Stearamide bis (hydroxysulfobetaine) composite foam scrubbing agent for low-permeability gas well as well as preparation method and application of stearamide bis (hydroxysulfobetaine) composite foam scrubbing agent

Abstract

The invention discloses a stearamide bis (hydroxysulfobetaine) composite foam scrubbing agent for a low-permeability gas well and a preparation method and application thereof, and belongs to the technical field of foam scrubbing agent preparation.The stearamide bis (hydroxysulfobetaine) composite foam scrubbing agent is prepared by mixing stearamide bis (hydroxysulfobetaine), amine oxide, triethanolamine and water, heating the mixture to 30-50 DEG C and stirring the mixture to obtain a reactant A; mixing a fluorocarbon surfactant, methanol, alpha-alkenyl sulfonate and water, heating to 70-80 DEG C, and stirring to obtain a reactant B; and finally, adding the reactant A into the reaction kettle, heating to 30-40 DEG C, adding 80% of the auxiliary agent, quickly stirring for 5-10 minutes, heating to 40-50 DEG C, adding the reactant B, slowly stirring for 5-10 minutes, heating to 50-60 DEG C, adding the rest 20% of the auxiliary agent, quickly stirring for 5-10 minutes, heating to 70-80 DEG C, slowly stirring, and cooling to obtain the foam scrubbing agent. The foam scrubbing agent prepared by the invention can be used in a high-salinity environment, and the problems of corrosion, blockage and the like caused by too high salinity are avoided.

Description

Technical Field

[0001] The invention belongs to the technical field of foaming agent preparation, and relates to a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, and a preparation method and application thereof. Background Art

[0002] Low permeability gas fields refer to oil and gas reservoirs with low underground reservoir porosity and permeability less than 0.1mD under geological conditions, with great difficulty in oil and gas exploration and development and low recovery rate. Low permeability gas fields are of great significance in my country's oil and gas development. Among the proven reserves, the proportion of low permeability oil reservoirs is very high, accounting for more than 2 / 3 of the national reserves, and the development potential is huge. Foam drainage is to introduce some foam drainage agents into the gas field, so that a large amount of low-density water-containing foam is generated during the vertical flow of gas-liquid two-phase mixing. The foam carries water to the ground with the air flow, improving the vertical liquid lifting capacity of gas and liquid, and achieving the purpose of drainage and gas recovery.

[0003] Foaming agent is a chemical agent used to increase the recovery rate of oil reservoirs. It is mainly composed of surfactants, additives, anti-seepage agents and other components. It can form foam at the oil-water interface and has good emulsification and dispersion effects. Foaming agent can increase the recovery rate and reduce the cost of gas well development. The use of foaming agent can increase production without increasing too much engineering investment, reduce development costs and reduce the risk of environmental pollution.

[0004] When the temperature and mineralization of the gas field increase, the foaming ability and stability of the foaming agent are greatly reduced, and the effect of drainage and gas recovery is often not achieved. Therefore, it is urgent to design a salt-resistant foaming agent for low permeability gas fields. Summary of the invention

[0005] The purpose of the present invention is to solve the technical problem that the foaming agent in the prior art is easily corroded and blocked due to high salinity in a high mineralization environment, thereby affecting the gas field production efficiency, and to provide a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, and a preparation method and application thereof.

[0006] In order to achieve the above object, the present invention adopts the following technical solutions:

[0007] In a first aspect, the present invention provides a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells. The components thereof include, by mass percentage, 30% to 40% of stearamide bishydroxysulfobetaine, 25% to 40% of amine oxide, 8% to 18% of α-olefin sulfonate, 5% to 8% of triethanolamine, 0.5% to 3% of fluorocarbon surfactant, 0.5% to 3.5% of methanol, 0.5% to 1.5% of auxiliary agent, and the balance being water.

[0008] Furthermore, the auxiliary agent comprises, by mass percentage, 40% to 60% sodium dodecylbenzene sulfonate, 0.2% to 1.5% sodium lauroamphoacetate, and the remainder is coconut oil fatty acid diethanolamide.

[0009] Furthermore, the fluorocarbon surfactant is perfluorododecyl carboxylate.

[0010] Furthermore, the α-olefin sulfonate is C 14 -C 18 Sodium olefin sulfonate or C 14 -C 18 One or a mixture of two of potassium olefin sulfonates.

[0011] In a second aspect, the present invention provides a method for preparing the stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, comprising the following steps:

[0012] S1, mixing stearamide bishydroxysulfobetaine, amine oxide, triethanolamine and water, heating to 30° C. to 50° C. and stirring to obtain a reactant A;

[0013] S2, mixing a fluorocarbon surfactant, methanol, α-olefin sulfonate and water, heating to 70° C. to 80° C. and stirring to obtain a reactant B;

[0014] S3, add reactant A into the reactor and heat it to 30℃~40℃, add 80% of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 40℃~50℃, add reactant B and stir slowly for 5min~10min, then raise the temperature to 50℃~60℃, add the remaining 20% ​​of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 70℃~80℃ and stir slowly, and obtain the foaming agent after cooling.

[0015] Furthermore, the preparation process of stearamide bishydroxysulfobetaine in S1 comprises the following steps:

[0016] S101, at 40°C, N,N-dimethyl-1,3-propylenediamine was added dropwise to oleic acid, and then the temperature was raised to 155°C. Under nitrogen protection, the reaction was carried out for 5h to 8h to obtain N,N-dimethyl-N′-oleic acid acyl propylamine;

[0017] S102, mixing N,N-dimethyl-N′-oleyl propylamine with an ethanol aqueous solution, adding sodium 3-chloro-2-hydroxypropanesulfonate dropwise, adjusting the pH to 8 under nitrogen protection, stirring and reacting at 85° C. for 7 h to 9 h to obtain crude oleamidopropyl hydroxysulfobetaine, and then removing impurities by reduced pressure distillation to obtain pure oleamidopropyl hydroxysulfobetaine;

[0018] S103, reacting pure oleic acid amidopropyl hydroxysulfobetaine with hydrogen bromide to generate 10-bromo-octadecylamidopropyl hydroxysulfobetaine, then mixing 10-bromo-octadecylamidopropyl hydroxysulfobetaine with an isopropanol solution of dimethylamine, passing nitrogen gas for protection, slowly heating to 165° C., reacting at a constant temperature for 8 h to 10 h, cooling to room temperature, distilling out the unreacted isopropanol solution of dimethylamine, then adding hydrochloric acid for pickling, collecting the lower layer of alkyldimethylamine hydrochloride aqueous solution, then adding sodium hydroxide solution to neutralize to neutrality, separating the oil phase, drying and filtering to obtain N,N-dimethyl-amino-octadecylamidopropyl hydroxysulfobetaine;

[0019] S104, sodium 3-chloro-2-hydroxypropanesulfonate is added dropwise to N,N-dimethyl-amino-octadecylamidopropylhydroxysulfobetaine, and the pH is adjusted to 8 under nitrogen protection. The reaction is stirred at 90° C. for 9 h to 10 h to obtain crude stearamide bishydroxysulfobetaine, and then impurities are removed by reduced pressure distillation to obtain pure stearamide bishydroxysulfobetaine.

[0020] Furthermore, the molar ratio of oleic acid to N,N-dimethyl-1,3-propylenediamine in S101 is 1:1; the volume ratio of ethanol to water in the ethanol aqueous solution in S102 is 15:85; and the molar ratio of N,N-dimethyl-N′-oleic acid acyl propylamine to sodium 3-chloro-2-hydroxypropanesulfonate is 8:10.

[0021] Furthermore, in the S103, the molar ratio of 10-bromo-octadecylamidopropyl hydroxysulfobetaine to dimethylamine is 1-3:1; the volume concentration of the isopropanol solution of dimethylamine is 25%; the concentration of hydrochloric acid is 0.5 mol / L; and the mass concentration of the sodium hydroxide solution is 20%.

[0022] Furthermore, the rapid stirring rate in S3 is 120 r / min to 150 r / min, and the slow stirring rate is 60 r / min to 80 r / min.

[0023] In a third aspect, the present invention provides a use of a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells in the exploitation of low permeability gas fields.

[0024] Compared with the prior art, the present invention has the following beneficial effects:

[0025] The present invention discloses a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, and a preparation method and application thereof, which solves the problem of high mineralization, ensures continuous and stable production of gas wells, improves the well opening rate, and also solves the problem of drainage and gas production in methanol injection gas wells. The salt-resistant foaming agent of the present invention can be used in a high-salinity environment to avoid corrosion and blockage problems caused by high salt content, can effectively clean blockages inside oil wells or pipelines, improve the efficiency of oil field exploitation, and help reduce corrosion of steel pipes and equipment. The betaine surfactant is mixed with alpha-olefin sulfonate to enhance the salt resistance and temperature resistance of the foaming agent. The foaming agent prepared by the method of the present invention has good salt resistance and thermal stability, high anti-mineralization degree, good temperature and salt resistance, and good foaming performance and foam stabilizing performance. Reactant A and reactant B are first prepared separately, and then the auxiliary agent is added to the reactant A and the mixed solution of reactant A and reactant B in batches to further improve the salt resistance, foaming performance and foam stabilizing performance of the foaming agent. Different substances are added in different temperature ranges to make the prepared foaming agent have better performance.

[0026] Furthermore, the stearamide bishydroxysulfobetaine prepared by the present invention has a strong liquid carrying capacity in a high mineralization and high condensate oil environment, can increase the foam liquid film viscosity of the foaming agent and improve the foam performance, and the addition of ammonium salt can improve the foaming ability and liquid carrying capacity of stearamide bishydroxysulfobetaine. In a high-salt environment, it can neutralize the charge of anionic surfactants and reduce their interaction with anionic salts, thereby improving their foam stability and salt resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0028] Figure 1 is a flow chart of the preparation method of the present invention;

[0029] Figure 2 The present invention is a preparation flow chart of stearamide bishydroxysulfobetaine. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] In the present invention, unless otherwise specified, all the embodiments and preferred implementation methods mentioned herein can be combined with each other to form a new technical solution.

[0032] In the present invention, unless otherwise specified, all technical features and preferred features mentioned herein can be combined with each other to form a new technical solution.

[0033] In the present invention, unless otherwise specified, percentage (%) or part refers to the weight percentage or weight part relative to the composition.

[0034] In the present invention, unless otherwise specified, the components or preferred components involved can be combined with each other to form a new technical solution.

[0035] In the present invention, unless otherwise specified, the numerical range "a-b" represents an abbreviation of any real number combination between a and b, where a and b are real numbers. For example, the numerical range "6-22" means that all real numbers between "6-22" have been listed in this document, and "6-22" is just an abbreviation of these numerical combinations.

[0036] The “range” disclosed in the present invention is in the form of a lower limit and an upper limit, which can be one or more lower limits, and one or more upper limits, respectively.

[0037] In the present invention, the term "and / or" used herein refers to any combination and all possible combinations of one or more of the associated listed items, and includes these combinations.

[0038] In the present invention, unless otherwise specified, each reaction or operation step can be carried out sequentially or in accordance with the sequence. Preferably, the reaction method herein is carried out sequentially.

[0039] Unless otherwise specified, the professional and scientific terms used herein have the same meanings as those familiar to those skilled in the art. In addition, any method or material similar or equivalent to the described content may also be applied to the present invention.

[0040] The present invention is further described in detail below in conjunction with the accompanying drawings:

[0041] See also Figure 1 The invention discloses a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells. The components thereof include, by mass percentage, 30% to 40% of stearamide bishydroxysulfobetaine, 25% to 40% of amine oxide, 8% to 18% of α-olefin sulfonate, 5% to 8% of triethanolamine, 0.5% to 3% of fluorocarbon surfactant, 0.5% to 3.5% of methanol, 0.5% to 1.5% of auxiliary agent, and the balance is water.

[0042] The foaming agent of the present invention solves the problem of high mineralization, ensures continuous and stable production of gas wells, improves the opening rate of wells, and also solves the problem of drainage and gas production of methanol injection gas wells. The salt-resistant foaming agent prepared by using the above raw materials can be used in a high-salinity environment, avoids corrosion and blockage problems caused by high salt content, can effectively clean blockages inside oil wells or pipelines, improves the efficiency of oil field exploitation, and helps to reduce corrosion of steel pipes and equipment. The betaine surfactant is mixed with α-olefin sulfonate to enhance the salt resistance and temperature resistance of the foaming agent. Triethanolamine can improve the stability of the foam, effectively reduce the situation of foam rupture, and at the same time, it can also play the role of a dispersant and corrosion inhibitor. α-olefin sulfonate can reduce the formation pressure to facilitate the flow of oil, and can also enhance the stability of the foam, thereby improving the effect of the foaming agent, and also has the effect of inhibiting sediments and inhibiting corrosion and rust. The fluorocarbon surfactant can increase the foaming performance and liquid carrying performance of the foaming agent, and by adding an auxiliary agent, the salt resistance and foam stability of the foaming agent can be further improved.

[0043] In a feasible embodiment of the present invention, the auxiliary agent is measured by mass percentage, and its components include 40% to 60% sodium dodecylbenzene sulfonate, 0.2% to 1.5% sodium lauroamphoacetate, and the remainder is coconut oil fatty acid diethanolamide. Sodium dodecylbenzene sulfonate can reduce the surface tension of the liquid, make the liquid easier to form foam, and increase the stability of the foam. Sodium lauroamphoacetate can improve the stability and cleaning effect of the foam, and also has antibacterial properties. The complex formed by sodium dodecylbenzene sulfonate and sodium lauroamphoacetate can increase the salt resistance of the foaming agent, because this complex can enhance the stability of the foam, so that it can still maintain good foam performance in a high-salt environment. Adding coconut oil fatty acid diethanolamide can enhance the solubility and stability of the foaming agent, improve its hydrophobicity and surface activity, enhance its cleaning effect and emulsification performance, and also increase the richness and stability of the foam.

[0044] In a feasible embodiment of the present invention, the fluorocarbon surfactant is perfluorododecyl carboxylate. Fluorocarbon surfactant has high surface activity, high thermodynamic and chemical stability, and perfluorododecyl carboxylate (PFDoA) can enhance the stability and oil resistance of foam, and improve the cleaning effect and service life of the foaming agent.

[0045] In a feasible embodiment of the present invention, the α-olefin sulfonate is C 14 -C 18 Sodium olefin sulfonate or C 14 -C 18One or a mixture of two of potassium olefin sulfonate. Sodium C14-C18 olefin sulfonate and potassium C14-C18 olefin sulfonate are both non-ionic surfactants with good surface activity and emulsification properties, good cleaning effect, good grease emulsification, can effectively remove oil and stains, and can improve the foam stability of the foaming agent.

[0046] The embodiment of the present invention provides a method for preparing a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, comprising the following steps:

[0047] S1, mixing stearamide bishydroxysulfobetaine, amine oxide, triethanolamine and water, heating to 30° C. to 50° C. and stirring to obtain a reactant A;

[0048] S2, mixing a fluorocarbon surfactant, methanol, α-olefin sulfonate and water, heating to 70° C. to 80° C. and stirring to obtain a reactant B;

[0049] S3, add reactant A into the reactor and heat it to 30℃~40℃, add 80% of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 40℃~50℃, add reactant B and stir slowly for 5min~10min, then raise the temperature to 50℃~60℃, add the remaining 20% ​​of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 70℃~80℃ and stir slowly, and obtain the foaming agent after cooling.

[0050] The foaming agent prepared by the above method has good salt resistance and thermal stability, high resistance to mineralization, good temperature and salt resistance, and good foaming performance and foam stabilizing performance. Reactant A and reactant B are first prepared separately, and then the auxiliary agent is added to reactant A and the mixed solution of reactant A and reactant B in batches to further improve the salt resistance, foaming performance and foam stabilizing performance of the foaming agent. Different substances are added in different temperature ranges to make the prepared foaming agent have better performance.

[0051] See also Figure 2 In a feasible embodiment of the present invention, the preparation process of stearamide bishydroxysulfobetaine in S1 comprises the following steps:

[0052] S101, at 40°C, N,N-dimethyl-1,3-propylenediamine was added dropwise to oleic acid, and then the temperature was raised to 155°C. Under nitrogen protection, the reaction was carried out for 5h to 8h to obtain N,N-dimethyl-N′-oleic acid acyl propylamine;

[0053] S102, mixing N,N-dimethyl-N′-oleyl propylamine with an ethanol aqueous solution, adding sodium 3-chloro-2-hydroxypropanesulfonate dropwise, adjusting the pH to 8 under nitrogen protection, stirring and reacting at 85° C. for 7 h to 9 h to obtain crude oleamidopropyl hydroxysulfobetaine, and then removing impurities by reduced pressure distillation to obtain pure oleamidopropyl hydroxysulfobetaine;

[0054] S103, reacting pure oleic acid amidopropyl hydroxysulfobetaine with hydrogen bromide to generate 10-bromo-octadecylamidopropyl hydroxysulfobetaine, then mixing 10-bromo-octadecylamidopropyl hydroxysulfobetaine with an isopropanol solution of dimethylamine, passing nitrogen gas for protection, slowly heating to 165° C., reacting at a constant temperature for 8 h to 10 h, cooling to room temperature, distilling out the unreacted isopropanol solution of dimethylamine, then adding hydrochloric acid for pickling, collecting the lower layer of alkyldimethylamine hydrochloride aqueous solution, then adding sodium hydroxide solution to neutralize to neutrality, separating the oil phase, drying and filtering to obtain N,N-dimethyl-amino-octadecylamidopropyl hydroxysulfobetaine;

[0055] S104, sodium 3-chloro-2-hydroxypropanesulfonate is added dropwise to N,N-dimethyl-amino-octadecylamidopropylhydroxysulfobetaine, and the pH is adjusted to 8 under nitrogen protection. The reaction is stirred at 90° C. for 9 h to 10 h to obtain crude stearamide bishydroxysulfobetaine, and then impurities are removed by reduced pressure distillation to obtain pure stearamide bishydroxysulfobetaine.

[0056] The stearamide bishydroxysulfobetaine prepared by the above method has a strong liquid carrying capacity in a high mineralization and high condensate oil environment, can increase the foam liquid film viscosity of the foaming agent and improve the foam performance. The bishydroxysulfonyl group can improve the foaming ability and liquid carrying capacity of the stearamide bishydroxysulfobetaine. In a high salt environment, it can neutralize the charge of the anionic surfactant and reduce its interaction with the anionic salt, thereby improving its foam stability and salt resistance.

[0057] In a feasible embodiment of the present invention, the molar ratio of oleic acid to N,N-dimethyl-1,3-propylenediamine in S101 is 1:1; the volume ratio of ethanol to water in the ethanol aqueous solution in S102 is 15:85; and the molar ratio of N,N-dimethyl-N′-oleic acid acyl propylamine to sodium 3-chloro-2-hydroxypropanesulfonate is 8:10.

[0058] In a feasible embodiment of the present invention, the molar ratio of 10-bromo-octadecylamidopropyl hydroxysulfobetaine to dimethylamine in S103 is 1-3:1; the volume concentration of the isopropanol solution of dimethylamine is 25%; the concentration of hydrochloric acid is 0.5 mol / L; and the mass concentration of the sodium hydroxide solution is 20%.

[0059] In a feasible embodiment of the present invention, the rapid stirring rate in S3 is 120r / min to 150r / min, and the slow stirring rate is 60r / min to 80r / min. Rapid stirring allows the auxiliary agent and reactants A and B to be fully mixed, and slow stirring allows the mixed solution of reactants A and auxiliary agent to be slowly mixed with reactant B, so that the prepared foaming agent has better foaming performance and foam stabilization performance.

[0060] The stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to the embodiment of the present invention can be applied to the exploitation of low permeability gas fields.

[0061] Embodiment 1:

[0062] A stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells, wherein the raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 40% of amine oxide, 9% of sodium C14-C18 olefin sulfonate, 5.5% of triethanolamine, 1% of perfluorododecyl carboxylate, 2% of methanol, 1% of an auxiliary agent, and the balance is water;

[0063] The auxiliary agent comprises 48% sodium dodecylbenzene sulfonate and 1% sodium lauroamphoacetate by weight, and the balance is coconut oil fatty acid diethanolamide;

[0064] The preparation method of the stearamide bishydroxysulfobetaine is as follows:

[0065] S101, add a certain amount of oleic acid into a three-necked flask, pass nitrogen to expel the air, and at 40°C, add a certain amount of N,N-dimethyl-1,3-propylenediamine dropwise, the molar ratio of oleic acid to N,N-dimethyl-1,3-propylenediamine is 1:1, then heat to 155°C, react for 8 hours under nitrogen protection, and obtain N,N-dimethyl-N′-oleic acid acyl propylamine.

[0066] S102, the N,N-dimethyl-N′-oleic acid acyl propylamine prepared above is mixed with a mixed solvent ethanol aqueous solution, wherein the volume ratio of ethanol to water in the ethanol aqueous solution is 15:85, and 3-chloro-2-hydroxypropane sulfonate is added dropwise in a molar ratio of N,N-dimethyl-N′-oleic acid acyl propylamine to sodium 3-chloro-2-hydroxypropane sulfonate of 8:10, and under nitrogen protection, the pH is adjusted to 8, and the reaction is stirred at 85° C. for 9 hours to obtain crude oleic acid amidopropyl hydroxysulfonate, and the above betaine is then distilled under reduced pressure to remove isopropanol, and then dissolved and filtered with hot isopropanol solvent to remove impurities, and finally the isopropanol solvent is taken out by distillation under reduced pressure to obtain relatively pure oleic acid amidopropyl hydroxysulfonate.

[0067] S103, the above oleic acid amidopropyl hydroxysulfonyl betaine is subjected to an addition reaction with hydrogen bromide to generate 10-bromo-octadecylamidopropyl hydroxysulfonyl betaine, the molar ratio of 10-bromo-octadecylamidopropyl hydroxysulfonyl betaine to dimethylamine is 3:1, the concentration of the isopropanol solution of dimethylamine is 25%, nitrogen is passed through for protection, the temperature is first slowly raised to 165° C., the reaction is carried out at a constant temperature for 8 hours, and after cooling to room temperature, the unreacted dimethylamine isopropanol solution is distilled out. After the distillation is completed, 0.5 mol / L hydrochloric acid is added for pickling, the lower layer of alkyl dimethylamine hydrochloride aqueous solution is collected, 20% sodium hydroxide solution is added to neutralize to neutrality, the oil phase is separated, and dried and filtered to obtain N,N-dimethyl-amino-octadecylamidopropyl hydroxysulfonyl betaine.

[0068] S104, the molar ratio of N, N-dimethyl-amino-octadecylamidopropyl hydroxysulfobetaine to sodium 3-chloro-2-hydroxypropanesulfonate is 2:3, 3-chloro-2-hydroxypropanesulfonate is added dropwise, the pH is adjusted to 8 under nitrogen protection, and the reaction is stirred at 90° C. for 10 hours to obtain crude stearamide bishydroxysulfobetaine, and the above betaine is then distilled under reduced pressure to remove isopropanol, and then dissolved and filtered with hot isopropanol solvent to remove impurities, and finally the isopropanol solvent is distilled under reduced pressure to obtain relatively pure stearamide bishydroxysulfobetaine.

[0069] The preparation method of the above-mentioned bubble extrusion comprises the following steps:

[0070] First, prepare stearamide bishydroxysulfobetaine according to S101 to S104, and then weigh stearamide bishydroxysulfobetaine, amine oxide, sodium C14-C18 olefin sulfonate, triethanolamine, perfluorododecyl carboxylate, methanol, auxiliary agent and water according to the formula for later use;

[0071] Add weighed stearylamide bishydroxysulfobetaine, amine oxide, triethanolamine and 50% water into a reaction kettle, heat to 30-50° C. and stir to obtain reactant A;

[0072] Add the weighed fluorocarbon surfactant, methanol, α-olefin sulfonate and 50% water into a reaction kettle, heat to 70-80° C. and stir to obtain reactant B;

[0073] Add reactant A to the reactor and heat it to 35°C, start adding 80% of the auxiliary agent and stir rapidly for 8 minutes, raise the temperature to 45°C, add reactant B and start slow stirring for 8 minutes, raise the temperature to 55°C, add the remaining 20% ​​of the auxiliary agent and stir rapidly for 8 minutes, raise the temperature to 75°C and stir slowly, and obtain the foaming agent after cooling; the rapid stirring rate is 135r / min, and the slow stirring rate is 70r / min.

[0074] Embodiment 2:

[0075] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 30% of amine oxide, 12% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 1% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water;

[0076] The auxiliary agent comprises 48% sodium dodecylbenzene sulfonate and 1% sodium lauroamphoacetate by weight, and the remainder is coconut oil fatty acid diethanolamide.

[0077] Embodiment 3:

[0078] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 35% of stearylamide bishydroxysulfobetaine, 30% of amine oxide, 15% of sodium C14-C18 olefin sulfonate, 5% of triethanolamine, 2% of perfluorododecyl carboxylate, 0.5% of methanol, 0.5% of auxiliary agent, and the balance is water.

[0079] The auxiliary agent comprises 48% sodium dodecylbenzene sulfonate and 1% sodium lauroamphoacetate by weight, and the remainder is coconut oil fatty acid diethanolamide.

[0080] Embodiment 4:

[0081] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 35% of stearylamide bishydroxysulfobetaine, 25% of amine oxide, 15% of α-olefin sulfonate, 8% of triethanolamine, 3% of fluorocarbon surfactant, 3.5% of methanol, 1.5% of auxiliary agent, and the balance is water.

[0082] The auxiliary agent comprises 48% sodium dodecylbenzene sulfonate and 1% sodium lauroamphoacetate by weight, and the remainder is coconut oil fatty acid diethanolamide.

[0083] Embodiment 5:

[0084] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 25% of amine oxide, 15% of sodium C14-C18 olefin sulfonate, 6.5% of triethanolamine, 2% of perfluorododecyl carboxylate, 3% of methanol, 1% of auxiliary agent, and the balance is water;

[0085] The auxiliary agent comprises 40% sodium dodecylbenzene sulfonate and 0.2% sodium lauroamphoacetate by weight, and the balance is coconut oil fatty acid diethanolamide.

[0086] Embodiment 6:

[0087] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 30% of stearamide bishydroxysulfobetaine, 35% of amine oxide, 18% of sodium C14-C18 olefin sulfonate, 6.5% of triethanolamine, 3% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water;

[0088] The auxiliary agent comprises 60% sodium dodecylbenzene sulfonate and 1.5% sodium lauroamphoacetate by weight, and the balance is coconut oil fatty acid diethanolamide.

[0089] Embodiment 7:

[0090] This embodiment

[0091] The raw materials of the foaming agent include, by weight percentage, 30% of stearamide bishydroxysulfobetaine, 25% of amine oxide, 18% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 3% of methanol, 1% of auxiliary agent, and the balance is water; wherein the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroamphoacetate, and the balance is coconut oil fatty acid diethanolamide.

[0092] The preparation method of this embodiment is different from that of embodiment 1 in that the preparation method of stearamide bishydroxysulfobetaine is as follows: the above-mentioned oleic acid amidopropyl hydroxysulfobetaine is subjected to an addition reaction with hydrogen bromide to generate 10-bromo-octadecylamidopropyl hydroxysulfobetaine, the molar ratio of 10-bromo-octadecylamidopropyl hydroxysulfobetaine and dimethylamine is 1:1, the concentration of the isopropanol solution of dimethylamine is 25%, nitrogen is passed through for protection, the temperature is first slowly raised to 165° C., the reaction is carried out at a constant temperature for 10 hours, and after cooling to room temperature, the unreacted dimethylamine isopropanol solution is distilled out. After the distillation is completed, 0.5 mol / L hydrochloric acid is added for pickling, the lower layer of alkyl dimethylamine hydrochloride aqueous solution is collected, 20% sodium hydroxide solution is added to neutralize to neutrality, the oil phase is separated, and dried and filtered to obtain N, N-dimethyl-amino-octadecylamidopropyl hydroxysulfobetaine.

[0093] Embodiment 8:

[0094] The difference between this embodiment and embodiment 1 is that the raw materials of the foaming agent include, by weight percentage: 40% of stearylamide bishydroxysulfobetaine, 28% of amine oxide, 15% of C14-C18 olefin sulfonate potassium, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 3% of methanol, 1% of auxiliary agent, and the balance is water; wherein the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroylamphoacetate, and the balance is coconut oil fatty acid diethanolamide; the α-olefin sulfonate is C14-C18 olefin sulfonate potassium.

[0095] Embodiment 9:

[0096] The raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 30% of amine oxide, 15% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water; wherein the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroylamphoacetate, and the balance is coconut oil fatty acid diethanolamide;

[0097] The preparation method of this embodiment is different from that of Embodiment 2 in that, in step S3, reactant A is added to a reactor and heated, the temperature is raised to 30°C, 80% of the auxiliary agent is initially added and rapidly stirred for 5 minutes, the temperature is raised to 40°C, reactant B is added and slowly stirred for 5 minutes, the temperature is raised to 50°C, the remaining 20% ​​of the auxiliary agent is added and rapidly stirred for 5 minutes, the temperature is raised to 70°C and slowly stirred, and the foaming agent is obtained after cooling.

[0098] Embodiment 10:

[0099] The raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 32% of amine oxide, 12% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water; wherein, the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroylamphoacetate, and the balance is coconut oil fatty acid diethanolamide;

[0100] The preparation method of this embodiment is different from that of Embodiment 2 in that, in step S3, reactant A is added to a reactor and heated, the temperature is raised to 40°C, 80% of the auxiliary agent is started to be added and rapidly stirred for 10 minutes, the temperature is raised to 50°C, reactant B is added and slowly stirred for 10 minutes, the temperature is raised to 60°C, the remaining 20% ​​of the auxiliary agent is added and rapidly stirred for 10 minutes, the temperature is raised to 80°C and slowly stirred, and the foaming agent is obtained after cooling.

[0101] Embodiment 11:

[0102] The raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 36% of amine oxide, 9% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water; wherein the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroylamphoacetate, and the balance is coconut oil fatty acid diethanolamide;

[0103] The difference between the preparation method of this embodiment and that of embodiment 2 is that the rate of the rapid stirring is 120 r / min, and the rate of the slow stirring is 60 r / min.

[0104] Embodiment 12:

[0105] The raw materials of the foaming agent include, by weight percentage: 40% of stearamide bishydroxysulfobetaine, 38% of amine oxide, 8% of sodium C14-C18 olefin sulfonate, 7% of triethanolamine, 3% of perfluorododecyl carboxylate, 2% of methanol, 1% of auxiliary agent, and the balance is water; wherein the auxiliary agent includes, by weight percentage, 48% of sodium dodecylbenzene sulfonate and 1% of sodium lauroylamphoacetate, and the balance is coconut oil fatty acid diethanolamide;

[0106] The difference between the preparation method of this embodiment and that of embodiment 2 is that the rapid stirring rate is 150 r / min, and the slow stirring rate is 80 r / min.

[0107] Now, for the foaming agent prepared in each embodiment, the physical properties are measured at a resistance to mineralization of 1.0×105 mg / L, and the specific exploration is as follows:

[0108] Explore the effects of different ratios of raw materials and different processes on foaming agents;

[0109] Examples 1 to 12 are used as experimental examples for comparison;

[0110] At the same time, comparative example 1 is set: in step S3, reactant A is added to a reactor and heated to 35° C., reactant B and an auxiliary agent are added to reactant A and stirred, and other conditions remain unchanged;

[0111] Comparative Example 2: In step S3, reactant A is added to a reactor and heated to 35° C., and all the auxiliary agents are added to reactant A and mixed, and other conditions remain unchanged;

[0112] Comparative Example 3: In the preparation method of the stearamide bishydroxysulfobetaine foaming agent, no amine oxide is added, and other conditions remain unchanged;

[0113] Comparative Example 4: Sodium lauroylamphoacetate was not added to the auxiliary agent, and other conditions remained unchanged;

[0114] Comparative Example 5: The α-olefin sulfonate is composed of sodium C14-C18 olefin sulfonate and potassium C14-C18 olefin sulfonate in a mass ratio of 8:3, and other conditions remain unchanged;

[0115] The properties of the foaming agent are shown in Table 1:

[0116] Table 1 Performance test table of foaming agent under various ingredients

[0117]

[0118] It can be seen from the results in Table 1 that different ratios of raw materials and different processes have a certain influence on the performance of the foaming agent; when the mineralization degree is 1.0×105mg / L, the liquid carrying rate of the foaming agent prepared in the above Examples 1-5 is above 80%, and the liquid carrying rate of the foaming agent prepared in Examples 6-14 is also above 70%, and the foaming performance and foam stabilization performance are both good. Among them, the foaming agent prepared in Examples 2 and 5 has better performance. Considering the preparation cost, the ratio of Example 1 and the preparation method of Example 2 are the best. It can be seen from Comparative Example 1, Comparative Example 2 and Example 2 that according to the actual The foaming agent prepared by the method of Example 2 has higher salt resistance and liquid carrying capacity. It can be seen from Comparative Example 3 that the addition of amine oxide greatly improves the foaming performance, salt resistance and liquid carrying performance of the foaming agent. It can be seen from Comparative Example 4 that the addition of sodium lauroylamphoacetate in the auxiliary agent has an important effect on improving the performance of the foaming agent, further improving the salt resistance of the foaming agent. The foaming agent prepared by Comparative Example 5 has better foam stabilization performance than the foaming agents prepared in Examples 1 and 10. Among them, the formula of Example 1 or Comparative Example 5 can be selected to prepare the foaming agent according to actual needs.

[0119] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells. It is characterized in that Calculated by mass percentage, the components include 30% to 40% of stearylamide bishydroxysulfobetaine, 25% to 40% of amine oxide, 8% to 18% of α-olefin sulfonate, 5% to 8% of triethanolamine, 0.5% to 3% of fluorocarbon surfactant, 0.5% to 3.5% of methanol, 0.5% to 1.5% of auxiliary agent, and the balance is water.

2. The stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 1, It is characterized in that The auxiliary agent comprises, by mass percentage, 40% to 60% of sodium dodecylbenzene sulfonate, 0.2% to 1.5% of sodium lauroamphoacetate, and the remainder is coconut oil fatty acid diethanolamide.

3. The stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 1, It is characterized in that The fluorocarbon surfactant is perfluorododecyl carboxylate.

4. The stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 1, It is characterized in that The α-olefin sulfonate is C 14 -C 18 Sodium olefin sulfonate or C 14 -C 18 One or a mixture of two of potassium olefin sulfonates.

5. A method for preparing the stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to any one of claims 1 to 4, It is characterized in that The following steps are involved: S1, mixing stearamide bishydroxysulfobetaine, amine oxide, triethanolamine and water, heating to 30° C. to 50° C. and stirring to obtain a reactant A; S2, mixing a fluorocarbon surfactant, methanol, α-olefin sulfonate and water, heating to 70° C. to 80° C. and stirring to obtain a reactant B; S3, add reactant A into the reactor and heat it to 30℃~40℃, add 80% of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 40℃~50℃, add reactant B and stir slowly for 5min~10min, then raise the temperature to 50℃~60℃, add the remaining 20% ​​of the auxiliary agent and stir rapidly for 5min~10min, then raise the temperature to 70℃~80℃ and stir slowly, and obtain the foaming agent after cooling.

6. A method for preparing a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 5, It is characterized in that The preparation process of stearamide bishydroxysulfobetaine in S1 comprises the following steps: S101, at 40°C, N,N-dimethyl-1,3-propylenediamine was added dropwise to oleic acid, and then the temperature was raised to 155°C. Under nitrogen protection, the reaction was carried out for 5h to 8h to obtain N,N-dimethyl-N′-oleic acid acyl propylamine; S102, mixing N,N-dimethyl-N′-oleyl propylamine with an ethanol aqueous solution, adding sodium 3-chloro-2-hydroxypropanesulfonate dropwise, adjusting the pH to 8 under nitrogen protection, stirring and reacting at 85° C. for 7 h to 9 h to obtain crude oleamidopropyl hydroxysulfobetaine, and then removing impurities by reduced pressure distillation to obtain pure oleamidopropyl hydroxysulfobetaine; S103, reacting pure oleic acid amidopropyl hydroxysulfobetaine with hydrogen bromide to generate 10-bromo-octadecylamidopropyl hydroxysulfobetaine, then mixing 10-bromo-octadecylamidopropyl hydroxysulfobetaine with an isopropanol solution of dimethylamine, passing nitrogen gas for protection, slowly heating to 165° C., reacting at a constant temperature for 8 h to 10 h, cooling to room temperature, distilling out the unreacted isopropanol solution of dimethylamine, then adding hydrochloric acid for pickling, collecting the lower layer of alkyldimethylamine hydrochloride aqueous solution, then adding sodium hydroxide solution to neutralize to neutrality, separating the oil phase, drying and filtering to obtain N,N-dimethyl-amino-octadecylamidopropyl hydroxysulfobetaine; S104, sodium 3-chloro-2-hydroxypropanesulfonate is added dropwise to N,N-dimethyl-amino-octadecylamidopropylhydroxysulfobetaine, and the pH is adjusted to 8 under nitrogen protection. The reaction is stirred at 90° C. for 9 h to 10 h to obtain crude stearamide bishydroxysulfobetaine, and then impurities are removed by reduced pressure distillation to obtain pure stearamide bishydroxysulfobetaine.

7. The method for preparing the stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 6, It is characterized in that The molar ratio of oleic acid to N,N-dimethyl-1,3-propylenediamine in S101 is 1:1; the volume ratio of ethanol to water in the ethanol aqueous solution in S102 is 15:85; the molar ratio of N,N-dimethyl-N′-oleic acid acyl propylamine to sodium 3-chloro-2-hydroxypropanesulfonate is 8:

10.

8. The method for preparing a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 6, It is characterized in that The molar ratio of 10-bromo-octadecylamidopropyl hydroxysulfobetaine to dimethylamine in S103 is 1-3:1; the volume concentration of the isopropanol solution of dimethylamine is 25%; the concentration of hydrochloric acid is 0.5 mol / L; and the mass concentration of the sodium hydroxide solution is 20%.

9. The method for preparing a stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to claim 5, It is characterized in that The rapid stirring rate in S3 is 120 r / min to 150 r / min, and the slow stirring rate is 60 r / min to 80 r / min.

10. Use of the stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells according to any one of claims 1 to 4 or the stearamide bishydroxysulfobetaine composite foaming agent for low permeability gas wells prepared by the method according to any one of claims 5 to 9 in the exploitation of low permeability gas fields.

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