A Gemini anionic surfactant, a foaming surfactant / foaming agent containing the same, and preparation and application thereof

Abstract

The present invention discloses an anionic surfactant, a foaming surfactant / foaming agent containing the anionic surfactant, and the preparation and application thereof. The gemini anionic surfactant is selected from at least one of the compounds represented by formula (I): R 1 Selected from C 7 ~C 41 Hydrocarbon or C 7 ~C 41 Substituted hydrocarbon group, repeated R 1 The same or different; a is any integer from 0 to 8; R 6 Selected from ‑COO ‑ ,‑SO 3 ‑ 、OSO 3 ‑ ,‑R 7 COO ‑ ,‑R 7 SO 3 ‑ or ‑R 7 OSO 3 ‑ , R 7 Selected from C 1 ~C 6 The alkylene group, repeated R 6 The system of the present invention contains multiple hydrophilic head groups with positive and negative charges, which can accurately control the electrostatic force between surfactant molecules, so that the foaming agent has both excellent foaming and stabilizing properties and very strong liquid carrying capacity.

Description

Technical Field

[0001] The present invention belongs to the field of surfactants, and in particular relates to anionic surfactants, and specifically relates to anionic surfactants, a foaming surfactant / foaming agent containing the anionic surfactant, and the preparation and application thereof. Background Art

[0002] After gas well exploitation, there are generally problems of rapid production decline and obvious water production, which seriously affect the production and stable production of gas fields. Foam drainage gas production is a drainage gas production technology that has developed rapidly at home and abroad in recent years. It has the advantages of simple equipment, convenient construction, low cost, wide applicable well depth range, and no impact on the normal production of gas wells. Foam drainage is to inject foam drainage agent into the well through the oil pipe or the annulus of the oil casing, and produce foam with a certain stability under the stirring of the airflow. The liquid phase of the slip deposit in the pipe turns into foam, changing the relative density of the fluid in the low part of the pipe. The continuously produced gas phase drives the foam out of the wellbore, thereby discharging the accumulated liquid in the well and achieving the purpose of drainage and gas production.

[0003] Since the 1960s, foreign countries have started to develop foam drainage agents, and most of them use surfactants such as anionic sulfonates and non-ionic alkylphenol polyoxyethylene ethers. At present, most foam drainage agents used for drainage and gas production use a multi-component system to enhance the stability of a single foam. US7122509 reported a high-temperature foam drainage agent formula, which uses anionic surfactants and amine neutralization research ideas to improve the temperature resistance of the system, but the patent does not involve reports on drainage effects and usage concentrations. CN102212348A discloses a salt-resistant and methanol-resistant foam drainage agent, the weight percentage of each component is: cocamidopropyl betaine 20-40%, amine oxide 45-65%, α-olefin sulfonate 5-20%, triethanolamine 5-15%, fluorocarbon surfactant 0.2-2%, methanol 0-5%, can withstand a mineralization degree of 180,000, and the foam agent dosage is 5000ppm, but the agent contains fluorocarbon surfactants, which not only greatly increases the cost but also has a greater impact on the environment.

[0004] The slow-release technology has been reported in the field of gas field foaming. CN104342096 and CN103937479 invented a slow-release foaming agent, which is composed of natural compounds such as soapberry essence, fatty alcohol polyoxyethylene ether AEO18 and polylauroyl diethanolamine as foaming components, and polyvinyl alcohol and acrylic resin as slow-release materials. It has good oil resistance, salt resistance and liquid carrying effects. However, the foaming component in the formula is mainly non-ionic surfactant fatty alcohol polyoxyethylene ether AEO18, which has the problem of easy turbidity at high temperature and insufficient foaming liquid carrying capacity. In order to achieve the purpose of slow release, the proportion of slow-release material used is as high as 60%, and the residual amount at the bottom of the well is large and the degradation time is long; CN106 753303 discloses an anti-oil slow-release solid foam drainage agent for gas wells, wherein the foaming component is composed of amide-containing sulfonic acid betaine, amide-containing carboxylic acid betaine and coconut oil diethanolamine, accounting for 30-50%, and the slow-release material is acrylic resin, accounting for 20-35%. The slow-release material ratio in this formula is high and the temperature resistance is poor, and there is no result of liquid carrying amount and liquid carrying rate; CN106190080A discloses a spherical solid foam drainage agent for natural gas undulating horizontal wells, wherein the foaming agent is an anionic / non-ionic surfactant combination of sodium dodecyl sulfate and fatty alcohol polyoxyethylene ether, but the formula does not provide foaming performance, liquid carrying performance, and the applicable temperature and mineralization range.

[0005] The foaming agents reported above are generally single-chain surfactants, and gemini-type foaming agents are rarely reported; the amount of slow-release materials used is large, the variety is small, and the high concentration of foaming agents used is the main factor restricting the development of gas well foam drainage technology. Summary of the invention

[0006] The technical problem to be solved by the present invention is that the existing foaming agent has a high instantaneous concentration and discontinuous liquid carrying due to its rapid dissolution. A gemini anionic surfactant, a composition containing the same, and its preparation and application are provided. The present invention is applied to gas well drainage and gas production, has very good liquid carrying, foaming and foam stabilization performance under formation conditions, has the advantages of long foaming action time, low use concentration, etc.

[0007] One of the objects of the present invention is to provide a gemini anionic surfactant, which is selected from at least one of the compounds represented by formula (I):

[0008]

[0009] In formula (I), R1 is selected from C7 to C 41 Hydrocarbon or C7~C 41 The repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C8 hydrocarbon group or a C1-C8 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from C1-C 15a is any integer from 0 to 8; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C6 alkylene groups, and repeated R6 are the same or different; M is hydrogen, a metal ion or a cationic group.

[0010] In a preferred embodiment, in formula (I), R1 is selected from C7 to C 31 Hydrocarbon or C7~C 31 The repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C5 hydrocarbon group or a C1-C5 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from C2-C 10 a is any integer from 0 to 6; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C4 alkylene groups, and repeated R6 are the same or different; M is hydrogen, a metal ion or a cationic group.

[0011] Wherein, the cationic group may be an amino group or a substituted amino group.

[0012] In a further preferred embodiment, in formula (I), R1 is selected from C7 to C 21 Hydrocarbon or C7~C 21 wherein the repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C3 hydrocarbon group or a C1-C3 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from a C2-C6 straight-chain alkylene group or a branched alkylene group; a is any integer from 0 to 3; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C2 alkylene groups, and repeated R6 are the same or different; M is hydrogen, an alkali metal ion or a formula NR8(R9)(R 10 )(R 11 ) shown in the group, R8, R9, R10 , R 11 Each is independently selected from hydrogen, a hydrocarbon group or a substituted hydrocarbon group (preferably a hydroxyl substituted hydrocarbon group). 10 , R 11 are each independently selected from hydrogen, (CH2) e OH or (CH2) f CH3, wherein e is any integer from 2 to 4, and f is any integer from 0 to 2.

[0013] In the present invention, the gemini anionic surfactant contains multiple hydrophilic head groups with positive and negative charges, which can accurately regulate the electrostatic force between surfactant molecules, so that the foaming agent using it has both excellent foaming and stabilizing properties and very strong liquid carrying capacity; the number of negatively charged hydrophilic head groups is greater than the number of positively charged hydrophilic head groups, so that the system as a whole is negatively charged, and the adsorption retention in sandstone gas reservoirs is small, which improves the use efficiency of the foaming agent; the critical micelle concentration of the gemini anionic surfactant is often about 1 order of magnitude lower than that of the single-chain surfactant with the same carbon chain. After compounding with the zwitterionic surfactant, due to the electrostatic attraction of the positive and negative ion head groups, the interface efficiency is further improved, so that the critical micelle concentration of the foaming agent using it can be reduced by 1 to 2 orders of magnitude lower than that of the single agent. The low critical micelle concentration can reduce the concentration of the foaming agent used, and improve the economy of the foaming agent. In addition, the retention of the amide group in the molecular structure can avoid complex chemical reactions such as hydrogenation reduction, reduce the preparation cost of the foaming agent using it, and can be applied to other gas wells except ultra-deep wells and deep wells.

[0014] The second object of the present invention is to provide a method for preparing a gemini anionic surfactant, preferably used for preparing the anionic surfactant described in one of the objects of the present invention, the preparation method comprising:

[0015] (1) Utilize H2N[R4NH] a R5NH2 reacts with CH(R2)=C(R3)R6R0 to obtain the aminocarboxylate intermediate R0R6CH(R3)CH(R2)HN[R4NH] a R5NHCH(R2)CH(R3)R6R0, wherein R6 is selected from -COO-, -SO3-, OSO3-, -R7COO-, -R7SO3- or -R7OSO3-, R7 is selected from a C1-C6 alkylene group, R0 is selected from a hydrocarbon group or a substituted hydrocarbon group, and R2, R3, R4 and R5 have the same definitions as in formula (I);

[0016] (2) subjecting the aminocarboxylate to saponification to obtain an amino salt MR6CH(R3)CH(R2)HN[R4NH] aR5NHCH(R2)CH(R3)R6M, wherein M has the same definition as in formula (I);

[0017] (3) reacting the amine salt with R1COX to obtain a compound represented by formula (I), wherein X is selected from a halogen element and R1 has the same definition as in formula (I).

[0018] In a preferred embodiment, in step (1), H2N[R4NH] a R5NH2 is mixed with a solvent, and CH(R2)=C(R3)R6R0 is added dropwise thereto for reaction. After the reaction is completed, unreacted raw materials and solvent are removed to obtain an aminocarboxylate intermediate.

[0019] In a preferred embodiment, in step (1), the solvent is selected from an organic solvent, preferably at least one selected from acetone, diethyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, and propylene glycol diethyl ether.

[0020] In a further preferred embodiment, in step (1), the solvent and H2N[R4NH] a R a The weight dosage ratio of NH2 is (2-10):1, preferably (4-8):1.

[0021] In a preferred embodiment, in step (1), the reaction temperature is 30 to 100° C., preferably 40 to 90° C.; and / or the reaction time is 1 h to 8 h; and / or unreacted raw materials and solvents are removed by reduced pressure.

[0022] For example, in step (1), the reaction temperature is 40°C, 50°C, 60°C, 70°C, 80°C or 90°C; and / or the reaction time is 1 h, 2 h, 3 h, 4 h, 5 h, 6 h, 7 h or 8 h.

[0023] In a preferred embodiment, in step (1), H2N[R4NH] a The molar ratio of R5NH2 to CH(R2)=C(R3)R6R0 is 1:(1-6), preferably 1:(2-4).

[0024] For example, in step (1), H2N[R4NH] a The molar ratio of R5NH2 to CH(R2)=C(R3)R6R0 is 1:1, 1:2, 1:3, 1:4, 1:5 or 1:6.

[0025] In a preferred embodiment, in step (2), the saponification treatment is carried out in an alkaline solution containing alcohol, and the amine salt is obtained by filtration.

[0026] In a further preferred embodiment, in step (2), the alcohol is selected from at least one of methanol, ethanol, isopropanol and propanol.

[0027] In a further preferred embodiment, in step (2), the pH value of the alkaline solution is 11 to 14, preferably 12 to 13; and / or the saponification treatment is carried out under heating reflux. Wherein, the alkali is selected from sodium hydroxide and / or potassium hydroxide.

[0028] The saponification conditions are not particularly limited, and any saponification conditions disclosed in the prior art may be used as long as the ester can be converted into a salt.

[0029] In a preferred embodiment, in step (3), the amine salt is mixed with a solvent, the pH is adjusted to 8 to 11, preferably 9 to 10, and then R1COX is added dropwise to carry out the reaction.

[0030] In a further preferred embodiment, in step (3), the solvent is selected from at least one of acetone, diethyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, and propylene glycol diethyl ether.

[0031] In a further preferred embodiment, the reaction temperature is -10 to 80°C and the reaction time is 2 h to 10 h.

[0032] For example, in step (3), the reaction temperature is -10°C, 0°C, 10°C, 20°C, 30°C, 40°C, 50°C, 60°C, 70°C or 80°C; the reaction time is 2h, 3h, 4h, 5h, 6h, 7h, 8h, 9h or 10h.

[0033] In a preferred embodiment, in step (3), the molar ratio of the amine salt to R1COX is (0.9-1.3):1, preferably (0.95-1.05):1, for example 1:1.

[0034] For example, in step (3), the molar ratio of the amine salt to R1COX is 0.9:1, 0.95:1, 1:1, 1.1:1, 1.2:1 or 1.3:1.

[0035] In a preferred embodiment, in steps (1) to (3), R1 is selected from C6 to C 40 Hydrocarbon or C6~C 40 and / or, R2 and R3 are each independently selected from hydrogen, a C1-C8 hydrocarbon group or a C1-C8 substituted hydrocarbon group; and / or, R4 and R5 are each independently selected from a C1-C 15a is any integer from 0 to 8; and / or R6 is selected from -COO-, -SO3-, OSO3-, -R7COO-, -R7SO3- or -R7OSO3-, and R7 is selected from C1 to C6 alkylene groups; and / or M is hydrogen, a metal ion or a cationic group; and / or R0 is selected from a hydrocarbon group or a substituted hydrocarbon group; and / or X is selected from a halogen.

[0036] In a further preferred embodiment, in steps (1) to (3), R1 is selected from C7 to C 31 Hydrocarbon or C7~C 31 and / or, R2 and R3 are each independently selected from hydrogen, a C1-C5 hydrocarbon group or a C1-C5 substituted hydrocarbon group; and / or, R4 and R5 are each independently selected from C2-C 10 a is any integer from 0 to 6; and / or R6 is selected from -COO-, -SO3-, OSO3-, -R7COO-, -R7SO3- or -R7OSO3-, and R7 is selected from C1 to C4 alkylene; and / or M is hydrogen, a metal ion or a cationic group; and / or R0 is selected from C1 to C 10 Hydrocarbon or C1~C 10 and / or, X is selected from bromine or chlorine.

[0037] In a further preferred embodiment, in steps (1) to (3), R1 is selected from C7 to C 21 Hydrocarbon or C7~C 21 substituted hydrocarbon group; and / or, R2 and R3 are each independently selected from hydrogen, a hydrocarbon group of C1 to C3 or a substituted hydrocarbon group of C1 to C3; and / or, R4 and R5 are each independently selected from a straight-chain alkylene group or a branched alkylene group of C2 to C6; and / or, a is any integer from 0 to 3; and / or, R6 is selected from -COO-, -SO3-, OSO3-, -R7COO-, -R7SO3- or -R7OSO3-, and R7 is selected from a C1 to C2 alkylene group; and / or, M is hydrogen, an alkali metal or a compound of the formula NR8(R9)(R 10 )(R 11 ) shown in the group, R8, R9, R 10 , R 11 Each is independently selected from hydrogen, hydrocarbon group or substituted hydrocarbon group (preferably hydroxy substituted hydrocarbon group); and / or, R0 is selected from C1-C3 hydrocarbon group or C1-C3 substituted hydrocarbon group; and / or, X is selected from bromine or chlorine.

[0038] The third object of the present invention is to provide a gemini anionic surfactant obtained by the preparation method described in the second object of the present invention.

[0039] A fourth object of the present invention is to provide a foaming surfactant, comprising the gemini anionic surfactant and the zwitterionic surfactant described in one of the objects of the present invention.

[0040] In a preferred embodiment, the zwitterionic surfactant is selected from at least one of the compounds represented by formula (II):

[0041]

[0042] In formula (II), R4' is selected from C1 to C 40 Hydrocarbon or C1~C 40 R5' and R6' are each independently selected from a hydrocarbon group, a substituted hydrocarbon group, an aryl group or a substituted aryl group; R7' is selected from an alkylene group or a substituted alkylene group; m is the number of propoxy groups added, m = 0 to 50; n is the number of ethoxy groups added, n = 0 to 50; j = 0 or 1; Y - Selected from COO - 、SO3 - or OSO3 - .

[0043] In a further preferred embodiment, in formula (II), R4' is selected from C4 to C 32 Hydrocarbon or C4~C 32 R5' and R6' are each independently selected from (CH2) c OH, (CH2) d CH3 or C6H5CH2, c=any integer in the range of 2 to 4, d=any integer in the range of 0 to 5; R7' is selected from C1 to C5 alkylene groups or C1 to C5 substituted alkylene groups; m is the number of propoxy groups added, m=0 to 10; n is the number of ethoxy groups added, n=0 to 20; j=0 or 1; Y - Selected from COO - 、SO3 - or OSO3 - .

[0044] In a further preferred embodiment, in formula (II), R4' is selected from C8 to C 24 Hydrocarbon or C8~C 24 R5' and R6' are each independently selected from (CH2) c OH, (CH2) d CH3 or C6H5CH2, c=any integer in the range of 2 to 4, d=any integer in the range of 0 to 2; R7' is selected from C1 to C3 alkylene or C1 to C3 substituted alkylene; m is the number of propoxy groups added, m=0 to 5; n is the number of ethoxy groups added, n=0 to 10; j=0 or 1; Y - Selected from COO- or SO3 - .

[0045] In a preferred embodiment, the molar ratio of the gemini surfactant to the zwitterionic surfactant is 1:(0.1-10), preferably 1:(0.2-5).

[0046] For example, the molar ratio of the gemini surfactant to the zwitterionic surfactant is 1:0.1, 1:0.2, 1:0.5, 1:1, 1:2, 1:3, 1:4, 1:5, 1:6, 1:7, 1:8, 1:9 or 1:10.

[0047] The fifth object of the present invention is to provide a foaming agent, which includes the foaming surfactant described in the fourth object of the present invention as well as a solid filler, a binder and an optional sustained-release material.

[0048] The foaming agent may be coated with the sustained-release material or may not be coated with the sustained-release material.

[0049] In a preferred embodiment, the solid filler is selected from at least one of carboxylates, carbonates, bicarbonates, sulfates, bisulfates, phosphates, borates, and metal halides.

[0050] In a further preferred embodiment, the solid filler is selected from at least one of formates, acetates, tartaric acid and salts, citric acid and salts, phthalic acid and salts, gallic acid and salts, carbonates, bicarbonates, sulfates, phosphates, borates, metal halides, urea, and biuret.

[0051] In a further preferred embodiment, the solid filler is selected from at least one of sodium carbonate, sodium bicarbonate, sodium borate, sodium chloride, sodium acetate, tartaric acid, sodium tartrate, citric acid, sodium citrate, potassium phthalate, urea, and biuret.

[0052] In a preferred embodiment, the binder is at least one of polyacrylamide, guar gum, cellulose, starch, and polyethylene glycol.

[0053] In a further preferred embodiment, the adhesive is selected from at least one of dextrin, epoxy resin, polyacrylamide, starch, cellulose, and polyethylene glycol.

[0054] In a further preferred embodiment, the adhesive is selected from at least one of polyacrylamide, starch and polyethylene glycol.

[0055] In a preferred embodiment, the sustained-release material is a membrane, which is a membrane formed of a breathable material having micro-nano pores, or a membrane formed of a polymer material that slowly hydrolyzes and / or dissolves under bottom-hole conditions.

[0056] In a further preferred embodiment, the sustained-release membrane has 1 to 5 layers, preferably 1 to 3 layers, such as 1 or 2 layers.

[0057] In a preferred embodiment, the breathable material having micro-nano pores is a polyamide polymer.

[0058] In a further preferred embodiment, the polyamide polymer is at least one selected from aliphatic polyamide polymers, aliphatic-aromatic polyamide polymers and aromatic polyamide polymers.

[0059] In a further preferred embodiment, the polyamide polymer is selected from at least one of polyamide 6, polyamide 11, polyamide 66, and polyamide 1010, or two or more of them are copolymerized or blended and modified.

[0060] In a preferred embodiment, the polymer material that slowly hydrolyzes and / or dissolves under bottom hole conditions is selected from ester-containing polymers and / or hydroxyl-containing polymers.

[0061] In a further preferred embodiment, the ester-containing polymer is selected from at least one or two or more copolymer systems of polybutanediol, polybutylenebutanediol, polypentanediol, polyethylene adipate, polybutylene adipate, polypentane adipate, polyethylene terephthalate, polybutylene terephthalate, polypentane terephthalate, and polyphenyl terephthalate condensation products, preferably from at least one or two or more copolymer or modified systems of polybutanediol, polybutylenebutanediol, polybutylene adipate, polybutylene terephthalate, polybutylene terephthalate, and polypentane terephthalate condensation products; and / or the hydroxyl-containing polymer is selected from at least one of polyvinyl alcohol, reaction-modified polyvinyl alcohol, and blended modified polyethylene.

[0062] In a preferred embodiment, the weight ratio of the foaming surfactant, the solid filler and the adhesive is 1:(0.1-5):(0.001-0.1), preferably 1:(0.5-3):(0.001-0.05).

[0063] For example, the weight ratio of the foaming surfactant and the solid filler is 1:0.5, 1:1, 1:1.5, 1:2, 1:2.5 or 1:3; the weight ratio of the foaming surfactant and the adhesive is 1:0.001, 1:0.005, 1:0.01, 1:0.02, 1:0.03, 1:0.04 or 1:0.05.

[0064] In a further preferred embodiment, the weight ratio of the total weight of the foaming surfactant, the solid filler, and the binder to the sustained-release material is 1:(0.001-0.05), preferably 1:(0.001-0.01).

[0065] For example, the weight ratio of the total weight of the foaming surfactant, solid filler and adhesive to the sustained-release material is 1:0.001, 1:0.002, 1:0.003, 1:0.004, 1:0.005, 1:0.006, 1:0.007, 1:0.008, 1:0.009, 1:0.01, 1:0.02, 1:0.03, 1:0.04 or 1:0.05.

[0066] In a preferred embodiment, the foaming agent is in the shape of a sphere, a rod, a square, or a mixture of one or more thereof, preferably a rod or a sphere, or a mixture of the two.

[0067] In a preferred embodiment, the specific gravity of the foaming agent is 1.0-1.4 g / mL.

[0068] The components in the foaming agent of the present invention have good compatibility and may also contain other treatment agents commonly used in the art.

[0069] The foaming agent containing the gemini anionic surfactant in the present invention contains multiple hydrophilic head groups with positive and negative charges in the system, which can accurately control the electrostatic force between surfactant molecules, so that the foaming agent has both excellent foaming and stabilizing properties and very strong liquid carrying capacity; the number of negatively charged hydrophilic head groups is greater than the number of positively charged hydrophilic head groups, so that the system as a whole is negatively charged, and the adsorption retention in the sandstone gas reservoir is small, which improves the use efficiency of the foaming agent; the critical micelle concentration of the gemini anionic surfactant is often about 1 order of magnitude lower than that of the single-chain surfactant with the same carbon chain. After compounding with the zwitterionic surfactant, due to the electrostatic attraction of the positive and negative ion head groups, the interface efficiency is further improved, so that the critical micelle concentration of the composite foaming agent can be reduced by 1 to 2 orders of magnitude lower than that of the single agent. The low critical micelle concentration can reduce the use concentration of the foaming agent, thereby improving the economy of the foaming agent. In addition, the retention of the amide group in the molecular structure can avoid complex chemical reactions such as hydrogenation reduction, reduce the preparation cost of the foaming agent, and can be applied to other gas wells except ultra-deep wells and deep wells. In addition, the use of membrane coating to achieve the purpose of slow release can minimize the amount of slow release materials used, reducing the damage and pollution that the slow release materials may cause to the bottom of the well. The slow release foaming agent can effectively avoid the problem of the surfactant foaming agent dissolving too quickly in water and the local concentration being too high, prolong the foaming action time, achieve the purpose of continuous liquid carrying, and is applied to drainage and gas production operations.

[0070] The sixth object of the present invention is to provide the use of the gemini anionic surfactant described in the first object of the present invention, the foaming surfactant described in the fourth object of the present invention, or the foaming agent described in the fifth object of the present invention in the gas well foam drainage and gas production industry, especially the use of the foaming surfactant described in the fourth object of the present invention or the foaming agent described in the fifth object of the present invention in the gas well foam drainage and gas production industry, especially the use of the slow-release foaming agent described in the fifth object of the present invention in the gas well foam drainage and gas production industry.

[0071] In a preferred embodiment, gas well foam drainage is carried out as follows: (1) the uncoated foaming surfactant or the slow-release foaming agent is immersed in simulated formation water to obtain a foaming agent solution of a certain concentration; (2) the solution is fully contacted with the gas to form a foam fluid, which carries out the water in the foaming agent solution.

[0072] In a further preferred embodiment, the gas is at least one of nitrogen, methane or natural gas.

[0073] In another preferred embodiment, gas well foam drainage and gas production are carried out as follows: (1) the coated slow-release foaming agent is immersed in simulated formation water for a certain period of time at formation temperature; (2) after the membrane is hydrolyzed, dissolved or infiltrated with water, a foaming agent solution is obtained; (3) after exceeding the minimum foaming concentration, the gas is fully in contact with the foaming agent solution to form a foam fluid, which carries out the water in the foaming agent solution.

[0074] In a further preferred embodiment, the gas is at least one of nitrogen, methane or natural gas.

[0075] In the present invention, when the slow-release foaming agent is used for water drainage and gas recovery, for example but not limited to a specific gas reservoir, the formation temperature is 50-100° C., and the total mineralization of the formation brine is 10,000-200,000 mg / L.

[0076] In the present invention, coated means coated with a sustained-release material, and uncoated means not coated with a sustained-release material.

[0077] The endpoints and any values ​​of the scope disclosed in the present invention are not limited to the precise scope or value, and these scopes or values ​​should be understood to include values ​​close to these scopes or values. For numerical ranges, the endpoint values ​​of each scope, the endpoint values ​​of each scope and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be regarded as specifically disclosed in this article. Hereinafter, in principle, each technical solution can be combined with each other to obtain a new technical solution, which should also be regarded as specifically disclosed in this article.

[0078] Compared with the prior art, the present invention has the following beneficial effects:

[0079] (1) The slow-release foaming agent containing a gemini anionic surfactant in the present invention contains multiple hydrophilic head groups with positive and negative charges in the system, which can accurately control the electrostatic force between surfactant molecules, so that the foaming agent has both excellent foaming and stabilizing properties and very strong liquid carrying capacity; the number of negatively charged hydrophilic head groups is greater than the number of positively charged hydrophilic head groups, so that the system as a whole presents negative charge, and the adsorption retention in the sandstone gas reservoir is small, thereby improving the use efficiency of the foaming agent;

[0080] (2) The critical micelle concentration of gemini anionic surfactants is often about one order of magnitude lower than that of single-chain surfactants with the same carbon chain. After being compounded with zwitterionic surfactants, the interfacial efficiency is further improved due to the electrostatic attraction of the positive and negative ion head groups, making the critical micelle concentration of the composite foaming agent 1 to 2 orders of magnitude lower than that of the single agent. The low critical micelle concentration can reduce the concentration of the foaming agent used, thereby improving the economic efficiency of the foaming agent.

[0081] (3) The retention of the amide group in the molecular structure can avoid complex chemical reactions such as hydrogenation reduction, reduce the preparation cost of the foaming agent, and can be applied to other gas wells except ultra-deep wells and deep wells;

[0082] (4) The use of membrane coating to achieve the purpose of slow release can minimize the amount of slow release materials used, reducing the damage and pollution that the slow release materials may cause to the bottom of the well;

[0083] (5) The slow-release foaming agent can effectively avoid the problem of the surfactant foaming agent dissolving too quickly in water and the local concentration being too high, prolong the foaming action time, achieve the purpose of continuous liquid carrying, and be applied to drainage and gas production operations;

[0084] (6) The technical solution of the present invention can be used for, but not limited to, formation temperatures of 50 to 100°C and formation brine with a total mineralization of 10,000 to 200,000 mg / L. In terms of mass percentage, 0.1 wt% of the foaming agent in 0 to 20,000 mg / L mineralization brine has a foaming height of 165 mm and a liquid carrying rate of 92.7%; after immersion for 72 hours at 65°C, the maximum dissolution percentage is 93.2%; after immersion for 48 hours at 95°C, the maximum dissolution percentage is 99.7%. The slow-release foaming agent containing gemini carboxylates responds to temperature in the formation environment, undergoes precipitation and hydrolysis reactions, and the released foaming agent has excellent foaming and liquid carrying properties, achieving good technical effects. BRIEF DESCRIPTION OF THE DRAWINGS

[0085] Figure 1 The figure is a flow chart of measuring the amount of liquid carried by foam drainage agent. 1 is a constant temperature water bath, 2 is a measuring cup, 3 is circulating water, 4 is a foam collector, 5 is a foaming tube, 6 is a test solution, 7 is a rotor flow meter, and 8 is a gas cylinder.

[0086] Figure 2 The figure is the relationship between the immersion time and the concentration percentage of CSF01-CSF05. The immersion temperature is 95℃, and the percentage refers to the ratio of the concentration of the foam rod measured by ion chromatography to the theoretically calculated concentration of the foaming agent.

[0087] Figure 3 The figure is the relationship between the immersion time and the concentration percentage of CSF01, CSF06~CSF10. The immersion temperature is 95℃, and the percentage refers to the ratio of the concentration of the foam rod measured by ion chromatography to the theoretically calculated concentration of the foaming agent.

[0088] Figure 4 The figure is the relationship between the immersion time and the concentration percentage of CSF01, CSF06~CSF10. The immersion temperature is 65℃, and the percentage refers to the ratio of the concentration of the foam rod measured by ion chromatography to the theoretically calculated concentration of the foaming agent.

[0089] Figure 5 The figure is the relationship between the immersion time and the concentration percentage of CSF11-CSF13. The immersion temperature is 75°C, and the percentage refers to the ratio of the concentration of the foam rod measured by ion chromatography to the theoretically calculated concentration of the foaming agent.

[0090] Figure 6 The figure is the relationship between the immersion time and the concentration percentage of CSF14-CSF16. The immersion temperature is 85°C, and the percentage refers to the ratio of the concentration of the foam rod measured by ion chromatography to the theoretically calculated concentration of the foaming agent. DETAILED DESCRIPTION

[0091] The present invention is described in detail below in conjunction with specific embodiments. It is necessary to point out that the following embodiments are only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made to the present invention by those skilled in the art based on the contents of the present invention still fall within the scope of protection of the present invention.

[0092] It should also be noted that the various specific technical features described in the following specific embodiments can be combined in any suitable manner without contradiction. To avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0093] In addition, the various embodiments of the present invention may be arbitrarily combined as long as they do not violate the concept of the present invention. The technical solutions thus formed belong to part of the original disclosure of this specification and also fall within the protection scope of the present invention.

[0094] The raw materials used in the examples and comparative examples, unless otherwise specified, are disclosed in the prior art, for example, they can be directly purchased or prepared according to the preparation methods disclosed in the prior art.

[0095] The present invention adopts the method of measuring the foaming, foam stabilization and liquid carrying performance of the foam drainage agent to evaluate the foam drainage performance. The specific evaluation method is: firstly, the initial foaming height and the foaming height after a certain period of time of the foam drainage agent are measured by a Ross-Miles method to evaluate the foaming ability and foam stabilization ability of the foam drainage agent. A certain flow rate of gas is continuously introduced into the foam drainage agent solution or the foam drainage agent solution and the oil mixed solution to form foam, and the amount of liquid carried out by the foam after a certain period of time is measured, and the liquid carrying rate is calculated to evaluate the liquid carrying ability of the foam drainage agent.

[0096] [Example 1] Synthesis of Gemini Anionic Surfactant

[0097] 1 -1: Add 74.2 g (1.0 mol) of anhydrous 1,3-propylenediamine and 600 g of 1,4-dioxane to a 2000 ml four-necked flask equipped with a sealed mechanical stirrer, a thermometer, and a condenser, heat to 50°C, slowly dropwise add 215.1 g (2.5 mol) of methyl acrylate at a rate of 1.2 g / min, continue to react for 3 hours after the dropwise addition, remove the unreacted methyl acrylate and the solvent 1,4-dioxane under reduced pressure to obtain methyl propionate of propylenediamine 2 -1, standby. 2 -1, add 450 g of 50% potassium hydroxide solution and 200 g of ethanol to adjust the pH to 13, heat to reflux for 5 hours, and remove the ethanol and methanol produced by the reaction by vacuum distillation. The residue is potassium propylenediamine dipropionate containing excess potassium hydroxide. 3 -1. After adding 300 g of 1,4-dioxane and mixing evenly, lauroyl chloride was added dropwise under vigorous stirring, and the pH was measured to be between 9 and 10. After the addition was completed, the reaction was continued at 60°C for 4 hours to obtain a potassium carboxylate represented by formula (I) 1 -1, the product composition is shown in Table 1.

[0098] 1 -2 Synthesis: Reference 1 -1, except that an equal molar amount of 1,4-butanediamine was used to replace 1,3-propylenediamine. The composition of the obtained product is shown in Table 1.

[0099] 1 -3 Synthesis: Reference 1 -1, except that an equal molar amount of 1,6-hexanediamine is used to replace 1,3-propylenediamine. The composition of the obtained product is shown in Table 1.

[0100] 1 -4 Synthesis: Reference1 -1, except that an equal molar amount of ethylenediamine is used to replace 1,3-propylenediamine, an equal molar amount of hexadecanoyl chloride is used to replace lauroyl chloride, and an equal weight and concentration of sodium hydroxide is used to replace potassium hydroxide. The composition of the obtained product is shown in Table 1.

[0101] 1 -5 Synthesis: Reference 1 -1, except that an equal molar amount of ethylenediamine is used to replace 1,3-propylenediamine, an equal molar amount of octadecanoyl chloride is used to replace lauroyl chloride, and an equal weight and concentration of sodium hydroxide is used to replace potassium hydroxide. The composition of the obtained product is shown in Table 1.

[0102] 1 -6 Synthesis: Reference 1 -1, except that an equal molar amount of ethylenediamine is used to replace 1,3-propylenediamine, an equal molar amount of methyl methacrylate is used to replace methyl acrylate, an equal molar amount of hexadecanoyl chloride is used to replace lauroyl chloride, and an equal weight and concentration of sodium hydroxide is used to replace potassium hydroxide. The composition of the obtained product is shown in Table 1.

[0103] 1 -7 synthesis: add 103.2 g (1.0 mol) of anhydrous diethylenetriamine and 500 g of acetone to a 2000 ml four-necked flask equipped with a sealed mechanical stirrer, a thermometer, and a condenser, slowly drop 176.3 g (2.05 mol) of methyl acrylate at room temperature at a rate of 0.37 g / min, slowly heat to 50°C after dropwise addition, react for 2 hours, remove unreacted raw materials and solvent acetone under reduced pressure, and obtain diethylenetriamine dipropionate methyl ester 2 -7, standby. 7 -1, add 450 g of 50% sodium hydroxide solution and 250 g of ethanol to adjust the pH to 12.5, heat to reflux for 3 hours, and remove the ethanol and methanol produced by the reaction by vacuum distillation. The residue is potassium diethylenetriamine dipropionate containing excess sodium hydroxide. 3 -7. After adding 250 g of acetone and mixing evenly, the temperature was kept at 5°C under vigorous stirring, and octanoyl chloride was added dropwise. The pH value was measured to be about 10. After the addition was completed, the reaction was continued at 40°C for 3 hours. After acidification with hydrochloric acid, ammonia water was added to adjust the system pH to about 11 to obtain the ammonium carboxylate represented by formula (I) 1 -7.

[0104] Table 1

[0105]

[0106]

[0107] [Example 2] Preparation of foaming surfactant

[0108] The gemini anionic surfactant and the zwitterionic surfactant obtained in Example 1 were mixed according to the required ratio to obtain the foaming surfactant F. The structure and composition are shown in Table 2.

[0109]

[0110] [Example 3] Preparation of uncoated foaming agent

[0111] Weigh the foaming surfactant prepared in Example 2, mix it with the solid filler and the binder in the required proportion, and press it into shape. After removing the water, the uncoated foaming agent is obtained. The proportion composition is shown in Table 3. When the product is spherical, the diameter is about 4 cm; when the product is rod-shaped, each stick has a mass of about 1.5 kg, a diameter of 5 cm, a length of 50-60 cm, and a specific gravity of 1.0-1.4 mg / L. In Table 3, the mass ratio of the binder is calculated based on the effective concentration.

[0112] Table 3

[0113]

[0114]

[0115] [Example 4] Preparation of coated foaming agent

[0116] The foaming agent formed by the compression molding of Example 3 is coated with a film (thickness: 30-100 μm) made of a breathable material with micro-nano pores or a polymer material that slowly hydrolyzes or dissolves under bottom-hole conditions, and the foaming agent is obtained by checking that there is no leakage after sealing. The proportion composition is shown in Table 4. In Table 4, the 1# film is a hydrolyzable film, which is copolymerized by terephthalic acid, succinic acid and butanediol in a molar ratio of 1.0:1.0:2; the 2# film is a hydrolyzable film, which is copolymerized by terephthalic acid, oxalic acid and pentanediol in a molar ratio of 2:1.5:0.5; the 3# film is a water-soluble film, which is processed by blending starch and polyvinyl alcohol film PVA17-99; the 4# film is a water-permeable film, which is mixed by PA6 and PA66 in a mass ratio of 9.5 to 0.5, PA6 is polyamide 6, and PA66 is polyamide 66.

[0117] Table 4

[0118]

[0119]

[0120] [Comparative Example 1]

[0121] by 1 -1 and zwitterionic surfactants 4 (R4=C 14 H 29, R5=C2H4OH, R6=C2H4OH, R7=CH2, m=0, n=2, j=1, Y - =COO - ) F13 formed with a molar ratio of 0:1 replaces F01. Take 2000 grams of F13, 1000 grams of sodium tartrate, 500 grams of sodium sulfate, 1000 grams of sodium chloride, add 600 grams of 10% polyethylene glycol as a binder, press and shape to obtain spherical foaming agent SF13, prepare a 0.1wt% foaming agent simulated aqueous solution, and measure the foaming performance and liquid carrying performance in the same way as [Example 3]. The results are shown in Table 5.

[0122] [Comparative Example 2]

[0123] The foaming components in the inventions of CN104342096 and CN103937479 were mixed according to the mass ratio of 20% of the natural compound soapberry essence, 13.3% of fatty alcohol polyoxyethylene ether AEO18 and 6.7% of polylauroyl diethanolamine. 2000 grams of the dried solids were mixed with 1000 grams of sodium tartrate, 500 grams of sodium sulfate and 1000 grams of sodium chloride, and 600 grams of 10% polyethylene glycol were added as a binder. The spherical foaming agent SF14 was obtained by pressing and molding. The 0.1wt% foaming agent simulated aqueous solution was prepared. The foaming performance and liquid carrying performance were measured in the same way as [Experimental Example 1]. The results are shown in Table 5. SF14 was coated with polyvinyl alcohol and acrylic resin films respectively, and the film dissolution and penetration rate was tested in the same way as [Experimental Example 2]. The results showed that after 0.5 hour at 95°C, the percentages (the ratio of the foaming rod concentration measured by ion chromatography to the theoretically calculated foaming agent concentration) were 89.6% and 96.5% respectively. Both films could not play an effective sustained-release role.

[0124] [Experimental Example 1] Foaming and liquid carrying performance test of foaming agent

[0125] (1) The synthesized SF01-SF12 were dissolved in deionized water and simulated saline respectively to prepare a 0.1wt% foaming agent solution, which was added to a Roche foam instrument. The initial foam height and the foam height after 5 minutes were measured by the ROSS-Miles method. The results are shown in Table 5. The salt in the simulated saline was sodium chloride.

[0126] (2) 4000 mL / min of nitrogen was continuously introduced into the aqueous solution of the foaming agent SF01-SF12, and the amount of water carried by the foam within 15 minutes was measured, and the liquid carrying rate was calculated. The results are shown in Table 5. The liquid carrying amount measuring device used is as follows Figure 1 shown.

[0127] Table 5

[0128]

[0129]

[0130] [Experimental Example 2] Membrane dissolution and penetration rate test

[0131] The prepared foaming agent was placed in deionized water and heated to a certain temperature. The chloride ion concentration in the solid filler was determined by ion chromatography and converted to the foaming agent concentration. The concentration was compared with the theoretically calculated foaming agent concentration after complete dissolution. The results are shown in Table 1. Figure 2 to Figure 6 As shown. At 95°C, the polyvinyl alcohol film (3# film) has released 88.4% of the foaming agent in 0.5 hours and completely dissolved in 4 hours; 1#, 2# and 4# films can play a certain sustained release role. With the extension of immersion time, the concentration of the foaming agent in the solution gradually increases; the more film layers, the lower the concentration of the foaming agent in the solution at the same time. The properties and stability of the membrane are the main factors that determine the sustained release. Controlling the appropriate membrane hydrolysis, dissolution and water seepage rate is conducive to the slow release of the effective ingredients of the foaming agent, ensuring that the foaming agent fully exerts its drainage and gas collection effects.

[0132] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.

Claims

1. A foaming surfactant, comprising a gemini anionic surfactant and a zwitterionic surfactant, wherein the gemini anionic surfactant is selected from at least one of the compounds represented by formula (I): In formula (I), R1 is selected from C7 to C 41 Hydrocarbon or C7~C 41 The repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C8 hydrocarbon group or a C1-C8 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from C1-C 15 a is any integer from 0 to 8; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C6 alkylene groups, and repeated R6 are the same or different; M is hydrogen, a metal ion or a cationic group; The zwitterionic surfactant is selected from at least one of the compounds represented by formula (II): R4' is selected from C4~C 32 Hydrocarbon or C4~C 32 R5' and R6' are each independently selected from (CH2) c OH, (CH2) d CH3 or C6H5CH2, c=any integer in the range of 2 to 4, d=any integer in the range of 0 to 5; R7' is selected from C1 to C5 alkylene groups or C1 to C5 substituted alkylene groups; m is the number of propoxy groups added, m=0 to 10; n is the number of ethoxy groups added, n=0 to 20; j=0 or 1; Y - Selected from COO - 、SO3 - or OSO3 - .

2. The foaming surfactant according to claim 1, characterized in that In formula (I), R1 is selected from C7 to C 31 Hydrocarbon or C7~C 31 The repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C5 hydrocarbon group or a C1-C5 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from C2-C 10 a is any integer from 0 to 6; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C4 alkylene groups, and repeated R6 are the same or different; M is hydrogen, a metal ion or a cationic group.

3. The foaming surfactant according to claim 1, characterized in that In formula (I), R1 is selected from C7 to C 21 Hydrocarbon or C7~C 21 wherein the repeated R1 is the same or different; R2 and R3 are each independently selected from hydrogen, a C1-C3 hydrocarbon group or a C1-C3 substituted hydrocarbon group, and the repeated R2 or R3 are the same or different; R4 and R5 are each independently selected from a C2-C6 straight-chain alkylene group or a branched alkylene group; a is any integer from 0 to 3; R6 is selected from -COO - 、-SO3 - 、OSO3 - 、-R7COO - 、-R7SO3 - or -R7OSO3 - , R7 is selected from C1-C2 alkylene groups, and repeated R6 are the same or different; M is hydrogen, an alkali metal ion or a formula NR8(R9)(R 10 )(R 11 ) shown in the group, R8, R9, R 10 , R 11 Each is independently selected from hydrogen, a hydrocarbon group or a substituted hydrocarbon group.

4. The foaming surfactant according to claim 1, wherein the preparation method of the anionic surfactant comprises: (1) Utilize H2N[R4NH] a R5NH2 reacts with CH(R2)=C(R3)R6R0 to obtain the aminocarboxylate intermediate R0R6CH(R3)CH(R2)HN[R4NH] a R5NHCH(R2)CH(R3)R6R0, wherein R0 is selected from a hydrocarbon group or a substituted hydrocarbon group; (2) subjecting the aminocarboxylate to saponification to obtain an amino salt MR6CH(R3)CH(R2)HN[R4NH] a R5NHCH(R2)CH(R3)R6M, wherein M has the same definition as in formula (I); (3) reacting the amine salt with R1COX to obtain a compound represented by formula (I), wherein X is selected from a halogen element and R1 has the same definition as that of formula (I).

5. The foaming surfactant according to claim 4, characterized in that In step (1), firstly H2N[R4NH] a R5NH2 and a solvent are mixed, and CH(R2)=C(R3)R6R0 is added dropwise thereto for reaction. After the reaction is completed, unreacted raw materials and solvent are removed to obtain an aminocarboxylate intermediate; and / or, In step (1), H2N[R4NH] a The molar ratio of R5NH2 to CH(R2)=C(R3)R6R0 is 1:(1-6); and / or, In step (1), the solvent is selected from an organic solvent; and / or, In step (1), the reaction temperature is 30 to 100° C.; and / or the reaction time is 1 to 8 hours; and / or unreacted raw materials and solvents are removed by reduced pressure.

6. The foaming surfactant according to claim 4, characterized in that In step (1), H2N[R4NH] a The molar ratio of R5NH2 to CH(R2)=C(R3)R6R0 is 1:(2-4); and / or, In step (1), the solvent is selected from at least one of acetone, diethyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, and propylene glycol diethyl ether; and / or, In step (1), the reaction temperature is 40 to 90°C 7. The foaming surfactant according to claim 4, characterized in that In step (2), the saponification treatment is carried out in an alkaline solution containing alcohol, and the amine salt is obtained by filtration.

8. The foaming surfactant according to claim 7, characterized in that The alcohol is selected from at least one of methanol, ethanol, isopropanol and propanol.

9. The foaming surfactant according to claim 7, characterized in that The pH value of the alkaline solution is 11-14; and / or the saponification treatment is performed under heating reflux.

10. The foaming surfactant according to claim 7, characterized in that The pH value of the alkaline solution is 12-13.

11. The foaming surfactant according to any one of claims 4 to 10, characterized in that: In step (3), the amine salt is mixed with a solvent, the pH is adjusted to 8 to 11, and then R1COX is added dropwise to react; and / or, In step (3), the molar ratio of the amine salt to R1COX is (0.9-1.3):1; and / or, In step (3), the solvent is selected from at least one of acetone, ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, and propylene glycol diethyl ether; and / or, In step (3), the reaction temperature is -10 to 80°C and the reaction time is 2h to 10h.

12. The foaming surfactant according to claim 11, characterized in that In step (3), the amine salt is mixed with a solvent and the pH is adjusted to 9 to 10; and / or, In step (3), the molar ratio of the amine salt to R1COX is (0.95-1.05):

1.

13. The foaming surfactant according to claim 1, characterized in that The molar ratio of the gemini surfactant to the zwitterionic surfactant is 1:(0.1-10).

14. The foaming surfactant according to claim 1, characterized in that The molar ratio of the gemini surfactant to the zwitterionic surfactant is 1:(0.2-5).

15. A foaming agent, comprising the foaming surfactant according to any one of claims 1 to 14, a solid filler, an adhesive and an optional sustained-release material; the solid filler is selected from at least one of carboxylates, carbonates, bicarbonates, sulfates, bisulfates, phosphates, borates and metal halides; the adhesive is at least one of polyacrylamide, guar gum, cellulose, starch and polyethylene glycol; the sustained-release material is a membrane, which is a membrane formed by a breathable material with micro-nano pores, or a membrane formed by a polymer material that slowly hydrolyzes and / or dissolves under bottom hole conditions.

16. The foaming agent according to claim 15, characterized in that: The solid filler is selected from at least one of formates, acetates, tartaric acid and salts, citric acid and salts, phthalic acid and salts, gallic acid and salts, carbonates, bicarbonates, sulfates, phosphates, borates, metal halides, urea, and biuret; and / or, The adhesive is selected from at least one of dextrin, epoxy resin, polyacrylamide, starch, cellulose, and polyethylene glycol; and / or, The sustained-release membrane has 1 to 5 layers.

17. The foaming agent according to claim 15, characterized in that: The breathable material with micro-nano pores is a polyamide polymer; and / or, The polymer material which slowly hydrolyzes and / or dissolves under bottom hole conditions is selected from polymers containing ester groups and / or polymers containing hydroxyl groups.

18. The foaming agent according to claim 17, characterized in that: The breathable material having micro-nano pores is selected from at least one of aliphatic polyamide polymers, aliphatic-aromatic polyamide polymers and aromatic polyamide polymers; and / or, The ester-containing polymer is selected from at least one of polyethylene butanedicarboxylate, polybutylene butanedicarboxylate, polypentane butanedicarboxylate, polyethylene adipate, polybutylene adipate, polypentane adipate, polyethylene terephthalate, polybutylene terephthalate, polypentane terephthalate, and polyphenyl terephthalate condensation products, or a copolymer system of two or more thereof; and / or, the hydroxyl-containing polymer is selected from at least one of polyvinyl alcohol, reaction-modified polyvinyl alcohol, and blended modified polyethylene.

19. The foaming agent according to claim 17, characterized in that: The ester-containing polymer is selected from at least one of poly(ethylene butadiene phthalate), poly(butylene butadiene phthalate), poly(ethylene adipate), poly(butylene adipate), poly(ethylene terephthalate), poly(butylene terephthalate), and poly(pentylene terephthalate) condensation products, or a copolymer or modified system of two or more thereof.

20. The foaming agent according to any one of claims 15 to 19, characterized in that: The weight ratio of the foaming surfactant, the solid filler, the binder and the sustained-release material is 1:(0.1-5):(0.001-0.1); and / or, The weight ratio of the total weight of the foaming surfactant, the solid filler and the adhesive to the sustained-release material is 1:(0.001-0.05).

21. The foaming agent according to claim 20, characterized in that The weight ratio of the foaming surfactant, the solid filler, the binder and the sustained-release material is 1:(0.5-3):(0.001-0.05); and / or, The weight ratio of the total weight of the foaming surfactant, the solid filler and the adhesive to the sustained-release material is 1:(0.001-0.01).

22. Use of the foaming surfactant according to any one of claims 1 to 14 or the foaming agent according to any one of claims 15 to 21 in the gas well foam drainage gas production industry.

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