Multi-sulfo gemini surfactant type foaming agent as well as preparation method and application thereof

Abstract

The invention discloses a multi-sulfo gemini surfactant type foaming agent as well as a preparation method and application thereof. The method comprises the following steps: (1) dissolving straight-chain fatty acid and p-aminophenol in a first organic solvent, adding ethyl acetate and sodium borohydride for reaction, and performing first post-treatment to obtain 4-(alkylamide) phenol; (2) dissolving short-chain alkyl glycol and maleic anhydride in a second organic solvent, adding anhydrous sodium acetate for reaction, and performing second post-treatment to obtain short-chain alkanol maleic acid diester; (3) adding 4-(alkylamide) phenol into the short-chain alkanol maleic acid diester, adding zinc oxide for reaction, and performing third post-treatment to obtain a gemini intermediate product; and (4) adjusting the pH value of the gemini intermediate product, adding a sodium hydrogen sulfite aqueous solution, and carrying out fourth post-treatment. The method has the following advantages: (1) the adsorption loss in a reservoir is small, and deep migration can be realized; (2) efficient foaming under low-concentration and low-power conditions; (3) the plugging strength is high; and (4) the adaptability is good.

Description

Technical Field

[0001] The present invention belongs to the field of heavy oil exploitation, and particularly relates to a multi-sulfonate gemini surfactant-based foaming agent, a preparation method thereof, and an application thereof. Background Art

[0002] During the thermal recovery development process of heavy oil reservoirs, affected by reservoir heterogeneity, problems such as uneven steam absorption and steam channeling are likely to occur, seriously affecting the thermal recovery development effect.

[0003] Nitrogen foam profile control is an important means in the thermal recovery of heavy oil reservoirs, with advantages such as low cost, selective plugging, no engineering risks, and deep migration. It can effectively adjust the steam absorption profile, plug high-permeability channels, expand the steam sweep, and improve the thermal utilization rate. For example, Chinese Patent Application CN 105672961A discloses an overall profile control process of nitrogen foam during the exploitation of heavy oil reservoirs, including a fixed station, a nitrogen foam generator, a nitrogen foam repeating generator, a nitrogen foam distributor, and a nitrogen foam metering device connected in sequence. The fixed station includes a nitrogen vehicle group, a steam boiler, and a foaming agent injection skid-mounted unit. The nitrogen vehicle group, the steam boiler, and the foaming agent injection skid-mounted unit are all connected to the nitrogen foam generator. At least one nitrogen foam metering device is provided and connected to the corresponding wellhead. However, after years of development, the steam sweep approaches the limit radius, the oil saturation in the near-well area of the old thermal recovery area is low, and a large amount of remaining oil still exists between wells, which requires the foaming agent to have the ability of "deep migration and high-strength plugging in the deep formation".

[0004] Conventional foaming agents are mainly anionic or anionic-nonionic surfactants, such as α-olefin sulfonates, petroleum sulfonates, alkylbenzene sulfonates, fatty alcohol polyoxyethylene ether sulfonates, fatty alcohol polyoxyethylene ether carboxylates, etc. For example, Chinese Patent Application CN 109943307A discloses a foam solution for profile control and plugging during heavy oil thermal recovery, its preparation method, a foam system, and a method for profile control and plugging. The foam system includes a gas phase and a liquid phase. The gas phase is nitrogen, and the liquid phase is the foam solution. The foam solution contains a foaming agent, oil-containing sludge mixed coal combustion ash, a dispersant, and water. Based on the total weight of the foam solution, the content of the foaming agent is 1-1.5% by weight, the content of the oil-containing sludge mixed coal combustion ash is 4-6% by weight, the content of the dispersant is 0.25-0.5% by weight, and the content of water is 92-94.75% by weight. Among them, the foaming agent is a mixture of sodium hexadecyl benzene sulfonate and tea saponin. Chinese Patent Application CN 111019625A, a low interfacial tension viscosity-reducing foaming agent for conventional heavy oil reservoirs, its preparation method and application, belongs to the technical field of surfactants, and can solve technical problems such as the easy failure of current foam flooding agents in the formation and the difficulty in forming a stable profile control and plugging ability. In the low interfacial tension viscosity-reducing foaming agent for conventional heavy oil reservoirs, the mass concentration of alkyl polyglycoside is 10-50%, the mass concentration of α-olefin sulfonate is 5-30%, the mass concentration of ionic liquid is 5-20%, and the balance is water. Chinese Patent Application CN 112694883A discloses a foam composition for improving the recovery rate of heavy oil reservoirs and its preparation method. The foam composition includes: in parts by weight, 1 part of a long-chain polyether anionic surfactant, 0.1-50 parts of a long-chain nitrogen-containing compound, and 0.1-5 parts of a cationic polyelectrolyte or polymer; the preparation method includes: the components are mixed according to the dosage to obtain the foam composition. This kind of foaming agent is mainly a single-chain structure, with loose molecular arrangement at the gas-liquid interface and not high enough surface activity. It can effectively foam and plug in the high-concentration area near the wellbore, but in the dilution process of formation migration and the low-concentration area deep in the formation, the system is difficult to play a role and it is difficult to meet the profile control requirements of multi-thermal recovery old heavy oil reservoirs. Summary of the Invention

[0005] Object of the Invention: Aiming at the above technical problems existing in the prior art, the present invention discloses a multi-sulfonate gemini surfactant-based foaming agent, its preparation method and application. The multi-sulfonate gemini surfactant-based foaming agent has high surface activity, can quickly form small and uniform bubbles under high-temperature conditions, has strong foaming and foam-stabilizing abilities, can efficiently foam and plug under low concentration and low dynamic conditions deep in the formation, can effectively plug steam channeling channels, expand steam sweep, and thus improve the huff and puff effect.

[0006] Technical Solution: A multi-sulfonate gemini surfactant-based foaming agent has a structure of formula (1):

[0007]

[0008] Wherein: R 1 is a straight-chain aliphatic hydrocarbon group with 8 to 24 carbon atoms, preferably a straight-chain aliphatic hydrocarbon group with 12 to 18 carbon atoms;

[0009] R 2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl;

[0010] M is one of an alkali metal, an alkaline earth metal or an ammonium group, preferably one of K, Na, ammonium.

[0011] The preparation method of the above multi-sulfonate gemini surfactant type foaming agent specifically includes the following steps in terms of mole parts:

[0012] (1) Under the protection of nitrogen or inert gas, dissolve 2 parts of straight-chain fatty acid and 2 to 2.4 parts of p-aminophenol in an appropriate amount of a first organic solvent, and successively add an appropriate amount of ethyl acetate and sodium borohydride thereto to obtain a mixed solution. React the mixed solution at 140 to 180 °C for at least 3 h to obtain a reaction solution, and then perform a first post-treatment on the reaction to obtain 4-(alkylamide)phenol;

[0013] (2) Under the protection of nitrogen or inert gas, dissolve 1 to 1.2 parts of short-chain alkyl diol and 2 parts of maleic anhydride in an appropriate amount of a second organic solvent, and then add an appropriate amount of anhydrous sodium acetate thereto. React the mixture at 70 to 110 °C for at least 1 h to obtain a reaction solution, and perform a second post-treatment on the reaction solution to obtain short-chain alkanol maleic acid diester;

[0014] (3) Under the protection of nitrogen or inert gas, add the 4-(alkylamide)phenol obtained in step (1) to the short-chain alkanol maleic acid diester obtained in step (2), and add an appropriate amount of zinc oxide thereto. React the mixture at 110 to 150 °C for at least 3 h to obtain a reaction solution, and perform a third post-treatment on the reaction solution to obtain a liquid gemini intermediate;

[0015] (4) Use an alkali solution to adjust the pH value of the gemini intermediate to 6.5 to 7.5, and then slowly add an aqueous sodium bisulfite solution to obtain a mixed solution. React the mixed solution at 100 to 160 °C for at least 5 h to obtain a reaction solution, and then perform a fourth post-treatment on the reaction solution to obtain the multi-sulfonate gemini surfactant type foaming agent.

[0016] Furthermore, the straight-chain fatty acid in step (1) is a straight-chain fatty acid with 8 to 24 carbon atoms, preferably a straight-chain fatty acid with 12 to 18 carbon atoms.

[0017] Furthermore, the first organic solvent in step (1) is one of dimethyl sulfoxide, dichloromethane, diethyl ether, acetone;

[0018] The second organic solvent described in step (2) is one of acetone, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate, and diethyl ether.

[0019] Furthermore, the mass of the first organic solvent used in step (1) is 5 - 20 times, preferably 10 - 15 times, the sum of the masses of the straight-chain fatty acid and p-aminophenol.

[0020] Furthermore, the mass ratio of the amount of ethyl acetate used in step (1) to the amount of the straight-chain fatty acid used is (0.3 - 1):100, preferably (0.4 - 0.6):100.

[0021] Furthermore, the mass ratio of the amount of sodium borohydride used in step (1) to the amount of the straight-chain fatty acid used is (0.2 - 0.8):100, preferably (0.3 - 0.5):100.

[0022] Furthermore, the specific steps of the first post-treatment in step (1) are: extracting the product in the reaction solution with ethyl acetate and distilled water, then washing with distilled water, rotary evaporation, and recrystallization.

[0023] Furthermore, the reaction time in step (1) is 3 - 8 h;

[0024] The reaction time of the reaction in step (2) is 1 - 6 h;

[0025] The reaction time of the reaction in step (3) is 3 - 8 h;

[0026] The reaction time of the reaction in step (4) is 5 - 10 h.

[0027] Furthermore, the short-chain alkyl diol described in step (2) is at least one of ethylene glycol, 1,2-propanediol, and 1,2-butanediol, preferably ethylene glycol.

[0028] Furthermore, the volume of the second organic solvent used in step (2) is 20 - 40 times, preferably 25 - 35 times, the volume of the short-chain alkyl diol used in step (2).

[0029] Furthermore, the mass ratio of the amount of anhydrous sodium acetate used in step (2) to the amount of the short-chain alkyl diol used is (0.2 - 1):100, preferably (0.4 - 0.6):100.

[0030] Furthermore, the specific steps of the second post-treatment in step (2) are: first rotary evaporating the reaction solution, and then recrystallizing.

[0031] Further, the mass ratio of the amount of zinc oxide used in step (3) to the amount of 4-(alkylamide)phenol used in step (3) is (0.3 - 0.8):100, preferably (0.4 - 0.6):100.

[0032] Further, the specific steps of the third post-treatment in step (3) are as follows: first, extract the reaction solution with ethyl acetate, and then perform rotary evaporation.

[0033] Further, the base used in the alkaline solution in step (4) is at least one of alkali metal hydroxides and alkaline earth metal hydroxides, preferably sodium hydroxide and / or potassium hydroxide.

[0034] Further, the molar ratio of sodium bisulfite to the gemini intermediate in the mixed solution in step (4) is (4 - 5):1.

[0035] Further, the mass fraction of the aqueous sodium bisulfite solution in step (4) is 20% - 40%, preferably 30%.

[0036] Further, the specific steps of the fourth post-treatment in step (4) are as follows: put the reaction solution into distilled water for extraction, filter to remove insoluble substances, collect the filtrate, perform rotary evaporation and recrystallization, then collect the crystals, wash them with absolute ethanol, and perform rotary evaporation.

[0037] Further, the structure of 4-(alkylamide)phenol described in step (1) is shown in formula (2):

[0038]

[0039] wherein, R 1 is a straight-chain aliphatic hydrocarbon group with 8 - 24 carbon atoms, preferably a straight-chain aliphatic hydrocarbon group with 12 - 18 carbon atoms.

[0040] Further, the structure of the short-chain alkanol maleic acid diester described in step (2) is shown in formula (3):

[0041]

[0042] wherein, R 2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl.

[0043] Further, the structure of the gemini intermediate described in step (3) is shown in formula (4):

[0044]

[0045]

[0046] wherein, R 1It is a C8-C24 straight chain aliphatic hydrocarbon group, preferably a C12-C18 straight chain aliphatic hydrocarbon group;

[0047] R 2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl.

[0048] A polysulfone gemini surfactant type foaming agent, prepared by any of the above-mentioned preparation methods.

[0049] Application of any of the above-mentioned polysulfone gemini surfactant-type foaming agents in thermal recovery of heavy oil reservoirs.

[0050] Furthermore, the specific steps of the application are:

[0051] In the case of pre-injection or with steam injection, any of the above-mentioned polysulfone gemini surfactant type foaming agents is dissolved in an appropriate amount of water to obtain a polysulfone gemini surfactant type foaming agent solution with a mass concentration of 0.1%-1.5%, and then it is injected into the target formation from the wellbore at the same time with gas in a certain proportion.

[0052] Furthermore, the gas is nitrogen, air, CO 2 , at least one of flue gas.

[0053] Furthermore, the volume ratio of the polysulfone gemini surfactant foaming agent solution to the gas is 1:(0.6-4).

[0054] The polysulfone gemini surfactant foaming agent disclosed in the present invention has a gemini structure and contains multiple active sulfonic acid groups. The surfactant molecules are closely arranged at the gas-liquid interface, with a cmc of 28 mg / L. It has high surface activity, a dense foam surface film, and can quickly form small and uniform foam under high temperature conditions. It has strong foaming and stabilizing abilities and strong regeneration ability after bursting. It can efficiently foam and plug under low concentration and low power conditions in deep formations, effectively plug steam channeling channels, expand steam sweep, and thus improve throughput effects.

[0055] Beneficial effects: The polysulfone gemini surfactant foaming agent disclosed in the present invention and its preparation method and application have the following beneficial effects:

[0056] (1) The foaming agent of the present invention has low adsorption loss in the reservoir, can be deeply transported, and the static adsorption amount can reach 0.1 mg / g;

[0057] (2) The foaming agent of the present invention can foam efficiently under low concentration and low power conditions in deep formations, with a cmc as low as 28 mg / L, high surface activity, and a use concentration as low as 0.1%;

[0058] ​(3) The foaming agent of the present invention has high plugging strength, and the resistance factor is 80 - 600 under the conditions of 80 - 250 °C;

[0059] (4) The present invention has good adaptability. The foaming agent system is applicable to a salinity of 0 - 100000 mg / L or more, and the calcium and magnesium ions are 0 - 5000 mg / L. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 It is a flow chart of a preparation method of a multi-sulfonated gemini surfactant type foaming agent disclosed by the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0061] The following is a detailed description of the specific embodiments of the present invention.

[0062] The synthesis route of the preparation method of the multi-sulfonated gemini surfactant type foaming agent disclosed by the present invention is as follows:

[0063] ①

[0064]

[0065] ②

[0066]

[0067] ③

[0068]

[0069] Example 1

[0070] A multi-sulfonated gemini surfactant type foaming agent G1, which has the structure of formula (1):

[0071]

[0072] Wherein: R 1 is a lauric acid group of C12;

[0073] R 2 is hydrogen;

[0074] M is Na.

[0075] The preparation method of the above multi-sulfonated gemini surfactant type foaming agent G1 specifically includes the following steps in terms of mole parts:

[0076] (1) Under nitrogen protection, dissolve 2 parts of lauric acid and 2.2 parts of p-aminophenol in an appropriate amount of a first organic solvent, and successively add an appropriate amount of ethyl acetate and sodium borohydride thereto to obtain a mixed solution. React the mixed solution at 160 °C for 5 h to obtain a reaction solution, and then perform a first post-treatment on the reaction to obtain 4-(alkylamide)phenol;

[0077] (2) Under nitrogen protection, 1.1 parts of short-chain alkyl diol and 2 parts of maleic anhydride are dissolved in an appropriate amount of a second organic solvent, and then an appropriate amount of anhydrous sodium acetate is added thereto. The reaction is carried out at 85 °C for 4 h to obtain a reaction solution. After the second post-treatment of the reaction solution, a short-chain alkanol maleic acid diester is obtained.

[0078] (3) Under nitrogen protection, the 4-(alkylamide)phenol obtained in step (1) is added to the short-chain alkanol maleic acid diester obtained in step (2), and an appropriate amount of zinc oxide is added thereto. The reaction is carried out at 140 °C for 5 h to obtain a reaction solution. After the third post-treatment of the reaction solution, a liquid gemini intermediate is obtained.

[0079] (4) The pH value of the gemini intermediate is adjusted to 7 using an alkali solution, and then an aqueous sodium bisulfite solution is slowly added to obtain a mixed solution. The mixed solution is reacted at 150 °C for 6 h to obtain a reaction solution, and then the reaction solution is subjected to a fourth post-treatment to obtain the multi-sulfonate gemini surfactant type foaming agent G1.

[0080] Further, the lauric acid described in step (1) is a straight-chain fatty acid with 12 carbon atoms.

[0081] Further, the first organic solvent described in step (1) is dimethyl sulfoxide;

[0082] The second organic solvent described in step (2) is acetone.

[0083] Further, the mass of the first organic solvent used in step (1) is 12 times the sum of the masses of lauric acid and p-aminophenol.

[0084] Further, the mass ratio of the dosage of ethyl acetate to the dosage of lauric acid described in step (1) is 0.5:100.

[0085] Further, the mass ratio of the dosage of sodium borohydride to the dosage of lauric acid described in step (1) is 0.4:100.

[0086] Further, the specific steps of the first post-treatment in step (1) are: extracting the product in the reaction solution with ethyl acetate and distilled water, then washing with distilled water, rotary evaporation, and recrystallization.

[0087] Further, the short-chain alkyl diol described in step (2) is ethylene glycol.

[0088] Further, the volume of the second organic solvent used in step (2) is 30 times the volume of the short-chain alkyl diol used in step (2).

[0089] Further, the mass ratio of the amount of sodium acetate anhydrous to the amount of the short-chain alkyl diol described in step (2) is 0.5:100.

[0090] Further, the specific steps of the second post-treatment in step (2) are as follows: subject the reaction solution to rotary evaporation first and then recrystallization.

[0091] Further, the mass ratio of the amount of zinc oxide to the amount of 4-(alkylamide)phenol described in step (3) is 0.5:100.

[0092] Further, the specific steps of the third post-treatment in step (3) are as follows: extract the reaction solution with ethyl acetate first and then perform rotary evaporation.

[0093] Further, the base used in the base solution in step (4) is sodium hydroxide.

[0094] Further, the molar ratio of sodium bisulfite to the gemini intermediate in the mixed solution in step (4) is 4.4:1.

[0095] Further, the mass fraction of the sodium bisulfite aqueous solution in step (4) is 30%.

[0096] Further, the specific steps of the fourth post-treatment in step (4) are as follows: place the reaction solution in distilled water for extraction, filter to remove insoluble substances, collect the filtrate, perform rotary evaporation and recrystallization, then collect the crystals, wash them with absolute ethanol, and perform rotary evaporation.

[0097] Further, the structure of 4-(alkylamide)phenol described in step (1) is shown in formula (2):

[0098]

[0099] wherein, R 1 is the lauryl group of C12.

[0100] Further, the structure of the short-chain alkanol maleic acid diester described in step (2) is shown in formula (3):

[0101]

[0102] wherein, R 2 is hydrogen.

[0103] Further, the structure of the gemini intermediate described in step (3) is shown in formula (4):

[0104]

[0105] wherein, R 1is the lauroyl group of C12;

[0106] R 2 is hydrogen.

[0107] A multi-sulfonate gemini surfactant type foaming agent is prepared by the preparation method described in any one of the above.

[0108] Application of the above multi-sulfonate gemini surfactant type foaming agent G1 in the thermal recovery process of heavy oil reservoirs.

[0109] Furthermore, the specific steps of the application are as follows:

[0110] In the case of pre-injection, the multi-sulfonate gemini surfactant type foaming agent G1 described in any one of the above is dissolved in an appropriate amount of water to obtain a multi-sulfonate gemini surfactant type foaming agent solution with a mass concentration of 0.3%, and then it is simultaneously injected into the target formation from the wellbore with gas in a certain proportion to block the high-permeability channel and expand the steam sweep.

[0111] Furthermore, the gas is nitrogen.

[0112] Furthermore, the volume ratio of the multi-sulfonate gemini surfactant type foaming agent solution to the gas is 1:0.5.

[0113] Example 2

[0114] A multi-sulfonate gemini surfactant type foaming agent G2 has the structure of formula (1):

[0115]

[0116] Wherein: R 1 is the stearoyl group of C18;

[0117] R 2 is methyl;

[0118] M is K.

[0119] The preparation method of the above multi-sulfonate gemini surfactant type foaming agent G2 specifically includes the following steps in terms of mole parts:

[0120] (1), Under the protection of helium, 2 parts of stearic acid and 2 parts of p-aminophenol are dissolved in an appropriate amount of the first organic solvent, and an appropriate amount of ethyl acetate and sodium borohydride are successively added thereto to obtain a mixed solution, and the reaction is carried out at 140 °C for 8 h to obtain a reaction solution, and then the first post-treatment is carried out on the reaction to obtain 4-(alkylamide)phenol;

[0121] (2) Under helium protection, dissolve 1 part of short-chain alkyl diol and 2 parts of maleic anhydride in an appropriate amount of a second organic solvent, then add an appropriate amount of anhydrous sodium acetate thereto, and react at 70 °C for 6 h to obtain a reaction solution. After performing a second post-treatment on the reaction solution, a short-chain alkanol maleic acid diester is obtained;

[0122] (3) Under helium protection, add the 4-(alkylamide)phenol obtained in step (1) to the short-chain alkanol maleic acid diester obtained in step (2), and add an appropriate amount of zinc oxide thereto. React at 110 °C for 8 h to obtain a reaction solution. After performing a third post-treatment on the reaction solution, a liquid gemini intermediate is obtained;

[0123] (4) Use an alkali solution to adjust the pH value of the gemini intermediate to 6.5, then slowly add an aqueous solution of sodium bisulfite to obtain a mixed solution. React the mixed solution at 100 °C for 10 h to obtain a reaction solution, and then perform a fourth post-treatment on the reaction solution to obtain the multi-sulfonate gemini surfactant-type foaming agent G2.

[0124] Further, the stearic acid in step (1) is a straight-chain fatty acid with 18 carbon atoms.

[0125] Further, the first organic solvent in step (1) is dichloromethane;

[0126] The second organic solvent in step (2) is dimethyl sulfoxide.

[0127] Further, the mass of the first organic solvent used in step (1) is 5 times the sum of the masses of stearic acid and p-aminophenol. In another embodiment, the mass of the first organic solvent used in step (1) is 10 times the sum of the masses of stearic acid and p-aminophenol.

[0128] Further, the mass ratio of the amount of ethyl acetate used to the amount of stearic acid used in step (1) is 0.3:100. In another embodiment, the mass ratio of the amount of ethyl acetate used to the amount of stearic acid used in step (1) is 0.4:100.

[0129] Further, the mass ratio of the amount of sodium borohydride used to the amount of stearic acid used in step (1) is 0.2:100. In another embodiment, the mass ratio of the amount of sodium borohydride used to the amount of stearic acid used in step (1) is 0.3:100.

[0130] Further, the specific steps of the first post-treatment in step (1) are: extract the product in the reaction solution with ethyl acetate and distilled water, then wash with distilled water, and perform rotary evaporation and recrystallization.

[0131] Further, the short-chain alkyl diol in step (2) is 1,2-propanediol.

[0132] Further, the volume of the second organic solvent used in step (2) is 20 times the volume of the short-chain alkyl diol used in step (2). In another embodiment, the volume of the second organic solvent used in step (2) is 25 times the volume of the short-chain alkyl diol used in step (2).

[0133] Further, the mass ratio of the amount of sodium acetate anhydrous used in step (2) to the amount of the short-chain alkyl diol used is 0.2:100. In another embodiment, the mass ratio of the amount of sodium acetate anhydrous used in step (2) to the amount of the short-chain alkyl diol used is 0.4:100.

[0134] Further, the specific steps of the second post-treatment in step (2) are as follows: first rotary evaporate the reaction solution, and then recrystallize it.

[0135] Further, the mass ratio of the amount of zinc oxide used in step (3) to the amount of 4-(alkylamide)phenol used in step (3) is 0.3:100. In another embodiment, the mass ratio of the amount of zinc oxide used in step (3) to the amount of 4-(alkylamide)phenol used in step (3) is 0.4:100.

[0136] Further, the specific steps of the third post-treatment in step (3) are as follows: first extract the reaction solution with ethyl acetate, and then rotary evaporate it.

[0137] Further, the base used in the alkali solution in step (4) is potassium hydroxide.

[0138] Further, the molar ratio of sodium bisulfite to the gemini intermediate product in the mixed solution in step (4) is 4:1.

[0139] Further, the mass fraction of the aqueous sodium bisulfite solution in step (4) is 20%.

[0140] Further, the specific steps of the fourth post-treatment in step (4) are as follows: put the reaction solution into distilled water for extraction, filter to remove insoluble substances, collect the filtrate, rotary evaporate and recrystallize, then collect the crystals, wash them with absolute ethanol, and rotary evaporate.

[0141] Further, the structure of 4-(alkylamide)phenol described in step (1) is shown in formula (2):

[0142]

[0143] Among them, R 1 is a stearic acid group of C18.

[0144] Further, the structure of the short-chain alkanol maleate diester described in step (2) is shown in formula (3):

[0145]

[0146] Among them, R 2 is methyl.

[0147] Further, the structure of the gemini intermediate product described in step (3) is shown in formula (4):

[0148]

[0149] Among them, R 1 is a stearic acid group of C18;

[0150] R 2 is methyl.

[0151] A multi-sulfonate gemini surfactant type foaming agent is prepared by the preparation method described in any one of the above.

[0152] Application of the above multi-sulfonate gemini surfactant type foaming agent G2 in the thermal recovery process of heavy oil reservoirs.

[0153] Further, the specific steps of the application are as follows:

[0154] In the case of pre-injection, the above multi-sulfonate gemini surfactant type foaming agent G2 is dissolved in an appropriate amount of water to obtain a multi-sulfonate gemini surfactant type foaming agent solution with a mass concentration of 0.1%, and then it is simultaneously injected into the target formation from the wellbore with gas in a certain ratio to block the high-permeability channel and expand the steam sweep.

[0155] Further, the gas is air.

[0156] Further, the volume ratio of the multi-sulfonate gemini surfactant type foaming agent solution to the gas is 1:0.6.

[0157] Example 3

[0158] A multi-sulfonate gemini surfactant type foaming agent G3 has the structure of formula (1):

[0159]

[0160] Among them: R 1 is a palmitic acid group of C16;

[0161] R 2 is ethyl;

[0162] M is ammonium.

[0163] The preparation method of the above-mentioned multi-sulfonate gemini surfactant type foaming agent G3 specifically includes the following steps in terms of molar parts:

[0164] (1) Under the protection of argon, dissolve 2 parts of palmitic acid and 2.4 parts of p-aminophenol in an appropriate amount of a first organic solvent, and successively add an appropriate amount of ethyl acetate and sodium borohydride thereto to obtain a mixed solution. React the mixed solution at 180 °C for 3 h to obtain a reaction solution, and then perform a first post-treatment on the reaction to obtain 4-(alkylamide)phenol;

[0165] (2) Under the protection of argon, dissolve 1.2 parts of short-chain alkyl diol and 2 parts of maleic anhydride in an appropriate amount of a second organic solvent, and then add an appropriate amount of anhydrous sodium acetate thereto. React the mixture at 110 °C for 1 h to obtain a reaction solution, and perform a second post-treatment on the reaction solution to obtain short-chain alkanol maleic acid diester;

[0166] (3) Under the protection of argon, add the 4-(alkylamide)phenol obtained in step (1) to the short-chain alkanol maleic acid diester obtained in step (2), and add an appropriate amount of zinc oxide thereto. React the mixture at 150 °C for 3 h to obtain a reaction solution, and perform a third post-treatment on the reaction solution to obtain a liquid gemini intermediate;

[0167] (4) Use an alkali solution to adjust the pH value of the gemini intermediate to 7.5, then slowly add an aqueous solution of sodium bisulfite to obtain a mixed solution. React the mixed solution at 160 °C for 5 h to obtain a reaction solution, and then perform a fourth post-treatment on the reaction solution to obtain the multi-sulfonate gemini surfactant type foaming agent G3.

[0168] Further, the palmitic acid described in step (1) is a straight-chain fatty acid of C16.

[0169] Further, the first organic solvent described in step (1) is diethyl ether. In another embodiment, the first organic solvent described in step (1) is acetone.

[0170] Further, the second organic solvent described in step (2) is tetrahydrofuran. In another embodiment, the second organic solvent described in step (2) is ethyl acetate. In another embodiment, the second organic solvent described in step (2) is one of diethyl ether.

[0171] Further, the mass of the first organic solvent used in step (1) is 20 times the sum of the masses of palmitic acid and p-aminophenol. In another embodiment, the mass of the first organic solvent used in step (1) is 15 times the sum of the masses of palmitic acid and p-aminophenol.

[0172] Further, the mass ratio of the amount of ethyl acetate to the amount of palmitic acid in step (1) is 1:100. In another embodiment, the mass ratio of the amount of ethyl acetate to the amount of palmitic acid in step (1) is 0.6:100.

[0173] Further, the mass ratio of the amount of sodium borohydride to the amount of palmitic acid in step (1) is 0.8:100. In another embodiment, the mass ratio of the amount of sodium borohydride to the amount of palmitic acid in step (1) is 0.5:100.

[0174] Further, the specific steps of the first post-treatment in step (1) are: extracting the product in the reaction solution with ethyl acetate and distilled water, then washing with distilled water, rotary evaporation, and recrystallization.

[0175] Further, the short-chain alkyl diol in step (2) is 1,2-butanediol.

[0176] Further, the volume of the second organic solvent used in step (2) is 40 times the volume of the short-chain alkyl diol used in step (2). In another embodiment, the volume of the second organic solvent used in step (2) is 35 times the volume of the short-chain alkyl diol used in step (2).

[0177] Further, the mass ratio of the amount of anhydrous sodium acetate to the amount of short-chain alkyl diol in step (2) is 1:100. In another embodiment, the mass ratio of the amount of anhydrous sodium acetate to the amount of short-chain alkyl diol in step (2) is 0.6:100.

[0178] Further, the specific steps of the second post-treatment in step (2) are: first rotary evaporating the reaction solution, and then recrystallizing.

[0179] Further, the mass ratio of the amount of zinc oxide to the amount of 4-(alkylamide)phenol in step (3) is 0.8:100. In another embodiment, the mass ratio of the amount of zinc oxide to the amount of 4-(alkylamide)phenol in step (3) is 0.6:100.

[0180] Further, the specific steps of the third post-treatment in step (3) are: first extracting the reaction solution with ethyl acetate, and then rotary evaporating.

[0181] Further, the base used in the base solution in step (4) is ammonia water.

[0182] Further, the molar ratio of sodium bisulfite to the gemini intermediate in the mixed solution in step (4) is 5:1.

[0183] Further, the mass fraction of the aqueous sodium bisulfite solution in step (4) is 40%.

[0184] Further, the specific steps of the fourth post-treatment in step (4) are as follows: putting the reaction solution into distilled water for extraction, filtering to remove insoluble substances, collecting the filtrate, performing rotary evaporation and recrystallization, then collecting the crystals, washing them with absolute ethanol, and performing rotary evaporation.

[0185] Further, the structure of the 4-(alkylamide)phenol in step (1) is shown in formula (2):

[0186]

[0187]

[0188] wherein, R 1 is a palmitoyl group of C16.

[0189] Further, the structure of the short-chain alkanol maleic acid diester in step (2) is shown in formula (3):

[0190]

[0191] wherein, R 2 is ethyl.

[0192] Further, the structure of the gemini intermediate in step (3) is shown in formula (4):

[0193]

[0194] wherein, R 1 is a palmitoyl group of C16;

[0195] R 2 is ethyl.

[0196] A multi-sulfonate gemini surfactant type foaming agent is prepared by the preparation method described in any one of the above.

[0197] The application of the above multi-sulfonate gemini surfactant type foaming agent G3 in the thermal recovery process of heavy oil reservoirs.

[0198] Further, the specific steps of the application are as follows:

[0199] In the case of steam injection, the above-mentioned multi-sulfonate gemini surfactant type foaming agent G3 is dissolved in an appropriate amount of water to obtain a multi-sulfonate gemini surfactant type foaming agent solution with a mass concentration of 1.5%. Then, it and a gas are simultaneously injected into the target formation from the wellbore in a certain proportion to block the high-permeability channels and expand the steam sweep. Further, the gas is CO 2 . In another embodiment, the gas is flue gas.

[0200] Further, the volume ratio of the multi-sulfonate gemini surfactant type foaming agent solution to the gas is 1:4.

[0201] Example 4

[0202] It is substantially the same as Example 1, except that:

[0203] 1. The substituent R of the product multi-sulfonate gemini surfactant type foaming agent G4 in Example 4 1 is n-octyl.

[0204] 2. In the preparation method of Example 4, the straight-chain fatty acid used is a straight-chain fatty acid with C8.

[0205] Example 5

[0206] It is substantially the same as Example 1, except that:

[0207] 1. The substituent R of the product multi-sulfonate gemini surfactant type foaming agent G5 in Example 5 1 is a straight-chain aliphatic hydrocarbon group with C24.

[0208] 2. In the preparation method of Example 5, the straight-chain fatty acid used is a straight-chain fatty acid with C24.

[0209] Example 6

[0210] It is substantially the same as Example 1, except that:

[0211] 1. The substituent M of the product multi-sulfonate gemini surfactant type foaming agent G6 in Example 6 is Mg.

[0212] 2. In the preparation method of Example 6, the base used in the base solution in step (4) is magnesium hydroxide.

[0213] In another embodiment, the base used in the base solution in step (4) is beryllium hydroxide. In another embodiment, the base used in the base solution in step (4) is calcium hydroxide.

[0214] Performance analysis

[0215] The water used in this experiment is the produced water from Block F of Shengli Oilfield, with a total salinity of 18,568 mg / L, among which the Ca 2+ content is 1,679 mg / L, and the Mg 2+ content is 241 mg / L.

[0216] The critical micelle concentrations (cmc), foaming volumes, half-lives, and resistance factors of the multi-sulfonate gemini surfactant-based foaming agents G1, G2, G3, G4, G5, and G6 prepared in Examples 1-6 of the present invention, as well as the commercially available foaming agents SFM-1 and SFM-2, were respectively tested and evaluated.

[0217] At room temperature, a kruss surface tensiometer was used to measure the surface tension at different foaming agent concentrations to obtain the critical micelle concentration (cmc).

[0218] The test methods for the foaming volume (200 °C), half-life (200 °C), and resistance factor (80 °C, 200 °C, 250 °C) refer to Q / SH10201967—2020 "General Technical Conditions for High-Temperature Foaming Agents for Steam Huff and Puff". The use concentration of the foaming agent is 0.1%. The test results are shown in Table 1.

[0219] Table 1 Performance Test Results

[0220]

[0221]

[0222] According to the above evaluation results, the critical micelle concentrations (cmc) of the multi-sulfonate gemini surfactant-based foaming agents G1, G2, G3, G4, G5, and G6 prepared in Examples 1-6 of the present invention are about 28 mg / L, which is much lower than the cmc values of the commercially available foaming agents SFM-1 and SFM-2, indicating that the surface activity of the foaming agent of the present invention is much higher than that of the commercially available foaming agents SFM-1 and SFM-2.

[0223] According to the above evaluation results, it can be seen that the foaming and foam-stabilizing properties of the multi-sulfonate gemini surfactant-based foaming agents G1, G2, G3, G4, G5, and G6 prepared in Examples 1-6 of the present invention are better than those of the commercially available foaming agents SFM-1 and SFM-2.

[0224] Under the conditions of a temperature of 200 °C and a use concentration of 0.1%, the foaming volumes of the multi-sulfonate gemini surfactant-based foaming agents G1, G2, G3, G4, G5, and G6 prepared in Examples 1-6 of the present invention all reach more than 220 mL, and the half-lives are all more than 170 s. This shows that the foaming agent for thermal recovery of heavy oil reservoirs of the present invention has good foaming and foam-stabilizing abilities.

[0225] According to the above evaluation results, it can also be seen that the multi-sulfonate gemini surfactant-based foam agents G1, G2, G3, G4, G5, and G6 prepared in Examples 1-6 of the present invention all form effective plugs under the conditions of 80-250 °C. The resistance factor at 80 °C is 572-600, the resistance factor at 200 °C is 132-146, and the resistance factor at 250 °C is 80-93. The resistance factors at the same temperature are much higher than those of the commercially available foam agents SFM-1 and SFM-2, indicating a higher plugging strength. This shows that the multi-sulfonate gemini surfactant-based foam agents prepared in Examples 1-6 of the present invention have good plugging ability.

[0226] In summary, the foam agents G1, G2, G3, G4, G5, and G6 of the present invention all meet the relevant requirements of the oilfield, and have excellent comprehensive performance compared with commercially available foaming agents, and can meet the development needs of multi-round steam injection heavy oil reservoirs.

[0227] The above has made a detailed description of the embodiments of the present invention. However, the present invention is not limited to the above embodiments, and various changes can be made without departing from the spirit of the present invention within the scope of knowledge possessed by those of ordinary skill in the art.

Claims

1. A polysulfone gemini surfactant type foaming agent, characterized in that: It has the structure of formula (1): Wherein: R1 is a C8-C24 straight chain aliphatic hydrocarbon group, preferably a C12-C18 straight chain aliphatic hydrocarbon group; R2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl; M is one of alkali metals, alkaline earth metals or ammonium groups, preferably one of K, Na and ammonium.

2. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 1, characterized in that: In terms of molar parts, the method specifically comprises the following steps: (1) under the protection of nitrogen or inert gas, dissolving 2 parts of straight-chain fatty acid and 2 to 2.4 parts of p-aminophenol in an appropriate amount of a first organic solvent, adding appropriate amounts of ethyl acetate and sodium borohydride thereto in sequence to obtain a mixed solution, reacting at 140 to 180° C. for at least 3 hours to obtain a reaction solution, and then performing a first post-treatment on the reaction to obtain 4-(alkylamide)phenol; (2) Under the protection of nitrogen or inert gas, 1 to 1.2 parts of a short-chain alkyl glycol and 2 parts of maleic anhydride are dissolved in an appropriate amount of a second organic solvent, and then an appropriate amount of anhydrous sodium acetate is added thereto, and the reaction is carried out at 70 to 110° C. for at least 1 hour to obtain a reaction solution, and the reaction solution is subjected to a second post-treatment to obtain a short-chain alkanol maleic acid diester; (3) under the protection of nitrogen or inert gas, adding the 4-(alkylamide)phenol obtained in step (1) to the short-chain alkanol maleic acid diester obtained in step (2), adding an appropriate amount of zinc oxide thereto, reacting at 110 to 150° C. for at least 3 hours to obtain a reaction solution, and subjecting the reaction solution to a third post-treatment to obtain a liquid gemini intermediate product; (4) Using an alkaline solution, the pH value of the gemini intermediate product is adjusted to 6.5 to 7.5, and then slowly adding a sodium bisulfite aqueous solution to obtain a mixed solution, reacting the mixed solution at 100 to 160° C. for at least 5 hours to obtain a reaction solution, and then performing a fourth post-treatment on the reaction solution to obtain a polysulfonated gemini surfactant-type foaming agent.

3. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The straight-chain fatty acid described in step (1) is a C8-C24 straight-chain fatty acid, preferably a C12-C18 straight-chain fatty acid.

4. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: Step (1) the first organic solvent is one of dimethyl sulfoxide, dichloromethane, ether and acetone; In step (2), the second organic solvent is one of acetone, dimethyl sulfoxide, tetrahydrofuran, ethyl acetate and ether.

5. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The mass of the first organic solvent used in step (1) is 5-20 times, preferably 10-15 times, the sum of the mass of the straight-chain fatty acid and the p-aminophenol; The mass ratio of the amount of ethyl acetate used in step (1) to the amount of the straight-chain fatty acid used is (0.3-1):100, preferably (0.4-0.6):100; The mass ratio of the amount of sodium borohydride used in step (1) to the amount of the straight-chain fatty acid used is (0.2-0.8):100, preferably (0.3-0.5):

100.

6. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The specific steps of the first post-treatment in step (1) are: extracting the product in the reaction solution with ethyl acetate and distilled water, then washing with distilled water, rotary evaporation, and recrystallization.

7. The method for preparing a polysulfone gemini surfactant type foaming agent as claimed in claim 2, characterized in that: The reaction time in step (1) is 3-8h; The reaction time of the reaction in step (2) is 1-6h; The reaction time of the reaction in step (3) is 3-8h; The reaction time of the reaction in step (4) is 5-10 hours.

8. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The short-chain alkyl glycol described in step (2) is at least one of ethylene glycol, 1,2-propylene glycol, and 1,2-butanediol, preferably ethylene glycol; The volume of the second organic solvent used in step (2) is 20-40 times, preferably 25-35 times, the volume of the short-chain alkyl glycol used in step (2); The mass ratio of the amount of anhydrous sodium acetate used in step (2) to the amount of the short-chain alkyl glycol used is (0.2-1):100, preferably (0.4-0.6):

100.

9. The method for preparing the polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The specific steps of the second post-treatment in step (2) are: first rotary evaporating the reaction solution and then recrystallizing it.

10. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The mass ratio of the amount of zinc oxide used in step (3) to the amount of 4-(alkylamide)phenol used in step (3) is (0.3-0.8):100, preferably (0.4-0.6):

100.

11. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The specific steps of the third post-treatment described in step (3) are: first extracting the reaction solution with ethyl acetate and then rotary evaporating it.

12. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The alkali used in the alkaline solution in step (4) is at least one of an alkali metal hydroxide and an alkaline earth metal hydroxide, preferably sodium hydroxide and / or potassium hydroxide; The molar ratio of sodium bisulfite to the gemini intermediate product in the mixed solution in step (4) is (4-5): 1; The mass fraction of the sodium bisulfite aqueous solution in step (4) is 20%-40%, preferably 30%.

13. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The specific steps of the fourth post-treatment in step (4) are as follows: extracting the reaction solution in distilled water, filtering to remove insoluble matter, collecting the filtrate, rotary evaporating, recrystallizing, then collecting the crystals and washing with anhydrous ethanol and rotary evaporating.

14. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The structure of 4-(alkylamide)phenol described in step (1) is shown in formula (2): Among them, R1 is a C8-C24 straight-chain aliphatic hydrocarbon group, preferably a C12-C18 straight-chain aliphatic hydrocarbon group.

15. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The structure of the short-chain alkanol maleic acid diester described in step (2) is shown in formula (3): Wherein, R2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl.

16. The method for preparing a polysulfone gemini surfactant type foaming agent according to claim 2, characterized in that: The structure of the gemini intermediate product described in step (3) is shown in formula (4): Wherein, R1 is a C8-C24 straight chain aliphatic hydrocarbon group, preferably a C12-C18 straight chain aliphatic hydrocarbon group; R2 is one of hydrogen, methyl or ethyl, preferably hydrogen or methyl.

17. A polysulfone gemini surfactant type foaming agent, characterized in that: It is prepared by the preparation method described in any one of claims 2 to 16.

18. Use of the polysulfone gemini surfactant type foaming agent according to claim 1 or 17 in thermal recovery of heavy oil reservoirs.

19. The use according to claim 18, characterized in that The specific steps of the application are: In the case of pre-injection or co-injection with steam, the polysulfone gemini surfactant type foam agent described in any of the above items is dissolved in a suitable amount of water to obtain a polysulfone gemini surfactant type foam agent solution with a mass concentration of 0.1%-1.5%, and then it is injected into the target formation from the wellbore simultaneously with the gas in a certain proportion.

20. The use according to claim 19, characterized in that The gas is at least one of nitrogen, air, CO2 and flue gas.

21. The use according to claim 19, characterized in that The volume ratio of the polysulfone gemini surfactant type foaming agent solution to the gas is 1:(0.6-4).

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