Corrosion inhibition bactericide for inhibiting subscale corrosion of subsea pipeline and preparation method thereof

Abstract

The invention discloses a corrosion inhibition bactericide for inhibiting subscale corrosion of a subsea pipeline and a preparation method of the corrosion inhibition bactericide. The method comprises the following steps: uniformly mixing and stirring aminopyridine and aminoquinoline, slowly dropwise adding a hydroxide aqueous solution, cooling to below 30 DEG C after dropwise adding, slowly dropwise adding carbon disulfide with the temperature not exceeding 40 DEG C in the whole dropwise adding process, reacting for 8-12 hours at 20-40 DEG C after dropwise adding, and blowing nitrogen for 30 minutes to obtain an intermediate A, adding distilled water and a complex platinum catalyst, carrying out reflux reaction for 2-4 hours at the temperature of 100-110 DEG C, adding glutaraldehyde and isothiazolinone, carrying out reflux reaction for 2-4 hours, cooling to 60 DEG C or below, adding a sulfur-containing compound and low-molecular alcohol, and stirring and dissolving to obtain the sulfur-containing compound. The invention aims at corrosion and bacteria under the scale of the offshore oilfield subsea pipeline, has the advantages of small dosage, good permeability, high corrosion inhibition rate and high sterilization rate, and is suitable for relieving the corrosion under the scale of the subsea pipeline and killing the bacteria under the scale.

Description

Technical Field

[0001] The present invention relates to the technical field of oilfield corrosion and protection, and in particular to a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of marine pipes and a preparation method thereof. Background Art

[0002] As offshore oil fields continue to increase reserves and production, the transportation volume of submarine pipelines continues to increase. Under-scale corrosion caused by scaling problems has become increasingly prominent, and the growth of bacteria under scale is also becoming increasingly serious. In the process of submarine pipeline gathering and transportation, it is necessary to add corrosion inhibitors and fungicides to inhibit under-scale corrosion. At present, the corrosion inhibitors and fungicides that inhibit under-scale corrosion at home and abroad mainly include: imidazoline quaternary ammonium salts, imidazoline derivatives, quinoline quaternary ammonium salts, pyridinium quaternary ammonium salts, etc. However, because imidazoline corrosion inhibitors with good corrosion inhibition effects usually contain long chains, their penetration effect is poor, resulting in poor inhibition of under-scale corrosion. The scale layer is generally negatively charged, so the loss of cationic corrosion inhibitors is large, which also leads to poor inhibition of under-scale corrosion. Therefore, anionic corrosion inhibitors and fungicides are more suitable for inhibiting under-scale corrosion of submarine pipelines, but conventional products of this type have poor corrosion inhibition and fungicidal effects, and poor water solubility, which cannot meet the needs of use. Summary of the Invention

[0003] To address the above-mentioned technical problems, the present invention provides a corrosion inhibitor and bactericide for inhibiting subscale corrosion of submarine pipelines and a preparation method. This corrosion inhibitor and bactericide targets subscale corrosion and bacteria in offshore oilfield submarine pipelines, offering more efficient corrosion inhibition and bactericidal effects. It features low dosage, good permeability, high corrosion inhibition, and high bactericidal rates, making it highly suitable for alleviating subscale corrosion and killing subscale bacteria in submarine pipelines.

[0004] In a first aspect, the present invention provides a method for preparing a corrosion inhibitor and bactericide for inhibiting under-scale corrosion of marine pipes, which is achieved by adopting the following technical solutions.

[0005] A method for preparing a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of a submarine pipeline comprises the following steps:

[0006] S1. Mix aminopyridine and aminoquinoline in a molar ratio of 1:2-2:1 and stir evenly;

[0007] S2. Slowly add dropwise a 50% mass concentration of an aqueous solution of aminopyridine and aminoquinoline hydroxide 2-2.5 times the total molar number;

[0008] S3. After the addition is complete, the temperature is lowered to below 30°C, and 1.5-2.0 times the total molar amount of aminopyridine and aminoquinoline in carbon disulfide is slowly added dropwise. The temperature during the entire addition process does not exceed 40°C.

[0009] S4. After the addition is complete, the reaction is continued at 20°C-40°C for 8-12 hours;

[0010] S5. Nitrogen is then bubbled in for 30-60 minutes to remove the remaining carbon disulfide to obtain intermediate A;

[0011] S6. Distilled water and a platinum complex catalyst were added, and the reaction was refluxed at 100-110 ℃ for 2-4 hours, and then 5-15% by mass of intermediate A of glutaraldehyde and 5-15% by mass of intermediate A of isothiazolinone was added, and the reaction was continued at reflux for 2-4 hours;

[0012] S7. Cooling to below 60° C., adding 5-10% by weight of the intermediate A sulfur-containing compound and 5-10% by weight of the intermediate A low molecular weight alcohol, stirring and dissolving uniformly to obtain a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of submarine pipelines.

[0013] Specifically, in step S1, aminopyridine includes 2-aminopyridine, 3-aminopyridine, and 4-aminopyridine; aminoquinoline includes 2-aminoquinoline, 3-aminoquinoline, 4-aminoquinoline, 5-aminoquinoline, 7-aminoquinoline, and 8-aminoquinoline.

[0014] Furthermore, in step S2, the hydroxide is sodium hydroxide or potassium hydroxide.

[0015] Furthermore, in step S6, the amount of distilled water added is equal to the mass of intermediate A.

[0016] Furthermore, in step S6, the amount of the complex platinum catalyst added is 0.3 to 0.5 percent of the mass of the intermediate A.

[0017] Furthermore, in step S7, the sulfur-containing compound is selected from thiourea, mercaptoethanol or ammonium thioglycolate.

[0018] Furthermore, in step S7, the low molecular alcohol is selected from methanol, ethanol or isopropanol.

[0019] In a second aspect, the present invention provides a corrosion inhibitor and bactericide for inhibiting under-scale corrosion of marine pipes, which is achieved by adopting the following technical solution.

[0020] A corrosion inhibitor and bactericide for inhibiting under-scale corrosion of marine pipes prepared by the above preparation method.

[0021] This application has the following beneficial effects.

[0022] The present invention addresses the on-site operating conditions of offshore oil fields and the characteristics of subscale corrosion in submarine pipelines by developing a product using a highly water-soluble anionic polymer of pyridine and quinoline as the main corrosion-inhibiting and sterilizing agent. Quinoline and pyridine form a water-soluble polymer during the azeotropic process, significantly improving the corrosion-inhibiting and sterilizing effects of the product. Furthermore, the product is anionic and contains no long chains, so it experiences minimal loss through the scale layer, significantly increasing the effective concentration of the permeating agent. Furthermore, when compounded with components exhibiting excellent subscale sterilization properties and synergistic effects, such as glutaraldehyde, isothiazolinone, and sulfur-containing compounds, the subscale corrosion inhibition and sterilization effects are further enhanced, thereby effectively reducing the dosage concentration. Therefore, the product of the present invention is highly suitable for inhibiting subscale corrosion in offshore oil fields and killing subscale bacteria. DETAILED DESCRIPTION

[0023] The present patent application is further described below with reference to the embodiments.

[0024] The materials used in the preparation processes of the following examples were not further processed unless otherwise specified and were purchased from commercial sources.

[0025] The complex platinum catalyst used in the following examples of this application was purchased from Tianjin Huibang Tongcheng Technology Development Co., Ltd., model HB-55.

[0026] Example 1

[0027] A method for preparing a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of a submarine pipeline comprises the following steps:

[0028] (1) First, 94.12 g of 2-aminopyridine (1 mol) and 288.34 g of 8-aminoquinoline (2 mol) were added to a reaction vessel and stirred to mix uniformly;

[0029] (2) Slowly add 600 g of sodium hydroxide (2.5 times) in a 50 wt% aqueous solution dropwise over 1 hour;

[0030] (3) After the addition is complete, cool to below 30°C and slowly add 152.28 g of carbon disulfide (2 times). The temperature during the entire addition process does not exceed 40°C, and the addition is completed within 3 hours.

[0031] (4) After the addition is complete, the mixture is reacted at 30°C for 10 hours;

[0032] (5) Nitrogen was bubbled in for another 30 minutes to remove the residual carbon disulfide to obtain intermediate A1;

[0033] (6) 1134.74 g of distilled water and 0.03 g of complex platinum catalyst (0.03 parts per million) were added, and the mixture was refluxed at 100-110° C. for 4 hours. 56.74 g of glutaraldehyde (5%) and 170.21 g of isothiazolinone (15%) were added, and the mixture was refluxed for 2 hours.

[0034] (7) Cooling to below 60° C., adding 56.74 g of mercaptoethanol (5%) and 56.74 g of methanol (5%), stirring and dissolving uniformly to obtain a corrosion inhibitor B1 for inhibiting under-scale corrosion of marine pipes.

[0035] Example 2

[0036] A method for preparing a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of a submarine pipeline comprises the following steps:

[0037] (1) First, 188.24 g of 3-aminopyridine (2 mol) and 144.17 g of 4-aminoquinoline (1 mol) were added to a reaction vessel and stirred to mix uniformly;

[0038] (2) Slowly add 480 g of a 50 wt% aqueous solution of sodium hydroxide (2 times) dropwise over 1 hour;

[0039] (3) After the addition is complete, cool to below 30°C and slowly add 114.21 g of carbon disulfide (1.5 times). The temperature does not exceed 40°C during the entire addition process, and the addition is completed within 3 hours.

[0040] (4) After the addition is complete, the mixture is reacted at 40°C for 8 hours;

[0041] (5) Nitrogen was bubbled in for another 30 minutes to remove the residual carbon disulfide to obtain intermediate A2;

[0042] (6) 926.62 g of distilled water and 0.05 g of complex platinum catalyst (0.05 parts per million) were added, and the mixture was refluxed at 100-110° C. for 2 hours. 138.99 g of glutaraldehyde (15%) and 46.33 g of isothiazolinone (5%) were added, and the mixture was refluxed for another 4 hours.

[0043] (7) Cooling to below 60° C., adding 92.66 g of thiourea (10%) and 92.66 g of ethanol (10%), stirring and dissolving uniformly to obtain a corrosion inhibitor B2 for inhibiting under-scale corrosion of marine pipes.

[0044] Example 3

[0045] A method for preparing a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of a submarine pipeline comprises the following steps:

[0046] (1) First, 141.18 g of 4-aminopyridine (1.5 mol) and 216.26 g of 5-aminoquinoline (1.5 mol) were added to a reaction vessel and stirred to mix uniformly;

[0047] (2) Slowly add 600 g of sodium hydroxide (2.5 times) in a 50 wt% aqueous solution dropwise over 1 hour;

[0048] (3) After the addition is complete, cool to below 30°C and slowly add 152.28 g of carbon disulfide (2 times). The temperature during the entire addition process does not exceed 40°C, and the addition is completed within 3 hours.

[0049] (4) After the addition is complete, the mixture is reacted at 20°C for 12 hours;

[0050] (5) Nitrogen was bubbled in for another 30 minutes to remove the residual carbon disulfide to obtain intermediate A3;

[0051] (6) 1109.72 g of distilled water and 0.04 g of complex platinum catalyst (0.04 parts per million) were added, and the mixture was refluxed at 100-110° C. for 2 hours. 110.97 g of glutaraldehyde (10%) and 110.97 g of isothiazolinone (10%) were added, and the mixture was refluxed for another 4 hours.

[0052] (7) Cooling to below 60° C., adding 55.49 g of ammonium thioglycolate (5%) and 110.97 g of isopropyl alcohol (10%), stirring and dissolving uniformly to obtain a corrosion inhibitor B3 for inhibiting under-scale corrosion of marine pipes.

[0053] Performance test 1

[0054] Experimental materials: mixed injection water from an offshore oil field, blank SRB bacteria content of 10 2 pcs / mL

[0055] Corrosion inhibition effect evaluation method: pre-scaling for 6 hours, dynamic high temperature autoclave, saturated carbon dioxide

[0056] Corrosion test time: 72h

[0057] Evaluation method of bactericidal effect: extinction dilution method

[0058] Experimental temperature: 60℃

[0059] Drug concentration: 50mg / L

[0060] The test results are as follows:

[0061] Table 1 Corrosion test results

[0062]

[0063]

[0064] Table 2 Bactericidal effect test results

[0065]

[0066] Performance test 2

[0067] Experimental materials: wastewater from an offshore oil field, blank SRB bacteria content of 104 pcs / mL

[0068] Corrosion inhibition effect evaluation method: Pre-scaling for 6 hours, dynamic high temperature autoclave, 0.2MPa carbon dioxide corrosion test time: 72 hours

[0069] Evaluation method of bactericidal effect: extinction dilution method

[0070] Experimental temperature: 80℃

[0071] Drug concentration: 60mg / L

[0072] The test results are as follows:

[0073] Table 3 Corrosion test results

[0074] Serial number corrosion inhibitors Corrosion rate (mm / a) Corrosion inhibition efficiency (%) 1 Without corrosion inhibitor (with scale) 0.3033 - 2 Thiourea imidazoline 0.2033 32.97 3 Imidazoline quaternary ammonium salt 0.1700 43.95 4 Quinoline quaternary ammonium salt 0.1521 49.85 5 Pyridinium quaternary ammonium salt 0.1881 37.98 6 Corrosion inhibitor and fungicide B1 0.0606 80.02 7 Corrosion inhibitor and fungicide B2 0.0601 80.18 8 Corrosion inhibitor B3 0.0539 82.23

[0075] Table 4 Bactericidal effect test results

[0076]

[0077] It can be seen from the above test data that the present invention has a more efficient wax prevention and pour point reduction effect on both light and medium-weight offshore waxy crude oils.

[0078] The embodiments of this specific implementation method are all preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.

Claims

1. A method for preparing a corrosion inhibitor and bactericide for inhibiting under-scale corrosion of marine pipelines, characterized by: The following steps are involved: S1. Mix aminopyridine and aminoquinoline in a molar ratio of 1:2-2:1 and stir evenly; S2. Slowly add dropwise a 50% mass concentration of an aqueous solution of aminopyridine and aminoquinoline hydroxide 2-2.5 times the total molar number; S3. After the addition is complete, the temperature is lowered to below 30°C, and 1.5-2.0 times the total molar amount of aminopyridine and aminoquinoline in carbon disulfide is slowly added dropwise. The temperature during the entire addition process does not exceed 40°C. S4. After the addition is complete, the reaction is continued at 20°C-40°C for 8-12 hours; S5. Nitrogen is then bubbled in for 30-60 minutes to remove the remaining carbon disulfide to obtain intermediate A; S6. Distilled water and a platinum complex catalyst were added, and the reaction was refluxed at 100-110 ℃ for 2-4 hours, and then 5-15% by mass of intermediate A of glutaraldehyde and 5-15% by mass of intermediate A of isothiazolinone was added, and the reaction was continued at reflux for 2-4 hours; S7. Cooling to below 60° C., adding 5-10% by weight of the intermediate A sulfur-containing compound and 5-10% by weight of the intermediate A low molecular weight alcohol, stirring and dissolving uniformly to obtain a corrosion inhibitor and fungicide for inhibiting under-scale corrosion of submarine pipelines.

2. The method for preparing a corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes according to claim 1, characterized in that: In step S2, the hydroxide is sodium hydroxide or potassium hydroxide.

3. The method for preparing a corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes according to claim 1, characterized in that: In step S6, the amount of distilled water added is equal to the mass of intermediate A.

4. The method for preparing a corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes according to claim 1, characterized in that: In step S6, the amount of the complex platinum catalyst added is 0.3 to 0.5 of the mass of the intermediate A.

5. The method for preparing a corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes according to claim 1, characterized in that: In step S7, the sulfur-containing compound is selected from thiourea, mercaptoethanol or ammonium thioglycolate.

6. The method for preparing a corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes according to claim 1, characterized in that: In step S7, the low molecular alcohol is selected from methanol, ethanol or isopropanol.

7. A corrosion inhibitor and bactericide for inhibiting underscale corrosion of marine pipes prepared by the preparation method according to any one of claims 1 to 6.

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