A high-temperature resistant composite nanofluid scale inhibitor and its preparation method

Abstract

The present invention discloses a high-temperature resistant composite nanofluid scale inhibitor and a preparation method thereof, belonging to the technical field of oilfield chemistry; the composite nanofluid scale inhibitor is prepared from modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS, surfactant, inorganic salt and deionized water; the calcium-based nano modifier calcium-based poly-sulfonic acid contains a large number of sulfonic acid, carboxylic acid and hydroxyl groups, has strong hydrophilicity, calcium ion tolerance and calcium ion chelation property, and has a good scale inhibition effect on calcium carbonate scale and barium sulfate scale; at the same time, the modified graphene oxide nano has large-scale conjugated rings, a large number of carboxylic acid and hydroxyl groups, and synergistically enhances the effect with calcium-based poly-sulfonic acid under the action of anion shielding and steric hindrance effect, further improving the high-temperature resistance and scale inhibition performance of the nano scale inhibitor, having a good scale inhibition effect, effectively solving the problem of scale formation in oilfield water injection and fracturing flowback, and having a good promotion prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of oilfield exploitation, and particularly relates to a high-temperature resistant composite nanofluid scale inhibitor and a preparation method thereof. Background Art

[0002] In the development of unconventional tight / shale oil and gas reservoirs, water-based fracturing fluids are used for fracturing transformation. The fracturing scale of "thousands of cubic meters of sand and tens of thousands of cubic meters of fluid" is large, and a large amount of fracturing fluid is injected into the formation, resulting in two problems: First, the water-based fracturing fluid injected into the formation dissolves the soluble salt ore in the reservoir, resulting in a high salinity of the produced fluid; Second, during the high-temperature gel-breaking process of the fracturing fluid system in the reservoir, a water-rock reaction occurs with the rock, dissolving a large amount of metal ions (sodium, potassium, calcium, magnesium, etc.). Especially for special strata rich in alkali salt ore, the produced fluid and formation water are rich in bicarbonate ions. Under the combined action of the above factors, it is extremely vulnerable to the influence of temperature, pressure, salinity, and ion composition in the formation or wellbore, resulting in scale formation in the formation or wellbore, greatly reducing the seepage capacity in the pores of the oil and gas formation and the flow capacity in the wellbore, especially seriously affecting well testing and later production. In recent years, the scale inhibitors used in water treatment and oilfield produced water have developed from the initial phosphate scale inhibitors that are prone to cause water pollution to green scale inhibitors such as homopolymer high-temperature resistant scale inhibitors and copolymer high-temperature resistant scale inhibitors. However, there is no effective salt scale inhibitor for calcium carbonate scale formation or crystallization in the reservoir or wellbore under high-temperature, high salinity, and sodium bicarbonate water type conditions.

[0003] Through retrieval, the following several patent disclosure documents related to this invention patent application were found; for example, a high-temperature resistant composite scale and corrosion inhibitor and its preparation method CN114716031A synthesized a Mannich base salt and sodium polyaspartate, and formed a composite scale inhibitor by compounding the two, which has the properties of being green, high-temperature resistant, highly efficient in scale inhibition and corrosion inhibition, but the preparation process of sodium polyaspartate is relatively complex and the reaction temperature is high (>200°C). A high-temperature resistant scale inhibitor and its preparation method CN114920367B copolymerized a polymer scale inhibitor from carboxymethyl β-cyclodextrin, 2-acrylamide-2-methylpropanesulfonic acid monomer and sodium p-styrenesulfonate, which has high-temperature resistance and relatively high scale inhibition efficiency, but its scale inhibition performance is limited under the conditions of high calcium ions and carbonate or bicarbonate. A neutral high-temperature resistant salt inhibition and scale inhibitor and its preparation method CN117776418B is composed of an alcohol carboxylic acid quaternary copolymer, polyepoxysuccinic acid, nitrilotriacetic acid, polyethylene glycol, a pH regulator and water, and has good scale inhibition effect under neutral and high-temperature (120°C) conditions, but the scale inhibition effect on calcium carbonate scale is not ideal under alkaline high-temperature conditions. A thermally associating scale inhibitor, an alkaline scale-inhibiting polymer fracturing fluid system and its preparation method CN117362658A synthesized a temperature-sensitive oligomer containing terminal amino groups from N,N-dimethylacrylamide and diacetone acrylamide, and obtained a copolymer from maleic anhydride, 2-acrylamide-2-methylpropanesulfonic acid, and allyl polyoxyethylene acrylsulfonate sodium, and then prepared a thermally associating scale inhibitor by grafting the oligomer and the copolymer. This scale inhibitor has good compatibility with the fracturing fluid, high scale inhibition efficiency, and strong resistance to calcium ions and bicarbonate ions, but has a high dosage (0.1 - 0.3%) and relatively insufficient high-temperature resistance and long-term effectiveness. Summary of the Invention

[0004] The object of the present invention is to overcome the shortcomings of the prior art and provide a high-temperature resistant composite nanofluid scale inhibitor and its preparation method, which can effectively inhibit the occurrence of calcium carbonate scaling and still have good scale inhibition effect under high temperature, high salt and alkaline (pH = 7 - 9) conditions; this composite nanofluid scale inhibitor is prepared from modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, surfactant, inorganic salt and deionized water; the calcium-based nano modifier calcium-based polysulfonic acid contains a large number of sulfonic acid, carboxylic acid and hydroxyl groups, has strong hydrophilicity, calcium ion tolerance and calcium ion chelating property, and has good scale inhibition effect on calcium carbonate scale and barium sulfate scale; at the same time, the modified graphene oxide nano has large-scale conjugated rings, a large number of carboxylic acid and hydroxyl groups, and synergistically enhances the effect with calcium-based polysulfonic acid under the action of anion shielding and large steric hindrance effect, further improving the high-temperature resistance and scale inhibition performance of the nano scale inhibitor, having good scale inhibition effect, effectively solving the problems of scale formation in oilfield water injection and fracturing flowback, and having good promotion prospects.

[0005] To achieve the above technical effects, the following technical solutions are adopted:

[0006] A high-temperature resistant composite nanofluid scale inhibitor, comprising:

[0007] Modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, surfactant, inorganic salt and deionized water;

[0008] The mass concentration of the modified graphene oxide nano AP-GO in the scale inhibitor is 0.01 - 0.1%;

[0009] The mass concentration of the surfactant in the scale inhibitor is 0.1 - 0.4%;

[0010] The mass concentration of the inorganic salt in the scale inhibitor is 0.3 - 0.5%;

[0011] The mass ratio of the modified graphene oxide nano AP-GO to the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS is 1:4 - 1:6;

[0012] The inorganic salt is one or more of potassium chloride and sodium chloride;

[0013] The surfactant is one or more of sodium dodecylbenzenesulfonate, sodium hexadecyl sulfate, sodium hexadecyl sulfonate, sodium lauryl polyoxyethylene ether sulfate and disodium lauryl sulfosuccinate.

[0014] Further, the structural formula of the modified graphene oxide nano AP-GO is:

[0015] .

[0016] Further, the water is deionized water; the surfactant is sodium hexadecyl sulfonate and disodium lauryl sulfosuccinate.

[0017] Further, the specific preparation method of the modified graphene oxide nano AP-GO is:

[0018] Take 0.5 - 1.0 g of graphene oxide GO in 100 - 200 g of deionized water and ultrasonically disperse for 1 - 2 h to form a GO dispersion; under stirring conditions, add 3-amino-1,2-propanediol AP to the GO dispersion at a rate of 5 - 10 mL / min, and continue to react at 50 - 80 °C for 4 - 6 h; add 0.5 - 2 g of sodium chloride to the reaction mixture and stir to disperse, then centrifuge at 1000 - 2000 r / min for 10 - 20 min, discard the upper clear liquid, wash the lower solid, and repeat 2 - 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano AP-GO; the reaction formula of the preparation method is as follows:

[0019] 。

[0020] Furthermore, the mass ratio of the graphene oxide GO to 3-amino-1,2-propanediol AP is 1:1 to 1:4.

[0021] Furthermore, the lower-layer solid is washed with a mixed solution of ethanol and deionized water with a volume ratio of 1:1.

[0022] Furthermore, the specific preparation method of the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS is as follows:

[0023] Take calcium chloride and dissolve it in water to form a calcium chloride solution, and the mass concentration of the calcium chloride solution is 0.1% to 1%;

[0024] Take poly(2-acrylamido-2-methylpropanesulfonic acid) PAMPS and dissolve it in water to form a PAMPS solution, and the mass concentration of the PAMPS solution is 0.5% to 1.5%;

[0025] Stir the calcium chloride solution continuously, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 5 to 10 mL / min to produce a white suspension, and continuously stir for 15 to 30 min; centrifuge the above suspension at 1000 to 3000 r / min for 5 to 20 min, discard the upper-layer clear liquid, and wash the solid with water 2 to 3 times; dry the washed white solid at 50 - 80 °C to make a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS.

[0026] Furthermore, the mass ratio of the calcium chloride to poly(2-acrylamido-2-methylpropanesulfonic acid) PAMPS is 1:1 to 1:3.

[0027] Furthermore, the specific preparation method of the high-temperature resistant composite nanofluid scale inhibitor is as follows:

[0028] Mix the modified graphene oxide nano AP-GO and the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS with inorganic salts, surfactants and water according to the described concentrations and mass ratios, and then heat and ultrasonically disperse them at 40 - 60 °C for 10 - 30 min to obtain the high-temperature resistant composite nanofluid scale inhibitor.

[0029] Beneficial effects:

[0030] The beneficial effects of the present invention are as follows:

[0031] (1) The present invention provides a high-temperature resistant composite nanofluid scale inhibitor, which is composed of anion-modified graphene oxide and calcium-based polysulfonic acid. The calcium-based polysulfonic acid contains a large number of sulfonic acid, carboxylic acid and hydroxyl groups, has strong hydrophilicity, calcium ion tolerance and calcium ion chelating property, and has good scale inhibition effect on calcium carbonate scale and barium sulfate scale. In addition, the modified graphene oxide in the present invention has large-scale conjugated rings, a large number of carboxylic acid and hydroxyl groups, and synergistically enhances the effect with calcium-based polysulfonic acid under the action of anion shielding and steric hindrance effect. The synergistic effect of modified graphene oxide nanoparticles, calcium-based polysulfonic acid, surfactant and inorganic salt is used to further improve the high-temperature resistance and scale inhibition performance of the nanofluid scale inhibitor.

[0032] (2) The preparation process of the high-temperature resistant composite nanofluid scale inhibitor provided by the present invention is relatively simple, the reaction conditions are mild, it is phosphorus-free, green and environmentally friendly, has good dispersibility, the particle size is <500 nm, and has strong environmental adaptability. Especially, it has high-efficiency scale inhibition under the conditions of high temperature, high salinity, high concentration of carbonate or bicarbonate (>10000 mg / L) and high calcium ion water quality, and has a good effect on solving the scale formation problems in oilfield water injection and fracturing flowback, and has good promotion prospects. Brief Description of the Drawings

[0033] Figure 1 It is the infrared spectrum of the modified graphene oxide nanoparticle AP-GO in the embodiment of the present invention. Detailed Embodiments

[0034] In order to make the purpose, technical solutions and advantages of the present invention clearer, the following embodiments are used to further describe the present invention in detail. It should be understood that the specific embodiments described here are only used to explain the present invention, and are not used to limit the present invention.

[0035] It should be noted that the following detailed descriptions are all exemplary and are intended to provide further descriptions of the present invention. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention belongs.

[0036] It should be noted that the terms used here are only for describing specific embodiments, and are not intended to limit the exemplary embodiments according to the present invention. As used here, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and " / " or "include" are used in this specification, they indicate the presence of features, steps, operations and / or their combinations.

[0037] In the experimental methods of the following examples, unless otherwise specified, they are all conventional methods. The materials, reagents, etc. used in the following examples, unless otherwise specified, can all be obtained through commercial channels. Among them, the sources of several main experimental raw materials are as follows: graphene oxide (AR, JGC Catalysts & Chemicals), 3-amino-1,2-propanediol (AR, TCI Chemical Industry), calcium chloride (AR, Sinopharm Chemical Reagent), poly(2-acrylamido-2-methylpropanesulfonic acid) (AR, Merck Sigma), sodium hexadecylsulfonate, sodium lauryl sulfosuccinate (AR, Shengke Biochemical).

[0038] Example 1:

[0039] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.5 g of graphene oxide (GO) and ultrasonically disperse it in 100 g of deionized water for 1 h to form a GO dispersion; under stirring conditions, add 0.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 50 °C for 6 h; add 0.5 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 2 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0040] (2) Preparation of calcium-based nano modifier calcium-based poly sulfonic acid Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 0.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 15 min; centrifuge the above suspension at 3000 r / min for 15 min, discard the supernatant, and wash the solid with water 2 times; dry the washed white solid at 60 °C to make a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly sulfonic acid Ca-PAMPS.

[0041] (3) Weigh 0.2 g of sodium hexadecylsulfonate and 0.2 g of potassium chloride, dissolve them in 100 mL of deionized water, add them to 40 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium-based poly sulfonic acid Ca-PAMPS powder in sequence, and disperse them with an ultrasonic disperser for 20 min to obtain a high-temperature and alkali-resistant composite nano scale inhibitor.

[0042] As Figure 1 shown, the stretching vibration of -OH in the infrared spectrum is at 3416 cm -1 and that of 2919 cm-1 、The peak at 2850 cm -1 is the C-H stretching vibration peak of -CH 2 - in, and the peak at 1717 cm -1 is the stretching vibration peak of C=O. The peak at 1623 cm -1 is for the stretching vibration peak of C=C on the retained graphene sp 2 hybridized structural framework, and the C-N stretching vibration peak appears at 1403 cm -1 . Meanwhile, the C-N stretching vibration peak appears at 1220 cm -1 and the stretching vibration peaks of naphthalene ring and sulfonic acid group appear at 1050 cm -1 respectively.

[0043] Example 2:

[0044] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.55 g of graphene oxide (GO) and ultrasonically disperse it in 100 g of deionized water for 1 h to form a GO dispersion; under stirring conditions, add 0.75 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 50 °C for 6 h; add 0.5 g of sodium chloride to the reaction mixture and stir to disperse, then centrifuge at 1000 r / min for 20 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 2 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0045] (2) Preparation of calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 0.75 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 15 min; centrifuge the above suspension at 3000 r / min for 5 min, discard the upper clear liquid, and wash the solid with water 2 times; dry the washed white solid at 60 °C to make Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS.

[0046] (3) Weigh 0.3 g of sodium hexadecylsulfonate and 0.5 g of potassium chloride and dissolve them in 100 mL of deionized water, heat it to 50 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS powder in sequence, and use an ultrasonic disperser to disperse for 10 min to prepare a high-temperature and alkali-resistant composite nano-scale scale inhibitor.

[0047] Example 3:

[0048] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.6 g of graphene oxide (GO) and ultrasonically disperse it in 120 g of deionized water for 1.5 h to form a GO dispersion; under stirring conditions, add 1.0 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min, and continue to react at 60 °C for 5 h; add 1.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0049] (2) Preparation of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 20 min; centrifuge the above suspension at 3000 r / min for 10 min, discard the supernatant, and wash the solid with water 2 times; dry the washed white solid at 70 °C to make a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS.

[0050] (3) Weigh 0.1 g of sodium lauryl sulfosuccinate and 0.3 g of sodium chloride and dissolve them in 100 mL of deionized water, heat it to 50 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS powder in sequence, and disperse them with an ultrasonic disperser for 20 min to obtain a high-temperature and alkali-resistant composite nano-scale scale inhibitor.

[0051] Example 4:

[0052] (1)Preparation of modified graphene oxide nano AP-GO: Take 0.7 g of graphene oxide (GO) and ultrasonically disperse it in 150 g of deionized water for 1.5 h to form a GO dispersion; under stirring conditions, add 1.25 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min, and continue to react at 70 °C for 5 h; add 1.5 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 2000 r / min for 15 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0053] (2)Preparation of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 30 min; centrifuge the above suspension at 3000 r / min for 10 min, discard the supernatant, and wash the solid with water 3 times; dry the washed white solid at 70 °C to make Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS.

[0054] (3)Weigh 0.2 g of sodium lauryl sulfosuccinate and 0.3 g of sodium chloride and dissolve them in 100 mL of deionized water, add them to 60 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.3 g of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS powder in sequence, and disperse them with an ultrasonic disperser for 20 min to obtain a high-temperature and alkali-resistant composite nano-scale scale inhibitor.

[0055] Example 5:

[0056] (1)Preparation of modified graphene oxide nano AP-GO: Take 0.8 g of graphene oxide (GO) and ultrasonically disperse it in 150 g of deionized water for 2 h to form a GO dispersion; under stirring conditions, add 1.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 80 °C for 4 h; add 2.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 2000 r / min for 10 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0057] (2)Preparation of calcium-based nano modifier calcium poly-sulfonic acid Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continuously stir for 30 min; centrifuge the above suspension at 2000 r / min for 20 min, discard the supernatant, and wash the solid with water 3 times; dry the washed white solid at 80 °C to obtain Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly-sulfonic acid Ca-PAMPS.

[0058] (3)Weigh 0.1 g of sodium hexadecyl sulfonate, 0.1 g of sodium lauryl sulfosuccinate, and 0.3 g of potassium chloride and dissolve them in 100 mL of deionized water. Use a constant temperature water bath to heat it to 60 °C, then sequentially add 0.05 g of modified graphene oxide nano AP-GO powder and 0.3 g of calcium-based nano modifier calcium poly-sulfonic acid Ca-PAMPS powder, and use an ultrasonic disperser to disperse for 30 min to obtain a high-temperature and alkali-resistant composite nano-scale scale inhibitor.

[0059] Example 6:

[0060] (1)Preparation of modified graphene oxide nano AP-GO: Take 1.0 g of graphene oxide (GO) and ultrasonically disperse it in 200 g of deionized water for 2 h to form a GO dispersion; under stirring conditions, add 2.0 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min, and continue to react at 80 °C for 4 h; add 2.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 2000 r / min for 10 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0061] (2)Preparation of calcium-based nano modifier calcium poly-sulfonic acid Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, add the PAMPS solution to the calcium chloride solution at a rate of 5 mL / min to produce a white suspension, and continuously stir for 30 min; centrifuge the above suspension at 2000 r / min for 20 min, discard the supernatant, and wash the solid with water 3 times; dry the washed white solid at 80 °C to obtain Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly-sulfonic acid Ca-PAMPS.

[0062] (3) Weigh 0.2 g of sodium hexadecyl sulfonate, 0.2 g of disodium lauryl sulfosuccinate, and 0.3 g of sodium chloride, dissolve them in 100 mL of deionized water, heat it to 60 °C using a constant temperature water bath, then successively add 0.05 g of modified graphene oxide nano AP-GO powder and 0.3 g of calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS powder, and use an ultrasonic disperser to disperse for 30 min to obtain a high-temperature and alkali-resistant composite nano-scale scale inhibitor.

[0063] Comparative Example 1:

[0064] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.5 g of graphene oxide (GO) and ultrasonically disperse it in 100 g of deionized water for 1 h to form a GO dispersion; under stirring conditions, add 0.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 50 °C for 6 h; add 0.5 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 twice to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0065] (2) Weigh 0.2 g of sodium hexadecyl sulfonate and 0.2 g of potassium chloride, dissolve them in 100 mL of deionized water, heat it to 40 °C using a constant temperature water bath, then add 0.25 g of modified graphene oxide nano AP-GO powder, and use an ultrasonic disperser to disperse for 10 min to obtain a scale inhibitor.

[0066] Comparative Example 2:

[0067] (1) Preparation of calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS: Take 0.5 g of calcium chloride and dissolve it in 100 g of deionized water to form a calcium chloride solution, take 0.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and dissolve it in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 15 min; centrifuge the above suspension at 3000 r / min for 15 min, discard the supernatant, and wash the solid twice with water; dry the washed white solid at 60 °C to obtain a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS.

[0068] (2) Weigh 0.2 g of sodium hexadecyl sulfonate and 0.2 g of potassium chloride, dissolve them in 100 mL of deionized water, heat it to 40 °C using a constant temperature water bath, then add 0.25 g of calcium-based nano-modifier calcium poly(2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS powder, and disperse it for 10 min using an ultrasonic disperser to obtain a scale inhibitor.

[0069] Comparative Example 3:

[0070] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.5 g of graphene oxide (GO) and ultrasonically disperse it in 100 g of deionized water for 1 h to form a GO dispersion; under stirring conditions, add 0.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 50 °C for 6 h; add 0.5 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the upper clear liquid, wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, and repeat 2 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0071] (2) Preparation of calcium-based nano-modifier calcium poly(2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS: Take 0.5 g of calcium chloride and dissolve it in 100 g of deionized water to form a calcium chloride solution, take 0.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and dissolve it in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 15 min; centrifuge the above suspension at 3000 r / min for 15 min, discard the upper clear liquid, and wash the solid with water 2 times; dry the washed white solid at 60 °C to obtain a Ca-PAMPS solid, which is the calcium-based nano-modifier calcium poly(2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS.

[0072] (3) Weigh 0.4 g of sodium hexadecyl sulfonate and dissolve it in 100 mL of deionized water, heat it to 40 °C using a constant temperature water bath, then successively add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano-modifier calcium poly(2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS powder, and disperse it for 20 min using an ultrasonic disperser to obtain a high-temperature and alkali-resistant composite nano-scale inhibitor.

[0073] Comparative Example 4:

[0074] (1)Preparation of modified graphene oxide nano AP-GO: Take 0.5 g of graphene oxide (GO) and ultrasonically disperse it in 100 g of deionized water for 1 h to form a GO dispersion; Under stirring conditions, add 0.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 50 °C for 6 h; Add 0.5 g of sodium chloride to the reacted mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 2 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0075] (2)Preparation of calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 0.5 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; Continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continuously stir for 15 min; Centrifuge the above suspension at 3000 r / min for 15 min, discard the upper clear liquid, and wash the solid with water 2 times; Dry the washed white solid at 60 °C to make a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS.

[0076] (3)Weigh 0.4 g of potassium chloride and dissolve it in 100 mL of deionized water, add it to 40 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium-based poly-sulfonic acid Ca-PAMPS powder in sequence, and disperse it with an ultrasonic disperser for 20 min to obtain a scale inhibitor.

[0077] Control Example 5:

[0078] (1)Preparation of modified graphene oxide nano AP-GO: Take 0.6 g of graphene oxide (GO) and ultrasonically disperse it in 120 g of deionized water for 1.5 h to form a GO dispersion; Under stirring conditions, add 1.0 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min, and continue to react at 60 °C for 5 h; Add 1.0 g of sodium chloride to the reacted mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0079] (2) Weigh 0.1 g of sodium lauryl sulfosuccinate and 0.3 g of sodium chloride, dissolve them in 100 mL of deionized water, heat the solution to 50 °C using a constant temperature water bath, then add 0.25 g of the modified graphene oxide nano AP-GO powder, and disperse it for 20 min using an ultrasonic disperser to obtain the scale inhibitor.

[0080] Comparative Example 6:

[0081] (1) Preparation of calcium-based nano modifier Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and while stirring, add the PAMPS solution to the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue stirring for 20 min; centrifuge the above suspension at 3000 r / min for 10 min, discard the supernatant, and wash the solid with water 2 times; dry the washed white solid at 70 °C to obtain the Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly sulfonate Ca-PAMPS.

[0082] (2) Weigh 0.1 g of sodium lauryl sulfosuccinate and 0.3 g of sodium chloride, dissolve them in 100 mL of deionized water, heat the solution to 50 °C using a constant temperature water bath, then add 0.25 g of the calcium-based nano modifier calcium poly sulfonate Ca-PAMPS powder, and disperse it for 20 min using an ultrasonic disperser to obtain the scale inhibitor.

[0083] Comparative Example 7:

[0084] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.6 g of graphene oxide (GO) and ultrasonically disperse it in 120 g of deionized water for 1.5 h to form a GO dispersion; under stirring conditions, add 1.0 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min, and continue to react at 60 °C for 5 h; add 1.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the supernatant, and wash the lower layer solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1, repeat 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0085] (2)Preparation of calcium-based nano modifier Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continuously stir for 20 min; centrifuge the above suspension at 3000 r / min for 10 min, discard the supernatant, and wash the solid with water twice; dry the washed white solid at 70 °C to obtain Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly sulfonate Ca-PAMPS.

[0086] (3)Weigh 0.4 g of sodium dodecyl sulfosuccinate and dissolve it in 100 mL of deionized water, heat it to 50 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium poly sulfonate Ca-PAMPS powder in sequence, and disperse them with an ultrasonic disperser for 20 min to obtain a scale inhibitor.

[0087] Comparative Example 8:

[0088] (1)Preparation of modified graphene oxide nano AP-GO: Take 0.6 g of graphene oxide (GO) and ultrasonically disperse it in 120 g of deionized water for 1.5 h to form a GO dispersion; add 1.0 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 10 mL / min under stirring conditions, and continue to react at 60 °C for 5 h; add 1.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 1000 r / min for 20 min, discard the supernatant, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0089] (2)Preparation of calcium-based nano modifier Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continuously stir for 20 min; centrifuge the above suspension at 3000 r / min for 10 min, discard the supernatant, and wash the solid with water twice; dry the washed white solid at 70 °C to obtain Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly sulfonate Ca-PAMPS.

[0090] (3) Weigh 0.4 g of sodium chloride and dissolve it in 100 mL of deionized water. Add it to 50 °C using a constant temperature water bath. Then, add 0.05 g of modified graphene oxide nano AP-GO powder and 0.2 g of calcium-based nano modifier calcium-based poly sulfonic acid Ca-PAMPS powder in sequence, and disperse them with an ultrasonic disperser for 20 min to obtain a scale inhibitor.

[0091] Comparative Example 9:

[0092] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.8 g of graphene oxide (GO) and ultrasonically disperse it in 150 g of deionized water for 2 h to form a GO dispersion; under stirring conditions, add 1.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 80 °C for 4 h; add 2.0 g of sodium chloride to the reacted mixture and stir to disperse it, then centrifuge at 2000 r / min for 10 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0093] (2) Weigh 0.1 g of sodium hexadecyl sulfonate, 0.1 g of sodium lauryl sulfosuccinate, and 0.3 g of potassium chloride and dissolve them in 100 mL of deionized water. Add it to 60 °C using a constant temperature water bath. Then, add 0.35 g of modified graphene oxide nano AP-GO powder, and disperse it with an ultrasonic disperser for 30 min to obtain a scale inhibitor.

[0094] Comparative Example 10:

[0095] (1) Preparation of calcium-based nano modifier Ca-PAMPS: Take 0.5 g of calcium chloride and dissolve it in 100 g of deionized water to form a calcium chloride solution. Take 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) and dissolve it in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 30 min; centrifuge the above suspension at 2000 r / min for 20 min, discard the upper clear liquid, and wash the solid with water for 3 times; dry the washed white solid at 80 °C to make Ca-PAMPS solid.

[0096] (3) Weigh 0.1 g of sodium hexadecyl sulfonate, 0.1 g of sodium lauryl sulfosuccinate, and 0.3 g of potassium chloride and dissolve them in 100 mL of deionized water. Add it to 60 °C using a constant temperature water bath. Then, add 0.35 g of Ca-PAMPS powder, and disperse it with an ultrasonic disperser for 30 min to obtain a high-temperature and alkali-resistant composite nano scale inhibitor.

[0097] Comparative Example 11:

[0098] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.8 g of graphene oxide (GO) and ultrasonically disperse it in 150 g of deionized water for 2 h to form a GO dispersion; under stirring conditions, add 1.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 80 °C for 4 h; add 2.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 2000 r / min for 10 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0099] (2) Preparation of calcium-based nano modifier calcium poly (2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly (2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continue to stir for 30 min; centrifuge the above suspension at 2000 r / min for 20 min, discard the upper clear liquid, and wash the solid with water 3 times; dry the washed white solid at 80 °C to obtain a Ca-PAMPS solid, which is the calcium-based nano modifier calcium poly (2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS.

[0100] (3) Weigh 0.25 g of sodium hexadecylsulfonate and 0.25 g of sodium lauryl sulfosuccinate and dissolve them in 100 mL of deionized water, heat it to 60 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.3 g of calcium-based nano modifier calcium poly (2-acrylamido-2-methylpropanesulfonic acid) Ca-PAMPS powder in sequence, and use an ultrasonic disperser to disperse for 30 min to obtain a scale inhibitor.

[0101] Comparative Example 12:

[0102] (1) Preparation of modified graphene oxide nano AP-GO: Take 0.8 g of graphene oxide (GO) and ultrasonically disperse it in 150 g of deionized water for 2 h to form a GO dispersion; under stirring conditions, add 1.5 g of 3-amino-1,2-propanediol (AP) to the GO dispersion at a rate of 5 mL / min, and continue to react at 80 °C for 4 h; add 2.0 g of sodium chloride to the reaction mixture and stir to disperse it, then centrifuge at 2000 r / min for 10 min, discard the upper clear liquid, and wash the lower solid with a mixed solution of ethanol and deionized water with a volume ratio of 1:1 for 3 times to obtain 3-amino-1,2-propanediol modified graphene oxide nano (AP-GO).

[0103] (2) Preparation of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS: Dissolve 0.5 g of calcium chloride in 100 g of deionized water to form a calcium chloride solution, and dissolve 1.2 g of poly(2-acrylamido-2-methylpropanesulfonic acid) (PAMPS) in 100 g of deionized water to form a PAMPS solution; Continuously stir the calcium chloride solution, and at the same time, drop the PAMPS solution into the calcium chloride solution at a rate of 10 mL / min to produce a white suspension, and continuously stir for 30 min; Centrifuge the above suspension at 2000 r / min for 20 min, discard the supernatant, and wash the solid with water 3 times; Dry the washed white solid at 80 °C to obtain a Ca-PAMPS solid, which is the calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS.

[0104] (3) Weigh 0.5 g of potassium chloride and dissolve it in 100 mL of deionized water, add it to 60 °C with a constant temperature water bath, then add 0.05 g of modified graphene oxide nano AP-GO powder and 0.3 g of calcium-based nano modifier calcium-based poly(sulfonic acid) Ca-PAMPS powder in sequence, and use an ultrasonic disperser to prepare a scale inhibitor in 30 min.

[0105] Performance comparison:

[0106] Compare the scale inhibition effects of the scale inhibitors in Examples 1 to 6, Comparative Examples 1 to 12, and commercially available products (polyepoxysuccinic acid sodium, sodium polyaspartate). Test method: Prepare a 5000 mg / L calcium chloride solution, add scale inhibitors with different concentrations (10 mg / L, 20 mg / L, 40 mg / L), and then mix it with simulated formation brine (10001.6 mg / L potassium ion, 76000.0 mg / L sodium ion, 54.3 mg / L calcium ion, 68.3 mg / L magnesium ion, 75179.7 mg / L chloride ion, 11825.0 mg / L sulfate ion, 36377.7 mg / L bicarbonate ion, total salinity 209506.5 mg / L, pH = 8.3) in a ratio of 1:1. Place the solution in a constant temperature drying oven at 100 °C and 150 °C and let it stand for 24 h, then take it out and test the scale inhibition rate. The specific results are shown in Table 1 and Table 2 respectively.

[0107] Table 1 Comparison of scale inhibitor stability and scale inhibition rate under 100 °C

[0108] 。

[0109] Table 2 Test results of scale inhibition rate of different scale inhibitor concentrations (150 °C)

[0110] 。

[0111] As can be seen from the comparative test results in Table 1, the high-temperature resistant composite nano-scale inhibitor of the present invention has excellent scale inhibition effect. At 100 °C and the same concentration, the scale inhibition rates of the separately modified graphene oxide nano AP-GO and the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS nano-fluid scale inhibitor under the same dosage in the comparative examples are respectively lower than 40% and 70%. When any one of the components such as modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, surfactant, and inorganic salt is missing, its scale inhibition rate and stability will decrease significantly. While in the examples, the scale inhibition rate of the high-temperature resistant composite nano-scale inhibitor is in the range of 10 - 40 mg / L, and the scale inhibition rate is greater than 80%, up to 94.2% at most, indicating that each substance in the components has an obvious synergistic scale inhibition and efficiency-enhancing effect. At the same time, the addition of inorganic salt can improve the product stability to more than 90 days. As can be seen from Table 2, the temperature-resistant composite nano-scale inhibitors described in Examples 1 to 6 can reach a temperature resistance of 150 °C with good scale inhibition effect when the dosage is appropriately increased.

[0112] In summary, the present invention discloses a high-temperature resistant composite nano-fluid scale inhibitor and its preparation method, belonging to the technical field of oilfield chemistry; this composite nano-fluid scale inhibitor is prepared from modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, surfactant, inorganic salt, and deionized water; the calcium-based nano modifier calcium-based polysulfonic acid contains a large number of sulfonic acid, carboxylic acid, and hydroxyl groups, has strong hydrophilicity, calcium ion tolerance, and calcium ion chelation, and has a good scale inhibition effect on calcium carbonate scale and barium sulfate scale; at the same time, the modified graphene oxide nano has large-scale conjugated rings, a large number of carboxylic acid and hydroxyl groups, and synergistically enhances the efficiency with calcium-based polysulfonic acid under the action of anion shielding and steric hindrance effect. By applying the synergistic effect of modified graphene oxide nano, calcium-based polysulfonic acid, surfactant, and inorganic salt, the high-temperature resistance and scale inhibition performance of the nano-scale inhibitor are further improved, having a good scale inhibition effect, effectively solving the problem of scale formation in oilfield water injection and fracturing flowback, and having a good promotion prospect.

[0113] At this point, those skilled in the art recognize that although the embodiments of the present invention have been shown and described in detail herein, many other variations or modifications that conform to the principles of the present invention can still be directly determined or derived from the content disclosed in the present invention without departing from the spirit and scope of the present invention. Therefore, the scope of the present invention should be understood and determined to cover all these other variations or modifications.

Claims

1. A high temperature resistant composite nanofluid scale inhibitor, characterized in that: The composite nanofluid antiscalant comprises: Modified graphene oxide nano AP-GO, calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS, surfactant, inorganic salt and deionized water; The mass concentration of the modified graphene oxide nano AP-GO in the scale inhibitor is 0.01-0.1%; The mass concentration of the surfactant in the scale inhibitor is 0.1 to 0.4%; The mass concentration of the inorganic salt in the scale inhibitor is 0.3 to 0.5%; The mass ratio of the modified graphene oxide nano AP-GO to the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS is 1:4 to 1:6; The inorganic salt is one or more of potassium chloride and sodium chloride; The surfactant is one or more of sodium dodecylbenzene sulfonate, sodium hexadecyl sulfate, sodium hexadecyl sulfonate, sodium lauryl polyoxyethylene ether sulfate and disodium lauryl sulfosuccinate; The specific preparation method of the modified graphene oxide nano AP-GO is: 0.5-1.0 g of graphene oxide GO is ultrasonically dispersed in 100-200 g of deionized water for 1-2 h to form a GO dispersion; 3-amino-1,2-propylene glycol AP is added to the GO dispersion at 5-10 mL / min under stirring conditions, and the reaction is continued at 50-80° C. for 4-6 h; 0.5-2 g of sodium chloride is added to the reaction mixture, stirred and dispersed, and then centrifuged at 1000-2000 r / min for 10-20 min, the upper clear liquid is discarded, and the lower solid is washed, and the process is repeated 2-3 times to obtain 3-amino-1,2-propylene glycol-modified graphene oxide nano AP-GO; The mass ratio of graphene oxide GO to 3-amino-1,2-propylene glycol AP is 1:1 to 1:4; The specific preparation method of the calcium-based nano-modifier calcium-based polysulfonic acid Ca-PAMPS is as follows: Calcium chloride is dissolved in water to form a calcium chloride solution, wherein the mass concentration of the calcium chloride solution is 0.1-1%; Dissolve poly (2-acrylamide-2-methylpropanesulfonic acid) (PAMPS) in water to form a PAMPS solution, wherein the mass concentration of the PAMPS solution is 0.5 to 1.5%; The calcium chloride solution is continuously stirred, and the PAMPS solution is added dropwise to the calcium chloride solution at a rate of 5 to 10 mL / min to produce a white suspension, which is continuously stirred for 15 to 30 min; the suspension is centrifuged at 1000 to 3000 r / min for 5 to 20 min, the supernatant is discarded, and the solid is washed with water 2 to 3 times; the washed white solid is dried at 50-80° C. to prepare a Ca-PAMPS solid, which is a calcium-based nano-modifier calcium-based polysulfonic acid Ca-PAMPS; The mass ratio of the calcium chloride to poly (2-acrylamide-2-methylpropane sulfonic acid) PAMPS is 1:1 to 1:

3.

2. A high temperature resistant composite nanofluid antiscalant as claimed in claim 1, characterized in that: The surfactants are sodium hexadecyl sulfonate and disodium lauryl sulfosuccinate.

3. A high temperature resistant composite nanofluid antiscalant as claimed in claim 1, characterized in that: In the specific preparation method of the modified graphene oxide nano AP-GO, a mixed solution of ethanol and deionized water in a volume ratio of 1:1 is used to wash the lower layer solid.

4. The high temperature resistant composite nanofluid antiscalant according to claim 1, characterized in that: The preparation method of the scale inhibitor is specifically as follows: The modified graphene oxide nano AP-GO and the calcium-based nano modifier calcium-based polysulfonic acid Ca-PAMPS are mixed with an inorganic salt, a surfactant and deionized water according to the concentration and mass ratio, and then heated at 40 to 60° C. and ultrasonically dispersed for 10 to 30 minutes to obtain the high-temperature resistant composite nanofluid scale inhibitor.

Images