CN104277816A - Sulfonate type amphoteric high-molecular surfactant and synthesis method thereof - Google Patents

Abstract

The invention discloses a sulfonate type amphoteric high-molecular surfactant and a synthesis method thereof. The sulfonate type amphoteric high-molecular surfactant is prepared by the following steps: (1) mixing and stirring 1mol of long-chain alkyl dimethyl allyl ammonium bromide with 1.2-20 mol of acrylonitrile, controlling the temperature to 0DEG C, dropwise adding 1.2-20mol of fuming sulfuric acid, stirring for 0.5-2h, warming to 20-50DEG C, and reacting for 12-48h to obtain an amphoteric sulfonate type surfactant; and (2) dissolving the amphoteric sulfonate type surfactant and 2-acrylamide-2-methyl sulfonate into water according to the mole ratio of (0.1-3):(7-9.9), regulating the pH value to 7, adding an initiator, warming to 30-60DEG C, and reacting for 3-10h. The high-molecular surfactant not only can tackify in a certain mineralization range of a saline solution, but also has excellent surface activity and emulsion performance, and the method is mild in conditions, the yield is high and the purification and separation are easy.

Description

A class of sulfonate type amphoteric macromolecule surfactant and its synthesis method

technical field

The invention relates to a class of sulfonate type amphoteric macromolecule surfactants and a synthesis method thereof.

Background technique

With the rapid increase of people's demand for energy and the depletion of oil and gas resources worldwide, people are focusing more and more attention on how to effectively exploit the crude oil remaining underground in old oilfield blocks, and have developed many enhanced oil recovery technologies. New methods of EOR, such as thermal recovery, gas flooding, miscible flooding, microbial flooding, chemical flooding, etc. Among them, chemical flooding has been widely popularized and applied due to its low cost, wide application range, and effective enhancement of oil recovery, and breakthroughs have been made.

Chemical flooding EOR measures are mainly divided into three types: polymer flooding, polymer-surfactant flooding (SP), and alkali-polymer-surfactant ASP flooding (ASP). But all three approaches have some problems. In polymer flooding, the oil displacement system mainly increases the viscosity of the working fluid by adding water-soluble polymers, thereby increasing the mobility ratio of the injected fluid to the formation crude oil and improving the sweep coefficient of the oil displacement system. However, such working fluids usually have low interfacial activity, cannot effectively change the wettability of rock surfaces, and basically have no compatibilization and emulsification capabilities for crude oil, so their applications are limited. SP flooding and ASP flooding can effectively improve the interfacial activity of the working fluid, significantly reduce the oil-water interfacial tension, and effectively emulsify and toughen crude oil. However, their significant disadvantages are that the system viscosity is low due to the interaction between the surfactant and the polymer, and The cost of working fluid is higher. In addition, due to the great difference in the adsorption characteristics and diffusion capabilities of surfactants and water-soluble polymers, during the migration of porous media in the formation, the working fluids of SP flooding and ASP flooding are prone to chromatographic separation effects, which greatly weakens the ability of the working fluids. , or even lead to its failure. In addition, the introduction of alkali in ASP flooding will cause serious damage to pipelines and formations. In view of the above problems, it is urgent to develop new oil displacement materials to make up for the defects of the current oil displacement system.

The present invention synthesizes a class of polymer surfactants, which not only have the characteristics of traditional water-soluble polymers, but also can increase viscosity in aqueous solutions, and have good surface activity, which can effectively reduce oil-water interfacial tension and emulsify crude oil and hydrocarbons. Due to its unique performance, as a new type of oil displacement agent, it has important application value for enhanced oil recovery.

Contents of the invention

The purpose of the present invention is to provide a class of sulfonate-type amphoteric polymer surfactants, which are mainly used in oil exploration and drilling and completion industries. They not only have the characteristics of traditional water-soluble polymers, but also can be used in certain salinity ranges. It can increase viscosity in brine solution, and has good surface activity and emulsifying properties, which can effectively emulsify crude oil and hydrocarbons. Due to its unique properties, it has important application value for enhancing oil recovery.

Another object of the present invention is to provide a synthesis method of the above-mentioned sulfonate-type amphoteric polymer surfactant. The method is reliable in principle, easy to operate, mild in conditions, high in yield, easy to purify and separate, and has broad market prospects.

In order to achieve the above technical objectives, the present invention provides the following technical solutions.

A class of sulfonate-type amphoteric polymer surfactants, with two structural units of 2-acrylamide-2-methylpropanesulfonic acid (AMPS) and amphoteric sulfonate-type surfactants (AMC _n DMAPS), its structural formula as follows:

Wherein x and y are the number of structural units, x is 70-99%, and y is 1-30%.

A synthetic method of a class of sulfonate type amphoteric macromolecular surfactants, comprising the following steps in turn:

(1) Add 1 mol of long-chain alkyl dimethyl allyl ammonium bromide (C _n DMAAB, n=12-22), 1.2-20 mol of acrylonitrile into a three-necked flask for stirring, and cool the reaction system with an ice-salt bath Control the temperature to 0°C, add 1.2-20mol oleum dropwise through a constant-pressure dropping funnel, stir for 0.5-2h, then raise the temperature to 20-50°C, and react at constant temperature for 12-48h, then filter to remove excess acrylonitrile to obtain Yellow crystals, recrystallized with acetone to obtain colorless crystals, that is, amphoteric sulfonate surfactants (AMC _n DMAPS, n=12-22);

(2) Dissolving amphoteric sulfonate surfactant (AMC _n DMAPS, n=12～22) and 2-acrylamide-2-methylpropanesulfonic acid (AMPS) in water, amphoteric sulfonate surfactant The molar ratio of agent and 2-acrylamide-2-methylpropanesulfonic acid is 0.1～3:7～9.9, the pH value is adjusted to about 7 with sodium bicarbonate solution, and the total monomer concentration is 10～30% by mass. Into nitrogen for 30 minutes to remove oxygen, then add the initiator azobisisobutylimidazoline hydrochloride (AIBI), the amount of the initiator added is 0.05-1.5% of the total mass of the monomer, the temperature of the system is raised to 30-60 °C, and the reaction 3 After ~10h, use ethanol and acetone to repeatedly precipitate and wash, dry the product in a vacuum oven at 40°C for 48h, pulverize and granulate, and obtain the sulfonate-type amphoteric polymer surfactant AMPS/AMC _n DMAPS (n= 12~22).

In the present invention, acrylonitrile is firstly used as a solvent, and long-chain alkyl dimethyl allyl ammonium bromide is reacted with oleum and acrylonitrile under ice-salt bath conditions to obtain amphoteric sulfonate-type surfactant mono body (AMC _n DMAPS, n=12-22). Then the free-radical aqueous polymerization method was used to obtain the no-regression micro-block copolymer. Its reaction formula is as follows:

Compared with the prior art, the present invention has the following beneficial effects:

1. The synthetic sulfonate type amphoteric macromolecule surfactant of the present invention, its synthetic raw material is simple and easy to get, and its synthetic method is convenient and concise.

2. This type of polymer surfactant has good surface activity, can effectively reduce the interfacial tension of oil and water, has good emulsifying performance, can effectively emulsify organic solvents and crude oil, and improve oil recovery.

Description of drawings

Figure 1 is the ¹ HNMR spectrum of sulfonate-type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Figure 2 is the relationship curve between the viscosity of the sulfonate type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS solution and the concentration of NaCl

Figure 3 is the influence curve of the sulfonate-type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS on the oil-water interfacial tension

Detailed ways

Further illustrate the present invention according to accompanying drawing and embodiment below.

1. Preparation of sulfonate type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Example 1

Add 209.3 g of octadecyl dimethyl allyl ammonium bromide and 265.3 g of acrylonitrile into a three-necked flask for stirring, use an ice-salt bath to control the temperature of the reaction system to 0°C, and then drop through a constant pressure dropping funnel. Add 1.2-20mol oleum, stir for 0.5h, then raise the temperature to 40°C, and react at constant temperature for 36h. After the reaction, the reaction system was cooled, and excess acrylonitrile was removed by filtration to obtain the crude product as pale yellow crystals. The crude product was recrystallized with acetone to obtain colorless crystals, namely amphoteric sulfonate surfactant monomer (AMC ₁₈ DMAPS).

Dissolve 7.40g of AMC ₁₈ DMAPS and 51.8g of AMPS in water, and use sodium bicarbonate solution to adjust the pH value to about 7, the total monomer concentration is 20% by mass, pass nitrogen gas for 30min to remove oxygen, and then add 0.5g of initiator azobis Isobutimidazoline hydrochloride, the temperature of the system is raised to 50°C, and the reaction is completed after 5 hours of reaction. After repeated precipitation and washing with ethanol and acetone, it is dried in a vacuum oven at 40°C for 48 hours. After crushing and granulating, the obtained white powder It is sulfonate type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS.

2. Structural characterization of sulfonate-type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Fig. 1 is the ¹ HNMR spectrogram of AMPS/AMC ₁₈ DMAPS prepared in embodiment 1, after comparing and calculating the integral area ratio of the characteristic H of polymer AMPS/AMC ₁₈ DMAPS, it is found that in the polymer AMPS and AMC ₁₈ DMAPS The ratio is basically consistent with the input ratio of the monomer, indicating that the polymer AMPS/AMC ₁₈ DMAPS was successfully synthesized. Between 5 and 7 ppm, there is no characteristic shift value of olefinic hydrogen, which indicates that there is no residual monomer in the polymer.

3. Salt resistance test of sulfonate type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Fig. 2 is the influence curve of NaCl concentration on the viscosity of AMPS/AMC ₁₈ DMAPS. It can be seen from the figure that the viscosity of polymer AMPS/AMC ₁₈ DMAPS solution increases with the increase of brine concentration. When the NaCl concentration is 2000mg/L, the solution viscosity reaches the maximum, and the system viscosity is 161.2mPa.s. Continuing to increase the NaCl concentration, the viscosity of the polymer solution begins to decrease. When the NaCl concentration is 10000mg/L, the system viscosity is 10.43mPa.s. Tests show that the polymer AMPS/AMC ₁₈ DMAPS has good salt resistance.

4. Oil-water interfacial tension test of sulfonate-type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Fig. 3 is the influence curve of AMPS/AMC ₁₈ DMAPS prepared in Example 1 on oil-water interfacial tension. It can be seen from the figure that the oil-water interfacial tension decreases with the increase of the polymer AMPS/AMC ₁₈ DMAPS solution concentration. When the polymer solution concentration is 1000mg/L, the oil-water interfacial tension is 5.73mN m ^-1 . Continuing to increase the polymer AMPS/AMC ₁₈ DMAPS solution concentration, the oil-water interfacial tension changes little. Tests show that the polymer AMPS/AMC ₁₈ DMAPS solution has good surface activity and can effectively reduce the oil-water interfacial tension.

5. Emulsification effect test of sulfonate type amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS

Add the prepared polymer solution with a concentration of 5000mg/L to crude oil and kerosene according to the oil-water ratio of 1:1. After stirring evenly, pour it into a graduated test tube and let it stand for 12 hours. Emulsification rate, see Table 1.

Table 1 emulsification performance test results

It can be seen from Table 1 that the emulsification rate of sulfonate amphoteric polymer surfactant AMPS/AMC ₁₈ DMAPS is 100%, while that of HPAM is only 27%. Compared with HPAM solution, the sample after adding polymer AMPS/AMC ₁₈ DMAPS solution has obvious emulsification effect, and has good dispersion and emulsification performance for kerosene and crude oil. In addition, the emulsion still has no delamination phenomenon after standing for a week, and the emulsion stability has increased significantly, which indicates that the formed emulsion has high stability. However, no emulsification phenomenon occurred in the solution without adding the polymer of the present invention, and stratification occurred soon after the stirring was stopped.

Claims (2)

1. a class sulfonate amphoteric polymeric surface active agent, have 2-acrylamide-2-methyl propane sulfonic and both sexes sulfonate surfactant two kinds of structural units, its structural formula is as follows:

R＝C ₁₂～C ₂₂alky?chain

Wherein x, y are structural unit number, and x is 70 ~ 99%, y is 1 ~ 30%.

2. the synthetic method of sulfonate amphoteric polymeric surface active agent as claimed in claim 1, comprises the following steps successively:

(1) by 1mol carbon number be 12 ~ 22 long chain alkyl dimethyl allylic bromination ammonium, 1.2 ~ 20mol vinyl cyanide joins in there-necked flask and stirs, temperature of reaction system is controlled to 0 DEG C, drip 1.2 ~ 20mol oleum, stir 0.5-2h, be warming up to 20-50 DEG C, after isothermal reaction 12-48h, cross and filter excessive vinyl cyanide, obtain light yellow crystal, with acetone recrystallization, obtain both sexes sulfonate surfactant;

(2) by both sexes sulfonate surfactant and 2-acrylamide-2-methyl propane sulfonic soluble in water according to mol ratio 0.1 ~ 3:7 ~ 9.9, adjust ph is about 7, total monomer is 10 ~ 30 quality %, pass into nitrogen 30min and carry out deoxygenation, add initiator azo two isobutyl imidazoline hydrochloride again, initiator dosage is 0.05 ~ 1.5% of monomer total mass, system is warming up to 30 ~ 60 DEG C, after reaction 3 ~ 10h, with ethanol and the washing of acetone repeated precipitation, by product dry 48h in 40 DEG C of vacuum drying ovens, after pulverizing granulation, obtain sulfonate amphoteric polymeric surface active agent.