CN111848864B

CN111848864B - Amphiphilic copolymer and preparation method and application thereof

Info

Publication number: CN111848864B
Application number: CN202010736063.9A
Authority: CN
Inventors: 王金剑; 陈斌刚; 张静; 王耀国
Original assignee: Ningbo Fengcheng Advanced Energy Materials Research Institute
Current assignee: Ningbo Fengcheng Advanced Energy Materials Research Institute Co ltd
Priority date: 2020-07-28
Filing date: 2020-07-28
Publication date: 2022-07-01
Anticipated expiration: 2040-07-28
Also published as: CN111848864A

Abstract

The application discloses an amphiphilic copolymer, a preparation method and application thereof. The amphipathic copolymer is composed of structural units represented by formula i, formula ii, and formula iii. The copolymer has good effect in the viscosity reduction process of thick oil. The thick oil viscosity reducer with the content of the amphiphilic copolymer of 0.1-1.0 wt% has a viscosity reducing effect of 90-99% on thick oil with the viscosity of 500-50000mPa & s.

Description

Amphiphilic copolymer and preparation method and application thereof

Technical Field

The application relates to an amphiphilic copolymer, a preparation method and application thereof, and belongs to the technical field of oilfield exploitation.

Background

At present, the exploitation of common thin oil resources is more and more difficult, and along with the slow increase of the reserves of conventional crude oil development, the exploitation of thick oil resources is very critical to relieving the annual reduction of the exploitation amount of thin oil resources and energy crisis. The total output of the thick oil resources in China only accounts for about ten percent of the total output of all crude oil in China, and the average thick oil recovery rate is less than 20 percent, so the development potential is very large. However, the thick oil has the characteristics of high density, high viscosity and difficult flowing due to the relatively high content of colloid asphaltene and low content of straight-chain alkane, and the exploitation faces huge difficulty. The key point that the thickened oil can be smoothly exploited from the stratum to the ground is that the high viscosity of the thickened oil can be reduced, so that the thickened oil is easy to flow from difficulty in flowing, and the reduction of the viscosity of the thickened oil is almost a basic idea for the research and development of all thickened oil exploitation technologies.

Among the common viscosity reduction methods for thick oil, the heating viscosity reduction method has large energy consumption, the dilution method is limited by the source of thin oil, and the modifying viscosity reduction technology has the defects that the screening of a catalyst is very difficult, the viscosity reduction of the oil-soluble viscosity reduction technology is poor, and the microorganism viscosity reduction technology cannot be applied to the high-temperature and high-salinity oil deposit environment. The emulsification viscosity reduction method has wider application field, good viscosity reduction effect, simple operation, low cost and quick effect, so the research on the emulsification viscosity reduction technology becomes a great hotspot of the current thick oil viscosity reduction technology.

In the aspect of the existing water-soluble thick oil emulsifying viscosity reducer, the existing water-soluble thick oil emulsifying viscosity reducer is mainly a compound viscosity reducer, and a large amount of research and application are already carried out on the compound viscosity reducer. However, the complex viscosity reducer often faces the problem of poor compatibility in practical application, and a large amount of compatibility screening and verification need to be performed according to oil reservoir conditions and component conditions. The preparation methods of the water-soluble amphiphilic copolymer for emulsifying and viscosity reduction of the thick oil have more existing methods, and in the methods, an organic phase is adopted as a solvent, or raw materials are self-prepared, or the sources are limited or the cost is higher, or the process is complex, so that the method is not suitable for industrial production or large-scale application and popularization.

Disclosure of Invention

According to one aspect of the present application, an amphipathic copolymer is provided, which has good viscosity reduction effect in viscosity reduction of thick oil.

An amphipathic copolymer comprising structural units represented by formula i, formula ii, and formula iii;

wherein, in formula i, R₁Is a structural unit formed after double bonds in a substance A are opened, wherein the substance A is any one of alpha-sodium olefin sulfonate, sodium oleate, potassium oleate and sodium linoleate;

in formula ii, R₂Is selected from-NH₂、*-OH、*-ONa、*-OK、*-OC₅H₁₁、*-OC₆H₅、*-OC₇H₇、*-OC₁₈H₃₇Any one of (a);

in formula iii, R₃Is selected from-H or-CH₃Any one of (a); r₄Is selected from-₂-*、*-COOC₂H₄Any one of; r is₅Is selected from-₃、*-C₃H₅、*-C₇H₇Any one of (a);

x is the mass percentage of the structural unit represented by the formula i in the amphiphilic copolymer;

y is the mass percentage content of the structural unit represented by the formula ii in the amphiphilic copolymer;

z is the mass percentage of the structural unit represented by formula iii in the amphiphilic copolymer;

the value range of x is more than or equal to 10.0% and less than or equal to 90.0%;

the value range of y is more than or equal to 0.0% and less than or equal to 80.0%;

the value range of z is more than or equal to 0.0% and less than or equal to 70.0%;

10％≤y+z≤90％，x+y+z＝100％。

specifically, the amphiphilic copolymer is selected from any one of substances with a structural formula shown in a formula I;

wherein x, y and z respectively represent the mass percentage content of different structural units in the amphiphilic copolymer.

Preferably, the value range of x is 10-50;

the value range of y is 30-60;

the value range of z is 20-40;

the value range of y + z is 20-50.

Optionally, the amphipathic copolymer has a viscosity average molecular weight of 10 to 1000 ten thousand.

Preferably, the amphiphilic copolymer has a viscosity average molecular weight of 10 to 100 ten thousand.

Specifically, in the present application, when y is 0, the amphiphilic copolymer is selected from any one of substances having a structural formula represented by formula I-1;

wherein in the formula I-1, the value range of x is more than or equal to 30.0% and less than or equal to 90.0%; the value range of z is more than or equal to 10.0 percent and less than or equal to 70.0 percent.

In the present application, when z is 0, the amphiphilic copolymer is selected from any one of substances having a structural formula represented by formula I-2;

wherein in the formula I-2, the value range of x is more than or equal to 20.0% and less than or equal to 90.0%; the value range of y is more than or equal to 10.0 percent and less than or equal to 80.0 percent.

The copolymers in the present application are amphiphilic copolymers.

According to another aspect of the present application, there is also provided a method for preparing the above amphipathic copolymer, comprising: heating and reacting the mixture in the presence of an initiator and a water phase to obtain the amphiphilic copolymer;

the mixture contains a raw material I, and the raw material I is a substance A;

the mixture also contains a raw material II, and the raw material II is selected from at least one of a substance B and a substance C;

wherein the substance A is selected from any one of sodium alpha-olefin sulfonate, sodium oleate, potassium oleate and sodium linoleate;

the substance B is selected from any one of substances with a structural formula shown in a formula II;

wherein, in formula II, R₂' is selected from the group consisting of-NH₂、*-OH、*-ONa、*-OK、*-OC₅H₁₁、*-OC₆H₅、*-OC₇H₇、*-OC₁₈H₃₇Any one of (a);

the substance C is selected from any one of substances with a structural formula shown in a formula III;

wherein, in formula III, R₃' is selected from-H or-CH₃Any one of (a);

R₄' is selected from ` -CH₂-*、*-COOC₂H₄Any one of;

R₅' is selected from ` -CH₃、*-C₃H₅、*-C₇H₇Any one of (a);

X^-is selected from F^-、Cl^-、Br^-、I^-Any one of the above.

Specifically, in the present application, the mixture further contains water as a solvent.

Optionally, the substance B is selected from any one of acrylamide, acrylic acid, sodium acrylate, potassium acrylate, amyl acrylate, phenyl acrylate, benzyl acrylate and octadecyl acrylate;

the substance C is selected from any one of dimethyl diallyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride and methacryloyloxyethyl dimethyl benzyl ammonium chloride.

Optionally, the initiator is selected from any one of potassium persulfate, sodium persulfate, and ammonium persulfate.

Optionally, the mass ratio of the substance A to the substance B to the substance C is 1-9: 0 to 8: 0 to 7; the mass ratio of the raw material I to the raw material II is 1-9: 1 to 9.

Optionally, the mass ratio of the sum of the raw materials I and II to the initiator is 1: 0.001 to 0.02.

Optionally, the reaction conditions are: reaction temperature: 70-85 ℃; the reaction time is 2-8 h.

Specifically, the upper limit of the reaction temperature is independently selected from 75 ℃, 80 ℃ and 85 ℃; the lower limit of the reaction temperature is independently selected from 70 ℃, 75 ℃ and 80 ℃.

The upper limit of the reaction time is selected from 3h, 5h, 6h and 8 h; the lower limit of the reaction time is selected from 2h, 3h, 5h and 6 h.

Optionally, the preparation method comprises:

s100, adding the raw material I into a reactor I, and placing the reactor I into an oil bath pan;

s200, deoxidizing the aqueous solution a containing the raw material II to obtain a solution a;

s300, deoxidizing the aqueous solution b containing the initiator to obtain a solution b;

s400, adding the solution a obtained in the step S200 into the reactor I, heating and stirring to obtain a solution c;

s500, dropwise adding the solution b into the solution c, heating, and reacting to obtain the amphiphilic copolymer.

Alternatively, the conditions of heating and stirring in step S400 are: the stirring speed is 150-500 r/min, and the temperature is 35-50 ℃.

Alternatively, in step S500, the dropping time is 5 to 10 minutes.

According to a third aspect of the present application, there is also provided a thick oil viscosity reducer comprising the amphipathic copolymer as described above and the amphipathic copolymer obtained by any one of the preparation methods described above.

Optionally, the concentration of the amphiphilic copolymer in the thick oil viscosity reducer is 0.1-1.0 wt%.

According to a fourth aspect of the present application, there is also provided a preparation method of the thick oil viscosity reducer, wherein the preparation method comprises:

a) preparing simulated mineralized water of an oil field;

b) and diluting the amphiphilic copolymer by using the oilfield simulated mineralized water to obtain the thickened oil viscosity reducer.

Specifically, the mineralization degree of the simulated mineralized water in the oil field in the step a) is 3% of NaCl and 0.3% of CaCl₂。

The beneficial effects that this application can produce include:

1) the amphiphilic copolymer provided by the application has a good effect in the viscosity reduction process of thick oil. The thick oil viscosity reducer with the content of the amphiphilic copolymer of 0.1-1.0 wt% has a viscosity reducing effect of 90-99% on thick oil with the viscosity of 500-50000mPa & s.

2) According to the preparation method of the amphiphilic copolymer, the amphiphilic copolymer with the obvious viscosity reduction effect on the thick oil is prepared by adopting cheap and easily-obtained raw materials and adopting a one-step aqueous free radical polymerization method, and the defects of limited raw material sources, high price, complex process, serious three wastes and pollution and the like existing in the traditional preparation process are overcome. The preparation method of the water-soluble amphiphilic copolymer is simple, short in time, free of environmental pollution and wide in raw material source, and the amphiphilic copolymer has a good viscosity reduction effect on thick oil.

Drawings

FIG. 1 shows IR characterization data for sample # 2 in one embodiment of the present application.

Detailed Description

The present application will be described in detail with reference to examples, but the present application is not limited to these examples.

The raw materials in the examples of the present application were purchased commercially, unless otherwise specified.

The invention aims to provide an amphipathic copolymer prepared by a one-step water-phase free radical polymerization method (shown as a formula (1)) and application thereof in viscosity reduction of thick oil. The molecular structural formula of the amphiphilic copolymer is shown as a formula (2), wherein the mass percentage of each structural unit of the copolymer is 10.0-90.0% of x, 0.0-80.0% of y, 0.0-70.0% of z, more than or equal to 10% and less than or equal to 90% of y and z, and more than or equal to 100% of x + y + z;

wherein R1 is one of sodium alpha-olefin sulfonate, sodium oleate, potassium oleate and sodium linoleate₂is-NH₂、-OH、-ONa、-OK、-OC₅H₁₁、OC₆H₅、OC₇H₇、OC₁₈H₃₇One of (1), R₃Is H or CH₃One of (1), R₄Is CH₂、COOC₂H₄、COOC₃H₆One of (1), R₅Is CH₃、C₃H₅、C₇H₇One of (1);

wherein the relative molecular weight of the amphiphilic copolymer is 50-1000 ten thousand;

wherein 0.1-1.0% of the amphiphilic copolymer has the viscosity reduction effect of 90-99% on the thick oil with the viscosity of 500-50000mPa & s.

The invention provides a method for preparing an amphiphilic copolymer by a one-step reaction aqueous phase free radical polymerization method, which specifically comprises the following steps:

adding a purchased industrial-grade raw material A (alpha-sodium olefin sulfonate or sodium oleate or potassium oleate or sodium linoleate) into a round-bottom flask, and placing the round-bottom flask into an oil bath;

adding a purchased industrial raw material B (acrylamide, acrylic acid, sodium acrylate, potassium acrylate, amyl acrylate, phenyl acrylate, benzyl acrylate or octadecyl acrylate) into a beaker, adding a purchased industrial raw material C (dimethyl diallyl ammonium chloride, acryloyloxyethyl trimethyl ammonium chloride or methacryloyloxyethyl dimethyl benzyl ammonium chloride) into the beaker, adding a proper amount of water, stirring and dissolving, and introducing nitrogen to remove oxygen;

adding an initiator into a beaker, adding a proper amount of water, stirring and dissolving, and introducing nitrogen to remove oxygen;

step (4) adding the mixture obtained in the step (2) into the round-bottom flask obtained in the step (1), mechanically stirring and heating;

and (5) adding the solution in the step (3) into a dropping funnel on the round-bottomed flask in the step (1), dropping the solution in the step (3) into the round-bottomed flask in the step (1), heating, and reacting for a period of time to obtain the amphiphilic copolymer.

The relevant content in the technical scheme of the preparation method is explained as follows:

1. the mass of the raw material A in the step (1) is 1-9 g;

2. in the step (2), the mass of the raw material B is 0-8g, the mass of the raw material C is 0-7g, the sum of the mass of the raw material B and the raw material C is 1-9g, the weight of water is 95mL, and oxygen is removed for 20-40 minutes;

3. in the step (3), the initiator is one of potassium persulfate, sodium persulfate and ammonium persulfate, the mass of the initiator is 0.02-0.2g, the mass of water is 5mL, and oxygen is removed for 20-40 minutes;

4. in the step (4), the stirring speed is 150-500 r, and the temperature is 35-50 ℃;

5. in the step (5), the dripping time is 5-10 minutes, the temperature is 70-85 ℃, and the reaction time is 2-8 hours.

The viscosity reduction effect evaluation of the amphiphilic copolymer in the thickened oil is carried out, and the experimental method refers to the technical requirement of the thickened oil viscosity reducer of the China oil and gas industry standard Q/SH0055-2007, and specifically comprises the following steps:

preparing simulated mineralized water in an oil field;

taking a proper amount of amphiphilic copolymer, and diluting with the simulated mineralized water in the step (1);

weighing 21g of thickened oil sample in a beaker, and adding 9g of the diluent in the step (2);

step (4), placing the beaker in the step (3) into a constant-temperature water bath at 50 ℃ and keeping the temperature for 1 hour;

step (5) the apparent viscosity of the sample in step (4) at 50 ℃ was measured using a DV2TLV type viscometer manufactured by Brookfield corporation.

The contents of the above-described viscosity-reducing effect evaluation measurement are explained below:

1. the mineralization degree of the mineralized water in the step (1) is 3 percent of NaCl and 0.3 percent of CaCl₂；

2. The concentration of the amphiphilic copolymer in the step (2) is 0.1-1.0%;

3. and (5) selecting a No. 0 rotor for apparent viscosity measurement, wherein the rotating speed is 6 revolutions.

Example 11 preparation of copolymer #

Step 1, adding 2g of alpha-sodium alkenyl sulfonate into a round-bottom flask, and placing the round-bottom flask into an oil bath;

step 2, sequentially adding 6g of acrylamide and 2g of dimethyl diallyl ammonium chloride into the beaker I, adding 85ml of water, introducing nitrogen to remove oxygen for 20min, and obtaining a solution a;

step 3, adding 0.05g of initiator sodium persulfate into a beaker II, adding 5ml of water for dissolving, introducing nitrogen for deoxygenation for 20min to obtain a solution b;

step 4, adding the solution a obtained in the step 2 into the round-bottom flask obtained in the step 1, and heating and stirring at 40 ℃ under the condition of 200 revolutions per minute to obtain a solution c;

and 5, adding the solution b in the step 3 into a dropping funnel above the round-bottom flask in the step (1), dropwise adding the solution b into the solution c, finishing dropwise adding for 5min, and reacting for 5h at 80 ℃ to obtain a copolymer which is recorded as sample No. 1.

(remark: AOS-AM-DMDAAC ternary)

Example 22 preparation of # copolymer

Step 1, adding 5g of alpha-sodium alkenyl sulfonate into a round-bottom flask, and placing the round-bottom flask into an oil bath pan;

step 2, adding 5g of acrylamide into a beaker I, adding 85ml of water, introducing nitrogen to remove oxygen for 20min to obtain a solution a;

step 3, adding 0.03g of initiator sodium persulfate into a beaker II, adding 5ml of water for dissolving, introducing nitrogen for deoxygenation for 20min to obtain a solution b;

step 4, adding the solution a obtained in the step 2 into the round-bottom flask obtained in the step 1, and heating and stirring at 40 ℃ under the condition of 300 revolutions per minute to obtain a solution c;

and 5, adding the solution b in the step 3 into a dropping funnel above the round-bottom flask in the step 1, dropwise adding the solution b into the solution c, dropwise adding for 7min, and reacting for 8h at 70 ℃ to obtain a copolymer which is recorded as sample No. 2.

(remark: AOS-AM binary)

Example 33 preparation of copolymer

Step 1, adding 2g of sodium oleate into a round-bottom flask, and placing the round-bottom flask into an oil bath pan;

step 2, adding 8g of acrylamide into a beaker I, adding 85ml of water, introducing nitrogen to remove oxygen for 20min to obtain a solution a;

and 5, adding the solution b in the step 3 into a dropping funnel above the round-bottom flask in the step (1), dropwise adding the solution b into the solution c, finishing dropwise adding for 5min, and reacting for 5h at 80 ℃ to obtain a copolymer which is recorded as a sample No. 3.

(remark: SO-AM binary)

Example 44 preparation of copolymer

step 2, adding 5g of dimethyl diallyl ammonium chloride into the beaker I, adding 85ml of water, introducing nitrogen to remove oxygen for 20min to obtain a solution a;

step 3, adding 0.01g of initiator sodium persulfate into a beaker II, adding 5ml of water for dissolving, introducing nitrogen for deoxygenation for 20min to obtain a solution b;

and 5, adding the solution b in the step 3 into a dropping funnel above the round-bottom flask in the step (1), dropwise adding the solution b into the solution c, finishing dropwise adding for 5min, and reacting for 5h at 80 ℃ to obtain a copolymer which is recorded as a sample No. 4.

(remark: AOS-DMDAAC binary)

EXAMPLE 5 characterization of the substance

Taking sample # 2 as a representative, the infrared data is shown in FIG. 1, and it can be seen that the copolymer obtained from sample # 2 has the following structural formula:

wherein x is 50% and y is 50%;

the viscosity average molecular weight of the copolymer was 16 ten thousand.

Example 6 preparation of viscosity reducer for heavy oil and Performance test thereof

Step (ii) of(1): preparing the simulated mineralized water of the oil field, wherein the mineralization degree is 3 percent of NaCl and 0.3 percent of CaCl₂；

Step (2): taking a proper amount of sample, and diluting with simulated mineralized water in an oil field to obtain the thick oil viscosity reducer, wherein the content of the copolymer in the thick oil viscosity reducer is 0.1-1.0 wt%.

And (3) viscosity reduction performance test:

weighing 21g of thick oil sample in a beaker, and adding 9g of the diluent (namely the thick oil viscosity reducer) in the step (2); placing the beaker into a constant-temperature water bath at the temperature of 50 ℃ and keeping the temperature for 1 hour; the apparent viscosity of the sample at 50 ℃ was measured using a viscometer of the DV2TLV type manufactured by Brookfield corporation.

Thick oil sample: 1# -Clarity heavy oil, 2# -Zhonghai oil Caofen heavy oil, and 3# -Shengli oil field heavy oil.

The test result shows that: the thick oil viscosity reducer with the copolymer content of 0.1-1.0 wt% has a viscosity reducing effect of 90-99% on thick oil with the viscosity of 500-50000mPa & s.

Wherein, for thick oil No. 1, sample No. 1 has good viscosity reduction effect when the concentration is higher than 1.0 wt%, sample No. 2 has good viscosity reduction effect when the concentration is in the range of 0.1-1.0 wt%, sample No. 3 has good viscosity reduction effect when the concentration is in the range of 0.2-1.0 wt%, and sample No. 4 has poor viscosity reduction effect on the thick oil.

The viscosity reduction effect on the thick oil is about 85% for thick oil No. 2, sample No. 1 and sample No. 2; both sample # 3 and sample # 4 had a viscosity reducing effect of 90% or more, and sample # 4 was superior to sample # 3.

The viscosity reduction effect on the thick oil can reach more than 99% for thick oil No. 3, sample No. 1 and sample No. 2, and the sample No. 1 is superior to the sample No. 2; the viscosity reducing effect of sample 3# and sample 4# on the thick oil is general.

Although the present application has been described with reference to a few embodiments, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the application as defined by the appended claims.

Claims

1. An amphipathic copolymer, wherein said amphipathic copolymer is comprised of structural units represented by formula i, formula ii, and formula iii;

in formula ii, R₂Is selected from-NH₂、*-OH、*-ONa、*-OK、*-OC₅H₁₁、*-OC₆H₅、*-OC₇H₇、*-OC₁₈H₃₇Any one of (a) to (b);

in formula iii, R₃Is selected from-H or-CH₃Any one of (a); r₄Is selected from-₂-*、*-COOC₂H₄Any one of; r₅Is selected from-₃、*-C₃H₅、*-C₇H₇Any one of (a);

the value range of y is more than 0.0 percent and less than or equal to 80.0 percent;

the value range of z is more than 0.0 percent and less than or equal to 70.0 percent;

10％≤y+z≤90％，x+y+z＝100％。

2. the amphipathic copolymer of claim 1, wherein the amphipathic copolymer has a viscosity average molecular weight of 10 to 1000 ten thousand.

3. A process for the preparation of an amphiphilic copolymer according to claim 1 or 2, characterized in that it comprises: heating and reacting the mixture in the presence of an initiator and a water phase to obtain the amphiphilic copolymer;

the mixture contains a raw material I, and the raw material I is a substance A;

wherein, in the formula III, R₃' is selected from-H or-CH₃Any one of (a);

R₄' is selected from ` -CH₂-*、*-COOC₂H₄Any one of;

R₅' is selected from ` -CH₃、*-C₃H₅、*-C₇H₇Any one of (a);

X^-is selected from F^-、Cl^-、Br^-、I^-Any one of the above.

4. The preparation method according to claim 3, wherein the substance B is any one selected from acrylamide, acrylic acid, sodium acrylate, potassium acrylate, amyl acrylate, phenyl acrylate, benzyl acrylate, and stearyl acrylate;

5. The production method according to claim 3, wherein the initiator is selected from any one of potassium persulfate, sodium persulfate, and ammonium persulfate.

6. The preparation method according to claim 3, wherein the mass ratio of the substance A to the substance B to the substance C is 1-9: 0-8: 0 to 7; and the number of the first and second electrodes,

the mass ratio of the raw material I to the raw material II is 1-9: 1 to 9.

7. The preparation method according to claim 6, wherein the mass ratio of the sum of the raw materials I and II to the initiator is 1: 0.001 to 0.02.

8. The method according to claim 3, wherein the reaction conditions are as follows: the reaction temperature is 70-85 ℃; the reaction time is 2-8 h.

9. The production method according to claim 3, characterized by comprising:

s500, dropwise adding the solution b into the solution c, heating and reacting to obtain the amphiphilic copolymer.

10. A viscosity reducer for thick oil, which comprises the amphipathic copolymer as defined in claim 1 or 2 and the amphipathic copolymer obtained by the preparation method as defined in any one of claims 3 to 8.

11. The thick oil viscosity reducer according to claim 10, wherein the concentration of the amphipathic copolymer in the thick oil viscosity reducer is 0.1-1.0 wt%.

12. The method for preparing the thick oil viscosity reducer according to claim 10, wherein the method comprises the following steps:

a) preparing simulated mineralized water of an oil field;