CN107456917B

CN107456917B - Preparation method of double quaternary ammonium cation Gemini surfactant and surfactant solution containing same

Info

Publication number: CN107456917B
Application number: CN201710631028.9A
Authority: CN
Inventors: 郭宏峰; 李翔; 李敬松; 常振; 张博; 刘文辉; 黄侠; 赵广渊; 铁磊磊; 林科雄; 舒福昌; 任坤峰; 吴杰
Original assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Current assignee: China Oilfield Services Ltd; China National Offshore Oil Corp CNOOC
Priority date: 2017-07-28
Filing date: 2017-07-28
Publication date: 2020-02-07
Anticipated expiration: 2037-07-28
Also published as: CN107456917A

Abstract

A preparation method of a double quaternary ammonium cation Gemini surfactant, a water injection well pressure-reducing injection-increasing surfactant solution containing the double quaternary ammonium cation Gemini surfactant and a preparation method thereof are provided, the preparation method of the double quaternary ammonium cation Gemini surfactant comprises the steps of carrying out solution polymerization reaction on dodecyl dimethylamine and dodecyl alcohol glycidyl ether in a solvent, and carrying out reflux reaction for a period of time; the water injection well pressure-reducing injection-increasing surfactant solution containing the double quaternary ammonium cation Gemini surfactant comprises 30-40 parts by mass of the double quaternary ammonium cation Gemini surfactant prepared by the method and 70-60 parts by mass of water; the method for preparing the water injection well pressure-reducing and injection-increasing surfactant solution comprises the step of stirring and mixing the double quaternary ammonium cation Gemini surfactant and water. The water injection well pressure-reducing and injection-increasing surfactant can remarkably reduce oil-liquid interfacial tension, has certain capability of changing rock wettability, and reduces water injection pressure.

Description

Preparation method of double quaternary ammonium cation Gemini surfactant and surfactant solution containing same

Technical Field

The application relates to but is not limited to the field of oilfield chemical application, in particular to but not limited to a preparation method of a double quaternary ammonium cation Gemini surfactant, a water injection well pressure-reducing injection-increasing surfactant solution containing the double quaternary ammonium cation Gemini surfactant and a preparation method of the surfactant solution.

Background

The crude oil viscosity of the heavy oil reservoir is high, and asphaltene and other polar substances in the heavy oil are adsorbed on an oil-water interface and an oil-rock interface in the development process to form a thick viscous film, so that an oil-water emulsion is stabilized, the rock wettability is changed, and the crude oil has poor liquidity. Meanwhile, residual oil, oil droplets and an oil film on the surface of the rock in the rock pore throat reduce the number of effective pore throats, the radius of the effective pore throats, the effective permeability and the later-period pollution. The surfactant system is injected into the stratum to reduce the interfacial tension and increase the dissolving capacity of crude oil, so that large oil drops in pore throats are emulsified to form small oil drops to form an oil-in-water (O/W) emulsion, the emulsion flows more easily compared with the crude oil after the crude oil is emulsified into a water phase, the emulsion is carried by the water phase to flow together by utilizing an emulsion carrying mechanism, dead oil in a near-wellbore area is cleaned, the saturation degree and the seepage resistance of residual oil are reduced, the water phase permeability is improved, and the purposes of reducing pressure and increasing injection are achieved.

Disclosure of Invention

The following is a summary of the subject matter described in detail herein. This summary is not intended to limit the scope of the claims.

The application aims to provide a method for preparing a double quaternary ammonium cation Gemini surfactant.

The method for preparing the double quaternary ammonium cation Gemini surfactant comprises the following steps: in a solvent, carrying out solution polymerization reaction on dodecyl dimethylamine and lauryl alcohol glycidyl ether, and carrying out reflux reaction for a period of time to obtain the bis-quaternary ammonium cation Gemini surfactant.

In an embodiment of the present application, the charging molar ratio of the dodecyldimethylamine to the dodecanol glycidyl ether can be 4-6: 1.

In embodiments herein, the molar ratio of dodecyldimethylamine to dodecanol glycidyl ether can be 5: 1.

In the present application, the amount of the solvent used is not critical as long as it can dissolve dodecyldimethylamine and dodecanol glycidyl ether.

In embodiments of the present application, the solution polymerization reaction is carried out under initiation of an initiator, which may be hydrochloric acid.

Alternatively, the initiator is hydrochloric acid at a concentration of 15 wt%.

In an embodiment of the present application, the molar ratio of the initiator to dodecyldimethylamine can be 1: 2.

In embodiments of the present application, the solvent may be isopropanol or ethanol.

In an embodiment of the present application, the reaction temperature of the solution polymerization reaction may be 90 to 100 ℃.

In an embodiment of the present application, the period of time may be 40 to 50 hours.

It is another object of the present application to provide a water injection well pump-down augmented surfactant solution comprising the above bis-quaternary ammonium cationic Gemini surfactant.

The water injection well pressure-reducing and injection-increasing surfactant solution provided by the application comprises 30-40 parts by mass of the bis-quaternary ammonium cation Gemini surfactant prepared by the method according to any one of claims 1-8 and 70-60 parts by mass of water.

It is yet another object of the present application to provide a method of preparing the above water injection well reduced-pressure augmented injection surfactant solution.

The method for preparing the water injection well pressure-reducing and injection-increasing surfactant solution comprises the step of stirring and mixing the bis-quaternary ammonium cation Gemini surfactant and water in parts by mass to obtain the water injection well pressure-reducing and injection-increasing surfactant solution.

The application has the following beneficial effects:

1. the water injection well pressure-reducing and injection-increasing surfactant solution has low surface tension and interface tension, and when the addition amount of the water injection well pressure-reducing and injection-increasing surfactant is 500mg/L, the oil-liquid interface tension can be smaller than 1;

2. the water injection well pressure-reducing and injection-increasing surfactant solution can increase the contact angle of water drops on a glass slide, so that the wettability of the water drops moves from hydrophilic to oleophilic directions, and the water injection well pressure-reducing and injection-increasing surfactant solution has certain capability of changing the wettability of rocks;

3. the water injection well reduces the pressure and increases the injection of the surfactant solution, so that the water injection pressure can be reduced by 50%; when the water injection pressure is increased to the same value, the injection amount can be increased by 50%.

Additional features and advantages of the application will be set forth in the description which follows, and in part will be obvious from the description, or may be learned by the practice of the application. The objectives and other advantages of the application may be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

Drawings

The accompanying drawings are included to provide a further understanding of the claimed subject matter and are incorporated in and constitute a part of this specification, illustrate embodiments of the subject matter and together with the description serve to explain the principles of the subject matter and not to limit the subject matter.

FIG. 1 is a displacement pressure change curve of 18-1# artificial core after water injection 40PV on site.

Fig. 2 is a plot of the displacement pressure after field injection of water containing the water injection well depressurization augmented surfactant solution of example 2 for # 23 synthetic core injection 60 PV.

Detailed Description

To make the objects, technical solutions and advantages of the present application more apparent, embodiments of the present application will be described in detail below with reference to the accompanying drawings. It should be noted that the embodiments and features of the embodiments in the present application may be arbitrarily combined with each other without conflict.

The experimental procedures used in the following examples are all conventional procedures unless otherwise specified.

Materials, reagents and the like used in the following examples are commercially available unless otherwise specified.

Example 1

Preparation of double quaternary ammonium cation Gemini surfactant

Dodecyl dimethylamine and dodecyl glycidyl ether are added into a 100ml four-neck flask according to the mol ratio of 5:1, then a proper amount of ethanol is added as a solvent, and a condenser pipe and a stirring device are arranged. Adding 1/2 hydrochloric acid with the molar weight of dodecyl dimethylamine and the concentration of 15 wt%, after the white fog in the system disappears, starting a power supply to heat, slowly raising the temperature to 95 ℃, and carrying out reflux reaction for 4 hours. The reaction progress was checked (molar ratio of developing agent ethanol to methanol to acetone was 4:2: l, iodine fumigation developed).

After the reaction is finished, distilling to remove the solvent, washing the unreacted dodecyl dimethylamine by using petroleum ether, and finally recrystallizing by using acetone or ethyl acetate to obtain a white flaky crystal, namely the quaternary ammonium cationic Gemini surfactant.

Example 2

Preparation of surfactant solution for pressure reduction and injection increase of water injection well

And (3) adding 30g of the quaternary ammonium cation Gemini surfactant prepared in the example 1 into a beaker, adding 70g of tap water into the beaker under the stirring condition, and stirring at the speed of 500 rpm for 10 minutes to obtain the water injection well pressure-reducing and injection-increasing surfactant solution.

Test example

1. The injection well depressurization and injection-increase surfactant solution prepared in example 2 was evaluated by the "hanging ring method" and the "core displacement method".

(1) The surface tension and interfacial tension of the water injection well depressurization and injection surfactant solution prepared in example 2 were examined by the "hanging ring method". The test results are shown in table 1.

TABLE 1 Experimental data of surface/interfacial tension of depressurization and injection-increasing surfactant solution for injection well with different addition

As can be seen from Table 1, when the addition amount of the depressurization and injection-increasing surfactant solution for the water injection well is 500mg/L, the oil-liquid interfacial tension can be less than 1, which indicates that the depressurization and injection-increasing surfactant solution for the water injection well prepared in example 2 has better capability of reducing the surface/interfacial tension when the addition amount is more than 500 mg/L.

2. The injection pressure reduction capability of the water injection well pressure reduction and injection increase surfactant solution prepared in example 2 on the core is tested by using a core displacement method. The results are shown in Table 2 and FIGS. 1-2.

TABLE 2 Effect of surfactant concentration on hypotensive Effect

As can be seen from the experimental data in table 2, when four water injection well pressure-reducing and injection-increasing surfactant solutions prepared in example 2 with different concentrations are injected, the pressure is reduced, but the pressure-reducing degree difference of the water injection well pressure-reducing and injection-increasing surfactant solutions with different concentrations is large, and when the concentration is less than 3000mg/l, the pressure-reducing effect is limited; the pressure reduction effect is best when the concentration is 5000mg/l, and the injection pressure can be reduced by 44%; at concentrations above 5000mg/l, the hypotensive effect no longer changes significantly. Therefore, 5000mg/l is the optimal concentration of the injected surfactant solution, and can fully play the role of reducing the pressure and increasing the injection of the surfactant and greatly reduce the injection pressure.

As can be seen from the experimental data of FIGS. 1 and 2, after the water 40PV is injected into the 18-1# artificial rock core injection site, the displacement pressure is increased by one time from 0.0115MPa to 0.023 MPa; after injecting 60PV of the field injection water containing the water injection well depressurization and injection-augmented surfactant solution of example 2 into the 23# artificial core, the displacement pressure was increased by one time from 0.013MPa to 0.026 MPa. After the water injection well pressure-reducing and injection-increasing surfactant in the embodiment 2 is added into the field injection water, the injection amount of the field injection water is increased by 20PV, namely the injection amount is increased by 50%, which shows that the water injection well pressure-reducing and injection-increasing surfactant in the embodiment 2 has a better pressure-reducing and injection-increasing effect.

Although the embodiments disclosed in the present application are described above, the descriptions are only for the convenience of understanding the present application, and are not intended to limit the present application. It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the disclosure as defined by the appended claims.

Claims

1. A method of making a bis-quaternary ammonium cationic Gemini surfactant, the method comprising: under the condition of existence of a solvent and hydrochloric acid, carrying out solution polymerization reaction on dodecyl dimethylamine and dodecyl glycidyl ether, and carrying out reflux reaction at the temperature of 90-100 ℃ for 40-50 hours to obtain the bis-quaternary ammonium cation Gemini surfactant; wherein the feeding molar ratio of the dodecyl dimethylamine to the dodecyl glycidyl ether is 4-6: 1.

2. The process of claim 1, wherein the molar charge ratio of dodecyldimethylamine to dodecanol glycidyl ether is 5: 1.

3. The method of claim 1, wherein the hydrochloric acid is 15 wt% hydrochloric acid.

4. The process of claim 3, wherein the molar ratio of hydrochloric acid to dodecyldimethylamine is 1: 2.

5. The method of claim 1, wherein the solvent is isopropanol or ethanol.

6. A water injection well pressure-reducing and injection-increasing surfactant solution, which comprises 30-40 parts by mass of a bis-quaternary ammonium cation Gemini surfactant prepared according to the method of any one of claims 1-5 and 70-60 parts by mass of water.

7. The method for preparing the water injection well pressure-reducing and injection-increasing surfactant solution according to claim 6 comprises the step of stirring and mixing the parts by mass of the double quaternary ammonium cation Gemini surfactant and water to obtain the water injection well pressure-reducing and injection-increasing surfactant solution.