An amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering

Abstract

The present application relates to oil and gas gathering and transferring system protection technical field, especially to a kind of oil and gas field gathering and transferring with amine doped graphene quantum dots corrosion inhibitor, including 30%~45% amine doped functionalized graphene quantum dots, 5%~15% dispersing agent and 40%~65% water.The present application a kind of oil and gas field gathering and transferring with amine doped graphene quantum dots corrosion inhibitor does not add solvent, synergist and other chemical reagent, only contains amine doped functionalized graphene quantum dots and dispersing agent, is friendly to environment, and after organic amine doped functionalization, N in corrosion inhibitor molecule can be combined with the strong force of metal surface, play the role of rivet, enhance the adsorption intensity of graphene on metal surface;Add dispersing agent can improve the uniformity and integrity of corrosion inhibitor film, there is synergistic effect between two, even without adding synergist can also realize efficient corrosion inhibition performance.

Description

Technical Field

[0001] This invention relates to the field of protection technology for oil and gas gathering and transportation systems, specifically to an amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation. Background Technology

[0002] CO2 is often present in oil and gas as a component of natural gas or associated gas, leading to significant carbon dioxide corrosion in oil and gas gathering and transportation systems. The high salinity of produced water further accelerates this corrosion. Corrosion products such as FeCO3 and sludge deposit as scale on the surfaces of pipes and equipment, causing under-deposit corrosion and resulting in severe localized corrosion and failure. This can also cause blockages, exacerbating problems such as wax deposition, asphalt formation, and blistering.

[0003] Adding corrosion inhibitors is one of the most common methods to suppress corrosion of produced water in oilfield gathering and transportation systems. Currently, the most commonly used corrosion inhibitors are mainly imidazoline derivatives and quinoline quaternary ammonium salts, often combined with thiourea and its derivatives to improve corrosion inhibition performance. Organic solvents and surfactants are also added to meet physicochemical performance requirements. However, the phosphorus, nitrogen, and sulfur components in commonly used corrosion inhibitors contribute to eutrophication of water bodies; surfactants are generally organochlorine compounds, which are toxic and harmful substances and environmentally unfriendly; organic solvents cause significant environmental pollution. Therefore, currently used corrosion inhibitors are all environmentally unfriendly chemical products. With the promulgation of new environmental protection laws, new environmentally friendly corrosion inhibitors are constantly being developed. Graphene quantum dots possess a variety of excellent properties; their good chemical inertness, barrier properties after planar spreading, and high hydrophobicity enable their application in the field of metal corrosion protection. Although graphene quantum dots can spread on metal surfaces to form a protective film and have a corrosion inhibition effect, the adsorption effect of ordinary graphene quantum dots is uneven and the adsorption strength is insufficient, resulting in an insignificant corrosion inhibition effect. Therefore, it is necessary to modify graphene quantum dots to improve their adsorption capacity. Summary of the Invention

[0004] To address the problems existing in the prior art, the present invention provides an amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation.

[0005] This invention is achieved through the following technical solution:

[0006] An amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation comprises 30%–45% amine-doped functionalized graphene quantum dots, 5%–15% dispersant and 40%–65% water.

[0007] Preferably, the dispersant is a DMF solution or a chloroform solution.

[0008] The preferred method for preparing amine-doped graphene quantum dots is as follows:

[0009] S1, Dissolve solid citric acid and organic amine in distilled water and stir to obtain the stock solution;

[0010] S2, dry the original solution to obtain the reaction product;

[0011] S3, wash the reaction product and centrifuge to obtain amine-doped functionalized graphene quantum dots.

[0012] Preferably, in S1, the molar ratio of the solid citric acid to the organic amine is 1:(2.5 to 3.5), the concentration of citric acid in the stock solution is 0.1 mmol / L to 5 mmol / L, and the concentration of the organic amine is 0.1 mmol / L to 15 mmol / L.

[0013] Preferably, in S1, the organic amine is urea, hexamethylenediamine, ethylenediamine, or ethanolamine.

[0014] Preferably, in S2, the drying temperature is 60℃~200℃.

[0015] Preferably, in step S2, the heat preservation time during drying is 4 to 5 hours.

[0016] Preferably, in step S3, ethanol or DMF solution is used for cleaning.

[0017] Preferably, in S3, the centrifugation rate is 5000 rpm to 8000 rpm.

[0018] Preferably, in S3, the centrifugation time is 5 min to 10 min.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] This invention discloses an amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation. It contains no solvents, synergists, or other chemical agents, only amine-doped functionalized graphene quantum dots and a dispersant. It is environmentally friendly. The large π-bond electrons in the graphene quantum dots within the corrosion inhibitor molecules can form coordinate bonds with metallic iron, resulting in chemical adsorption. The two-dimensional structure of graphene spreads across the metal surface, acting as a corrosion-inhibiting adsorption film, isolating corrosive media such as water, CO2, and Cl-. After functionalization with organic amine doping, the nitrogen in the corrosion inhibitor molecules can strongly bind to the metal surface, acting as a rivet and enhancing the adsorption strength of graphene on the metal surface. The addition of a dispersant improves the uniformity and integrity of the corrosion inhibitor film; the two have a synergistic effect, achieving high-efficiency corrosion inhibition even without the addition of a synergist.

[0021] The corrosion inhibitor in this invention is a novel environmentally friendly corrosion inhibitor that inhibits the corrosion of produced water in oil and gas field gathering and transportation systems. It has the characteristics of good corrosion inhibition effect, solvent-free, environmentally friendly, good water solubility, and low dosage. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the reaction route of the present invention. Detailed Implementation

[0023] The present invention will be further described in detail below with reference to specific embodiments. These descriptions are for explanation purposes only and are not intended to limit the scope of the invention.

[0024] This invention discloses an amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation, comprising 30% to 45% amine-doped functionalized graphene quantum dots, 5% to 15% dispersant and 40% to 65% water.

[0025] The dispersant is a DMF solution or a chloroform solution.

[0026] The preparation method of amine-doped graphene quantum dots is as follows:

[0027] S1, dissolve solid citric acid and organic amine in distilled water at a molar ratio of 1:(2.5-3.5) and stir to obtain the stock solution; wherein the organic amine is urea, hexamethylenetetramine, ethylenediamine or ethanolamine, and the concentration of citric acid in the stock solution is 0.1 mmol / L to 5 mmol / L, and the concentration of organic amine is 0.1 mmol / L to 15 mmol / L.

[0028] S2 is kept at 60-200℃ for 4-5 hours, and the original solution is dried to obtain the reaction product.

[0029] S3. The reaction product is washed with ethanol and then centrifuged at a speed of 5000 rpm to 8000 rpm for 5 min to 10 min. The supernatant ethanol is removed to obtain amine-doped functionalized graphene quantum dots.

[0030] The method for determining the corrosion rate of corrosion inhibitors is as follows:

[0031] Medium composition: NaCl: 100g / L, CO2 partial pressure 0.5MPa, total pressure 8MPa;

[0032] Test temperature: 40℃;

[0033] Test duration: 96 hours;

[0034] Test material: L360 steel.

[0035] First, the L360 steel was polished to a bright finish, then cleaned with petroleum ether, acetone, and ethanol, dried, and weighed. A prepared, deoxygenated solution was placed in a high-temperature, high-pressure reactor equipped with a rotating device, along with 200 ppm of a prepared corrosion inhibitor. The mixture was stirred thoroughly. The weighed L360 steel was then suspended in the high-temperature, high-pressure reactor. The temperature was raised to 40°C, and 0.5 MPa of CO2 was added. The pressure was increased to 8 MPa using high-purity N2, with the flow rate adjusted to 1 m / s. After stabilizing under these conditions for 96 hours, the sample was removed, the corrosion product film on the sample surface was removed, and the sample was dried, weighed, and the corrosion rate was calculated.

[0036] Example 1

[0037] Amine-doped functionalized graphene quantum dots were prepared by the following process: Citric acid and urea were dissolved in 500 mL of distilled water at a molar ratio of 1:3 and mechanically stirred until a clear and transparent solution was obtained; the solution was transferred to a reaction vessel and placed in an oven, heated to 180 °C and kept at that temperature for 4.5 h; the reaction product was washed with 450 mL of ethanol and centrifuged at 5000 rpm for 5 min to obtain urea-doped functionalized graphene quantum dots.

[0038] The corrosion inhibitor consists of the following components by weight percentage: 45% urea-doped functionalized graphene quantum dots, 15% chloroform, and 40% water. The corrosion inhibitor prepared by this method exhibits good solubility in the test medium, with a corrosion rate of 0.071 mm / a in the test medium.

[0039] Example 2

[0040] Amine-doped functionalized graphene quantum dots were prepared by the following process: Citric acid and hexamethylenetetramine were dissolved in 500 mL of distilled water at a molar ratio of 1:3.5 and mechanically stirred until a clear and transparent solution was obtained; the solution was transferred to a reaction vessel and placed in an oven, heated to 200 °C and kept at that temperature for 5 h; the reaction product was washed with 500 mL of ethanol and centrifuged at 5000 rpm for 5 min to obtain hexamethylenetetramine-doped functionalized graphene quantum dots.

[0041] The corrosion inhibitor consists of the following components by weight percentage: 40% hexamethylenetetramine-doped functionalized graphene quantum dots, 10% DMF, and 50% water. The corrosion inhibitor prepared by this method exhibits good solubility in the test medium, with a corrosion rate of 0.082 mm / a in the test medium.

[0042] Example 3

[0043] Amine-doped functionalized graphene quantum dots were prepared by the following process: Citric acid and ethylenediamine were dissolved in 500 mL of distilled water at a molar ratio of 1:2.5 and mechanically stirred until a clear and transparent solution was obtained; the solution was transferred to a reaction vessel and placed in an oven, heated to 170 °C and kept at that temperature for 4 h; the reaction product was washed with 400 mL of ethanol and centrifuged at 5000 rpm for 8 min to obtain ethylenediamine-doped functionalized graphene quantum dots.

[0044] The corrosion inhibitor consists of the following components by weight percentage: 35% ethylenediamine-doped functionalized graphene quantum dots, 5% chloroform, and 60% water. The corrosion inhibitor prepared by this method exhibits good solubility in the test medium, with a corrosion rate of 0.078 mm / a in the test medium.

[0045] Example 4

[0046] Amine-doped functionalized graphene quantum dots were prepared by the following process: Citric acid and ethanolamine were dissolved in 500 mL of distilled water at a molar ratio of 1:3 and mechanically stirred until a clear and transparent solution was obtained; the solution was transferred to a reaction vessel and placed in an oven, heated to 160 °C and kept at that temperature for 4 h; the reaction product was washed with 300 mL of ethanol and centrifuged at 5000 rpm for 10 min to obtain ethanolamine-doped functionalized graphene quantum dots.

[0047] The corrosion inhibitor consists of the following components by weight percentage: 30% ethanolamine-doped functionalized graphene quantum dots, 5% DMF, and 65% water. The corrosion inhibitor prepared by this method exhibits good solubility in the test medium, with a corrosion rate of 0.081 mm / a in the test medium.

[0048] Comparative example:

[0049] The corrosion inhibitor is the urea-doped functionalized graphene quantum dot from Example 1, with an addition amount of 100 ppm. It has good water solubility in the test medium and a corrosion rate of 0.097 mm / a.

[0050] The above embodiments show that there is a good synergistic effect between amine-doped functionalized graphene quantum dot corrosion inhibitors and dispersants, and the combination of the two has a good inhibitory effect on the corrosion of oilfield produced water.

Claims

1. An amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation, characterized in that, The corrosion inhibitor comprises, by weight percentage, 30%–45% amine-doped functionalized graphene quantum dots, 5%–15% dispersant, and 40%–65% water; The dispersant is DMF or chloroform; The preparation method of amine-doped graphene quantum dots is as follows: S1, Dissolve solid citric acid and organic amine in distilled water and stir to obtain the stock solution; S2, dry the original solution to obtain the reaction product; S3, wash the reaction product and centrifuge to obtain amine-doped functionalized graphene quantum dots; In S1, the molar ratio of solid citric acid to organic amine is 1:(2.5~3.5), the concentration of citric acid in the stock solution is 0.1 mmol / L~5 mmol / L, and the concentration of organic amine is 0.1 mmol / L~15 mmol / L; In S1, the organic amine is urea, hexamethylenetetramine, ethylenediamine, or ethanolamine; The drying temperature during drying is 60℃~200℃; The heat preservation time during drying is 4 h to 5 h.

2. The amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation according to claim 1, characterized in that, In S3, cleaning is performed using ethanol or DMF solution.

3. The amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation according to claim 1, characterized in that, In S3, the centrifugation rate is 5000 rpm to 8000 rpm.

4. The amine-doped graphene quantum dot corrosion inhibitor for oil and gas field gathering and transportation according to claim 1, characterized in that, In S3, the centrifugation time is 5 min to 10 min.

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