Metal corrosion control method based on sodium houttuyfonate homolog synergy

Abstract

The invention belongs to the technical field of metal corrosion protection, and particularly relates to a metal corrosion control method based on sodium houttuyfonate homolog synergy. According to the method for controlling corrosion of the metal material in the oil and gas field environment based on the sodium houttuyfonate homologues, a small amount of the sodium houttuyfonate homologues are added into a water medium produced by a CO2 saturated oil and gas field, and a stable corrosion inhibitor film layer can be formed on the surface of the metal material through adsorption, so that corrosion of the metal material is efficiently inhibited; and the corrosion inhibition efficiency on metal materials is 90% or above. The sodium houttuyfonate homologues are used for controlling corrosion of metal materials for the first time, a new method is provided for long-acting control of corrosion in industrial acid environments such as oil and gas fields, and the method has important application prospects in the field of metal corrosion protection in the oil and gas field industry.

Description

Technical Field

[0001] This invention belongs to the field of metal corrosion protection technology, specifically relating to a metal corrosion control method based on the synergistic effect of sodium houttuynia cordata homologues. Background Technology

[0002] In the harsh environment of oil and gas fields, steel is highly susceptible to corrosion. This corrosion is a key cause of equipment failure in oil and gas fields, directly impacting normal production and extraction. Therefore, corrosion control of steel in oil and gas field environments is a major challenge, and corrosion inhibitors are crucial agents for effectively mitigating this corrosion. Corrosion inhibitors, also known as corrosion suppressants, are compounds or complexes that, in corrosive environments (mediums), require only small amounts to prevent or slow the corrosion of metals and other materials. Due to their economic, efficient, and easy-to-use advantages, corrosion inhibitors are widely used in the oil and gas industry, machinery, chemical industry, and energy sectors, with the most widespread application in the oil and gas industry.

[0003] Based on their chemical structures, corrosion inhibitors can be broadly classified into inorganic and organic corrosion inhibitors. Inorganic corrosion inhibitors mainly include nitrates, phosphates, and chromates, whose core function is to form a passivation film on the metal surface, thereby achieving corrosion protection. Commonly used organic corrosion inhibitors encompass amines, aldehydes, quaternary ammonium salts, imidazoline compounds, as well as organosulfur and phosphorus compounds and heterocyclic compounds. They function by forming an adsorption film on the metal surface, preventing corrosive media from contacting the metal surface. Because organic corrosion inhibitors are generally more efficient, reliable, and easier to use, they are more widely used in actual production.

[0004] Many traditional corrosion inhibitors exhibit biological and environmental toxicity, easily causing secondary environmental pollution, and these problems are becoming increasingly prominent. Therefore, the development of low-toxicity, highly efficient, and environmentally friendly green corrosion inhibitors has become a current research hotspot in this field. Currently, many natural extracts and drugs are used for metal corrosion control in acidic environments, such as violet extract, peppermint extract, and ginkgo leaf extract. However, the components and structures of these extract-based corrosion inhibitors are unclear, making large-scale synthesis and application difficult. Houttuynia cordata's active ingredient, houttuynin, and its sodium bisulfite addition product—sodium houttuynin and its homologues—possess advantages such as well-defined molecular structures, large-scale synthesis capabilities, and environmental friendliness. However, there are currently no reports on the use of sodium houttuynin homologues for metal corrosion control, and their inhibitory mechanism against metal corrosion remains unclear. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, this invention proposes a metal corrosion control method based on the synergistic effect of sodium houttuynia cordata homologues. This method utilizes the adsorption of oxygen atoms of sodium houttuynia cordata homologues on the surface of metal materials to form a monomolecular film, thereby achieving the purpose of inhibiting metal corrosion. It is expected to be applied to the control of metal corrosion in oil and gas fields.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: This invention provides a method for controlling metal corrosion based on sodium houttuynia cordata homologues, specifically: adding sodium houttuynia cordata homologues to a corrosive medium can inhibit the corrosion of metallic materials in the corrosive medium; the sodium houttuynia cordata homologues are selected from at least one of CI-1, CI-2, CI-3, or CI-4. .

[0007] The metal corrosion control method of this invention utilizes the adsorption and film-forming properties of sodium houttuynia cordata on metal surfaces. By adding a certain concentration of sodium houttuynia cordata to acidic corrosive solutions in oil and gas fields, a monomolecular corrosion-inhibiting adsorption film can be constructed on the metal surface, thereby achieving a good corrosion control effect. Because sodium houttuynia cordata is low in toxicity, environmentally friendly, and can be synthesized on a large scale, this method can provide technical support for corrosion control of metal materials in oil and gas field environments.

[0008] Preferably, the sodium houttuynia cordata homologues are selected from CI-1 and CI-2, or CI-2 and CI-3, or CI-3 and CI-4, or CI-1 and CI-3. The corrosion inhibition efficiency of sodium houttuynia cordata homologues used alone is above 80%, and the corrosion inhibition efficiency of sodium houttuynia cordata homologues used in combination is above 90%.

[0009] Preferably, the concentration of the sodium houttuynia cordata homologue is 1-500 mg / L.

[0010] More preferably, the concentration of the sodium houttuynia cordata homologue added is 1-200 mg / L.

[0011] Preferably, the metallic material includes carbon steel and copper-nickel alloy.

[0012] Preferably, the corrosive medium is an oil and gas field corrosive solution, specifically an acidic corrosive medium saturated with CO2.

[0013] Preferably, the sodium houttuynia cordata homologues exert a corrosion protection effect by adsorbing and forming a film on the surface of the metal material.

[0014] The second aspect of the present invention also provides the application of the metal corrosion control method described in the first aspect in the control of metal corrosion in oil and gas fields.

[0015] Compared with the prior art, the beneficial effects of the present invention are: Corrosion is a major cause of service failure in oil and gas field pipeline materials. Therefore, this invention discloses a metal corrosion control method based on sodium houttuynia cordata homologues. This method utilizes the adsorption of oxygen atoms from sodium houttuynia cordata homologues on the surface of metal materials to synergistically form a monomolecular corrosion inhibitor film, thereby achieving highly efficient inhibition of metal corrosion and making it suitable for controlling metal corrosion in oil and gas fields. The sodium houttuynia cordata homologues used in this invention are low in toxicity and environmentally friendly, will not cause secondary pollution to the environment, and are easy to synthesize on a large scale, providing a good method for corrosion control of metal materials in oil and gas field environments. This invention utilizes sodium houttuynia cordata homologues to achieve corrosion control of metal materials in oil and gas field environments, and has significant application prospects in the field of corrosion control in oil and gas field industrial environments. Attached Figure Description

[0016] Figure 1 The weight loss of carbon steel after 7 days of corrosion in a saturated CO2 corrosive medium containing different concentrations of sodium houttuynia cordata homologues (CI-1, CI-2, CI-3, or CI-4).

[0017] Figure 2 The corrosion inhibition efficiency of sodium houttuynia cordata homologues (CI-1, CI-2, CI-3, or CI-4) on carbon steel after 7 days of corrosion in a saturated CO2 corrosive medium.

[0018] Figure 3 Scanning electron microscope (SEM) images of carbon steel after 7 days of corrosion in saturated CO2 media with or without the addition of sodium houttuynia cordata: (a and b) blank control; (c) CI-1; (d) CI-2; (e) CI-3; (f) CI-4.

[0019] Figure 4 The synergistic corrosion inhibition efficiency of sodium houttuynia cordata homologues at a concentration of 20 mg / L is given for carbon steel after 7 days of corrosion in a saturated CO2 corrosive medium.

[0020] Figure 5 The results are the molecular dynamics calculations of the adsorption of sodium houttuynia cordata homologues on the Fe (110) crystal plane. Detailed Implementation

[0021] The specific embodiments of the present invention will be further described below. It should be noted that these descriptions are for the purpose of aiding understanding the present invention, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0022] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods, and the experimental materials used in the following embodiments are all available through conventional commercial channels.

[0023] Example 1: Synthesis method of sodium houttuynin homologue The synthesis method of sodium houttuynin homologues is as follows: In a 25 mL dry three-necked flask, 2 mmol of a ketone compound and 10 mL of tetrahydrofuran were added sequentially. After stirring in an ice bath, 2 mmol of potassium tert-butoxide was added and stirred for 5 min. Then, 321 μL of a tetrahydrofuran solution containing ethyl formate (4 mmol) was added dropwise. The reaction was monitored for completeness (room temperature reaction) using thin-layer chromatography. The reaction solution was then concentrated to remove the tetrahydrofuran. Next, 10 mL of anhydrous ethanol was added to the residue and stirred until fully dissolved in an ice bath. Then, 2 mmol of acetic acid was added dropwise and stirred for 10 min. Subsequently, a solution of sodium bisulfite (3 mmol) dissolved in 1 mL of water was added dropwise, and stirring continued for 30 min. The ice bath was removed, and the mixture was stirred overnight at room temperature. The precipitate was then collected by centrifugation. The precipitate was washed sequentially with ice water and cold methanol, and dried to obtain the sodium houttuynia cordata homologue.

[0024] The ketones used in the above reactions are 2-heptanone, or 2-undecanone, or 4,6-dimethyl-2-heptanone, or cyclohexylacetone, and the corresponding final synthetic products are the target houttuynia cordata sodium homologues CI-1, CI-2, CI-3 and CI-4.

[0025] The molecular structures of four sodium houttuynia cordata homologues are shown below: .

[0026] Example 2: Metal corrosion control based on sodium houttuynia cordata homologues The metal corrosion control experiment based on sodium houttuynia cordata homologues includes the following steps: (1) An in-situ corrosion test apparatus was constructed. The test solution simulating the corrosion environment of an oil and gas field was a 3.5 wt% sodium chloride solution saturated with CO2. After the Q235 steel sample was polished, it was weighed using an analytical balance and placed into the apparatus and completely submerged. Subsequently, sodium houttuynia cordata homologues (CI-1, CI-2, CI-3, or CI-4 were added to the test solution. Each homologue was set at four concentrations: 0, 12.5, 50, and 100 mg / L, and three replicates were set for each group of parallel samples. (2) After 7 days of testing, the corrosion samples were taken out and the surface corrosion products were removed by acid washing solution. Then, the samples were washed with alkaline washing solution, water, acetone and anhydrous ethanol in sequence. All samples were dried with nitrogen and weighed. (3) Calculate the corrosion rate and the corrosion inhibition efficiency of the four sodium houttuynia cordata homologues based on the weight loss results.

[0027] like Figure 1 As shown, the corrosion rate of the control sample in the corrosive medium without the addition of sodium houttuynia cordata was as high as (0.248 ± 0.003) mm / y, while the corrosion rate of the steel decreased significantly after the addition of the four sodium houttuynia cordata homologues. When the concentration of CI-1, CI-2, CI-3, and CI-4 was 50 mg / L, the corresponding corrosion rates of the steel were (0.011 ± 0.009), (0.014 ± 0.001), (0.011 ± 0.004), and (0.010 ± 0.004) mm / y, respectively. Figure 2 As shown, the corrosion inhibition efficiencies of the four sodium houttuynia cordata homologues were as high as (95.6 ± 3.4)%, (94.3 ± 0.6)%, (95.7 ± 1.5)%, and (95.8 ± 1.7)%, respectively. These results indicate that the four sodium houttuynia cordata homologues all exhibit excellent corrosion inhibition effects, which is attributed to the adsorption and film formation of the four homologues on the surface of the metal material.

[0028] The sample was characterized by scanning electron microscopy after 7 days of corrosion, and the results are as follows: Figure 3 As shown, in the control group without the addition of sodium houttuynia cordata, a large number of honeycomb-like corrosion products formed on the surface of the corroded sample, further indicating that the steel corrosion was more severe at this time. In contrast, in the corrosive medium with the addition of sodium houttuynia cordata, only a small amount of corrosion products were observed on the sample surface, and surface scratches were clearly visible, indicating that the corrosion was less severe. This result further proves that all four sodium houttuynia cordata homologues have very good corrosion inhibition effects, corresponding to the corrosion weight loss results.

[0029] Meanwhile, the synergistic effect of combined addition of houttuynia cordata homologues (CI-1, CI-2, CI-3, CI-4) was tested using the aforementioned corrosion weight loss test method. The results showed that when CI-1, CI-2, CI-3, and CI-4 were added in combination, and the concentration of each houttuynia cordata homologue was 20 mg / L, the combinations of CI-1+CI-2, CI-2+CI-3, CI-3+CI-4, and CI-1+CI-3 exhibited significant synergistic corrosion inhibition effects, with release efficiencies of 96%, 95%, 94%, and 97%, respectively. Figure 4 The above results demonstrate that the four sodium houttuynia cordata homologues of the present invention exhibit good synergistic corrosion inhibition properties and can be used in combination to enhance corrosion control.

[0030] In addition, to elucidate the corrosion inhibition mechanism of the four sodium houttuynia cordata homologues, molecular dynamics calculations were performed on the adsorption process of the four sodium houttuynia cordata homologues on the steel surface. The results showed that the oxygen atoms in the four sodium houttuynia cordata homologues have a high adsorption energy with the Fe (110) crystal plane, which helps the four sodium houttuynia cordata homologues to adsorb and form a film on the metal surface, thereby exerting a significant slow-release effect. Figure 5 ).

[0031] In summary, the sodium houttuynia cordata homologues (CI-1, CI-2, CI-3, CI-4) exhibit excellent corrosion inhibition performance on steel materials in an acidic CO2-saturated 3.5wt% sodium chloride solution. This is because they synergistically form an excellent monomolecular corrosion-inhibiting adsorption film on the steel surface, indicating that the sodium houttuynia cordata homologues provided by this invention have the potential for corrosion control in oil and gas field environments. Furthermore, these homologues are simple in structure, easy to prepare, low in cost, and environmentally friendly. While possessing high corrosion inhibition efficiency, they also avoid the secondary environmental pollution caused by traditional corrosion inhibitors, providing technical support for efficient corrosion control of steel materials in oil and gas field industries.

[0032] The embodiments of the present invention have been described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of the present invention, and these variations still fall within the protection scope of the present invention.

Claims

1. A method for controlling metal corrosion based on sodium houttuynia cordata homologues, characterized in that, Adding sodium houttuynia cordata homologues to a corrosive medium can inhibit the corrosion of metallic materials in that medium; the sodium houttuynia cordata homologues are selected from at least one of CI-1, CI-2, CI-3, or CI-4. 。 2. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 1, characterized in that, The sodium houttuynia cordata homologues are selected from CI-1 and CI-2, or CI-2 and CI-3, or CI-3 and CI-4, or CI-1 and CI-3.

3. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 1, characterized in that, The concentration of the sodium houttuynia cordata homologue added is 1-500 mg / L.

4. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 3, characterized in that, The concentration of the sodium houttuynia cordata homologue added is 1-200 mg / L.

5. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 1, characterized in that, The metallic materials include carbon steel and copper-nickel alloys.

6. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 1, characterized in that, The corrosive medium is an oil and gas field corrosive solution.

7. The method for controlling metal corrosion based on sodium houttuynia cordata homologues according to claim 1, characterized in that, The sodium houttuynia cordata homologues exert their corrosion protection effect by adsorbing and forming a film on the surface of metal materials.

8. The application of the metal corrosion control method according to any one of claims 1-7 in the metal corrosion control of oil and gas fields.

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