A bactericidal corrosion inhibitor for oilfield mixed transportation pipelines in the sea and its preparation method

Abstract

The present application discloses a bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipelines and a preparation method thereof. The steps are as follows: Stir and mix halogenated alkyl hydantoin, aromatic amine, organic amide solvent and iodide, and react at 120 - 150 °C for 8 - 12 h; Cool down and drop - wise add epichlorohydrin, and continue to react at 15 - 40 °C for 8 - 12 h after the dropping is completed; Add mercaptobenzothiazole and potassium hydroxide, evacuate and heat up to 95 - 105 °C, introduce ethylene oxide, and continue to react for more than 5 h, then heat up to 140 - 160 °C and continue to react until the pressure drops to negative pressure and then cool down to room temperature; Add low - molecular - weight polyethylene glycol, 2,2 - dibromo - 3 - nitrilopropionamide, water, thiourea and thiocyanate, and dissolve to obtain the bactericidal corrosion inhibitor. This bactericidal corrosion inhibitor has good inhibitory effects on corrosion and SRB bacteria in the medium, with a sterilization rate greater than 99% and an inhibition rate greater than 90%. It has good compatibility, a small dosage, and a high bactericidal and corrosion - inhibition rate.

Description

Technical Field

[0001] This application relates to the technical field of chemical sterilization and corrosion inhibition, and particularly to a bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines and a preparation method thereof. Background Art

[0002] At present, there are relatively serious corrosion and bacterial growth problems in mixed - transportation submarine pipelines, causing huge economic losses. Adding chemical agents can effectively and economically control corrosion problems and bacterial growth. However, in order to increase production, methods such as injecting polymers or thermal recovery are usually adopted. In these processes, acrylamide polymers are usually added to improve oil recovery and scale inhibitor dispersants are added to relieve scale formation. Acrylamide polymers and scale inhibitor dispersants are basically anionic polymers, which are returned with the produced fluid and will greatly reduce the effects of common corrosion inhibitors and bactericides during the mixed - transportation process. To solve the above problems, it is of great significance to prepare a bactericidal corrosion inhibitor with excellent bactericidal and corrosion - inhibition performance and good compatibility, which can well control corrosion and bacterial growth problems during the mixed - transportation process of such oilfield produced fluids and sewage. Summary of the Invention

[0003] To solve the above - mentioned technical problems, this application provides a bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines and a preparation method thereof. This bactericide can effectively kill oilfield bacteria, has the characteristics of good compatibility, small dosage, and high bactericidal and corrosion - inhibition rate, and is very suitable for controlling corrosion and bacteria in the mixed - transportation submarine pipelines of oilfields, especially offshore oilfields.

[0004] In the first aspect, this application provides a preparation method of a bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines, which is realized by the following technical solutions.

[0005] A preparation method of a bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines includes the following steps:

[0006] S1. Stir and mix haloalkyl hydantoin, aromatic amine, organic amide solvent and iodide, and react at 120 °C - 150 °C for 8 - 12 hours; the molar ratio of haloalkyl hydantoin to aromatic amine is (0.9 - 1.1):1;

[0007] S2. Cool down to below 30 °C, dropwise add epichlorohydrin, control the temperature not exceeding 40 °C, and the molar ratio of epichlorohydrin to aromatic amine is (1 - 1.2):1; after the dropwise addition is completed, continue to react at 15 °C - 40 °C for 8 - 12 hours;

[0008] S3. Add mercaptobenzothiazole and potassium hydroxide to the reaction product of step S2. The molar ratio of mercaptobenzothiazole to aromatic amine is (0.1 - 0.3):1. Vacuumize and heat up to 95 - 105 °C, then introduce ethylene oxide and control the temperature at 100 °C - 130 °C until it is completely introduced. The molar ratio of ethylene oxide to aromatic amine is (8 - 15):1. Continue the reaction for more than 5 hours, then heat up to 140 - 160 °C and continue the reaction until the pressure drops to negative pressure, and then cool down to room temperature.

[0009] S4. Add low molecular weight polyethylene glycol, 2,2 - dibromo - 3 - nitrilopropionamide (DBNPA), water, thiourea and thiocyanate to the reaction product of step S3, and dissolve to obtain a bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipelines.

[0010] Further, in step S1, the dosage of the organic amide solvent is 5 - 8 times the mass of the aromatic amine; the organic amide solvent is selected from one or a mixture of two of N,N - dimethylformamide (DMF) and N,N - dimethylacetamide (DMAC).

[0011] Further, in step S1, the dosage of the iodide is 0.5% - 1% of the mass of the aromatic amine; the iodide is selected from sodium iodide or potassium iodide.

[0012] Further, in step S1, the haloalkyl hydantoin is selected from chlorobutyl hydantoin or bromoethyl hydantoin.

[0013] Further, in step S1, the aromatic amine is selected from aniline or benzylamine.

[0014] Further, in step S3, the dosage of potassium hydroxide is 0.3% - 0.5% of the mass of the aromatic amine.

[0015] Further, in step S4, the low molecular weight polyethylene glycol is selected from one or a mixture of two of polyethylene glycol 200, polyethylene glycol 400, and polyethylene glycol 600; the dosage of the low molecular weight polyethylene glycol is 3 - 5 times the mass of the aromatic amine.

[0016] Further, in step S4, the thiocyanate is selected from sodium thiocyanate, ammonium thiocyanate or potassium thiocyanate; the dosage of the thiocyanate is 10% - 20% of the mass of the aromatic amine.

[0017] Further, in step S4, the dosage of 2,2 - dibromo - 3 - nitrilopropionamide is 10% - 20% of the mass of the aromatic amine; the dosage of water is 4 - 6 times the mass of the aromatic amine; the dosage of thiourea is 10% - 20% of the mass of the aromatic amine.

[0018] Second, this application provides a bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipelines, which is achieved by the following technical solutions.

[0019] A bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines prepared by the above - mentioned preparation method.

[0020] This application has the following beneficial effects.

[0021] In view of the problem that the performance of cationic corrosion inhibitors and bactericides is significantly reduced due to the presence of anionic polyacrylamide and scale and dispersion inhibitors in the medium of the mixed - transportation submarine pipeline, the present invention has developed a new type of bactericidal corrosion inhibitor for mixed - transportation submarine pipelines. It has good inhibitory effects on corrosion and SRB bacteria in the medium, with a bactericidal rate greater than 99% and a corrosion inhibition rate greater than 90%. It has the characteristics of good compatibility, small dosage, and high bactericidal and corrosion inhibition rates. Detailed implementation manners

[0022] The following further illustrates this patent application with reference to embodiments.

[0023] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; unless otherwise specified, the materials, reagents, etc. used in the following preparation examples and examples can all be obtained from commercial channels.

[0024] Example 1

[0025] A preparation method of a bactericidal corrosion inhibitor for oilfield mixed - transportation submarine pipelines includes the following steps:

[0026] Step 1: Add 171.56 g of chlorobutyl hydantoin (0.9 mol), 93.13 g of aniline (1 mol) into a closed pressure - resistant reaction vessel, then add 372.52 g of DMAC and 372.52 g of DMF, 0.46565 g of sodium iodide. Start stirring and heating up, and react at 120 °C for 12 hours.

[0027] Step 2: Cool down to a temperature below 30 °C by circulating water, slowly dropwise add 110.04 g of epichlorohydrin (1.2 mol), control the temperature not to exceed 40 °C. After dropping, continue to react at 40 °C for 8 hours.

[0028] Step 3: Add 16.73 g of mercaptobenzothiazole (0.1 mol), 0.27939 g of potassium hydroxide, evacuate for 5 minutes, then heat up to 95 °C, and slowly introduce 352.4 g of ethylene oxide (8 mol). Control the temperature to be within 100 °C - 130 °C during the introduction, and continue to react for more than 5 hours. Then heat up to 140 °C and continue to react until the pressure in the kettle drops to a negative pressure, and then cool down to room temperature.

[0029] Step 4: Add 279.39 g of polyethylene glycol 200 and 9.313 g of DBNPA into the reaction vessel. After stirring and dissolving them evenly, add 558.78 g of distilled water, 9.313 g of thiourea, and 18.626 g of sodium thiocyanate, and stir to dissolve evenly to obtain the bactericidal and corrosion inhibitor A1 for mixed - transportation submarine pipelines.

[0030] Example 2

[0031] A preparation method of a bactericidal and corrosion inhibitor for oil - field mixed - transportation submarine pipelines includes the following steps:

[0032] Step 1: Add 227.73 g of bromoethyl hydantoin (1.1 mol) and 107.15 g of benzylamine (1 mol) into a closed pressure - resistant reaction vessel. Then add 535.75 g of DMF and 1.07 g of potassium iodide. Start stirring and heating, and react at 150 °C for 8 hours.

[0033] Step 2: Pass circulating water to cool down to a temperature below 30 °C, and slowly dropwise add 101.78 g of epichlorohydrin (1.1 mol), controlling the temperature not to exceed 40 °C. After dropping, continue to react at 15 °C for 12 hours.

[0034] Step 3: Add 50.19 g of mercaptobenzothiazole (0.3 mol) and 0.53575 g of potassium hydroxide, evacuate for 5 minutes, then heat up to 100 °C, and slowly introduce 660.75 g of ethylene oxide (15 mol). Control the temperature to finish passing through at 100 °C - 130 °C, and continue to react for more than 5 hours. Then heat up to 150 °C and continue to react until the pressure in the kettle drops to a negative pressure, and then cool down to room temperature.

[0035] Step 4: Add 535.75 g of polyethylene glycol 400 and 21.43 g of DBNPA into the reaction vessel. After stirring and dissolving them evenly, add 428.60 g of distilled water, 21.43 g of thiourea, and 10.715 g of sodium thiocyanate, and stir to dissolve evenly to obtain the bactericidal and corrosion inhibitor A2 for mixed - transportation submarine pipelines.

[0036] Example 3

[0037] A preparation method of a bactericidal and corrosion inhibitor for oil - field mixed - transportation submarine pipelines includes the following steps:

[0038] Step 1: Add 190.63 g of chlorobutyl hydantoin (1 mol) and 107.15 g of benzylamine (1 mol) into a closed pressure - resistant reaction vessel. Then add 535.75 g of DMF and 107.15 g of DMAC, and 8.57 g of potassium iodide. Start stirring and heating, and react at 140 °C for 10 hours.

[0039] Step 2: Cool down to a temperature below 30°C by circulating water, slowly add 92.53 g of epichlorohydrin (1 mol), control the temperature not to exceed 40°C. After the addition, continue the reaction at 20°C for 10 hours;

[0040] Step 3: Add 33.45 g of mercaptobenzothiazole (0.2 mol), 0.4286 g of potassium hydroxide, evacuate for 5 minutes, then heat up to 105°C, and slowly introduce 440.50 g of ethylene oxide (10 mol). Control the temperature to be within 100°C - 130°C during the introduction, and continue the reaction for more than 5 hours. Then heat up to 160°C and continue the reaction until the pressure in the kettle drops to a negative pressure, and then cool down to room temperature;

[0041] Step 4: Add 321.45 g of polyethylene glycol 200, 214.30 g of polyethylene glycol 600, and 16.07 g of DBNPA into the reaction vessel. After stirring and dissolving evenly, add 535.75 g of distilled water, 16.07 g of thiourea, and 16.07 g of sodium thiocyanate, and stir to dissolve evenly to obtain the bactericidal and corrosion inhibitor A3 for mixed transportation of seawater pipelines.

[0042] Example 4

[0043] A preparation method of a bactericidal and corrosion inhibitor for oilfield mixed transportation of seawater pipelines, comprising the following steps:

[0044] Step 1: Add 207.03 g of bromoethyl hydantoin (1 mol) and 93.13 g of aniline (1 mol) into a closed pressure-resistant reaction vessel, then add 465.65 g of DMF, 186.26 g of DMAC, and 9 g of potassium iodide. Start stirring and heat up, and react at 130°C for 11 hours;

[0045] Step 2: Cool down to a temperature below 30°C by circulating water, slowly add 101.78 g of epichlorohydrin (1.1 mol), control the temperature not to exceed 40°C. After the addition, continue the reaction at 30°C for 9 hours;

[0046] Step 3: Add 33.45 g of mercaptobenzothiazole (0.2 mol), 0.40 g of potassium hydroxide, evacuate for 5 minutes, then heat up to 100°C, and slowly introduce 528.60 g of ethylene oxide (12 mol). Control the temperature to be within 100°C - 130°C during the introduction, and continue the reaction for more than 5 hours. Then heat up to 150°C and continue the reaction until the pressure in the kettle drops to a negative pressure, and then cool down to room temperature;

[0047] Step 4: Add 190.00 g of polyethylene glycol 200, 180.00 g of polyethylene glycol 400, and 15.00 g of DBNPA into the reaction vessel. After stirring and dissolving them evenly, add 535.75 g of distilled water, 10.00 g of thiourea, and 18.00 g of sodium thiocyanate, and stir to dissolve evenly to obtain the bactericidal and corrosion inhibitor A4 for mixed transportation pipelines in the sea.

[0048] Application Example 1

[0049] Experimental raw material: Produced fluid containing polymers from an offshore oilfield, with the content of blank SRB bacteria being 1.2×10 3 cells / mL

[0050] Evaluation method: Extinction dilution method

[0051] Experimental temperature: 80 °C

[0052] Test time: 168 h

[0053] Concentration of the agent: 30 mg / L

[0054] The test results are as follows:

[0055] Table 1 Results of bactericidal experiment

[0056]

[0057] Application Example 2

[0058] Experimental raw material: Produced sewage with anionic polymer scale inhibitor added from an offshore oilfield, with the content of blank SRB bacteria being 0.9×10 6 cells / mL

[0059] Evaluation method: Extinction dilution method

[0060] Experimental temperature: 60 °C

[0061] Test time: 168 h

[0062] Concentration of the agent: 60 mg / L

[0063] The test results are as follows:

[0064] Table 2 Results of bactericidal experiment

[0065]

[0066] It can be seen from the above detection data that the present invention has a good inhibitory effect on SRB bacteria in the produced sewage with anionic polymer scale inhibitor added from an offshore oilfield, and the bactericidal rate is greater than 99%, which is significantly better than the commonly used oilfield bactericides.

[0067] Application Example 3

[0068] Experimental medium: Polymer-containing produced fluid from an offshore oilfield Evaluation method: Dynamic corrosion experiment in a 3-L Hastelloy steel autoclave indoors Experimental material: 20# steel

[0069] Experimental temperature: 80°C

[0070] Medium flow rate: 1.0 m / s

[0071] Experimental gas composition: 0.25 MPa CO 2 + 0.7 MPa N 2

[0072] Test time: 72 hours for indoor experiment

[0073] Agent concentration: 30 mg / L

[0074] Test results are as follows:

[0075] Table 3 Results of indoor dynamic corrosion test

[0076]

[0077] Application Example 4

[0078] Experimental medium: Produced sewage with anionic polymer scale inhibitor added from an offshore oilfield

[0079] Evaluation method: Dynamic corrosion experiment in a 3-L Hastelloy steel autoclave indoors

[0080] Experimental material: Q235 steel

[0081] Experimental temperature: 60°C

[0082] Medium flow rate: 1.2 m / s

[0083] Experimental gas composition: 0.20 MPa CO 2 + 0.50 MPa N 2

[0084] Test time: 72 hours for indoor experiment

[0085] Agent concentration: 20 mg / L

[0086] Test results are as follows:

[0087] Table 4 Indoor dynamic corrosion results

[0088]

[0089] It can be seen from the above detection data that for the polymer-containing produced fluid from the oilfield and the produced sewage with anionic polymer scale inhibitor added, compared with various commonly used corrosion inhibitors such as organic phosphines and heterocyclic compounds, the bactericidal corrosion inhibitor of the present invention has a more efficient corrosion inhibition effect.

[0090] The embodiments of this specific implementation manner are all preferred embodiments of this application, and do not limit the protection scope of this application accordingly. Therefore, all equivalent changes made according to the structure, shape, and principle of this application shall be covered within the protection scope of this application.

Claims

1. Preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline Characterized in that: It includes the following steps: S1. Stir and mix halogenated alkyl hydantoin, aromatic amine, organic amide solvent and iodide, and react at 120°C - 150°C for 8 - 12 hours; the molar ratio of halogenated alkyl hydantoin to aromatic amine is (0.9 - 1.1):1; S2. Cool down to below 30°C, dropwise add epichlorohydrin, control the temperature not exceeding 40°C, and the molar ratio of epichlorohydrin to aromatic amine is (1 - 1.2):1; after dropping, continue to react at 15°C - 40°C for 8 - 12 hours; S3. Add mercaptobenzothiazole and potassium hydroxide to the reaction product of step S2, and the molar ratio of mercaptobenzothiazole to aromatic amine is (0.1 - 0.3):1; evacuate and heat up to 95 - 105°C, introduce ethylene oxide, control the temperature to finish passing through at 100°C - 130°C, and the molar ratio of ethylene oxide to aromatic amine is (8 - 15):1; continue to react for more than 5 hours, then heat up to 140 - 160°C and continue to react until the pressure drops to negative pressure, and then cool down to room temperature; S4. Add low - molecular - weight polyethylene glycol, 2,2 - dibromo - 3 - nitrilopropionamide, water, thiourea and thiocyanate to the reaction product of step S3, and dissolve to obtain the bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline.

2. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S1, the dosage of the organic amide solvent is 5 - 8 times the mass of the aromatic amine; the organic amide solvent is selected from one or a mixture of two of N,N - dimethylformamide and N,N - dimethylacetamide.

3. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S1, the dosage of the iodide is 0.5% - 1% of the mass of the aromatic amine; the iodide is selected from sodium iodide or potassium iodide.

4. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S1, the halogenated alkyl hydantoin is selected from chlorobutyl hydantoin or bromoethyl hydantoin.

5. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S1, the aromatic amine is selected from aniline or benzylamine.

6. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S3, the dosage of potassium hydroxide is 0.3% - 0.5% of the mass of the aromatic amine.

7. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S4, the low - molecular - weight polyethylene glycol is selected from one or a mixture of two of polyethylene glycol 200, polyethylene glycol 400 and polyethylene glycol 600; the dosage of the low - molecular - weight polyethylene glycol is 3 - 5 times the mass of the aromatic amine.

8. The preparation method of bactericidal corrosion inhibitor for oilfield mixed - transportation seawater pipeline according to claim 1, Characterized in that: In step S4, the thiocyanate is selected from sodium thiocyanate, ammonium thiocyanate or potassium thiocyanate; the dosage of the thiocyanate is 10%-20% of the mass of the aromatic amine.

9. The preparation method of a bactericidal corrosion inhibitor for oilfield mixed transportation seawater pipelines according to claim 1, characterized in that: In step S4, the dosage of 2,2-dibromo-3-nitrilopropionamide is 10%-20% of the mass of the aromatic amine; the dosage of water is 4-6 times the mass of the aromatic amine; the dosage of thiourea is 10%-20% of the mass of the aromatic amine.

10. A bactericidal corrosion inhibitor for oilfield mixed transportation seawater pipelines prepared by the preparation method according to any one of claims 1-9.

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