Preparation method and application of carbon dot derivatives with corrosion inhibition and surface activity

Abstract

The present invention relates to the field of oil and gas extraction technology, and in particular to a method for preparing and applying a carbon dot derivative having corrosion inhibition and surface activity, comprising the following steps: A. pre-treating biological waste peels into a powder; B. dispersing the powder obtained in step A in deionized water, then adding a polyamine for reaction, cooling, filtering, dialyzing, and drying after the reaction to obtain nitrogen-doped carbon dots; C. preparing the nitrogen-doped carbon dots obtained in step B into a solution, adding a halogenated alkane for reaction, layering after the reaction to obtain a reaction product solution, and then distilling under reduced pressure to obtain a carbon dot derivative. The carbon dot derivative prepared by the present invention has both corrosion inhibition and surface activity, and has good corrosion inhibition performance for salt solutions, hydrochloric acid, hydrofluoric acid, and mixed acid solutions at high temperatures, with a corrosion inhibition efficiency of up to 95.52%; and can reduce the surface tension and interfacial tension of oil and water, with the interfacial tension as low as 0.042 mN / m and the surface tension as low as 26.59 mN / m, and a temperature resistance of up to 120°C.

Description

Technical Field

[0001] The present invention relates to the technical field of oil and gas extraction, and in particular to a preparation method and application of a carbon dot derivative with corrosion inhibition and surface activity. Background Art

[0002] During oil and gas production operations, brine, hydrochloric acid, etc. are often used as operating fluids. These operating fluids need to be injected into the formation through a tubing string. Oil and gas reservoirs are often accompanied by high temperatures. Under high temperature conditions, the corrosion of the tubing string by brine and acid often affects the service life of the tubing string. Severe corrosion can also cause corrosion and perforation of the casing string, posing a huge safety hazard to oil and gas production operations, and even causing the scrapping of oil and gas wells, resulting in huge economic losses. This requires adding corrosion inhibitors to the brine and acid to delay the corrosion of the tubing string. After the oil and gas production operating fluid is injected into the formation, in order to achieve the functional properties of the fluid, it is often necessary to add surfactants to the brine and acid to reduce the surface tension. In particular, in the tertiary oil recovery process, the interfacial tension often needs to be reduced to below 0.01mN / m. In order to achieve these functional properties, the traditional practice is generally to use a combination of multiple surfactants.

[0003] As an emerging nanomaterial, carbon quantum dots (CQDs) have garnered widespread attention in various research fields due to their biocompatibility, water solubility, and simple synthesis methods. For example, the use of CQDs as corrosion inhibitors has been reported in patents and literature, but most studies have focused on room temperature applications, with limited research specifically targeting oilfield production processes. Summary of the Invention

[0004] In order to solve the above technical problems, embodiments of the present invention provide a preparation method and application of carbon dot derivatives with corrosion inhibition and surface activity.

[0005] To achieve the above objectives, the embodiments of the present invention adopt the following technical solutions:

[0006] In one aspect, the present invention provides a method for preparing a carbon dot derivative having corrosion inhibition and surface activity, comprising the following steps:

[0007] A. Pre-treating biological waste peels into powder;

[0008] B. Dispersing the powder obtained in step A in deionized water, then adding polyamine to react, cooling, filtering, dialyzing and drying to obtain nitrogen-doped carbon dots;

[0009] C. The nitrogen-doped carbon dots obtained in step B are prepared into a solution, and a halogenated alkane is added to react. After the reaction, the reaction product solution is obtained by layering, and then the solution is distilled under reduced pressure to obtain a carbon dot derivative.

[0010] The carbon dot derivatives provided by the present invention are derived from biological waste, which has the characteristics of wide sources and low cost. On the other hand, after the carbon dots are nitrogen-doped with polyamines, the exposed amino groups on the carbon dots react with halogenated alkanes to obtain a carbon dot derivative with one end being a carbon dot and the other end being a hydrophobic group. This carbon dot derivative, based on the strong adsorption effect of the carbon dots, realizes hydrophobicity and surface activity, which can isolate the further corrosion of salt and acid on steel. The amphiphilic structure also makes it unnecessary to add other surfactants to assist in reducing the surface tension, laying the foundation for its application in multiple fields of oil and gas production. The carbon dot derivatives prepared by the present invention have both corrosion inhibition and surface activity. At high temperature, they have good corrosion inhibition performance for salt solution, hydrochloric acid, hydrofluoric acid and mixed acid solution, with the corrosion inhibition efficiency reaching up to 95.52%. They can also reduce the surface tension and interfacial tension of oil and water, with the interfacial tension as low as 0.042mN / m and the surface tension as low as 26.59mN / m, and the temperature resistance reaches 120°C.

[0011] In some embodiments, in step A, the pretreatment specifically includes the following steps:

[0012] The biological waste peel is rinsed with clean water, dried in a vacuum drying oven at 60-70° C. for 12-18 hours, crushed with a grinder, and sieved through a 100-mesh screen to obtain a powder.

[0013] In some embodiments, in step A, the bio-waste fruit peels include at least one of grapefruit peels, orange peels, banana peels, and lemon peels.

[0014] In some embodiments, in step B, the mass ratio of the powder to the polyamine is (0.3-0.8): (0.6-3).

[0015] In some embodiments, in step B, the polyamine includes at least one of hexamethylenediamine, cyclohexamethylenediamine, diethylenetriamine, aminopyridine, and piperazine.

[0016] In some embodiments, in step B, the reaction temperature is 150-240° C., and the reaction time is 3-24 h.

[0017] In some embodiments, in step B, the filtration is performed using a 0.22 μm filter membrane, the dialysis is performed using an 800-1500 Da dialysis bag, the water is changed every 4 hours, and the dialysis is performed for 20-30 hours before vacuum drying.

[0018] In some embodiments, in step C, the mass ratio of the halogenated alkane to the polyamine in step B is (0.5-2.5): (0.6-3).

[0019] In some embodiments, in step C, the halogenated alkane has a general formula of RX, wherein R is any one of isooctyl, decane, tetradecyl and octadecyl, X is Cl or Br, the reaction temperature is 70-100° C., and the reaction time is 3-12 h.

[0020] On the other hand, the present invention also provides a use of the carbon dot derivatives prepared by the above preparation method in oil and gas production operations.

[0021] The present invention also provides an application of a carbon dot derivative with corrosion inhibition and surface activity. The present invention provides three typical applications in oil and gas production, but is not limited to these applications. The carbon dot derivative of the present invention can be used in any application involving corrosion inhibition and / or surface activity.

[0022] Specifically, the first application provided by the present invention is in a brine solution, which can be a completion fluid, workover fluid, fracturing fluid, or tertiary oil recovery fluid for oil and gas production, specifically in sodium chloride or potassium chloride solutions or mixed solutions of different concentrations.

[0023] The second application provided by the present invention is in acidic liquid, which can be acidizing liquid, acidic completion fluid, acidic well washing fluid, etc. in oil and gas production, specifically hydrochloric acid of different concentrations or a mixture of hydrochloric acid and hydrofluoric acid.

[0024] The third application provided by the present invention is in a composite solution of brine and acid. The composite solution can be an acidizing fluid, acid completion fluid, acid well washing fluid, etc. for oil and gas production. Specifically, it is a mixture of sodium chloride and potassium chloride solutions with different concentrations of hydrochloric acid or a mixture of hydrochloric acid and hydrofluoric acid added thereto. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 TEM image of carbon dots prepared in Example 3 of the present invention;

[0026] Figure 2 This is the fluorescence spectrum of carbon dots prepared in Example 3 of the present invention. DETAILED DESCRIPTION

[0027] The following will be combined with the accompanying drawings to clearly and completely describe the technical solutions in some embodiments of the present disclosure. Obviously, the embodiments described are only some embodiments of the present disclosure, not all embodiments. Based on the embodiments provided by the present disclosure, all other embodiments obtained by ordinary technicians in this field are within the scope of protection of the present disclosure.

[0028] Example 1

[0029] (1) Rinse the grapefruit peel with clean water, dry it in a vacuum drying oven at 60°C for 18 h, take it out and crush it with a grinder, and sieve it with a 100-mesh sieve to collect the fine powder for later use.

[0030] (2) Take 0.3 g of grapefruit peel powder passed through a 100-mesh sieve and disperse it in 20 mL of deionized water. Under ultrasonic stirring, the dispersion is placed in a tetrafluoroethylene reactor and stirring is started for 20 min.

[0031] (3) Under continuous stirring, 0.6 g of hexamethylenediamine was added dropwise to a tetrafluoroethylene reactor, the temperature was raised to 150° C., the reaction was continued for 3 h, and the mixture was cooled to obtain a nitrogen-doped mixed solution.

[0032] (4) The obtained nitrogen-doped mixed solution was filtered through a 0.22 μm filter membrane to obtain a clear liquid.

[0033] (5) The obtained clarified liquid was placed in a 1500Da dialysis bag for dialysis, and the water was changed every 4 hours. After dialysis for 30 hours, the liquid was vacuum dried to obtain nitrogen-doped carbon dots.

[0034] (6) Add 20 mL of 95% ethanol to the three-necked flask and start stirring. Add the nitrogen-doped carbon dots obtained in the above step to the three-necked flask and continue stirring for 30 minutes to dissolve them.

[0035] (7) 2.5 g of chloroisooctane was added to the three-necked flask, the temperature was raised to 100° C., the mixture was reacted for 12 h, and then cooled to room temperature to obtain a reaction mixture.

[0036] (8) The reaction mixture was poured into a separatory funnel, 10 mL of distilled water was added, and the mixture was allowed to stand for stratification after being shaken thoroughly. The lower layer was the reaction product solution.

[0037] (9) The reaction product solution is distilled under reduced pressure to remove the solvent, thereby obtaining a carbon dot derivative.

[0038] Example 2

[0039] The present invention provides a method for preparing a carbon dot derivative having corrosion inhibition and surface activity, comprising the following steps:

[0040] (1) Rinse the orange peel with clean water, dry it in a vacuum drying oven at 70°C for 12 hours, take it out and crush it with a grinder, and sieve it with a 100-mesh sieve to collect the fine powder for later use.

[0041] (2) Take 0.8 g of orange peel powder passed through a 100-mesh sieve and disperse it in 20 mL of deionized water. Under ultrasonic stirring, the dispersion is placed in a tetrafluoroethylene reactor and stirring is started for 20 min.

[0042] (3) Under continuous stirring, 3.0 g of piperazine was added dropwise to a tetrafluoroethylene reactor, the temperature was raised to 240° C., and the reaction was continued for 24 h. The mixture was then cooled to obtain a nitrogen-doped mixed solution.

[0043] (4) The obtained nitrogen-doped mixed solution was filtered through a 0.22 μm filter membrane to obtain a clear liquid.

[0044] (5) The obtained clarified liquid was placed in an 800Da dialysis bag for dialysis, and the water was changed every 4 hours. After dialysis for 20 hours, the liquid was vacuum dried to obtain nitrogen-doped carbon dots.

[0045] (6) Add 20 mL of 95% ethanol to the three-necked flask and start stirring. Add the nitrogen-doped carbon dots obtained in the above step to the three-necked flask and continue stirring for 20 minutes to dissolve them.

[0046] (7) 0.5 g of bromotetradecane was added to the three-necked flask, the temperature was raised to 70° C., the reaction was continued for 3 h, and the mixture was cooled to room temperature to obtain a reaction mixture.

[0047] (8) The reaction mixture was poured into a separatory funnel, and 20 mL of distilled water was added. After vibrating thoroughly, the mixture was allowed to stand and separate into layers. The lower layer was the reaction product solution.

[0048] (9) The reaction product solution is distilled under reduced pressure to remove the solvent, thereby obtaining a carbon dot derivative.

[0049] Example 3

[0050] The present invention provides a method for preparing a carbon dot derivative having corrosion inhibition and surface activity, comprising the following steps:

[0051] (1) Rinse the lemon peel with clean water, dry it in a vacuum drying oven at 65°C for 16 hours, take it out and crush it with a grinder, and sieve it with a 100-mesh sieve to collect the fine powder for later use.

[0052] (2) Take 0.5 g of lemon peel powder passed through a 100-mesh sieve and disperse it in 20 mL of deionized water. Under ultrasonic stirring, the dispersion is placed in a tetrafluoroethylene reactor and stirring is started for 20 min.

[0053] (3) Under continuous stirring, 1.8 g of polyamine was added dropwise to a tetrafluoroethylene reactor. The polyamines were cyclohexanediamine and diethylenetriamine in a mass ratio of 3:7. The temperature was raised to 195° C., and the reaction was continued for 13.5 h. The mixture was then cooled to obtain a nitrogen-doped mixed solution.

[0054] (4) The obtained nitrogen-doped mixed solution was filtered through a 0.22 μm filter membrane to obtain a clear liquid.

[0055] (5) The obtained clarified liquid was placed in a 1000Da dialysis bag for dialysis, and the water was changed every 4 hours. After dialysis for 25 hours, the liquid was vacuum dried to obtain nitrogen-doped carbon dots.

[0056] (6) Add 20 mL of 95% ethanol to a three-necked flask and start stirring. Add the nitrogen-doped carbon dots obtained in the above step to the three-necked flask and continue stirring for 25 minutes to dissolve them.

[0057] (7) 1.5 g of octadecane chloride was added to the three-necked flask, the temperature was raised to 85° C., the reaction was continued for 7.5 h, and the mixture was cooled to room temperature to obtain a reaction mixture.

[0058] (8) The reaction mixture was poured into a separatory funnel, and 15 mL of distilled water was added. After vibrating thoroughly, the mixture was allowed to stand and separate into layers. The lower layer was the reaction product solution.

[0059] (9) The reaction product solution is distilled under reduced pressure to remove the solvent, thereby obtaining a carbon dot derivative.

[0060] Comparative Example 1

[0061] The implementation steps in Example 1 were carried out to step (5), ie, the reaction was terminated to obtain nitrogen-doped carbon dots without subsequent quaternization reaction.

[0062] Comparative Example 2

[0063] The implementation steps in Example 1 were carried out to step (5), ie, the reaction was terminated to obtain nitrogen-doped carbon dots without subsequent quaternization reaction. 30% hexadecyltrimethylammonium bromide was added during the corrosion inhibition performance and surface-interfacial tension evaluation.

[0064] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the performance evaluation of the carbon dot derivatives and their applications obtained in Examples 1-3 and Comparative Examples 1-2 was conducted.

[0065] Firstly, the prepared carbon dots were characterized.

[0066] from Figure 1 From cryo-TEM, we can see that the particle size of most carbon dots is evenly distributed between 2-5 nm and they are evenly dispersed.

[0067] from Figure 2 From the fluorescence spectrum, we can see that under different excitation wavelengths of 280nm-460nm, the fluorescence intensity of carbon dots first decreases and then increases, and the peak position and intensity of the carbon dot emission spectrum are strongly dependent on the excitation wavelength. This phenomenon is mainly due to the defects on the carbon dot surface acting as excitation energy sinks and the different selectivity of particle size to light. This phenomenon is a typical characteristic of graphite carbon dots.

[0068] Secondly, the performance of the carbon point derivatives prepared in Examples 1-3 and Comparative Examples 1-2 was evaluated in three different application scenarios. The corrosion inhibition performance was tested using the industry-standard weight loss method. The interfacial tension was tested using a rotating drop contact angle tester, and the surface tension was tested using a surface tension meter. Experimental conditions for corrosion inhibition rate: The N80 steel sheet was immersed in a 5% sodium chloride aqueous solution and allowed to stand at 120°C for 24 hours, and the weight loss method was used to test the corrosion rate before and after the steel sheet was corroded; the N80 steel sheet was immersed in 8% hydrochloric acid and 2% hydrofluoric acid and allowed to stand at 80°C for 24 hours, and the weight loss method was used to test the corrosion rate before and after the steel sheet was corroded; the N80 steel sheet was immersed in 10% sodium chloride and 5% hydrochloric acid and allowed to stand at 100°C for 24 hours, and the weight loss method was used to test the corrosion rate before and after the steel sheet was corroded; the surface interfacial tension is the interfacial tension with kerosene tested at 25°C after the solution has been at rest for 24 hours at 100°C, and the surface tension with air tested at 25°C. The specific test results are shown in Table 1 below:

[0069] Table 1 Corrosion inhibition performance and surface activity of carbon dot derivatives

[0070]

[0071]

[0072] Experimental results demonstrate that the three examples of the carbon dot derivatives provided by this invention exhibit excellent corrosion inhibition performance in their respective application environments, along with excellent surface activity, capable of reducing interfacial and surface tensions, even at low addition concentrations. However, the performance of the two comparative examples is significantly inferior to that of the examples, demonstrating that nitrogen-doped carbon dots alone, or in combination with surfactants, cannot achieve adequate corrosion inhibition efficiency and surface activity under high temperature conditions.

[0073] In the description of this specification, specific features, structures, materials or characteristics may be combined in an appropriate manner in any one or more embodiments or examples.

[0074] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any modifications or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be based on the scope of protection of the claims.

Claims

1. A method for preparing a carbon dot derivative having corrosion inhibition and surface activity, characterized in that: The following steps are involved: A. pre-treating biological waste peels into powder, wherein the biological waste peels include at least one of grapefruit peels, orange peels, banana peels, and lemon peels; B. dispersing the powder obtained in step A in deionized water, then adding a polyamine for reaction, cooling, filtering, dialyzing, and drying to obtain nitrogen-doped carbon dots, wherein the polyamine comprises at least one of hexamethylenediamine, cyclohexamethylenediamine, diethylenetriamine, aminopyridine, and piperazine; C. The nitrogen-doped carbon dots obtained in step B are prepared into a solution, a halogenated alkane is added for reaction, and after the reaction, the reaction product solution is obtained by layering, and then the solution is distilled under reduced pressure to obtain a carbon dot derivative. The halogenated alkane has the general formula RX, wherein R is any one of isooctyl, decane, tetradecyl, and octadecyl, and X is Cl or Br. The reaction temperature is 70-100° C., and the reaction time is 3-12 h.

2. The preparation method according to claim 1, characterized in that In step A, the pretreatment specifically includes the following steps: The biological waste peel is rinsed with clean water, dried in a vacuum drying oven at 60-70° C. for 12-18 hours, crushed with a grinder, and sieved through a 100-mesh screen to obtain a powder.

3. The preparation method according to claim 1, characterized in that In step B, the mass ratio of the powder to the polyamine is (0.3-0.8): (0.6-3).

4. The preparation method according to claim 1, characterized in that In step B, the reaction temperature is 150-240° C., and the reaction time is 3-24 h.

5. The preparation method according to claim 1, characterized in that In step B, the filtration is performed using a 0.22 µm filter membrane, the dialysis is performed using an 800-1500 Da dialysis bag, the water is changed every 4 hours, and the dialysis is performed for 20-30 hours followed by vacuum drying.

6. The preparation method according to claim 1, characterized in that In step C, the mass ratio of the halogenated alkane to the polyamine in step B is (0.5-2.5): (0.6-3).

7. Use of a carbon dot derivative prepared by the preparation method according to any one of claims 1 to 6 in oil and gas production operations.

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