Corrosion inhibitor for oxygen reduction air flooding and preparation method thereof
By preparing a polymer corrosion inhibitor containing an imine structure and a benzene ring, the failure problem of corrosion inhibitors in air-driven oil wells under complex formation conditions was solved, achieving effective protection of the tubing string, especially the part below the packer under high temperature and high pressure environments.
Patent Information
- Application Number
- CN202410633622.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-05-21
- Publication Date
- 2025-11-21
AI Technical Summary
During air-driven oil well operations, corrosion inhibitors are prone to failure under complex formation conditions, leading to severe corrosion of the tubing, especially in the area below the packer under high temperature and high pressure conditions where the protection effect is poor.
A corrosion inhibitor with excellent temperature resistance was prepared by mixing maleic anhydride and ammonia, adding a catalyst and lysine solution, and forming a polyamino acid solution through a cross-linking reaction. The cross-linking reactants were then added dropwise under an inert atmosphere to form a polymer containing an imine structure and a benzene ring. After rotary evaporation, filtration and recrystallization, the resulting product was a corrosion inhibitor.
It improves the adhesion and temperature resistance of corrosion inhibitors on metal surfaces, enabling them to effectively protect the tubing, especially the inner tubing below the packer, under high temperature and high pressure conditions, and reduce corrosion.
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Abstract
Description
TECHNICAL FIELD
[0001] The application belongs to the field of oil field chemistry, and particularly relates to an oxygen-reduced air flooding corrosion inhibitor and a preparation method thereof. BACKGROUND
[0002] Air flooding oil is a method of flooding oil reservoirs by injecting air into the stratum, which can effectively maintain the stratum pressure, reduce the viscosity of crude oil, and produce a thermal expansion effect on the crude oil, and is a good medium for supplementing the stratum energy and is more suitable for the development requirements of low-permeability oil reservoirs.
[0003] However, the oxygen corrosion problem restricts the application of air flooding. On the one hand, due to the serious heterogeneity of the sedimentary oil reservoir, direct injection can easily cause gas channeling, and when the air and natural gas are mixed in the wellbore and bottom pipeline, there is an explosion risk. To solve this problem, the air flooding process is assisted by foam, and when the oxygen is mixed with the liquid in the foam, it can cause strong corrosion of the pipe string. On the other hand, in order to reduce the problems of explosion and pipe string corrosion, oxygen-reduced air flooding is currently more commonly used, but even if the oxygen content control flooding is implemented, the water introduced into the reservoir during the construction process and the water produced by the reservoir itself can also cause strong corrosion of the pipe string in the presence of oxygen. Therefore, in addition to strictly controlling the oxygen content in the air, a corresponding corrosion inhibitor is often introduced to protect the pipe string during the air flooding process, which can be used to coat the pipe string before it is lowered into the well, or a protective fluid is injected after the pipe string is lowered into the well, so that the corrosion inhibitor in the protective fluid is adsorbed on the surface of the pipe string to form a protection.
[0004] According to the results of a large number of practical applications, the main problem of air flooding is the corrosion protection failure of the inner pipe below the packer and the outer wall of the pipe string under high temperature, pressure and salinity conditions. Among them, the ground pipeline part and the inner wall of the oil pipe can be protected by an inner coating, and the corrosion inhibitor used to protect the pipe string under complex stratum conditions is easily affected by the environment and fails, resulting in serious corrosion. Therefore, improving the stability of the corrosion inhibitor under complex stratum conditions has become a problem that needs to be solved in the field of air flooding. SUMMARY
[0005] The application provides an oxygen-reduced air flooding corrosion inhibitor and a preparation method thereof, which solves the problem that the corrosion inhibitor used to protect the pipe string under complex stratum conditions is easily affected by the environment and fails, resulting in serious corrosion.
[0006] To achieve the above-mentioned purpose, the application provides the following technical scheme:
[0007] A preparation method of an oxygen-reduced air flooding corrosion inhibitor, comprising:
[0008] After mixing maleic anhydride with ammonia water, first stirring is performed, then the temperature is raised to a first set temperature to obtain a mixed solution;
[0009] A catalyst and a lysine solution are added to the mixed solution, and stirring is performed to obtain a polyamino acid solution;
[0010] After the polyamino acid solution is heated to a second set temperature, a cross-linking reactant solution is added to the polyamino acid solution under stirring in an inert atmosphere for a set time, and then stirring is performed;
[0011] After stirring is completed, rotary evaporation, filtration, and recrystallization are performed in sequence, the recrystallized product is collected and dried to obtain an oxygen-reduced air flooding corrosion inhibitor.
[0012] Preferably, the mass ratio of maleic anhydride to ammonia water is 1:(1-2); the lysine solution is obtained by completely dissolving lysine in N,N-dimethylformamide; and the molar ratio of maleic anhydride to lysine is 1:(0.1-0.3).
[0013] Preferably, the first set temperature is 120-160℃.
[0014] Preferably, the catalyst is one of concentrated phosphoric acid, potassium dihydrogen phosphate, and anhydrous ammonium chloride, and the mass of the catalyst is 0.5-1.5% of the mass of the mixed solution.
[0015] Preferably, the cross-linking reactant solution is obtained by completely dissolving a cross-linking reactant in N,N-dimethylformamide; the cross-linking reactant is p-phenylenedimethanal or 1,3-benzenedimethanal, and the molar ratio of the cross-linking reactant to lysine is (1.5-2):1.
[0016] Preferably, the second set temperature is 80℃, the set time is 15 min, and the inert atmosphere is nitrogen.
[0017] Preferably, the stirring temperature of the first stirring is 90℃, and the stirring time is 10-20 min.
[0018] Preferably, the polyamino acid solution is obtained by adding the catalyst and the lysine solution to the mixed solution and performing stirring, and the stirring time is 1.5-2 h.
[0019] Preferably, the recrystallization is performed for two or more times, the recrystallization is performed using anhydrous ethanol, the drying temperature is 60-70℃, and the drying time is 20-24 h.
[0020] An oxygen-reduced air flooding corrosion inhibitor is prepared according to the foregoing preparation method.
[0021] Compared with the prior art, the present application has the following beneficial effects: the preparation method of the oxygen-reducing air drive corrosion inhibitor provided by the present application comprises the following steps: maleic anhydride is mixed with ammonia water and then stirred for the first time, then the temperature is raised to a first set temperature to obtain a mixed solution, a catalyst and a lysine solution are added to the mixed solution, and the polyamino acid solution is obtained after stirring, the polyamino acid solution is heated to a second set temperature, and then the crosslinking reactant solution is added dropwise to the polyamino acid solution under stirring in an inert atmosphere for a set time, and then the stirring is carried out, and then the rotary evaporation, filtration and recrystallization are carried out in sequence, and the recrystallized product is collected and dried to obtain the oxygen-reducing air drive corrosion inhibitor, which improves the temperature resistance and strengthens the adhesion effect of the corrosion inhibitor on the metal surface, thereby improving the overall temperature resistance of the corrosion inhibitor and enabling it to be effectively applied to the corrosion inhibition of the packer lower end pipe column under high temperature and high pressure harsh conditions. BRIEF DESCRIPTION OF DRAWINGS
[0022] Figure 1 The preparation method of the oxygen-reducing air drive corrosion inhibitor provided by the present application comprises the following steps: DETAILED DESCRIPTION
[0023] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme of the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.
[0024] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those skilled in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.
[0025] In order to make those skilled in the art better understand the technical scheme of the present application, the present application will be further described in detail below with reference to the drawings.
[0026] Specific steps:
[0027] As shown in the drawings, the present application provides a preparation method of an oxygen-reducing air drive corrosion inhibitor, comprising: Figure 1
[0028] S101: mix maleic anhydride with concentrated ammonia water and stir for 10-20 min, then raise the temperature to 120-160 DEG C; the mass ratio of maleic anhydride to concentrated ammonia water is 1:(1-2),
[0029] S102: Add lysine completely dissolved by N,N-dimethylformamide and 0.5-1.5% of catalysts in total mass of reactants, and stir for 1.5-2h to obtain polyamino acid solution; the molar ratio of maleic anhydride to lysine is 1:(0.1-0.3), and the catalysts are one of concentrated phosphoric acid, potassium dihydrogen phosphate, and anhydrous ammonium chloride.
[0030] S103: Warm the polyamino acid solution to 80°C, and under the condition of nitrogen protection, add the cross-linking reactant completely dissolved by N,N-dimethylformamide to the solution by stirring dropwise within 15min, and then perform stirring reaction; the cross-linking reactant is one of p-phenylenedimethanal and 1,3-benzenedimethanal, and the molar ratio of cross-linking reactant to lysine is 1.5-2:1.
[0031] S104: After the reaction is completed, perform rotary evaporation, filtration, multiple recrystallization using anhydrous ethanol, collect the recrystallized product, dry at 60°C for 24h, and crush to obtain the product.
[0032] Example 1
[0033] Weigh 19.6g of maleic anhydride into 19.6g of concentrated ammonia water, warm the obtained solution to 90°C, and then mix and stir for 10min, and then continue to warm to 120°C to obtain a mixed solution, add lysine 2.92g dissolved in 100mL of N,N-dimethylformamide to the mixed solution, and add 0.21g of concentrated phosphoric acid as a catalyst, and keep stirring reaction for 1.5h, and then control the temperature of the obtained solution at 80°C, and protect by nitrogen, and add p-phenylenedimethanal 4.02g dissolved in 100ml of N,N-dimethylformamide dropwise to it within 10min, and perform stirring reaction at 85°C for 3h under the protection of nitrogen, and after the reaction is completed, perform rotary evaporation to remove the solvent and filtration, collect the filtered product, recrystallize it 3 times using anhydrous ethanol, and collect the recrystallized product, dry at 60°C for 24h, and crush to obtain the powder product.
[0034] Example 2
[0035] Take 19.6 g of maleic anhydride into 39.2 g of concentrated ammonia water, the resulting solution is heated to 90°C after mixing and stirring for 10 min, then continue to heat to 160°C, add lysine 8.76 g dissolved in 100 ml of N, N- dimethylformamide, and add 1.01 g of potassium dihydrogen phosphate, keep stirring for 2 h, then control the temperature of the resulting solution at 80°C, protect it with nitrogen, drop 1, 3- benzene dimethylaldehyde 16.08 g dissolved in 200 ml of N, N- dimethylformamide into it within 15 min, stir for 5 h at 90°C under nitrogen, after the reaction is completed, remove the solvent by rotary evaporation and filter, collect the filtered product, recrystallize it with anhydrous ethanol for 3 times, collect the recrystallized product, dry it at 60°C for 24 h, and crush it to get the powder product.
[0036] Example 3
[0037] Take 19.6 g of maleic anhydride into 29.4 g of concentrated ammonia water, the resulting solution is heated to 90°C after mixing and stirring for 15 min, then continue to heat to 140°C, add lysine 5.84 g dissolved in 100 ml of N, N- dimethylformamide, and add 0.55 g of anhydrous ammonium chloride, keep stirring for 2 h, then control the temperature of the resulting solution at 80°C, protect it with nitrogen, drop 1, 3- benzene dimethylaldehyde 8.04 g dissolved in 100 ml of N, N- dimethylformamide into it within 15 min, stir for 4 h at 90°C under nitrogen, after the reaction is completed, remove the solvent by rotary evaporation and filter, collect the filtered product, recrystallize it with anhydrous ethanol for 3 times, collect the recrystallized product, dry it at 60°C for 24 h, and crush it to get the powder product.
[0038] Example 4
[0039] Take 19.6 g of maleic anhydride into 29.4 g of concentrated ammonia water, the resulting solution is heated to 90°C after mixing and stirring for 10 min, then continue to heat to 140°C, add lysine 4.38 g dissolved in 100 ml of N, N- dimethylformamide, and add 0.53 g of concentrated phosphoric acid, keep stirring for 2 h, then control the temperature of the resulting solution at 80°C, protect it with nitrogen, drop 1, 3- benzene dimethylaldehyde 6.03 g dissolved in 100 ml of N, N- dimethylformamide into it within 15 min, stir for 4 h at 90°C under nitrogen, after the reaction is completed, remove the solvent by rotary evaporation and filter, collect the filtered product, recrystallize it with anhydrous ethanol for 3 times, collect the recrystallized product, dry it at 60°C for 24 h, and crush it to get the powder product.
[0040] Comparative Example 1
[0041] Take 19.6 g of maleic anhydride into 19.6 g of concentrated ammonia water, the resulting solution is heated to 90 °C after mixing stirring 10 min, then continue to heat to 120 °C, add 2.92 g of lysine dissolved in 100 ml of N, N- dimethylformamide and 0.21 g of concentrated phosphoric acid, keep stirring reaction 1.5 h, rotary evaporation of the reaction solution, filtration, the resulting solid is washed with acetone 3 times, dried at 60 °C for 6 h to obtain solid product.
[0042] Comparative example 2
[0043] Take 19.6 g of maleic anhydride into 39.2 g of concentrated ammonia water, the resulting solution is heated to 90 °C after mixing stirring 10 min, then continue to heat to 160 °C, add 8.76 g of lysine dissolved in 100 ml of N, N- dimethylformamide and 1.01 g of concentrated phosphoric acid, keep stirring reaction 2 h, rotary evaporation of the reaction solution, filtration, the resulting solid is washed with acetone 3 times, dried at 60 °C for 6 h to obtain solid product.
[0044] The test results are as follows:
[0045] I. Corrosion resistance test:
[0046] The static coupon weight loss method is used to test the corrosion resistance of the product. The test solution simulates the water used in some oilfields, and the main ion concentrations are as follows: sodium ion 10 g / L, calcium ion 2 g / L, sulfate ion 0.05 g / L, carbonate ion 0.3 g / L, potassium ion 2 g / L, magnesium ion 1 g / L, and the rest is chloride ion.
[0047] The test uses N80 steel coupons with dimensions of 50 x 20 x 3 mm as blank samples. The specific test operation is as follows: 5 L of test solution is filled into a high temperature and high pressure kettle to ensure that the blank sample is completely immersed in the test solution inside the kettle. The temperature in the kettle is raised to 120 °C, and 5% oxygen-reduced air is pumped into the high temperature and high pressure kettle, and the pressure is increased to 30 MPa. After keeping the conditions for 7 days, the corrosion rate of the blank sample is determined by weight loss method.
[0048] The sample using the corrosion inhibitor also uses a 50mmx20mmx3mm N80 steel sheet as a sample, and the corrosion inhibitor can be added to water to configure a protective solution to immerse the sample, or can be configured as a corrosion inhibitor liquid surface spraying form for use, and in this case, a protective solution with relatively weak protective effect is selected for testing, and the specific test operation is as follows: the corrosion inhibitor is added to the test solution at a mass concentration of 200mg / L, and the steel bottle is immersed in the test solution in the high temperature and high pressure kettle with the corrosion inhibitor, the temperature in the kettle is raised to 120℃, and the oxygen volume of 5% of the oxygen reducing air is pumped into the high temperature and high pressure kettle, and the pressure is increased to 30MPa, and the condition test is kept for 7d, and then the weight loss method is used to measure the corrosion rate of the blank sample.
[0049] The specific results of the test of the examples and the comparative examples are shown in Table 1:
[0050] Table 1: Corrosion inhibition effect test results
[0051]
[0052] The calculation method of the corrosion rate V is shown in formula (1):
[0053]
[0054] In formula (1), △W is the weight loss of the sample before and after the corrosion experiment, g; ρ is the density of the sample steel sheet, g / cm 3 ; t is the experimental time, h; s is the area of the sample steel sheet, cm 2 .
[0055] The calculation method of the release rate η is shown in formula (2):
[0056]
[0057] In formula (2), V0 is the corrosion rate of the steel sheet as a blank sample, mm·a -1 ; V is the corrosion rate of the steel sheet with the corrosion inhibitor, mm·a -1 .
[0058] Based on the results in Table 1, it can be seen that the corrosion rates of the samples in each group to which the corrosion inhibitor in each group is added are significantly reduced, and the sample to which the corrosion inhibitor in the comparative example is added has a certain corrosion inhibition effect relative to the blank sample. This is because the corrosion inhibitor in the examples introduces an aldehyde with a benzene ring on the basis of the amino acid copolymer including lysine acid, so that the aldehyde group reacts with the amino group of the lysine side chain to form an imine structure, thereby introducing a part of the benzene ring to the copolymer. The imine group can effectively enhance the adsorption on the metal surface, and the benzene ring can improve the temperature resistance to a certain extent. In the comparative example, the amino acid copolymer formed alone can also be adsorbed on the metal surface, that is, it has a certain corrosion inhibition effect, but it is easily affected by temperature and decomposed and desorbed, resulting in a significant difference in corrosion inhibition effect relative to the examples.
[0059] In addition, the corrosion inhibition rate of the group corresponding to Example 2 is the highest, which may be because the raw material usage of the corrosion inhibitor in Example 2 is larger and the reaction time is longer, so that more imine structures are introduced into the polymer, enhancing its adsorption capacity with metal atoms, so that the corrosion inhibitor can be adsorbed on the surface of the steel sheet for a longer time to play a protective role.
[0060] II. Temperature resistance test
[0061] The corrosion inhibitor in Example 2 is selected, and on the basis of setting a blank sample, the temperature resistance test is carried out by using the above-mentioned steps for corrosion resistance test, the difference being that the temperature condition is changed, and the rest of the test conditions remain unchanged. The specific results are shown in Table 2:
[0062] Table 2 Temperature resistance test results
[0063]
[0064] According to the results shown in Table 2, it can be seen that under high temperature conditions above 120℃, the sample using Example 2 as the corrosion inhibitor still has good corrosion inhibition performance, proving that the corrosion inhibitor in the present application has certain temperature resistance effect and can be applied to scenes under high temperature conditions.
[0065] In summary, the present application copolymerizes aspartic acid with part of lysine with an amino branch to form a polymer, and introduces a phenyl aldehyde on the amino group of the lysine branch to form an imine structure containing a benzene ring. On the one hand, the imine structure improves the bonding effect with the metal surface, and on the other hand, the benzene ring also improves the temperature resistance of the whole polymer, so that the corrosion inhibitor in the present application can be stably adsorbed on the metal surface under relatively high temperature conditions, improving its protection effect on part of the casing in the deep formation in the oxygen-reduced air drive construction, so that the corrosion inhibitor in the present application has a large application range and good corrosion inhibition effect.
[0066] Although the embodiments of the present application have been described above with reference to the accompanying drawings, the present application is not limited to the above-described specific embodiments and areas of application, and the above-described specific embodiments are merely illustrative and instructive, but are not restrictive. Those skilled in the art can make various modifications under the teachings of the specification, and such modifications are also within the scope of the present application protected by the claims.
Claims
1. A method for preparing an oxygen-reducing air-driven corrosion inhibitor, characterized in that, include: After mixing maleic anhydride and ammonia, the mixture is stirred for the first time, and then heated to the first set temperature to obtain a mixed solution. A catalyst and lysine solution were added to the mixed solution, and the mixture was stirred to obtain a polyamino acid solution. After heating the polyamino acid solution to the second set temperature, stir and add the crosslinking reactant solution dropwise to the polyamino acid solution within a set time in an inert atmosphere, and then stir. After stirring, the mixture is subjected to rotary evaporation, filtration, and recrystallization in sequence. The recrystallized product is collected and dried to obtain an oxygen-reduced air-driven corrosion inhibitor.
2. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 1, characterized in that, The mass ratio of maleic anhydride to ammonia is 1:(1-2); the lysine solution is obtained by completely dissolving lysine in N,N-dimethylformamide; the molar ratio of maleic anhydride to lysine is 1:(0.1-0.3).
3. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 2, characterized in that, The first set temperature is 120-160℃.
4. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 2, characterized in that, The catalyst is one of concentrated phosphoric acid, potassium dihydrogen phosphate, and anhydrous ammonium chloride, and the mass of the catalyst is 0.5-1.5% of the mass of the mixed solution.
5. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 2, characterized in that, The crosslinking reactant solution is obtained by completely dissolving the crosslinking reactant in N,N-dimethylformamide; the crosslinking reactant is terephthalaldehyde or 1,3-benzaldehyde, and the molar ratio of the crosslinking reactant to lysine is (1.5-2):
1.
6. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 1, characterized in that, The second set temperature is 80°C, the set time is 15 minutes, and the inert atmosphere is nitrogen.
7. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 1, characterized in that, The stirring temperature for the first stirring is 90℃, and the stirring time is 10-20 minutes.
8. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 1, characterized in that, The catalyst and lysine solution are added to the mixed solution, and the mixture is stirred to obtain a polyamino acid solution, wherein the stirring time is 1.5-2 hours.
9. The method for preparing an oxygen-reducing air-driven corrosion inhibitor according to claim 1, characterized in that, The recrystallization is performed at least twice, anhydrous ethanol is used for recrystallization, the drying temperature is 60-70℃, and the drying time is 20-24 hours.
10. A corrosion inhibitor for oxygen-reducing air-driven applications, characterized in that, The oxygen-reducing air-driven corrosion inhibitor is prepared according to any one of claims 1-9.