Mannich base quaternary ammonium salt compound, preparation method thereof, acidizing corrosion inhibitor, acid liquid and application thereof

Abstract

The application relates to the field of oil and gas development, and discloses a Mannich base quaternary ammonium salt compound, a preparation method of the compound, an acid corrosion inhibitor, acid liquid and application of the acid liquid. The compound has the structure shown in formula (1): wherein R1 and R2 are each independently selected from hydrogen, C1-C5 linear alkyl and C3-C5 branched alkyl; and X is selected from one or more of F, Cl and Br. The corrosion inhibitor system has high temperature resistance and excellent corrosion inhibition performance, so that the corrosion resistance of oil and gas exploitation equipment can be improved, and the safety, stability and efficiency of the oil and gas exploitation process can be improved.

Description

Technical Field

[0001] This invention belongs to the field of oil and gas development, specifically relating to a Mannich base quaternary ammonium salt compound and its preparation method, an acidification corrosion inhibitor, an acid solution and its application. Background Technology

[0002] In the process of oil exploration and development, as extraction progresses, the extraction environment becomes increasingly complex, and extraction efficiency decreases. Oil and gas well acidizing can significantly improve oil and gas recovery rates. Oil well acidizing technology uses acid to dissolve blockages in rocks and permeable channels or formation fractures, thereby expanding oil flow channels, reducing oil flow resistance, increasing the permeability of oil and gas reservoir rocks, and increasing oil production.

[0003] However, during the acidizing process of the well, the acid system inevitably causes a certain degree of corrosion to the production equipment and metal pipelines along the pipeline. Furthermore, with increasing well depth and rising bottom-hole temperature (some wells even reach 190°C), the corrosion caused by the acid system to the metal increases exponentially. To address the corrosion protection problem of the acidizing fluid on oil well casing equipment, adding an acidizing corrosion inhibitor to the system is currently the most economical and effective method.

[0004] Currently, organic corrosion inhibitors are commonly used in acidizing processes, mainly including heteroatom compounds such as Mannich bases, amides, imidazolines, pyridine, and quinoline quaternary ammonium salts. However, there are few corrosion inhibitors on the market that can meet the requirements of high-temperature acidizing. High temperatures significantly reduce the corrosion inhibition ability of conventional corrosion inhibitors for metal equipment. In addition, conventional corrosion inhibitors are prone to decomposition at high temperatures, losing their corrosion inhibition properties, and also have the disadvantages of unstable performance such as coking and delamination at high temperatures, which may cause formation damage.

[0005] CN109294549A discloses a high-temperature oilfield acidizing corrosion inhibitor and its preparation method. This high-temperature oilfield acidizing corrosion inhibitor comprises the following components in parts by weight: 30-60 parts Mannich base, 40-60 parts propylene glycol, 5-10 parts octadecyltrimethylammonium chloride, and 0.5-2 parts antimony trioxide. This technical solution uses propynyl alcohol as a reaction raw material; however, this substance is a flammable and highly toxic liquid, and due to safety considerations, this technical solution is not suitable for widespread application.

[0006] CN109355663A discloses a corrosion inhibitor for oilfields, its preparation method, and its application. The corrosion inhibitor comprises 50-100 parts oleic acid, 20-40 parts diethylenetriamine, 80-120 parts ethylene oxide, a suitable catalyst, 100-200 parts dispersant, and 600-700 parts water. This technical solution uses a strong imidazoline quaternary ammonium salt as the main component, and incorporates alcohols, highly efficient penetrants, surfactants, etc., to form a corrosion inhibitor with strong targeting of produced water. However, this corrosion inhibitor is not suitable for use in high-temperature environments.

[0007] CN110079807A discloses an oilfield scale inhibitor and corrosion inhibitor suitable for high temperatures and its preparation method. However, this scale inhibitor and corrosion inhibitor is only suitable for high-temperature environments of 70°C to prevent corrosion caused by low acidity, high salinity, CO2 and H2S and high temperature, but no guidance is given on its adaptability to temperature conditions above 160°C.

[0008] Therefore, developing a new type of corrosion inhibitor that is both heat-resistant and has excellent corrosion inhibition properties is not only beneficial to improving the corrosion resistance of oil and gas extraction equipment, but also of great significance to improving the safe, stable and efficient operation of the oil and gas extraction process. Summary of the Invention

[0009] The purpose of this invention is to overcome the problem that existing corrosion inhibitors have poor corrosion inhibition performance at high temperatures, and to provide a Mannich base quaternary ammonium salt compound and its preparation method, an acidification corrosion inhibitor, an acid solution and its application.

[0010] To achieve the above objectives, a first aspect of the present invention provides a Mannich base quaternary ammonium salt compound, wherein the compound has the structure shown in formula (1):

[0011]

[0012] R1 and R2 are each independently selected from hydrogen, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, C1-C5 alkoxy or hydroxy-substituted C1-C5 alkyl; X is selected from one or more of F, Cl and Br.

[0013] A second aspect of the present invention provides a method for preparing a Mannich base quaternary ammonium salt compound, comprising the following steps:

[0014] 1) Formaldehyde, compound A, solvent and concentrated hydrochloric acid are mixed and subjected to the first reaction to obtain the product;

[0015] 2) The product is reacted with compound B in a second reaction to obtain Mannich base compounds;

[0016] 3) The Mannich base compound is reacted with compound C in a third reaction and then distilled under reduced pressure to obtain the Mannich base quaternary ammonium salt compound;

[0017] Compound A has the structure shown in formula (2): Compound B has the structure shown in formula (3): Compound C has the structure shown in formula (4): Where X is selected from F, Cl or Br; the definitions of R1 and R2 are the same as those in the first aspect.

[0018] A third aspect of the present invention provides an acid corrosion inhibitor, wherein, based on the total amount of the acid corrosion inhibitor, the acid corrosion inhibitor comprises: 15-40 wt% of a Mannich base quaternary ammonium salt compound, 15-40 wt% of a dichlorobenzyl bisquinoline quaternary ammonium salt, 3-15 wt% of potassium iodide, 5-30 wt% of a phenacetin compound, 5-20 wt% of an alkynyl alcohol compound, 2-15 wt% of an antimony salt, and 2-40 wt% of a saturated alcohol compound.

[0019] A fourth aspect of the present invention provides an acid solution comprising: an amino acid; and the aforementioned acidification and corrosion inhibitor.

[0020] The fifth aspect of the present invention provides the application of the aforementioned acid solution in high-temperature reservoir oil and gas extraction.

[0021] The beneficial technical effects achieved by the present invention through the above technical solution are as follows:

[0022] This invention provides an acidizing corrosion inhibitor composed of specific components in specific amounts, suitable for acidizing oil and gas channels in high-temperature reservoirs at 160-180℃. The corrosion inhibitor system of this invention is both high-temperature resistant and possesses excellent corrosion inhibition properties, thereby improving the corrosion resistance of oil and gas extraction equipment and contributing to a safer, more stable, and more efficient oil and gas extraction process. Attached Figure Description

[0023] Figure 1 Image of the Mannich base quaternary ammonium salt compound sample prepared in Example 1;

[0024] Figure 2 NMR spectrum of the Mannich base quaternary ammonium salt compound prepared in Example 1;

[0025] Figure 3 Image of the p-dichlorobenzyl bisquinoline quaternary ammonium salt sample prepared in Example 5;

[0026] Figure 4 The nuclear magnetic resonance spectrum of the p-dichlorobenzyl bisquinoline quaternary ammonium salt prepared in Example 5. Detailed Implementation

[0027] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0028] A first aspect of the present invention provides a Mannich base quaternary ammonium salt compound, wherein the compound has the structure shown in formula (1):

[0029]

[0030] R1 and R2 are each independently selected from hydrogen, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, C1-C5 alkoxy or hydroxy-substituted C1-C5 alkyl; X is selected from one or more of F, Cl and Br.

[0031] In some embodiments of the present invention, R1 and R2 are each independently selected from hydrogen, methyl, ethyl or isopropyl.

[0032] In some embodiments of the present invention, preferably, the compound may be selected from at least one of the following compounds:

[0033]

[0034] In this invention, the composition and structure of the above-mentioned compounds can be determined by NMR, IR, GPC, elemental analysis, etc., or by preparation and feeding.

[0035] A second aspect of the present invention provides a method for preparing a Mannich base quaternary ammonium salt compound, comprising the following steps:

[0036] 1) Formaldehyde, compound A, solvent and concentrated hydrochloric acid are mixed and subjected to the first reaction to obtain the product;

[0037] 2) The product is reacted with compound B in a second reaction to obtain Mannich base compounds;

[0038] 3) The Mannich base compound is reacted with compound C in a third reaction and then distilled under reduced pressure to obtain the Mannich base quaternary ammonium salt compound;

[0039] Compound A has the structure shown in formula (2): Compound B has the structure shown in formula (3): Compound C has the structure shown in formula (4): Where X is selected from F, Cl or Br; the definitions of R1 and R2 are the same as those in the first aspect.

[0040] In some embodiments of the present invention, R1 and R2 are each independently selected from hydrogen, methyl, ethyl or isopropyl.

[0041] In some embodiments of the present invention, preferably, compound A is selected from... At least one of them;

[0042] Compound B is selected from At least one of (3-4);

[0043] Compound C is selected from At least one of (4-1).

[0044] In some embodiments of the present invention, the solvent is dimethylformamide and / or an alcohol solvent.

[0045] In some embodiments of the present invention, the first reaction temperature is 90-140°C and the first reaction time is 1-5 hours.

[0046] In some embodiments of the present invention, preferably, the first reaction temperature is 110-120°C and the first reaction time is 2-3 hours.

[0047] In some embodiments of the present invention, the second reaction temperature is 90-140°C and the second reaction time is 3-8 hours.

[0048] In some embodiments of the present invention, preferably, the second reaction temperature is 110-120°C and the second reaction time is 4-6 hours.

[0049] In some embodiments of the present invention, the third reaction temperature is 90-130°C and the third reaction time is 5-10 hours.

[0050] In some embodiments of the present invention, preferably, the third reaction temperature is 110-120°C and the third reaction time is 6-8 hours.

[0051] In some embodiments of the present invention, the pressure of vacuum distillation is -0.05 MPa to -0.15 MPa, preferably -0.07 MPa to -0.1 MPa.

[0052] In some embodiments of the present invention, the molar ratio of formaldehyde, compound A and compound B is 1-2:1-2:0.8-2, preferably 1.2-1.5:1.2-1.5:1-1.5.

[0053] In some embodiments of the present invention, the molar ratio of Mannich base compounds to compound C is 0.8-2:0.2-1, preferably 1-1.5:0.4-0.8.

[0054] A third aspect of the present invention provides an acid corrosion inhibitor, wherein, based on the total amount of the acid corrosion inhibitor, the acid corrosion inhibitor comprises: 15-40 wt% of a Mannich base quaternary ammonium salt compound, 15-40 wt% of a dichlorobenzyl bisquinoline quaternary ammonium salt, 3-15 wt% of potassium iodide, 5-30 wt% of a phenacetin compound, 5-20 wt% of an alkynyl alcohol compound, 2-15 wt% of an antimony salt, and 2-40 wt% of a saturated alcohol compound.

[0055] In this invention, both Mannich base quaternary ammonium salts and p-dichlorobenzyl bisquinoline quaternary ammonium salts are the main components, enabling the corrosion inhibitor to adsorb and form a protective film on the metal surface. Alkyne alcohols, with their relatively small molecular size, can adsorb and protect within the intermolecular gaps of the main protective film, serving as a beneficial supplement to the main agent. Potassium iodide works synergistically with the other components to promote adsorption and protection. Antimony salts promote adsorption and film formation. Pingpingjia acts as a surfactant, promoting uniform dispersion and adsorption of other components, while saturated alcohols act as dissolvers and dispersers. The synergistic effect of the various components in this invention results in an acidification corrosion inhibitor within the aforementioned component range that is both high-temperature resistant and possesses excellent corrosion inhibition properties, thereby improving the corrosion resistance of oil and gas extraction equipment. It is suitable for acidification processes of oil and gas channels in high-temperature reservoirs at 160-180℃.

[0056] The acidizing corrosion inhibitor described in this invention is composed of specific components in specific amounts and is applicable to the acidizing process of oil and gas channels in high-temperature reservoirs at 160-180°C.

[0057] In some embodiments of the present invention, the content of the Mannich base quaternary ammonium salt can be selected from 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, and any value within the range of any two of the above values.

[0058] In some embodiments of the present invention, the mass percentage of the dichlorobenzyl bisquinoline quaternary ammonium salt can be selected from 15wt%, 20wt%, 25wt%, 30wt%, 35wt%, 40wt%, and any value within the range of any two of the above values.

[0059] In some embodiments of the present invention, the mass percentage of potassium iodide may be selected as 3wt%, 5wt%, 10wt%, 15wt%, or any value within the range of any two of the above values.

[0060] In some embodiments of the present invention, the mass percentage of the added material can be selected as 5wt%, 10wt%, 15wt%, 20wt%, 25wt%, 30wt%, or any value within the range of any two of the above values.

[0061] In some embodiments of the present invention, the mass percentage of the alkynol compound may be selected as 5 wt%, 10 wt%, 15 wt%, 20 wt%, or any value within the range of any two of the above values.

[0062] In some embodiments of the present invention, the mass percentage of the antimony salt may be selected as 2wt%, 5wt%, 10wt%, 15wt%, or any value within the range of any two of the above values.

[0063] In some embodiments of the present invention, the mass percentage of the saturated alcohol compound may be selected from 2wt%, 10wt%, 15wt%, 25wt%, 30wt%, 35wt%, 40wt%, and any value within the range of any two of the above values.

[0064] In some embodiments of the present invention, the acid corrosion inhibitor comprises the following components by mass percentage: 20-30 wt% Mannich base quaternary ammonium salt, 20-30 wt% p-dichlorobenzyl bisquinoline quaternary ammonium salt, 5-10 wt% potassium iodide, 10-20 wt% phenacetin, 10-15 wt% alkynyl alcohol compound, 5-10 wt% antimony salt, and 5-35 wt% saturated alcohol compound.

[0065] In some embodiments of the present invention, the antimony salt is selected from antimony chloride and antimony carbonate.

[0066] In some embodiments of the present invention, the alkynol compound is selected from methylpentynol and / or propynol; preferably methylpentynol.

[0067] In some embodiments of the present invention, the saturated alcohol compound is selected from isopropanol and / or ethanol, preferably isopropanol.

[0068] In some embodiments of the present invention, the methyl methacrylate (MCM) is a fatty alcohol polyoxyethylene ether with the structural formula RO(CH2CH2O). n H, R = C 16 -C 18 , n = 9 - 30.

[0069] In some embodiments of the present invention, the p-dichlorobenzyl bisquinoline quaternary ammonium salt has the structure shown in formula (4):

[0070]

[0071] In some embodiments of the present invention, the p-dichlorobenzyl bisquinoline quaternary ammonium salt is prepared using quinoline and 1,4-p-dichlorobenzyl as reactants.

[0072] In some embodiments of the present invention, the method for preparing the dichlorobenzyl bisquinoline quaternary ammonium salt includes the following steps:

[0073] 1) Quinoline, 1,4-dichlorobenzyl, and water were mixed and heated to allow for reflux reaction;

[0074] 2) The system after the reaction is heated and concentrated, cooled and crystallized to obtain a crude product. The crude product is then recrystallized, filtered and dried to obtain a dichlorobenzyl bisquinoline quaternary ammonium salt.

[0075] In some embodiments of the present invention, the reflux reaction temperature is 80-120°C and the reflux reaction time is 4-10 h.

[0076] In some embodiments of the present invention, preferably, the reflux reaction temperature is 90-110°C and the reflux reaction time is 5-8 hours.

[0077] In some embodiments of the present invention, the molar ratio of quinoline to 1,4-dichlorobenzyl is 1-4:1, preferably 2-3:1.

[0078] In some embodiments of the present invention, the amino acid is hydrochloric acid.

[0079] According to a particularly preferred embodiment of the present invention, an acid corrosion inhibitor comprises the following components in weight percentage: 20-30 wt% Mannich base quaternary ammonium salt, 20-30 wt% p-dichlorobenzyl bisquinoline quaternary ammonium salt, 5-10 wt% potassium iodide, 10-20 wt% phenacetin, 10-15 wt% alkynyl alcohol compound, 5-10 wt% antimony salt, and 5-35 wt% saturated alcohol compound;

[0080] The structural formula of the Mannich base quaternary ammonium salt compound is as follows: (1-1), its preparation method includes the following steps:

[0081] 1) Formaldehyde, 2-(methylamino)pyridine, anhydrous ethanol and concentrated hydrochloric acid are mixed and subjected to a first reaction at 110-120℃ for 2-3 hours to obtain the product;

[0082] 2) The product is reacted with 2-acetylpyridine at 110-120°C for 4-6 h to obtain the Mannich base;

[0083] 3) The Mannich base was reacted with 1,4-dichlorobenzyl at 110-120 °C for 6-8 h, and then distilled under reduced pressure at -0.07 MPa to -0.1 MPa to obtain the Mannich base quaternary ammonium salt.

[0084] The molar ratio of formaldehyde, 2-(methylamino)pyridine and 2-acetylpyridine is 1.2-1.5:1.2-1.5:1-1.5, and the molar ratio of Mannich base and 1,4-dichlorobenzyl is 1-1.5:0.4-0.8.

[0085] The structural formula of the p-dichlorobenzyl bisquinoline quaternary ammonium salt is as follows: (4), the preparation method of which includes the following steps:

[0086] 1) Mix quinoline, 1,4-dichlorobenzyl and water, and heat to reflux at 90-110℃ for 5-8 hours;

[0087] 2) The system after the reaction was heated and concentrated, cooled and crystallized to obtain a crude product, and then the crude product was recrystallized, filtered and dried to obtain a dichlorobenzyl bisquinoline quaternary ammonium salt.

[0088] The molar ratio of quinoline to 1,4-dichlorobenzyl is 1-3:1.

[0089] A fourth aspect of the present invention provides an acid solution comprising: an amino acid and the aforementioned acidification and corrosion inhibitor.

[0090] In some preferred embodiments, based on the total amount of the acid solution, the content of the acidification corrosion inhibitor in the acid solution is 2-8 wt%, preferably 2-4 wt%, more preferably 4 wt%; and the content of the basic acid is 15-28 wt%.

[0091] In some preferred embodiments, the amount of the acid corrosion inhibitor is 2-8 wt% of the total weight of the acid solution, for example, 2 wt%, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 7 wt%, 8 wt%, and any value within the range of any two of the above values, preferably 2-4 wt%, more preferably 4 wt%.

[0092] In some preferred embodiments, the amount of the basic acid is 15-28 wt% of the total weight of the acid solution, for example 15 wt%, 18 wt%, 20 wt%, 22 wt%, 25 wt%, 28 wt%, and any value within the range of any two of the above values.

[0093] The fifth aspect of the present invention provides the application of the aforementioned acid solution in high-temperature reservoir oil and gas extraction.

[0094] This invention provides an acidizing corrosion inhibitor composed of specific components in specific amounts, suitable for acidizing oil and gas channels in high-temperature reservoirs at 160-180℃. The corrosion inhibitor system of this invention is both high-temperature resistant and possesses excellent corrosion inhibition properties, thereby improving the corrosion resistance of oil and gas extraction equipment and contributing to a safer, more stable, and more efficient oil and gas extraction process.

[0095] The present invention will be described in detail below through embodiments.

[0096] Unless otherwise specified, the following examples and comparative examples were conducted under standard conditions or conditions recommended by the manufacturer. Reagents and instruments used, unless otherwise specified, are all commercially available products. The composition and structure of the compounds described in the following examples and comparative examples can be determined by NMR, IR, GPC, elemental analysis, or by preparative feeding.

[0097] Preparation Example 1: Preparation of Mannich base quaternary ammonium salt compounds

[0098] 20 mL of anhydrous ethanol, 0.5 mL of concentrated hydrochloric acid, 2 mL of formaldehyde solution, and 2.59 g of 2-(methylamino)pyridine were added to a 50 mL round-bottom flask. The mixture was reacted at 110 °C for 2 h. Then, 2.42 g of 2-acetylpyridine was added, and the reaction was carried out for 4 h to obtain Mannich base compounds. Next, 1.40 g of 1,4-dichlorobenzyl was added, and the reaction was continued at 110 °C for 6 h. Finally, the mixture was distilled under reduced pressure at -0.07 MPa using a rotary evaporator to obtain a deep red Mannich base quaternary ammonium salt compound. The molar ratio of the reactants was approximately: n[formaldehyde]:n[2-(methylamino)pyridine]:n[2-acetylpyridine] = 1.2:1.2:1; n[Mannich base compounds]:n[1,4-dichlorobenzyl] = 1:0.4. An example synthetic equation for a Mannich base quaternary ammonium salt compound is shown below.

[0099]

[0100] The synthesized Mannich base quaternary ammonium salt sample is as follows: Figure 1 As shown.

[0101] NMR analysis of Mannich base quaternary ammonium salts using heavy water as solvent, as follows: Figure 2 As shown in the spectrum, the multiplet at δ2.86 is attributed to the three hydrogen atoms on the methyl group at position 1; the multiplets at δ3.06 and δ3.39 are attributed to the two hydrogen atoms on the methylene groups at positions 2 and 3, respectively; the multiplet at δ4.32 is attributed to the two hydrogen atoms on the methylene group at position 4; and the multiplets from δ6.73 to 7.95 are attributed to the hydrogen atoms on the pyridine and benzene rings at positions 5, 6, 7, and 8. The NMR spectrum indicates that the synthesized Mannich base quaternary ammonium salt is the target product, and its structural formula is...

[0102] Preparation Example 2

[0103] The Mannich base quaternary ammonium salt compound was prepared according to the method of Preparation Example 1. The molar ratio of the materials during the reaction was approximately: n[formaldehyde]:n[2-(methylamino)-4-methylpyridine]:n[2-acetylpyridine] = 2:2:0.8; n[Mannich base compound]:n[1,4-dichlorobenzyl] = 1.2:0.8.

[0104] Wherein, compound A is 2-(methylamino)-4-methylpyridine, compound B is 2-acetylpyridine, and the structural formula of the resulting Mannich base quaternary ammonium salt compound is as follows:

[0105] Preparation Example 3

[0106] The Mannich base quaternary ammonium salt compound was prepared according to the method of Preparation Example 1. The molar ratio of the materials during the reaction was approximately: n[formaldehyde]:n[2-(methylamino)-4-methylpyridine]:n[2-acetyl-5-isopropylpyridine] = 1.5:1.5:1.5; n[Mannich base compound]:n[1,4-dichlorobenzyl] = 1:1.

[0107] Wherein, compound A is 2-(methylamino)-4-methylpyridine, compound B is 2-acetyl-5-isopropylpyridine, and the structural formula of the resulting Mannich base quaternary ammonium salt compound is as follows:

[0108]

[0109] Preparation Example 4

[0110] The Mannich base quaternary ammonium salt compound was prepared according to the method of Preparation Example 1. The molar ratio of the materials during the reaction was approximately: n[formaldehyde]:n[2-(methylamino)-4-ethylpyridine]:n[2-acetyl-5-isopropylpyridine] = 1:1:2; n[Mannich base compound]:n[1,4-dichlorobenzyl] = 2:0.1.

[0111] Wherein, compound A is 2-(methylamino)-4-ethylpyridine, compound B is 2-acetyl-5-isopropylpyridine, and the structural formula of the resulting Mannich base quaternary ammonium salt compound is as follows:

[0112]

[0113] Mannich base quaternary ammonium salt compounds were prepared according to the method of Preparation Example 1. The molar ratios of materials and reaction conditions used in Preparation Examples 2-4 are shown in Table 1.

[0114] Table 1

[0115] project Preparation Example 2 Preparation Example 3 Preparation Example 4 First reaction temperature / °C 120 90 140 First reaction time / h 3 5 1 Second reaction temperature / °C 120 90 140 Second reaction time / h 6 8 3 Third reaction temperature / °C 120 90 130 Third reaction time / h 8 10 5 n[Formaldehyde]:n[Compound A]:n[Compound B] 2:2:0.8 1.5:1.5:1.5 1:1:2 n[Mannich base compounds]: n[1,4-p-dichlorobenzyl] 1.2:0.8 1:1 2:0.2

[0116] Preparation Example 5: Preparation of dichlorobenzyl bisquinoline quaternary ammonium salts

[0117] Add 50 mL of distilled water to a 100 mL three-necked flask. Weigh 7.9863 g of quinoline and 5.4206 g of 1,4-dichlorobenzyl and add them to the flask (the system separates into layers, with a yellow transparent oily upper layer and a transparent water layer lower layer). Connect a reflux condenser and thermometer, and heat on a heating mantle (the transparent water layer gradually turns yellow). After the temperature reaches 100 °C, reflux for 6 hours (the system changes from brownish-red to orange, and a few oil droplets appear on the surface). Stop heating, cool, pour into a crucible, heat to concentrate, cool to crystallize, and obtain a yellow crude product. Recrystallize with anhydrous ethanol, filter, and dry to obtain an earthy-colored final product (5.4962 g). The molar ratio of the materials during the reaction is approximately: n[quinoline]:n[1,4-dichlorobenzyl] = 2:1. The synthesis equation of the dichlorobenzyl bisquinoline quaternary ammonium salt is as follows:

[0118] The prepared p-dichlorobenzylbisquinoline type quaternary ammonium salt sample, such as Figure 3 As shown.

[0119] The NMR spectrum of dichlorobenzyl bisquinoline quaternary ammonium salts using heavy water as solvent is shown below. Figure 4 As shown in the spectrum, the multiplet at δ7.14–7.31 is attributed to the four hydrogen atoms on the benzene ring (number 9), the peak at δ6.1 is attributed to the four hydrogen atoms on the methylene group (number 10) connected to the benzene ring, and the multiplet at δ7.60–9.24 is attributed to the 14 hydrogen atoms on the quinoline ring (number 11). The NMR spectrum indicates that the synthesized p-dichlorobenzyl bisquinoline quaternary ammonium salt is the target product, and its structural formula is...

[0120]

[0121] Preparation Examples 6-8

[0122] The dichlorobenzyl bisquinoline quaternary ammonium salt was prepared according to the method of Preparation Example 5. The molar ratios of the materials and the reaction conditions used in Preparation Examples 6-8 are shown in Table 2.

[0123] Table 2

[0124] project Preparation Example 6 Preparation Example 7 Preparation Example 8 Reflux reaction temperature / °C 90 110 120 Reflux reaction time / h 6 8 10 n[quinoline]: n[1,4-p-dichlorobenzyl] 2:1 3:1 4:1

[0125] Examples 1-7

[0126] Prepare the acid corrosion inhibitors for Examples 1-7 according to the formulas in Table 3.

[0127] Add the prepared acid corrosion inhibitor to the hydrochloric acid solution according to the proportions in Table 3 to obtain the acid product.

[0128] Table 3

[0129]

[0130] Table 3 (continued)

[0131]

[0132] Comparative Examples 1-3

[0133] Prepare acid corrosion inhibitors according to the formulas in Table 4 for comparison ratios 1-3.

[0134] Add the prepared acid corrosion inhibitor to the hydrochloric acid solution according to the proportions in Table 4 to obtain the acid product.

[0135] Table 4

[0136]

[0137] Performance Evaluation

[0138] The corrosion inhibition performance of the acid corrosion inhibitors in each embodiment was evaluated according to SY / T5405-2019 "Test Methods and Evaluation Indicators for Acidification Corrosion Inhibitors". The dynamic corrosion rate under high temperature and pressure was tested using a rotating rock apparatus for acid-rock reaction. The test material was N80 standard steel sheet. After cleaning with acetone to remove oil, the steel sheet dimensions were measured. The sheet was then immersed in anhydrous ethanol, removed, air-dried, and placed in a desiccator for weighing. The weighed steel sheet was placed in acid solution and reacted at the target temperature for 4 hours. The steel sheet was then washed sequentially with water, acetone, and ethanol, dried, weighed, and the corrosion rate was calculated. The test results for each embodiment and comparative example are shown in Table 5.

[0139] Table 5

[0140] serial number Temperature / °C <![CDATA[Corrosion rate / g / (m 2 ·h)]]> Example 1 180 68.85 Example 2 160 35.75 Example 3 160 41.26 Example 4 160 46.32 Example 5 160 55.12 Example 6 160 62.70 Example 7 160 72.14 Comparative Example 1 160 167.48 Comparative Example 2 160 189.38 Comparative Example 3 160 322.89

[0141] Taking Example 3 as an example, the corrosion inhibition test results at 180℃ are shown in Table 6.

[0142] Table 6

[0143]

[0144] As can be seen from the results in Table 1, the embodiments of the present invention meet the requirements of the industry standard SY / T5405-2019 "Test Methods and Evaluation Indicators for Performance of Corrosion Inhibitors for Acidification" and have significantly better effects.

[0145] As can be seen from the results in Table 5, compared with Examples 1-7, the corrosion rate of the acidizing corrosion inhibitor obtained in Comparative Example 1 without the addition of dichlorobenzyl bisquinoline quaternary ammonium salt increased sharply, and the corrosion inhibition performance was poor. The corrosion rate of the acidizing corrosion inhibitor obtained in Comparative Example 2 without the addition of Mannich base quaternary ammonium salt compound increased sharply, and the corrosion inhibition performance was poor. The corrosion inhibition performance of the acidizing corrosion inhibitor obtained outside the content range of the present invention was poor. Among them, the acidizing corrosion inhibitor obtained in Example 7 without the addition of potassium iodide had slightly worse corrosion inhibition performance than the other examples. Therefore, the various components of the present invention work synergistically, and the acidizing corrosion inhibitor obtained within the above component range is both high temperature resistant and has excellent corrosion inhibition performance, thereby improving the corrosion resistance of oil and gas extraction equipment. It is suitable for the acidizing process of oil and gas channels in high-temperature reservoirs at 160-180℃.

[0146] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A Mannich base quaternary ammonium salt compound, characterized in that, The compound has the structure shown in formula (1): （1）， R1 and R2 are each independently selected from hydrogen, C1-C5 straight-chain alkyl, C3-C5 branched alkyl, C1-C5 alkoxy or hydroxy-substituted C1-C5 alkyl; X is selected from one or more of F, Cl and Br.

2. The compound according to claim 1, characterized in that, R1 and R2 are each independently selected from hydrogen, methyl, ethyl, or isopropyl.

3. The compound according to claim 1, characterized in that, The compound is selected from at least one of the following compounds: （1-1） （1-2）、 （1-3）、 （1-4）。 4. A method for preparing the Mannich base quaternary ammonium salt compound according to claim 1, characterized in that, Includes the following steps: 1) Formaldehyde, compound A, solvent and concentrated hydrochloric acid are mixed and subjected to the first reaction to obtain the product; 2) The product is reacted with compound B in a second reaction to obtain Mannich base compounds; 3) The Mannich base compound is reacted with compound C in a third reaction and then distilled under reduced pressure to obtain the Mannich base quaternary ammonium salt compound; Compound A has the structure shown in formula (2): (2); Compound B has the structure shown in formula (3): (3); Compound C has the structure shown in formula (4): (4), wherein X is selected from F, Cl or Br; the definitions of R1 and R2 are the same as those in claim 1.

5. The preparation method according to claim 4, characterized in that, R1 and R2 are each independently selected from hydrogen, methyl, ethyl, or isopropyl.

6. The preparation method according to claim 4 or 5, characterized in that, Compound A is selected from (2-1) (2-2) (2-3) At least one of (2-4).

7. The preparation method according to claim 6, characterized in that, The compound B is selected from (3-1) (3-2) (3-3) At least one of (3-4).

8. The preparation method according to claim 7, characterized in that, The compound C is selected from (4-1) (4-2) At least one of (4-3).

9. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The solvent is dimethylformamide and / or an alcohol solvent.

10. The preparation method according to claim 9, characterized in that, The first reaction temperature is 90-140℃, and the first reaction time is 1-5h.

11. The preparation method according to claim 10, characterized in that, The first reaction temperature is 110-120℃, and the first reaction time is 2-3 hours.

12. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The second reaction temperature is 90-140℃, and the second reaction time is 3-8h.

13. The preparation method according to claim 12, characterized in that, The second reaction temperature is 110-120℃, and the second reaction time is 4-6h.

14. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The third reaction temperature is 90-130℃, and the third reaction time is 5-10h.

15. The preparation method according to claim 14, characterized in that, The third reaction temperature is 110-120℃, and the third reaction time is 6-8h.

16. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The pressure for vacuum distillation is -0.15 MPa to -0.05 MPa.

17. The preparation method according to claim 16, characterized in that, The pressure for vacuum distillation is -0.1 MPa to -0.07 MPa.

18. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The molar ratio of formaldehyde, compound A, and compound B is 1-2:1-2:0.8-2.

19. The preparation method according to claim 18, characterized in that, The molar ratio of formaldehyde, compound A and compound B is 1.2-1.5:1.2-1.5:1-1.

5.

20. The preparation method according to any one of claims 4-5 and 7-8, characterized in that, The molar ratio of Mannich bases to compound C is 0.8-2:0.2-1.

21. The preparation method according to claim 20, characterized in that, The molar ratio of Mannich bases to compound C is 1-1.5:0.4-0.

8.

22. An acid corrosion inhibitor, characterized in that, Based on the total amount of the acid corrosion inhibitor, the acid corrosion inhibitor comprises: 15-40 wt% of Mannich base quaternary ammonium salt compound, 15-40 wt% of p-dichlorobenzyl bisquinoline quaternary ammonium salt, 3-15 wt% of potassium iodide, 5-30 wt% of phenacetin, 5-20 wt% of alkynyl alcohol compound, 2-15 wt% of antimony salt, and 2-40 wt% of saturated alcohol compound; Wherein, the Mannich base quaternary ammonium salt compound is the Mannich base quaternary ammonium salt compound according to any one of claims 1-3.

23. The acid corrosion inhibitor according to claim 22, characterized in that, The acid corrosion inhibitor comprises the following components by mass percentage: 20-30 wt% Mannich base quaternary ammonium salt, 20-30 wt% p-dichlorobenzyl bisquinoline quaternary ammonium salt, 5-10 wt% potassium iodide, 10-20 wt% phenacetin, 10-15 wt% alkynyl alcohols, 5-10 wt% antimony salts, and 5-35 wt% saturated alcohols.

24. The acid corrosion inhibitor according to claim 22 or 23, characterized in that, The antimony salt is selected from antimony chloride and antimony carbonate.

25. The acid corrosion inhibitor according to claim 22 or 23, characterized in that, The alkynols are selected from methylpentynol and / or propynol.

26. The acid corrosion inhibitor according to claim 22 or 23, characterized in that, The saturated alcohol compound is selected from isopropanol and / or ethanol.

27. An acid solution, characterized in that, include: The basic acid and the acid corrosion inhibitor according to any one of claims 22-26.

28. The acid solution according to claim 27, wherein, The basic acid is hydrochloric acid; And / or, based on the total amount of the acid solution, the content of the acidifying corrosion inhibitor in the acid solution is 2-8 wt%; the content of the basic acid is 15-28 wt%.

29. The acid solution according to claim 28, wherein, Based on the total amount of the acid solution, the content of the acidification corrosion inhibitor in the acid solution is 2-4 wt%.

30. The acid solution according to claim 27 or 28, wherein, Based on the total amount of the acid solution, the content of the acidification corrosion inhibitor in the acid solution is 4 wt%.

31. The application of the acid solution according to any one of claims 27-30 in the extraction of oil and gas from high-temperature reservoirs.

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