Supramolecular gas well foaming agent and its application

Abstract

This application discloses a supramolecular gas well foaming agent and its application, belonging to the field of foaming agent technology. The supramolecular gas well foaming agent of this application is formed by the interaction of alkylamidopropyl betaine, alkylolamine, and small molecule organic acid, possessing the chemical structure of formula [i]. This supramolecular gas well foaming agent utilizes the interaction between a polyhydroxyl-structured alkylolamine and a small molecule organic acid to rapidly and efficiently self-assemble into a pseudo-Gemini structure surfactant, and then efficiently self-assembles with the interaction of a betaine-type amphoteric surfactant to form a supramolecular gas well foaming agent. The preparation is simple and low-cost. On the one hand, it endows the prepared supramolecular gas well foaming agent with foaming ability and liquid carrying capacity under harsh environments, resulting in excellent temperature resistance, salt resistance, oil resistance, foaming, and liquid carrying properties. On the other hand, it endows the prepared supramolecular gas well foaming agent system with adjustable rheological properties and viscosity, achieving control over foam performance.

Description

Technical Field

[0001] This application belongs to the field of foaming agent technology, and particularly relates to a supramolecular gas well foaming agent and its application. Background Technology

[0002] Fluid accumulation at the bottom of natural gas wells is a common occurrence during production. If not removed promptly, it can cause severe flooding of the wellbore, leading to a rapid decrease in production or even shutdown. Therefore, it is essential to drain the fluid from the bottom of the well in a timely manner.

[0003] Foam drainage is a method of injecting a foaming agent into the stagnant fluid in a gas well, using the agitation of the natural gas flow to cause the fluid at the bottom of the well to foam and then discharge it from the wellbore in the form of foam. Since the main component of the foaming agent is a surfactant, the development of surfactants for foaming agents is crucial. Currently, relevant technicians have developed Gemini surfactants based on supramolecular interaction theory and, by compounding them with other surfactants, have obtained foaming agents that are temperature-resistant, salt-resistant, and highly tunable. For example, patent CN 104974730 B discloses a high-temperature resistant and high-mineralization foaming agent. It combines a cationic Gemini surfactant, a double-chain long-chain alkyl quaternary ammonium salt (carbon chain carbon number 12-18), with anionic surfactants such as fatty alcohol polyoxyethylene ether sulfate, sodium α-alkenyl sulfonate, or sodium dodecyl sulfate to produce a foaming agent with good high-temperature resistance and high mineralization. Another example is patent application CN 115872891 A, which discloses a surfactant system for foaming. It combines a laboratory-synthesized Gemini anionic surfactant with an amphoteric surfactant to produce a foaming agent with excellent foaming and liquid-carrying properties, while reducing the concentration of the foaming agent used.

[0004] However, the preparation and purification process of the Gemini surfactant complex in the foaming agent components mentioned above is complicated, making it difficult to produce the foaming agent on a large scale, thus limiting its application in gas well foam drainage. Summary of the Invention

[0005] This application discloses a supramolecular gas well foaming agent and its application, thereby solving the technical problems of complex preparation process, high cost and unfavorable large-scale production of composite Gemini surfactant-type foaming agents.

[0006] To achieve the above objectives, the first aspect of this application provides a supramolecular gas well flotation agent. The supramolecular gas well flotation agent of this application possesses the chemical structure of formula [i]:

[0007]

[0008] Wherein, R1 is methyl;

[0009] R2 is C 12 -C 16 Alkyl groups;

[0010] R3 is C 12 -C 16 Alkyl or alkenyl groups.

[0011] In some embodiments, the supramolecular gas well degassing agent of this application is formed by the interaction of alkylamidopropyl betaine, small molecule organic acid and alkyl alcohol amine.

[0012] In some embodiments, the molar ratio of the interaction between the alkylamidopropyl betaine, the small molecule organic acid, and the alkyl alcoholamine is 2:1:2.

[0013] In some embodiments, the chemical structure of the alkylolamine is shown in formula [ii]:

[0014]

[0015]

[0016] In some embodiments, the alkyl alcoholamine is one of dodecyl diisopropanolamine, tetradecyl diisopropanolamine, and hexadecyl diisopropanolamine.

[0017] In some embodiments, the small molecule organic acid is one of fumaric acid, malic acid, isophthalic acid, and terephthalic acid.

[0018] In some embodiments, the alkylamidopropyl betaine is one of dodecylamidopropyl betaine, tetradecylamidopropyl betaine, and hexadecylamidopropyl betaine.

[0019] The second aspect of this application provides the application of the supramolecular gas well foaming agent of this application in oil and gas well foam drainage gas production operations.

[0020] In some embodiments, the application method includes: dissolving the mixture of alkylamidopropyl betaine, small molecule organic acid and alkyl alcohol amine in bottom hole fluid to form a supramolecular gas well foaming agent, wherein the concentration of the supramolecular gas well foaming agent in the bottom hole fluid is 10-30 mM.

[0021] Compared with the prior art, the advantages or beneficial effects of the embodiments of this application include at least the following:

[0022] The supramolecular gas well bubble removal agent provided in this application combines alkylamidopropyl betaine, alkylolamine, and small molecule organic acid. On one hand, it utilizes the interaction between the polyhydroxyl-structured alkylolamine and the small molecule organic acid to rapidly and efficiently self-assemble into a pseudo-Gemini structure surfactant, thus eliminating the need for the preparation and purification of Gemini surfactants and reducing costs, which facilitates industrial production and application. On the other hand, it utilizes the interaction between the pseudo-Gemini structure surfactant and the betaine-type amphoteric surfactant to efficiently self-assemble into a supramolecular gas well bubble removal agent, resulting in a significant synergistic effect between the pseudo-Gemini structure surfactant and the betaine-type amphoteric surfactant, thereby improving the prepared supramolecular gas well bubble removal... The foaming ability and liquid carrying capacity of the agent under harsh environments endow the supramolecular gas well foaming agent with excellent temperature resistance, salt resistance, oil resistance, foaming and liquid carrying properties. Thirdly, the prepared supramolecular gas well foaming agent contains both hydrophilic and hydrophobic groups in its structure, which enables the prepared supramolecular gas well foaming agent to form a dense adsorption layer at the gas-liquid interface, which helps to improve the stability of the foam liquid film and effectively prevents the aggregation and disproportionation of bubbles, thereby enhancing the foam stability. Fourthly, the long-chain alkyl alcohol amine in the supramolecular structure prepared in this application can be reversibly protonated by acid / base, thereby forming aggregates in the bottom hole liquid based on pH response, realizing the regulation of the rheological properties and viscosity of the supramolecular gas well foaming agent system, and realizing the regulation of foam performance. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments recorded in this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 Viscosity curves of the supramolecular gas well foaming agent provided in the embodiments of this application at different shear rates;

[0025] Figure 2 The foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent provided in the embodiments of this application are tested under different conditions, wherein... Figure 2 a represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent in the presence of different amounts of methanol; Figure 2 b represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different condensate oil contents; Figure 2 c represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different temperature conditions. Figure 2 d represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different salinity conditions. Detailed Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] In the following description of this embodiment, the term "and / or" is used to describe the association relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, B existing alone, and A and B existing simultaneously. A and B can be singular or plural. The character " / " generally indicates that the preceding and following related objects have an "or" relationship.

[0028] In the following description of this embodiment, the term "at least one" means one or more, and "more than one" means two or more. "At least one of the following" or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c", can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0029] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The singular forms "a" and "the" as used in the embodiments of this application and the appended claims are also intended to include the plural forms, unless the context clearly indicates otherwise.

[0030] Those skilled in the art should understand that, in the following description of the embodiments of this application, the sequence of numbers does not imply the order of execution. Some or all steps may be executed in parallel or sequentially. 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 this application.

[0031] Those skilled in the art will understand that the numerical ranges in the embodiments of this application should be understood to specifically disclose each intermediate value between the upper and lower limits of the range. Each smaller range between any stated value or intermediate value within a stated range, and any other stated value or intermediate value within said range, is also included within the scope of this invention. The upper and lower limits of these smaller ranges may be independently included or excluded from the range.

[0032] Unless otherwise stated, the technical / scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains. While this application describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may be used in the implementation or testing of this application. All references to this specification are incorporated by way of citation to disclose and describe methods and / or materials associated with those references. In the event of any conflict with any incorporated reference, the content of this specification shall prevail.

[0033] In a first aspect, embodiments of this application provide a supramolecular gas well flotation agent. The supramolecular gas well flotation agent of this application embodiment possesses the chemical structure of formula [i]:

[0034]

[0035] Wherein, R1 is methyl;

[0036] R2 is C 12 -C 16 Alkyl groups;

[0037] R3 is C 12 -C 16 Alkyl or alkenyl groups.

[0038] In this application, the supramolecular gas well bubble draining agent combines alkylamidopropyl betaine, alkylolamine, and small molecule organic acid. On one hand, it utilizes the interaction between the polyhydroxyl-structured alkylolamine and the small molecule organic acid to rapidly and efficiently self-assemble into a pseudo-Gemini structure surfactant. This eliminates the need for the preparation and purification of Gemini surfactants, and the raw materials are readily available, significantly shortening the preparation time and reducing costs, thus promoting industrial production and application. On the other hand, it utilizes the interaction between the pseudo-Gemini structure surfactant and the betaine-type amphoteric surfactant to efficiently self-assemble into a supramolecular gas well bubble draining agent, resulting in a strong synergistic effect between the pseudo-Gemini structure surfactant and the betaine-type amphoteric surfactant. The invention aims to improve the foaming ability and liquid carrying capacity of the prepared supramolecular gas well foaming agent under harsh environments, endowing it with excellent temperature resistance, salt resistance, oil resistance, foaming ability, and liquid carrying capacity. Thirdly, the prepared supramolecular gas well foaming agent structure contains both hydrophilic and hydrophobic groups, enabling it to form a dense adsorption layer at the gas-liquid interface. This helps improve the stability of the foam liquid film and effectively prevents bubble aggregation and disproportionation, thereby enhancing foam stability. Fourthly, the long-chain alkyl alcohol amines in the supramolecular structure prepared in this application can be reversibly protonated by acid / base, thus forming aggregates in the bottom hole liquid based on pH response. This allows for the regulation of the rheological properties and viscosity of the supramolecular gas well foaming agent system, thereby controlling the foam performance.

[0039] In a specific embodiment, the supramolecular gas well degassing agent is preferably formed by the interaction of alkylamidopropyl betaine, small molecule organic acid and alkyl alcohol amine.

[0040] The abundant hydroxyl groups in the alkylolamine structure allow it to readily self-assemble with small-molecule organic acids based on supramolecular forces to form pseudo-Gemini surfactants, which are simple, readily available, and low-cost. Simultaneously, alkylolamines containing long-chain hydrophobic and hydrophilic groups can be reversibly protonated by acids / bases, enabling them to form aggregates in the bottom fluid based on pH response. This allows for the regulation of the rheological properties and viscosity of the supramolecular gas well foaming agent system, thus controlling foam performance. Furthermore, the self-assembly of alkylamidopropyl betaine containing long-chain hydrophobic and hydrophilic groups with alkylolamines can endow the formed supramolecular gas well foaming agent with both hydrophilic and hydrophobic groups, resulting in a synergistic effect between the pseudo-Gemini surfactant and the betaine-type amphoteric surfactant. This enhances the foaming ability and liquid carrying capacity of the prepared supramolecular gas well foaming agent under harsh environments, giving it excellent temperature resistance, salt resistance, oil resistance, foaming properties, and liquid carrying capacity.

[0041] In a specific embodiment, the molar ratio of the interaction between the alkylamidopropyl betaine, the small molecule organic acid, and the alkyl alcohol amine is preferably 2:1:2.

[0042] This molar ratio enables alkylamidopropyl betaine, small molecule organic acids, and alkyl alcoholamines to undergo efficient, rapid, and complete self-assembly, thereby improving the utilization rate of raw materials.

[0043] In a specific embodiment, the chemical structure of the alkyl alcoholamine is shown in formula [ii]:

[0044]

[0045] In this application, the alkylolamine possesses a multi-hydroxyl hydrophilic structure, which can not only efficiently and rapidly form a pseudo-Gemini self-assembled structure with small molecule organic acids through supramolecular interactions, but also allows the pseudo-Gemini self-assembled surfactant to tightly pack at the gas-liquid interface, effectively enhancing the stability of the foam liquid film and effectively preventing bubble aggregation and disproportionation, thereby further enhancing foam stability.

[0046] In a specific embodiment, the alkyl alcoholamine is preferably one of dodecyl diisopropanolamine, tetradecyl diisopropanolamine, and hexadecyl diisopropanolamine.

[0047] The alkylolamine contains long-chain hydrophobic and hydrophilic groups, which enable the prepared supramolecular gas well foaming agent to be tightly packed at the gas-liquid interface, effectively enhancing foam stability.

[0048] In a specific embodiment, the small molecule organic acid is preferably one of fumaric acid, malic acid, isophthalic acid, and terephthalic acid.

[0049] The small molecule organic acids are all dicarboxylic acids, and their carboxyl groups can form intermolecular hydrogen bonds with the hydroxyl groups in alkyl alcoholamines, which improves the structural stability of the pseudo-Gemini self-assembled surfactant, thereby endowing the prepared supramolecular gas well foaming agent with excellent temperature resistance, salt resistance and oil resistance.

[0050] In a specific embodiment, the alkylamidopropyl betaine is preferably one of dodecylamidopropyl betaine, tetradecylamidopropyl betaine, and hexadecylamidopropyl betaine.

[0051] The alkylamidopropyl betaine contains long-chain hydrophobic and hydrophilic groups, which can form intermolecular hydrogen bonds with pseudo-Gemini surfactants, enabling the prepared supramolecular gas well foaming agent to form a dense adsorption layer at the gas-liquid interface. This helps to improve the stability of the foam liquid film and effectively prevents the aggregation and disproportionation of bubbles, thereby enhancing the stability of the foam.

[0052] Secondly, embodiments of this application provide the application of the supramolecular gas well foaming agent in oil and gas well foam drainage and gas production operations. The supramolecular gas well foaming agent possesses excellent temperature resistance, salt resistance, oil resistance, controllable foam properties, and is simple and readily available for preparation, which helps improve the efficiency of oil and gas well foam drainage and gas production operations and meets the performance requirements of harsh downhole environments.

[0053] In a specific embodiment, this application provides a method for applying supramolecular gas well foaming agent, which specifically includes the following steps:

[0054] The mixture of alkylamidopropyl betaine, small molecule organic acid and alkyl alcohol amine is dissolved in the bottom fluid of the well and self-assembled to form a supramolecular gas well foaming agent, wherein the concentration of the supramolecular gas well foaming agent in the bottom fluid is 10-30 mM.

[0055] The technical solution of this application will be further described below with reference to specific embodiments.

[0056] Example 1

[0057] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0058] Dodecylamidopropyl betaine 2mM;

[0059] Fumaric acid 1mM;

[0060] Dodecyl diisopropanolamine 2mM.

[0061] Example 2

[0062] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0063] Tetradecylamidopropyl betaine 2mM;

[0064] Fumaric acid 1mM;

[0065] Tetradecyl diisopropanolamine 2mM.

[0066] Example 3

[0067] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0068] Hexadecylamidopropyl betaine 2mM;

[0069] Fumaric acid 1mM;

[0070] Hexadecyl diisopropanolamine 2mM.

[0071] Example 4

[0072] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0073] Dodecylamidopropyl betaine 2mM;

[0074] isophthalic acid 1mM;

[0075] Dodecyl diisopropanolamine 2mM.

[0076] Example 5

[0077] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0078] Tetradecylamidopropyl betaine 2mM;

[0079] isophthalic acid 1mM;

[0080] Tetradecyl diisopropanolamine 2mM.

[0081] Example 6

[0082] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0083] Hexadecylamidopropyl betaine 2mM;

[0084] isophthalic acid 1mM;

[0085] Hexadecyl diisopropanolamine 2mM.

[0086] Example 7

[0087] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0088] Dodecylamidopropyl betaine 2mM;

[0089] 1 mM terephthalic acid;

[0090] Dodecyl diisopropanolamine 2mM.

[0091] Example 8

[0092] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0093] Tetradecylamidopropyl betaine 2mM;

[0094] 1 mM terephthalic acid;

[0095] Tetradecyl diisopropanolamine 2mM.

[0096] Example 9

[0097] This embodiment provides a supramolecular gas well degassing agent, which is formed by the self-assembly of raw materials in the following molar ratio:

[0098] Hexadecylamidopropyl betaine 2mM;

[0099] 1 mM terephthalic acid;

[0100] Hexadecyl diisopropanolamine 2mM.

[0101] To verify the actual performance of the supramolecular gas well foaming agent of this application, the supramolecular gas well foaming agents of Examples 1-9 were dissolved in clean water and subjected to ultrasonic treatment. The foaming performance was tested according to SY / T 5350-2009 "Evaluation Procedure for Foaming Agents for Drilling Fluids" and the liquid carrying capacity of the foam was tested according to SY / T 7494-2020 "Experimental Evaluation Method for Foaming Agents for Oil and Gas Fields".

[0102] 1.1 The test method for foaming performance includes: foaming volume and half-life are determined by stirring. Take 100 mL of the prepared foaming agent solution (the total concentration of supramolecular gas well foaming agent is 10-30 mM), stir in a high-speed mixer for 3 min, pour the generated foam into a graduated cylinder, and record the maximum foaming volume and half-life (the time required to precipitate 50 mL of solution).

[0103] 1.2 The test method for foam liquid-carrying performance includes: using a foam liquid-carrying performance evaluation device, nitrogen gas is passed through a glass frit core into a glass column, with the gas flow rate controlled at 400 mL / min. Due to the disturbance and propulsion effect of the airflow, the generated foam carries the liquid out of the glass column. The amount of liquid carried out by foaming agent solutions of different concentrations after 9 minutes of aeration is tested.

[0104] 1.3 The test results are detailed in Tables 1 and 2.

[0105] Table 1: Test results of foaming and liquid carrying capacity of supramolecular gas well foaming agents in Examples 1-9 (pH=6.0)

[0106]

[0107] Table 2: Test results of foaming and liquid carrying capacity of supramolecular gas well foaming agents in Examples 1-9 (pH=7.6)

[0108]

[0109]

[0110] A comparison of Tables 1 and 2 shows that after adjusting the pH from 6.0 to 7.6 with NaOH, the foaming volume and half-life of the supramolecular gas well foaming agent of this application are significantly reduced compared to the surfactant solution with a weakly acidic pH. This indicates that under weakly alkaline conditions, long-chain alkyl alcoholamines dissociate from the micelles, the network structure breaks down, and a low-viscosity solution is produced.

[0111] To illustrate the technical effects of the supramolecular gas well foaming agent of this application, comparative examples 1-5 are provided, in which the alkyl alcoholamines in the components of the supramolecular gas well foaming agent of this application are replaced with propylene glycol, glycerol, and butanediol, respectively. The specific comparative examples are as follows:

[0112] Comparative Example 1

[0113] This comparative example provides a foaming agent, which is self-assembled from raw materials in the following molar ratio:

[0114] Dodecylamidopropyl betaine 2mM;

[0115] 1 mM terephthalic acid;

[0116] Propylene glycol 2mM.

[0117] Comparative Example 2

[0118] This comparative example provides a foaming agent, which is self-assembled from raw materials in the following molar ratio:

[0119] Tetradecylamidopropyl betaine 2mM;

[0120] Fumaric acid 1mM;

[0121] Glycerol 2mM.

[0122] Comparative Example 3

[0123] This comparative example provides a foaming agent, which is self-assembled from raw materials in the following molar ratio:

[0124] Hexadecylamidopropyl betaine 2mM;

[0125] Fumaric acid 1mM;

[0126] Butanediol 2mM.

[0127] Comparative Example 4

[0128] This comparative example provides a foaming agent, which is self-assembled from raw materials in the following molar ratio:

[0129] Dodecylamidopropyl betaine 2mM;

[0130] isophthalic acid 1mM;

[0131] Propylene glycol 2mM.

[0132] Comparative Example 5

[0133] This comparative example provides a foaming agent, which is self-assembled from raw materials in the following molar ratio:

[0134] Tetradecylamidopropyl betaine 2mM;

[0135] isophthalic acid 1mM;

[0136] Glycerol 2mM.

[0137] The foaming properties and liquid-carrying properties of the foams prepared in Comparative Examples 1-5 were tested according to the above test methods. The results are detailed in Table 3.

[0138] Table 3: Foaming and liquid carrying capacity test results of comparative examples 1-5 (pH=6.0)

[0139]

[0140]

[0141] A comparison of Tables 1 and 3 shows that when alkyl alcohols are replaced with low-carbon alcohols, the foaming properties of the foaming agent solutions in Comparative Examples 1-5 decrease slightly, while the foam stabilization performance and foam liquid carrying capacity decrease significantly. This indicates that the alkyl alcohols in the supramolecular gas well foaming agent components of this application can more effectively form hydrogen bonds / electrostatic interactions with small molecule acids and betaine surfactants to obtain a supramolecular system, which is beneficial for the surfactant to form a dense adsorption layer at the gas-liquid interface, thereby improving foam stability and liquid carrying capacity.

[0142] 1.4 Viscosity Test

[0143] Shear viscosity tests were conducted on acidic solutions (pH = 6.0) and weakly alkaline solutions (pH = 7.6) of the supramolecular gas well foaming agent of this application. The test method was as follows: at room temperature, the shear rate was tested from 1 to 100 s⁻¹. -1 The viscosity change of the supramolecular gas well foaming agent solution at that time was as follows: Figure 1 As shown. Among them, Figure 1 Viscosity curves of supramolecular gas well foaming agent solution at different shear rates.

[0144] according to Figure 1 It is known that the viscosity of the acidic solution (pH=6.0) of the supramolecular gas well flotation agent of this application fluctuates around 10 mPa·s, while the viscosity of the weakly alkaline solution (NaOH, pH=7.6) of the supramolecular gas well flotation agent of this application fluctuates around 1 mPa·s. Furthermore, across the entire shear rate range, the viscosity of the acidic solution (pH=6.0) of the supramolecular gas well flotation agent of this application is higher than the viscosity of the weakly alkaline solution (NaOH, pH=7.6) containing the supramolecular gas well flotation agent of this application, indicating that the supramolecular gas well flotation agent of this application possesses excellent viscoelasticity and pH responsiveness.

[0145] 1.5 Liquid carrying capacity test under harsh conditions

[0146] The supramolecular gas well foaming agent in Example 5 of Table 1 was evaluated under different salinity, condensate oil content, methanol content, and temperature conditions. The results were as follows: Figure 2 As shown. Among them, Figure 2 The foaming efficiency and liquid carrying efficiency of supramolecular gas well foaming agents under different conditions are specifically analyzed. Figure 2 a represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent in the presence of different amounts of methanol; Figure 2 b represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different condensate oil contents; Figure 2 c represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different temperature conditions. Figure 2 d represents the foaming efficiency and liquid carrying efficiency of the supramolecular gas well foaming agent under different salinity conditions.

[0147] according to Figure 2 It can be seen that, across the entire methanol content range (0-50%), the liquid carrying efficiency of the supramolecular gas well foaming agent in Example 5 showed no significant change; according to Figure 2 As shown in b, compared with the foaming liquid without condensate oil, the presence of condensate oil significantly improves both liquid carrying efficiency and foaming efficiency. Under the condition of 20% condensate oil content, the liquid carrying efficiency reaches its maximum (37.9%); according to... Figure 2 From c, it can be seen that when the temperature increases from 50℃ to 90℃, the liquid carrying efficiency increases from 25.0% to 95.6%; according to Figure 2 As can be seen from d, the salinity has no effect on the foaming ability of the supramolecular gas well foaming agent in Example 5 in the glass column, and has little effect on the liquid carrying capacity of the supramolecular gas well foaming agent in Example 5, indicating that the supramolecular gas well foaming agent solution has excellent salt resistance. Within a salinity range of 0-150 g / L, the foaming efficiency remains at 100%.

[0148] In summary, the supramolecular gas well foaming agent prepared in this application exhibits excellent foaming and liquid-carrying properties even under harsh environmental conditions, and is expected to solve the problem of liquid blockage in gas wells, playing an important role in the field of gas well drainage and gas production. The foaming agent composition described in this invention is of great significance for ensuring gas well production.

[0149] The various embodiments in this specification are described in a progressive manner. The same or similar parts between the various embodiments can be referred to each other. Each embodiment focuses on describing the differences from other embodiments.

[0150] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit this application. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of this application.

Claims

1. A supramolecular gas well foam cleanup agent, characterized in that, It has a chemical structure of formula ] [ ] wherein R1 is methyl; R2is C 12 -C 16 alkyl; R3is C 12 -C 16 alkyl.

2. The supramolecular gas well foamers as claimed in claim 1, wherein, The alkyl amido propyl betaine, alkyl alcohol amine and fumaric acid interact to form.

3. The supramolecular gas well foamers as claimed in claim 2, wherein, The molar ratio of the alkyl amido propyl betaine, fumaric acid and alkyl alcohol amine is 2:1:

2.

4. The supramolecular gas well foamers as claimed in claim 3, wherein, The chemical structure of the alkyl alcohol amine is shown in formula ] [ ]。 5. The supramolecular gas well foamers as claimed in claim 4, wherein, The alkyl alcohol amine is one of dodecyl diisopropyl alcohol amine, tetradecyl diisopropyl alcohol amine and hexadecyl diisopropyl alcohol amine.

6. The supramolecular gas well foamers as claimed in claim 3, wherein, The alkyl amido propyl betaine is one of dodecyl amido propyl betaine, tetradecyl amido propyl betaine and hexadecyl amido propyl betaine.

7. The application of the supramolecular gas well foam agent according to any one of claims 1-6 in the foam drainage gas recovery operation of the oil and gas well.

8. The use of the supramolecular gas well foamers according to any one of claims 1 to 6, characterized in that, The method comprises: The mixture of the alkyl amido propyl betaine, fumaric acid and alkyl alcohol amine is dissolved in the well bottom fluid to self-assemble the supramolecular gas well foam agent, wherein the concentration of the supramolecular gas well foam agent in the well bottom fluid is 10-30 mM.

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