CN115975620B - Gas well foam discharging agent and preparation method and application thereof - Google Patents

Abstract

The present application discloses a gas well foaming agent and its preparation method and application, belonging to the technical field of gas well chemical agents. The gas well foaming agent of the present application includes alkyl acylated trimethylammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol, amino acid sodium and solvent water. The compounding of these components can significantly enhance the viscoelasticity of the foam liquid film and the stability of the foam. On the one hand, it can maintain a high liquid carrying capacity under high temperature, high mineralization and high condensate oil, and is suitable for drainage and gas production in deep natural gas wells; on the other hand, the raw materials of the components contained in the gas well foaming agent are easy to obtain and easy to prepare, and no complicated organic synthesis and/or purification process is required, and the degradation performance is good, and it has the advantages of low cost, environmental protection, easy degradation and easy promotion.

Description

A gas well foaming agent and its preparation method and application

Technical Field

The present application belongs to the technical field of gas well chemicals, and in particular relates to a gas well foaming agent and a preparation method and application thereof.

Background technique

Liquid accumulation in gas wells refers to the phenomenon that liquid that cannot be carried out by the natural gas flow accumulates at the bottom of the well during the production process of the gas well. In recent years, with the continuous development of gas fields, most gas wells in China have experienced liquid accumulation in gas wells. Liquid accumulation in gas wells can generate bottom-hole back pressure, resulting in a decrease in gas production or even no gas production, which seriously affects the development and production of gas fields. Therefore, it is necessary to remove the liquid accumulation at the bottom of the well to ensure stable production and increase production of gas wells.

Foam drainage is to add a foaming agent to the liquid in the gas well to produce foaming, dispersion, drag reduction and washing effects in the vertical mixed flow of gas and liquid phases, thereby achieving the purpose of drainage and gas production. It is a common measure to remove the bottom of the well. However, with the exploitation of natural gas wells, the mineralization and condensate content of the bottom of the well have increased significantly, which has seriously reduced the performance of the foaming agent.

In order to treat the bottom-hole liquid accumulation with high mineralization and high condensate content with foam drainage, many high temperature resistant, oil resistant and salt resistant foam drainage agents have been developed in the art. For example, the patent with the announcement number CN 110791273 B shows a composite foam drainage agent, which is composed of anionic surfactant, _CO2 / _N2 switch salt-resistant responsive tertiary amine, polymer AM-NVP-AS, foam stabilizer and ethanol, which can achieve drainage and gas production in the gas well environment with high temperature, high mineralization and high condensate oil, and has the characteristics of good foam stability, long half-life and strong liquid carrying capacity; the patent with the announcement number CN 109681176B discloses an oil-resistant foam drainage agent composition, whose components include alkylamine polyether benzene sulfonate, long-chain polyether nitrogen-containing compound and nanoparticles, which can be used in drainage and gas production of gas wells containing condensate oil, and has the properties of oil resistance, thermal stability, foaming performance and strong liquid carrying capacity.

However, existing high temperature resistant, oil resistant and salt resistant foaming agents generally contain components such as polymers, macromolecules or nanoparticles, generally involving complex organic synthesis and/or purification processes, and have complex preparation processes and high costs. At the same time, some foaming agent components contain ingredients such as sulfonates, which have poor environmental performance and are not conducive to promotion and application.

Summary of the invention

The purpose of the present application is to provide a gas well foaming agent and a preparation method and application thereof, aiming to solve the technical problems of the existing high temperature resistant, oil resistant and salt resistant foaming agents, such as complex synthesis, high cost and difficulty in degradation.

In order to achieve the above application purpose, the technical solution of this application is:

The first aspect of the present application provides a gas well foaming agent, which includes water and the following components dissolved in the water: alkyl acylopropyl trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol and amino acid sodium.

In a preferred implementation of the first aspect, the molar ratio of the alkyl acylation trimethyl ammonium chloride, the amino acid surfactant, the betaine surfactant, the high carbon alcohol and the amino acid sodium is (2-4):(1-3):(1-3):(3-5):(1-10).

In a preferred implementation of the first aspect, the molar ratio of the alkyl acylation trimethyl ammonium chloride, the amino acid surfactant, the betaine surfactant, the high carbon alcohol and the amino acid sodium is (2-4):(1-3):(1-3):(4-5):(4-10).

In a preferred implementation of the first aspect, the alkyl acylation propyltrimethylammonium chloride has a chemical structure shown in the following formula (1):

Wherein, _R1 is any one of _C12 - _C18 alkyl groups.

In a preferred implementation of the first aspect, the amino acid surfactant is any one of sodium lauroyl glutamate, sodium lauroyl glycinate, and sodium lauroyl lysine.

In a preferred implementation of the first aspect, the betaine surfactant has a chemical structure shown in the following formula (2):

Wherein, _R2 is any one of _C12 - _C18 alkyl groups.

In a preferred implementation of the first aspect, the higher alcohol has a chemical structure shown in the following formula (3):

R ₃ -OH

(3)

Wherein, R ₃ is any one of C ₁₀ -C ₁₆ alkyl groups.

In a preferred implementation of the first aspect, the sodium amino acid has a chemical structure shown in the following formula (4):

Wherein, R ₄ and R ₅ are each independently selected from -H or -CH ₂ COONa.

The second aspect of the embodiment of the present application also provides a method for preparing the gas well foaming agent according to the first aspect, which comprises the following steps:

The component raw materials contained in the gas well foaming agent are dissolved in water and subjected to ultrasonic treatment to obtain the gas well foaming agent.

A third aspect of the embodiments of the present application also provides the use of the gas well foaming agent described in the first aspect in water drainage and gas recovery treatment of a natural gas well.

Compared with the prior art, the advantages or beneficial effects of the embodiments of the present application include at least:

The gas well foaming agent provided in the first aspect of the present application is prepared by compounding alkyl acylation trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol and sodium amino acid, wherein the quaternary ammonium cation group contained in the alkyl acylation trimethyl ammonium chloride can form an electrostatic attraction effect with the carboxyl anion group of the amino acid surfactant, betaine surfactant and sodium amino acid; at the same time, the amide group contained in the alkyl acylation trimethyl ammonium chloride can form hydrogen bonds with the hydroxyl group of the amino acid surfactant, the amide group of the betaine surfactant and the hydroxyl group of the high carbon alcohol, so that based on the electrostatic attraction effect and hydrogen bonding, not only the molecules of the alkyl acylation trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol and sodium amino acid are cross-linked, but also a dense and stable interfacial adsorption film is formed at the gas-liquid interface, so that the viscoelasticity of the foam liquid film and the stability of the foam are significantly enhanced. In addition, sodium amino acid has a small molecular structure and is rich in carboxyl groups, which helps it form complexes with high-valent salt ions such as ^Ca2+ and ^Mg2+ , thereby demonstrating an efficient shielding effect on high-valent salt ions, which helps to improve the adaptability of the gas well foaming agent described in the first aspect under high mineralization conditions.

Based on the above advantages, the gas well foaming agent described in the first aspect can, on the one hand, maintain a high liquid carrying capacity under high temperature, high mineralization and high condensate oil, and is suitable for drainage and gas production of single problem gas wells such as high temperature/high mineralization/high condensate oil, and is also suitable for drainage and gas production of complex problem gas wells with high temperature, high mineralization and high condensate oil, and meets the drainage and gas production of deep natural gas wells; on the other hand, the synthesis of the component raw materials contained in the gas well foaming agent is simple and has good degradation performance, and no longer requires complex organic synthesis and/or purification process, and has the advantages of low cost, environmental protection, easy degradation and easy promotion.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following briefly introduces the drawings required for use in the description of the embodiments. Obviously, the drawings described below are only some embodiments recorded in the present application, and for ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

FIG. 1 is a microscopic picture of foam formed by gas well foaming agent solution sample YG1 at different decay times provided in an example of the present application.

Detailed ways

The technical solutions in the embodiments of the present application will be described clearly and completely below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present application.

In the following description of this embodiment, the term "and/or" is used to describe the association relationship of associated objects, indicating that there may be three relationships. For example, A and/or B can represent: A exists alone, B exists alone, and A and B exist at the same time. A and B can be singular or plural. The character "/" generally indicates that the associated objects before and after are in an "or" relationship.

In the following description of this embodiment, the term "at least one" refers to one or more, and "plurality" refers to two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single items or plural items. For example, "at least one of a, b or c", or "at least one of a, b and c", can all represent: a, b, c, a-b (i.e. a and b), a-c, b-c, or a-b-c, where a, b, c can be single or multiple, respectively.

Those skilled in the art should understand that in the following description of the embodiments of the present application, the order of serial numbers does not mean the order of execution, some or all of the steps can be executed in parallel or sequentially, and the execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

The terms used in the embodiments of the present application are only for the purpose of describing specific embodiments, and are not intended to limit the present application. The singular forms "a", "an" and "the" used in the embodiments of the present application and the appended claims are also intended to include plural forms, unless the context clearly indicates other meanings.

In a first aspect, the present invention provides a gas well foaming agent, which includes water and the following components dissolved in the water: alkyl acylopropyl trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol and amino acid sodium.

In view of this, the gas well foaming agent of the embodiment of the present application is formed by dissolving alkyl acylated trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, high carbon alcohol and amino acid sodium in water to form a composite surfactant component, so that they can achieve synergistic effect through cross-linking. Specifically:

On the one hand, the quaternary ammonium cation group contained in the alkyl acylation trimethylammonium chloride can form an electrostatic attraction effect with the carboxyl anion group of the amino acid surfactant, betaine surfactant and sodium amino acid; on the other hand, the amide group contained in the alkyl acylation trimethylammonium chloride can form hydrogen bonds with the hydroxyl group of the amino acid surfactant, the amide group of the betaine surfactant and the hydroxyl group of the high-carbon alcohol. Based on the electrostatic attraction effect and hydrogen bonding, on the one hand, the molecules of the alkyl acylation trimethylammonium chloride, amino acid surfactant, betaine surfactant, high-carbon alcohol and sodium amino acid can be cross-linked, and on the other hand, a dense and stable interfacial adsorption film can be formed at the gas-liquid interface, so that the viscoelasticity of the foam liquid film and the stability of the foam are significantly enhanced.

Thirdly, the amino acid sodium has a small molecular structure and is rich in carboxyl groups, which helps it to form complexes with high-valent salt ions such as Ca ²⁺ and Mg ²⁺ , thereby showing a highly efficient shielding effect on high-valent salt ions, which helps to improve the adaptability of the gas well foaming agent described in the first aspect under high mineralization conditions.

In summary, the invention can maintain a high liquid carrying capacity under high temperature, high mineralization and high condensate, and is suitable for drainage and gas production of single problem gas wells such as high temperature/high mineralization/high condensate, and is also suitable for drainage and gas production of complex problem gas wells such as high temperature, high mineralization and high condensate, and meets the drainage and gas production of deep natural gas wells. On the other hand, the raw materials of the components contained in the gas well foaming agent are easy to obtain and easy to prepare, and do not require complex organic synthesis and/or purification processes, and have the advantages of low cost, environmental protection, easy degradation and easy promotion.

In the embodiments of the present application, the molar ratio of the alkyl acylation trimethyl ammonium chloride, the amino acid surfactant, the betaine surfactant, the high carbon alcohol and the amino acid sodium is preferably (2-4):(1-3):(1-3):(3-5):(1-10).

In the embodiments of the present application, the molar ratio of the alkyl acylation trimethyl ammonium chloride, the amino acid surfactant, the betaine surfactant, the high carbon alcohol and the amino acid sodium is more preferably (2-4):(1-3):(1-3):(4-5):(4-10).

In the embodiment of the present application, the alkyl acylation propyl trimethyl ammonium chloride has a chemical structure shown in the following formula (1):

Wherein, _R1 is preferably any one of _C12 - _C18 alkyl groups. Specifically, according to the different alkyl chains of _R1 , the alkyl acylation trimethyl ammonium chloride is selected from any one of lauroyl acylation trimethyl ammonium chloride, tetradecyl acylation trimethyl ammonium chloride and hexadecyl acylation trimethyl ammonium chloride.

In the embodiment of the present application, the amino acid surfactant is preferably any one of sodium lauroyl glutamate, sodium lauroyl glycine, and sodium lauroyl lysine. On the one hand, these amino acid surfactants contain groups such as carboxyl and amide, which can form electrostatic attraction and hydrogen bonding with other components such as alkyl acylopropyl trimethyl ammonium chloride, thereby achieving synergistic effects through electrostatic attraction and cross-linking of hydrogen bonds. On the other hand, these amino acid surfactants are environmentally friendly and are conducive to promotion and application.

In the embodiment of the present application, the betaine surfactant has a chemical structure shown in the following formula (2):

Wherein, _R2 is any one of _C12 - _C18 alkyl groups. Specifically, according to the different alkyl chains of _R2 , the betaine surfactant is selected from any one of lauryl amidopropyl betaine, tetradecyl amidopropyl betaine and hexadecyl amidopropyl betaine.

In the embodiments of the present application, the high carbon alcohol has a chemical structure shown in the following formula (3):

R ₃ -OH

(3)

Wherein, R ₃ is any one of C ₁₀ -C ₁₆ alkyl groups. Specifically, according to the different alkyl chains of R ₃ , the higher alcohol is selected from any one of dodecanol, tetradecanol and hexadecanol.

In the embodiment of the present application, the sodium amino acid has a chemical structure shown in the following formula (4):

Wherein, _R4 and _R5 are each independently selected from -H or _-CH2COONa . Specifically, according to whether _R4 and _R5 are the same or different, the amino acid sodium is selected from any one of sodium aminoacetate, sodium iminodiacetate and trisodium nitrilotriacetate.

In a second aspect, the present application also provides a method for preparing the above-mentioned gas well foaming agent, which specifically comprises the following steps:

At room temperature, the component raw materials contained in the gas well foaming agent are dissolved in water and subjected to ultrasonic treatment to obtain the gas well foaming agent.

The preparation method provided in the second aspect of the embodiment of the present application can make the various component raw materials fully mixed and dissolved in water, thereby forming a composite surfactant with excellent foam performance through cross-linking, so that the various component raw materials can play a synergistic role, and the gas well foaming agent can maintain a high liquid carrying capacity under high temperature, high mineralization and high condensate oil. It is suitable for drainage and gas production of single problem gas wells such as high temperature/high mineralization/high condensate oil, and is also suitable for drainage and gas production of complex problem gas wells with high temperature, high mineralization and high condensate oil, meeting the drainage and gas production of deep natural gas wells.

The gas well foaming agent provided in the third aspect of the embodiment of the present application is used for drainage and gas production of natural gas wells, based on the characteristics of high stability of generated foam, high temperature resistance, salt resistance, good oil resistance and ideal drainage effect. Therefore, after the gas well foaming agent is used for drainage and gas production of natural gas wells, it can achieve efficient drainage and gas production of natural gas wells, and is suitable for drainage and gas production of single problem gas wells such as high temperature/high mineralization/high condensate oil, as well as drainage and gas production of complex problem gas wells with high temperature, high mineralization and high condensate oil, meeting the drainage and gas production of deep exploitation natural gas wells.

The technical solution of the present invention will be further described below in conjunction with specific embodiments.

Example 1

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, lauroyl trimethyl ammonium chloride, sodium lauroyl glutamate, dodecyl amidopropyl betaine, dodecanol and trisodium nitrilotriacetate were dissolved in 200 mL of clean water at a molar ratio of 2.9 mM: 1.9 mM: 1.2 mM: 4 mM: 10 mM and ultrasonically treated to obtain gas well foaming agent YG1.

Example 2

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, lauroyl trimethyl ammonium chloride, sodium lauroyl glycinate, myristyl amidopropyl betaine, tetradecanol and sodium iminodiacetate were dissolved in 200 mL of clean water at a molar ratio of 2 mM: 1 mM: 1 mM: 3 mM: 8 mM and ultrasonically treated to obtain gas well foaming agent YG2.

Example 3

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, lauroyl trimethyl ammonium chloride, sodium lauroyl lysine, hexadecyl amidopropyl betaine, hexadecanol and trisodium nitrilotriacetate were dissolved in 200 mL of clean water at a molar ratio of 3 mM: 2 mM: 2 mM: 4.5 mM: 10 mM and ultrasonically treated to obtain the gas well foaming agent YG3.

Example 4

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, tetradecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl glutamate, dodecyl amidopropyl betaine, hexadecanol and sodium aminoacetate were dissolved in 200 mL of clean water at a molar ratio of 2.9 mM: 1.9 mM: 1.2 mM: 4 mM: 6 mM and ultrasonically treated to obtain gas well foaming agent YG4.

Example 5

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, hexadecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl glycinate, hexadecyl acylamidopropyl betaine, tetradecanol and trisodium nitrilotriacetate were dissolved in 200 mL of clean water at a molar ratio of 3.5 mM: 2.5 mM: 2 mM: 5 mM: 10 mM and ultrasonically treated to obtain gas well foaming agent YG5.

Example 6

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, myristyl amidopropyl trimethylammonium chloride, sodium lauroyl lysine, myristyl amidopropyl betaine, dodecanol and sodium iminodiacetate were dissolved in 200 mL of clean water at a molar ratio of 4 mM: 3 mM: 3 mM: 5 mM: 9 mM and ultrasonically treated to obtain the gas well foaming agent YG6.

Example 7

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, hexadecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl glycinate, dodecyl amidopropyl betaine, dodecanol and sodium aminoacetate were dissolved in 200 mL of clean water at a molar ratio of 2.9 mM: 1.9 mM: 1.2 mM: 4 mM: 10 mM and ultrasonically treated to obtain gas well foaming agent YG7.

Example 8

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, myristyl amidopropyl trimethylammonium chloride, sodium lauroyl glycinate, myristyl amidopropyl betaine, myristyl alcohol and sodium aminoacetate were dissolved in 200 mL of clean water at a molar ratio of 3.5 mM: 2.5 mM: 2.5 mM: 4 mM: 10 mM and ultrasonically treated to obtain gas well foaming agent YG8.

Example 9

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, hexadecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl glutamate, tetradecyl acylamidopropyl betaine, hexadecanol and sodium iminodiacetate were dissolved in 200 mL of clean water at a molar ratio of 3.5 mM: 2.5 mM: 2 mM: 5 mM: 8 mM and ultrasonically treated to obtain the gas well foaming agent YG9.

Example 10

This embodiment provides a method for preparing a gas well foaming agent, which specifically includes:

At room temperature, hexadecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl glutamate, hexadecyl acylamidopropyl betaine, dodecanol and trisodium nitrilotriacetate were dissolved in 200 mL of clean water at a molar ratio of 4 mM: 3 mM: 2.5 mM: 4 mM: 4 mM and ultrasonically treated to obtain gas well foaming agent YG10.

In order to verify the actual performance of the gas well foaming agent YG1-YG10 prepared in the examples of this application, the foaming performance, foam stabilization performance and liquid carrying performance of the gas well foaming agent YG1-YG10 were tested, specifically including:

1. Test the foaming and stabilizing properties of gas well foaming agents YG1-YG10 in accordance with SY/T 5350-2009 "Evaluation Procedure for Foaming Agents for Drilling Fluids". The specific test process is as follows:

The foaming volume and half-life were measured by stirring method: 100 mL of the prepared gas well foaming agent was stirred in a high-speed stirrer for 3 min at a speed of 7000 rpm. The foam was poured into a measuring cylinder to test the maximum foaming volume and half-life (the time used to precipitate 50 mL of solution).

2. Test the liquid carrying performance of gas well foaming agent YG1-YG10 according to SY/T 7494-2020 "Experimental Evaluation Method of Foaming Agent for Oil and Gas Fields". The specific test process is as follows: Use a foam liquid carrying evaluation device, use nitrogen to disperse into microbubbles through a glass sand core and pass into a glass column. The gas flow rate is controlled at 400mL/min, and the generated foam carries the liquid out of the column. Test the amount of liquid carried out with the foam when different concentrations of foaming agent solutions are passed through nitrogen for 9 minutes.

Test conditions: clean water (mineralization = 0 mg/L), no condensate and room temperature (25°C);

The test results are shown in the following Table 1. Table 1 shows the test results of the foaming, foam stabilization and liquid carrying performance of the gas well foaming agents YG1-YG10 according to the embodiments of the present application.

Table 1 - Foaming, foam stabilization and liquid carrying performance of gas well foaming agents YG1-YG10 in clean water and room temperature

Gas well foaming agent Foaming volume/mL Half-life/min Liquid carrying rate/% Gas well foaming agent YG1 455 25 28.8 Gas well foaming agent YG2 430 twenty three 30.2 Gas well foaming agent YG3 450 30 33.5 Gas well foaming agent YG4 445 28 29.5 Gas well foaming agent YG5 435 32 33.5 Gas well foaming agent YG6 465 33 37.3 Gas well foaming agent YG7 440 25 28.9 Gas well foaming agent YG8 450 28 30.2 Gas well foaming agent YG9 445 35 32.5 Gas well foaming agent YG10 455 38 33.2

It can be seen from Table 1 that the gas well foaming agent prepared in the embodiment of the present application has excellent foaming, foam stabilization and liquid carrying capabilities in the clean water system. Among them, the foaming performance and liquid carrying performance of the gas well foaming agent YG6 are relatively the best, indicating that the composite surfactant formed by dissolving tetradecyl acylamidopropyl trimethylammonium chloride, sodium lauroyl lysine, tetradecyl acylamidopropyl betaine, dodecanol and sodium iminodiacetate in water at a molar ratio of 4mM:3mM:3mM:5mM:9mM has the best performance.

The present application also tests the foaming, foam stabilization and liquid carrying performance of the gas well foaming agent YG1 prepared in the examples of the present application under high salinity, condensate oil and high temperature conditions. The test conditions are shown in Table 2 below.

Table 2 - Test conditions

project Clean water mineralization/mg/L Clear water condensate content (v/v)/% Test temperature/℃ Test condition 1 330000 0 25 Test condition 2 0 50 25 Test condition 3 0 0 90

The test results are shown in Table 3 below. Table 3 shows the foaming, foam stabilization and liquid carrying performance of the gas well foaming agent YG1 under the test conditions shown in Table 2.

Table 3 - Test results under high mineralization, high condensate and high temperature conditions

Gas well foaming agent Foaming volume/mL Half-life/min Liquid carrying rate/% Test 1 450 20 33.8 Test 2 420 twenty three 32.0 Test 3 / / 32.5

It can be seen from Table 3 that the gas well foaming agent YG1 maintains good foaming, foam stabilization and liquid carrying performance under high salinity, high condensate content and high temperature conditions. This shows that the gas well foaming agent prepared in the embodiment of the present application is suitable for drainage and gas production in gas wells with high temperature, high salinity and high condensate content, and meets the drainage and gas production requirements of deep natural gas wells.

FIG1 shows a microscopic picture of foam formed by the gas well foaming agent solution sample YG1 at different decay times (room temperature, scale bar is 1.0 mm).

According to FIG. 1 , it can be seen that the foam generated by the gas well foaming agent YG1 still has a thick liquid film after decaying for 45 minutes, indicating that the gas well foaming agent YG1 has a high foam stabilizing property, indicating that it has good liquid holding and carrying properties.

The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other, and each embodiment focuses on the differences from other embodiments.

The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions recorded in the aforementioned embodiments may still be modified, or some or all of the technical features therein may be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims (6)

1. A gas well foam discharging agent comprising water and the following components dissolved in the water: alkyl acyl propyl trimethyl ammonium chloride, amino acid surfactant, betaine surfactant, higher alcohols and sodium amino acid;

Wherein the molar ratio of the alkyl acyl propyl trimethyl ammonium chloride to the amino acid surfactant to the betaine surfactant to the high carbon alcohol to the amino acid sodium is (2-4): 1-3-5): 1-10;

the amino acid surfactant is any one of sodium lauroyl glutamate, sodium lauroyl glycinate and sodium lauroyl lysine;

The betaine surfactant has a chemical structure shown in the following formula (2):

(2)

In the formula (2), R ₂ is any one of alkyl groups of C _12-C₁₈;

the sodium amino acid has a chemical structure shown in the following formula (4):

(4)

In formula (4), R ₄ and R ₅ are each independently selected from-H or-CH ₂ COONa.

2. The gas well foam-removing agent according to claim 1, wherein the molar ratio of the alkyl acyl propyl trimethyl ammonium chloride, the amino acid surfactant, the betaine surfactant, the higher alcohol and the sodium amino acid is (2-4): 1-3): 4-5: 4-10.

3. A gas well foam discharging agent according to claim 1 or 2, wherein said alkylacyl propyl trimethyl ammonium chloride has a chemical structure represented by the following formula (1):

(1)

In formula (1), R ₁ is any one of alkyl groups of C _12-C₁₈.

4. A gas well foam discharging agent according to claim 1 or 2, wherein said higher alcohol has a chemical structure represented by the following formula (3):

R_3-OH (3)

In formula (3), R ₃ is any one of alkyl groups of C _10-C₁₆.

5. A method of preparing a gas well foam-displacement agent according to any one of claims 1 to 4, comprising the steps of: and dissolving the component raw materials contained in the gas well foam discharging agent in water and performing ultrasonic treatment to obtain the gas well foam discharging agent.

6. Use of a gas well foam drainage agent according to any one of claims 1 to 4 in drainage and production treatments of natural gas wells.