阅读说明：本技术 聚合物微球及其制备方法和应用 (Polymer microsphere and preparation method and application thereof ) 是由 高宏波 于 2021-11-02 设计创作，主要内容包括：本申请提供一种聚合物微球及其制备方法应用,涉及石油开采领域。本申请提供一种聚合物微球,所述聚合物微球由包括如下原料制备而成：引发剂、单体、链转移剂、交联剂、水、油相和乳化剂；其中,所述单体包括第一单体、第二单体、耐温抗剪切单体和耐温抗盐单体；所述第一单体和所述第二单体各自独立地选自丙烯酸或丙烯酰胺中的至少一种,所述耐温抗剪切单体包括N-乙烯基吡咯烷酮,所述耐温抗盐单体包括2-丙烯酰胺-2甲基丙磺酸或烯丙基磺酸钠。本申请的聚合物微球具有良好的抗高温、抗盐、抗剪切等性能,且该聚合物微球的制备方法相对简单,对设备要求低,产品质量容易控制,成本更低,易于推广应用。(The application provides a polymer microsphere and a preparation method and application thereof, relating to the field of oil exploitation. The application provides a polymer microsphere, which is prepared from the following raw materials: initiator, monomer, chain transfer agent, cross-linking agent, water, oil phase and emulsifier; wherein the monomer comprises a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer and a temperature-resistant and salt-resistant monomer; the first monomer and the second monomer are respectively and independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methyl propane sulfonic acid or sodium allyl sulfonate. The polymer microsphere has good high temperature resistance, salt resistance, shear resistance and other properties, and the preparation method of the polymer microsphere is relatively simple, has low requirements on equipment, is easy to control the product quality, has lower cost and is easy to popularize and apply.)

1. The polymer microsphere is characterized by being prepared from the following raw materials: initiator, monomer, chain transfer agent, cross-linking agent, water, oil phase and emulsifier;

wherein the monomer comprises a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer and a temperature-resistant and salt-resistant monomer;

the first monomer and the second monomer are respectively and independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methyl propane sulfonic acid or sodium allyl sulfonate.

2. The polymeric microsphere of claim 1, wherein the chain transfer agent comprises urea; and/or

The cross-linking agent comprises at least one of N-dodecyl acrylamide or octadecyl vinyl ether.

3. The polymeric microspheres of claim 1, wherein the oil phase comprises liquid paraffin No. 10 or liquid paraffin No. 15; and/or

The emulsifier comprises a white oil emulsifier.

4. The polymer microsphere according to any one of claims 1 to 3, wherein the polymer microsphere is prepared from the following raw materials in parts by weight under the action of an initiator:

2-4 parts of a first monomer;

19.5-21.5 parts of a second monomer;

2-3 parts of a temperature-resistant and shear-resistant monomer;

1.5-2 parts of a temperature-resistant salt-resistant monomer;

0.5-1 part of a chain transfer agent;

1-2 parts of a cross-linking agent;

30-35 parts of water;

30-35 parts of an oil phase;

4-6 parts of an emulsifier.

5. The polymeric microsphere of claim 4, wherein the initiator comprises the following components in percentage by weight of the total weight of the first monomer, the second monomer, the temperature and shear resistant monomer, the temperature and salt resistant monomer, the chain transfer agent, the crosslinking agent, the water, the oil phase, and the emulsifier:

1-2% of ammonium persulfate;

0.5 to 1 percent of sodium bisulfite;

1 to 2 percent of azo initiator.

6. A method of making polymeric microspheres, the method comprising:

dissolving a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent and a cross-linking agent in water to obtain a water phase;

adding an initiator into the water phase to carry out initiation polymerization reaction to obtain a colloid, and then shearing the colloid through a shearing reaction kettle and cutting the colloid through a colloid cutting machine to obtain an intermediate;

and mixing the intermediate with an oil phase, and adding an emulsifier for emulsification to obtain the polymer microspheres.

7. The method for preparing the polymer microspheres according to claim 6, wherein the mixing the intermediate with the oil phase and adding the emulsifier for emulsification specifically comprises:

mixing the intermediate and the oil phase, passing through a colloid mill, and then adding an emulsifier into a homogenizer for homogenizing and emulsifying for more than 30 min.

8. The method for preparing polymer microspheres according to claim 6, wherein the polymerization temperature is 30-70 ℃ and the reaction time is 0.5-8 h.

9. The method of any one of claims 6-8, wherein the first monomer and the second monomer are each independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methylpropanesulfonic acid or sodium allylsulfonate;

the chain transfer agent comprises urea;

the cross-linking agent comprises at least one of N-dodecyl acrylamide or octadecyl vinyl ether;

the oil phase comprises No. 10 liquid paraffin or No. 15 liquid paraffin; and/or

The emulsifier comprises a white oil emulsifier.

10. Use of the polymeric microspheres according to any one of claims 1 to 5 or the polymeric microspheres obtained by the method according to any one of claims 6 to 9 in tertiary oil recovery in oil fields.

Technical Field

The application relates to a polymer microsphere and a preparation method and application thereof, belonging to the technical field of oil exploitation.

Background

Petroleum is one of important energy sources in modern industry, is an important source of basic raw materials in chemical industry, and the difficulty of petroleum exploitation gradually increases along with the continuous exploitation of the existing crude oil in an oil field, wherein the water produced by an oil well causes a common problem in the development of the existing oil field. At present, most of domestic oil fields enter a tertiary oil recovery stage successively. In view of the common problems existing in the current oil field exploitation, the techniques of profile control and profile control flooding of the oil field in the high water-cut period need to be researched, the injected water wave and volume are enlarged, and the crude oil recovery rate and the development benefit are improved.

The polymer microsphere is a polymer cross-linked sphere composed of hydrophilic macromolecules synthesized on the ground, is generally formed by polymer monomers, a cross-linking agent, an initiator and the like under the conditions of inverse emulsion and the like, and can effectively enter the deep part of a stratum to play a role in deep profile control due to good migration capacity in the stratum. Particularly, the polymer microspheres have good water absorption expansion performance and visco-elastic performance, can be transported in a porous medium, block large pore channels through the effects of bridging, accumulation and the like, and enable water to flow around through the resistance effect of physical resistance to enlarge the swept volume, so that the profile control effect of deep liquid flow steering is realized. The existing polymer microspheres for profile control are mainly prepared by polymer monomers such as acrylamide, acrylic acid/sodium acrylate and the like or by adding a cross-linking agent. However, the existing preparation process of the polymer microspheres or the performance of the polymer microspheres still needs to be improved, for example, the existing preparation process of the polymer microspheres is complicated, the requirement on equipment is high, the cost is high, and the product quality is not easy to control.

Accordingly, there is still a need for improved polymeric microspheres and methods of making the same in the related art.

Disclosure of Invention

The present invention is directed to solving at least one of the problems of the prior art. Therefore, the invention provides the polymer microsphere and the preparation method and application thereof, the polymer microsphere has good high temperature resistance, salt resistance, shearing resistance and other capabilities, the preparation method of the polymer microsphere is relatively simple, the requirement on equipment is low, the cost is low, the product quality is controllable, and the popularization and the application are facilitated.

According to one aspect of the present application, there is provided a polymer microsphere, which is prepared from the following raw materials: initiator, monomer, chain transfer agent, cross-linking agent, water, oil phase and emulsifier;

wherein the monomer comprises a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer and a temperature-resistant and salt-resistant monomer;

the first monomer and the second monomer are respectively and independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methyl propane sulfonic acid or sodium allyl sulfonate.

In one possible embodiment, the chain transfer agent comprises at least one of urea, thiourea dioxide or thiourea; and/or

The cross-linking agent comprises at least one of N-dodecyl acrylamide or octadecyl vinyl ether.

In one possible embodiment, the oil phase comprises liquid paraffin No. 10 or liquid paraffin No. 15; and/or

The emulsifier comprises a white oil emulsifier.

In a possible embodiment, the polymer microspheres are prepared from the following raw materials in parts by weight under the action of an initiator:

2-4 parts of a first monomer;

19.5-21.5 parts of a second monomer;

2-3 parts of a temperature-resistant and shear-resistant monomer;

1.5-2 parts of a temperature-resistant salt-resistant monomer;

0.5-1 part of a chain transfer agent;

1-2 parts of a cross-linking agent;

30-35 parts of water;

30-35 parts of an oil phase;

4-6 parts of an emulsifier.

In one possible embodiment, the initiator comprises the following components in percentage by weight of the total weight of the first monomer, the second monomer, the temperature-resistant and shear-resistant monomer, the temperature-resistant and salt-resistant monomer, the chain transfer agent, the cross-linking agent, the water, the oil phase and the emulsifier:

1-2% of ammonium persulfate;

0.5 to 1 percent of sodium bisulfite;

1 to 2 percent of azo initiator.

According to another aspect of the present application, there is provided a method of preparing polymeric microspheres, the method comprising:

dissolving a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent and a cross-linking agent in water to obtain a water phase;

adding an initiator into the water phase to carry out initiation polymerization reaction to obtain a colloid, and then shearing the colloid through a shearing reaction kettle and cutting the colloid through a colloid cutting machine to obtain an intermediate;

and mixing the intermediate with an oil phase, and adding an emulsifier for emulsification to obtain the polymer microspheres.

The preparation method of the polymer microsphere is based on the same inventive concept as the polymer microsphere, so that the polymer microsphere at least has the characteristics and advantages of the polymer microsphere.

In a possible embodiment, the mixing of the intermediate with the oil phase and the addition of the emulsifier for emulsification specifically comprises:

mixing the intermediate and the oil phase, passing through a colloid mill, and then adding an emulsifier into a homogenizer for homogenizing and emulsifying for more than 30 min.

In one possible embodiment, the temperature of the polymerization reaction is 30 ℃ to 70 ℃ and the reaction time is 0.5h to 8 h.

In one possible embodiment, the first monomer and the second monomer are each independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methylpropanesulfonic acid or sodium allylsulfonate;

the chain transfer agent comprises urea;

the cross-linking agent comprises at least one of N-dodecyl acrylamide or octadecyl vinyl ether;

the oil phase comprises No. 10 liquid paraffin or No. 15 liquid paraffin; and/or

The emulsifier comprises a white oil emulsifier.

According to another aspect of the present application, there is provided a use of the polymer microsphere or the polymer microsphere prepared by the preparation method in tertiary oil recovery in oil field.

The technical scheme of the invention at least has the following beneficial effects:

the polymer microsphere provided by the embodiment of the invention is mainly prepared from an initiator, a monomer, a chain transfer agent, a cross-linking agent, water, an oil phase and an emulsifier, wherein the monomer comprises a first monomer, a second monomer, a temperature-resistant anti-shearing monomer and a temperature-resistant salt-resistant monomer; the first monomer and the second monomer are respectively and independently selected from at least one of acrylic acid or acrylamide, the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone, and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methyl propane sulfonic acid or sodium allyl sulfonate. Therefore, the polymer microsphere has good high temperature resistance, salt resistance, shearing resistance and other properties, the particle size of the polymer microsphere is more controllable, the suspension property and the dispersibility are better, the water absorption expansion rate and the absorption expansion multiple are moderate, the migration of the microsphere to a deeper part of an oil reservoir is facilitated, the profile control and flooding effect is increased, and the plugging effect is better.

The preparation method of the polymer microsphere provided by the embodiment of the invention is relatively simple, simple and convenient to operate, low in requirements on production equipment, low in cost and easier to control the product quality, so that the preparation method is more beneficial to popularization and application.

Additional aspects and advantages of the present application will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the present application.

Detailed Description

In order to make the purpose, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be clearly and completely described below with reference to the embodiments of the present application, and it should be apparent that the described embodiments are some but not all of the embodiments of the present application. All other embodiments obtained by those skilled in the art without any creative effort based on the technical solutions and the given embodiments provided in the present application belong to the protection scope of the present application. The examples, in which specific conditions are not specified, were conducted under conventional conditions or conditions recommended by the manufacturer. The reagents or instruments used are not indicated by the manufacturer, and are all conventional products available commercially.

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For numerical ranges, one or more new numerical ranges may be obtained by combining the individual values, or by combining the individual values.

It should be noted that the term "and/or"/"used herein is only one kind of association relationship describing associated objects, and means that there may be three relationships, for example, a and/or B, and may mean: a exists alone, A and B exist simultaneously, and B exists alone. As used in the examples of this application and the appended claims, the singular forms "a", "an", and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise.

In the description of the present application, use of the term "at least one of," "at least one of," or other like terms to connote any combination of items listed. For example, if item A, B is listed, the phrase "at least one of A, B" means only a; only B; or A and B. In another example, if item A, B, C is listed, the phrase "at least one of A, B, C" means a only; or only B; only C; a and B (excluding C); a and C (excluding B); b and C (excluding A); or A, B and C. Item a may comprise a single element or multiple elements. Item B may comprise a single element or multiple elements. Item C may comprise a single element or multiple elements.

As will be appreciated by those skilled in the art, as is the background art, the polymer microspheres and the preparation method thereof in the related art have more or less disadvantages and further improvements are desired. For example, chinese patent application No. CN201510683935.9 discloses a polymer microsphere and a preparation method thereof, wherein the method comprises preparing an oil phase and a water phase, adding a part of the oil phase into a reactor, adding the water phase and another part of the oil phase, stirring uniformly, sequentially adding an oxidant aqueous solution and a reducing agent aqueous solution, and reacting at a certain temperature and time to obtain an inverse emulsion of polyacrylamide microspheres. The method has the disadvantages of complex process, high requirements on production equipment, high difficulty in product quality control, high final product cost, loss of the competitiveness of the terminal market and difficulty in popularization. Therefore, in order to avoid the defects of complicated preparation process, high equipment requirement, high cost and difficult control of product quality of the polymer microspheres, the development of novel polymer microspheres and a preparation method thereof are problems which are urgently needed to be solved by related industries.

Based on this, the technical scheme of the embodiment of the application provides a high temperature resistant and salt resistant polymer microsphere and a preparation method and application thereof, the polymer microsphere provided by the technical method of the embodiment of the application has good high temperature resistant, salt resistant, shear resistant and other properties, the preparation method is simple, the operation is simple and convenient, the product quality is easy to control, and the method is suitable for being applied to the field of water plugging of tertiary oil recovery under the conditions of high temperature and high salinity. See below for a description of specific embodiments.

In some embodiments of the present application, there is provided a polymeric microsphere prepared from raw materials comprising: initiator, monomer, chain transfer agent, cross-linking agent, water, oil phase and emulsifier;

wherein the monomer comprises a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer and a temperature-resistant and salt-resistant monomer; the first monomer and the second monomer are each independently selected from at least one of Acrylic Acid (AA) or Acrylamide (AM); that is, the first monomer may be acrylic acid, acrylamide, or a mixture of acrylic acid and acrylamide, and the second monomer may be acrylic acid, acrylamide, or a mixture of acrylic acid and acrylamide;

the temperature-resistant and shear-resistant monomer comprises N-vinyl pyrrolidone (NVP), and the temperature-resistant and salt-resistant monomer comprises 2-acrylamide-2-methyl propane sulfonic Acid (AMPS) or sodium allyl sulfonate.

According to the technical scheme provided by the embodiment of the invention, the polymer microsphere has good performances of high temperature resistance, salt resistance, shear resistance and the like, the particle size of the polymer microsphere is more controllable, the suspension property and the dispersibility are better, the water absorption expansion rate and the absorption expansion multiple are moderate, the migration of the microsphere to a deeper part of an oil reservoir is facilitated, the profile control and flooding effect is increased, and the plugging effect is better. The inventors have analyzed based on this phenomenon and considered that it is possible to: the polymer microsphere of the invention selects proper monomers, chain transfer agent, cross-linking agent, oil phase, emulsifier and other raw materials, under the action of initiator, through the mutual cooperative matching of proper and proper amount of acrylic acid, acrylamide, N-vinyl pyrrolidone, 2-acrylamide-2 methyl propane sulfonic acid or sodium allylsulfonate, chain transfer agent, cross-linking agent, water, oil phase and emulsifier, under the mutual matching and supporting of the functions of all raw material components and the mutual restriction and collocation among proportions, the related performance of the polymer microsphere is improved, the temperature resistance and salt resistance of the polymer microsphere are effectively improved, the shear resistance is enhanced, the content of the effective components of the prepared polymer microsphere is high, the water-absorbing expansion rate and the absorption expansion multiple are moderate, the requirements of tertiary oil recovery, water shutoff and profile control and the like on-site operation of crude oil can be met, the economy is good.

In some embodiments, the water used in the preparation of the polymeric microspheres may be deionized water.

In some embodiments, the first monomer may be Acrylic Acid (AA), which, together with acrylamide, constitutes the main molecular chain and the main side molecular chain of the product as one of the base monomers; the purity of the acrylic acid is required to be more than 99%. In practice, if acrylic acid is difficult or unavailable to purchase, it may be replaced in whole or in part with acrylamide.

In some embodiments, the second monomer may be Acrylamide (AM), which is in solid form and has a water content of less than 12%, and one of the acrylamide as a base monomer together with the acrylamide forms the main molecular chain and the main side molecular chain of the product. In practical application, if the price of acrylamide is too high, part of acrylic acid can be used to replace acrylamide, but the addition amount of acrylic acid should not exceed 50% of the addition amount of acrylamide.

According to the embodiment of the application, the temperature-resistant and shear-resistant monomer is N-vinyl pyrrolidone (NVP), the N-vinyl pyrrolidone is in a liquid state, the content of the N-vinyl pyrrolidone is required to be more than 99%, and the N-vinyl pyrrolidone mainly has the effect of increasing the temperature resistance and the shear resistance of product molecules.

According to the embodiment of the application, the temperature-resistant and salt-resistant monomer is 2-acrylamide-2-methylpropanesulfonic Acid (AMPS) or sodium allylsulfonate, preferably AMPS; AMPS is solid, the purity requirement is more than 98%, and AMPS mainly has the function of increasing the temperature resistance and salt resistance of product molecules.

In some embodiments, the chain transfer agent comprises at least one of urea, thiourea dioxide or thiourea, preferably the chain transfer agent is urea. The chain transfer agent mainly plays a role in controlling the molecular weight of the product to reach the requirement of the product.

In some embodiments, the crosslinking agent is a hydrophobic crosslinking agent that includes at least one of N-dodecyl acrylamide or octadecyl vinyl ether.

In some embodiments, the oil phase may be white oil, and specifically includes liquid paraffin No. 10 or liquid paraffin No. 15. Among them, liquid paraffin No. 10 is also referred to as industrial 10# white oil, and liquid paraffin No. 15 is also referred to as industrial 15# white oil. Liquid paraffin No. 10 or liquid paraffin No. 15 can be obtained by commercially purchasing them.

In some embodiments, the emulsifier comprises a white oil emulsifier. For example, a special white oil emulsifier from the institute for cloud cleaning chemical, Weihai, Shandong, may be used.

In addition, in other embodiments, the oil phase, the emulsifier, the cross-linking agent, etc. are not limited to the above-listed ones, and in case of satisfying the requirements of the polymeric microspheres for temperature and salt resistance, etc., the oil phase, the emulsifier, and the cross-linking agent may also be of other types, which will not be described in detail herein.

Specifically, in some embodiments, the polymer microsphere is prepared from the following raw materials in parts by weight under the action of an initiator; namely, the polymer microspheres are mainly obtained by reacting a reaction system comprising the following components in parts by weight:

2-4 parts of a first monomer; the first monomer may be acrylic acid;

19.5-21.5 parts of a second monomer; the second monomer may be acrylamide;

2-3 parts of a temperature-resistant and shear-resistant monomer; the temperature-resistant and shear-resistant monomer can be N-vinyl pyrrolidone;

1.5-2 parts of a temperature-resistant salt-resistant monomer; the temperature-resistant and salt-resistant monomer is preferably 2-acrylamide-2-methylpropanesulfonic acid;

0.5-1 part of a chain transfer agent; the chain transfer agent is preferably urea;

1-2 parts of a cross-linking agent; the cross-linking agent can be one or two of N-dodecyl acrylamide and octadecyl vinyl ether;

30-35 parts of water;

30-35 parts of an oil phase; the oil phase can be No. 10 liquid paraffin or No. 15 liquid paraffin;

4-6 parts of an emulsifier; the emulsifier can be a special white oil emulsifier.

The initiator comprises the following components in percentage by weight of the total weight of a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent, a cross-linking agent, water, an oil phase and an emulsifier; that is, the initiator, in weight percent of all monomers above, comprises the following components:

1-2% of ammonium persulfate; the ammonium persulfate is a 5% aqueous solution of ammonium persulfate;

0.5 to 1 percent of sodium bisulfite; the sodium bisulfite is 5 percent aqueous solution of sodium bisulfite;

1 to 2 percent of azo initiator; the azo initiator may be azo initiator V50.

Herein, percentages, ratios or parts referred to are by weight unless otherwise indicated. For example, 1% to 2% ammonium persulfate may represent 1% to 2% by weight ammonium persulfate or 1% to 2% by weight ammonium persulfate. The term "part by weight" as used herein means the basic unit of measurement of the ratio of the components in weight, and 1 part may represent any unit mass, and 1 part may represent 1g, 1.68g, or 5g, for example. In addition, herein, the percentages (%) refer to the weight percentage relative to the composition, unless otherwise specified.

According to the embodiment of the present application, the weight part of the first monomer is 2 to 4 parts, and typically, but not limited to, for example, 2 parts, 2.5 parts, 3 parts, 3.5 parts, 4 parts, and any value in a range formed by any two of these points. The second monomer is present in an amount of 19.5 to 21.5 parts by weight, and may be, for example, typically, but not by way of limitation, 19.5 parts, 20 parts, 20.5 parts, 21 parts, 21.5 parts, and any value within a range defined by any two of these values. The amount of the temperature-resistant and shear-resistant monomer is 2 to 3 parts by weight, and may be, for example, typically but not limited to, 2 parts, 2.2 parts, 2.5 parts, 2.6 parts, 2.8 parts, 3 parts, or any two of these values. The amount of the temperature-resistant and salt-resistant monomer is 1.5 to 2 parts by weight, and typically, but not limited to, may be any value in the range of 1.5 parts, 1.6 parts, 1.7 parts, 1.8 parts, 1.9 parts, 2 parts, or any two of these values, for example. The chain transfer agent is used in an amount of 0.5 to 1 part by weight, and may be used typically, but not limited to, 0.5 part, 0.6 part, 0.7 part, 0.8 part, 0.9 part, 1 part, or any value in the range defined by any two of these values. The amount of the crosslinking agent is 1 to 2 parts by weight, and typically, but not limited to, may be any value in the range of 1 part, 1.1 parts, 1.2 parts, 1.4 parts, 1.5 parts, 1.6 parts, 1.8 parts, 2 parts, or any two of these values. The amount of water is 30 to 35 parts by weight, and may be, for example, typically but not limited to, 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, or any value in the range of any two of these values. The oil phase is 30 to 35 parts by weight, and typically, but not limited to, may be any value within a range of 30 parts, 31 parts, 32 parts, 33 parts, 34 parts, 35 parts, or any two of these values. The emulsifier is present in an amount of 4 to 6 parts by weight, and typically, but not limited to, 4 parts, 4.5 parts, 5 parts, 5.5 parts, 6 parts, and any value in the range of any two of these values.

According to some embodiments of the invention, the polymer microspheres have good temperature resistance, salt resistance, shear resistance and other properties by adjusting the types and proportions of the raw material components and cooperating with other components, and the components are in the above range, so that the prepared polymer microspheres have stable properties and are beneficial to improving the plugging effect.

In some embodiments, the polymeric microspheres are obtained by reacting a reaction system comprising, in parts by weight:

3 parts of a first monomer; the first monomer may be acrylic acid;

19.5-21.5 parts of a second monomer; the second monomer may be acrylamide;

3 parts of a temperature-resistant and shear-resistant monomer; the temperature-resistant and shear-resistant monomer can be N-vinyl pyrrolidone;

1.5 parts of temperature-resistant and salt-resistant monomer; the temperature-resistant and salt-resistant monomer is preferably 2-acrylamide-2-methylpropanesulfonic acid;

0.5-1 part of a chain transfer agent; the chain transfer agent is preferably urea;

1-1.5 parts of a cross-linking agent; the cross-linking agent can be one or two of N-dodecyl acrylamide and octadecyl vinyl ether;

30-35 parts of water;

30-35 parts of an oil phase; the oil phase can be No. 10 liquid paraffin or No. 15 liquid paraffin;

5 parts of an emulsifier; the emulsifier can be a special white oil emulsifier.

By reasonably adjusting and optimizing the content of each component in the polymer microsphere, the synergistic cooperation effect among the components is fully exerted, the comprehensive performance of the polymer microsphere is further improved, and the production cost of the polymer microsphere is reduced.

In some embodiments, there is also provided a method of making polymeric microspheres, the method comprising:

dissolving a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent and a cross-linking agent in water to obtain a water phase;

adding an initiator into the water phase to carry out initiation polymerization reaction to obtain a colloid, and then shearing the colloid through a shearing reaction kettle and cutting the colloid through a colloid cutting machine to obtain an intermediate;

and mixing the intermediate with an oil phase, and adding an emulsifier for emulsification to obtain the polymer microspheres.

It should be understood that the preparation method of the polymeric microspheres is based on the same inventive concept as the aforementioned polymeric microspheres, and thus has at least all the features and advantages of the aforementioned polymeric microspheres, and further description of the components of the polymeric microspheres can be referred to the aforementioned description, and further description thereof is omitted.

The embodiment of the invention provides a preparation method for producing the high-temperature-resistant salt-resistant polymer microspheres for tertiary oil recovery at lower cost by relatively simple equipment, relatively few kinds of equipment and relatively complete and simple production process. Therefore, the method has simple process and easy operation, and is suitable for industrial scale production.

In some embodiments, the mixing the intermediate with the oil phase and adding the emulsifier to emulsify specifically includes:

mixing the intermediate and the oil phase, passing through a colloid mill, and then adding an emulsifier into a homogenizer for homogenizing and emulsifying for more than 30 min.

In some embodiments, the polymerization reaction temperature is 30 ℃ to 70 ℃ and the reaction time is 0.5h to 8 h.

Specifically, in some embodiments, a method for preparing polymeric microspheres specifically comprises:

dissolving a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent and a cross-linking agent in water to prepare an aqueous solution, namely obtaining a water phase; then adding an initiator to carry out initiation polymerization reaction to obtain colloid; then shearing the colloid by a shearing reaction kettle and cutting by a colloid cutting machine to obtain an intermediate; mixing the intermediate and oil phase, grinding with colloid mill, and homogenizing and emulsifying with emulsifier in homogenizer at room temperature for more than 30min to obtain polymer microsphere.

The main production equipment adopted by the preparation method comprises: a polymerization shearing reaction kettle, a colloid cutting machine, a colloid mill and a homogenizer.

Compared with the existing preparation method of the polymer microspheres, the preparation method of the polymer microspheres provided by the embodiment of the invention has the advantages that the production process is simplified, the requirements on production equipment are simple, the process is simple, and enterprises with polymer production lines can produce the polymer microspheres by adding several types of equipment.

In some embodiments, the polymer microspheres prepared by the preparation method or the polymer microspheres prepared by the preparation method are applied to tertiary oil recovery in oil fields.

According to application requirements, the polymer microspheres can be directly prepared into aqueous solution with required concentration by water, and can be applied to field operations for improving the recovery ratio of crude oil in tertiary oil recovery operation of an oil field independently or after being compounded with other oil field chemicals.

In order to fully illustrate the relevant properties of the polymeric microspheres provided herein and facilitate understanding of the present invention, multiple sets of experimental verifications were performed herein. The present invention will be further described with reference to specific examples and comparative examples. Those skilled in the art will appreciate that only some of the examples described herein are within the scope of the present application and that any other suitable specific examples are within the scope of the present application.

Example 1

The polymer microsphere of the embodiment is obtained by reacting a reaction system mainly comprising the following components in parts by weight under the action of an initiator:

3 parts of a first monomer; the first monomer is acrylic acid;

19.5 parts of a second monomer; the second monomer is acrylamide;

3 parts of a temperature-resistant and shear-resistant monomer; the heat-resistant anti-shearing monomer is N-vinyl pyrrolidone;

1.5 parts of temperature-resistant and salt-resistant monomer; the temperature-resistant and salt-resistant monomer is 2-acrylamide-2-methylpropanesulfonic acid;

0.5 parts of a chain transfer agent; the chain transfer agent is urea;

1 part of a crosslinking agent; the cross-linking agent is N-dodecyl acrylamide;

30 parts of water;

30 parts of an oil phase; the oil phase is No. 10 liquid paraffin;

5 parts of an emulsifier; the emulsifier is special white oil emulsifier.

The initiator comprises the following components in percentage by weight of all the monomers:

1% ammonium persulfate; the ammonium persulfate is a 5% aqueous solution of ammonium persulfate;

0.5% sodium bisulfite; the sodium bisulfite is 5 percent aqueous solution of sodium bisulfite;

1% of azo initiator; the azo initiator is azo initiator V50.

The preparation method of the polymer microsphere comprises the following steps:

dissolving a first monomer, a second monomer, a temperature-resistant and shear-resistant monomer, a temperature-resistant and salt-resistant monomer, a chain transfer agent and a cross-linking agent in water to prepare an aqueous solution, namely obtaining a water phase; then adding an initiator to carry out initiation polymerization reaction to obtain colloid; then shearing the colloid by a shearing reaction kettle and cutting by a colloid cutting machine to obtain an intermediate; mixing the intermediate and oil phase, grinding with colloid mill, and homogenizing and emulsifying with emulsifier in homogenizer at room temperature for more than 30min to obtain polymer microsphere.

Example 2

Embodiment 2 is basically the same as embodiment 1, and the same parts are not described again, except that:

the polymer microsphere of the embodiment is obtained by reacting a reaction system mainly comprising the following components in parts by weight under the action of an initiator:

4 parts of a first monomer; the first monomer is acrylic acid;

21.5 parts of a second monomer; the second monomer is acrylamide;

3 parts of a temperature-resistant and shear-resistant monomer; the heat-resistant anti-shearing monomer is N-vinyl pyrrolidone;

2 parts of temperature-resistant and salt-resistant monomer; the temperature-resistant and salt-resistant monomer is 2-acrylamide-2-methylpropanesulfonic acid;

1 part of a chain transfer agent; the chain transfer agent is urea;

2 parts of a crosslinking agent; the cross-linking agent is N-dodecyl acrylamide;

35 parts of water;

35 parts of an oil phase; the oil phase is No. 10 liquid paraffin;

6 parts of an emulsifier; the emulsifier is special white oil emulsifier.

Example 3

Embodiment 3 is basically the same as embodiment 1, and the description of the same parts is omitted, except that:

the polymer microsphere of the embodiment is obtained by reacting a reaction system mainly comprising the following components in parts by weight under the action of an initiator:

2 parts of a first monomer; the first monomer is acrylic acid;

20 parts of a second monomer; the second monomer is acrylamide;

2.5 parts of a temperature-resistant and shear-resistant monomer; the heat-resistant anti-shearing monomer is N-vinyl pyrrolidone;

1.8 parts of temperature-resistant and salt-resistant monomer; the temperature-resistant and salt-resistant monomer is 2-acrylamide-2-methylpropanesulfonic acid;

0.8 parts of a chain transfer agent; the chain transfer agent is urea;

1.2 parts of a crosslinking agent; the cross-linking agent is N-dodecyl acrylamide;

32 parts of water;

33 parts of an oil phase; the oil phase is No. 10 liquid paraffin;

5.5 parts of an emulsifier; the emulsifier is special white oil emulsifier.

Example 4

Embodiment 4 is basically the same as embodiment 1, and the description of the same parts is omitted, except that:

the temperature-resistant and salt-resistant monomer is sodium allylsulfonate.

Example 5

Embodiment 5 is basically the same as embodiment 1, and the description of the same parts is omitted, except that:

the oil phase is No. 15 liquid paraffin;

the cross-linking agent is octadecyl vinyl ether.

Example 6

Embodiment 6 is basically the same as embodiment 1, and the description of the same parts is omitted, except that:

the cross-linking agent comprises N-dodecyl acrylamide and octadecyl vinyl ether.

Example 7

Embodiment 7 is basically the same as embodiment 1, and the description of the same parts is omitted, except that:

the initiator comprises the following components in percentage by weight of all the monomers:

2% of ammonium persulfate; the ammonium persulfate is a 5% aqueous solution of ammonium persulfate;

1% sodium bisulfite; the sodium bisulfite is 5 percent aqueous solution of sodium bisulfite;

2% of azo initiator; the azo initiator is azo initiator V50.

Comparative example 1

Comparative example 1 differs from example 1 only in that:

3 parts of N-vinylpyrrolidone are replaced by 3 parts of acrylic acid.

Comparative example 2

Comparative example 2 differs from example 1 only in that:

2 parts of 2-acrylamido-2-methylpropanesulfonic acid are replaced by 3 parts of acrylic acid.

Comparative example 3

Comparative example 3 differs from example 1 only in that:

the polymer microsphere of the embodiment is obtained by reacting a reaction system mainly comprising the following components in parts by weight under the action of an initiator:

1 part of a first monomer; the first monomer is acrylic acid;

25 parts of a second monomer; the second monomer is acrylamide;

0.2 part of temperature-resistant and shear-resistant monomer; the heat-resistant anti-shearing monomer is N-vinyl pyrrolidone;

0.5 part of temperature-resistant salt-resistant monomer; the temperature-resistant and salt-resistant monomer is 2-acrylamide-2-methylpropanesulfonic acid;

0.3 parts of a chain transfer agent; the chain transfer agent is urea;

1 part of a crosslinking agent; the cross-linking agent is N-dodecyl acrylamide;

38 parts of water;

25 parts of an oil phase; the oil phase is No. 10 liquid paraffin;

3 parts of an emulsifier; the emulsifier is special white oil emulsifier.

Performance testing

The polymer microspheres obtained in each example and comparative example were tested for primary particle size using a laser particle sizer and recorded. The polymer microspheres obtained in each example and comparative example are respectively dispersed into 5000mg/L saline (NaCl aqueous solution) to prepare 0.05% solution, the solution is uniformly stirred and subjected to ultrasonic treatment for 30 minutes, the solution is put into a closed container (an aging kettle matched with a roller furnace), the closed container is put into a drying oven, after the closed container is aged at a constant temperature of 90 ℃ for 1 day, 3 days, 5 days, 7 days and 15 days, the particle size distribution is measured by a laser particle sizer, and the expansion multiple of the particle size of the microspheres is calculated. The results are shown in table 1 below.

TABLE 1

From the above, the particle size distribution of the polymer microspheres in the embodiment of the invention is between 3.0 and 53 microns, the water absorption speed of the microspheres in 15 days is uniform, the expansion multiple of the microspheres in 15 days can reach 4.1 times, the initial expansion multiple is low, the expansion speed is slow, the microspheres are favorable for transporting the microspheres to a deeper part of an oil reservoir, and the profile control and flooding effect is improved.

In addition, the polymer microspheres of the embodiments 1 to 7 of the invention have the advantages that the viscosity of the microspheres is continuously increased within 105 to 120 days at 90 ℃, the particle size is expanded, the good plugging effect is realized, and then the polymer with the viscosity is generated through decomposition, so that the deep profile control and flooding effect is realized.

While embodiments of the present application have been shown and described, it will be understood by those of ordinary skill in the art that: various changes, modifications, substitutions and alterations can be made to the embodiments without departing from the principles and spirit of the application, the scope of which is defined by the claims and their equivalents.