Sulfur-inhibiting foam scrubbing agent and preparation method thereof

Abstract

The invention relates to a sulfur-inhibiting foam scrubbing agent and a preparation method thereof, and belongs to the technical field of oil-gas field development and application chemicals. The preparation method of the sulfur-inhibiting foam scrubbing agent comprises the following steps: (1) reacting long-chain alkylamine with a sulfonic compound in water under the protection of inert gas to produce a sulfonated product; (2) adding quaternary ammonium salt into the sulfonation product obtained in the step (1) for reaction to generate an ampholytic surfactant; and (3) reacting the ampholytic surfactant obtained in the step (2) with an imidazole ring compound to prepare the sulfur-inhibiting foam scrubbing agent. The sulfur-inhibiting foam scrubbing agent disclosed by the invention can form stable foam in a high-temperature acid environment, and meanwhile, can remarkably inhibit elemental sulfur deposition and promote deposited sulfur dispersion, so that sulfur deposition is reduced, and accumulated liquid discharge is promoted.

Description

TECHNICAL FIELD

[0001] The present application relates to a sulfur foam control agent and a preparation method thereof, and belongs to the technical field of oil and gas field development and application chemicals. BACKGROUND

[0002] China is rich in natural gas resources containing sulfur. In the process of exploiting high-temperature (110-130℃) and high-sulfur (>15%) natural gas wells, wellbore fluid accumulation and sulfur deposition seriously restrict the normal production of gas wells. With the advancement of the exploitation process, a large amount of formation water flows into the wellbore, and water invasion of the gas well becomes increasingly serious. At the same time, hydrogen sulfide gas generated under certain conditions can form elemental sulfur, leading to sulfur deposition. The adverse conditions of large-scale water invasion exacerbate sulfur deposition, which not only blocks the wellbore and pipeline, increases the flow resistance, but also seriously corrodes the equipment, shortens the service life of the equipment, greatly affects the exploitation efficiency of the gas well, and increases the exploitation cost.

[0003] At present, there are many solutions to this problem in the prior art, but most of them have limitations. A Chinese invention patent with publication date of March 13, 2018 and publication number CN105154053B discloses a foam control agent and a preparation method and application thereof, specifically discloses the components of the foam control agent, including betaine 25%-50%, alpha-olefin sulfonate sodium 6%-28%, coconut oil fatty acid diethanolamide 3%-14%, and fluorocarbon surfactant 10%-22%. The foam control agent mainly focuses on high-temperature resistance, high-salinity resistance, and condensate oil resistance, and achieves good foam performance through the synergistic effect of multiple surfactants.

[0004] A Chinese invention patent with publication date of May 11, 2021 and publication number CN108690590B discloses a gas well foam control agent and a preparation method and application thereof, mainly solves the technical problem of poor foam stability in the process of drainage gas recovery in high-temperature, high-salinity, acidic, and condensate gas wells, especially under acidic conditions, through the technical scheme of a foam control agent (containing anionic surfactant, zwitterionic surfactant, and foam stabilizer), which better solves the problem. The foam control agent has good foaming performance in high-temperature, high-salinity, high-condensate oil, and acidic formation water, long half-life, and large liquid carrying capacity, and can solve the problem of drainage gas recovery in high-temperature, high-salinity, acidic, and condensate gas wells.

[0005] The Chinese invention patent application file with publication date of September 24, 2024 and publication number CN118685164A discloses a sulfur dissolving agent and a preparation method thereof, specifically discloses that polysulfide and zinc alkyl mercaptide are compounded, polysulfide and zinc alkyl mercaptide can produce a synergistic effect, can quickly dissolve and deposit sulfur at room temperature, can effectively dissolve the deposited sulfur in the wellbore and gathering pipeline of a high-sulfur gas field, and the zinc alkyl mercaptide can form a dense protective film on the surface of the rubber seal, effectively reduce the rubber swelling index, avoid rubber aging failure, and at the same time, can improve the rheological property of the sulfur dissolving product and improve the sulfur dissolving efficiency of the sulfur dissolving agent. It has the advantages of no foul odor, low toxicity and low corrosion.

[0006] In summary, the commonly used foam displacement agents can only solve the drainage problem, lack effective sulfur inhibition function, and cannot carry elemental sulfur. The sulfur dissolving agent used alone for sulfur deposition problem often cannot be well compatible with the foam displacement agent, and it is difficult to simultaneously achieve efficient sulfur inhibition and foam displacement function, and cannot meet the actual needs of gas well production. Therefore, it is of great significance to develop foam agents with sulfur inhibition-liquid displacement dual functions for stable production of gas fields.

[0007] The Chinese invention patent application with publication date of April 26, 2022 and publication number CN114395386A discloses a solid foam drainage agent for gas wells with desulfurization function and a preparation method, specifically discloses that the foam drainage agent includes a desulfurizer component 10-30%, a foam drainage effective component 30-60%, a solid filler 2-30%, and a binder 0-2%. The desulfurizer component is added to the foam drainage agent, the desulfurizer component and the foam displacement agent can quickly dissolve in the bottom hole fluid, when the gas passes through, a large amount of dense foam is generated, the desulfurizer component exists in the foamed liquid film, can quickly absorb the hydrogen sulfide gas in the small bubbles, thereby achieving the effect of removing hydrogen sulfide, and the reaction products such as 3,5-di(2-hydroxyethyl)-1,3,5-thiadiazine generated by the desulfurization reaction can be carried out of the wellhead by the liquid carrying function of the foam drainage agent, achieving the purpose of desulfurization in the well; and the triazine sulfur removal agent can enhance the foam strength and liquid carrying capacity, and enhance the drainage and gas production effect of the foam drainage agent; without adding a desulfurizer separately in the well, the adding step is greatly reduced, and the bottom hole fluid of the gas well is not increased, which is beneficial to stable production of the gas well.

[0008] The Chinese invention patent application with the publication date of December 29, 2023 and the publication number of CN115124988B discloses a sulfur deposition prevention foam drainage agent, which comprises the following components in mass parts: a sulfur auxiliary dissolving agent 3-15 parts, a surfactant 35-98 parts, diethylene triamine pentamethylene phosphonic acid 3-14 parts, and hydroxy ethylene diphosphonic acid 12-28 parts; wherein the sulfur auxiliary dissolving agent comprises N-methyl-2-pyrrolidone, alkyl sulfonic acid phenyl ester, and dodecyl dimethyl amine oxide. The foam drainage agent has an appropriate amount of elemental sulfur auxiliary dissolving agent added, which can dissolve part of the elemental sulfur in the water and gas bubbles formed by the foam drainage agent in the process of drainage gas extraction, and can avoid the plugging of valves and pipe fittings by elemental sulfur in high-sulfur gas wells in a high-pressure and high-temperature downhole environment.

[0009] Although the foam agent with desulfurization / sulfur removal-liquid drainage dual functions has been developed in the prior art, it is basically used in the case where hydrogen sulfide or elemental sulfur has been generated or accumulated, and does not have the effect of inhibiting sulfur deposition. At the same time, the temperature during performance testing of the prior art is 60-80℃, and the liquid carrying and sulfur deposition inhibition effects in high-temperature formations are unknown, and the composition of the above-mentioned foam drainage agent is complex. SUMMARY

[0010] The first object of the present application is to provide a preparation method of a sulfur-inhibiting foam drainage agent, and to provide a preparation method of a foam drainage agent with good liquid carrying and sulfur inhibition effects in a high-temperature acidic environment.

[0011] The second object of the present application is to provide a sulfur-inhibiting foam drainage agent to solve the problem that the foam drainage agent with sulfur inhibition effect in the prior art has to be improved in high-temperature formations.

[0012] In order to achieve the above-mentioned objects, the technical scheme of the preparation method of the sulfur-inhibiting foam drainage agent in the present application is as follows:

[0013] The preparation method of the sulfur-inhibiting foam drainage agent comprises the following steps:

[0014] (1) reacting long-chain alkyl amine and sulfonic acid compound in water under inert gas protection to produce sulfonated product;

[0015] (2) adding quaternary ammonium salt to the sulfonated product obtained in step (1) to generate amphoteric surfactant;

[0016] (3) reacting the amphoteric surfactant obtained in step (2) and imidazole ring compound to obtain the sulfur-inhibiting foam drainage agent.

[0017] The beneficial effects of the above technical solutions are that the preparation method of the sulfur-inhibiting foam displacement agent is an opening-type invention.

[0018] As a further improvement, the mass ratio of the long-chain alkyl amine, the sulfonic acid compound, the quaternary ammonium salt and the imidazole ring compound is (15-35):(10-25):(5-15):(1-5).

[0019] As a further improvement, the long-chain alkyl group in the long-chain alkyl amine is C12-C18; and the sulfonic acid compound is chlorosulfonic acid or benzene sulfonic acid.

[0020] As a further improvement, the long-chain alkyl amine is one of dodecylamine, hexadecylamine and octadecylamine.

[0021] As a further improvement, the quaternary ammonium salt is one of trimethylammonium chloride, hexadecyltrimethylammonium bromide and tetrabutylammonium bromide.

[0022] As a further improvement, acetonitrile is added during the reaction of step (3); and the ratio of the raw materials is as follows: long-chain alkyl amine 15%-35%, sulfonic acid compound 10%-25%, quaternary ammonium salt 5%-15%, imidazole ring compound 1%-5%, acetonitrile 5%-10%, and the balance is water; and the imidazole ring compound is imidazole or 2-mercaptoimidazole.

[0023] As a further improvement, the temperature of the reaction of step (1) is 0-5℃, and the time is 2-2.5 h.

[0024] As a further improvement, the temperature of the reaction of step (2) is 25-40℃, and the time is 1-2 h.

[0025] As a further improvement, the temperature of the reaction of step (3) is 25-40℃, and the time is 2-4 h.

[0026] To achieve the above-mentioned purposes, the technical scheme of the sulfur-inhibiting foam displacement agent prepared by the preparation method of the sulfur-inhibiting foam displacement agent is as follows:

[0027] The sulfur-inhibiting foam displacement agent prepared by the preparation method of the sulfur-inhibiting foam displacement agent.

[0028] The technical scheme has the beneficial effects that the foam agent can effectively inhibit the deposition and generation of sulfur through the synergistic effect of the components, and has excellent foam drainage performance. The foam agent has a temperature resistance of 130 DEG C, a salinity resistance of 80000 mg / L, a sulfur deposition inhibition rate of more than 85% in an environment with a sulfur content of more than 15%, a foaming volume of 5 to 9 times, and a liquid carrying rate of 70% to 85%, and is suitable for the drainage gas recovery process of high-temperature and acidic gas wells. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 The Fourier infrared characterization result of the sulfur-inhibiting foam agent of Example 3 of the present application is shown in the figure.

[0030] Figure 2 The flow process schematic diagram of the gas-liquid multiphase pipe flow experimental test device in Example 7 of the present application is shown in the figure. DETAILED DESCRIPTION

[0031] In the prior art, the foam agent can mostly only solve the drainage problem, lacks effective sulfur inhibition function, and cannot carry elemental sulfur. The sulfur-dissolving agent used alone for the sulfur deposition problem often cannot be well compatible with the foam agent, and it is difficult to simultaneously achieve efficient sulfur inhibition and foam drainage functions, and cannot meet the actual needs of gas well exploitation.

[0032] The present application comprehensively considers the factors of sulfur inhibition capacity, liquid carrying capacity, high temperature resistance, and solubility, first produces a sulfonated product by reacting long-chain alkyl amine with a sulfonic acid compound under inert gas protection; then adds a quaternary ammonium salt to the sulfonated product to generate an amphoteric surfactant; and finally adds an imidazole ring compound to the obtained amphoteric surfactant to generate the sulfur-inhibiting foam agent. The sulfur-inhibiting foam agent has sulfonic acid groups (-SO3H), quaternary ammonium groups (-N + (R)4), long-chain alkyl groups, amine groups (-NH2), imidazole rings, and the synergistic effect of the components and groups can effectively inhibit the deposition and generation of sulfur, and has excellent foam drainage performance.

[0033] The hydrophilic groups (such as sulfonic acid groups (-SO3H), quaternary ammonium groups (-N +(R)4) and hydrophobic groups (such as long-chain alkyl groups) and the like can make the foam drainage agent have both sulfur inhibition and foam drainage functions. The sulfonic acid itself has a negative charge, and when it comes into contact with the surface of sulfur particles, it will make the surface of the sulfur particles have a negative charge. According to the principle of electrostatics, the same charges repel each other, and the sulfur particles with the same negative charge will generate electrostatic repulsion between them, thereby preventing them from approaching and aggregating to form large particles, so as to achieve the purpose of dispersing the sulfur particles. The foam has a liquid film structure, and the sulfur particle aggregates dispersed with the sulfonic acid group can be attached to the liquid film of the foam. Due to the buoyancy of the foam, it will carry the sulfur particle aggregates attached thereto upward, and eventually be carried to the ground. The sulfur-inhibiting foam drainage agent of the present application can form stable foam in a high-temperature acidic environment, while significantly inhibiting the deposition of elemental sulfur and promoting the dispersion of deposited sulfur, reducing sulfur deposition and promoting the drainage of accumulated liquid.

[0034] The sulfur-inhibiting foam drainage agent molecule inhibits the deposition of sulfur by undergoing electrophilic addition with sulfur hydride compounds and elemental sulfur, and the long-chain alkyl group helps to improve the adsorption performance at the gas-liquid interface and enhance the stability of the foam.

[0035] In the above reaction, the mass ratio of the long-chain alkyl amine, the sulfonic acid compound, the quaternary ammonium salt and the imidazole ring compound is (15-35):(10-25):(5-15):(1-5).

[0036] In the above reaction, the reaction conditions of the first step are N2 protection, 0-5℃, and the reaction time is 2-2.5 h; the reaction conditions of the second step are 25-40℃, and the reaction time is 1-2 h; the reaction conditions of the third step are 25-40℃, and the reaction time is 2-4 h; the temperature is strictly controlled during the process to inhibit the generation of by-products.

[0037] In the above reaction, the long-chain alkyl amine is one of dodecylamine, hexadecylamine and octadecylamine; the sulfonic acid compound is chlorosulfonic acid or benzene sulfonic acid; the quaternary ammonium salt is one of trimethylammonium chloride, hexadecyltrimethylammonium bromide and tetrabutylammonium bromide; and the imidazole ring compound is imidazole or 2-mercaptoimidazole.

[0038] In order to further improve the sulfur inhibition rate and liquid carrying rate of the sulfur-inhibiting foam drainage agent, preferably, the long-chain alkyl amine is dodecylamine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is hexadecyltrimethylammonium bromide, and the imidazole ring compound is 2-mercaptoimidazole.

[0039] Taking long-chain alkyl amine as dodecylamine, sulfonic acid compound as chlorosulfonic acid, quaternary ammonium salt as hexadecyltrimethylammonium bromide, and imidazole ring compound as 2-mercaptoimidazole as an example, the preparation process of the sulfur-inhibiting foam drainage agent of the present application is further described as follows:

[0040] The first step is the reaction of dodecylamine and chlorosulfonic acid. The reaction is a nucleophilic substitution on the amino nitrogen atom, introducing a sulfonyl chloride group (-SO2CI) on the nitrogen atom to form a sulfonamide chloride (C 12 H 25 NH-SO2Cl). The -SO2CI group in the product C 12 H 25 NH-SO2Cl is a highly active derivative of sulfonic acid (-SO3H), which can be easily converted to the corresponding sulfonic acid by hydrolysis. The sulfonic acid group and the amino group are introduced into the sulfur bubble suppressant, and the specific reaction is as follows:

[0041] .

[0042] The second step is to add cetyltrimethylammonium bromide on the basis of the previous step. The essence is the ion exchange between the sulfonic acid and cetyltrimethylammonium bromide. The sulfonic acid provides a proton to form a sulfonate anion (C 12 H 25 NH-SO3 - ) and a hydrogen ion (H + ). The H + combines with Br - to form HBr. The sulfonate anion (C 12 H 25 NH-SO3 - ) combines with the cationic surfactant part of cetyltrimethylammonium bromide ([C 16 H 33 N(CH3)3] + ) through strong electrostatic attraction to form an ion pair. The quaternary ammonium group is introduced into the sulfur bubble suppressant to optimize the viscosity and stability of the liquid film, enhance the sulfur carrying capacity, and the specific reaction is as follows:

[0043] .

[0044] The third step is to add 2-mercaptoimidazole. The main reaction is the nucleophilic substitution of the thiol anion of 2-mercaptoimidazole on the quaternary ammonium cation, introducing the imidazole ring into the sulfur bubble suppressant, coordinating with sulfur, and increasing the sulfur suppression function. In this reaction process, the additive acetonitrile (acetonitrile can be added together with 2-mercaptoimidazole before the reaction, or slowly added during the reaction). The specific reaction is as follows:

[0045] .

[0046] Further, the application also provides application of the above-mentioned sulfur inhibiting foam agent in drainage gas recovery of high-temperature sour gas well. In actual application, the mass concentration of the above-mentioned sulfur inhibiting compound in the aqueous solution can be controlled to be 0.2% to 1.0%, preferably 0.2% to 0.5%. The amount is small, and the sulfur inhibiting foam agent can fully play its dual functions of sulfur inhibition and foam drainage, effectively solving the problems of sulfur deposition and wellbore / pipeline liquid accumulation in the gas well.

[0047] The application will be further described in conjunction with the specific embodiments. It should be noted that the embodiments described below or the technical features thereof can be combined to form new embodiments without conflict. The equipment and raw materials used can be purchased from the market or commonly used in the art. The methods in the following examples are conventional methods in the art unless otherwise specified.

[0048] First, the specific embodiments of the sulfur inhibiting foam agent and the preparation method thereof are as follows:

[0049] Example 1

[0050] The sulfur inhibiting foam agent of this example is made of the following components in percentage by weight: long-chain alkyl amine 30%, sulfonic acid compound 15%, quaternary ammonium salt 10%, imidazole ring compound 5%, auxiliary agent 5%, and the rest is water. The long-chain alkyl amine is dodecylamine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyltrimethylammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0051] The preparation method of the sulfur inhibiting foam agent of this example is as follows:

[0052] Using water as the basic reaction solvent, dodecylamine and chlorosulfonic acid are reacted at 0℃ for 2h under the protection of inert gas N2 to produce sulfonated products; then cetyltrimethylammonium bromide is added to the obtained sulfonated products, and reacted at 35℃ for 2h to generate amphoteric surfactants; finally, 2-mercaptoimidazole is added to the obtained amphoteric surfactants, and reacted at 35℃ for 3h, and acetonitrile solvent is slowly added in the process to obtain the sulfur inhibiting foam agent (the product appears as a light yellow transparent liquid).

[0053] Example 2

[0054] The sulfur inhibiting foam agent of this example is made of the following components in percentage by weight: long-chain alkyl amine 25%, sulfonic acid compound 20%, quaternary ammonium salt 12%, imidazole ring compound 3%, auxiliary agent 10%, and the rest is water. The long-chain alkyl amine is dodecylamine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyltrimethylammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0055] The preparation method of the sulfur inhibiting foam agent of this example is as follows:

[0056] The long chain alkyl amine is dodecyl amine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyl trimethyl ammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0057] Example 3

[0058] The sulfur foam inhibiting agent of this example is made of the following components in percentage by weight: long chain alkyl amine 35%, sulfonic acid compound 12%, quaternary ammonium salt 15%, imidazole ring compound 5%, auxiliary agent 10%, and the rest is water. The long chain alkyl amine is dodecyl amine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyl trimethyl ammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0059] The preparation method of the sulfur foam inhibiting agent of this example is as follows:

[0060] The long chain alkyl amine is dodecyl amine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyl trimethyl ammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0061] Example 4

[0062] The sulfur foam inhibiting agent of this example is made of the following components in percentage by weight: long chain alkyl amine 35%, sulfonic acid compound 12%, quaternary ammonium salt 15%, imidazole ring compound 5%, auxiliary agent 10%, and the rest is water. The long chain alkyl amine is dodecyl amine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyl trimethyl ammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0063] The preparation method of the sulfur foam inhibiting agent of this example is as follows:

[0064] The sulfonated product is produced by reacting dodecylamine with chlorosulfonic acid under the protection of inert gas N2 at 0°C for 2 hours using water as the basic reaction solvent; then adding cetyltrimethylammonium bromide to the obtained sulfonated product and reacting at 25°C for 1 hour to form an amphoteric surfactant; finally adding 2-mercaptoimidazole to the obtained amphoteric surfactant and reacting at 25°C for 2 hours, in the process, acetonitrile solvent is slowly added, to obtain the sulfur foam control agent (the product appears as a light yellow transparent liquid).

[0065] Example 5

[0066] The sulfur foam control agent of this example is made of the following components in percentage by weight: long chain alkyl amine 35%, sulfonic acid compound 12%, quaternary ammonium salt 15%, imidazole ring compound 5%, auxiliary agent 10%, and the rest is water. The long chain alkyl amine is dodecylamine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyltrimethylammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0067] The preparation method of the sulfur foam control agent of this example is as follows:

[0068] The sulfonated product is produced by reacting dodecylamine with chlorosulfonic acid under the protection of inert gas N2 at 5°C for 2.5 hours using water as the basic reaction solvent; then adding cetyltrimethylammonium bromide to the obtained sulfonated product and reacting at 40°C for 2 hours to form an amphoteric surfactant; finally adding 2-mercaptoimidazole to the obtained amphoteric surfactant and reacting at 40°C for 2 hours, in the process, acetonitrile solvent is slowly added, to obtain the sulfur foam control agent (the product appears as a light yellow transparent liquid).

[0069] Example 6

[0070] The sulfur foam control agent of this example is made of the following components in percentage by weight: long chain alkyl amine 35%, sulfonic acid compound 12%, quaternary ammonium salt 15%, imidazole ring compound 5%, auxiliary agent 10%, and the rest is water. The long chain alkyl amine is dodecylamine, the sulfonic acid compound is chlorosulfonic acid, the quaternary ammonium salt is cetyltrimethylammonium bromide, the imidazole ring compound is 2-mercaptoimidazole, and the auxiliary agent is acetonitrile.

[0071] The preparation method of the sulfur foam control agent of this example is as follows:

[0072] The sulfonated product is produced by reacting dodecylamine with chlorosulfonic acid under the protection of inert gas N2 at 3 DEG C for 2 hours, then adding cetyltrimethylammonium bromide to the obtained sulfonated product and reacting at 35 DEG C for 1.5 hours to form an amphoteric surfactant, and finally adding 2-mercaptoimidazole to the obtained amphoteric surfactant and reacting at 35 DEG C for 3 hours in the process of which acetonitrile solvent is slowly added to prepare the sulfur foam control agent (the product appears as a light yellow transparent liquid).

[0073] To verify the successful synthesis of the sulfur foam control agent, the final product is characterized by using a Fourier infrared characterization instrument, and the results are shown in the table. Figure 1 As shown in the table, 764 cm -1 is a (CH2) n in-plane rocking vibration absorption peak; 1060 cm -1 , 900 cm -1 are absorption characteristic peaks of S=O and S-O in the sulfonic acid group respectively; 1124 cm -1 and 3011 cm -1 are stretching vibration peaks of C-H; 1248 cm -1 is a stretching peak of C-N bond; 1648 cm -1 is an absorption peak of C=N; and 3391 cm -1 is a bending vibration absorption peak of N-H in the imidazole ring.

[0074] Secondly, the application of the sulfur foam control agent in the gas well drainage gas recovery is specifically as follows:

[0075] The key parameters involved in the following examples of the application are as follows:

[0076] Sulfur control rate (%) = (sulfur mass before experiment-sulfur mass after experiment) / sulfur mass before experiment x 100%;

[0077] Liquid carrying amount (mL) = (liquid volume before experiment-liquid volume after experiment);

[0078] Liquid carrying rate (%) = (liquid volume before experiment-liquid volume after experiment) / liquid volume before experiment.

[0079] Example 7: Performance test of the sulfur foam control agent

[0080] The sulfur control rate and the liquid carrying rate of the sulfur foam control agents in Examples 1-6 are detected in this example, and the specific implementation operation is as follows:

[0081] Sulfur inhibition performance test: first, take NaCl 70g, CaCl2 8g, MgCl2 2g, dissolved in 1L deionized water, prepared to simulate water with salinity of 80000mg / L, then add elemental sulfur powder to high salinity water, control the mass fraction of sulfur to 17%, ultrasonic dispersion for 30min to ensure uniform suspension of sulfur particles. According to the 0.5% mass concentration, the sulfur inhibition foam control agent prepared by examples 1~6 is added to the above sulfur-containing liquid, and the magnetic stirring is carried out for 0.5h to completely disperse. The gas-liquid multiphase pipe flow test device (flow chart is shown in Figure 2 The gas (nitrogen) injection rate (1m 3 / min), liquid injection rate (5L / min) is controlled, and the temperature control system is started to make the quartz tube segment stable at 130℃. During the test, the inlet pressure, temperature, gas and liquid flow rate and other parameters are recorded regularly to ensure stable experimental conditions. After 48 hours, the constant flow pump, gas injection and heating system are stopped in turn, and the device is naturally cooled to room temperature. The quartz tube segment is disassembled, and the solid material deposited on the inner wall of the quartz tube is collected using a scraper, distilled water washing and other methods. Finally, after filtration, drying and weighing, the total mass of the deposit is obtained, and the sulfur deposition inhibition rate (i.e. sulfur inhibition rate) is calculated. The results are shown in Table 1.

[0082] Table 1 Sulfur inhibition rate of sulfur inhibition foam control agent of examples 1~6

[0083]

[0084] Foam control performance test: first, take NaCl 70g, CaCl2 8g, MgCl2 2g, dissolved in 1L deionized water, prepared to simulate water with salinity of 80000mg / L, then take sulfur inhibition foam control agent with 0.5% mass concentration, respectively dissolved in 100mL (for foam performance test) and 200mL (for foam liquid carrying capacity test) simulated mineralized water, magnetic stirring for 30min to completely dissolve, room temperature standing for 30min for standby; when testing the foaming performance, the digital stirrer with calibrated speed is selected, 100mL of foam control agent solution is poured into a 250mL graduated beaker, the stirring paddle is adjusted to be immersed in the liquid surface by 1 / 2, the stirring is started (the speed is 6000rpm) at the same time the stopwatch is pressed, after 60 seconds the stirring is stopped, the line is parallel to the foam top to read the foam volume (unit: mL), each sample is tested for 3 times, the beaker and stirring paddle are cleaned and dried after each test, and the average value is taken as the foaming performance result; when testing the foam liquid carrying capacity, the Ross foam instrument is used, 200mL of foam control agent solution is poured into the foam instrument liquid storage pipe, the liquid storage pipe, foam generation pipe and graduated collection pipe are connected, the nitrogen valve is opened to make nitrogen flow in stably, and the time is counted for 15 minutes, after the experiment is finished, the volume of liquid carried in the graduated collection pipe is read (unit: mL). The test results are shown in Table 2.

[0085] Table 2: Test results of foam displacement performance of the sulfur inhibition foam displacement agents of Examples 1-6

[0086]

[0087] Example 8: Comparative experiment

[0088] The sulfur inhibition performance and foam displacement performance of the sulfur inhibition foam displacement agents of Examples 1-6 and the common foam displacement agents (not containing sulfur inhibition components, hereinafter referred to as Comparative Example 1) and the sulfur inhibitors (without foam displacement function, hereinafter referred to as Comparative Example 2) on the market were tested, and the specific implementation operations were as follows:

[0089] The specific process of the sulfur inhibition performance and foam displacement performance test was as described in Example 4, and the results are shown in Table 3.

[0090] Table 3: Performance comparison table

[0091]

[0092] As can be seen from the table, the single foam displacement agent has almost 0 sulfur deposition inhibition rate in the sulfur-containing environment, and the foam height and liquid carrying capacity are comparable to the product of the present application; the single sulfur removal agent can inhibit sulfur deposition to a certain extent, but has no foam displacement function and cannot solve the wellbore / pipeline liquid accumulation problem. The foam displacement agent of the present application can effectively inhibit sulfur deposition in the sulfur-containing, high-yield water natural gas well, and has good foam displacement performance, meeting the actual needs of gas well production.

[0093] When the chlorosulfonic acid in Example 1 is replaced by benzenesulfonic acid, or the dodecylamine is replaced by one of hexadecylamine and octadecylamine, or the cetyltrimethylammonium bromide is replaced by one of trimethylammonium chloride and tetrabutylammonium bromide, or the 2-mercaptoimidazole is replaced by imidazole, and the prepared sulfur inhibition foam displacement agent is subjected to performance evaluation according to the method of Example 7, it is found that the performance of the prepared sulfur inhibition foam displacement agent is consistent with that of the sulfur inhibition foam displacement agent of Example 1.

[0094] The above is only a preferred embodiment of the present application, and is not intended to limit the present application, and the patent protection scope of the present application is subject to the claims, and any equivalent structural changes made by using the content of the specification of the present application shall also be included in the protection scope of the present application.

Claims

1. A method for preparing a sulfur-inhibiting foaming agent, characterized in that: Includes the following steps: (1) Long-chain alkylamines react with sulfonic acid compounds in water under inert gas protection to produce sulfonated products; (2) Add a quaternary ammonium salt to the sulfonated product obtained in step (1) to generate an amphoteric surfactant; (3) The amphoteric surfactant obtained in step (2) and the imidazole ring compound are reacted to prepare a sulfur-suppressing foaming agent.

2. The method for preparing the sulfur-inhibiting foaming agent according to claim 1, characterized in that: The mass ratio of the long-chain alkylamine, sulfonic acid compound, quaternary ammonium salt and imidazole ring compound is (15~35):(10~25):(5~15):(1~5).

3. The method for preparing the sulfur-inhibiting foaming agent according to claim 2, characterized in that: The long-chain alkyl amine has a long-chain alkyl group of C12 to C18; the sulfonic acid compound is chlorosulfonic acid or benzenesulfonic acid.

4. The method for preparing the sulfur-inhibiting foaming agent according to claim 3, characterized in that: The long-chain alkylamine is one of dodecylamine, hexadecylamine, and octadecylamine.

5. The method for preparing the sulfur-inhibiting foaming agent according to any one of claims 1 to 4, characterized in that: The quaternary ammonium salt is one of trimethylammonium chloride, hexadecyltrimethylammonium bromide, and tetrabutylammonium bromide.

6. The method for preparing the sulfur-inhibiting foaming agent according to any one of claims 1 to 4, characterized in that: In step (3), acetonitrile is added during the reaction; the proportions of each raw material by weight percentage are as follows: long-chain alkylamine 15%~35%, sulfonic acid compound 10%~25%, quaternary ammonium salt 5%~15%, imidazole ring compound 1%~5%, acetonitrile 5%~10%, and the balance is water; the imidazole ring compound is imidazole or 2-mercaptoimidazole.

7. The method for preparing the sulfur-inhibiting foaming agent according to any one of claims 1 to 4, characterized in that: The reaction in step (1) is carried out at a temperature of 0-5℃ for 2-2.5 h.

8. The method for preparing the sulfur-inhibiting foaming agent according to any one of claims 1 to 4, characterized in that: The reaction in step (2) is carried out at a temperature of 25-40℃ for 1-2 hours.

9. The method for preparing the sulfur-inhibiting foaming agent according to any one of claims 1 to 4, characterized in that: The reaction in step (3) is carried out at a temperature of 25-40℃ for 2-4 hours.

10. A sulfur-inhibiting foam-draining agent prepared by the method of any one of claims 1 to 9.

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