WO2020258358A1

WO2020258358A1 - Three-dimensional crude oil demulsifier, preparation method therefor, and application thereof

Info

Publication number: WO2020258358A1
Application number: PCT/CN2019/094657
Authority: WO
Inventors: 崔学章; 崔仕章; 王黎明; 于长禄; 谷之辉; 徐丽君; 吴丽丽; 刘骁
Original assignee: 德仕能源科技集团股份有限公司; 山东德仕化工有限公司
Priority date: 2019-06-28
Filing date: 2019-07-04
Publication date: 2020-12-30
Also published as: CN110343545B; CN110343545A

Abstract

A three-dimensional crude oil demulsifier, a preparation method therefor, and an application thereof. The demulsifier is a polymer formed by connecting two structural units, and is prepared by the following method: (1) preparation of initiator: after mixing polyethylene polyamine, phenol, and formaldehyde, sequentially performing heating, refluxing, dehydration and solvent removal, and cooling on the mixture, so as to obtain an initiator; (2) preparation of intermediate: adding an alkali powder to the initiator, sequentially adding propylene oxide and ethylene oxide under vacuum conditions and reacting the same at 120°C to 140°C for 4-6 h, and then cooling to obtain an intermediate; and (3) preparation of demulsifier: adding a bisphenol A epoxy resin to the intermediate and reacting at 75°C to 90°C for 4-6 h, and then cooling to obtain a demulsifier. The demulsifier is used for the dehydration of crude oil, and can enhance the penetration and diffusion of demulsifier molecules in heavy oil, shorten the diffusion time of the demulsifier, and improve the demulsification performance of the demulsifier product.

Description

Body type crude oil demulsifier and preparation method and application thereof

Technical field

This application relates to the field of petrochemical technology, in particular to a bulk crude oil demulsifier and a preparation method thereof.

Background technique

In recent years, with the continuous development of oilfields, the oilfields are gradually aging, the water content in the extracted crude oil is getting higher and higher, and some crude oil has even changed to heavy. In order to increase the oil recovery rate, each oil area adopts different enhanced oil recovery technologies according to the formation characteristics, such as alkaline flooding, acid fracturing operations, foam flooding, polymer flooding, steam flooding, surfactant flooding, surfactant-polymer two The application of these technologies, such as yuan flooding and alkali-surfactant-polymer ternary combination flooding, provides effective measures for stabilizing and increasing oilfield production, and has achieved huge economic benefits. However, due to the implementation of these measures, the injection of a large number of chemical substances into the oil layer not only significantly increased the salinity of the formation water quality, but also caused major changes in the nature of crude oil in many oil regions. The degree of emulsification of the produced crude oil is further enhanced, and high alkaline crude oil, high acid value crude oil, heavy oil, extra-heavy oil, high freezing point crude oil, tertiary oil recovery crude oil, high salinity water crude oil, etc. appeared, and even produced The crude oil and water formed oil-in-water (O/W) and multiple (O/W/O, W/O/W) emulsions, resulting in differences in the state of crude oil, and the oilfield currently has high demulsification and dehydration temperatures. Large amount, unsatisfactory discharged sewage and other problems, cause huge waste of energy.

Demulsifier is a surface active agent that partially replaces the crude oil emulsion stabilizing film, thereby destroying the stability of the crude oil emulsion and separating the crude oil and water in the crude oil emulsion. At present, the most effective demulsifiers used in my country’s oilfields are demulsifiers with polyether as the main body, especially polyether demulsifiers with phenolic resin as the initiator. They have strong surface activity, strong adaptability, and better lubrication. Wet performance, sufficient flocculation capacity and high coalescence efficiency.

However, the polyether demulsifiers currently studied often have shortcomings such as small molecular weight, difficult to demulsify heavy oil, uneven diffusion, slow demulsification speed, and low dehydration rate. For example, the demulsifiers provided by CN103146418A and CN102746470A are end-blocked and modified by unsaturated acids such as acrylic acid and have a small molecular weight; CN1537924A uses water-soluble crosslinking agents to synthesize demulsifiers, and the products made are not oil-soluble, and the demulsification effect is not as good as oil-soluble ones. The emulsion is good; CN102676209A uses dicarboxylic acid to cross-link and modify the demulsifier intermediate molecules, but its penetration and diffusion properties in heavy oil are average, which reduces the demulsification efficiency.

Summary of the invention

In order to solve the above problems, the present invention aims to provide a crude oil demulsifier with higher molecular weight, fast dehydration speed, higher absolute dehydration rate, and capable of effectively processing heavy oil emulsions and a preparation method thereof.

In one aspect, the present invention provides a bulk crude oil demulsifier, which has a polymer composed of structural units represented by formula (I) and formula (II) connected by (I)-(II)-(I):

among them,

R': R removes active hydrogen; n _{1 is} 1-30, n _{2 is} 1-5; the molecular weight of the polymer is 8000-10000.

Preferably, the active hydrogen on R includes hydrogen on the phenyl hydroxyl group and amino hydrogen on the polyvinyl polyamine structure in the formula.

Further, the polymer has a density of 1.00-1.02 g/cm ³ , a pH value of 7-9, and a flash point ≥50°C; the appearance is a dark yellow viscous uniform liquid with a solid content ≥95%.

Further, the viscosity of the polymer is less than 300 mPa.s, and the freezing point is less than or equal to -35°C.

Further, the absolute dehydration rate of the polymer is ≥93%.

In the polymer represented by the above formula, the structure with subscripts x and y is derived from the raw material polyethylene polyamine, and the structure with subscript n is derived from bisphenol A epoxy resin.

The crude oil demulsifier provided in this application utilizes the characteristics of the two epoxy groups in the bisphenol A epoxy resin to effectively cross-link the two demulsifier intermediate molecules together to obtain the final product of the body structure and make the final product The molecular weight of the demulsifier product increases, and it also has more benzene ring structures. The benzene ring structure can enhance the penetration and diffusion of the demulsifier molecules in the heavy oil, and can achieve a uniform distribution in the heavy oil in a short time. To shorten the demulsifier diffusion time, make the demulsifier molecules act as soon as possible, improve the demulsification efficiency, shorten the demulsification time, and thus improve the demulsification performance of the demulsifier product.

On the other hand, the present invention also provides a method for preparing the above-mentioned bulk crude oil demulsifier, including:

(1) Preparation of starter: After mixing polyethylene polyamine, phenol and formaldehyde, heating, refluxing, dehydration and desolvation are carried out in sequence, and the temperature is lowered to obtain the starter;

(2) Preparation of intermediates: adding alkali powder to the starting agent, adding propylene oxide and ethylene oxide sequentially under vacuum conditions, reacting at 120°C-140°C for 4-6 hours, and cooling to obtain intermediates;

(3) Preparation of demulsifier: Add bisphenol A epoxy resin to the intermediate, react at 75°C-90°C for 4-6 hours, and cool down to obtain the demulsifier.

Further, the bisphenol A epoxy resin is selected from one or more of epoxy resin 828 and epoxy resin E-51, preferably epoxy resin 828.

Further, the added mass ratio of the bisphenol A epoxy resin and the intermediate is 3 to 5:50.

Further, in the step (1), the reaction molar ratio of phenol, formaldehyde and polyethylene polyamine is 1:3:3.

Further, the formaldehyde in the step (1) is 37% formaldehyde solution or paraformaldehyde.

Further, the addition mass ratio of the initiator, propylene oxide, and ethylene oxide in the step (2) is 1:(15～35):(4～6), preferably 1:(20～30): (4.5-5.5), more preferably 1:29:5.

Further, the solvent in the step (1) and/or step (2) is xylene. Preferably, in step (1), the polyvinyl polyamine and molten phenol are dissolved in xylene, and then formaldehyde is added dropwise to it; in step (2), the intermediate and bisphenol A epoxy resin are separately dissolved in two Remix in toluene, where the mass ratio of bisphenol A epoxy resin to xylene is 1:4.

Further, in the above method, an electric heating reactor and/or polymerization reactor is used.

In a preferred embodiment, the above preparation method specifically includes the following steps:

(1) Add xylene, polyvinyl polyamine, and molten phenol to the electric heating reactor in sequence, stir well at 50-60℃, then add 37% formaldehyde solution dropwise at constant temperature, and react for 2h; and then at 120℃- Reaction at 130°C for 2h, reflux dehydration at 150°C-160°C for 6h, solvent removal at 220°C-240°C for 4h, cooling to 100°C-110°C to obtain the initiator;

(2) Add alkali powder to the starting agent, vacuum dehydration at 140℃ for 1h, pass in propylene oxide and react for 2h. The reaction conditions are temperature 130℃, pressure -0.1Mpa～-0.05Mpa; pass in ethylene oxide After reacting for 2h, the reaction conditions are temperature 125°C, pressure -0.1Mpa～-0.05Mpa; after the reaction is completed, the temperature is reduced to 65°C-70°C to obtain the intermediate;

(3) Stir the intermediate and xylene at 80°C evenly, then dissolve the bisphenol A epoxy resin in xylene and add it dropwise to the xylene solution of the intermediate for 1.5-2h. React at ℃ for 3h, then cool to 65-70℃ to obtain demulsifier.

On the other hand, the present invention also provides a crude oil demulsifier prepared by the above method.

The synthetic route for preparing crude oil demulsifier by the above method is as follows:

Synthesis of body resin initiator R:

Synthesis of Body Demulsifier Intermediate Y:

among them:

R'is: R removes the active hydrogen on the phenyl hydroxyl group.

Among them, let the intermediate be Y:

Synthesis of body crude oil demulsifier:

On the other hand, the present invention also provides the above crude oil demulsifier and/or the application of the crude oil demulsifier prepared by the above method to increase the dehydration rate of crude oil. Preferably, the water content of the crude oil is less than or equal to 30%.

The crude oil demulsifier provided by the present invention has fast dehydration speed, clear water quality and uniform oil-water interface, exhibits significant demulsification and dehydration performance, and has a dehydration and demulsification effect higher than that of existing demulsifiers. Experiments show that the crude oil demulsifier provided by the present invention treats crude oil with a water content of 30% at 70°C for 90 minutes, the absolute dehydration rate at a concentration of 50 ppm is as high as 95.8%, and the absolute dehydration rate at a concentration of 100 ppm is 100%.

Through this application, the following beneficial effects can be brought about:

1. The crude oil demulsifier provided by the present invention utilizes the characteristics of the two epoxy groups in the bisphenol A epoxy resin to effectively cross-link the two demulsifier intermediate molecules together to obtain the final product of the body structure. The molecular weight of the final demulsifier product is increased, thereby improving the demulsification performance of the demulsifier product. Experiments show that the absolute dehydration rate of the crude oil demulsifier provided by the present invention is ≥93%;

2. The crude oil demulsifier provided by the present invention also has more benzene ring structures, and the benzene ring structure can enhance the penetration and diffusion of the demulsifier molecules in the heavy oil, and can achieve a uniform distribution in the heavy oil in a short time. In this way, the diffusion time of the demulsifier is shortened, the molecules of the demulsifier can act as soon as possible, the efficiency of demulsification is improved, and the demulsification time is shortened;

3. The crude oil demulsifier provided by the present invention can be water-soluble or oil-soluble, and can be adjusted for different site conditions, so that it can exert its best performance on site and stabilize the site;

The preparation method of the bulk crude oil demulsifier provided by the invention is simple, and the raw materials are easily available, so that the bulk crude oil demulsifier is easy to industrially produce.

Detailed ways

In order to explain the overall concept of the application more clearly, a detailed description will be given below by way of examples. In the following description, a lot of specific details are given in order to provide a more thorough understanding of this application. However, it is obvious to those skilled in the art that this application can be implemented without one or more of these details. In other examples, in order to avoid confusion with this application, some technical features known in the art are not described.

Unless otherwise specified, the reagents in the following examples are all commercially available. Among them, polyethylene polyamine is provided by Shanghai Aladdin Biochemical Technology Co., Ltd. CAS: 29320-38-5; xylene, phenol and formaldehyde are all purchased from Yantai Far East Fine Chemical Co., Ltd.; epoxy resin 828 is provided by Hexion HEXION Provided by the company; both ethylene oxide and propylene oxide are taken from industrial samples. The purity of the above reagents is analytical grade.

Example 1

Example 1 provides a method for preparing a bulk crude oil demulsifier, including the following steps:

(1) Preparation of initiator R

Add 300kg of xylene, 700kg of polyvinyl polyamine, and 90kg of molten phenol to a dry and clean electric heating reactor. The temperature is raised to 50℃～60℃ and stirred until the state is uniform; then under constant temperature, add to the dripping tank Add 240kg of formaldehyde solution with 37% content and control the dripping time for 0.5h～1h. After the dripping is completed, keep the reaction for 2h; then increase the temperature to 120℃～130℃ and continue the constant temperature reaction for 2h, and continue to increase the temperature to 150℃～160℃, Reflux dehydration for 6 hours to dry out, continue to heat up to 220 ℃ ~ 240 ℃, dehydration and solvent removal for 4 hours until there is no liquid out, and cool down to 100 ℃ ~ 110 ℃ to obtain body resin initiator R, transfer to the kettle for later use.

(2) Preparation of intermediate Y-OH

Add 100kg of bulk resin initiator R100kg and 17kg of potassium hydroxide powder to a dry and clean polymerization kettle, stir and raise the temperature to 140℃ to start vacuum dehydration for 1h, then cool to 130℃, pass 2900kg of propylene oxide, and control the temperature during the reaction 130℃±5℃, control the reaction pressure ≤0.5Mpa, after the feeding is completed, keep the reaction at 130℃ for 2h and the pressure drops to between -0.1Mpa～-0.05Mpa; continue to pass in 500kg of ethylene oxide and start After the reaction, slowly lower the temperature. During the reaction, control the temperature to 125°C±5°C, and control the reaction pressure to ≤0.5Mpa. After the feeding is completed, keep the reaction at 125°C for 2h and the pressure drops to between -0.1Mpa～-0.05Mpa , The reaction is complete. The temperature in the reactor is lowered to 65°C～70°C, and the material is discharged to obtain the body type demulsifier intermediate Y-OH.

(3) Preparation of body type demulsifier

Add 500kg of bulk demulsifier intermediate Y-OH and 300kg of xylene to a dry and clean reaction kettle, heat up to 80℃ and stir until the state is uniform; prepare epoxy resin 828 solution according to the ratio of epoxy resin 828: xylene=50kg: 200kg , And then pumped into the dripping tank, slowly drip the epoxy resin 828 solution under the condition of 80℃±2℃, pay attention to control the temperature during the dripping process, control the dripping time 1.5h～2h, and raise the temperature to 85 after the dripping is completed ℃, keep the reaction temperature for 3h, then lower the temperature to 65℃～70℃, release the material to get the body type demulsifier.

Example 2

Example 2 provides a bulk crude oil demulsifier prepared in Example 1. The bulk crude oil demulsifier is a polymer having the following structural formula:

In the formula, the structural formula of Y is as follows:

In the formula, R'is the R in the following formula to remove active hydrogen:

In the formula: n _{1 is} 1 to 30, n _{2 is} 1 to 5; wherein, the active hydrogen on R includes hydrogen on the phenyl hydroxyl group in the formula and amino hydrogen on the polyvinyl polyamine structure.

The obtained polymer has a molecular weight of 8000-10000, a density of 1.00-1.02g/cm ³ , a pH value of 7-9, and a flash point ≥50℃; its appearance is a dark yellow viscous uniform liquid, no mechanical impurities, and solid content ≥95%; viscosity <300mPa.s, freezing point≤-35℃, absolute dehydration rate≥93%.

Example 3 Crude oil demulsification experiment

The above-mentioned crude oil demulsifier is denoted by the code name DST, and the demulsification performance test is performed on it. Six kinds of agents with good indoor evaluation effects and on-site agents are selected, and the experiments are carried out at the same temperature and different dosages. Among them, the crude oil sample comes from Le'an Joint Station, the water content of the oil sample is 30%, the dehydration temperature is 75°C, and the test results obtained are Table 1:

Table 1 Comparison of the demulsification effect of the bulk crude oil demulsifier provided by the present invention and other demulsifiers at different dosages

Note: The agent used on site is LALP.

According to Table 1, it can be seen that the bulk crude oil demulsifier provided by the present invention has a fast dehydration speed, has an even oil-water interface, and has clear water quality, and has significant demulsification dehydration performance. At the same time, the dehydration rate of DST demulsifier reaches 95.8% at a concentration of 50ppm, which is much higher than the on-site dehydration rate of 79.2% at the same concentration, and the effect is the same as that under the condition of 100ppm. The dehydration rate under the condition of the drug concentration of 100ppm is as high as 100%, and the dehydration and demulsification effect of DST demulsifier is higher than other demulsifiers under the same concentration of drug dosage.

Based on the above, it can be seen that the crude oil demulsifier provided by the present invention has a body structure and a larger molecular weight, and exhibits significant demulsification performance. At the same time, it has good penetration and diffusibility in heavy oil, and can be used in heavy oil in a short time. Achieve uniform distribution, shorten the diffusion time of the demulsifier, and can be adjusted according to different site conditions, so that it can exert the best performance on the site, and the preparation method is simple, the raw materials are easy to obtain, and the industrial production is easy.

The above descriptions are only examples of this application and are not used to limit this application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included in the scope of the claims of this application.

Claims

A bulk crude oil demulsifier, characterized in that it has a polymer composed of structural units represented by formula (I) and formula (II) connected by (I)-(II)-(I):

among them,

R’: R removes active hydrogen;

n 1 is 1-30, n 2 is 1-5; the molecular weight of the polymer is 8000-10000.
The crude oil demulsifier according to claim 1, wherein the polymer has a density of 1.00-1.02 g/cm 3 , a pH of 7-9, and a flash point ≥50°C; the appearance properties of the polymer It is a dark yellow viscous uniform liquid with a solid content of ≥95%.
A method for preparing a bulk crude oil demulsifier according to claim 1 or 2, characterized in that it comprises:

(1) Preparation of starter: After mixing polyethylene polyamine, phenol and formaldehyde, heating, refluxing, dehydration and solvent removal are carried out in sequence, and the temperature is lowered to obtain the starter;

(2) Preparation of intermediates: adding alkali powder to the starting agent, adding propylene oxide and ethylene oxide sequentially under vacuum conditions, reacting at 120°C-140°C for 4-6 hours, and cooling to obtain intermediates;

(3) Preparation of demulsifier: add bisphenol A epoxy resin to the intermediate, react at 75°C-90°C for 4-6 hours, and cool down to obtain the demulsifier.
The method according to claim 3, wherein the bisphenol A epoxy resin is selected from one or more of epoxy resin 828 and epoxy resin E-51.
The method according to claim 3, wherein the added mass ratio of the bisphenol A epoxy resin to the intermediate is 3 to 5:50.
The method according to claim 3, wherein the reaction molar ratio of phenol, formaldehyde and polyvinyl polyamine in the step (1) is 1:3:3.
The method according to claim 3, wherein the formaldehyde in the step (1) is 37% formaldehyde solution or paraformaldehyde.
The method according to claim 3, characterized in that in the step (2), the addition mass ratio of the initiator, propylene oxide, and ethylene oxide is 1:(15～35):(4～6) .
The method according to any one of claims 3-8, wherein xylene is used as a solvent in the step (1) and/or step (2).
The crude oil demulsifier according to any one of claims 1-2, and/or the crude oil demulsifier prepared by the method according to any one of claims 3-9 is used to increase the dehydration rate of crude oil. Preferably, the crude oil contains The amount of water is less than or equal to 30%.