h. The autoclave was opened and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0026] Example 6 (1) Add 1 mol of methyl anthranilate and 38.9 g of potassium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 5 min, evacuate, add 30 mol of propylene oxide, heat while stirring, raise the temperature to 187°C, stop heating, keep the temperature for 3 h, cool to 89°C, and stop stirring; (2) 70 mol of ethylene oxide was introduced into the autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 300 rpm. At the same time, the temperature was raised to 198°C, heating was stopped, and the reaction was kept at this temperature for 5 hours. The reaction was cooled to 45°C and stirring was stopped. (3) 1 mol of acetyl chloride was introduced into the above autoclave at a rate of 3 ml / min. After the introduction, stirring was started at a rate of 250 rpm. The reaction was kept warm for 2 h. The autoclave was opened and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0027] Example 7 (1) Add 1 mol of methyl anthranilate and 41.4 g of potassium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 9 minutes, evacuate, add 35 mol of propylene oxide, heat while stirring, raise the temperature to 183°C, stop heating, keep the temperature for 4 hours, cool to 85°C, and stop stirring; (2) 80 mol of ethylene oxide was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 280 rpm. At the same time, the temperature was raised to 195°C, heating was stopped, and the reaction was kept at this temperature for 6 hours. The reaction was cooled to 45°C and stirring was stopped; (3) 1 mol of acetyl chloride was introduced into the above autoclave at a rate of 3 ml / min. After the introduction was completed, stirring was started at a rate of 220 rpm. The reaction was kept warm for 2 h. The autoclave was opened and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0028] Example 8 (1) Add 1 mol of methyl anthranilate and 45.3 g of potassium hydroxide to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 10 min, evacuate, add 40 mol of propylene oxide, heat while stirring, raise the temperature to 188°C, stop heating, keep the temperature for 4 h, cool to 90°C, and stop stirring; (2) 100 mol of ethylene oxide was introduced into the above autoclave at a rate of 2 ml / min. After the introduction was completed, stirring was started at a rate of 230 rpm. At the same time, the temperature was raised to 196°C, heating was stopped, and the reaction was kept at this temperature for 6 hours. The reaction was cooled to 45°C and stirring was stopped; (3) 1.05 mol of acetyl chloride was introduced into the above autoclave at a rate of 3 ml / min. After the introduction, stirring was started at a rate of 220 rpm. The reaction was kept warm for 2 h. The autoclave was opened and potassium hydroxide was slowly added to maintain the pH at 7-8 until the pH no longer changed. (4) The mixture in the reactor is dehydrated under reduced pressure to obtain a demulsifier product.

[0029] Test Example 1: Indoor Evaluation of Demulsifier The emulsion at the oil-water separation interface of a joint station of Shengli Oilfield was taken, with an oil content of 9500 mg / L. The performance of the demulsifier of the present invention (Examples 1-8) was evaluated at 60°C with reference to SY / T 5797-1993 "Method for evaluating the performance of demulsifiers for oil-in-water emulsions". The evaluation results are shown in Table 1.

[0030] Before use, the demulsifier was diluted with distilled water to a concentration of 1wt%, and a comparative experiment was performed using demulsifier PR-23 (polyoxyethylene polyoxypropylene propylene glycol monoether).

[0031] Table 1 Demulsifier performance test results From Table 1 we can see that: (1) When the demulsifier of the present invention (Examples 1-8) was used at a concentration of 50 mg / L, the oil removal rate reached more than 96%, with the highest reaching 99.1%, while the comparative demulsifier PR-23 had an emulsified layer; (2) When the demulsifier of the present invention (Examples 1-8) is used at a concentration of 100 mg / L, the oil removal rate reaches over 98%, with the highest reaching 99.5%. The oil removal rate of the comparative demulsifier PR-23 is 93%, which is significantly lower than that of the present invention.

[0032] Application Example 1: Demulsifier Field Application The No. 7 oil storage tank of a joint station in Shengli Oilfield separates the thermal recovery heavy oil. The oil-water interface produces about 50m3 of oil-water emulsion every day. 3 The oil content is 12000 mg / L. The demulsifier of Example 7 of the present invention is used for demulsification treatment at a concentration of 100 mg / L. After the treatment, the oil content of the oil-water emulsified liquid is reduced to 90 mg / L, and the oil removal rate reaches 99.2%, which meets the process requirements.

[0033] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for preparing a solid phase crude oil demulsifier, characterized in that: The specific steps of the preparation method are as follows: (1) Add methyl anthranilate and a catalyst to a high-pressure reactor, purge the pipeline and reactor with nitrogen for 5-10 minutes, evacuate, add propylene oxide, heat while stirring, raise the temperature to 180-190°C, stop heating, keep the temperature for reaction, cool to 85-90°C, and stop stirring; (2) Add ethylene oxide to the autoclave at a rate of 2-3 ml / min. After the addition is complete, start stirring and raise the temperature to 190-200°C. Stop heating, keep the temperature for reaction, cool to 45°C, and stop stirring. (3) Add acetyl chloride to the autoclave at a rate of 2-3 ml / min. After the addition is complete, start stirring, keep the reaction warm, open the autoclave, slowly add the catalyst, maintain the pH at 7-8, until the pH no longer changes; (4) dehydrating the mixture in the reactor under reduced pressure to obtain a demulsifier product; Based on 1 mole of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride are 4-40, 10-100 and 0.9-1.2 mole parts respectively; The demulsifier molecular formula is as follows: in: m, n are natural numbers from 2 to 20; x and y are natural numbers between 5 and 100.

2. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: Based on 1 mole of methyl anthranilate, the amounts of propylene oxide, ethylene oxide and acetyl chloride used are 10-40, 40-100 and 1-1.1 mole parts respectively.

3. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: 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.

4. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: The heat preservation reaction time in step (1) is 2-4 hours.

5. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: The insulation reaction time in step (2) is 2-6 hours.

6. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: The insulation reaction time in step (3) is 1-2 hours.

7. The method for preparing a solid phase crude oil demulsifier according to claim 1, characterized in that: The catalyst in step (3) is sodium hydroxide or potassium hydroxide particles.

8. A solid phase crude oil demulsifier, characterized in that: The molecular formula of the solid phase crude oil demulsifier is as follows: in: m, n are natural numbers from 2 to 20; x and y are natural numbers between 5 and 100.

9. A solid phase crude oil demulsifier as claimed in claim 8, characterized in that: The molecular formula of the solid phase crude oil demulsifier is as follows: in: m, n are natural numbers between 5 and 10; x and y are natural numbers between 20 and 50.

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