Adjuvant for enhancing compatibility of bactericidal corrosion inhibitor, and bactericidal corrosion inhibitor

Abstract

Disclosed are an auxiliary agent for enhancing the compatibility of a bactericidal corrosion inhibitor, and a bactericidal corrosion inhibitor. The auxiliary agent comprises an ionic liquid and an alcohol compound in a mass ratio of 1-10:1-5; the ionic liquid comprises one or a combination multiple of of an imidazolium ionic liquid, a pyridinium ionic liquid, a quinoline ionic liquid, a quaternary ammonium salt ionic liquid and a quaternary phosphonium salt ionic liquid. The auxiliary agent provided by the present invention can enhance the compatibility of the bactericidal corrosion inhibitor with a flowback fluid. The bactericidal corrosion inhibitor of the present invention has the advantages of good high-temperature stability, no foaming, and high bactericidal and corrosion inhibition efficiency.

Description

Additives and bactericidal corrosion inhibitors for enhancing compatibility of bactericidal corrosion inhibitors Technical Field

[0001] The invention belongs to the technical field of oil and gas field development, and particularly relates to an additive and a bactericidal corrosion inhibitor for enhancing the compatibility of the bactericidal corrosion inhibitor. Background Art

[0002] In the production system of oil and gas field exploitation, the problem of component corrosion failure is becoming more and more frequent. In the production system of oil and gas fields, there is often corrosive gas CO2. Moreover, the exploitation of oil and gas fields generally adopts fracturing technology. The fracturing fluid contains a large amount of organic matter, which can provide nutrients for the growth of microorganisms, leading to the proliferation of microorganisms. At present, in the production system of oil and gas fields, the most harmful bacteria are sulfate-reducing bacteria (SRB), iron bacteria (IB) and saprophytic bacteria (TGB), etc., especially the coexistence and synergistic metabolism of multiple bacteria, which will cause more serious corrosion. In addition, the flowback fluid of the fracturing fluid has a high mineralization degree, Cl - Concentrations can exceed 10,000 mg / L. These corrosion factors lead to corrosion and perforation in both the wellbore and surface pipelines of production systems. This not only causes significant economic losses but also poses serious safety risks.

[0003] The main forms of corrosion in oil and gas field production systems include microbial corrosion and CO2 corrosion. Currently, biocides and corrosion inhibitors are widely used for corrosion control, primarily in combination. However, the composition of flowback fluid in production systems is complex, and the corrosion environments of the wellbore and surface pipelines vary significantly. Downhole temperatures can reach as high as 150°C, while surface pipeline temperatures are around 40°C. These environmental characteristics lead to the formation of insoluble substances such as flocculation and precipitation after the addition of chemicals. Especially at high downhole temperatures, chemicals at high temperatures are more likely to aggregate with suspended matter and sediment in the oil and gas field water, resulting in incompatibility. This incompatibility between chemicals and oil and gas field water increases the risk of well plugging. Furthermore, the performance of chemicals added to the wellbore and then flowed back into the surface pipeline is significantly reduced. Furthermore, produced water during the gathering and transportation process is prone to foaming due to airflow, which can cause air lock and reduce the efficiency of triethylene glycol in the dehydration unit. These characteristics pose significant challenges to chemical development. Therefore, in order to ensure the safe and efficient development of oil and gas fields, higher requirements are placed on the high-temperature and room-temperature compatibility, high-temperature stability and low-foaming performance of bactericidal corrosion inhibitors and flowback fluids.

[0004] At present, there are few reports on additives that enhance the compatibility of bactericidal corrosion inhibitors with flowback fluids. CN115613035A discloses a corrosion inhibitor compatibility method and application, and a corrosion inhibitor composition. The corrosion inhibitor compatibility method prepares an oil-soluble corrosion inhibitor into an O / W microemulsion system by adding a surfactant, an additive, and a hydrocarbon substance, thereby enhancing its compatibility in oil and gas field water. However, the method has many steps, and the added surfactant has strong foaming properties. CN114456148A discloses an oilfield corrosion inhibitor with good compatibility and a preparation method thereof. The preparation method of the corrosion inhibitor mainly prepares 6-(imidazolinyl)-2-pyridine carboxylate by reacting 2,6-pyridinedicarboxylic acid with polyethylene polyamine, and then undergoes a quaternization reaction with a chlorinated hydrocarbon to prepare an N-alkyl-6-(imidazolinyl)-2-pyridine carboxylate quaternary ammonium salt corrosion inhibitor. This corrosion inhibitor can be combined with commonly used oilfield water purifiers, scale inhibitors, demulsifiers, and fungicides, demonstrating excellent compatibility. CN112544624A discloses an environmentally friendly, integrated bactericidal corrosion inhibitor specifically designed for shale gas pipelines and its preparation method. The inhibitor is prepared using enrofloxacin and norfloxacin as bactericides, thiourea as a corrosion inhibitor, and ethanol or water as a solvent. However, the document does not mention research on the compatibility of the inhibitor at both room and high temperatures.

[0005] Therefore, developing methods to enhance the compatibility of bactericidal corrosion inhibitors and providing new bactericidal corrosion inhibitors that meet the needs of production systems are of great significance to corrosion control in oil and gas fields.

[0006] Summary of the Invention

[0007] To address the above technical problems, the present invention aims to provide an additive and a biocidal corrosion inhibitor that enhance the compatibility of a biocidal corrosion inhibitor. The additive provided by the present invention can enhance the compatibility of the biocidal corrosion inhibitor with flowback fluid. The biocidal corrosion inhibitor provided by the present invention has advantages such as good high-temperature stability and excellent biocidal and corrosion inhibition properties.

[0008] In order to achieve the above-mentioned object, the first aspect of the present invention provides an additive for enhancing the compatibility of a bactericidal corrosion inhibitor, comprising: an ionic liquid and an alcohol compound in a mass ratio of 1 to 10:1 to 5; wherein the ionic liquid comprises one or a combination of imidazole ionic liquids, pyridine ionic liquids, quinoline ionic liquids, quaternary ammonium salt ionic liquids and quaternary phosphonium salt ionic liquids;

[0009] The structural formula of the imidazole ionic liquid is shown in Formula I:

[0010] The structural formula of the pyridine ionic liquid is shown in Formula II:

[0011] The structural formula of the quinoline ionic liquid is shown in Formula III:

[0012] The structural formula of the quaternary ammonium salt ionic liquid is shown in Formula IV:

[0013] The structural formula of the quaternary phosphonium salt ionic liquid is shown in Formula V:

[0014] In Formula I, Formula II, Formula III, Formula IV and Formula V, R1, R2, R3, R4 and R5 are each independently selected from one of a C1-C4 straight-chain alkyl group, a C3-C4 branched-chain alkyl group, a C1-C4 alkoxy group, a C1-C4 alkanol group and a C2-C4 alkenyl group, and Z1 - Selected from HSO4 - 、NO3 - 、ClO4 - and CH3COO - One of them, Z2 - Selected from Cl - 、HSO4 - 、NO3 - 、ClO4 - and CH3COO - One of them.

[0015] In the aforementioned additives for enhancing the compatibility of the bactericidal corrosion inhibitor, preferably, the alcohol compound comprises a C1-C4 small molecule alcohol compound. More preferably, the alcohol compound comprises one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol.

[0016] The second aspect of the present invention provides a bactericidal corrosion inhibitor, which includes the following components, based on the total mass of the bactericidal corrosion inhibitor as 100%, 2 to 15% of the above-mentioned additive for enhancing the compatibility of the bactericidal corrosion inhibitor, 10 to 30% of a benzyl quaternary ammonium salt, 5 to 30% of a guanidine compound and / or glutaraldehyde, and the remainder of water.

[0017] According to a specific embodiment of the present invention, preferably, based on the total mass of the bactericidal corrosion inhibitor being 100%, the content of the ionic liquid is 1-10%, and the content of the alcohol compound is 1-5%.

[0018] In the above-mentioned bactericidal corrosion inhibitor, preferably, the benzyl-containing quaternary ammonium salt comprises a benzyl-containing aromatic heterocyclic quaternary ammonium salt compound. More preferably, the benzyl-containing quaternary ammonium salt comprises one or a combination of benzylquinoline quaternary ammonium salt, benzylpyridinium quaternary ammonium salt, benzylbenzothiazole quaternary ammonium salt, and benzylimidazole quaternary ammonium salt.

[0019] In the above-mentioned bactericidal corrosion inhibitor, preferably, the anion in the benzyl quaternary ammonium salt includes Cl - Br - , I -、HSO4 - 、NO3 - 、ClO4 - 、BF4 - PF6 - 、CH3COO - 、N(CN)2 - and SCN - One or a combination of the above.

[0020] In the above-mentioned bactericidal corrosion inhibitor, preferably, the guanidine compound includes one or a combination of polyhexamethylene monoguanidine salt, polyhexamethylene biguanidine salt, chlorhexidine and its salts.

[0021] In the above-mentioned bactericidal corrosion inhibitor, preferably, the structural formula of the polyhexamethylene guanidine salt is as shown in Formula X:

[0022] The structural formula of the polyhexamethylene biguanidine salt is shown in Formula XI:

[0023] The structure of the chlorhexidine is shown in Formula XII:

[0024] The structure of the salt of chlorhexidine is shown in Formula XIII:

[0025] In Formula X, Formula XI and Formula XIII, Y is selected from Cl - Br - , I - 、HSO4 - 、NO3 - 、C6H6-SO3 - 、ClO4 - 、CH3COO - 、N(CN)2 - 、SCN - 、CH3CH2COO - and CH2OH-(CHOH)4-COO - In Formula X and Formula XI, n is an integer of 5 to 100; in Formula XIII, m is an integer of 1 to 4.

[0026] According to a specific embodiment of the present invention, preferably, after the mixed systems obtained by mixing the bactericidal corrosion inhibitor with the fracturing flowback fluid are placed at 40° C. and 120° C. for 24 hours, the mixed systems are both homogeneous liquids.

[0027] According to a specific embodiment of the present invention, preferably, after the bactericidal corrosion inhibitor is placed at 40°C for 24 hours, under the condition of a usage amount of 100 mg / L, its bactericidal rate against SRB is more than 93.6%, the bactericidal rate against IB is more than 90.0%, and the bactericidal rate against TGB is more than 97.3%.

[0028] According to a specific embodiment of the present invention, preferably, after the bactericidal corrosion inhibitor is placed at 120° C. for 24 hours, under the condition of a usage amount of 100 mg / L, its bactericidal rate against SRB is more than 91.3%, the bactericidal rate against IB is more than 91.3%, and the bactericidal rate against TGB is more than 97.7%.

[0029] According to a specific embodiment of the present invention, preferably, the corrosion rate of the bactericidal corrosion inhibitor is below 0.076 mm / a.

[0030] According to a specific embodiment of the present invention, preferably, after 0.5 mL of the bactericidal corrosion inhibitor is mixed with 100 mL of fracturing flowback fluid and the resulting mixed system is stirred at a speed of 11000±200 r / min for 1 minute, the initial foam volume generated is less than 6 mL, and after standing for 3 minutes, the foam volume is 0 mL.

[0031] The present invention has at least the following beneficial effects:

[0032] The present invention provides an additive and a bactericidal corrosion inhibitor for enhancing the compatibility of a bactericidal corrosion inhibitor. The additive provided by the present invention can enhance the compatibility of the bactericidal corrosion inhibitor with flowback fluid, thereby increasing the adaptability of the bactericidal corrosion inhibitor in oil and gas field production systems. The bactericidal corrosion inhibitor provided by the present invention has good high-temperature stability, is non-foaming, has a good bactericidal effect on SRB, IB, and TGB, and exhibits excellent corrosion inhibition against CO2 corrosion. DETAILED DESCRIPTION

[0033] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the present invention is now described in detail below, but it should not be understood as limiting the scope of implementation of the present invention.

[0034] The present invention provides an additive for enhancing the compatibility of a bactericidal corrosion inhibitor, comprising: an ionic liquid and an alcohol compound in a mass ratio of 1 to 10:1 to 5; wherein the ionic liquid comprises one or a combination of several of an imidazole ionic liquid, a pyridine ionic liquid, a quinoline ionic liquid, a quaternary ammonium salt ionic liquid, and a quaternary phosphonium salt ionic liquid;

[0035] The structural formula of the imidazole ionic liquid is shown in Formula I:

[0036] The structural formula of the pyridine ionic liquid is shown in Formula II:

[0037] The structural formula of the quinoline ionic liquid is shown in Formula III:

[0038] The structural formula of the quaternary ammonium salt ionic liquid is shown in Formula IV:

[0039] The structural formula of the quaternary phosphonium salt ionic liquid is shown in Formula V:

[0040] In Formula I, Formula II, Formula III, Formula IV and Formula V, R1, R2, R3, R4 and R5 are each independently selected from one of a C1-C4 straight-chain alkyl group, a C3-C4 branched-chain alkyl group, a C1-C4 alkoxy group, a C1-C4 alkanol group and a C2-C4 alkenyl group, and Z1 - Selected from HSO4 - 、NO3 - 、ClO4 - and CH3COO - One of them, Z2 - Selected from Cl - 、HSO4 - 、NO3 - 、ClO4 - and CH3COO - Among them, in the present invention, the alkanol group can also be called a hydroxyalkyl group.

[0041] In some embodiments of the present invention, the alcohol compound includes a C1-C4 small molecule alcohol compound. Preferably, the alcohol compound includes one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol.

[0042] The auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor provided by the present invention includes an ionic liquid and an alcohol compound. The auxiliary agent mainly utilizes the dispersibility and solubilization effect of the anions and cations of the ionic liquid. On the one hand, it can promote the dissolution of the precipitate in the return fluid, and on the other hand, it can enhance the dispersibility of the bactericidal corrosion inhibitor in the return fluid, inhibit the flocculation and precipitation after its aggregation, and improve its compatibility. However, the inventors of this case have found through research that if the alkyl chain in the ionic liquid is too long (for example, an alkyl chain containing more than 5 carbon atoms), the solubility of the bactericidal corrosion inhibitor in the return fluid is too low, and the auxiliary agent does not have the effect of enhancing the compatibility of the bactericidal corrosion inhibitor with the return fluid. In addition, the inventors of this case also found that the type of anion has a greater influence on the effect of the ionic liquid on enhancing the compatibility. If the anion in the ionic liquid is SO4 2- 、H2PO4 - CF3SO3 - or C6H6-SO3- When the acid radical ions are equal, on the one hand, the bactericidal corrosion inhibitor is easy to react with Ba in the return fluid. 2+ or Ca 2+ Forming a precipitate, on the other hand, it can promote the aggregation and precipitation of insoluble matter. Therefore, the chemical structure of the ionic liquid has a great influence on the effect of the auxiliary agent on enhancing the compatibility of the bactericidal corrosion inhibitor with the return fluid. In addition, the auxiliary agent of the present invention contains an alcohol compound, which can further enhance the solubility of the bactericidal corrosion inhibitor in the return fluid. However, if the carbon chain length of the alcohol compound is too long (for example, a carbon chain containing more than 5 carbon atoms), it will also lead to the problem of low solubility of the bactericidal corrosion inhibitor in the return fluid. After a lot of research, the inventors of this case have developed an auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor of the present invention, which includes an ionic liquid with a specific chemical structure and a small molecule alcohol compound, which can significantly enhance the compatibility of the bactericidal corrosion inhibitor with the return fluid.

[0043] The present invention also provides a bactericidal corrosion inhibitor, which includes the following components, based on the total mass of the bactericidal corrosion inhibitor as 100%, 2 to 15% of the above-mentioned auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor, 10 to 30% of a benzyl quaternary ammonium salt, 5 to 30% of a guanidine compound and / or glutaraldehyde, and the remainder of water.

[0044] In some specific embodiments of the present invention, based on the total mass of the bactericidal corrosion inhibitor as 100%, it includes the following components: 1-10% ionic liquid, 1-5% alcohol compound, 10-30% benzyl quaternary ammonium salt, 5-30% guanidine compound and / or glutaraldehyde, and the balance water.

[0045] In some specific embodiments of the present invention, the benzyl-containing quaternary ammonium salt includes a benzyl-containing aromatic heterocyclic quaternary ammonium salt compound. Preferably, the benzyl-containing quaternary ammonium salt includes one or a combination of benzylquinoline quaternary ammonium salt, benzylpyridinium quaternary ammonium salt, benzylbenzothiazole quaternary ammonium salt and benzylimidazole quaternary ammonium salt.

[0046] In some embodiments of the present invention, the anion in the benzyl-containing quaternary ammonium salt includes Cl - Br - , I - 、HSO4 - 、NO3 - 、ClO4 - 、BF4 - PF6 - 、CH3COO - 、N(CN)2 - and SCN - One or a combination of the above.

[0047] Specifically, the structural formula of the benzylquinoline quaternary ammonium salt is shown in Formula VI:

[0048] The structural formula of the benzylpyridinium quaternary ammonium salt is shown in Formula VII:

[0049] The structural formula of the benzylbenzothiazole quaternary ammonium salt is shown in Formula VIII:

[0050] The structural formula of the benzyl imidazole quaternary ammonium salt is shown in Formula IX:

[0051] In Formulas VI, VII, VIII and IX, X - Selected from Cl - Br - , I - 、HSO4 - 、NO3 - 、ClO4 - 、BF4 - PF6 - 、CH3COO - 、N(CN)2 - and SCN - In formula IX, R is selected from one of C1~C4 straight-chain alkyl, C3~C4 branched-chain alkyl, C1~C4 alkoxy and C2~C4 alkenyl.

[0052] In some specific embodiments of the present invention, the guanidine compound includes one or a combination of polyhexamethylene monoguanidine salt, polyhexamethylene biguanidine salt, chlorhexidine and its salts.

[0053] Specifically, the structural formula of the polyhexamethylene guanidine salt is shown in Formula X:

[0054] The structural formula of the polyhexamethylene biguanidine salt is shown in Formula XI:

[0055] The structure of the chlorhexidine is shown in Formula XII:

[0056] The structure of the salt of chlorhexidine is shown in Formula XIII:

[0057] In Formula X, Formula XI and Formula XIII, Y is selected from Cl - Br - , I - 、HSO4 - 、NO3 - 、C6H6-SO3 - 、ClO4 -、CH3COO - 、N(CN)2 - 、SCN - 、CH3CH2COO - and CH2OH-(CHOH)4-COO - In Formula X and Formula XI, n is an integer of 5 to 100; in Formula XIII, m is an integer of 1 to 4.

[0058] In some specific embodiments of the present invention, the bactericidal corrosion inhibitor can be prepared by the following steps: at 25-40°C, according to the mass percentage of each component, a benzyl quaternary ammonium salt, a guanidine compound and / or glutaraldehyde, an ionic liquid, an alcohol compound and water are mixed, and stirred until the system is clear and transparent to obtain the bactericidal corrosion inhibitor.

[0059] In some specific embodiments of the present invention, after the mixed system obtained by mixing the bactericidal corrosion inhibitor with the fracturing flowback fluid is placed at 40°C and 120°C for 24 hours, the mixed system is a homogeneous liquid. Wherein, based on the total mass of the mixed system as 100%, the content of the bactericidal corrosion inhibitor is 10%, and the content of the fracturing flowback fluid is 90%. The total mineralization of the fracturing flowback fluid is greater than 6.58 g / L, for example, 6.58 g / L, 22.7 g / L, 25.1 g / L, 44.6 g / L, or 51.2 g / L.

[0060] In some specific embodiments of the present invention, after the bactericidal corrosion inhibitor is placed at 40°C for 24 hours, its bactericidal rate against SRB is greater than 93.6%, its bactericidal rate against IB is greater than 90.0%, and its bactericidal rate against TGB is greater than 97.3%. Specifically, after the mixed system obtained by mixing the bactericidal corrosion inhibitor with fracturing flowback fluid is placed at 40°C for 24 hours, the mixed system is subjected to a bactericidal test on a water sample containing SRB, IB, and TGB bacteria at a usage amount of 100 mg / L of the bactericidal corrosion inhibitor, thereby obtaining a bactericidal rate of greater than 93.6% against SRB, greater than 90.0% against IB, and greater than 97.3% against TGB. Wherein, based on the total mass of the mixed system as 100%, the content of the bactericidal corrosion inhibitor is 10%, and the content of the fracturing flowback fluid is 90%. The total salinity of the fracturing flowback fluid may be, for example, 22.7 g / L.

[0061] In some specific embodiments of the present invention, after being placed at 120°C for 24 hours, the bactericidal corrosion inhibitor has a bactericidal rate of 91.3% or more against SRB, 91.3% or more against IB, and 97.7% or more against TGB, at a usage amount of 100 mg / L. Specifically, after the mixed system obtained by mixing the bactericidal corrosion inhibitor with fracturing flowback fluid was placed at 120°C for 24 hours, the mixed system was subjected to a bactericidal test on a water sample containing SRB, IB, and TGB bacteria, at a usage amount of 100 mg / L of the bactericidal corrosion inhibitor. The results showed that the bactericidal corrosion inhibitor had a bactericidal rate of 91.3% or more against SRB, 91.3% or more against IB, and 97.7% or more against TGB. Based on the total mass of the mixed system as 100%, the content of the bactericidal corrosion inhibitor was 10%, and the content of the fracturing flowback fluid was 90%. The total salinity of the fracturing flowback fluid may be, for example, 22.7 g / L.

[0062] In some specific embodiments of the present invention, the corrosion rate of the bactericidal corrosion inhibitor is less than 0.076 mm / a. Specifically, after the mixed system obtained by mixing the bactericidal corrosion inhibitor with the fracturing flowback fluid is placed at 120°C for 24 hours, the mixed system is subjected to a corrosion test on a 5% NaCl water sample containing 800 ppm CO2 under the condition that the amount of the bactericidal corrosion inhibitor used is 1000 mg / L, and the corrosive material is L245N. After the corrosion test is carried out in an anaerobic environment at 60°C for 72 hours, the corrosion rate of the corrosive material (i.e., the corrosion rate of the bactericidal corrosion inhibitor) is less than 0.076 mm / a. Wherein, based on the total mass of the mixed system as 100%, the content of the bactericidal corrosion inhibitor is 10%, and the content of the fracturing flowback fluid is 90%. The total mineralization of the fracturing flowback fluid can be, for example, 22.7 g / L.

[0063] In some specific embodiments of the present invention, after 0.5 mL of the bactericidal corrosion inhibitor is mixed with 100 mL of fracturing flowback fluid and stirred at 11,000 ± 200 r / min for 1 minute, the resulting mixture produces an initial foam volume of less than 6 mL. After standing for 3 minutes, the foam volume is 0 mL. The total mineralization of the fracturing flowback fluid can be, for example, 22.7 g / L.

[0064] The bactericidal corrosion inhibitor of the present invention adopts a benzyl quaternary ammonium salt as a corrosion-inhibiting component, adopts a guanidine compound and / or glutaraldehyde as a bactericidal component, and adopts an auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor of the present invention, and uses water as a solvent to compound the bactericidal corrosion inhibitor. The auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor of the present invention, that is, the combination of an ionic liquid and an alcohol compound, can enhance the adaptability of the bactericidal corrosion inhibitor of the present invention in the production system of an oil and gas field (especially an unconventional gas field). In addition, the addition of an ionic liquid can enhance the bactericidal and corrosion-inhibiting performance of the bactericidal corrosion inhibitor to a certain extent, while the alcohol compound can enhance the bactericidal performance of the bactericidal corrosion inhibitor. The bactericidal corrosion inhibitor of the present invention has the advantages of good high-temperature stability, no foaming, high bactericidal and corrosion-inhibiting efficiency.

[0065] The present invention will be specifically described below with reference to Examples. However, the present invention is not limited to these Examples and can be implemented with various modifications within the scope of the gist of the present invention.

[0066] The raw materials used in the following examples and comparative examples include:

[0067] Benzylquinoline quaternary ammonium chloride: CAS: 15619-48-4, Aladdin Reagent Co., Ltd.

[0068] Benzylpyridinium quaternary ammonium chloride: CAS: 2876-13-3, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0069] Benzylpyridinium quaternary ammonium acetate: CAS: 58990-04-8, prepared in-house with reference to the description in The phytotoxicity of several S-benzyl-, S-phenacylisothiouronium, N-benzyl and N-phenacyltrimethylammonium N-benzyl-, and N-phenacylpyridinium alkanoates (Mededelingen van de Faculteit Landbouwwetenschappen, Universiteit Gent (1975), 40(2), 859-69);

[0070] Benzyl imidazole quaternary ammonium bromide: CAS: 65039-11-4, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0071] Benzyl imidazole quaternary ammonium hydrogen sulfate: CAS: 956597-95-8, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0072] Benzylbenzothiazole quaternary ammonium chloride (N-benzylbenzothiazole chloride): prepared in-house with reference to the description in Cyanine dyes, New potent antitumor agents (Chemical & Pharmaceutical Bulletin (1982), 30(9), 3106-20);

[0073] Polyhexamethyleneguanidine salt: CAS: 57028-96-3, Aladdin Reagent Co., Ltd.

[0074] Glutaraldehyde: 50% glutaraldehyde aqueous solution, Aladdin Reagent Co., Ltd.

[0075] Chlorhexidine: Sigma-Aldrich Reagent Company;

[0076] Chlorhexidine gluconate: Sigma-Aldrich Reagent Company;

[0077] 1-Ethyl-3-methylimidazolium hydrogen sulfate: CAS: 412009-61-1, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0078] Tetrakis (hydroxymethyl)phosphonium chloride: CAS: 124-64-1, Aladdin Reagent Co., Ltd.

[0079] 1-Ethylquinoline nitrate: prepared in-house with reference to the description in Corrosion inhibitors for steels in acids. II. Electrochemical kinetics of corrosion in the presence of inhibitors (Trudy Gosudarst. Inst. Priklad. Khim. (1960), No. 44, 39-64);

[0080] 1-Ethyl-3-methylimidazolium perchlorate: CAS: 665039-04-5, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0081] Tributylmethylammonium acetate: Sigma-Aldrich Reagent Company;

[0082] Isopropyl alcohol: Aladdin Reagent Co., Ltd.

[0083] Methanol: Aladdin Reagent Co., Ltd.;

[0084] Ethanol: Aladdin Reagent Co., Ltd.;

[0085] n-Propanol: Aladdin Reagent Co., Ltd.

[0086] n-Butanol: Aladdin Reagent Co., Ltd.;

[0087] Triethylhexyl ammonium bis(trifluoromethanesulfonyl)imide salt: CAS: 210230-46-9, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences;

[0088] Oleic acid imidazoline: MacLean Reagent Company.

[0089] Example 1

[0090] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0091] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylquinoline quaternary ammonium chloride, 30% of polyhexamethylene guanidine salt, 5% of 1-ethyl-3-methylimidazolium hydrogen sulfate, 5% of isopropyl alcohol and the remainder of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 1.

[0092] Example 2

[0093] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0094] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylquinoline quaternary ammonium chloride, 30% of polyhexamethylene guanidine salt, 7% of 1-ethyl-3-methylimidazole hydrogen sulfate, 5% of isopropyl alcohol and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 2.

[0095] Example 3

[0096] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0097] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylquinoline quaternary ammonium chloride, 30% of polyhexamethylene guanidine salt, 9% of 1-ethyl-3-methylimidazole hydrogen sulfate, 5% of isopropyl alcohol and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 3.

[0098] Example 4

[0099] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0100] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylpyridinium quaternary ammonium chloride, 10% of polyhexamethylene guanidine salt, 2% of tetrakis(hydroxymethyl)phosphonium chloride, 5% of methanol and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 4.

[0101] Example 5

[0102] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0103] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylpyridinium quaternary ammonium chloride, 10% of polyhexamethylene guanidine salt, 4% of tetrakis(hydroxymethyl)phosphonium chloride, 5% of methanol and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 5.

[0104] Example 6

[0105] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0106] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 30% of benzylpyridinium quaternary ammonium chloride, 10% of polyhexamethylene guanidine salt, 6% of tetrakishydroxymethylphosphonium chloride, 5% of methanol and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 6.

[0107] Example 7

[0108] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0109] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% benzylpyridinium quaternary ammonium acetate, 30% glutaraldehyde aqueous solution, 2% tetrakishydroxymethylphosphonium chloride, 5% isopropyl alcohol and the balance water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 7.

[0110] Example 8

[0111] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0112] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% benzylpyridinium quaternary ammonium acetate, 30% glutaraldehyde aqueous solution, 4% tetrakishydroxymethylphosphonium chloride, 5% isopropyl alcohol and the balance water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 8.

[0113] Example 9

[0114] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0115] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% benzylpyridinium quaternary ammonium acetate, 30% glutaraldehyde aqueous solution, 6% tetrakishydroxymethylphosphonium chloride, 5% isopropyl alcohol and the balance water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 9.

[0116] Example 10

[0117] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0118] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% of benzyl imidazole quaternary ammonium bromide, 10% of chlorhexidine, 5% of 1-ethylquinoline nitrate, 5% of ethanol, and the remainder of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 10.

[0119] Example 11

[0120] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0121] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% of benzyl imidazole quaternary ammonium hydrogen sulfate, 20% of chlorhexidine gluconate, 5% of 1-ethyl-3-methylimidazole perchlorate, 5% of n-propanol, and the balance of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 11.

[0122] Example 12

[0123] This embodiment provides a bactericidal corrosion inhibitor, which is prepared by the following steps:

[0124] At 25-40° C., based on the total mass of the bactericidal corrosion inhibitor as 100%, 10% of benzylbenzothiazole quaternary ammonium chloride, 20% of glutaraldehyde aqueous solution, 5% of tributyl methylammonium acetate, 5% of n-butanol and the remainder of water were mixed and stirred until the system became clear and transparent to obtain a bactericidal corrosion inhibitor, which was recorded as No. 12.

[0125] Comparative Example 1

[0126] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor being 100%, comprises the following components: 30% benzylquinoline quaternary ammonium chloride, 30% polyhexamethylene guanidine salt, and the balance water, denoted as A, for comparison with Examples 1 to 3. The preparation method of the fungicide corrosion inhibitor is the same as that of the above examples.

[0127] Comparative Example 2

[0128] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor being 100%, comprises the following components: 30% benzylpyridinium quaternary ammonium chloride, 10% polyhexamethylene guanidine salt, and the balance water, denoted as B, for comparison with Examples 4 to 6. The preparation method of the fungicide corrosion inhibitor is the same as that of the above examples.

[0129] Comparative Example 3

[0130] This comparative example provides a fungicide corrosion inhibitor comprising the following components, based on the total mass of the fungicide corrosion inhibitor as 100%, 10% benzylpyridinium quaternary ammonium acetate, 30% glutaraldehyde aqueous solution, and the balance water (denoted as C), for comparison with Examples 7 to 9. The preparation method of the fungicide corrosion inhibitor is the same as that of the above examples.

[0131] Comparative Example 4

[0132] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor as 100%, comprises the following components: 10% benzylpyridinium quaternary ammonium acetate, 30% glutaraldehyde aqueous solution, 5% triethylhexylammonium bis(trifluoromethanesulfonyl)imide salt, 5% isopropyl alcohol, and the balance water, denoted as D, for comparison with Examples 7 to 9. The preparation method of the fungicide corrosion inhibitor is the same as that of the above examples.

[0133] Comparative Example 5

[0134] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor as 100%, comprises the following components: 30% benzylquinoline quaternary ammonium chloride, 30% polyhexamethylene guanidine salt, 5% 1-ethyl-3-methylimidazolium hydrogen sulfate, and the balance water, denoted as E, for comparison with Example 1. The preparation method of the fungicide corrosion inhibitor is the same as that of the above example.

[0135] Comparative Example 6

[0136] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor as 100%, comprises the following components: 30% oleic acid imidazoline, 30% polyhexamethylene monoguanidine salt, 5% 1-ethyl-3-methylimidazolium hydrogen sulfate, 5% isopropyl alcohol, and the balance water, denoted as F, for comparison with Example 1. The preparation method of the fungicide corrosion inhibitor is the same as that of the above example.

[0137] Comparative Example 7

[0138] This comparative example provides a fungicide corrosion inhibitor, which, based on the total mass of the fungicide corrosion inhibitor as 100%, comprises the following components: 5% benzylpyridinium quaternary ammonium chloride, 40% polyhexamethylene monoguanidine salt, 0.5% tetrakishydroxymethylphosphonium chloride, 10% methanol, and the balance water, denoted as G, for comparison with Examples 4 to 6. The preparation method of the fungicide corrosion inhibitor is the same as that of the above examples.

[0139] Test Example 1

[0140] This test example evaluated the compatibility of the bactericidal corrosion inhibitors provided in Examples 1 to 12 and Comparative Examples 1 to 7 with the fracturing flowback fluid.

[0141] The specific evaluation process is as follows: referring to the compatibility evaluation method in the standard SY / T 7437-2019 "Technical Requirements and Evaluation Methods for Corrosion Inhibitors for Natural Gas Gathering and Transportation", the bactericidal corrosion inhibitor is added to the fracturing return fluid of unconventional gas wells. The total mass of the fracturing return fluid after the addition of the bactericidal corrosion inhibitor is 100%, and the amount of bactericidal corrosion inhibitor added is 10%. Then, it is placed at 40°C and 120°C for 24 hours respectively to observe the compatibility of the bactericidal corrosion inhibitor and the field return fluid.

[0142] The evaluation results are shown in Tables 1, 2 and 3.

[0143] Table 1

[0144] In Table 1, the solubility (mg / L) of each ion in the flowback fluid of a well in the tight gas field is: Na + 89700, K + 162.Mg 2+ 35.0, Ca 2+ 348、SO4 2- 5.56, HCO3 - 595、Cl - 11700, total mineralization is 22.7 g / L.

[0145] Table 2

[0146] In Table 2, the solubility (mg / L) of each ion in the flowback fluid of a well in the shale gas field is: Na + 1330, K + 45.Mg 2+ 82. Ca 2+ 139. HCO3 - 128、Cl - 3000、Sr 2+ 4.6, and the total mineralization is 6.58g / L.

[0147] Table 3

[0148] In Table 3, the solubility (mg / L) of each ion in the water sample is: Na + 89700, K + 162.Mg 2+ 35.0, Ca 2+ 348、SO4 2- 5.56, HCO3 - 595、Cl - 11700, total mineralization is 22.7 g / L.

[0149] The solubility of each ion in the water sample 2 (mg / L) is: Na + 12300、Fe 2+ 11.4, K + 136.Mg 2+ 143、Ca 2+ 596、HCO3 - 138、Cl - 23400、Sr 2+ 8.9, and the total mineralization is 37.7 g / L.

[0150] The solubility of each ion in the water sample 3 (mg / L) is: Na + 16200、Fe 2+ 10.5, K + 158.Mg 2+ 193、Ca 2+ 941, HCO3 - 144、Cl - 31100、Sr 2+ 8.7 SO4 2- 11.6, and the total mineralization is 51.2 g / L.

[0151] The solubility (mg / L) of each ion in the water sample 4 is: Na + 13800、Fe 2+ 9.84, K + 132.Mg 2+ 220、Ca 2+ 958, HCO3 - 142、Cl - 27500、Sr 2+ 6.9 SO4 2- 10.5, and the total mineralization is 44.6 g / L.

[0152] The solubility of each ion in the water sample 5 (mg / L) is: Na + 874000、Fe 2+ 12.4, K+ 158.Mg 2+ 106、Ca 2+ 442, HCO3 - 289、Cl - 14600、Sr 2+ 7.8 SO4 2- 22.1, and the total mineralization is 25.1 g / L.

[0153] As can be seen from Tables 1, 2 and 3, under the conditions of 40°C and 120°C, the compatibility of the bactericidal corrosion inhibitors No. 1-12 provided in Examples 1 to 12 containing ionic liquids and alcohol compounds with the flowback fluids of different unconventional gas wells is significantly improved compared to the A, B and C type bactericidal corrosion inhibitors provided in Comparative Examples 1 to 3 that do not contain ionic liquids and alcohol compounds. This shows that the adjuvant of the present invention can effectively improve the compatibility of the bactericidal corrosion inhibitor with the flowback fluid. However, from the compatibility results of the D-G type bactericidal corrosion inhibitors provided in Comparative Examples 4 to 7 with the flowback fluid, it can be seen that changing the carbon chain length or anion of the ionic liquid, not adding the alcohol compound, or changing the ratio of the ionic liquid and the alcohol compound in the adjuvants of Comparative Examples 4 to 7 all make the compatibility of the bactericidal corrosion inhibitor unable to achieve the excellent effects of the embodiments of the present invention.

[0154] Test Example 2

[0155] This test example evaluated the bactericidal performance of the bactericidal corrosion inhibitors provided in Examples 1 to 12 and Comparative Examples 1 to 7.

[0156] The specific evaluation process is as follows: bactericidal corrosion inhibitors No. 1-12 and A-G are added to the fracturing flowback fluid of a well in a shale gas field at a dosage of 10% (based on the total mass of the fracturing flowback fluid after adding the bactericidal corrosion inhibitor as 100%), and then placed at 40°C and 120°C for 24 hours respectively. The flowback fluid containing the bactericidal corrosion inhibitor is taken and added to a water sample containing SRB, IB and TGB bacteria at a dosage of 100 mg / L of bactericidal corrosion inhibitor to conduct a bactericidal test. Among them, the solubility (mg / L) of each ion in the fracturing flowback fluid of a well in the shale gas field is: Na + 89700, K + 162.Mg 2+ 35.0, Ca 2+ 348、SO4 2- 5.56, HCO3 - 595、Cl - 11700, total mineralization is 22.7 g / L.

[0157] Sterilization test method: After adding flowback fluid containing bactericidal corrosion inhibitor to the water sample containing bacteria, incubate in an oxygen-free environment at 25°C for 24 hours, refer to the standard SY / T 0532-2012 "Oilfield Injection Water Bacterial Analysis Method (Extinction Dilution Method)" to determine the bacterial content in the water sample and calculate the sterilization rate. The sterilization rate calculation formula is as follows:

[0158] Where: X is the sterilization rate (%); a2 is the number of bacteria after sterilization (cells / mL); a1 is the number of blank bacteria (cells / mL).

[0159] The sterilization rate results are shown in Table 4.

[0160] Table 4

[0161] As can be seen from Table 4, after the mixture of the bactericidal corrosion inhibitors No. 1-12 provided in Examples 1 to 12 and the flowback fluid of the shale gas well is placed at 40°C for 24 hours, under the condition that the bactericidal corrosion inhibitor content is 100 ppm, the bactericidal rate for SRB is as low as 93.6% and as high as 100.0%, the bactericidal rate for IB is as low as 90.0% and as high as 100.0%, and the bactericidal rate for TGB is as low as 97.3% and as high as 100.0%. After the mixture of bactericidal corrosion inhibitors No. 1-12 provided in Examples 1 to 12 and shale gas well flowback fluid was placed at 120°C for 24 hours, the sterilization rate against SRB was as low as 91.3% and as high as 100.0%, the sterilization rate against IB was as low as 91.3% and as high as 100.0%, and the sterilization rate against TGB was as low as 97.7% and as high as 100.0%. Therefore, the bactericidal corrosion inhibitors prepared in Examples 1 to 12 have good bactericidal properties and good high-temperature stability. After being placed at 120°C, the sterilization rates of the bactericidal corrosion inhibitors against SRB, IB, and TGB were essentially unchanged from those after being placed at 40°C. After being placed at 40°C and 120°C for 24 hours, the bactericidal efficacy of bactericidal inhibitors A, B, C, and F against the three bacteria was below 85%, and their bactericidal efficacy decreased to a certain extent at high temperatures. This is because after mixing with the on-site water, some of the inhibitors were precipitated, resulting in a reduction in the dosage of the drug in the solution, thus weakening the bactericidal efficacy. While bactericidal inhibitors D, E, and G had a bactericidal efficacy of over 90% against the three bacteria at room temperature, their bactericidal efficacy was also greatly weakened at high temperatures. This is related to their poor compatibility at high temperatures and the reduction in the dosage of the drug in the solution.

[0162] Test Example 3

[0163] This test example evaluated the corrosion inhibition performance of the bactericidal corrosion inhibitors provided in Examples 1 to 12 and Comparative Examples 1 to 7.

[0164] The specific evaluation process is as follows: bactericidal corrosion inhibitors No. 1-12 and A to G are added at a dosage of 10% (based on the total mass of the fracturing flowback fluid after adding the bactericidal corrosion inhibitor as 100%) to the fracturing flowback fluid of a well in a shale gas field (the same as in Test Example 2), and then placed at 120°C for 24 hours. The flowback fluid containing the bactericidal corrosion inhibitor is taken and a corrosion test is carried out on a 5% NaCl water sample containing 800ppm CO2 at a bactericidal corrosion inhibitor addition dosage of 1000mg / L. The corroded material is L245N. After being placed in an anaerobic environment at 60°C for 72 hours, the corrosion rate is calculated with reference to the standard SY / T 7437-2019 "Technical Requirements and Evaluation Methods for Corrosion Inhibitors for Natural Gas Gathering and Transportation". The corrosion rate calculation formula is as follows:

[0165] Where: V is the uniform corrosion rate, millimeters per year (mm / a); m is the weight loss of the specimen, grams (g); s is the exposed area of ​​the specimen, square centimeters (cm 2 ); t—experimental time, hours (h); ρ—relative density of the specimen, grams per cubic centimeter (g / cm 3 ).

[0166] The corrosion rate results are shown in Table 5.

[0167] Table 5

[0168] As can be seen from Table 5, the corrosion rates of the bactericidal corrosion inhibitors No. 1-12 provided in Examples 1 to 12 after being placed at 120°C for 24 hours are all below 0.076 mm / a. It can be seen that the bactericidal corrosion inhibitors provided in Examples 1 to 12 have good corrosion inhibition performance. From the results of the comparative examples, the corrosion rates of the comparative examples are all above 0.076 mm / a. The poor compatibility of the bactericidal corrosion inhibitor will affect its effective use concentration in the solution, so that the corrosion rate does not meet the current application requirements. The adjuvant of the present invention improves the compatibility of the bactericidal corrosion inhibitor in on-site water and enhances its on-site applicability in unconventional gas fields.

[0169] Test Example 4

[0170] This test example evaluated the foaming performance of the bactericidal corrosion inhibitors provided in Examples 1 to 12 and Comparative Examples 1 to 7.

[0171] The specific evaluation process was as follows: Referring to the method in standard Q / SY 16859-2020, "Technical Specification for Foam Drainage Processing in Shale Gas Wells," 100 mL of fracturing flowback fluid from a shale gas well (the same as in Test Example 2) was taken, 0.5 mL of bactericidal corrosion inhibitors Nos. 1-12 and A-G were added, respectively. After stirring for 1 minute using a high-speed blender at 11,000 ± 200 rpm, the mixture was immediately poured into a 200 mL graduated cylinder. The initial volume of the foam layer and the volume after standing for 3 minutes were recorded. This process was repeated three or more times. The average of the three test results is shown in Table 6.

[0172] Table 6

[0173] As can be seen from Table 6, when the bactericidal corrosion inhibitors No. 1-12 provided in Examples 1 to 12 are added to the water samples of the unconventional gas well field return fluid, the initial foam volume is less than 6 mL, and the foam completely disappears after standing for 3 minutes. It can be seen that the bactericidal corrosion inhibitors provided in Examples 1 to 12 are basically not foaming when added to the field return fluid, which can meet the requirements of field applications. However, the bactericidal corrosion inhibitors A, B, and C types without the addition of additives have a foam volume of 20 to 45 mL in 1 minute. In addition, the bactericidal corrosion inhibitor D adds an ionic liquid with a longer carbon chain and the type F uses an oleic acid imidazoline corrosion inhibitor. Their foam volume is large and does not meet the requirements of field applications. No alcohol additive is added to the bactericidal corrosion inhibitor type E, and its initial foam volume is slightly larger.

[0174] In summary, the auxiliary agent provided by the present invention can enhance the compatibility of the bactericidal corrosion inhibitor with the backflow liquid. By controlling the type of auxiliary agent such as the carbon chain length of the ionic liquid, the type of anion, and the type of alcohol compound, and the ratio of each component in the bactericidal corrosion inhibitor, etc. within the scope of the present invention, the bactericidal corrosion inhibitor of the present invention has good adaptability and application in the production system of oil and gas fields (especially unconventional gas fields). The bactericidal corrosion inhibitor provided by the present invention has good high temperature stability, does not foam, has good bactericidal effect on SRB, IB and TGB, and has good corrosion inhibition effect on CO2 corrosion.

[0175] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not limitations on the implementation methods of the present invention. For ordinary technicians in the relevant field, other different forms of changes or modifications can be made based on the above description. It is impossible to list all the implementation methods here. All obvious changes or modifications derived from the technical solution of the present invention are still within the scope of protection of the present invention.

Claims

1. An additive for enhancing the compatibility of a bactericidal corrosion inhibitor, comprising: An ionic liquid and an alcohol compound in a mass ratio of 1 to 10:1 to 5; wherein the ionic liquid comprises one or a combination of imidazole ionic liquids, pyridine ionic liquids, quinoline ionic liquids, quaternary ammonium salt ionic liquids and quaternary phosphonium salt ionic liquids; The structural formula of the imidazole ionic liquid is shown in Formula I: The structural formula of the pyridine ionic liquid is shown in Formula II: The structural formula of the quinoline ionic liquid is shown in Formula III: The structural formula of the quaternary ammonium salt ionic liquid is shown in Formula IV: The structural formula of the quaternary phosphonium salt ionic liquid is shown in Formula V: In Formula I, Formula II, Formula III, Formula IV and Formula V, R1, R2, R3, R4 and R5 are each independently selected from one of a C1-C4 straight-chain alkyl group, a C3-C4 branched-chain alkyl group, a C1-C4 alkoxy group, a C1-C4 alkanol group and a C2-C4 alkenyl group, and Z1 - Selected from HSO4 - 、NO3 - 、ClO4 - and CH3COO - One of them, Z2 - Selected from Cl - 、HSO4 - 、NO3 - 、ClO4 - and CH3COO - One of them.

2. The auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor according to claim 1, wherein: The alcohol compounds include small molecule alcohol compounds of C1 to C4.

3. The auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor according to claim 2, wherein: The alcohol compound includes one or a combination of methanol, ethanol, n-propanol, isopropanol, n-butanol and tert-butanol.

4. A bactericidal corrosion inhibitor, wherein: Taking the total mass of the bactericidal corrosion inhibitor as 100%, The invention comprises the following components: 2-15% of the auxiliary agent for enhancing the compatibility of the bactericidal corrosion inhibitor as claimed in any one of claims 1 to 3, 10-30% of benzyl quaternary ammonium salt, 5-30% of guanidine compound and / or glutaraldehyde, and the remainder of water.

5. The bactericidal corrosion inhibitor according to claim 4, wherein Taking the total mass of the bactericidal corrosion inhibitor as 100%, the content of the ionic liquid is 1-10%, and the content of the alcohol compound is 1-5%.

6. The bactericidal corrosion inhibitor according to claim 4, wherein The benzyl-containing quaternary ammonium salt includes benzyl-containing aromatic heterocyclic quaternary ammonium salt compounds.

7. The bactericidal corrosion inhibitor according to claim 6, wherein The benzyl-containing quaternary ammonium salt includes one or a combination of benzylquinoline quaternary ammonium salt, benzylpyridinium quaternary ammonium salt, benzylbenzothiazole quaternary ammonium salt and benzylimidazole quaternary ammonium salt.

8. The bactericidal corrosion inhibitor according to claim 6, wherein The anion in the benzyl quaternary ammonium salt includes Cl - Br - ,I - 、HSO4 - 、NO3 - 、ClO4 - 、BF4 - PF6 - 、CH3COO - 、N(CN)2 - and SCN - One or a combination of the following.

9. The bactericidal corrosion inhibitor according to claim 4, wherein: The guanidine compound includes one or a combination of polyhexamethylene monoguanidine salt, polyhexamethylene biguanidine salt, and chlorhexidine and its salts.

10. The bactericidal corrosion inhibitor according to claim 9, wherein The structural formula of the polyhexamethylene guanidine salt is shown in Formula X: The structural formula of the polyhexamethylene biguanide salt is shown in Formula XI: The structure of the chlorhexidine is shown in Formula XII: The structure of the salt of chlorhexidine is shown in Formula XIII: In Formula X, Formula XI and Formula XIII, Y is selected from Cl - Br - ,I - 、HSO4 - 、NO3 - 、C6H6-SO3 - 、ClO4 - 、CH3COO - 、N(CN)2 - 、SCN - 、CH3CH2COO - and CH2OH-(CHOH)4-COO - In Formula X and Formula XI, n is an integer of 5 to 100; in Formula XIII, m is an integer of 1 to 4.

11. The bactericidal corrosion inhibitor according to claim 4, wherein: After the mixed systems obtained by mixing the bactericidal corrosion inhibitor with the fracturing flowback fluid were placed at 40° C. and 120° C. for 24 hours, the mixed systems were all homogeneous liquids.

12. The bactericidal corrosion inhibitor according to claim 4, wherein: After being placed at 40° C. for 24 hours, the bactericidal corrosion inhibitor has a bactericidal rate of more than 93.6% for SRB, more than 90.0% for IB, and more than 97.3% for TGB when used in an amount of 100 mg / L.

13. The bactericidal corrosion inhibitor according to claim 4, wherein: After being placed at 120° C. for 24 hours, the bactericidal corrosion inhibitor has a bactericidal rate of more than 91.3% for SRB, more than 91.3% for IB, and more than 97.7% for TGB when used in an amount of 100 mg / L.

14. The bactericidal corrosion inhibitor according to claim 4, wherein: The corrosion rate of the bactericidal corrosion inhibitor is below 0.076 mm / a.

15. The bactericidal corrosion inhibitor according to claim 4, wherein: After 0.5 mL of the bactericidal corrosion inhibitor was mixed with 100 mL of fracturing flowback fluid and the resulting mixed system was stirred at a speed of 11000±200 r / min for 1 min, the initial foam volume generated was less than 6 mL, and after standing for 3 min, the foam volume was 0 mL.

Images