Five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor
By using the five-fingered doimidazoline quaternary ammonium corrosion inhibitor, the corrosion control problem in the hydrogen sulfide/carbon dioxide system was solved, and stronger metal corrosion resistance and more effective corrosion inhibition effect were achieved.
Patent Information
- Application Number
- CN202411565167.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-05
- Publication Date
- 2025-02-18
AI Technical Summary
The prior art is difficult to effectively control corrosion in the hydrogen sulfide/carbon dioxide system, resulting in serious corrosion problems in petrochemical equipment and pipelines.
The five-fingered doimidazoline quaternary ammonium salt is used as the corrosion inhibitor to increase the metal surface adsorption capacity through the multi-quaternary ammonium salt, improve the film formation strength, and prevent corrosive ions from approaching the metal through the hydrophobic base of the multi-hexadecimal carbon chain and the eighteen-carbon chain. surface.
It significantly improves the corrosion inhibition effect in the hydrogen sulfide/carbon dioxide system, enhances the corrosion resistance of metals, and prevents the diffusion of corrosive ions and sulfurized corrosion products.
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Figure BDA0005119023890000081
Abstract
Description
Technical Field
[0001] The invention relates to the technical field of oilfield chemicals, in particular to a five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor. Background Art
[0002] With the continuous increase of sulfur-containing oil and gas fields in recent years, petrochemical equipment and pipelines are facing serious H2S corrosion. Although there are a large number of literatures and patents reporting on anti-H2S corrosion inhibitors, the corrosion control effect under H2S and CO2 is not good. Therefore, it is of great significance to propose a new corrosion inhibitor for hydrogen sulfide / carbon dioxide system in view of the corrosion inhibition performance problem in hydrogen sulfide / carbon dioxide system. Summary of the invention
[0003] In order to solve the above technical problems, the present invention provides a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor. The present invention increases the metal surface adsorption capacity through multiple quaternary ammonium salts, thereby improving the film-forming strength of the corrosion inhibitor; through multiple hexadecene and octadecene carbon chain hydrophobic groups, corrosive ions are prevented from approaching the metal surface through the aqueous solution, thereby improving the corrosion inhibition effect in the hydrogen sulfide / carbon dioxide system.
[0004] The present invention is achieved by adopting the following technical solutions.
[0005] A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following components in mass percentage: 10-30% of five-finger polyimidazoline quaternary ammonium salt, 1-10% of OP-10, 1-10% of mercaptoethanol, 1-10% of thiourea, 10%-15% of alcohol solvent, and the balance is deionized water;
[0006] The preparation method of the five-finger polyimidazoline quaternary ammonium salt comprises the following steps: synthesizing the five-finger polyimidazoline with organic acid and organic amine, and then modifying the five-finger polyimidazoline quaternary ammonium salt with quaternizing agents alkyl halide and dimethyl carbonate.
[0007] Further, the synthesis method of the five-finger-shaped polyimidazoline is as follows:
[0008] Under nitrogen protection, add a benzene water-carrying agent to diethylenetriaminepentaacetic acid, and under stirring, drop diethylenetriamine in an ice-water bath for 0.5 to 2 hours, and react by stirring for 1 to 2 hours; change to an oil bath, slowly heat up to 140°C to 160°C, and reflux for 1 to 6 hours to separate the water generated by the amidation reaction; then slowly heat up to 160°C to 220°C and keep warm for 1 to 4 hours to separate the water generated by the imidazoline ring formation, and evaporate the solvent and unreacted raw materials, and then cool to room temperature to obtain five-finger polyimidazole.
[0009] Furthermore, the molar ratio of diethylenetriaminepentaacetic acid to diethylenetriamine is 1:5-6.
[0010] Furthermore, the mass ratio of diethylenetriaminepentaacetic acid to benzene water-carrying agent is 1:0.1-0.5.
[0011] Furthermore, the benzene-based water-carrying agent is toluene and / or xylene.
[0012] Further, the synthesis method of the five-finger polyimidazoline quaternary ammonium salt is as follows:
[0013] Under nitrogen protection, stirring and 60°C to 80°C, a quaternary ammonium alkyl halide is added dropwise to the five-finger-shaped polyimidazoline, and the addition time is controlled within 0.5 to 1 h; the temperature is slowly raised to 120°C to 150°C, and the reaction is stirred for 2 to 6 h. After the reaction is completed, the temperature is lowered; and under stirring and 30°C to 50°C, a quaternary ammonium dimethyl carbonate is added dropwise, and the addition time is controlled within 0.5 to 1 h; the temperature is slowly raised to 70°C to 120°C, and the reaction is stirred for 4 to 8 h. The solvent is evaporated under reduced pressure to obtain a five-finger-shaped polyimidazoline quaternary ammonium salt.
[0014] Furthermore, the molar ratio of the five-finger polyimidazoline to the quaternary ammonium reagent alkyl halide is 1:1 to 3.2.
[0015] Furthermore, the molar ratio of the five-finger polyimidazoline to the quaternizing agent dimethyl carbonate is 1:2 to 4.2.
[0016] Furthermore, the quaternary ammonium agent alkyl halide includes hexadecane chloride, hexadecane bromide, octadecane chloride, and octadecane bromide.
[0017] Furthermore, the alcohol solvent is selected from one or more of methanol, ethanol, and ethylene glycol.
[0018] This application has the following beneficial effects.
[0019] This patent effectively solves the corrosion inhibition performance problem in the hydrogen sulfide / carbon dioxide system and forms a five-finger polyimidazoline quaternary ammonium salt formula system. The corrosion inhibitor has multiple imidazoline rings and multiple cationic adsorption centers, and has a large number of electron clouds densely adsorbed on the metal surface, which improves the energy barrier of metal corrosion resistance and improves the chemical adsorption film strength; the two quaternization reactions increase the hexadecene and octadecene chain hydrophobic groups and cationic degree of the corrosion inhibitor, which not only prevents corrosive ions from approaching the metal surface through the aqueous solution, but also prevents the corrosion reaction of the sulfide corrosion product iron ions from diffusing into the solution. DETAILED DESCRIPTION
[0020] The present patent application is further described below in conjunction with embodiments.
[0021] Example 1
[0022] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0023] Step 1: Synthesis of five-finger polyimidazolines
[0024] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:5; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry toluene solvent to the reactor at the same time, the mass ratio of the reactant to the benzene water-carrying agent is 1:0.15; turn on the stirring, add diethylenetriamine dropwise in an ice water bath, the dropping time is 1 hour, and stir the reaction for 2 hours; change the oil bath, heat up and reflux at 140°C for 4 hours, and separate the water generated by the amidation reaction; then gradually and slowly heat up to 200°C and keep warm for 1 hour, separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0025] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0026] Under nitrogen protection, add the five-finger polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel, and a condenser, add the quaternary ammonium chloride hexadecane to the constant pressure dropping funnel, and the molar ratio of the five-finger polyimidazoline intermediate to the quaternary ammonium chloride hexadecane is 1:2; turn on the mechanical stirring, and add the quaternary ammonium chloride hexadecane to the reactor at 70°C, and the dropping time is controlled at 0.5h; slowly heat up to 120°C, The mixture was stirred and reacted for 6 hours. After the reaction was completed, the temperature was lowered to 20°C, and the quaternary ammonium reagent dimethyl carbonate was added to the constant pressure dropping funnel. The molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent dimethyl carbonate was 1:3. The mechanical stirring was turned on, and the quaternary ammonium reagent dimethyl carbonate was added dropwise to the reactor at 40°C. The dropping time was controlled within 1 hour. The temperature was slowly raised to 90°C, and the mixture was stirred and reacted for 8 hours. The solvent was evaporated under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0027] Step 3: The five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of methanol is 10%, and the rest is deionized water.
[0028] Example 2
[0029] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0030] Step 1: Synthesis of five-finger polyimidazolines
[0031] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:5.2; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry xylene solvent to the reactor at the same time, the mass ratio of the reactant to the benzene water-carrying agent is 1:0.2; turn on the stirring, add diethylenetriamine dropwise in an ice water bath, the dropping time is 1 hour, and stir the reaction for 1 hour; change the oil bath, slowly heat up to 150°C and reflux for 4 hours to separate the water generated by the amidation reaction; then slowly heat up to 220°C and keep warm for 2 hours to separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0032] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0033] Under nitrogen protection, add the five-finger-shaped polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel and a condenser, add the quaternizing agent octadecane chloride to the constant pressure dropping funnel, and the molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternizing agent octadecane chloride is 1:2; turn on the mechanical stirring, and at 60°C, drop the quaternizing agent octadecane chloride into the reactor, and the dropping time is controlled within 1 hour; slowly heat up to 120°C, and stir to react for 6 hours; after the reaction is completed, cool to 40°C, add the quaternizing agent dimethyl carbonate into the constant pressure dropping funnel, and the molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternizing agent dimethyl carbonate is 1:3, turn on the mechanical stirring, and at 50°C, drop the quaternizing agent dimethyl carbonate into the reactor, and the dropping time is controlled within 1 hour; slowly heat up to 80°C, stir to react for 8 hours, and evaporate the solvent under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0034] Step 3: The five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of ethanol is 15%, and the rest is deionized water.
[0035] Example 3
[0036] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0037] Step 1: Synthesis of five-finger polyimidazolines
[0038] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:5.4; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry toluene solvent to the reactor at the same time, the mass ratio of the reactant to the benzene water-carrying agent is 1:0.2; turn on the stirring, add diethylenetriamine dropwise in an ice water bath, the dropping time is 2 hours, and stir the reaction for 1.5 hours; change the oil bath, slowly heat up to 150°C and reflux for 4 hours to separate the water generated by the amidation reaction; then slowly heat up to 200°C and keep warm for 2 hours to separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0039] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0040] Under nitrogen protection, add the five-finger-shaped polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel, and a condenser, add the quaternary ammonium reagent octadecane bromide to the constant pressure dropping funnel, and the molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent octadecane bromide is 1:3; turn on the mechanical stirring, and at 70°C, drop the quaternary ammonium reagent octadecane bromide into the reactor, and the dropping time is controlled at 0.5h; slowly raise the temperature to 130°C, The mixture was stirred and reacted for 4 hours. After the reaction was completed, the temperature was lowered to 30°C, and the quaternary ammonium reagent dimethyl carbonate was added to the constant pressure dropping funnel. The molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent dimethyl carbonate was 1:2. The mechanical stirring was turned on, and the quaternary ammonium reagent dimethyl carbonate was added dropwise to the reactor at 30°C. The dropping time was controlled within 1 hour. The temperature was slowly raised to 100°C, and the mixture was stirred and reacted for 8 hours. The solvent was evaporated under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0041] Step 3: The five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger-shaped polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of methanol is 15%, and the rest is deionized water.
[0042] Example 4
[0043] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0044] Step 1: Synthesis of five-finger polyimidazolines
[0045] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:5.5; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry toluene solvent to the reactor at the same time, the mass ratio of the reactant to the benzene water-carrying agent is 1:0.3; turn on the stirring, add diethylenetriamine dropwise in an ice water bath, the dropping time is 2 hours, and stir the reaction for 1.5 hours; change the oil bath, slowly heat up to 160°C and reflux for 4 hours to separate the water generated by the amidation reaction; then slowly heat up to 200°C and keep warm for 4 hours to separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0046] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0047] Under nitrogen protection, add the five-finger polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel, and a condenser, add the quaternary ammonium reagent hexadecane bromide to the constant pressure dropping funnel, and the molar ratio of the five-finger polyimidazoline intermediate to the quaternary ammonium reagent hexadecane bromide is 1:3; turn on the mechanical stirring, and at 70°C, drop the quaternary ammonium reagent hexadecane bromide into the reactor, and the dropping time is controlled at 0.5h; slowly heat up to 130°C, The mixture was stirred and reacted for 4 hours. After the reaction was completed, the temperature was lowered to 30°C, and the quaternary ammonium reagent dimethyl carbonate was added to the constant pressure dropping funnel. The molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent dimethyl carbonate was 1:2. The mechanical stirring was turned on, and the quaternary ammonium reagent dimethyl carbonate was added dropwise to the reactor at 30°C. The dropping time was controlled within 1 hour. The temperature was slowly raised to 110°C, and the mixture was stirred and reacted for 8 hours. The solvent was evaporated under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0048] Step 3: The five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger-shaped polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of ethanol is 10%, and the rest is deionized water.
[0049] Example 5
[0050] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0051] Step 1: Synthesis of five-finger polyimidazolines
[0052] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:6; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry toluene solvent to the reactor at the same time, the mass ratio of the reactant to the benzene water-carrying agent is 1:0.18; turn on the stirring, add diethylenetriamine dropwise in an ice water bath, the dropping time is 2 hours, and stir the reaction for 1.5 hours; change the oil bath, slowly heat up to 150°C and reflux for 5 hours to separate the water generated by the amidation reaction; then slowly heat up to 210°C and keep warm for 4 hours to separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0053] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0054] Under nitrogen protection, add the five-finger polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel, and a condenser, add the quaternary ammonium chloride octadecane to the constant pressure dropping funnel, and the molar ratio of the five-finger polyimidazoline intermediate to the quaternary ammonium chloride octadecane is 1:1; turn on the mechanical stirring, and add the quaternary ammonium chloride octadecane to the reactor at 70°C, and the dropping time is controlled at 0.5h; slowly heat up to 140°C, The mixture was stirred and reacted for 4 hours. After the reaction was completed, the temperature was lowered to 30°C, and the quaternary ammonium reagent dimethyl carbonate was added to the constant pressure dropping funnel. The molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent dimethyl carbonate was 1:4. The mechanical stirring was turned on, and the quaternary ammonium reagent dimethyl carbonate was added dropwise to the reactor at 30°C. The dropping time was controlled within 1 hour. The temperature was slowly raised to 120°C, and the mixture was stirred and reacted for 8 hours. The solvent was evaporated under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0055] Step 3: The five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger-shaped polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of methanol is 12%, and the rest is deionized water.
[0056] Example 6
[0057] A method for preparing a five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor comprises the following steps:
[0058] Step 1: Synthesis of five-finger polyimidazolines
[0059] Accurately weigh the reactants diethylenetriamine pentaacetic acid and diethylenetriamine in sequence, with a molar ratio of 1:5.8; under nitrogen protection, add diethylenetriamine pentaacetic acid to a four-necked flask equipped with a thermometer, a stirrer, a condenser, a constant pressure dropping funnel and a water separator, add diethylenetriamine to the constant pressure dropping funnel, and add dry toluene solvent to the reactor at the same time, with a mass ratio of the reactant to the benzene water-carrying agent of 1:0.4; turn on the stirring, drop diethylenetriamine in an ice water bath, the dropping time is 2 hours, and the stirring reaction is 2 hours; change the oil bath, slowly heat up to 160°C and reflux for 6 hours to separate the water generated by the amidation reaction; then slowly heat up to 220°C and keep warm for 4 hours to separate the water generated by the imidazoline ring, and evaporate the solvent and unreacted raw materials, and then cool to about room temperature to obtain a five-finger polyimidazole intermediate.
[0060] Step 2: Synthesis of five-finger polyimidazoline quaternary ammonium salt
[0061] Under nitrogen protection, add the five-finger polyimidazoline intermediate to a four-necked flask equipped with a thermometer, a stirrer, a constant pressure dropping funnel, and a condenser, add the quaternary ammonium reagent hexadecane bromide to the constant pressure dropping funnel, and the molar ratio of the five-finger polyimidazoline intermediate to the quaternary ammonium reagent hexadecane bromide is 1:1; turn on the mechanical stirring, and at 70°C, drop the quaternary ammonium reagent hexadecane bromide into the reactor, and the dropping time is controlled at 0.5h; slowly raise the temperature to 140°C, The mixture was stirred and reacted for 4 hours. After the reaction was completed, the temperature was lowered to 30°C, and the quaternary ammonium reagent dimethyl carbonate was added to the constant pressure dropping funnel. The molar ratio of the five-finger-shaped polyimidazoline intermediate to the quaternary ammonium reagent dimethyl carbonate was 1:4. The mechanical stirring was turned on, and the quaternary ammonium reagent dimethyl carbonate was added dropwise to the reactor at 30°C. The dropping time was controlled within 1 hour. The temperature was slowly raised to 80°C, and the mixture was stirred and reacted for 8 hours. The solvent was evaporated under reduced pressure to obtain the five-finger-shaped polyimidazoline quaternary ammonium salt.
[0062] Step 3: The five-finger-shaped polyimidazoline quaternary ammonium salt corrosion inhibitor is a mixed formula product in which the mass proportion of the five-finger-shaped polyimidazoline quaternary ammonium salt is 30%, the mass proportion of OP-10 is 5%, the mass proportion of mercaptoethanol is 5%, the mass proportion of thiourea is 5%, the mass proportion of ethanol is 13%, and the rest is deionized water.
[0063] Comparative Example 1
[0064] The composition of the corrosion inhibitor of Comparative Example 1 is as follows: 30% by mass of benzyl chloride modified oleic acid diethylenetriamine imidazoline quaternary ammonium salt, 5% by mass of OP-10, 5% by mass of mercaptoethanol, 5% by mass of thiourea, 15% by mass of ethanol, and the rest is a mixed formula product of deionized water.
[0065] Performance Testing
[0066] Experimental agent: Five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor prepared in Examples 1-6, corrosion inhibitor in Comparative Example 1 Experimental medium: Simulated water quality of an oil field in the South China Sea (mineralization 5000 mg / L)
[0067] Experimental temperature: 80℃
[0068] H2S concentration: 20mg / L
[0069] Drug concentration: 40mg / L
[0070] Hanging material: X65 carbon steel
[0071] Evaluation standard: SY / T 5273 "Evaluation method for corrosion inhibitor performance of oilfield produced water"
[0072] Evaluation method:
[0073] Soak the steel test piece in anhydrous ethanol for about 5 minutes, take out the test piece, wipe it dry with filter paper, blow it dry with cold air, wrap it, put it in a desiccator to dry for 30 minutes, and weigh it (accurate to 0.0001g).
[0074] Pour 1.5L of water sample into the corrosion inhibitor high pressure evaluation kettle and add corrosion inhibitor with a concentration of 40mg / L. Fix three test pieces on the autoclave hanging system, install the autoclave, pass nitrogen and vacuum to remove oxygen in the kettle in turn, and inject carbon dioxide and nitrogen at the specified pressure of the experiment into the kettle. Control the temperature to 80℃, set the speed to 300rpm, and hang the dynamic piece for 72h. After heating at 80℃ for 72 hours, observe the water color and the appearance of the steel sheet, treat with standard pickling solution and anhydrous ethanol, and weigh, and finally calculate the corrosion rate and corrosion inhibition rate of the corrosion inhibitor.
[0075] Table 1 Performance evaluation of simulated water corrosion inhibitor in an oil field in the South China Sea
[0076] Experiment time: 72h / time Experiment type: Dynamic√Static□
[0077]
[0078]
[0079] The embodiments of this specific implementation method are all preferred embodiments of the present invention, and are not intended to limit the protection scope 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 protection scope of the present invention.
Claims
1. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor, characterized in that: The invention comprises the following components in mass percentage: 10-30% of five-finger-shaped polyimidazoline quaternary ammonium salt, 1-10% of OP-10, 1-10% of mercaptoethanol, 1-10% of thiourea, 10%-15% of alcohol solvent, and the balance is deionized water; The preparation method of the five-finger polyimidazoline quaternary ammonium salt comprises the following steps: synthesizing the five-finger polyimidazoline with organic acid and organic amine, and then modifying the five-finger polyimidazoline quaternary ammonium salt with quaternizing agents alkyl halide and dimethyl carbonate.
2. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 1, characterized in that: The synthetic method of the five-finger polyimidazoline is as follows: Under nitrogen protection, add a benzene water-carrying agent to diethylenetriaminepentaacetic acid, and under stirring, drop diethylenetriamine in an ice-water bath for 0.5 to 2 hours, and react by stirring for 1 to 2 hours; change to an oil bath, slowly heat up to 140°C to 160°C, and reflux for 1 to 6 hours to separate the water generated by the amidation reaction; then slowly heat up to 160°C to 220°C and keep warm for 1 to 4 hours to separate the water generated by the imidazoline ring formation, and evaporate the solvent and unreacted raw materials, and then cool to room temperature to obtain five-finger polyimidazole.
3. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 2, characterized in that: The molar ratio of diethylenetriaminepentaacetic acid to diethylenetriamine is 1:5-6.
4. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 2, characterized in that: The mass ratio of diethylenetriaminepentaacetic acid to benzene water-carrying agent is 1:0.1-0.
5.
5. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 2, characterized in that: The benzene type water-carrying agent may be toluene and / or xylene.
6. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 1, characterized in that: The synthesis method of five-finger polyimidazoline quaternary ammonium salt is as follows: Under nitrogen protection, stirring and 60°C to 80°C, a quaternary ammonium alkyl halide is added dropwise to the five-finger-shaped polyimidazoline, and the addition time is controlled within 0.5 to 1 h; the temperature is slowly raised to 120°C to 150°C, and the reaction is stirred for 2 to 6 h. After the reaction is completed, the temperature is lowered; and under stirring and 30°C to 50°C, a quaternary ammonium dimethyl carbonate is added dropwise, and the addition time is controlled within 0.5 to 1 h; the temperature is slowly raised to 70°C to 120°C, and the reaction is stirred for 4 to 8 h. The solvent is evaporated under reduced pressure to obtain a five-finger-shaped polyimidazoline quaternary ammonium salt.
7. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 6, characterized in that: The molar ratio of the five-finger polyimidazoline to the quaternary ammonium reagent alkyl halide is 1:1 to 3.
2.
8. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 6, characterized in that: The molar ratio of the five-finger polyimidazoline to the quaternizing agent dimethyl carbonate is 1:2-4.
2.
9. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 6, characterized in that: The quaternizing agent alkyl halides include hexadecane chloride, hexadecane bromide, octadecane chloride, and octadecane bromide.
10. A five-finger polyimidazoline quaternary ammonium salt corrosion inhibitor according to claim 1, characterized in that: The alcohol solvent is selected from one or more of methanol, ethanol and ethylene glycol.